diff --git a/.clang-format b/.clang-format index 1d5da22e0ba5..e6080f5834a3 100644 --- a/.clang-format +++ b/.clang-format @@ -323,7 +323,6 @@ ForEachMacros: - 'protocol_for_each_card' - 'protocol_for_each_dev' - 'queue_for_each_hw_ctx' - - 'radix_tree_for_each_contig' - 'radix_tree_for_each_slot' - 'radix_tree_for_each_tagged' - 'rbtree_postorder_for_each_entry_safe' diff --git a/.mailmap b/.mailmap index 285e09645b31..89f532caf639 100644 --- a/.mailmap +++ b/.mailmap @@ -119,6 +119,13 @@ Mark Brown Mark Yao Martin Kepplinger Martin Kepplinger +Matthew Wilcox +Matthew Wilcox +Matthew Wilcox +Matthew Wilcox +Matthew Wilcox +Matthew Wilcox +Matthew Wilcox Matthieu CASTET Mauro Carvalho Chehab Mauro Carvalho Chehab diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst index 29c790f571a5..3adee82be311 100644 --- a/Documentation/core-api/index.rst +++ b/Documentation/core-api/index.rst @@ -21,6 +21,7 @@ Core utilities local_ops workqueue genericirq + xarray flexible-arrays librs genalloc diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst new file mode 100644 index 000000000000..a4e705108f42 --- /dev/null +++ b/Documentation/core-api/xarray.rst @@ -0,0 +1,435 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +====== +XArray +====== + +:Author: Matthew Wilcox + +Overview +======== + +The XArray is an abstract data type which behaves like a very large array +of pointers. It meets many of the same needs as a hash or a conventional +resizable array. Unlike a hash, it allows you to sensibly go to the +next or previous entry in a cache-efficient manner. In contrast to a +resizable array, there is no need to copy data or change MMU mappings in +order to grow the array. It is more memory-efficient, parallelisable +and cache friendly than a doubly-linked list. It takes advantage of +RCU to perform lookups without locking. + +The XArray implementation is efficient when the indices used are densely +clustered; hashing the object and using the hash as the index will not +perform well. The XArray is optimised for small indices, but still has +good performance with large indices. If your index can be larger than +``ULONG_MAX`` then the XArray is not the data type for you. The most +important user of the XArray is the page cache. + +Each non-``NULL`` entry in the array has three bits associated with +it called marks. Each mark may be set or cleared independently of +the others. You can iterate over entries which are marked. + +Normal pointers may be stored in the XArray directly. They must be 4-byte +aligned, which is true for any pointer returned from :c:func:`kmalloc` and +:c:func:`alloc_page`. It isn't true for arbitrary user-space pointers, +nor for function pointers. You can store pointers to statically allocated +objects, as long as those objects have an alignment of at least 4. + +You can also store integers between 0 and ``LONG_MAX`` in the XArray. +You must first convert it into an entry using :c:func:`xa_mk_value`. +When you retrieve an entry from the XArray, you can check whether it is +a value entry by calling :c:func:`xa_is_value`, and convert it back to +an integer by calling :c:func:`xa_to_value`. + +Some users want to store tagged pointers instead of using the marks +described above. They can call :c:func:`xa_tag_pointer` to create an +entry with a tag, :c:func:`xa_untag_pointer` to turn a tagged entry +back into an untagged pointer and :c:func:`xa_pointer_tag` to retrieve +the tag of an entry. Tagged pointers use the same bits that are used +to distinguish value entries from normal pointers, so each user must +decide whether they want to store value entries or tagged pointers in +any particular XArray. + +The XArray does not support storing :c:func:`IS_ERR` pointers as some +conflict with value entries or internal entries. + +An unusual feature of the XArray is the ability to create entries which +occupy a range of indices. Once stored to, looking up any index in +the range will return the same entry as looking up any other index in +the range. Setting a mark on one index will set it on all of them. +Storing to any index will store to all of them. Multi-index entries can +be explicitly split into smaller entries, or storing ``NULL`` into any +entry will cause the XArray to forget about the range. + +Normal API +========== + +Start by initialising an XArray, either with :c:func:`DEFINE_XARRAY` +for statically allocated XArrays or :c:func:`xa_init` for dynamically +allocated ones. A freshly-initialised XArray contains a ``NULL`` +pointer at every index. + +You can then set entries using :c:func:`xa_store` and get entries +using :c:func:`xa_load`. xa_store will overwrite any entry with the +new entry and return the previous entry stored at that index. You can +use :c:func:`xa_erase` instead of calling :c:func:`xa_store` with a +``NULL`` entry. There is no difference between an entry that has never +been stored to and one that has most recently had ``NULL`` stored to it. + +You can conditionally replace an entry at an index by using +:c:func:`xa_cmpxchg`. Like :c:func:`cmpxchg`, it will only succeed if +the entry at that index has the 'old' value. It also returns the entry +which was at that index; if it returns the same entry which was passed as +'old', then :c:func:`xa_cmpxchg` succeeded. + +If you want to only store a new entry to an index if the current entry +at that index is ``NULL``, you can use :c:func:`xa_insert` which +returns ``-EEXIST`` if the entry is not empty. + +You can enquire whether a mark is set on an entry by using +:c:func:`xa_get_mark`. If the entry is not ``NULL``, you can set a mark +on it by using :c:func:`xa_set_mark` and remove the mark from an entry by +calling :c:func:`xa_clear_mark`. You can ask whether any entry in the +XArray has a particular mark set by calling :c:func:`xa_marked`. + +You can copy entries out of the XArray into a plain array by calling +:c:func:`xa_extract`. Or you can iterate over the present entries in +the XArray by calling :c:func:`xa_for_each`. You may prefer to use +:c:func:`xa_find` or :c:func:`xa_find_after` to move to the next present +entry in the XArray. + +Calling :c:func:`xa_store_range` stores the same entry in a range +of indices. If you do this, some of the other operations will behave +in a slightly odd way. For example, marking the entry at one index +may result in the entry being marked at some, but not all of the other +indices. Storing into one index may result in the entry retrieved by +some, but not all of the other indices changing. + +Finally, you can remove all entries from an XArray by calling +:c:func:`xa_destroy`. If the XArray entries are pointers, you may wish +to free the entries first. You can do this by iterating over all present +entries in the XArray using the :c:func:`xa_for_each` iterator. + +ID assignment +------------- + +You can call :c:func:`xa_alloc` to store the entry at any unused index +in the XArray. If you need to modify the array from interrupt context, +you can use :c:func:`xa_alloc_bh` or :c:func:`xa_alloc_irq` to disable +interrupts while allocating the ID. Unlike :c:func:`xa_store`, allocating +a ``NULL`` pointer does not delete an entry. Instead it reserves an +entry like :c:func:`xa_reserve` and you can release it using either +:c:func:`xa_erase` or :c:func:`xa_release`. To use ID assignment, the +XArray must be defined with :c:func:`DEFINE_XARRAY_ALLOC`, or initialised +by passing ``XA_FLAGS_ALLOC`` to :c:func:`xa_init_flags`, + +Memory allocation +----------------- + +The :c:func:`xa_store`, :c:func:`xa_cmpxchg`, :c:func:`xa_alloc`, +:c:func:`xa_reserve` and :c:func:`xa_insert` functions take a gfp_t +parameter in case the XArray needs to allocate memory to store this entry. +If the entry is being deleted, no memory allocation needs to be performed, +and the GFP flags specified will be ignored. + +It is possible for no memory to be allocatable, particularly if you pass +a restrictive set of GFP flags. In that case, the functions return a +special value which can be turned into an errno using :c:func:`xa_err`. +If you don't need to know exactly which error occurred, using +:c:func:`xa_is_err` is slightly more efficient. + +Locking +------- + +When using the Normal API, you do not have to worry about locking. +The XArray uses RCU and an internal spinlock to synchronise access: + +No lock needed: + * :c:func:`xa_empty` + * :c:func:`xa_marked` + +Takes RCU read lock: + * :c:func:`xa_load` + * :c:func:`xa_for_each` + * :c:func:`xa_find` + * :c:func:`xa_find_after` + * :c:func:`xa_extract` + * :c:func:`xa_get_mark` + +Takes xa_lock internally: + * :c:func:`xa_store` + * :c:func:`xa_insert` + * :c:func:`xa_erase` + * :c:func:`xa_erase_bh` + * :c:func:`xa_erase_irq` + * :c:func:`xa_cmpxchg` + * :c:func:`xa_store_range` + * :c:func:`xa_alloc` + * :c:func:`xa_alloc_bh` + * :c:func:`xa_alloc_irq` + * :c:func:`xa_destroy` + * :c:func:`xa_set_mark` + * :c:func:`xa_clear_mark` + +Assumes xa_lock held on entry: + * :c:func:`__xa_store` + * :c:func:`__xa_insert` + * :c:func:`__xa_erase` + * :c:func:`__xa_cmpxchg` + * :c:func:`__xa_alloc` + * :c:func:`__xa_set_mark` + * :c:func:`__xa_clear_mark` + +If you want to take advantage of the lock to protect the data structures +that you are storing in the XArray, you can call :c:func:`xa_lock` +before calling :c:func:`xa_load`, then take a reference count on the +object you have found before calling :c:func:`xa_unlock`. This will +prevent stores from removing the object from the array between looking +up the object and incrementing the refcount. You can also use RCU to +avoid dereferencing freed memory, but an explanation of that is beyond +the scope of this document. + +The XArray does not disable interrupts or softirqs while modifying +the array. It is safe to read the XArray from interrupt or softirq +context as the RCU lock provides enough protection. + +If, for example, you want to store entries in the XArray in process +context and then erase them in softirq context, you can do that this way:: + + void foo_init(struct foo *foo) + { + xa_init_flags(&foo->array, XA_FLAGS_LOCK_BH); + } + + int foo_store(struct foo *foo, unsigned long index, void *entry) + { + int err; + + xa_lock_bh(&foo->array); + err = xa_err(__xa_store(&foo->array, index, entry, GFP_KERNEL)); + if (!err) + foo->count++; + xa_unlock_bh(&foo->array); + return err; + } + + /* foo_erase() is only called from softirq context */ + void foo_erase(struct foo *foo, unsigned long index) + { + xa_lock(&foo->array); + __xa_erase(&foo->array, index); + foo->count--; + xa_unlock(&foo->array); + } + +If you are going to modify the XArray from interrupt or softirq context, +you need to initialise the array using :c:func:`xa_init_flags`, passing +``XA_FLAGS_LOCK_IRQ`` or ``XA_FLAGS_LOCK_BH``. + +The above example also shows a common pattern of wanting to extend the +coverage of the xa_lock on the store side to protect some statistics +associated with the array. + +Sharing the XArray with interrupt context is also possible, either +using :c:func:`xa_lock_irqsave` in both the interrupt handler and process +context, or :c:func:`xa_lock_irq` in process context and :c:func:`xa_lock` +in the interrupt handler. Some of the more common patterns have helper +functions such as :c:func:`xa_erase_bh` and :c:func:`xa_erase_irq`. + +Sometimes you need to protect access to the XArray with a mutex because +that lock sits above another mutex in the locking hierarchy. That does +not entitle you to use functions like :c:func:`__xa_erase` without taking +the xa_lock; the xa_lock is used for lockdep validation and will be used +for other purposes in the future. + +The :c:func:`__xa_set_mark` and :c:func:`__xa_clear_mark` functions are also +available for situations where you look up an entry and want to atomically +set or clear a mark. It may be more efficient to use the advanced API +in this case, as it will save you from walking the tree twice. + +Advanced API +============ + +The advanced API offers more flexibility and better performance at the +cost of an interface which can be harder to use and has fewer safeguards. +No locking is done for you by the advanced API, and you are required +to use the xa_lock while modifying the array. You can choose whether +to use the xa_lock or the RCU lock while doing read-only operations on +the array. You can mix advanced and normal operations on the same array; +indeed the normal API is implemented in terms of the advanced API. The +advanced API is only available to modules with a GPL-compatible license. + +The advanced API is based around the xa_state. This is an opaque data +structure which you declare on the stack using the :c:func:`XA_STATE` +macro. This macro initialises the xa_state ready to start walking +around the XArray. It is used as a cursor to maintain the position +in the XArray and let you compose various operations together without +having to restart from the top every time. + +The xa_state is also used to store errors. You can call +:c:func:`xas_error` to retrieve the error. All operations check whether +the xa_state is in an error state before proceeding, so there's no need +for you to check for an error after each call; you can make multiple +calls in succession and only check at a convenient point. The only +errors currently generated by the XArray code itself are ``ENOMEM`` and +``EINVAL``, but it supports arbitrary errors in case you want to call +:c:func:`xas_set_err` yourself. + +If the xa_state is holding an ``ENOMEM`` error, calling :c:func:`xas_nomem` +will attempt to allocate more memory using the specified gfp flags and +cache it in the xa_state for the next attempt. The idea is that you take +the xa_lock, attempt the operation and drop the lock. The operation +attempts to allocate memory while holding the lock, but it is more +likely to fail. Once you have dropped the lock, :c:func:`xas_nomem` +can try harder to allocate more memory. It will return ``true`` if it +is worth retrying the operation (i.e. that there was a memory error *and* +more memory was allocated). If it has previously allocated memory, and +that memory wasn't used, and there is no error (or some error that isn't +``ENOMEM``), then it will free the memory previously allocated. + +Internal Entries +---------------- + +The XArray reserves some entries for its own purposes. These are never +exposed through the normal API, but when using the advanced API, it's +possible to see them. Usually the best way to handle them is to pass them +to :c:func:`xas_retry`, and retry the operation if it returns ``true``. + +.. flat-table:: + :widths: 1 1 6 + + * - Name + - Test + - Usage + + * - Node + - :c:func:`xa_is_node` + - An XArray node. May be visible when using a multi-index xa_state. + + * - Sibling + - :c:func:`xa_is_sibling` + - A non-canonical entry for a multi-index entry. The value indicates + which slot in this node has the canonical entry. + + * - Retry + - :c:func:`xa_is_retry` + - This entry is currently being modified by a thread which has the + xa_lock. The node containing this entry may be freed at the end + of this RCU period. You should restart the lookup from the head + of the array. + + * - Zero + - :c:func:`xa_is_zero` + - Zero entries appear as ``NULL`` through the Normal API, but occupy + an entry in the XArray which can be used to reserve the index for + future use. + +Other internal entries may be added in the future. As far as possible, they +will be handled by :c:func:`xas_retry`. + +Additional functionality +------------------------ + +The :c:func:`xas_create_range` function allocates all the necessary memory +to store every entry in a range. It will set ENOMEM in the xa_state if +it cannot allocate memory. + +You can use :c:func:`xas_init_marks` to reset the marks on an entry +to their default state. This is usually all marks clear, unless the +XArray is marked with ``XA_FLAGS_TRACK_FREE``, in which case mark 0 is set +and all other marks are clear. Replacing one entry with another using +:c:func:`xas_store` will not reset the marks on that entry; if you want +the marks reset, you should do that explicitly. + +The :c:func:`xas_load` will walk the xa_state as close to the entry +as it can. If you know the xa_state has already been walked to the +entry and need to check that the entry hasn't changed, you can use +:c:func:`xas_reload` to save a function call. + +If you need to move to a different index in the XArray, call +:c:func:`xas_set`. This resets the cursor to the top of the tree, which +will generally make the next operation walk the cursor to the desired +spot in the tree. If you want to move to the next or previous index, +call :c:func:`xas_next` or :c:func:`xas_prev`. Setting the index does +not walk the cursor around the array so does not require a lock to be +held, while moving to the next or previous index does. + +You can search for the next present entry using :c:func:`xas_find`. This +is the equivalent of both :c:func:`xa_find` and :c:func:`xa_find_after`; +if the cursor has been walked to an entry, then it will find the next +entry after the one currently referenced. If not, it will return the +entry at the index of the xa_state. Using :c:func:`xas_next_entry` to +move to the next present entry instead of :c:func:`xas_find` will save +a function call in the majority of cases at the expense of emitting more +inline code. + +The :c:func:`xas_find_marked` function is similar. If the xa_state has +not been walked, it will return the entry at the index of the xa_state, +if it is marked. Otherwise, it will return the first marked entry after +the entry referenced by the xa_state. The :c:func:`xas_next_marked` +function is the equivalent of :c:func:`xas_next_entry`. + +When iterating over a range of the XArray using :c:func:`xas_for_each` +or :c:func:`xas_for_each_marked`, it may be necessary to temporarily stop +the iteration. The :c:func:`xas_pause` function exists for this purpose. +After you have done the necessary work and wish to resume, the xa_state +is in an appropriate state to continue the iteration after the entry +you last processed. If you have interrupts disabled while iterating, +then it is good manners to pause the iteration and reenable interrupts +every ``XA_CHECK_SCHED`` entries. + +The :c:func:`xas_get_mark`, :c:func:`xas_set_mark` and +:c:func:`xas_clear_mark` functions require the xa_state cursor to have +been moved to the appropriate location in the xarray; they will do +nothing if you have called :c:func:`xas_pause` or :c:func:`xas_set` +immediately before. + +You can call :c:func:`xas_set_update` to have a callback function +called each time the XArray updates a node. This is used by the page +cache workingset code to maintain its list of nodes which contain only +shadow entries. + +Multi-Index Entries +------------------- + +The XArray has the ability to tie multiple indices together so that +operations on one index affect all indices. For example, storing into +any index will change the value of the entry retrieved from any index. +Setting or clearing a mark on any index will set or clear the mark +on every index that is tied together. The current implementation +only allows tying ranges which are aligned powers of two together; +eg indices 64-127 may be tied together, but 2-6 may not be. This may +save substantial quantities of memory; for example tying 512 entries +together will save over 4kB. + +You can create a multi-index entry by using :c:func:`XA_STATE_ORDER` +or :c:func:`xas_set_order` followed by a call to :c:func:`xas_store`. +Calling :c:func:`xas_load` with a multi-index xa_state will walk the +xa_state to the right location in the tree, but the return value is not +meaningful, potentially being an internal entry or ``NULL`` even when there +is an entry stored within the range. Calling :c:func:`xas_find_conflict` +will return the first entry within the range or ``NULL`` if there are no +entries in the range. The :c:func:`xas_for_each_conflict` iterator will +iterate over every entry which overlaps the specified range. + +If :c:func:`xas_load` encounters a multi-index entry, the xa_index +in the xa_state will not be changed. When iterating over an XArray +or calling :c:func:`xas_find`, if the initial index is in the middle +of a multi-index entry, it will not be altered. Subsequent calls +or iterations will move the index to the first index in the range. +Each entry will only be returned once, no matter how many indices it +occupies. + +Using :c:func:`xas_next` or :c:func:`xas_prev` with a multi-index xa_state +is not supported. Using either of these functions on a multi-index entry +will reveal sibling entries; these should be skipped over by the caller. + +Storing ``NULL`` into any index of a multi-index entry will set the entry +at every index to ``NULL`` and dissolve the tie. Splitting a multi-index +entry into entries occupying smaller ranges is not yet supported. + +Functions and structures +======================== + +.. kernel-doc:: include/linux/xarray.h +.. kernel-doc:: lib/xarray.c diff --git a/MAINTAINERS b/MAINTAINERS index bfc9722a4932..a78d45755881 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -535,7 +535,7 @@ F: Documentation/hwmon/adt7475 F: drivers/hwmon/adt7475.c ADVANSYS SCSI DRIVER -M: Matthew Wilcox +M: Matthew Wilcox M: Hannes Reinecke L: linux-scsi@vger.kernel.org S: Maintained @@ -4393,7 +4393,7 @@ S: Maintained F: drivers/i2c/busses/i2c-diolan-u2c.c FILESYSTEM DIRECT ACCESS (DAX) -M: Matthew Wilcox +M: Matthew Wilcox M: Ross Zwisler M: Jan Kara L: linux-fsdevel@vger.kernel.org @@ -8697,7 +8697,7 @@ F: drivers/message/fusion/ F: drivers/scsi/mpt3sas/ LSILOGIC/SYMBIOS/NCR 53C8XX and 53C1010 PCI-SCSI drivers -M: Matthew Wilcox +M: Matthew Wilcox L: linux-scsi@vger.kernel.org S: Maintained F: drivers/scsi/sym53c8xx_2/ @@ -16137,6 +16137,17 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/vdso S: Maintained F: arch/x86/entry/vdso/ +XARRAY +M: Matthew Wilcox +L: linux-fsdevel@vger.kernel.org +S: Supported +F: Documentation/core-api/xarray.rst +F: lib/idr.c +F: lib/xarray.c +F: include/linux/idr.h +F: include/linux/xarray.h +F: tools/testing/radix-tree + XC2028/3028 TUNER DRIVER M: Mauro Carvalho Chehab L: linux-media@vger.kernel.org diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index f5f22ea9b97e..9505c317818d 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -2,7 +2,7 @@ * Linux/PA-RISC Project (http://www.parisc-linux.org/) * * System call entry code / Linux gateway page - * Copyright (c) Matthew Wilcox 1999 + * Copyright (c) Matthew Wilcox 1999 * Licensed under the GNU GPL. * thanks to Philipp Rumpf, Mike Shaver and various others * sorry about the wall, puffin.. diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index c4a726c10af5..6c99e846a8c9 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -716,9 +716,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) BUILD_BUG_ON(_PAGE_HPTEFLAGS & (0x1f << _PAGE_BIT_SWAP_TYPE)); \ BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY); \ } while (0) -/* - * on pte we don't need handle RADIX_TREE_EXCEPTIONAL_SHIFT; - */ + #define SWP_TYPE_BITS 5 #define __swp_type(x) (((x).val >> _PAGE_BIT_SWAP_TYPE) \ & ((1UL << SWP_TYPE_BITS) - 1)) diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h index 67421f74efcf..e77ed9761632 100644 --- a/arch/powerpc/include/asm/nohash/64/pgtable.h +++ b/arch/powerpc/include/asm/nohash/64/pgtable.h @@ -350,9 +350,7 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma, #define MAX_SWAPFILES_CHECK() do { \ BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS); \ } while (0) -/* - * on pte we don't need handle RADIX_TREE_EXCEPTIONAL_SHIFT; - */ + #define SWP_TYPE_BITS 5 #define __swp_type(x) (((x).val >> _PAGE_BIT_SWAP_TYPE) \ & ((1UL << SWP_TYPE_BITS) - 1)) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index fcc73a6ab503..316730b45f84 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -5996,7 +5996,8 @@ i915_gem_object_get_sg(struct drm_i915_gem_object *obj, count = __sg_page_count(sg); while (idx + count <= n) { - unsigned long exception, i; + void *entry; + unsigned long i; int ret; /* If we cannot allocate and insert this entry, or the @@ -6011,12 +6012,9 @@ i915_gem_object_get_sg(struct drm_i915_gem_object *obj, if (ret && ret != -EEXIST) goto scan; - exception = - RADIX_TREE_EXCEPTIONAL_ENTRY | - idx << RADIX_TREE_EXCEPTIONAL_SHIFT; + entry = xa_mk_value(idx); for (i = 1; i < count; i++) { - ret = radix_tree_insert(&iter->radix, idx + i, - (void *)exception); + ret = radix_tree_insert(&iter->radix, idx + i, entry); if (ret && ret != -EEXIST) goto scan; } @@ -6054,15 +6052,14 @@ lookup: GEM_BUG_ON(!sg); /* If this index is in the middle of multi-page sg entry, - * the radixtree will contain an exceptional entry that points + * the radix tree will contain a value entry that points * to the start of that range. We will return the pointer to * the base page and the offset of this page within the * sg entry's range. */ *offset = 0; - if (unlikely(radix_tree_exception(sg))) { - unsigned long base = - (unsigned long)sg >> RADIX_TREE_EXCEPTIONAL_SHIFT; + if (unlikely(xa_is_value(sg))) { + unsigned long base = xa_to_value(sg); sg = radix_tree_lookup(&iter->radix, base); GEM_BUG_ON(!sg); diff --git a/drivers/input/keyboard/hilkbd.c b/drivers/input/keyboard/hilkbd.c index 5c7afdec192c..f5c5ae8b6c06 100644 --- a/drivers/input/keyboard/hilkbd.c +++ b/drivers/input/keyboard/hilkbd.c @@ -2,7 +2,7 @@ * linux/drivers/hil/hilkbd.c * * Copyright (C) 1998 Philip Blundell - * Copyright (C) 1999 Matthew Wilcox + * Copyright (C) 1999 Matthew Wilcox * Copyright (C) 1999-2007 Helge Deller * * Very basic HP Human Interface Loop (HIL) driver. diff --git a/drivers/pci/hotplug/acpiphp.h b/drivers/pci/hotplug/acpiphp.h index cf3058404f41..a2094c07af6a 100644 --- a/drivers/pci/hotplug/acpiphp.h +++ b/drivers/pci/hotplug/acpiphp.h @@ -8,7 +8,7 @@ * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com) * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com) * Copyright (C) 2002,2003 NEC Corporation - * Copyright (C) 2003-2005 Matthew Wilcox (matthew.wilcox@hp.com) + * Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org) * Copyright (C) 2003-2005 Hewlett Packard * * All rights reserved. diff --git a/drivers/pci/hotplug/acpiphp_core.c b/drivers/pci/hotplug/acpiphp_core.c index c9e2bd40c038..853e04ad272c 100644 --- a/drivers/pci/hotplug/acpiphp_core.c +++ b/drivers/pci/hotplug/acpiphp_core.c @@ -8,7 +8,7 @@ * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com) * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com) * Copyright (C) 2002,2003 NEC Corporation - * Copyright (C) 2003-2005 Matthew Wilcox (matthew.wilcox@hp.com) + * Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org) * Copyright (C) 2003-2005 Hewlett Packard * * All rights reserved. @@ -40,7 +40,7 @@ bool acpiphp_disabled; static struct acpiphp_attention_info *attention_info; #define DRIVER_VERSION "0.5" -#define DRIVER_AUTHOR "Greg Kroah-Hartman , Takayoshi Kochi , Matthew Wilcox " +#define DRIVER_AUTHOR "Greg Kroah-Hartman , Takayoshi Kochi , Matthew Wilcox " #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver" MODULE_AUTHOR(DRIVER_AUTHOR); diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 12afa7fdf77e..e4c46637f32f 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -5,7 +5,7 @@ * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com) * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com) * Copyright (C) 2002,2003 NEC Corporation - * Copyright (C) 2003-2005 Matthew Wilcox (matthew.wilcox@hp.com) + * Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org) * Copyright (C) 2003-2005 Hewlett Packard * Copyright (C) 2005 Rajesh Shah (rajesh.shah@intel.com) * Copyright (C) 2005 Intel Corporation diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c index 595cf90af9bb..bdee9bd09f11 100644 --- a/drivers/staging/erofs/utils.c +++ b/drivers/staging/erofs/utils.c @@ -35,7 +35,6 @@ static atomic_long_t erofs_global_shrink_cnt; #ifdef CONFIG_EROFS_FS_ZIP -/* radix_tree and the future XArray both don't use tagptr_t yet */ struct erofs_workgroup *erofs_find_workgroup( struct super_block *sb, pgoff_t index, bool *tag) { @@ -47,9 +46,8 @@ repeat: rcu_read_lock(); grp = radix_tree_lookup(&sbi->workstn_tree, index); if (grp != NULL) { - *tag = radix_tree_exceptional_entry(grp); - grp = (void *)((unsigned long)grp & - ~RADIX_TREE_EXCEPTIONAL_ENTRY); + *tag = xa_pointer_tag(grp); + grp = xa_untag_pointer(grp); if (erofs_workgroup_get(grp, &oldcount)) { /* prefer to relax rcu read side */ @@ -83,9 +81,7 @@ int erofs_register_workgroup(struct super_block *sb, sbi = EROFS_SB(sb); erofs_workstn_lock(sbi); - if (tag) - grp = (void *)((unsigned long)grp | - 1UL << RADIX_TREE_EXCEPTIONAL_SHIFT); + grp = xa_tag_pointer(grp, tag); err = radix_tree_insert(&sbi->workstn_tree, grp->index, grp); @@ -131,9 +127,7 @@ repeat: for (i = 0; i < found; ++i) { int cnt; - struct erofs_workgroup *grp = (void *) - ((unsigned long)batch[i] & - ~RADIX_TREE_EXCEPTIONAL_ENTRY); + struct erofs_workgroup *grp = xa_untag_pointer(batch[i]); first_index = grp->index + 1; @@ -150,8 +144,8 @@ repeat: #endif continue; - if (radix_tree_delete(&sbi->workstn_tree, - grp->index) != grp) { + if (xa_untag_pointer(radix_tree_delete(&sbi->workstn_tree, + grp->index)) != grp) { #ifdef EROFS_FS_HAS_MANAGED_CACHE skip: erofs_workgroup_unfreeze(grp, 1); diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 8703ce68fe9d..2955a4ea2fa8 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -437,10 +437,8 @@ static noinline int add_ra_bio_pages(struct inode *inode, if (pg_index > end_index) break; - rcu_read_lock(); - page = radix_tree_lookup(&mapping->i_pages, pg_index); - rcu_read_unlock(); - if (page && !radix_tree_exceptional_entry(page)) { + page = xa_load(&mapping->i_pages, pg_index); + if (page && !xa_is_value(page)) { misses++; if (misses > 4) break; diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 6877a74c7469..d228f706ff3e 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3784,7 +3784,7 @@ int btree_write_cache_pages(struct address_space *mapping, pgoff_t index; pgoff_t end; /* Inclusive */ int scanned = 0; - int tag; + xa_mark_t tag; pagevec_init(&pvec); if (wbc->range_cyclic) { @@ -3909,7 +3909,7 @@ static int extent_write_cache_pages(struct address_space *mapping, pgoff_t done_index; int range_whole = 0; int scanned = 0; - int tag; + xa_mark_t tag; /* * We have to hold onto the inode so that ordered extents can do their @@ -5159,11 +5159,9 @@ void clear_extent_buffer_dirty(struct extent_buffer *eb) clear_page_dirty_for_io(page); xa_lock_irq(&page->mapping->i_pages); - if (!PageDirty(page)) { - radix_tree_tag_clear(&page->mapping->i_pages, - page_index(page), - PAGECACHE_TAG_DIRTY); - } + if (!PageDirty(page)) + __xa_clear_mark(&page->mapping->i_pages, + page_index(page), PAGECACHE_TAG_DIRTY); xa_unlock_irq(&page->mapping->i_pages); ClearPageError(page); unlock_page(page); diff --git a/fs/buffer.c b/fs/buffer.c index 109f55196866..d60d61e8ed7d 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -562,7 +562,7 @@ void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode) EXPORT_SYMBOL(mark_buffer_dirty_inode); /* - * Mark the page dirty, and set it dirty in the radix tree, and mark the inode + * Mark the page dirty, and set it dirty in the page cache, and mark the inode * dirty. * * If warn is true, then emit a warning if the page is not uptodate and has @@ -579,8 +579,8 @@ void __set_page_dirty(struct page *page, struct address_space *mapping, if (page->mapping) { /* Race with truncate? */ WARN_ON_ONCE(warn && !PageUptodate(page)); account_page_dirtied(page, mapping); - radix_tree_tag_set(&mapping->i_pages, - page_index(page), PAGECACHE_TAG_DIRTY); + __xa_set_mark(&mapping->i_pages, page_index(page), + PAGECACHE_TAG_DIRTY); } xa_unlock_irqrestore(&mapping->i_pages, flags); } @@ -1050,7 +1050,7 @@ __getblk_slow(struct block_device *bdev, sector_t block, * The relationship between dirty buffers and dirty pages: * * Whenever a page has any dirty buffers, the page's dirty bit is set, and - * the page is tagged dirty in its radix tree. + * the page is tagged dirty in the page cache. * * At all times, the dirtiness of the buffers represents the dirtiness of * subsections of the page. If the page has buffers, the page dirty bit is @@ -1073,9 +1073,9 @@ __getblk_slow(struct block_device *bdev, sector_t block, * mark_buffer_dirty - mark a buffer_head as needing writeout * @bh: the buffer_head to mark dirty * - * mark_buffer_dirty() will set the dirty bit against the buffer, then set its - * backing page dirty, then tag the page as dirty in its address_space's radix - * tree and then attach the address_space's inode to its superblock's dirty + * mark_buffer_dirty() will set the dirty bit against the buffer, then set + * its backing page dirty, then tag the page as dirty in the page cache + * and then attach the address_space's inode to its superblock's dirty * inode list. * * mark_buffer_dirty() is atomic. It takes bh->b_page->mapping->private_lock, diff --git a/fs/dax.c b/fs/dax.c index 0fb270f0a0ef..616e36ea6aaa 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -38,6 +38,17 @@ #define CREATE_TRACE_POINTS #include +static inline unsigned int pe_order(enum page_entry_size pe_size) +{ + if (pe_size == PE_SIZE_PTE) + return PAGE_SHIFT - PAGE_SHIFT; + if (pe_size == PE_SIZE_PMD) + return PMD_SHIFT - PAGE_SHIFT; + if (pe_size == PE_SIZE_PUD) + return PUD_SHIFT - PAGE_SHIFT; + return ~0; +} + /* We choose 4096 entries - same as per-zone page wait tables */ #define DAX_WAIT_TABLE_BITS 12 #define DAX_WAIT_TABLE_ENTRIES (1 << DAX_WAIT_TABLE_BITS) @@ -46,6 +57,9 @@ #define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1) #define PG_PMD_NR (PMD_SIZE >> PAGE_SHIFT) +/* The order of a PMD entry */ +#define PMD_ORDER (PMD_SHIFT - PAGE_SHIFT) + static wait_queue_head_t wait_table[DAX_WAIT_TABLE_ENTRIES]; static int __init init_dax_wait_table(void) @@ -59,63 +73,74 @@ static int __init init_dax_wait_table(void) fs_initcall(init_dax_wait_table); /* - * We use lowest available bit in exceptional entry for locking, one bit for - * the entry size (PMD) and two more to tell us if the entry is a zero page or - * an empty entry that is just used for locking. In total four special bits. + * DAX pagecache entries use XArray value entries so they can't be mistaken + * for pages. We use one bit for locking, one bit for the entry size (PMD) + * and two more to tell us if the entry is a zero page or an empty entry that + * is just used for locking. In total four special bits. * * If the PMD bit isn't set the entry has size PAGE_SIZE, and if the ZERO_PAGE * and EMPTY bits aren't set the entry is a normal DAX entry with a filesystem * block allocation. */ -#define RADIX_DAX_SHIFT (RADIX_TREE_EXCEPTIONAL_SHIFT + 4) -#define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT) -#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1)) -#define RADIX_DAX_ZERO_PAGE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2)) -#define RADIX_DAX_EMPTY (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3)) +#define DAX_SHIFT (4) +#define DAX_LOCKED (1UL << 0) +#define DAX_PMD (1UL << 1) +#define DAX_ZERO_PAGE (1UL << 2) +#define DAX_EMPTY (1UL << 3) -static unsigned long dax_radix_pfn(void *entry) +static unsigned long dax_to_pfn(void *entry) { - return (unsigned long)entry >> RADIX_DAX_SHIFT; + return xa_to_value(entry) >> DAX_SHIFT; } -static void *dax_radix_locked_entry(unsigned long pfn, unsigned long flags) +static void *dax_make_entry(pfn_t pfn, unsigned long flags) { - return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags | - (pfn << RADIX_DAX_SHIFT) | RADIX_DAX_ENTRY_LOCK); + return xa_mk_value(flags | (pfn_t_to_pfn(pfn) << DAX_SHIFT)); } -static unsigned int dax_radix_order(void *entry) +static void *dax_make_page_entry(struct page *page) { - if ((unsigned long)entry & RADIX_DAX_PMD) - return PMD_SHIFT - PAGE_SHIFT; + pfn_t pfn = page_to_pfn_t(page); + return dax_make_entry(pfn, PageHead(page) ? DAX_PMD : 0); +} + +static bool dax_is_locked(void *entry) +{ + return xa_to_value(entry) & DAX_LOCKED; +} + +static unsigned int dax_entry_order(void *entry) +{ + if (xa_to_value(entry) & DAX_PMD) + return PMD_ORDER; return 0; } static int dax_is_pmd_entry(void *entry) { - return (unsigned long)entry & RADIX_DAX_PMD; + return xa_to_value(entry) & DAX_PMD; } static int dax_is_pte_entry(void *entry) { - return !((unsigned long)entry & RADIX_DAX_PMD); + return !(xa_to_value(entry) & DAX_PMD); } static int dax_is_zero_entry(void *entry) { - return (unsigned long)entry & RADIX_DAX_ZERO_PAGE; + return xa_to_value(entry) & DAX_ZERO_PAGE; } static int dax_is_empty_entry(void *entry) { - return (unsigned long)entry & RADIX_DAX_EMPTY; + return xa_to_value(entry) & DAX_EMPTY; } /* - * DAX radix tree locking + * DAX page cache entry locking */ struct exceptional_entry_key { - struct address_space *mapping; + struct xarray *xa; pgoff_t entry_start; }; @@ -124,10 +149,11 @@ struct wait_exceptional_entry_queue { struct exceptional_entry_key key; }; -static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping, - pgoff_t index, void *entry, struct exceptional_entry_key *key) +static wait_queue_head_t *dax_entry_waitqueue(struct xa_state *xas, + void *entry, struct exceptional_entry_key *key) { unsigned long hash; + unsigned long index = xas->xa_index; /* * If 'entry' is a PMD, align the 'index' that we use for the wait @@ -136,22 +162,21 @@ static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping, */ if (dax_is_pmd_entry(entry)) index &= ~PG_PMD_COLOUR; - - key->mapping = mapping; + key->xa = xas->xa; key->entry_start = index; - hash = hash_long((unsigned long)mapping ^ index, DAX_WAIT_TABLE_BITS); + hash = hash_long((unsigned long)xas->xa ^ index, DAX_WAIT_TABLE_BITS); return wait_table + hash; } -static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mode, - int sync, void *keyp) +static int wake_exceptional_entry_func(wait_queue_entry_t *wait, + unsigned int mode, int sync, void *keyp) { struct exceptional_entry_key *key = keyp; struct wait_exceptional_entry_queue *ewait = container_of(wait, struct wait_exceptional_entry_queue, wait); - if (key->mapping != ewait->key.mapping || + if (key->xa != ewait->key.xa || key->entry_start != ewait->key.entry_start) return 0; return autoremove_wake_function(wait, mode, sync, NULL); @@ -162,13 +187,12 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mo * The important information it's conveying is whether the entry at * this index used to be a PMD entry. */ -static void dax_wake_mapping_entry_waiter(struct address_space *mapping, - pgoff_t index, void *entry, bool wake_all) +static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all) { struct exceptional_entry_key key; wait_queue_head_t *wq; - wq = dax_entry_waitqueue(mapping, index, entry, &key); + wq = dax_entry_waitqueue(xas, entry, &key); /* * Checking for locked entry and prepare_to_wait_exclusive() happens @@ -181,55 +205,16 @@ static void dax_wake_mapping_entry_waiter(struct address_space *mapping, } /* - * Check whether the given slot is locked. Must be called with the i_pages - * lock held. - */ -static inline int slot_locked(struct address_space *mapping, void **slot) -{ - unsigned long entry = (unsigned long) - radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock); - return entry & RADIX_DAX_ENTRY_LOCK; -} - -/* - * Mark the given slot as locked. Must be called with the i_pages lock held. - */ -static inline void *lock_slot(struct address_space *mapping, void **slot) -{ - unsigned long entry = (unsigned long) - radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock); - - entry |= RADIX_DAX_ENTRY_LOCK; - radix_tree_replace_slot(&mapping->i_pages, slot, (void *)entry); - return (void *)entry; -} - -/* - * Mark the given slot as unlocked. Must be called with the i_pages lock held. - */ -static inline void *unlock_slot(struct address_space *mapping, void **slot) -{ - unsigned long entry = (unsigned long) - radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock); - - entry &= ~(unsigned long)RADIX_DAX_ENTRY_LOCK; - radix_tree_replace_slot(&mapping->i_pages, slot, (void *)entry); - return (void *)entry; -} - -/* - * Lookup entry in radix tree, wait for it to become unlocked if it is - * exceptional entry and return it. The caller must call - * put_unlocked_mapping_entry() when he decided not to lock the entry or - * put_locked_mapping_entry() when he locked the entry and now wants to - * unlock it. + * Look up entry in page cache, wait for it to become unlocked if it + * is a DAX entry and return it. The caller must subsequently call + * put_unlocked_entry() if it did not lock the entry or dax_unlock_entry() + * if it did. * * Must be called with the i_pages lock held. */ -static void *__get_unlocked_mapping_entry(struct address_space *mapping, - pgoff_t index, void ***slotp, bool (*wait_fn)(void)) +static void *get_unlocked_entry(struct xa_state *xas) { - void *entry, **slot; + void *entry; struct wait_exceptional_entry_queue ewait; wait_queue_head_t *wq; @@ -237,80 +222,54 @@ static void *__get_unlocked_mapping_entry(struct address_space *mapping, ewait.wait.func = wake_exceptional_entry_func; for (;;) { - bool revalidate; - - entry = __radix_tree_lookup(&mapping->i_pages, index, NULL, - &slot); - if (!entry || - WARN_ON_ONCE(!radix_tree_exceptional_entry(entry)) || - !slot_locked(mapping, slot)) { - if (slotp) - *slotp = slot; + entry = xas_load(xas); + if (!entry || xa_is_internal(entry) || + WARN_ON_ONCE(!xa_is_value(entry)) || + !dax_is_locked(entry)) return entry; - } - wq = dax_entry_waitqueue(mapping, index, entry, &ewait.key); + wq = dax_entry_waitqueue(xas, entry, &ewait.key); prepare_to_wait_exclusive(wq, &ewait.wait, TASK_UNINTERRUPTIBLE); - xa_unlock_irq(&mapping->i_pages); - revalidate = wait_fn(); + xas_unlock_irq(xas); + xas_reset(xas); + schedule(); finish_wait(wq, &ewait.wait); - xa_lock_irq(&mapping->i_pages); - if (revalidate) - return ERR_PTR(-EAGAIN); + xas_lock_irq(xas); } } -static bool entry_wait(void) +static void put_unlocked_entry(struct xa_state *xas, void *entry) { - schedule(); - /* - * Never return an ERR_PTR() from - * __get_unlocked_mapping_entry(), just keep looping. - */ - return false; -} - -static void *get_unlocked_mapping_entry(struct address_space *mapping, - pgoff_t index, void ***slotp) -{ - return __get_unlocked_mapping_entry(mapping, index, slotp, entry_wait); -} - -static void unlock_mapping_entry(struct address_space *mapping, pgoff_t index) -{ - void *entry, **slot; - - xa_lock_irq(&mapping->i_pages); - entry = __radix_tree_lookup(&mapping->i_pages, index, NULL, &slot); - if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry) || - !slot_locked(mapping, slot))) { - xa_unlock_irq(&mapping->i_pages); - return; - } - unlock_slot(mapping, slot); - xa_unlock_irq(&mapping->i_pages); - dax_wake_mapping_entry_waiter(mapping, index, entry, false); -} - -static void put_locked_mapping_entry(struct address_space *mapping, - pgoff_t index) -{ - unlock_mapping_entry(mapping, index); + /* If we were the only waiter woken, wake the next one */ + if (entry) + dax_wake_entry(xas, entry, false); } /* - * Called when we are done with radix tree entry we looked up via - * get_unlocked_mapping_entry() and which we didn't lock in the end. + * We used the xa_state to get the entry, but then we locked the entry and + * dropped the xa_lock, so we know the xa_state is stale and must be reset + * before use. */ -static void put_unlocked_mapping_entry(struct address_space *mapping, - pgoff_t index, void *entry) +static void dax_unlock_entry(struct xa_state *xas, void *entry) { - if (!entry) - return; + void *old; - /* We have to wake up next waiter for the radix tree entry lock */ - dax_wake_mapping_entry_waiter(mapping, index, entry, false); + xas_reset(xas); + xas_lock_irq(xas); + old = xas_store(xas, entry); + xas_unlock_irq(xas); + BUG_ON(!dax_is_locked(old)); + dax_wake_entry(xas, entry, false); +} + +/* + * Return: The entry stored at this location before it was locked. + */ +static void *dax_lock_entry(struct xa_state *xas, void *entry) +{ + unsigned long v = xa_to_value(entry); + return xas_store(xas, xa_mk_value(v | DAX_LOCKED)); } static unsigned long dax_entry_size(void *entry) @@ -325,9 +284,9 @@ static unsigned long dax_entry_size(void *entry) return PAGE_SIZE; } -static unsigned long dax_radix_end_pfn(void *entry) +static unsigned long dax_end_pfn(void *entry) { - return dax_radix_pfn(entry) + dax_entry_size(entry) / PAGE_SIZE; + return dax_to_pfn(entry) + dax_entry_size(entry) / PAGE_SIZE; } /* @@ -335,8 +294,8 @@ static unsigned long dax_radix_end_pfn(void *entry) * 'empty' and 'zero' entries. */ #define for_each_mapped_pfn(entry, pfn) \ - for (pfn = dax_radix_pfn(entry); \ - pfn < dax_radix_end_pfn(entry); pfn++) + for (pfn = dax_to_pfn(entry); \ + pfn < dax_end_pfn(entry); pfn++) /* * TODO: for reflink+dax we need a way to associate a single page with @@ -393,33 +352,16 @@ static struct page *dax_busy_page(void *entry) return NULL; } -static bool entry_wait_revalidate(void) -{ - rcu_read_unlock(); - schedule(); - rcu_read_lock(); - - /* - * Tell __get_unlocked_mapping_entry() to take a break, we need - * to revalidate page->mapping after dropping locks - */ - return true; -} - bool dax_lock_mapping_entry(struct page *page) { - pgoff_t index; - struct inode *inode; - bool did_lock = false; - void *entry = NULL, **slot; - struct address_space *mapping; + XA_STATE(xas, NULL, 0); + void *entry; - rcu_read_lock(); for (;;) { - mapping = READ_ONCE(page->mapping); + struct address_space *mapping = READ_ONCE(page->mapping); if (!dax_mapping(mapping)) - break; + return false; /* * In the device-dax case there's no need to lock, a @@ -428,98 +370,94 @@ bool dax_lock_mapping_entry(struct page *page) * otherwise we would not have a valid pfn_to_page() * translation. */ - inode = mapping->host; - if (S_ISCHR(inode->i_mode)) { - did_lock = true; - break; - } + if (S_ISCHR(mapping->host->i_mode)) + return true; - xa_lock_irq(&mapping->i_pages); + xas.xa = &mapping->i_pages; + xas_lock_irq(&xas); if (mapping != page->mapping) { - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); continue; } - index = page->index; - - entry = __get_unlocked_mapping_entry(mapping, index, &slot, - entry_wait_revalidate); - if (!entry) { - xa_unlock_irq(&mapping->i_pages); - break; - } else if (IS_ERR(entry)) { - xa_unlock_irq(&mapping->i_pages); - WARN_ON_ONCE(PTR_ERR(entry) != -EAGAIN); - continue; + xas_set(&xas, page->index); + entry = xas_load(&xas); + if (dax_is_locked(entry)) { + entry = get_unlocked_entry(&xas); + /* Did the page move while we slept? */ + if (dax_to_pfn(entry) != page_to_pfn(page)) { + xas_unlock_irq(&xas); + continue; + } } - lock_slot(mapping, slot); - did_lock = true; - xa_unlock_irq(&mapping->i_pages); - break; + dax_lock_entry(&xas, entry); + xas_unlock_irq(&xas); + return true; } - rcu_read_unlock(); - - return did_lock; } void dax_unlock_mapping_entry(struct page *page) { struct address_space *mapping = page->mapping; - struct inode *inode = mapping->host; + XA_STATE(xas, &mapping->i_pages, page->index); - if (S_ISCHR(inode->i_mode)) + if (S_ISCHR(mapping->host->i_mode)) return; - unlock_mapping_entry(mapping, page->index); + dax_unlock_entry(&xas, dax_make_page_entry(page)); } /* - * Find radix tree entry at given index. If it points to an exceptional entry, - * return it with the radix tree entry locked. If the radix tree doesn't - * contain given index, create an empty exceptional entry for the index and - * return with it locked. + * Find page cache entry at given index. If it is a DAX entry, return it + * with the entry locked. If the page cache doesn't contain an entry at + * that index, add a locked empty entry. * - * When requesting an entry with size RADIX_DAX_PMD, grab_mapping_entry() will - * either return that locked entry or will return an error. This error will - * happen if there are any 4k entries within the 2MiB range that we are - * requesting. + * When requesting an entry with size DAX_PMD, grab_mapping_entry() will + * either return that locked entry or will return VM_FAULT_FALLBACK. + * This will happen if there are any PTE entries within the PMD range + * that we are requesting. * - * We always favor 4k entries over 2MiB entries. There isn't a flow where we - * evict 4k entries in order to 'upgrade' them to a 2MiB entry. A 2MiB - * insertion will fail if it finds any 4k entries already in the tree, and a - * 4k insertion will cause an existing 2MiB entry to be unmapped and - * downgraded to 4k entries. This happens for both 2MiB huge zero pages as - * well as 2MiB empty entries. + * We always favor PTE entries over PMD entries. There isn't a flow where we + * evict PTE entries in order to 'upgrade' them to a PMD entry. A PMD + * insertion will fail if it finds any PTE entries already in the tree, and a + * PTE insertion will cause an existing PMD entry to be unmapped and + * downgraded to PTE entries. This happens for both PMD zero pages as + * well as PMD empty entries. * - * The exception to this downgrade path is for 2MiB DAX PMD entries that have - * real storage backing them. We will leave these real 2MiB DAX entries in - * the tree, and PTE writes will simply dirty the entire 2MiB DAX entry. + * The exception to this downgrade path is for PMD entries that have + * real storage backing them. We will leave these real PMD entries in + * the tree, and PTE writes will simply dirty the entire PMD entry. * * Note: Unlike filemap_fault() we don't honor FAULT_FLAG_RETRY flags. For * persistent memory the benefit is doubtful. We can add that later if we can * show it helps. + * + * On error, this function does not return an ERR_PTR. Instead it returns + * a VM_FAULT code, encoded as an xarray internal entry. The ERR_PTR values + * overlap with xarray value entries. */ -static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, - unsigned long size_flag) +static void *grab_mapping_entry(struct xa_state *xas, + struct address_space *mapping, unsigned long size_flag) { - bool pmd_downgrade = false; /* splitting 2MiB entry into 4k entries? */ - void *entry, **slot; + unsigned long index = xas->xa_index; + bool pmd_downgrade = false; /* splitting PMD entry into PTE entries? */ + void *entry; -restart: - xa_lock_irq(&mapping->i_pages); - entry = get_unlocked_mapping_entry(mapping, index, &slot); - - if (WARN_ON_ONCE(entry && !radix_tree_exceptional_entry(entry))) { - entry = ERR_PTR(-EIO); - goto out_unlock; - } +retry: + xas_lock_irq(xas); + entry = get_unlocked_entry(xas); + if (xa_is_internal(entry)) + goto fallback; if (entry) { - if (size_flag & RADIX_DAX_PMD) { + if (WARN_ON_ONCE(!xa_is_value(entry))) { + xas_set_err(xas, EIO); + goto out_unlock; + } + + if (size_flag & DAX_PMD) { if (dax_is_pte_entry(entry)) { - put_unlocked_mapping_entry(mapping, index, - entry); - entry = ERR_PTR(-EEXIST); - goto out_unlock; + put_unlocked_entry(xas, entry); + goto fallback; } } else { /* trying to grab a PTE entry */ if (dax_is_pmd_entry(entry) && @@ -530,87 +468,57 @@ restart: } } - /* No entry for given index? Make sure radix tree is big enough. */ - if (!entry || pmd_downgrade) { - int err; + if (pmd_downgrade) { + /* + * Make sure 'entry' remains valid while we drop + * the i_pages lock. + */ + dax_lock_entry(xas, entry); - if (pmd_downgrade) { - /* - * Make sure 'entry' remains valid while we drop - * the i_pages lock. - */ - entry = lock_slot(mapping, slot); - } - - xa_unlock_irq(&mapping->i_pages); /* * Besides huge zero pages the only other thing that gets * downgraded are empty entries which don't need to be * unmapped. */ - if (pmd_downgrade && dax_is_zero_entry(entry)) - unmap_mapping_pages(mapping, index & ~PG_PMD_COLOUR, - PG_PMD_NR, false); - - err = radix_tree_preload( - mapping_gfp_mask(mapping) & ~__GFP_HIGHMEM); - if (err) { - if (pmd_downgrade) - put_locked_mapping_entry(mapping, index); - return ERR_PTR(err); - } - xa_lock_irq(&mapping->i_pages); - - if (!entry) { - /* - * We needed to drop the i_pages lock while calling - * radix_tree_preload() and we didn't have an entry to - * lock. See if another thread inserted an entry at - * our index during this time. - */ - entry = __radix_tree_lookup(&mapping->i_pages, index, - NULL, &slot); - if (entry) { - radix_tree_preload_end(); - xa_unlock_irq(&mapping->i_pages); - goto restart; - } + if (dax_is_zero_entry(entry)) { + xas_unlock_irq(xas); + unmap_mapping_pages(mapping, + xas->xa_index & ~PG_PMD_COLOUR, + PG_PMD_NR, false); + xas_reset(xas); + xas_lock_irq(xas); } - if (pmd_downgrade) { - dax_disassociate_entry(entry, mapping, false); - radix_tree_delete(&mapping->i_pages, index); - mapping->nrexceptional--; - dax_wake_mapping_entry_waiter(mapping, index, entry, - true); - } - - entry = dax_radix_locked_entry(0, size_flag | RADIX_DAX_EMPTY); - - err = __radix_tree_insert(&mapping->i_pages, index, - dax_radix_order(entry), entry); - radix_tree_preload_end(); - if (err) { - xa_unlock_irq(&mapping->i_pages); - /* - * Our insertion of a DAX entry failed, most likely - * because we were inserting a PMD entry and it - * collided with a PTE sized entry at a different - * index in the PMD range. We haven't inserted - * anything into the radix tree and have no waiters to - * wake. - */ - return ERR_PTR(err); - } - /* Good, we have inserted empty locked entry into the tree. */ - mapping->nrexceptional++; - xa_unlock_irq(&mapping->i_pages); - return entry; + dax_disassociate_entry(entry, mapping, false); + xas_store(xas, NULL); /* undo the PMD join */ + dax_wake_entry(xas, entry, true); + mapping->nrexceptional--; + entry = NULL; + xas_set(xas, index); } - entry = lock_slot(mapping, slot); - out_unlock: - xa_unlock_irq(&mapping->i_pages); + + if (entry) { + dax_lock_entry(xas, entry); + } else { + entry = dax_make_entry(pfn_to_pfn_t(0), size_flag | DAX_EMPTY); + dax_lock_entry(xas, entry); + if (xas_error(xas)) + goto out_unlock; + mapping->nrexceptional++; + } + +out_unlock: + xas_unlock_irq(xas); + if (xas_nomem(xas, mapping_gfp_mask(mapping) & ~__GFP_HIGHMEM)) + goto retry; + if (xas->xa_node == XA_ERROR(-ENOMEM)) + return xa_mk_internal(VM_FAULT_OOM); + if (xas_error(xas)) + return xa_mk_internal(VM_FAULT_SIGBUS); return entry; +fallback: + xas_unlock_irq(xas); + return xa_mk_internal(VM_FAULT_FALLBACK); } /** @@ -630,11 +538,10 @@ restart: */ struct page *dax_layout_busy_page(struct address_space *mapping) { - pgoff_t indices[PAGEVEC_SIZE]; + XA_STATE(xas, &mapping->i_pages, 0); + void *entry; + unsigned int scanned = 0; struct page *page = NULL; - struct pagevec pvec; - pgoff_t index, end; - unsigned i; /* * In the 'limited' case get_user_pages() for dax is disabled. @@ -645,13 +552,9 @@ struct page *dax_layout_busy_page(struct address_space *mapping) if (!dax_mapping(mapping) || !mapping_mapped(mapping)) return NULL; - pagevec_init(&pvec); - index = 0; - end = -1; - /* * If we race get_user_pages_fast() here either we'll see the - * elevated page count in the pagevec_lookup and wait, or + * elevated page count in the iteration and wait, or * get_user_pages_fast() will see that the page it took a reference * against is no longer mapped in the page tables and bail to the * get_user_pages() slow path. The slow path is protected by @@ -663,94 +566,68 @@ struct page *dax_layout_busy_page(struct address_space *mapping) */ unmap_mapping_range(mapping, 0, 0, 1); - while (index < end && pagevec_lookup_entries(&pvec, mapping, index, - min(end - index, (pgoff_t)PAGEVEC_SIZE), - indices)) { - pgoff_t nr_pages = 1; - - for (i = 0; i < pagevec_count(&pvec); i++) { - struct page *pvec_ent = pvec.pages[i]; - void *entry; - - index = indices[i]; - if (index >= end) - break; - - if (WARN_ON_ONCE( - !radix_tree_exceptional_entry(pvec_ent))) - continue; - - xa_lock_irq(&mapping->i_pages); - entry = get_unlocked_mapping_entry(mapping, index, NULL); - if (entry) { - page = dax_busy_page(entry); - /* - * Account for multi-order entries at - * the end of the pagevec. - */ - if (i + 1 >= pagevec_count(&pvec)) - nr_pages = 1UL << dax_radix_order(entry); - } - put_unlocked_mapping_entry(mapping, index, entry); - xa_unlock_irq(&mapping->i_pages); - if (page) - break; - } - - /* - * We don't expect normal struct page entries to exist in our - * tree, but we keep these pagevec calls so that this code is - * consistent with the common pattern for handling pagevecs - * throughout the kernel. - */ - pagevec_remove_exceptionals(&pvec); - pagevec_release(&pvec); - index += nr_pages; - + xas_lock_irq(&xas); + xas_for_each(&xas, entry, ULONG_MAX) { + if (WARN_ON_ONCE(!xa_is_value(entry))) + continue; + if (unlikely(dax_is_locked(entry))) + entry = get_unlocked_entry(&xas); + if (entry) + page = dax_busy_page(entry); + put_unlocked_entry(&xas, entry); if (page) break; + if (++scanned % XA_CHECK_SCHED) + continue; + + xas_pause(&xas); + xas_unlock_irq(&xas); + cond_resched(); + xas_lock_irq(&xas); } + xas_unlock_irq(&xas); return page; } EXPORT_SYMBOL_GPL(dax_layout_busy_page); -static int __dax_invalidate_mapping_entry(struct address_space *mapping, +static int __dax_invalidate_entry(struct address_space *mapping, pgoff_t index, bool trunc) { + XA_STATE(xas, &mapping->i_pages, index); int ret = 0; void *entry; - struct radix_tree_root *pages = &mapping->i_pages; - xa_lock_irq(pages); - entry = get_unlocked_mapping_entry(mapping, index, NULL); - if (!entry || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry))) + xas_lock_irq(&xas); + entry = get_unlocked_entry(&xas); + if (!entry || WARN_ON_ONCE(!xa_is_value(entry))) goto out; if (!trunc && - (radix_tree_tag_get(pages, index, PAGECACHE_TAG_DIRTY) || - radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE))) + (xas_get_mark(&xas, PAGECACHE_TAG_DIRTY) || + xas_get_mark(&xas, PAGECACHE_TAG_TOWRITE))) goto out; dax_disassociate_entry(entry, mapping, trunc); - radix_tree_delete(pages, index); + xas_store(&xas, NULL); mapping->nrexceptional--; ret = 1; out: - put_unlocked_mapping_entry(mapping, index, entry); - xa_unlock_irq(pages); + put_unlocked_entry(&xas, entry); + xas_unlock_irq(&xas); return ret; } + /* - * Delete exceptional DAX entry at @index from @mapping. Wait for radix tree - * entry to get unlocked before deleting it. + * Delete DAX entry at @index from @mapping. Wait for it + * to be unlocked before deleting it. */ int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index) { - int ret = __dax_invalidate_mapping_entry(mapping, index, true); + int ret = __dax_invalidate_entry(mapping, index, true); /* * This gets called from truncate / punch_hole path. As such, the caller * must hold locks protecting against concurrent modifications of the - * radix tree (usually fs-private i_mmap_sem for writing). Since the - * caller has seen exceptional entry for this index, we better find it + * page cache (usually fs-private i_mmap_sem for writing). Since the + * caller has seen a DAX entry for this index, we better find it * at that index as well... */ WARN_ON_ONCE(!ret); @@ -758,12 +635,12 @@ int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index) } /* - * Invalidate exceptional DAX entry if it is clean. + * Invalidate DAX entry if it is clean. */ int dax_invalidate_mapping_entry_sync(struct address_space *mapping, pgoff_t index) { - return __dax_invalidate_mapping_entry(mapping, index, false); + return __dax_invalidate_entry(mapping, index, false); } static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, @@ -799,30 +676,27 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, * already in the tree, we will skip the insertion and just dirty the PMD as * appropriate. */ -static void *dax_insert_mapping_entry(struct address_space *mapping, - struct vm_fault *vmf, - void *entry, pfn_t pfn_t, - unsigned long flags, bool dirty) +static void *dax_insert_entry(struct xa_state *xas, + struct address_space *mapping, struct vm_fault *vmf, + void *entry, pfn_t pfn, unsigned long flags, bool dirty) { - struct radix_tree_root *pages = &mapping->i_pages; - unsigned long pfn = pfn_t_to_pfn(pfn_t); - pgoff_t index = vmf->pgoff; - void *new_entry; + void *new_entry = dax_make_entry(pfn, flags); if (dirty) __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); - if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) { + if (dax_is_zero_entry(entry) && !(flags & DAX_ZERO_PAGE)) { + unsigned long index = xas->xa_index; /* we are replacing a zero page with block mapping */ if (dax_is_pmd_entry(entry)) unmap_mapping_pages(mapping, index & ~PG_PMD_COLOUR, - PG_PMD_NR, false); + PG_PMD_NR, false); else /* pte entry */ - unmap_mapping_pages(mapping, vmf->pgoff, 1, false); + unmap_mapping_pages(mapping, index, 1, false); } - xa_lock_irq(pages); - new_entry = dax_radix_locked_entry(pfn, flags); + xas_reset(xas); + xas_lock_irq(xas); if (dax_entry_size(entry) != dax_entry_size(new_entry)) { dax_disassociate_entry(entry, mapping, false); dax_associate_entry(new_entry, mapping, vmf->vma, vmf->address); @@ -830,33 +704,30 @@ static void *dax_insert_mapping_entry(struct address_space *mapping, if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) { /* - * Only swap our new entry into the radix tree if the current + * Only swap our new entry into the page cache if the current * entry is a zero page or an empty entry. If a normal PTE or - * PMD entry is already in the tree, we leave it alone. This + * PMD entry is already in the cache, we leave it alone. This * means that if we are trying to insert a PTE and the * existing entry is a PMD, we will just leave the PMD in the * tree and dirty it if necessary. */ - struct radix_tree_node *node; - void **slot; - void *ret; - - ret = __radix_tree_lookup(pages, index, &node, &slot); - WARN_ON_ONCE(ret != entry); - __radix_tree_replace(pages, node, slot, - new_entry, NULL); + void *old = dax_lock_entry(xas, new_entry); + WARN_ON_ONCE(old != xa_mk_value(xa_to_value(entry) | + DAX_LOCKED)); entry = new_entry; + } else { + xas_load(xas); /* Walk the xa_state */ } if (dirty) - radix_tree_tag_set(pages, index, PAGECACHE_TAG_DIRTY); + xas_set_mark(xas, PAGECACHE_TAG_DIRTY); - xa_unlock_irq(pages); + xas_unlock_irq(xas); return entry; } -static inline unsigned long -pgoff_address(pgoff_t pgoff, struct vm_area_struct *vma) +static inline +unsigned long pgoff_address(pgoff_t pgoff, struct vm_area_struct *vma) { unsigned long address; @@ -866,8 +737,8 @@ pgoff_address(pgoff_t pgoff, struct vm_area_struct *vma) } /* Walk all mappings of a given index of a file and writeprotect them */ -static void dax_mapping_entry_mkclean(struct address_space *mapping, - pgoff_t index, unsigned long pfn) +static void dax_entry_mkclean(struct address_space *mapping, pgoff_t index, + unsigned long pfn) { struct vm_area_struct *vma; pte_t pte, *ptep = NULL; @@ -937,11 +808,9 @@ unlock_pte: i_mmap_unlock_read(mapping); } -static int dax_writeback_one(struct dax_device *dax_dev, - struct address_space *mapping, pgoff_t index, void *entry) +static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev, + struct address_space *mapping, void *entry) { - struct radix_tree_root *pages = &mapping->i_pages; - void *entry2, **slot; unsigned long pfn; long ret = 0; size_t size; @@ -950,32 +819,38 @@ static int dax_writeback_one(struct dax_device *dax_dev, * A page got tagged dirty in DAX mapping? Something is seriously * wrong. */ - if (WARN_ON(!radix_tree_exceptional_entry(entry))) + if (WARN_ON(!xa_is_value(entry))) return -EIO; - xa_lock_irq(pages); - entry2 = get_unlocked_mapping_entry(mapping, index, &slot); - /* Entry got punched out / reallocated? */ - if (!entry2 || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry2))) - goto put_unlocked; - /* - * Entry got reallocated elsewhere? No need to writeback. We have to - * compare pfns as we must not bail out due to difference in lockbit - * or entry type. - */ - if (dax_radix_pfn(entry2) != dax_radix_pfn(entry)) - goto put_unlocked; - if (WARN_ON_ONCE(dax_is_empty_entry(entry) || - dax_is_zero_entry(entry))) { - ret = -EIO; - goto put_unlocked; + if (unlikely(dax_is_locked(entry))) { + void *old_entry = entry; + + entry = get_unlocked_entry(xas); + + /* Entry got punched out / reallocated? */ + if (!entry || WARN_ON_ONCE(!xa_is_value(entry))) + goto put_unlocked; + /* + * Entry got reallocated elsewhere? No need to writeback. + * We have to compare pfns as we must not bail out due to + * difference in lockbit or entry type. + */ + if (dax_to_pfn(old_entry) != dax_to_pfn(entry)) + goto put_unlocked; + if (WARN_ON_ONCE(dax_is_empty_entry(entry) || + dax_is_zero_entry(entry))) { + ret = -EIO; + goto put_unlocked; + } + + /* Another fsync thread may have already done this entry */ + if (!xas_get_mark(xas, PAGECACHE_TAG_TOWRITE)) + goto put_unlocked; } - /* Another fsync thread may have already written back this entry */ - if (!radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE)) - goto put_unlocked; /* Lock the entry to serialize with page faults */ - entry = lock_slot(mapping, slot); + dax_lock_entry(xas, entry); + /* * We can clear the tag now but we have to be careful so that concurrent * dax_writeback_one() calls for the same index cannot finish before we @@ -983,8 +858,8 @@ static int dax_writeback_one(struct dax_device *dax_dev, * at the entry only under the i_pages lock and once they do that * they will see the entry locked and wait for it to unlock. */ - radix_tree_tag_clear(pages, index, PAGECACHE_TAG_TOWRITE); - xa_unlock_irq(pages); + xas_clear_mark(xas, PAGECACHE_TAG_TOWRITE); + xas_unlock_irq(xas); /* * Even if dax_writeback_mapping_range() was given a wbc->range_start @@ -993,10 +868,10 @@ static int dax_writeback_one(struct dax_device *dax_dev, * This allows us to flush for PMD_SIZE and not have to worry about * partial PMD writebacks. */ - pfn = dax_radix_pfn(entry); - size = PAGE_SIZE << dax_radix_order(entry); + pfn = dax_to_pfn(entry); + size = PAGE_SIZE << dax_entry_order(entry); - dax_mapping_entry_mkclean(mapping, index, pfn); + dax_entry_mkclean(mapping, xas->xa_index, pfn); dax_flush(dax_dev, page_address(pfn_to_page(pfn)), size); /* * After we have flushed the cache, we can clear the dirty tag. There @@ -1004,16 +879,18 @@ static int dax_writeback_one(struct dax_device *dax_dev, * the pfn mappings are writeprotected and fault waits for mapping * entry lock. */ - xa_lock_irq(pages); - radix_tree_tag_clear(pages, index, PAGECACHE_TAG_DIRTY); - xa_unlock_irq(pages); - trace_dax_writeback_one(mapping->host, index, size >> PAGE_SHIFT); - put_locked_mapping_entry(mapping, index); + xas_reset(xas); + xas_lock_irq(xas); + xas_store(xas, entry); + xas_clear_mark(xas, PAGECACHE_TAG_DIRTY); + dax_wake_entry(xas, entry, false); + + trace_dax_writeback_one(mapping->host, xas->xa_index, + size >> PAGE_SHIFT); return ret; put_unlocked: - put_unlocked_mapping_entry(mapping, index, entry2); - xa_unlock_irq(pages); + put_unlocked_entry(xas, entry); return ret; } @@ -1025,13 +902,13 @@ static int dax_writeback_one(struct dax_device *dax_dev, int dax_writeback_mapping_range(struct address_space *mapping, struct block_device *bdev, struct writeback_control *wbc) { + XA_STATE(xas, &mapping->i_pages, wbc->range_start >> PAGE_SHIFT); struct inode *inode = mapping->host; - pgoff_t start_index, end_index; - pgoff_t indices[PAGEVEC_SIZE]; + pgoff_t end_index = wbc->range_end >> PAGE_SHIFT; struct dax_device *dax_dev; - struct pagevec pvec; - bool done = false; - int i, ret = 0; + void *entry; + int ret = 0; + unsigned int scanned = 0; if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT)) return -EIO; @@ -1043,41 +920,29 @@ int dax_writeback_mapping_range(struct address_space *mapping, if (!dax_dev) return -EIO; - start_index = wbc->range_start >> PAGE_SHIFT; - end_index = wbc->range_end >> PAGE_SHIFT; + trace_dax_writeback_range(inode, xas.xa_index, end_index); - trace_dax_writeback_range(inode, start_index, end_index); + tag_pages_for_writeback(mapping, xas.xa_index, end_index); - tag_pages_for_writeback(mapping, start_index, end_index); - - pagevec_init(&pvec); - while (!done) { - pvec.nr = find_get_entries_tag(mapping, start_index, - PAGECACHE_TAG_TOWRITE, PAGEVEC_SIZE, - pvec.pages, indices); - - if (pvec.nr == 0) + xas_lock_irq(&xas); + xas_for_each_marked(&xas, entry, end_index, PAGECACHE_TAG_TOWRITE) { + ret = dax_writeback_one(&xas, dax_dev, mapping, entry); + if (ret < 0) { + mapping_set_error(mapping, ret); break; - - for (i = 0; i < pvec.nr; i++) { - if (indices[i] > end_index) { - done = true; - break; - } - - ret = dax_writeback_one(dax_dev, mapping, indices[i], - pvec.pages[i]); - if (ret < 0) { - mapping_set_error(mapping, ret); - goto out; - } } - start_index = indices[pvec.nr - 1] + 1; + if (++scanned % XA_CHECK_SCHED) + continue; + + xas_pause(&xas); + xas_unlock_irq(&xas); + cond_resched(); + xas_lock_irq(&xas); } -out: + xas_unlock_irq(&xas); put_dax(dax_dev); - trace_dax_writeback_range_done(inode, start_index, end_index); - return (ret < 0 ? ret : 0); + trace_dax_writeback_range_done(inode, xas.xa_index, end_index); + return ret; } EXPORT_SYMBOL_GPL(dax_writeback_mapping_range); @@ -1125,16 +990,18 @@ out: * If this page is ever written to we will re-fault and change the mapping to * point to real DAX storage instead. */ -static vm_fault_t dax_load_hole(struct address_space *mapping, void *entry, - struct vm_fault *vmf) +static vm_fault_t dax_load_hole(struct xa_state *xas, + struct address_space *mapping, void **entry, + struct vm_fault *vmf) { struct inode *inode = mapping->host; unsigned long vaddr = vmf->address; pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr)); vm_fault_t ret; - dax_insert_mapping_entry(mapping, vmf, entry, pfn, RADIX_DAX_ZERO_PAGE, - false); + *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, + DAX_ZERO_PAGE, false); + ret = vmf_insert_mixed(vmf->vma, vaddr, pfn); trace_dax_load_hole(inode, vmf, ret); return ret; @@ -1342,6 +1209,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, { struct vm_area_struct *vma = vmf->vma; struct address_space *mapping = vma->vm_file->f_mapping; + XA_STATE(xas, &mapping->i_pages, vmf->pgoff); struct inode *inode = mapping->host; unsigned long vaddr = vmf->address; loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; @@ -1368,9 +1236,9 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, if (write && !vmf->cow_page) flags |= IOMAP_WRITE; - entry = grab_mapping_entry(mapping, vmf->pgoff, 0); - if (IS_ERR(entry)) { - ret = dax_fault_return(PTR_ERR(entry)); + entry = grab_mapping_entry(&xas, mapping, 0); + if (xa_is_internal(entry)) { + ret = xa_to_internal(entry); goto out; } @@ -1443,7 +1311,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, if (error < 0) goto error_finish_iomap; - entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn, + entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, 0, write && !sync); /* @@ -1471,7 +1339,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, case IOMAP_UNWRITTEN: case IOMAP_HOLE: if (!write) { - ret = dax_load_hole(mapping, entry, vmf); + ret = dax_load_hole(&xas, mapping, &entry, vmf); goto finish_iomap; } /*FALLTHRU*/ @@ -1498,21 +1366,20 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, ops->iomap_end(inode, pos, PAGE_SIZE, copied, flags, &iomap); } unlock_entry: - put_locked_mapping_entry(mapping, vmf->pgoff); + dax_unlock_entry(&xas, entry); out: trace_dax_pte_fault_done(inode, vmf, ret); return ret | major; } #ifdef CONFIG_FS_DAX_PMD -static vm_fault_t dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap, - void *entry) +static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, + struct iomap *iomap, void **entry) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; unsigned long pmd_addr = vmf->address & PMD_MASK; struct inode *inode = mapping->host; struct page *zero_page; - void *ret = NULL; spinlock_t *ptl; pmd_t pmd_entry; pfn_t pfn; @@ -1523,8 +1390,8 @@ static vm_fault_t dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap, goto fallback; pfn = page_to_pfn_t(zero_page); - ret = dax_insert_mapping_entry(mapping, vmf, entry, pfn, - RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false); + *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, + DAX_PMD | DAX_ZERO_PAGE, false); ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); if (!pmd_none(*(vmf->pmd))) { @@ -1536,11 +1403,11 @@ static vm_fault_t dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap, pmd_entry = pmd_mkhuge(pmd_entry); set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); spin_unlock(ptl); - trace_dax_pmd_load_hole(inode, vmf, zero_page, ret); + trace_dax_pmd_load_hole(inode, vmf, zero_page, *entry); return VM_FAULT_NOPAGE; fallback: - trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, ret); + trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); return VM_FAULT_FALLBACK; } @@ -1549,6 +1416,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, { struct vm_area_struct *vma = vmf->vma; struct address_space *mapping = vma->vm_file->f_mapping; + XA_STATE_ORDER(xas, &mapping->i_pages, vmf->pgoff, PMD_ORDER); unsigned long pmd_addr = vmf->address & PMD_MASK; bool write = vmf->flags & FAULT_FLAG_WRITE; bool sync; @@ -1556,7 +1424,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, struct inode *inode = mapping->host; vm_fault_t result = VM_FAULT_FALLBACK; struct iomap iomap = { 0 }; - pgoff_t max_pgoff, pgoff; + pgoff_t max_pgoff; void *entry; loff_t pos; int error; @@ -1567,7 +1435,6 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, * supposed to hold locks serializing us with truncate / punch hole so * this is a reliable test. */ - pgoff = linear_page_index(vma, pmd_addr); max_pgoff = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); trace_dax_pmd_fault(inode, vmf, max_pgoff, 0); @@ -1576,7 +1443,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, * Make sure that the faulting address's PMD offset (color) matches * the PMD offset from the start of the file. This is necessary so * that a PMD range in the page table overlaps exactly with a PMD - * range in the radix tree. + * range in the page cache. */ if ((vmf->pgoff & PG_PMD_COLOUR) != ((vmf->address >> PAGE_SHIFT) & PG_PMD_COLOUR)) @@ -1592,24 +1459,26 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, if ((pmd_addr + PMD_SIZE) > vma->vm_end) goto fallback; - if (pgoff >= max_pgoff) { + if (xas.xa_index >= max_pgoff) { result = VM_FAULT_SIGBUS; goto out; } /* If the PMD would extend beyond the file size */ - if ((pgoff | PG_PMD_COLOUR) >= max_pgoff) + if ((xas.xa_index | PG_PMD_COLOUR) >= max_pgoff) goto fallback; /* - * grab_mapping_entry() will make sure we get a 2MiB empty entry, a - * 2MiB zero page entry or a DAX PMD. If it can't (because a 4k page - * is already in the tree, for instance), it will return -EEXIST and - * we just fall back to 4k entries. + * grab_mapping_entry() will make sure we get an empty PMD entry, + * a zero PMD entry or a DAX PMD. If it can't (because a PTE + * entry is already in the array, for instance), it will return + * VM_FAULT_FALLBACK. */ - entry = grab_mapping_entry(mapping, pgoff, RADIX_DAX_PMD); - if (IS_ERR(entry)) + entry = grab_mapping_entry(&xas, mapping, DAX_PMD); + if (xa_is_internal(entry)) { + result = xa_to_internal(entry); goto fallback; + } /* * It is possible, particularly with mixed reads & writes to private @@ -1628,7 +1497,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, * setting up a mapping, so really we're using iomap_begin() as a way * to look up our filesystem block. */ - pos = (loff_t)pgoff << PAGE_SHIFT; + pos = (loff_t)xas.xa_index << PAGE_SHIFT; error = ops->iomap_begin(inode, pos, PMD_SIZE, iomap_flags, &iomap); if (error) goto unlock_entry; @@ -1644,8 +1513,8 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, if (error < 0) goto finish_iomap; - entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn, - RADIX_DAX_PMD, write && !sync); + entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, + DAX_PMD, write && !sync); /* * If we are doing synchronous page fault and inode needs fsync, @@ -1669,7 +1538,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, case IOMAP_HOLE: if (WARN_ON_ONCE(write)) break; - result = dax_pmd_load_hole(vmf, &iomap, entry); + result = dax_pmd_load_hole(&xas, vmf, &iomap, &entry); break; default: WARN_ON_ONCE(1); @@ -1692,7 +1561,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, &iomap); } unlock_entry: - put_locked_mapping_entry(mapping, pgoff); + dax_unlock_entry(&xas, entry); fallback: if (result == VM_FAULT_FALLBACK) { split_huge_pmd(vma, vmf->pmd, vmf->address); @@ -1737,54 +1606,49 @@ vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, } EXPORT_SYMBOL_GPL(dax_iomap_fault); -/** +/* * dax_insert_pfn_mkwrite - insert PTE or PMD entry into page tables * @vmf: The description of the fault - * @pe_size: Size of entry to be inserted * @pfn: PFN to insert + * @order: Order of entry to insert. * - * This function inserts writeable PTE or PMD entry into page tables for mmaped - * DAX file. It takes care of marking corresponding radix tree entry as dirty - * as well. + * This function inserts a writeable PTE or PMD entry into the page tables + * for an mmaped DAX file. It also marks the page cache entry as dirty. */ -static vm_fault_t dax_insert_pfn_mkwrite(struct vm_fault *vmf, - enum page_entry_size pe_size, - pfn_t pfn) +static vm_fault_t +dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order) { struct address_space *mapping = vmf->vma->vm_file->f_mapping; - void *entry, **slot; - pgoff_t index = vmf->pgoff; + XA_STATE_ORDER(xas, &mapping->i_pages, vmf->pgoff, order); + void *entry; vm_fault_t ret; - xa_lock_irq(&mapping->i_pages); - entry = get_unlocked_mapping_entry(mapping, index, &slot); + xas_lock_irq(&xas); + entry = get_unlocked_entry(&xas); /* Did we race with someone splitting entry or so? */ if (!entry || - (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) || - (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) { - put_unlocked_mapping_entry(mapping, index, entry); - xa_unlock_irq(&mapping->i_pages); + (order == 0 && !dax_is_pte_entry(entry)) || + (order == PMD_ORDER && (xa_is_internal(entry) || + !dax_is_pmd_entry(entry)))) { + put_unlocked_entry(&xas, entry); + xas_unlock_irq(&xas); trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf, VM_FAULT_NOPAGE); return VM_FAULT_NOPAGE; } - radix_tree_tag_set(&mapping->i_pages, index, PAGECACHE_TAG_DIRTY); - entry = lock_slot(mapping, slot); - xa_unlock_irq(&mapping->i_pages); - switch (pe_size) { - case PE_SIZE_PTE: + xas_set_mark(&xas, PAGECACHE_TAG_DIRTY); + dax_lock_entry(&xas, entry); + xas_unlock_irq(&xas); + if (order == 0) ret = vmf_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn); - break; #ifdef CONFIG_FS_DAX_PMD - case PE_SIZE_PMD: + else if (order == PMD_ORDER) ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, pfn, true); - break; #endif - default: + else ret = VM_FAULT_FALLBACK; - } - put_locked_mapping_entry(mapping, index); + dax_unlock_entry(&xas, entry); trace_dax_insert_pfn_mkwrite(mapping->host, vmf, ret); return ret; } @@ -1804,17 +1668,12 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf, { int err; loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT; - size_t len = 0; + unsigned int order = pe_order(pe_size); + size_t len = PAGE_SIZE << order; - if (pe_size == PE_SIZE_PTE) - len = PAGE_SIZE; - else if (pe_size == PE_SIZE_PMD) - len = PMD_SIZE; - else - WARN_ON_ONCE(1); err = vfs_fsync_range(vmf->vma->vm_file, start, start + len - 1, 1); if (err) return VM_FAULT_SIGBUS; - return dax_insert_pfn_mkwrite(vmf, pe_size, pfn); + return dax_insert_pfn_mkwrite(vmf, pfn, order); } EXPORT_SYMBOL_GPL(dax_finish_sync_fault); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c3d9a42c561e..05f01fbd9c7f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2643,7 +2643,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) long left = mpd->wbc->nr_to_write; pgoff_t index = mpd->first_page; pgoff_t end = mpd->last_page; - int tag; + xa_mark_t tag; int i, err = 0; int blkbits = mpd->inode->i_blkbits; ext4_lblk_t lblk; diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 106f116466bf..b293cb3e27a2 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2071,7 +2071,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping, pgoff_t done_index; int cycled; int range_whole = 0; - int tag; + xa_mark_t tag; int nwritten = 0; pagevec_init(&pvec); @@ -2787,13 +2787,13 @@ const struct address_space_operations f2fs_dblock_aops = { #endif }; -void f2fs_clear_radix_tree_dirty_tag(struct page *page) +void f2fs_clear_page_cache_dirty_tag(struct page *page) { struct address_space *mapping = page_mapping(page); unsigned long flags; xa_lock_irqsave(&mapping->i_pages, flags); - radix_tree_tag_clear(&mapping->i_pages, page_index(page), + __xa_clear_mark(&mapping->i_pages, page_index(page), PAGECACHE_TAG_DIRTY); xa_unlock_irqrestore(&mapping->i_pages, flags); } diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 2ef84b4590ea..bacc667950b6 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -726,7 +726,7 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page, if (bit_pos == NR_DENTRY_IN_BLOCK && !f2fs_truncate_hole(dir, page->index, page->index + 1)) { - f2fs_clear_radix_tree_dirty_tag(page); + f2fs_clear_page_cache_dirty_tag(page); clear_page_dirty_for_io(page); ClearPagePrivate(page); ClearPageUptodate(page); diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 56204a8f8a12..1e031971a466 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3108,7 +3108,7 @@ int f2fs_migrate_page(struct address_space *mapping, struct page *newpage, struct page *page, enum migrate_mode mode); #endif bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len); -void f2fs_clear_radix_tree_dirty_tag(struct page *page); +void f2fs_clear_page_cache_dirty_tag(struct page *page); /* * gc.c diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index cb31a719b048..7b0cff7e6051 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -243,7 +243,7 @@ int f2fs_write_inline_data(struct inode *inode, struct page *page) kunmap_atomic(src_addr); set_page_dirty(dn.inode_page); - f2fs_clear_radix_tree_dirty_tag(page); + f2fs_clear_page_cache_dirty_tag(page); set_inode_flag(inode, FI_APPEND_WRITE); set_inode_flag(inode, FI_DATA_EXIST); diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 2b34206486d8..d338740d0fda 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -101,7 +101,7 @@ bool f2fs_available_free_memory(struct f2fs_sb_info *sbi, int type) static void clear_node_page_dirty(struct page *page) { if (PageDirty(page)) { - f2fs_clear_radix_tree_dirty_tag(page); + f2fs_clear_page_cache_dirty_tag(page); clear_page_dirty_for_io(page); dec_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES); } @@ -1306,9 +1306,7 @@ void f2fs_ra_node_page(struct f2fs_sb_info *sbi, nid_t nid) if (f2fs_check_nid_range(sbi, nid)) return; - rcu_read_lock(); - apage = radix_tree_lookup(&NODE_MAPPING(sbi)->i_pages, nid); - rcu_read_unlock(); + apage = xa_load(&NODE_MAPPING(sbi)->i_pages, nid); if (apage) return; diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 471d863958bc..b40168fcc94a 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -339,9 +339,9 @@ static void inode_switch_wbs_work_fn(struct work_struct *work) struct address_space *mapping = inode->i_mapping; struct bdi_writeback *old_wb = inode->i_wb; struct bdi_writeback *new_wb = isw->new_wb; - struct radix_tree_iter iter; + XA_STATE(xas, &mapping->i_pages, 0); + struct page *page; bool switched = false; - void **slot; /* * By the time control reaches here, RCU grace period has passed @@ -375,25 +375,18 @@ static void inode_switch_wbs_work_fn(struct work_struct *work) * to possibly dirty pages while PAGECACHE_TAG_WRITEBACK points to * pages actually under writeback. */ - radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, 0, - PAGECACHE_TAG_DIRTY) { - struct page *page = radix_tree_deref_slot_protected(slot, - &mapping->i_pages.xa_lock); - if (likely(page) && PageDirty(page)) { + xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_DIRTY) { + if (PageDirty(page)) { dec_wb_stat(old_wb, WB_RECLAIMABLE); inc_wb_stat(new_wb, WB_RECLAIMABLE); } } - radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, 0, - PAGECACHE_TAG_WRITEBACK) { - struct page *page = radix_tree_deref_slot_protected(slot, - &mapping->i_pages.xa_lock); - if (likely(page)) { - WARN_ON_ONCE(!PageWriteback(page)); - dec_wb_stat(old_wb, WB_WRITEBACK); - inc_wb_stat(new_wb, WB_WRITEBACK); - } + xas_set(&xas, 0); + xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_WRITEBACK) { + WARN_ON_ONCE(!PageWriteback(page)); + dec_wb_stat(old_wb, WB_WRITEBACK); + inc_wb_stat(new_wb, WB_WRITEBACK); } wb_get(new_wb); diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 31e8270d0b26..8afbb35559b9 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -366,7 +366,7 @@ static int gfs2_write_cache_jdata(struct address_space *mapping, pgoff_t done_index; int cycled; int range_whole = 0; - int tag; + xa_mark_t tag; pagevec_init(&pvec); if (wbc->range_cyclic) { diff --git a/fs/inode.c b/fs/inode.c index 42f6d25f32a5..9b808986d440 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -349,7 +349,7 @@ EXPORT_SYMBOL(inc_nlink); static void __address_space_init_once(struct address_space *mapping) { - INIT_RADIX_TREE(&mapping->i_pages, GFP_ATOMIC | __GFP_ACCOUNT); + xa_init_flags(&mapping->i_pages, XA_FLAGS_LOCK_IRQ); init_rwsem(&mapping->i_mmap_rwsem); INIT_LIST_HEAD(&mapping->private_list); spin_lock_init(&mapping->private_lock); diff --git a/fs/isofs/dir.c b/fs/isofs/dir.c index 947ce22f5b3c..f0fe641893a5 100644 --- a/fs/isofs/dir.c +++ b/fs/isofs/dir.c @@ -46,7 +46,7 @@ int isofs_name_translate(struct iso_directory_record *de, char *new, struct inod return i; } -/* Acorn extensions written by Matthew Wilcox 1998 */ +/* Acorn extensions written by Matthew Wilcox 1998 */ int get_acorn_filename(struct iso_directory_record *de, char *retname, struct inode *inode) { diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index 06cb0c1d9aee..d3781cd983f6 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -896,7 +896,7 @@ static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx) end = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); if (end != inode->i_mapping->nrpages) { rcu_read_lock(); - end = page_cache_next_hole(mapping, idx + 1, ULONG_MAX); + end = page_cache_next_miss(mapping, idx + 1, ULONG_MAX); rcu_read_unlock(); } diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index ebb24a314f43..de99db518571 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -168,24 +168,18 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc, ctxt->newbh = NULL; if (inode->i_blkbits == PAGE_SHIFT) { - lock_page(obh->b_page); - /* - * We cannot call radix_tree_preload for the kernels older - * than 2.6.23, because it is not exported for modules. - */ + struct page *opage = obh->b_page; + lock_page(opage); retry: - err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); - if (err) - goto failed_unlock; /* BUG_ON(oldkey != obh->b_page->index); */ - if (unlikely(oldkey != obh->b_page->index)) - NILFS_PAGE_BUG(obh->b_page, + if (unlikely(oldkey != opage->index)) + NILFS_PAGE_BUG(opage, "invalid oldkey %lld (newkey=%lld)", (unsigned long long)oldkey, (unsigned long long)newkey); xa_lock_irq(&btnc->i_pages); - err = radix_tree_insert(&btnc->i_pages, newkey, obh->b_page); + err = __xa_insert(&btnc->i_pages, newkey, opage, GFP_NOFS); xa_unlock_irq(&btnc->i_pages); /* * Note: page->index will not change to newkey until @@ -193,7 +187,6 @@ retry: * To protect the page in intermediate state, the page lock * is held. */ - radix_tree_preload_end(); if (!err) return 0; else if (err != -EEXIST) @@ -203,7 +196,7 @@ retry: if (!err) goto retry; /* fallback to copy mode */ - unlock_page(obh->b_page); + unlock_page(opage); } nbh = nilfs_btnode_create_block(btnc, newkey); @@ -243,9 +236,8 @@ void nilfs_btnode_commit_change_key(struct address_space *btnc, mark_buffer_dirty(obh); xa_lock_irq(&btnc->i_pages); - radix_tree_delete(&btnc->i_pages, oldkey); - radix_tree_tag_set(&btnc->i_pages, newkey, - PAGECACHE_TAG_DIRTY); + __xa_erase(&btnc->i_pages, oldkey); + __xa_set_mark(&btnc->i_pages, newkey, PAGECACHE_TAG_DIRTY); xa_unlock_irq(&btnc->i_pages); opage->index = obh->b_blocknr = newkey; @@ -275,7 +267,7 @@ void nilfs_btnode_abort_change_key(struct address_space *btnc, if (nbh == NULL) { /* blocksize == pagesize */ xa_lock_irq(&btnc->i_pages); - radix_tree_delete(&btnc->i_pages, newkey); + __xa_erase(&btnc->i_pages, newkey); xa_unlock_irq(&btnc->i_pages); unlock_page(ctxt->bh->b_page); } else diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 329a056b73b1..d7fc8d369d89 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -289,7 +289,7 @@ repeat: * @dmap: destination page cache * @smap: source page cache * - * No pages must no be added to the cache during this process. + * No pages must be added to the cache during this process. * This must be ensured by the caller. */ void nilfs_copy_back_pages(struct address_space *dmap, @@ -298,7 +298,6 @@ void nilfs_copy_back_pages(struct address_space *dmap, struct pagevec pvec; unsigned int i, n; pgoff_t index = 0; - int err; pagevec_init(&pvec); repeat: @@ -313,35 +312,34 @@ repeat: lock_page(page); dpage = find_lock_page(dmap, offset); if (dpage) { - /* override existing page on the destination cache */ + /* overwrite existing page in the destination cache */ WARN_ON(PageDirty(dpage)); nilfs_copy_page(dpage, page, 0); unlock_page(dpage); put_page(dpage); + /* Do we not need to remove page from smap here? */ } else { - struct page *page2; + struct page *p; /* move the page to the destination cache */ xa_lock_irq(&smap->i_pages); - page2 = radix_tree_delete(&smap->i_pages, offset); - WARN_ON(page2 != page); - + p = __xa_erase(&smap->i_pages, offset); + WARN_ON(page != p); smap->nrpages--; xa_unlock_irq(&smap->i_pages); xa_lock_irq(&dmap->i_pages); - err = radix_tree_insert(&dmap->i_pages, offset, page); - if (unlikely(err < 0)) { - WARN_ON(err == -EEXIST); + p = __xa_store(&dmap->i_pages, offset, page, GFP_NOFS); + if (unlikely(p)) { + /* Probably -ENOMEM */ page->mapping = NULL; - put_page(page); /* for cache */ + put_page(page); } else { page->mapping = dmap; dmap->nrpages++; if (PageDirty(page)) - radix_tree_tag_set(&dmap->i_pages, - offset, - PAGECACHE_TAG_DIRTY); + __xa_set_mark(&dmap->i_pages, offset, + PAGECACHE_TAG_DIRTY); } xa_unlock_irq(&dmap->i_pages); } @@ -467,8 +465,7 @@ int __nilfs_clear_page_dirty(struct page *page) if (mapping) { xa_lock_irq(&mapping->i_pages); if (test_bit(PG_dirty, &page->flags)) { - radix_tree_tag_clear(&mapping->i_pages, - page_index(page), + __xa_clear_mark(&mapping->i_pages, page_index(page), PAGECACHE_TAG_DIRTY); xa_unlock_irq(&mapping->i_pages); return clear_page_dirty_for_io(page); diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index a027473561c6..47c3764c469b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -521,7 +521,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr, if (!page) return; - if (radix_tree_exceptional_entry(page)) + if (xa_is_value(page)) mss->swap += PAGE_SIZE; else put_page(page); diff --git a/include/linux/fs.h b/include/linux/fs.h index 897eae8faee1..771341470bce 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -403,24 +403,40 @@ int pagecache_write_end(struct file *, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata); +/** + * struct address_space - Contents of a cacheable, mappable object. + * @host: Owner, either the inode or the block_device. + * @i_pages: Cached pages. + * @gfp_mask: Memory allocation flags to use for allocating pages. + * @i_mmap_writable: Number of VM_SHARED mappings. + * @i_mmap: Tree of private and shared mappings. + * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable. + * @nrpages: Number of page entries, protected by the i_pages lock. + * @nrexceptional: Shadow or DAX entries, protected by the i_pages lock. + * @writeback_index: Writeback starts here. + * @a_ops: Methods. + * @flags: Error bits and flags (AS_*). + * @wb_err: The most recent error which has occurred. + * @private_lock: For use by the owner of the address_space. + * @private_list: For use by the owner of the address_space. + * @private_data: For use by the owner of the address_space. + */ struct address_space { - struct inode *host; /* owner: inode, block_device */ - struct radix_tree_root i_pages; /* cached pages */ - atomic_t i_mmap_writable;/* count VM_SHARED mappings */ - struct rb_root_cached i_mmap; /* tree of private and shared mappings */ - struct rw_semaphore i_mmap_rwsem; /* protect tree, count, list */ - /* Protected by the i_pages lock */ - unsigned long nrpages; /* number of total pages */ - /* number of shadow or DAX exceptional entries */ + struct inode *host; + struct xarray i_pages; + gfp_t gfp_mask; + atomic_t i_mmap_writable; + struct rb_root_cached i_mmap; + struct rw_semaphore i_mmap_rwsem; + unsigned long nrpages; unsigned long nrexceptional; - pgoff_t writeback_index;/* writeback starts here */ - const struct address_space_operations *a_ops; /* methods */ - unsigned long flags; /* error bits */ - spinlock_t private_lock; /* for use by the address_space */ - gfp_t gfp_mask; /* implicit gfp mask for allocations */ - struct list_head private_list; /* for use by the address_space */ - void *private_data; /* ditto */ + pgoff_t writeback_index; + const struct address_space_operations *a_ops; + unsigned long flags; errseq_t wb_err; + spinlock_t private_lock; + struct list_head private_list; + void *private_data; } __attribute__((aligned(sizeof(long)))) __randomize_layout; /* * On most architectures that alignment is already the case; but @@ -467,15 +483,18 @@ struct block_device { struct mutex bd_fsfreeze_mutex; } __randomize_layout; -/* - * Radix-tree tags, for tagging dirty and writeback pages within the pagecache - * radix trees - */ -#define PAGECACHE_TAG_DIRTY 0 -#define PAGECACHE_TAG_WRITEBACK 1 -#define PAGECACHE_TAG_TOWRITE 2 +/* XArray tags, for tagging dirty and writeback pages in the pagecache. */ +#define PAGECACHE_TAG_DIRTY XA_MARK_0 +#define PAGECACHE_TAG_WRITEBACK XA_MARK_1 +#define PAGECACHE_TAG_TOWRITE XA_MARK_2 -int mapping_tagged(struct address_space *mapping, int tag); +/* + * Returns true if any of the pages in the mapping are marked with the tag. + */ +static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag) +{ + return xa_marked(&mapping->i_pages, tag); +} static inline void i_mmap_lock_write(struct address_space *mapping) { diff --git a/include/linux/idr.h b/include/linux/idr.h index 3ec8628ce17f..60daf34b625d 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -214,8 +214,7 @@ static inline void idr_preload_end(void) ++id, (entry) = idr_get_next((idr), &(id))) /* - * IDA - IDR based id allocator, use when translation from id to - * pointer isn't necessary. + * IDA - ID Allocator, use when translation from id to pointer isn't necessary. */ #define IDA_CHUNK_SIZE 128 /* 128 bytes per chunk */ #define IDA_BITMAP_LONGS (IDA_CHUNK_SIZE / sizeof(long)) @@ -225,14 +224,14 @@ struct ida_bitmap { unsigned long bitmap[IDA_BITMAP_LONGS]; }; -DECLARE_PER_CPU(struct ida_bitmap *, ida_bitmap); - struct ida { - struct radix_tree_root ida_rt; + struct xarray xa; }; +#define IDA_INIT_FLAGS (XA_FLAGS_LOCK_IRQ | XA_FLAGS_ALLOC) + #define IDA_INIT(name) { \ - .ida_rt = RADIX_TREE_INIT(name, IDR_RT_MARKER | GFP_NOWAIT), \ + .xa = XARRAY_INIT(name, IDA_INIT_FLAGS) \ } #define DEFINE_IDA(name) struct ida name = IDA_INIT(name) @@ -292,7 +291,7 @@ static inline int ida_alloc_max(struct ida *ida, unsigned int max, gfp_t gfp) static inline void ida_init(struct ida *ida) { - INIT_RADIX_TREE(&ida->ida_rt, IDR_RT_MARKER | GFP_NOWAIT); + xa_init_flags(&ida->xa, IDA_INIT_FLAGS); } #define ida_simple_get(ida, start, end, gfp) \ @@ -301,9 +300,6 @@ static inline void ida_init(struct ida *ida) static inline bool ida_is_empty(const struct ida *ida) { - return radix_tree_empty(&ida->ida_rt); + return xa_empty(&ida->xa); } - -/* in lib/radix-tree.c */ -int ida_pre_get(struct ida *ida, gfp_t gfp_mask); #endif /* __IDR_H__ */ diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index b1bd2186e6d2..226f96f0dee0 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -241,9 +241,9 @@ static inline gfp_t readahead_gfp_mask(struct address_space *x) typedef int filler_t(void *, struct page *); -pgoff_t page_cache_next_hole(struct address_space *mapping, +pgoff_t page_cache_next_miss(struct address_space *mapping, pgoff_t index, unsigned long max_scan); -pgoff_t page_cache_prev_hole(struct address_space *mapping, +pgoff_t page_cache_prev_miss(struct address_space *mapping, pgoff_t index, unsigned long max_scan); #define FGP_ACCESSED 0x00000001 @@ -363,17 +363,17 @@ static inline unsigned find_get_pages(struct address_space *mapping, unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start, unsigned int nr_pages, struct page **pages); unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index, - pgoff_t end, int tag, unsigned int nr_pages, + pgoff_t end, xa_mark_t tag, unsigned int nr_pages, struct page **pages); static inline unsigned find_get_pages_tag(struct address_space *mapping, - pgoff_t *index, int tag, unsigned int nr_pages, + pgoff_t *index, xa_mark_t tag, unsigned int nr_pages, struct page **pages) { return find_get_pages_range_tag(mapping, index, (pgoff_t)-1, tag, nr_pages, pages); } unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start, - int tag, unsigned int nr_entries, + xa_mark_t tag, unsigned int nr_entries, struct page **entries, pgoff_t *indices); struct page *grab_cache_page_write_begin(struct address_space *mapping, diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h index 6dc456ac6136..081d934eda64 100644 --- a/include/linux/pagevec.h +++ b/include/linux/pagevec.h @@ -9,6 +9,8 @@ #ifndef _LINUX_PAGEVEC_H #define _LINUX_PAGEVEC_H +#include + /* 15 pointers + header align the pagevec structure to a power of two */ #define PAGEVEC_SIZE 15 @@ -40,12 +42,12 @@ static inline unsigned pagevec_lookup(struct pagevec *pvec, unsigned pagevec_lookup_range_tag(struct pagevec *pvec, struct address_space *mapping, pgoff_t *index, pgoff_t end, - int tag); + xa_mark_t tag); unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec, struct address_space *mapping, pgoff_t *index, pgoff_t end, - int tag, unsigned max_pages); + xa_mark_t tag, unsigned max_pages); static inline unsigned pagevec_lookup_tag(struct pagevec *pvec, - struct address_space *mapping, pgoff_t *index, int tag) + struct address_space *mapping, pgoff_t *index, xa_mark_t tag) { return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag); } diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 34149e8b5f73..06c4c7a6c09c 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -28,34 +28,30 @@ #include #include #include +#include + +/* Keep unconverted code working */ +#define radix_tree_root xarray +#define radix_tree_node xa_node /* * The bottom two bits of the slot determine how the remaining bits in the * slot are interpreted: * * 00 - data pointer - * 01 - internal entry - * 10 - exceptional entry - * 11 - this bit combination is currently unused/reserved + * 10 - internal entry + * x1 - value entry * * The internal entry may be a pointer to the next level in the tree, a * sibling entry, or an indicator that the entry in this slot has been moved * to another location in the tree and the lookup should be restarted. While * NULL fits the 'data pointer' pattern, it means that there is no entry in * the tree for this index (no matter what level of the tree it is found at). - * This means that you cannot store NULL in the tree as a value for the index. + * This means that storing a NULL entry in the tree is the same as deleting + * the entry from the tree. */ #define RADIX_TREE_ENTRY_MASK 3UL -#define RADIX_TREE_INTERNAL_NODE 1UL - -/* - * Most users of the radix tree store pointers but shmem/tmpfs stores swap - * entries in the same tree. They are marked as exceptional entries to - * distinguish them from pointers to struct page. - * EXCEPTIONAL_ENTRY tests the bit, EXCEPTIONAL_SHIFT shifts content past it. - */ -#define RADIX_TREE_EXCEPTIONAL_ENTRY 2 -#define RADIX_TREE_EXCEPTIONAL_SHIFT 2 +#define RADIX_TREE_INTERNAL_NODE 2UL static inline bool radix_tree_is_internal_node(void *ptr) { @@ -65,75 +61,32 @@ static inline bool radix_tree_is_internal_node(void *ptr) /*** radix-tree API starts here ***/ -#define RADIX_TREE_MAX_TAGS 3 - -#ifndef RADIX_TREE_MAP_SHIFT -#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) -#endif - +#define RADIX_TREE_MAP_SHIFT XA_CHUNK_SHIFT #define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT) #define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1) -#define RADIX_TREE_TAG_LONGS \ - ((RADIX_TREE_MAP_SIZE + BITS_PER_LONG - 1) / BITS_PER_LONG) +#define RADIX_TREE_MAX_TAGS XA_MAX_MARKS +#define RADIX_TREE_TAG_LONGS XA_MARK_LONGS #define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long)) #define RADIX_TREE_MAX_PATH (DIV_ROUND_UP(RADIX_TREE_INDEX_BITS, \ RADIX_TREE_MAP_SHIFT)) -/* - * @count is the count of every non-NULL element in the ->slots array - * whether that is an exceptional entry, a retry entry, a user pointer, - * a sibling entry or a pointer to the next level of the tree. - * @exceptional is the count of every element in ->slots which is - * either radix_tree_exceptional_entry() or is a sibling entry for an - * exceptional entry. - */ -struct radix_tree_node { - unsigned char shift; /* Bits remaining in each slot */ - unsigned char offset; /* Slot offset in parent */ - unsigned char count; /* Total entry count */ - unsigned char exceptional; /* Exceptional entry count */ - struct radix_tree_node *parent; /* Used when ascending tree */ - struct radix_tree_root *root; /* The tree we belong to */ - union { - struct list_head private_list; /* For tree user */ - struct rcu_head rcu_head; /* Used when freeing node */ - }; - void __rcu *slots[RADIX_TREE_MAP_SIZE]; - unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS]; -}; - -/* The IDR tag is stored in the low bits of the GFP flags */ +/* The IDR tag is stored in the low bits of xa_flags */ #define ROOT_IS_IDR ((__force gfp_t)4) -/* The top bits of gfp_mask are used to store the root tags */ +/* The top bits of xa_flags are used to store the root tags */ #define ROOT_TAG_SHIFT (__GFP_BITS_SHIFT) -struct radix_tree_root { - spinlock_t xa_lock; - gfp_t gfp_mask; - struct radix_tree_node __rcu *rnode; -}; - -#define RADIX_TREE_INIT(name, mask) { \ - .xa_lock = __SPIN_LOCK_UNLOCKED(name.xa_lock), \ - .gfp_mask = (mask), \ - .rnode = NULL, \ -} +#define RADIX_TREE_INIT(name, mask) XARRAY_INIT(name, mask) #define RADIX_TREE(name, mask) \ struct radix_tree_root name = RADIX_TREE_INIT(name, mask) -#define INIT_RADIX_TREE(root, mask) \ -do { \ - spin_lock_init(&(root)->xa_lock); \ - (root)->gfp_mask = (mask); \ - (root)->rnode = NULL; \ -} while (0) +#define INIT_RADIX_TREE(root, mask) xa_init_flags(root, mask) static inline bool radix_tree_empty(const struct radix_tree_root *root) { - return root->rnode == NULL; + return root->xa_head == NULL; } /** @@ -143,7 +96,6 @@ static inline bool radix_tree_empty(const struct radix_tree_root *root) * @next_index: one beyond the last index for this chunk * @tags: bit-mask for tag-iterating * @node: node that contains current slot - * @shift: shift for the node that holds our slots * * This radix tree iterator works in terms of "chunks" of slots. A chunk is a * subinterval of slots contained within one radix tree leaf node. It is @@ -157,20 +109,8 @@ struct radix_tree_iter { unsigned long next_index; unsigned long tags; struct radix_tree_node *node; -#ifdef CONFIG_RADIX_TREE_MULTIORDER - unsigned int shift; -#endif }; -static inline unsigned int iter_shift(const struct radix_tree_iter *iter) -{ -#ifdef CONFIG_RADIX_TREE_MULTIORDER - return iter->shift; -#else - return 0; -#endif -} - /** * Radix-tree synchronization * @@ -194,12 +134,11 @@ static inline unsigned int iter_shift(const struct radix_tree_iter *iter) * radix_tree_lookup_slot * radix_tree_tag_get * radix_tree_gang_lookup - * radix_tree_gang_lookup_slot * radix_tree_gang_lookup_tag * radix_tree_gang_lookup_tag_slot * radix_tree_tagged * - * The first 8 functions are able to be called locklessly, using RCU. The + * The first 7 functions are able to be called locklessly, using RCU. The * caller must ensure calls to these functions are made within rcu_read_lock() * regions. Other readers (lock-free or otherwise) and modifications may be * running concurrently. @@ -268,17 +207,6 @@ static inline int radix_tree_deref_retry(void *arg) return unlikely(radix_tree_is_internal_node(arg)); } -/** - * radix_tree_exceptional_entry - radix_tree_deref_slot gave exceptional entry? - * @arg: value returned by radix_tree_deref_slot - * Returns: 0 if well-aligned pointer, non-0 if exceptional entry. - */ -static inline int radix_tree_exceptional_entry(void *arg) -{ - /* Not unlikely because radix_tree_exception often tested first */ - return (unsigned long)arg & RADIX_TREE_EXCEPTIONAL_ENTRY; -} - /** * radix_tree_exception - radix_tree_deref_slot returned either exception? * @arg: value returned by radix_tree_deref_slot @@ -289,47 +217,28 @@ static inline int radix_tree_exception(void *arg) return unlikely((unsigned long)arg & RADIX_TREE_ENTRY_MASK); } -int __radix_tree_create(struct radix_tree_root *, unsigned long index, - unsigned order, struct radix_tree_node **nodep, - void __rcu ***slotp); -int __radix_tree_insert(struct radix_tree_root *, unsigned long index, - unsigned order, void *); -static inline int radix_tree_insert(struct radix_tree_root *root, - unsigned long index, void *entry) -{ - return __radix_tree_insert(root, index, 0, entry); -} +int radix_tree_insert(struct radix_tree_root *, unsigned long index, + void *); void *__radix_tree_lookup(const struct radix_tree_root *, unsigned long index, struct radix_tree_node **nodep, void __rcu ***slotp); void *radix_tree_lookup(const struct radix_tree_root *, unsigned long); void __rcu **radix_tree_lookup_slot(const struct radix_tree_root *, unsigned long index); -typedef void (*radix_tree_update_node_t)(struct radix_tree_node *); void __radix_tree_replace(struct radix_tree_root *, struct radix_tree_node *, - void __rcu **slot, void *entry, - radix_tree_update_node_t update_node); + void __rcu **slot, void *entry); void radix_tree_iter_replace(struct radix_tree_root *, const struct radix_tree_iter *, void __rcu **slot, void *entry); void radix_tree_replace_slot(struct radix_tree_root *, void __rcu **slot, void *entry); -void __radix_tree_delete_node(struct radix_tree_root *, - struct radix_tree_node *, - radix_tree_update_node_t update_node); void radix_tree_iter_delete(struct radix_tree_root *, struct radix_tree_iter *iter, void __rcu **slot); void *radix_tree_delete_item(struct radix_tree_root *, unsigned long, void *); void *radix_tree_delete(struct radix_tree_root *, unsigned long); -void radix_tree_clear_tags(struct radix_tree_root *, struct radix_tree_node *, - void __rcu **slot); unsigned int radix_tree_gang_lookup(const struct radix_tree_root *, void **results, unsigned long first_index, unsigned int max_items); -unsigned int radix_tree_gang_lookup_slot(const struct radix_tree_root *, - void __rcu ***results, unsigned long *indices, - unsigned long first_index, unsigned int max_items); int radix_tree_preload(gfp_t gfp_mask); int radix_tree_maybe_preload(gfp_t gfp_mask); -int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order); void radix_tree_init(void); void *radix_tree_tag_set(struct radix_tree_root *, unsigned long index, unsigned int tag); @@ -337,8 +246,6 @@ void *radix_tree_tag_clear(struct radix_tree_root *, unsigned long index, unsigned int tag); int radix_tree_tag_get(const struct radix_tree_root *, unsigned long index, unsigned int tag); -void radix_tree_iter_tag_set(struct radix_tree_root *, - const struct radix_tree_iter *iter, unsigned int tag); void radix_tree_iter_tag_clear(struct radix_tree_root *, const struct radix_tree_iter *iter, unsigned int tag); unsigned int radix_tree_gang_lookup_tag(const struct radix_tree_root *, @@ -354,12 +261,6 @@ static inline void radix_tree_preload_end(void) preempt_enable(); } -int radix_tree_split_preload(unsigned old_order, unsigned new_order, gfp_t); -int radix_tree_split(struct radix_tree_root *, unsigned long index, - unsigned new_order); -int radix_tree_join(struct radix_tree_root *, unsigned long index, - unsigned new_order, void *); - void __rcu **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, unsigned long max); @@ -465,7 +366,7 @@ void __rcu **radix_tree_iter_retry(struct radix_tree_iter *iter) static inline unsigned long __radix_tree_iter_add(struct radix_tree_iter *iter, unsigned long slots) { - return iter->index + (slots << iter_shift(iter)); + return iter->index + slots; } /** @@ -490,21 +391,9 @@ void __rcu **__must_check radix_tree_iter_resume(void __rcu **slot, static __always_inline long radix_tree_chunk_size(struct radix_tree_iter *iter) { - return (iter->next_index - iter->index) >> iter_shift(iter); + return iter->next_index - iter->index; } -#ifdef CONFIG_RADIX_TREE_MULTIORDER -void __rcu **__radix_tree_next_slot(void __rcu **slot, - struct radix_tree_iter *iter, unsigned flags); -#else -/* Can't happen without sibling entries, but the compiler can't tell that */ -static inline void __rcu **__radix_tree_next_slot(void __rcu **slot, - struct radix_tree_iter *iter, unsigned flags) -{ - return slot; -} -#endif - /** * radix_tree_next_slot - find next slot in chunk * @@ -563,8 +452,6 @@ static __always_inline void __rcu **radix_tree_next_slot(void __rcu **slot, return NULL; found: - if (unlikely(radix_tree_is_internal_node(rcu_dereference_raw(*slot)))) - return __radix_tree_next_slot(slot, iter, flags); return slot; } @@ -583,23 +470,6 @@ static __always_inline void __rcu **radix_tree_next_slot(void __rcu **slot, slot || (slot = radix_tree_next_chunk(root, iter, 0)) ; \ slot = radix_tree_next_slot(slot, iter, 0)) -/** - * radix_tree_for_each_contig - iterate over contiguous slots - * - * @slot: the void** variable for pointer to slot - * @root: the struct radix_tree_root pointer - * @iter: the struct radix_tree_iter pointer - * @start: iteration starting index - * - * @slot points to radix tree slot, @iter->index contains its index. - */ -#define radix_tree_for_each_contig(slot, root, iter, start) \ - for (slot = radix_tree_iter_init(iter, start) ; \ - slot || (slot = radix_tree_next_chunk(root, iter, \ - RADIX_TREE_ITER_CONTIG)) ; \ - slot = radix_tree_next_slot(slot, iter, \ - RADIX_TREE_ITER_CONTIG)) - /** * radix_tree_for_each_tagged - iterate over tagged slots * diff --git a/include/linux/swap.h b/include/linux/swap.h index 38195f5c96b1..d8a07a4f171d 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -300,17 +300,12 @@ void *workingset_eviction(struct address_space *mapping, struct page *page); void workingset_refault(struct page *page, void *shadow); void workingset_activation(struct page *page); -/* Do not use directly, use workingset_lookup_update */ -void workingset_update_node(struct radix_tree_node *node); - -/* Returns workingset_update_node() if the mapping has shadow entries. */ -#define workingset_lookup_update(mapping) \ -({ \ - radix_tree_update_node_t __helper = workingset_update_node; \ - if (dax_mapping(mapping) || shmem_mapping(mapping)) \ - __helper = NULL; \ - __helper; \ -}) +/* Only track the nodes of mappings with shadow entries */ +void workingset_update_node(struct xa_node *node); +#define mapping_set_update(xas, mapping) do { \ + if (!dax_mapping(mapping) && !shmem_mapping(mapping)) \ + xas_set_update(xas, workingset_update_node); \ +} while (0) /* linux/mm/page_alloc.c */ extern unsigned long totalram_pages; @@ -409,7 +404,7 @@ extern void show_swap_cache_info(void); extern int add_to_swap(struct page *page); extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); extern int __add_to_swap_cache(struct page *page, swp_entry_t entry); -extern void __delete_from_swap_cache(struct page *); +extern void __delete_from_swap_cache(struct page *, swp_entry_t entry); extern void delete_from_swap_cache(struct page *); extern void free_page_and_swap_cache(struct page *); extern void free_pages_and_swap_cache(struct page **, int); @@ -563,7 +558,8 @@ static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, return -1; } -static inline void __delete_from_swap_cache(struct page *page) +static inline void __delete_from_swap_cache(struct page *page, + swp_entry_t entry) { } diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 22af9d8a84ae..4d961668e5fc 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -18,9 +18,8 @@ * * swp_entry_t's are *never* stored anywhere in their arch-dependent format. */ -#define SWP_TYPE_SHIFT(e) ((sizeof(e.val) * 8) - \ - (MAX_SWAPFILES_SHIFT + RADIX_TREE_EXCEPTIONAL_SHIFT)) -#define SWP_OFFSET_MASK(e) ((1UL << SWP_TYPE_SHIFT(e)) - 1) +#define SWP_TYPE_SHIFT (BITS_PER_XA_VALUE - MAX_SWAPFILES_SHIFT) +#define SWP_OFFSET_MASK ((1UL << SWP_TYPE_SHIFT) - 1) /* * Store a type+offset into a swp_entry_t in an arch-independent format @@ -29,8 +28,7 @@ static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset) { swp_entry_t ret; - ret.val = (type << SWP_TYPE_SHIFT(ret)) | - (offset & SWP_OFFSET_MASK(ret)); + ret.val = (type << SWP_TYPE_SHIFT) | (offset & SWP_OFFSET_MASK); return ret; } @@ -40,7 +38,7 @@ static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset) */ static inline unsigned swp_type(swp_entry_t entry) { - return (entry.val >> SWP_TYPE_SHIFT(entry)); + return (entry.val >> SWP_TYPE_SHIFT); } /* @@ -49,7 +47,7 @@ static inline unsigned swp_type(swp_entry_t entry) */ static inline pgoff_t swp_offset(swp_entry_t entry) { - return entry.val & SWP_OFFSET_MASK(entry); + return entry.val & SWP_OFFSET_MASK; } #ifdef CONFIG_MMU @@ -90,16 +88,13 @@ static inline swp_entry_t radix_to_swp_entry(void *arg) { swp_entry_t entry; - entry.val = (unsigned long)arg >> RADIX_TREE_EXCEPTIONAL_SHIFT; + entry.val = xa_to_value(arg); return entry; } static inline void *swp_to_radix_entry(swp_entry_t entry) { - unsigned long value; - - value = entry.val << RADIX_TREE_EXCEPTIONAL_SHIFT; - return (void *)(value | RADIX_TREE_EXCEPTIONAL_ENTRY); + return xa_mk_value(entry.val); } #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 2dfc8006fe64..d9514928ddac 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -4,10 +4,432 @@ /* * eXtensible Arrays * Copyright (c) 2017 Microsoft Corporation - * Author: Matthew Wilcox + * Author: Matthew Wilcox + * + * See Documentation/core-api/xarray.rst for how to use the XArray. */ +#include +#include +#include +#include +#include +#include #include +#include + +/* + * The bottom two bits of the entry determine how the XArray interprets + * the contents: + * + * 00: Pointer entry + * 10: Internal entry + * x1: Value entry or tagged pointer + * + * Attempting to store internal entries in the XArray is a bug. + * + * Most internal entries are pointers to the next node in the tree. + * The following internal entries have a special meaning: + * + * 0-62: Sibling entries + * 256: Zero entry + * 257: Retry entry + * + * Errors are also represented as internal entries, but use the negative + * space (-4094 to -2). They're never stored in the slots array; only + * returned by the normal API. + */ + +#define BITS_PER_XA_VALUE (BITS_PER_LONG - 1) + +/** + * xa_mk_value() - Create an XArray entry from an integer. + * @v: Value to store in XArray. + * + * Context: Any context. + * Return: An entry suitable for storing in the XArray. + */ +static inline void *xa_mk_value(unsigned long v) +{ + WARN_ON((long)v < 0); + return (void *)((v << 1) | 1); +} + +/** + * xa_to_value() - Get value stored in an XArray entry. + * @entry: XArray entry. + * + * Context: Any context. + * Return: The value stored in the XArray entry. + */ +static inline unsigned long xa_to_value(const void *entry) +{ + return (unsigned long)entry >> 1; +} + +/** + * xa_is_value() - Determine if an entry is a value. + * @entry: XArray entry. + * + * Context: Any context. + * Return: True if the entry is a value, false if it is a pointer. + */ +static inline bool xa_is_value(const void *entry) +{ + return (unsigned long)entry & 1; +} + +/** + * xa_tag_pointer() - Create an XArray entry for a tagged pointer. + * @p: Plain pointer. + * @tag: Tag value (0, 1 or 3). + * + * If the user of the XArray prefers, they can tag their pointers instead + * of storing value entries. Three tags are available (0, 1 and 3). + * These are distinct from the xa_mark_t as they are not replicated up + * through the array and cannot be searched for. + * + * Context: Any context. + * Return: An XArray entry. + */ +static inline void *xa_tag_pointer(void *p, unsigned long tag) +{ + return (void *)((unsigned long)p | tag); +} + +/** + * xa_untag_pointer() - Turn an XArray entry into a plain pointer. + * @entry: XArray entry. + * + * If you have stored a tagged pointer in the XArray, call this function + * to get the untagged version of the pointer. + * + * Context: Any context. + * Return: A pointer. + */ +static inline void *xa_untag_pointer(void *entry) +{ + return (void *)((unsigned long)entry & ~3UL); +} + +/** + * xa_pointer_tag() - Get the tag stored in an XArray entry. + * @entry: XArray entry. + * + * If you have stored a tagged pointer in the XArray, call this function + * to get the tag of that pointer. + * + * Context: Any context. + * Return: A tag. + */ +static inline unsigned int xa_pointer_tag(void *entry) +{ + return (unsigned long)entry & 3UL; +} + +/* + * xa_mk_internal() - Create an internal entry. + * @v: Value to turn into an internal entry. + * + * Context: Any context. + * Return: An XArray internal entry corresponding to this value. + */ +static inline void *xa_mk_internal(unsigned long v) +{ + return (void *)((v << 2) | 2); +} + +/* + * xa_to_internal() - Extract the value from an internal entry. + * @entry: XArray entry. + * + * Context: Any context. + * Return: The value which was stored in the internal entry. + */ +static inline unsigned long xa_to_internal(const void *entry) +{ + return (unsigned long)entry >> 2; +} + +/* + * xa_is_internal() - Is the entry an internal entry? + * @entry: XArray entry. + * + * Context: Any context. + * Return: %true if the entry is an internal entry. + */ +static inline bool xa_is_internal(const void *entry) +{ + return ((unsigned long)entry & 3) == 2; +} + +/** + * xa_is_err() - Report whether an XArray operation returned an error + * @entry: Result from calling an XArray function + * + * If an XArray operation cannot complete an operation, it will return + * a special value indicating an error. This function tells you + * whether an error occurred; xa_err() tells you which error occurred. + * + * Context: Any context. + * Return: %true if the entry indicates an error. + */ +static inline bool xa_is_err(const void *entry) +{ + return unlikely(xa_is_internal(entry)); +} + +/** + * xa_err() - Turn an XArray result into an errno. + * @entry: Result from calling an XArray function. + * + * If an XArray operation cannot complete an operation, it will return + * a special pointer value which encodes an errno. This function extracts + * the errno from the pointer value, or returns 0 if the pointer does not + * represent an errno. + * + * Context: Any context. + * Return: A negative errno or 0. + */ +static inline int xa_err(void *entry) +{ + /* xa_to_internal() would not do sign extension. */ + if (xa_is_err(entry)) + return (long)entry >> 2; + return 0; +} + +typedef unsigned __bitwise xa_mark_t; +#define XA_MARK_0 ((__force xa_mark_t)0U) +#define XA_MARK_1 ((__force xa_mark_t)1U) +#define XA_MARK_2 ((__force xa_mark_t)2U) +#define XA_PRESENT ((__force xa_mark_t)8U) +#define XA_MARK_MAX XA_MARK_2 +#define XA_FREE_MARK XA_MARK_0 + +enum xa_lock_type { + XA_LOCK_IRQ = 1, + XA_LOCK_BH = 2, +}; + +/* + * Values for xa_flags. The radix tree stores its GFP flags in the xa_flags, + * and we remain compatible with that. + */ +#define XA_FLAGS_LOCK_IRQ ((__force gfp_t)XA_LOCK_IRQ) +#define XA_FLAGS_LOCK_BH ((__force gfp_t)XA_LOCK_BH) +#define XA_FLAGS_TRACK_FREE ((__force gfp_t)4U) +#define XA_FLAGS_MARK(mark) ((__force gfp_t)((1U << __GFP_BITS_SHIFT) << \ + (__force unsigned)(mark))) + +#define XA_FLAGS_ALLOC (XA_FLAGS_TRACK_FREE | XA_FLAGS_MARK(XA_FREE_MARK)) + +/** + * struct xarray - The anchor of the XArray. + * @xa_lock: Lock that protects the contents of the XArray. + * + * To use the xarray, define it statically or embed it in your data structure. + * It is a very small data structure, so it does not usually make sense to + * allocate it separately and keep a pointer to it in your data structure. + * + * You may use the xa_lock to protect your own data structures as well. + */ +/* + * If all of the entries in the array are NULL, @xa_head is a NULL pointer. + * If the only non-NULL entry in the array is at index 0, @xa_head is that + * entry. If any other entry in the array is non-NULL, @xa_head points + * to an @xa_node. + */ +struct xarray { + spinlock_t xa_lock; +/* private: The rest of the data structure is not to be used directly. */ + gfp_t xa_flags; + void __rcu * xa_head; +}; + +#define XARRAY_INIT(name, flags) { \ + .xa_lock = __SPIN_LOCK_UNLOCKED(name.xa_lock), \ + .xa_flags = flags, \ + .xa_head = NULL, \ +} + +/** + * DEFINE_XARRAY_FLAGS() - Define an XArray with custom flags. + * @name: A string that names your XArray. + * @flags: XA_FLAG values. + * + * This is intended for file scope definitions of XArrays. It declares + * and initialises an empty XArray with the chosen name and flags. It is + * equivalent to calling xa_init_flags() on the array, but it does the + * initialisation at compiletime instead of runtime. + */ +#define DEFINE_XARRAY_FLAGS(name, flags) \ + struct xarray name = XARRAY_INIT(name, flags) + +/** + * DEFINE_XARRAY() - Define an XArray. + * @name: A string that names your XArray. + * + * This is intended for file scope definitions of XArrays. It declares + * and initialises an empty XArray with the chosen name. It is equivalent + * to calling xa_init() on the array, but it does the initialisation at + * compiletime instead of runtime. + */ +#define DEFINE_XARRAY(name) DEFINE_XARRAY_FLAGS(name, 0) + +/** + * DEFINE_XARRAY_ALLOC() - Define an XArray which can allocate IDs. + * @name: A string that names your XArray. + * + * This is intended for file scope definitions of allocating XArrays. + * See also DEFINE_XARRAY(). + */ +#define DEFINE_XARRAY_ALLOC(name) DEFINE_XARRAY_FLAGS(name, XA_FLAGS_ALLOC) + +void xa_init_flags(struct xarray *, gfp_t flags); +void *xa_load(struct xarray *, unsigned long index); +void *xa_store(struct xarray *, unsigned long index, void *entry, gfp_t); +void *xa_cmpxchg(struct xarray *, unsigned long index, + void *old, void *entry, gfp_t); +int xa_reserve(struct xarray *, unsigned long index, gfp_t); +void *xa_store_range(struct xarray *, unsigned long first, unsigned long last, + void *entry, gfp_t); +bool xa_get_mark(struct xarray *, unsigned long index, xa_mark_t); +void xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); +void xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); +void *xa_find(struct xarray *xa, unsigned long *index, + unsigned long max, xa_mark_t) __attribute__((nonnull(2))); +void *xa_find_after(struct xarray *xa, unsigned long *index, + unsigned long max, xa_mark_t) __attribute__((nonnull(2))); +unsigned int xa_extract(struct xarray *, void **dst, unsigned long start, + unsigned long max, unsigned int n, xa_mark_t); +void xa_destroy(struct xarray *); + +/** + * xa_init() - Initialise an empty XArray. + * @xa: XArray. + * + * An empty XArray is full of NULL entries. + * + * Context: Any context. + */ +static inline void xa_init(struct xarray *xa) +{ + xa_init_flags(xa, 0); +} + +/** + * xa_empty() - Determine if an array has any present entries. + * @xa: XArray. + * + * Context: Any context. + * Return: %true if the array contains only NULL pointers. + */ +static inline bool xa_empty(const struct xarray *xa) +{ + return xa->xa_head == NULL; +} + +/** + * xa_marked() - Inquire whether any entry in this array has a mark set + * @xa: Array + * @mark: Mark value + * + * Context: Any context. + * Return: %true if any entry has this mark set. + */ +static inline bool xa_marked(const struct xarray *xa, xa_mark_t mark) +{ + return xa->xa_flags & XA_FLAGS_MARK(mark); +} + +/** + * xa_erase() - Erase this entry from the XArray. + * @xa: XArray. + * @index: Index of entry. + * + * This function is the equivalent of calling xa_store() with %NULL as + * the third argument. The XArray does not need to allocate memory, so + * the user does not need to provide GFP flags. + * + * Context: Process context. Takes and releases the xa_lock. + * Return: The entry which used to be at this index. + */ +static inline void *xa_erase(struct xarray *xa, unsigned long index) +{ + return xa_store(xa, index, NULL, 0); +} + +/** + * xa_insert() - Store this entry in the XArray unless another entry is + * already present. + * @xa: XArray. + * @index: Index into array. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * If you would rather see the existing entry in the array, use xa_cmpxchg(). + * This function is for users who don't care what the entry is, only that + * one is present. + * + * Context: Process context. Takes and releases the xa_lock. + * May sleep if the @gfp flags permit. + * Return: 0 if the store succeeded. -EEXIST if another entry was present. + * -ENOMEM if memory could not be allocated. + */ +static inline int xa_insert(struct xarray *xa, unsigned long index, + void *entry, gfp_t gfp) +{ + void *curr = xa_cmpxchg(xa, index, NULL, entry, gfp); + if (!curr) + return 0; + if (xa_is_err(curr)) + return xa_err(curr); + return -EEXIST; +} + +/** + * xa_release() - Release a reserved entry. + * @xa: XArray. + * @index: Index of entry. + * + * After calling xa_reserve(), you can call this function to release the + * reservation. If the entry at @index has been stored to, this function + * will do nothing. + */ +static inline void xa_release(struct xarray *xa, unsigned long index) +{ + xa_cmpxchg(xa, index, NULL, NULL, 0); +} + +/** + * xa_for_each() - Iterate over a portion of an XArray. + * @xa: XArray. + * @entry: Entry retrieved from array. + * @index: Index of @entry. + * @max: Maximum index to retrieve from array. + * @filter: Selection criterion. + * + * Initialise @index to the lowest index you want to retrieve from the + * array. During the iteration, @entry will have the value of the entry + * stored in @xa at @index. The iteration will skip all entries in the + * array which do not match @filter. You may modify @index during the + * iteration if you want to skip or reprocess indices. It is safe to modify + * the array during the iteration. At the end of the iteration, @entry will + * be set to NULL and @index will have a value less than or equal to max. + * + * xa_for_each() is O(n.log(n)) while xas_for_each() is O(n). You have + * to handle your own locking with xas_for_each(), and if you have to unlock + * after each iteration, it will also end up being O(n.log(n)). xa_for_each() + * will spin if it hits a retry entry; if you intend to see retry entries, + * you should use the xas_for_each() iterator instead. The xas_for_each() + * iterator will expand into more inline code than xa_for_each(). + * + * Context: Any context. Takes and releases the RCU lock. + */ +#define xa_for_each(xa, entry, index, max, filter) \ + for (entry = xa_find(xa, &index, max, filter); entry; \ + entry = xa_find_after(xa, &index, max, filter)) #define xa_trylock(xa) spin_trylock(&(xa)->xa_lock) #define xa_lock(xa) spin_lock(&(xa)->xa_lock) @@ -21,4 +443,873 @@ #define xa_unlock_irqrestore(xa, flags) \ spin_unlock_irqrestore(&(xa)->xa_lock, flags) +/* + * Versions of the normal API which require the caller to hold the + * xa_lock. If the GFP flags allow it, they will drop the lock to + * allocate memory, then reacquire it afterwards. These functions + * may also re-enable interrupts if the XArray flags indicate the + * locking should be interrupt safe. + */ +void *__xa_erase(struct xarray *, unsigned long index); +void *__xa_store(struct xarray *, unsigned long index, void *entry, gfp_t); +void *__xa_cmpxchg(struct xarray *, unsigned long index, void *old, + void *entry, gfp_t); +int __xa_alloc(struct xarray *, u32 *id, u32 max, void *entry, gfp_t); +void __xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); +void __xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); + +/** + * __xa_insert() - Store this entry in the XArray unless another entry is + * already present. + * @xa: XArray. + * @index: Index into array. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * If you would rather see the existing entry in the array, use __xa_cmpxchg(). + * This function is for users who don't care what the entry is, only that + * one is present. + * + * Context: Any context. Expects xa_lock to be held on entry. May + * release and reacquire xa_lock if the @gfp flags permit. + * Return: 0 if the store succeeded. -EEXIST if another entry was present. + * -ENOMEM if memory could not be allocated. + */ +static inline int __xa_insert(struct xarray *xa, unsigned long index, + void *entry, gfp_t gfp) +{ + void *curr = __xa_cmpxchg(xa, index, NULL, entry, gfp); + if (!curr) + return 0; + if (xa_is_err(curr)) + return xa_err(curr); + return -EEXIST; +} + +/** + * xa_erase_bh() - Erase this entry from the XArray. + * @xa: XArray. + * @index: Index of entry. + * + * This function is the equivalent of calling xa_store() with %NULL as + * the third argument. The XArray does not need to allocate memory, so + * the user does not need to provide GFP flags. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling softirqs. + * Return: The entry which used to be at this index. + */ +static inline void *xa_erase_bh(struct xarray *xa, unsigned long index) +{ + void *entry; + + xa_lock_bh(xa); + entry = __xa_erase(xa, index); + xa_unlock_bh(xa); + + return entry; +} + +/** + * xa_erase_irq() - Erase this entry from the XArray. + * @xa: XArray. + * @index: Index of entry. + * + * This function is the equivalent of calling xa_store() with %NULL as + * the third argument. The XArray does not need to allocate memory, so + * the user does not need to provide GFP flags. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling interrupts. + * Return: The entry which used to be at this index. + */ +static inline void *xa_erase_irq(struct xarray *xa, unsigned long index) +{ + void *entry; + + xa_lock_irq(xa); + entry = __xa_erase(xa, index); + xa_unlock_irq(xa); + + return entry; +} + +/** + * xa_alloc() - Find somewhere to store this entry in the XArray. + * @xa: XArray. + * @id: Pointer to ID. + * @max: Maximum ID to allocate (inclusive). + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * Allocates an unused ID in the range specified by @id and @max. + * Updates the @id pointer with the index, then stores the entry at that + * index. A concurrent lookup will not see an uninitialised @id. + * + * Context: Process context. Takes and releases the xa_lock. May sleep if + * the @gfp flags permit. + * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if + * there is no more space in the XArray. + */ +static inline int xa_alloc(struct xarray *xa, u32 *id, u32 max, void *entry, + gfp_t gfp) +{ + int err; + + xa_lock(xa); + err = __xa_alloc(xa, id, max, entry, gfp); + xa_unlock(xa); + + return err; +} + +/** + * xa_alloc_bh() - Find somewhere to store this entry in the XArray. + * @xa: XArray. + * @id: Pointer to ID. + * @max: Maximum ID to allocate (inclusive). + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * Allocates an unused ID in the range specified by @id and @max. + * Updates the @id pointer with the index, then stores the entry at that + * index. A concurrent lookup will not see an uninitialised @id. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling softirqs. May sleep if the @gfp flags permit. + * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if + * there is no more space in the XArray. + */ +static inline int xa_alloc_bh(struct xarray *xa, u32 *id, u32 max, void *entry, + gfp_t gfp) +{ + int err; + + xa_lock_bh(xa); + err = __xa_alloc(xa, id, max, entry, gfp); + xa_unlock_bh(xa); + + return err; +} + +/** + * xa_alloc_irq() - Find somewhere to store this entry in the XArray. + * @xa: XArray. + * @id: Pointer to ID. + * @max: Maximum ID to allocate (inclusive). + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * Allocates an unused ID in the range specified by @id and @max. + * Updates the @id pointer with the index, then stores the entry at that + * index. A concurrent lookup will not see an uninitialised @id. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling interrupts. May sleep if the @gfp flags permit. + * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if + * there is no more space in the XArray. + */ +static inline int xa_alloc_irq(struct xarray *xa, u32 *id, u32 max, void *entry, + gfp_t gfp) +{ + int err; + + xa_lock_irq(xa); + err = __xa_alloc(xa, id, max, entry, gfp); + xa_unlock_irq(xa); + + return err; +} + +/* Everything below here is the Advanced API. Proceed with caution. */ + +/* + * The xarray is constructed out of a set of 'chunks' of pointers. Choosing + * the best chunk size requires some tradeoffs. A power of two recommends + * itself so that we can walk the tree based purely on shifts and masks. + * Generally, the larger the better; as the number of slots per level of the + * tree increases, the less tall the tree needs to be. But that needs to be + * balanced against the memory consumption of each node. On a 64-bit system, + * xa_node is currently 576 bytes, and we get 7 of them per 4kB page. If we + * doubled the number of slots per node, we'd get only 3 nodes per 4kB page. + */ +#ifndef XA_CHUNK_SHIFT +#define XA_CHUNK_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) +#endif +#define XA_CHUNK_SIZE (1UL << XA_CHUNK_SHIFT) +#define XA_CHUNK_MASK (XA_CHUNK_SIZE - 1) +#define XA_MAX_MARKS 3 +#define XA_MARK_LONGS DIV_ROUND_UP(XA_CHUNK_SIZE, BITS_PER_LONG) + +/* + * @count is the count of every non-NULL element in the ->slots array + * whether that is a value entry, a retry entry, a user pointer, + * a sibling entry or a pointer to the next level of the tree. + * @nr_values is the count of every element in ->slots which is + * either a value entry or a sibling of a value entry. + */ +struct xa_node { + unsigned char shift; /* Bits remaining in each slot */ + unsigned char offset; /* Slot offset in parent */ + unsigned char count; /* Total entry count */ + unsigned char nr_values; /* Value entry count */ + struct xa_node __rcu *parent; /* NULL at top of tree */ + struct xarray *array; /* The array we belong to */ + union { + struct list_head private_list; /* For tree user */ + struct rcu_head rcu_head; /* Used when freeing node */ + }; + void __rcu *slots[XA_CHUNK_SIZE]; + union { + unsigned long tags[XA_MAX_MARKS][XA_MARK_LONGS]; + unsigned long marks[XA_MAX_MARKS][XA_MARK_LONGS]; + }; +}; + +void xa_dump(const struct xarray *); +void xa_dump_node(const struct xa_node *); + +#ifdef XA_DEBUG +#define XA_BUG_ON(xa, x) do { \ + if (x) { \ + xa_dump(xa); \ + BUG(); \ + } \ + } while (0) +#define XA_NODE_BUG_ON(node, x) do { \ + if (x) { \ + if (node) xa_dump_node(node); \ + BUG(); \ + } \ + } while (0) +#else +#define XA_BUG_ON(xa, x) do { } while (0) +#define XA_NODE_BUG_ON(node, x) do { } while (0) +#endif + +/* Private */ +static inline void *xa_head(const struct xarray *xa) +{ + return rcu_dereference_check(xa->xa_head, + lockdep_is_held(&xa->xa_lock)); +} + +/* Private */ +static inline void *xa_head_locked(const struct xarray *xa) +{ + return rcu_dereference_protected(xa->xa_head, + lockdep_is_held(&xa->xa_lock)); +} + +/* Private */ +static inline void *xa_entry(const struct xarray *xa, + const struct xa_node *node, unsigned int offset) +{ + XA_NODE_BUG_ON(node, offset >= XA_CHUNK_SIZE); + return rcu_dereference_check(node->slots[offset], + lockdep_is_held(&xa->xa_lock)); +} + +/* Private */ +static inline void *xa_entry_locked(const struct xarray *xa, + const struct xa_node *node, unsigned int offset) +{ + XA_NODE_BUG_ON(node, offset >= XA_CHUNK_SIZE); + return rcu_dereference_protected(node->slots[offset], + lockdep_is_held(&xa->xa_lock)); +} + +/* Private */ +static inline struct xa_node *xa_parent(const struct xarray *xa, + const struct xa_node *node) +{ + return rcu_dereference_check(node->parent, + lockdep_is_held(&xa->xa_lock)); +} + +/* Private */ +static inline struct xa_node *xa_parent_locked(const struct xarray *xa, + const struct xa_node *node) +{ + return rcu_dereference_protected(node->parent, + lockdep_is_held(&xa->xa_lock)); +} + +/* Private */ +static inline void *xa_mk_node(const struct xa_node *node) +{ + return (void *)((unsigned long)node | 2); +} + +/* Private */ +static inline struct xa_node *xa_to_node(const void *entry) +{ + return (struct xa_node *)((unsigned long)entry - 2); +} + +/* Private */ +static inline bool xa_is_node(const void *entry) +{ + return xa_is_internal(entry) && (unsigned long)entry > 4096; +} + +/* Private */ +static inline void *xa_mk_sibling(unsigned int offset) +{ + return xa_mk_internal(offset); +} + +/* Private */ +static inline unsigned long xa_to_sibling(const void *entry) +{ + return xa_to_internal(entry); +} + +/** + * xa_is_sibling() - Is the entry a sibling entry? + * @entry: Entry retrieved from the XArray + * + * Return: %true if the entry is a sibling entry. + */ +static inline bool xa_is_sibling(const void *entry) +{ + return IS_ENABLED(CONFIG_XARRAY_MULTI) && xa_is_internal(entry) && + (entry < xa_mk_sibling(XA_CHUNK_SIZE - 1)); +} + +#define XA_ZERO_ENTRY xa_mk_internal(256) +#define XA_RETRY_ENTRY xa_mk_internal(257) + +/** + * xa_is_zero() - Is the entry a zero entry? + * @entry: Entry retrieved from the XArray + * + * Return: %true if the entry is a zero entry. + */ +static inline bool xa_is_zero(const void *entry) +{ + return unlikely(entry == XA_ZERO_ENTRY); +} + +/** + * xa_is_retry() - Is the entry a retry entry? + * @entry: Entry retrieved from the XArray + * + * Return: %true if the entry is a retry entry. + */ +static inline bool xa_is_retry(const void *entry) +{ + return unlikely(entry == XA_RETRY_ENTRY); +} + +/** + * typedef xa_update_node_t - A callback function from the XArray. + * @node: The node which is being processed + * + * This function is called every time the XArray updates the count of + * present and value entries in a node. It allows advanced users to + * maintain the private_list in the node. + * + * Context: The xa_lock is held and interrupts may be disabled. + * Implementations should not drop the xa_lock, nor re-enable + * interrupts. + */ +typedef void (*xa_update_node_t)(struct xa_node *node); + +/* + * The xa_state is opaque to its users. It contains various different pieces + * of state involved in the current operation on the XArray. It should be + * declared on the stack and passed between the various internal routines. + * The various elements in it should not be accessed directly, but only + * through the provided accessor functions. The below documentation is for + * the benefit of those working on the code, not for users of the XArray. + * + * @xa_node usually points to the xa_node containing the slot we're operating + * on (and @xa_offset is the offset in the slots array). If there is a + * single entry in the array at index 0, there are no allocated xa_nodes to + * point to, and so we store %NULL in @xa_node. @xa_node is set to + * the value %XAS_RESTART if the xa_state is not walked to the correct + * position in the tree of nodes for this operation. If an error occurs + * during an operation, it is set to an %XAS_ERROR value. If we run off the + * end of the allocated nodes, it is set to %XAS_BOUNDS. + */ +struct xa_state { + struct xarray *xa; + unsigned long xa_index; + unsigned char xa_shift; + unsigned char xa_sibs; + unsigned char xa_offset; + unsigned char xa_pad; /* Helps gcc generate better code */ + struct xa_node *xa_node; + struct xa_node *xa_alloc; + xa_update_node_t xa_update; +}; + +/* + * We encode errnos in the xas->xa_node. If an error has happened, we need to + * drop the lock to fix it, and once we've done so the xa_state is invalid. + */ +#define XA_ERROR(errno) ((struct xa_node *)(((unsigned long)errno << 2) | 2UL)) +#define XAS_BOUNDS ((struct xa_node *)1UL) +#define XAS_RESTART ((struct xa_node *)3UL) + +#define __XA_STATE(array, index, shift, sibs) { \ + .xa = array, \ + .xa_index = index, \ + .xa_shift = shift, \ + .xa_sibs = sibs, \ + .xa_offset = 0, \ + .xa_pad = 0, \ + .xa_node = XAS_RESTART, \ + .xa_alloc = NULL, \ + .xa_update = NULL \ +} + +/** + * XA_STATE() - Declare an XArray operation state. + * @name: Name of this operation state (usually xas). + * @array: Array to operate on. + * @index: Initial index of interest. + * + * Declare and initialise an xa_state on the stack. + */ +#define XA_STATE(name, array, index) \ + struct xa_state name = __XA_STATE(array, index, 0, 0) + +/** + * XA_STATE_ORDER() - Declare an XArray operation state. + * @name: Name of this operation state (usually xas). + * @array: Array to operate on. + * @index: Initial index of interest. + * @order: Order of entry. + * + * Declare and initialise an xa_state on the stack. This variant of + * XA_STATE() allows you to specify the 'order' of the element you + * want to operate on.` + */ +#define XA_STATE_ORDER(name, array, index, order) \ + struct xa_state name = __XA_STATE(array, \ + (index >> order) << order, \ + order - (order % XA_CHUNK_SHIFT), \ + (1U << (order % XA_CHUNK_SHIFT)) - 1) + +#define xas_marked(xas, mark) xa_marked((xas)->xa, (mark)) +#define xas_trylock(xas) xa_trylock((xas)->xa) +#define xas_lock(xas) xa_lock((xas)->xa) +#define xas_unlock(xas) xa_unlock((xas)->xa) +#define xas_lock_bh(xas) xa_lock_bh((xas)->xa) +#define xas_unlock_bh(xas) xa_unlock_bh((xas)->xa) +#define xas_lock_irq(xas) xa_lock_irq((xas)->xa) +#define xas_unlock_irq(xas) xa_unlock_irq((xas)->xa) +#define xas_lock_irqsave(xas, flags) \ + xa_lock_irqsave((xas)->xa, flags) +#define xas_unlock_irqrestore(xas, flags) \ + xa_unlock_irqrestore((xas)->xa, flags) + +/** + * xas_error() - Return an errno stored in the xa_state. + * @xas: XArray operation state. + * + * Return: 0 if no error has been noted. A negative errno if one has. + */ +static inline int xas_error(const struct xa_state *xas) +{ + return xa_err(xas->xa_node); +} + +/** + * xas_set_err() - Note an error in the xa_state. + * @xas: XArray operation state. + * @err: Negative error number. + * + * Only call this function with a negative @err; zero or positive errors + * will probably not behave the way you think they should. If you want + * to clear the error from an xa_state, use xas_reset(). + */ +static inline void xas_set_err(struct xa_state *xas, long err) +{ + xas->xa_node = XA_ERROR(err); +} + +/** + * xas_invalid() - Is the xas in a retry or error state? + * @xas: XArray operation state. + * + * Return: %true if the xas cannot be used for operations. + */ +static inline bool xas_invalid(const struct xa_state *xas) +{ + return (unsigned long)xas->xa_node & 3; +} + +/** + * xas_valid() - Is the xas a valid cursor into the array? + * @xas: XArray operation state. + * + * Return: %true if the xas can be used for operations. + */ +static inline bool xas_valid(const struct xa_state *xas) +{ + return !xas_invalid(xas); +} + +/** + * xas_is_node() - Does the xas point to a node? + * @xas: XArray operation state. + * + * Return: %true if the xas currently references a node. + */ +static inline bool xas_is_node(const struct xa_state *xas) +{ + return xas_valid(xas) && xas->xa_node; +} + +/* True if the pointer is something other than a node */ +static inline bool xas_not_node(struct xa_node *node) +{ + return ((unsigned long)node & 3) || !node; +} + +/* True if the node represents RESTART or an error */ +static inline bool xas_frozen(struct xa_node *node) +{ + return (unsigned long)node & 2; +} + +/* True if the node represents head-of-tree, RESTART or BOUNDS */ +static inline bool xas_top(struct xa_node *node) +{ + return node <= XAS_RESTART; +} + +/** + * xas_reset() - Reset an XArray operation state. + * @xas: XArray operation state. + * + * Resets the error or walk state of the @xas so future walks of the + * array will start from the root. Use this if you have dropped the + * xarray lock and want to reuse the xa_state. + * + * Context: Any context. + */ +static inline void xas_reset(struct xa_state *xas) +{ + xas->xa_node = XAS_RESTART; +} + +/** + * xas_retry() - Retry the operation if appropriate. + * @xas: XArray operation state. + * @entry: Entry from xarray. + * + * The advanced functions may sometimes return an internal entry, such as + * a retry entry or a zero entry. This function sets up the @xas to restart + * the walk from the head of the array if needed. + * + * Context: Any context. + * Return: true if the operation needs to be retried. + */ +static inline bool xas_retry(struct xa_state *xas, const void *entry) +{ + if (xa_is_zero(entry)) + return true; + if (!xa_is_retry(entry)) + return false; + xas_reset(xas); + return true; +} + +void *xas_load(struct xa_state *); +void *xas_store(struct xa_state *, void *entry); +void *xas_find(struct xa_state *, unsigned long max); +void *xas_find_conflict(struct xa_state *); + +bool xas_get_mark(const struct xa_state *, xa_mark_t); +void xas_set_mark(const struct xa_state *, xa_mark_t); +void xas_clear_mark(const struct xa_state *, xa_mark_t); +void *xas_find_marked(struct xa_state *, unsigned long max, xa_mark_t); +void xas_init_marks(const struct xa_state *); + +bool xas_nomem(struct xa_state *, gfp_t); +void xas_pause(struct xa_state *); + +void xas_create_range(struct xa_state *); + +/** + * xas_reload() - Refetch an entry from the xarray. + * @xas: XArray operation state. + * + * Use this function to check that a previously loaded entry still has + * the same value. This is useful for the lockless pagecache lookup where + * we walk the array with only the RCU lock to protect us, lock the page, + * then check that the page hasn't moved since we looked it up. + * + * The caller guarantees that @xas is still valid. If it may be in an + * error or restart state, call xas_load() instead. + * + * Return: The entry at this location in the xarray. + */ +static inline void *xas_reload(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (node) + return xa_entry(xas->xa, node, xas->xa_offset); + return xa_head(xas->xa); +} + +/** + * xas_set() - Set up XArray operation state for a different index. + * @xas: XArray operation state. + * @index: New index into the XArray. + * + * Move the operation state to refer to a different index. This will + * have the effect of starting a walk from the top; see xas_next() + * to move to an adjacent index. + */ +static inline void xas_set(struct xa_state *xas, unsigned long index) +{ + xas->xa_index = index; + xas->xa_node = XAS_RESTART; +} + +/** + * xas_set_order() - Set up XArray operation state for a multislot entry. + * @xas: XArray operation state. + * @index: Target of the operation. + * @order: Entry occupies 2^@order indices. + */ +static inline void xas_set_order(struct xa_state *xas, unsigned long index, + unsigned int order) +{ +#ifdef CONFIG_XARRAY_MULTI + xas->xa_index = order < BITS_PER_LONG ? (index >> order) << order : 0; + xas->xa_shift = order - (order % XA_CHUNK_SHIFT); + xas->xa_sibs = (1 << (order % XA_CHUNK_SHIFT)) - 1; + xas->xa_node = XAS_RESTART; +#else + BUG_ON(order > 0); + xas_set(xas, index); +#endif +} + +/** + * xas_set_update() - Set up XArray operation state for a callback. + * @xas: XArray operation state. + * @update: Function to call when updating a node. + * + * The XArray can notify a caller after it has updated an xa_node. + * This is advanced functionality and is only needed by the page cache. + */ +static inline void xas_set_update(struct xa_state *xas, xa_update_node_t update) +{ + xas->xa_update = update; +} + +/** + * xas_next_entry() - Advance iterator to next present entry. + * @xas: XArray operation state. + * @max: Highest index to return. + * + * xas_next_entry() is an inline function to optimise xarray traversal for + * speed. It is equivalent to calling xas_find(), and will call xas_find() + * for all the hard cases. + * + * Return: The next present entry after the one currently referred to by @xas. + */ +static inline void *xas_next_entry(struct xa_state *xas, unsigned long max) +{ + struct xa_node *node = xas->xa_node; + void *entry; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset != (xas->xa_index & XA_CHUNK_MASK))) + return xas_find(xas, max); + + do { + if (unlikely(xas->xa_index >= max)) + return xas_find(xas, max); + if (unlikely(xas->xa_offset == XA_CHUNK_MASK)) + return xas_find(xas, max); + entry = xa_entry(xas->xa, node, xas->xa_offset + 1); + if (unlikely(xa_is_internal(entry))) + return xas_find(xas, max); + xas->xa_offset++; + xas->xa_index++; + } while (!entry); + + return entry; +} + +/* Private */ +static inline unsigned int xas_find_chunk(struct xa_state *xas, bool advance, + xa_mark_t mark) +{ + unsigned long *addr = xas->xa_node->marks[(__force unsigned)mark]; + unsigned int offset = xas->xa_offset; + + if (advance) + offset++; + if (XA_CHUNK_SIZE == BITS_PER_LONG) { + if (offset < XA_CHUNK_SIZE) { + unsigned long data = *addr & (~0UL << offset); + if (data) + return __ffs(data); + } + return XA_CHUNK_SIZE; + } + + return find_next_bit(addr, XA_CHUNK_SIZE, offset); +} + +/** + * xas_next_marked() - Advance iterator to next marked entry. + * @xas: XArray operation state. + * @max: Highest index to return. + * @mark: Mark to search for. + * + * xas_next_marked() is an inline function to optimise xarray traversal for + * speed. It is equivalent to calling xas_find_marked(), and will call + * xas_find_marked() for all the hard cases. + * + * Return: The next marked entry after the one currently referred to by @xas. + */ +static inline void *xas_next_marked(struct xa_state *xas, unsigned long max, + xa_mark_t mark) +{ + struct xa_node *node = xas->xa_node; + unsigned int offset; + + if (unlikely(xas_not_node(node) || node->shift)) + return xas_find_marked(xas, max, mark); + offset = xas_find_chunk(xas, true, mark); + xas->xa_offset = offset; + xas->xa_index = (xas->xa_index & ~XA_CHUNK_MASK) + offset; + if (xas->xa_index > max) + return NULL; + if (offset == XA_CHUNK_SIZE) + return xas_find_marked(xas, max, mark); + return xa_entry(xas->xa, node, offset); +} + +/* + * If iterating while holding a lock, drop the lock and reschedule + * every %XA_CHECK_SCHED loops. + */ +enum { + XA_CHECK_SCHED = 4096, +}; + +/** + * xas_for_each() - Iterate over a range of an XArray. + * @xas: XArray operation state. + * @entry: Entry retrieved from the array. + * @max: Maximum index to retrieve from array. + * + * The loop body will be executed for each entry present in the xarray + * between the current xas position and @max. @entry will be set to + * the entry retrieved from the xarray. It is safe to delete entries + * from the array in the loop body. You should hold either the RCU lock + * or the xa_lock while iterating. If you need to drop the lock, call + * xas_pause() first. + */ +#define xas_for_each(xas, entry, max) \ + for (entry = xas_find(xas, max); entry; \ + entry = xas_next_entry(xas, max)) + +/** + * xas_for_each_marked() - Iterate over a range of an XArray. + * @xas: XArray operation state. + * @entry: Entry retrieved from the array. + * @max: Maximum index to retrieve from array. + * @mark: Mark to search for. + * + * The loop body will be executed for each marked entry in the xarray + * between the current xas position and @max. @entry will be set to + * the entry retrieved from the xarray. It is safe to delete entries + * from the array in the loop body. You should hold either the RCU lock + * or the xa_lock while iterating. If you need to drop the lock, call + * xas_pause() first. + */ +#define xas_for_each_marked(xas, entry, max, mark) \ + for (entry = xas_find_marked(xas, max, mark); entry; \ + entry = xas_next_marked(xas, max, mark)) + +/** + * xas_for_each_conflict() - Iterate over a range of an XArray. + * @xas: XArray operation state. + * @entry: Entry retrieved from the array. + * + * The loop body will be executed for each entry in the XArray that lies + * within the range specified by @xas. If the loop completes successfully, + * any entries that lie in this range will be replaced by @entry. The caller + * may break out of the loop; if they do so, the contents of the XArray will + * be unchanged. The operation may fail due to an out of memory condition. + * The caller may also call xa_set_err() to exit the loop while setting an + * error to record the reason. + */ +#define xas_for_each_conflict(xas, entry) \ + while ((entry = xas_find_conflict(xas))) + +void *__xas_next(struct xa_state *); +void *__xas_prev(struct xa_state *); + +/** + * xas_prev() - Move iterator to previous index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * subtracted from the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index 0, this function wraps + * around to %ULONG_MAX. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry. + */ +static inline void *xas_prev(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == 0)) + return __xas_prev(xas); + + xas->xa_index--; + xas->xa_offset--; + return xa_entry(xas->xa, node, xas->xa_offset); +} + +/** + * xas_next() - Move state to next index. + * @xas: XArray operation state. + * + * If the @xas was in an error state, it will remain in an error state + * and this function will return %NULL. If the @xas has never been walked, + * it will have the effect of calling xas_load(). Otherwise one will be + * added to the index and the state will be walked to the correct + * location in the array for the next operation. + * + * If the iterator was referencing index %ULONG_MAX, this function wraps + * around to 0. + * + * Return: The entry at the new index. This may be %NULL or an internal + * entry. + */ +static inline void *xas_next(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (unlikely(xas_not_node(node) || node->shift || + xas->xa_offset == XA_CHUNK_MASK)) + return __xas_next(xas); + + xas->xa_index++; + xas->xa_offset++; + return xa_entry(xas->xa, node, xas->xa_offset); +} + #endif /* _LINUX_XARRAY_H */ diff --git a/kernel/memremap.c b/kernel/memremap.c index 620fc4d2559a..9eced2cc9f94 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -1,47 +1,21 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* Copyright(c) 2015 Intel Corporation. All rights reserved. */ -#include #include -#include -#include #include #include -#include #include +#include +#include #include #include +#include #include +#include -static DEFINE_MUTEX(pgmap_lock); -static RADIX_TREE(pgmap_radix, GFP_KERNEL); +static DEFINE_XARRAY(pgmap_array); #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) #define SECTION_SIZE (1UL << PA_SECTION_SHIFT) -static unsigned long order_at(struct resource *res, unsigned long pgoff) -{ - unsigned long phys_pgoff = PHYS_PFN(res->start) + pgoff; - unsigned long nr_pages, mask; - - nr_pages = PHYS_PFN(resource_size(res)); - if (nr_pages == pgoff) - return ULONG_MAX; - - /* - * What is the largest aligned power-of-2 range available from - * this resource pgoff to the end of the resource range, - * considering the alignment of the current pgoff? - */ - mask = phys_pgoff | rounddown_pow_of_two(nr_pages - pgoff); - if (!mask) - return ULONG_MAX; - - return find_first_bit(&mask, BITS_PER_LONG); -} - -#define foreach_order_pgoff(res, order, pgoff) \ - for (pgoff = 0, order = order_at((res), pgoff); order < ULONG_MAX; \ - pgoff += 1UL << order, order = order_at((res), pgoff)) - #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) vm_fault_t device_private_entry_fault(struct vm_area_struct *vma, unsigned long addr, @@ -70,18 +44,10 @@ vm_fault_t device_private_entry_fault(struct vm_area_struct *vma, EXPORT_SYMBOL(device_private_entry_fault); #endif /* CONFIG_DEVICE_PRIVATE */ -static void pgmap_radix_release(struct resource *res, unsigned long end_pgoff) +static void pgmap_array_delete(struct resource *res) { - unsigned long pgoff, order; - - mutex_lock(&pgmap_lock); - foreach_order_pgoff(res, order, pgoff) { - if (pgoff >= end_pgoff) - break; - radix_tree_delete(&pgmap_radix, PHYS_PFN(res->start) + pgoff); - } - mutex_unlock(&pgmap_lock); - + xa_store_range(&pgmap_array, PHYS_PFN(res->start), PHYS_PFN(res->end), + NULL, GFP_KERNEL); synchronize_rcu(); } @@ -142,7 +108,7 @@ static void devm_memremap_pages_release(void *data) mem_hotplug_done(); untrack_pfn(NULL, PHYS_PFN(align_start), align_size); - pgmap_radix_release(res, -1); + pgmap_array_delete(res); dev_WARN_ONCE(dev, pgmap->altmap.alloc, "%s: failed to free all reserved pages\n", __func__); } @@ -177,7 +143,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) struct resource *res = &pgmap->res; struct dev_pagemap *conflict_pgmap; pgprot_t pgprot = PAGE_KERNEL; - unsigned long pgoff, order; int error, nid, is_ram; align_start = res->start & ~(SECTION_SIZE - 1); @@ -216,20 +181,10 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) pgmap->dev = dev; - mutex_lock(&pgmap_lock); - error = 0; - - foreach_order_pgoff(res, order, pgoff) { - error = __radix_tree_insert(&pgmap_radix, - PHYS_PFN(res->start) + pgoff, order, pgmap); - if (error) { - dev_err(dev, "%s: failed: %d\n", __func__, error); - break; - } - } - mutex_unlock(&pgmap_lock); + error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(res->start), + PHYS_PFN(res->end), pgmap, GFP_KERNEL)); if (error) - goto err_radix; + goto err_array; nid = dev_to_node(dev); if (nid < 0) @@ -274,8 +229,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) err_kasan: untrack_pfn(NULL, PHYS_PFN(align_start), align_size); err_pfn_remap: - err_radix: - pgmap_radix_release(res, pgoff); + pgmap_array_delete(res); + err_array: return ERR_PTR(error); } EXPORT_SYMBOL(devm_memremap_pages); @@ -315,7 +270,7 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn, /* fall back to slow path lookup */ rcu_read_lock(); - pgmap = radix_tree_lookup(&pgmap_radix, PHYS_PFN(phys)); + pgmap = xa_load(&pgmap_array, PHYS_PFN(phys)); if (pgmap && !percpu_ref_tryget_live(pgmap->ref)) pgmap = NULL; rcu_read_unlock(); diff --git a/lib/Kconfig b/lib/Kconfig index d82f20609939..d1573a16aa92 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -399,8 +399,11 @@ config INTERVAL_TREE for more information. -config RADIX_TREE_MULTIORDER +config XARRAY_MULTI bool + help + Support entries which occupy multiple consecutive indices in the + XArray. config ASSOCIATIVE_ARRAY bool diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 04adfc3b185e..e0ba05e6f6bd 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1813,6 +1813,9 @@ config TEST_BITFIELD config TEST_UUID tristate "Test functions located in the uuid module at runtime" +config TEST_XARRAY + tristate "Test the XArray code at runtime" + config TEST_OVERFLOW tristate "Test check_*_overflow() functions at runtime" diff --git a/lib/Makefile b/lib/Makefile index fa3eb1b4c0e3..3d341f59f756 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -18,7 +18,7 @@ KCOV_INSTRUMENT_debugobjects.o := n KCOV_INSTRUMENT_dynamic_debug.o := n lib-y := ctype.o string.o vsprintf.o cmdline.o \ - rbtree.o radix-tree.o timerqueue.o\ + rbtree.o radix-tree.o timerqueue.o xarray.o \ idr.o int_sqrt.o extable.o \ sha1.o chacha20.o irq_regs.o argv_split.o \ flex_proportions.o ratelimit.o show_mem.o \ @@ -68,6 +68,7 @@ obj-$(CONFIG_TEST_PRINTF) += test_printf.o obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o obj-$(CONFIG_TEST_BITFIELD) += test_bitfield.o obj-$(CONFIG_TEST_UUID) += test_uuid.o +obj-$(CONFIG_TEST_XARRAY) += test_xarray.o obj-$(CONFIG_TEST_PARMAN) += test_parman.o obj-$(CONFIG_TEST_KMOD) += test_kmod.o obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o diff --git a/lib/idr.c b/lib/idr.c index fab2fd5bc326..cb1db9b8d3f6 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -6,8 +6,6 @@ #include #include -DEFINE_PER_CPU(struct ida_bitmap *, ida_bitmap); - /** * idr_alloc_u32() - Allocate an ID. * @idr: IDR handle. @@ -39,10 +37,8 @@ int idr_alloc_u32(struct idr *idr, void *ptr, u32 *nextid, unsigned int base = idr->idr_base; unsigned int id = *nextid; - if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr))) - return -EINVAL; - if (WARN_ON_ONCE(!(idr->idr_rt.gfp_mask & ROOT_IS_IDR))) - idr->idr_rt.gfp_mask |= IDR_RT_MARKER; + if (WARN_ON_ONCE(!(idr->idr_rt.xa_flags & ROOT_IS_IDR))) + idr->idr_rt.xa_flags |= IDR_RT_MARKER; id = (id < base) ? 0 : id - base; radix_tree_iter_init(&iter, id); @@ -295,15 +291,13 @@ void *idr_replace(struct idr *idr, void *ptr, unsigned long id) void __rcu **slot = NULL; void *entry; - if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr))) - return ERR_PTR(-EINVAL); id -= idr->idr_base; entry = __radix_tree_lookup(&idr->idr_rt, id, &node, &slot); if (!slot || radix_tree_tag_get(&idr->idr_rt, id, IDR_FREE)) return ERR_PTR(-ENOENT); - __radix_tree_replace(&idr->idr_rt, node, slot, ptr, NULL); + __radix_tree_replace(&idr->idr_rt, node, slot, ptr); return entry; } @@ -324,6 +318,9 @@ EXPORT_SYMBOL(idr_replace); * free the individual IDs in it. You can use ida_is_empty() to find * out whether the IDA has any IDs currently allocated. * + * The IDA handles its own locking. It is safe to call any of the IDA + * functions without synchronisation in your code. + * * IDs are currently limited to the range [0-INT_MAX]. If this is an awkward * limitation, it should be quite straightforward to raise the maximum. */ @@ -331,190 +328,38 @@ EXPORT_SYMBOL(idr_replace); /* * Developer's notes: * - * The IDA uses the functionality provided by the IDR & radix tree to store - * bitmaps in each entry. The IDR_FREE tag means there is at least one bit - * free, unlike the IDR where it means at least one entry is free. + * The IDA uses the functionality provided by the XArray to store bitmaps in + * each entry. The XA_FREE_MARK is only cleared when all bits in the bitmap + * have been set. * - * I considered telling the radix tree that each slot is an order-10 node - * and storing the bit numbers in the radix tree, but the radix tree can't - * allow a single multiorder entry at index 0, which would significantly - * increase memory consumption for the IDA. So instead we divide the index - * by the number of bits in the leaf bitmap before doing a radix tree lookup. + * I considered telling the XArray that each slot is an order-10 node + * and indexing by bit number, but the XArray can't allow a single multi-index + * entry in the head, which would significantly increase memory consumption + * for the IDA. So instead we divide the index by the number of bits in the + * leaf bitmap before doing a radix tree lookup. * * As an optimisation, if there are only a few low bits set in any given - * leaf, instead of allocating a 128-byte bitmap, we use the 'exceptional - * entry' functionality of the radix tree to store BITS_PER_LONG - 2 bits - * directly in the entry. By being really tricksy, we could store - * BITS_PER_LONG - 1 bits, but there're diminishing returns after optimising - * for 0-3 allocated IDs. + * leaf, instead of allocating a 128-byte bitmap, we store the bits + * as a value entry. Value entries never have the XA_FREE_MARK cleared + * because we can always convert them into a bitmap entry. * - * We allow the radix tree 'exceptional' count to get out of date. Nothing - * in the IDA nor the radix tree code checks it. If it becomes important - * to maintain an accurate exceptional count, switch the rcu_assign_pointer() - * calls to radix_tree_iter_replace() which will correct the exceptional - * count. + * It would be possible to optimise further; once we've run out of a + * single 128-byte bitmap, we currently switch to a 576-byte node, put + * the 128-byte bitmap in the first entry and then start allocating extra + * 128-byte entries. We could instead use the 512 bytes of the node's + * data as a bitmap before moving to that scheme. I do not believe this + * is a worthwhile optimisation; Rasmus Villemoes surveyed the current + * users of the IDA and almost none of them use more than 1024 entries. + * Those that do use more than the 8192 IDs that the 512 bytes would + * provide. * - * The IDA always requires a lock to alloc/free. If we add a 'test_bit' + * The IDA always uses a lock to alloc/free. If we add a 'test_bit' * equivalent, it will still need locking. Going to RCU lookup would require * using RCU to free bitmaps, and that's not trivial without embedding an * RCU head in the bitmap, which adds a 2-pointer overhead to each 128-byte * bitmap, which is excessive. */ -#define IDA_MAX (0x80000000U / IDA_BITMAP_BITS - 1) - -static int ida_get_new_above(struct ida *ida, int start) -{ - struct radix_tree_root *root = &ida->ida_rt; - void __rcu **slot; - struct radix_tree_iter iter; - struct ida_bitmap *bitmap; - unsigned long index; - unsigned bit, ebit; - int new; - - index = start / IDA_BITMAP_BITS; - bit = start % IDA_BITMAP_BITS; - ebit = bit + RADIX_TREE_EXCEPTIONAL_SHIFT; - - slot = radix_tree_iter_init(&iter, index); - for (;;) { - if (slot) - slot = radix_tree_next_slot(slot, &iter, - RADIX_TREE_ITER_TAGGED); - if (!slot) { - slot = idr_get_free(root, &iter, GFP_NOWAIT, IDA_MAX); - if (IS_ERR(slot)) { - if (slot == ERR_PTR(-ENOMEM)) - return -EAGAIN; - return PTR_ERR(slot); - } - } - if (iter.index > index) { - bit = 0; - ebit = RADIX_TREE_EXCEPTIONAL_SHIFT; - } - new = iter.index * IDA_BITMAP_BITS; - bitmap = rcu_dereference_raw(*slot); - if (radix_tree_exception(bitmap)) { - unsigned long tmp = (unsigned long)bitmap; - ebit = find_next_zero_bit(&tmp, BITS_PER_LONG, ebit); - if (ebit < BITS_PER_LONG) { - tmp |= 1UL << ebit; - rcu_assign_pointer(*slot, (void *)tmp); - return new + ebit - - RADIX_TREE_EXCEPTIONAL_SHIFT; - } - bitmap = this_cpu_xchg(ida_bitmap, NULL); - if (!bitmap) - return -EAGAIN; - bitmap->bitmap[0] = tmp >> RADIX_TREE_EXCEPTIONAL_SHIFT; - rcu_assign_pointer(*slot, bitmap); - } - - if (bitmap) { - bit = find_next_zero_bit(bitmap->bitmap, - IDA_BITMAP_BITS, bit); - new += bit; - if (new < 0) - return -ENOSPC; - if (bit == IDA_BITMAP_BITS) - continue; - - __set_bit(bit, bitmap->bitmap); - if (bitmap_full(bitmap->bitmap, IDA_BITMAP_BITS)) - radix_tree_iter_tag_clear(root, &iter, - IDR_FREE); - } else { - new += bit; - if (new < 0) - return -ENOSPC; - if (ebit < BITS_PER_LONG) { - bitmap = (void *)((1UL << ebit) | - RADIX_TREE_EXCEPTIONAL_ENTRY); - radix_tree_iter_replace(root, &iter, slot, - bitmap); - return new; - } - bitmap = this_cpu_xchg(ida_bitmap, NULL); - if (!bitmap) - return -EAGAIN; - __set_bit(bit, bitmap->bitmap); - radix_tree_iter_replace(root, &iter, slot, bitmap); - } - - return new; - } -} - -static void ida_remove(struct ida *ida, int id) -{ - unsigned long index = id / IDA_BITMAP_BITS; - unsigned offset = id % IDA_BITMAP_BITS; - struct ida_bitmap *bitmap; - unsigned long *btmp; - struct radix_tree_iter iter; - void __rcu **slot; - - slot = radix_tree_iter_lookup(&ida->ida_rt, &iter, index); - if (!slot) - goto err; - - bitmap = rcu_dereference_raw(*slot); - if (radix_tree_exception(bitmap)) { - btmp = (unsigned long *)slot; - offset += RADIX_TREE_EXCEPTIONAL_SHIFT; - if (offset >= BITS_PER_LONG) - goto err; - } else { - btmp = bitmap->bitmap; - } - if (!test_bit(offset, btmp)) - goto err; - - __clear_bit(offset, btmp); - radix_tree_iter_tag_set(&ida->ida_rt, &iter, IDR_FREE); - if (radix_tree_exception(bitmap)) { - if (rcu_dereference_raw(*slot) == - (void *)RADIX_TREE_EXCEPTIONAL_ENTRY) - radix_tree_iter_delete(&ida->ida_rt, &iter, slot); - } else if (bitmap_empty(btmp, IDA_BITMAP_BITS)) { - kfree(bitmap); - radix_tree_iter_delete(&ida->ida_rt, &iter, slot); - } - return; - err: - WARN(1, "ida_free called for id=%d which is not allocated.\n", id); -} - -/** - * ida_destroy() - Free all IDs. - * @ida: IDA handle. - * - * Calling this function frees all IDs and releases all resources used - * by an IDA. When this call returns, the IDA is empty and can be reused - * or freed. If the IDA is already empty, there is no need to call this - * function. - * - * Context: Any context. - */ -void ida_destroy(struct ida *ida) -{ - unsigned long flags; - struct radix_tree_iter iter; - void __rcu **slot; - - xa_lock_irqsave(&ida->ida_rt, flags); - radix_tree_for_each_slot(slot, &ida->ida_rt, &iter, 0) { - struct ida_bitmap *bitmap = rcu_dereference_raw(*slot); - if (!radix_tree_exception(bitmap)) - kfree(bitmap); - radix_tree_iter_delete(&ida->ida_rt, &iter, slot); - } - xa_unlock_irqrestore(&ida->ida_rt, flags); -} -EXPORT_SYMBOL(ida_destroy); - /** * ida_alloc_range() - Allocate an unused ID. * @ida: IDA handle. @@ -532,8 +377,10 @@ EXPORT_SYMBOL(ida_destroy); int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max, gfp_t gfp) { - int id = 0; + XA_STATE(xas, &ida->xa, min / IDA_BITMAP_BITS); + unsigned bit = min % IDA_BITMAP_BITS; unsigned long flags; + struct ida_bitmap *bitmap, *alloc = NULL; if ((int)min < 0) return -ENOSPC; @@ -541,22 +388,87 @@ int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max, if ((int)max < 0) max = INT_MAX; -again: - xa_lock_irqsave(&ida->ida_rt, flags); - id = ida_get_new_above(ida, min); - if (id > (int)max) { - ida_remove(ida, id); - id = -ENOSPC; - } - xa_unlock_irqrestore(&ida->ida_rt, flags); +retry: + xas_lock_irqsave(&xas, flags); +next: + bitmap = xas_find_marked(&xas, max / IDA_BITMAP_BITS, XA_FREE_MARK); + if (xas.xa_index > min / IDA_BITMAP_BITS) + bit = 0; + if (xas.xa_index * IDA_BITMAP_BITS + bit > max) + goto nospc; - if (unlikely(id == -EAGAIN)) { - if (!ida_pre_get(ida, gfp)) - return -ENOMEM; - goto again; + if (xa_is_value(bitmap)) { + unsigned long tmp = xa_to_value(bitmap); + + if (bit < BITS_PER_XA_VALUE) { + bit = find_next_zero_bit(&tmp, BITS_PER_XA_VALUE, bit); + if (xas.xa_index * IDA_BITMAP_BITS + bit > max) + goto nospc; + if (bit < BITS_PER_XA_VALUE) { + tmp |= 1UL << bit; + xas_store(&xas, xa_mk_value(tmp)); + goto out; + } + } + bitmap = alloc; + if (!bitmap) + bitmap = kzalloc(sizeof(*bitmap), GFP_NOWAIT); + if (!bitmap) + goto alloc; + bitmap->bitmap[0] = tmp; + xas_store(&xas, bitmap); + if (xas_error(&xas)) { + bitmap->bitmap[0] = 0; + goto out; + } } - return id; + if (bitmap) { + bit = find_next_zero_bit(bitmap->bitmap, IDA_BITMAP_BITS, bit); + if (xas.xa_index * IDA_BITMAP_BITS + bit > max) + goto nospc; + if (bit == IDA_BITMAP_BITS) + goto next; + + __set_bit(bit, bitmap->bitmap); + if (bitmap_full(bitmap->bitmap, IDA_BITMAP_BITS)) + xas_clear_mark(&xas, XA_FREE_MARK); + } else { + if (bit < BITS_PER_XA_VALUE) { + bitmap = xa_mk_value(1UL << bit); + } else { + bitmap = alloc; + if (!bitmap) + bitmap = kzalloc(sizeof(*bitmap), GFP_NOWAIT); + if (!bitmap) + goto alloc; + __set_bit(bit, bitmap->bitmap); + } + xas_store(&xas, bitmap); + } +out: + xas_unlock_irqrestore(&xas, flags); + if (xas_nomem(&xas, gfp)) { + xas.xa_index = min / IDA_BITMAP_BITS; + bit = min % IDA_BITMAP_BITS; + goto retry; + } + if (bitmap != alloc) + kfree(alloc); + if (xas_error(&xas)) + return xas_error(&xas); + return xas.xa_index * IDA_BITMAP_BITS + bit; +alloc: + xas_unlock_irqrestore(&xas, flags); + alloc = kzalloc(sizeof(*bitmap), gfp); + if (!alloc) + return -ENOMEM; + xas_set(&xas, min / IDA_BITMAP_BITS); + bit = min % IDA_BITMAP_BITS; + goto retry; +nospc: + xas_unlock_irqrestore(&xas, flags); + return -ENOSPC; } EXPORT_SYMBOL(ida_alloc_range); @@ -569,11 +481,112 @@ EXPORT_SYMBOL(ida_alloc_range); */ void ida_free(struct ida *ida, unsigned int id) { + XA_STATE(xas, &ida->xa, id / IDA_BITMAP_BITS); + unsigned bit = id % IDA_BITMAP_BITS; + struct ida_bitmap *bitmap; unsigned long flags; BUG_ON((int)id < 0); - xa_lock_irqsave(&ida->ida_rt, flags); - ida_remove(ida, id); - xa_unlock_irqrestore(&ida->ida_rt, flags); + + xas_lock_irqsave(&xas, flags); + bitmap = xas_load(&xas); + + if (xa_is_value(bitmap)) { + unsigned long v = xa_to_value(bitmap); + if (bit >= BITS_PER_XA_VALUE) + goto err; + if (!(v & (1UL << bit))) + goto err; + v &= ~(1UL << bit); + if (!v) + goto delete; + xas_store(&xas, xa_mk_value(v)); + } else { + if (!test_bit(bit, bitmap->bitmap)) + goto err; + __clear_bit(bit, bitmap->bitmap); + xas_set_mark(&xas, XA_FREE_MARK); + if (bitmap_empty(bitmap->bitmap, IDA_BITMAP_BITS)) { + kfree(bitmap); +delete: + xas_store(&xas, NULL); + } + } + xas_unlock_irqrestore(&xas, flags); + return; + err: + xas_unlock_irqrestore(&xas, flags); + WARN(1, "ida_free called for id=%d which is not allocated.\n", id); } EXPORT_SYMBOL(ida_free); + +/** + * ida_destroy() - Free all IDs. + * @ida: IDA handle. + * + * Calling this function frees all IDs and releases all resources used + * by an IDA. When this call returns, the IDA is empty and can be reused + * or freed. If the IDA is already empty, there is no need to call this + * function. + * + * Context: Any context. + */ +void ida_destroy(struct ida *ida) +{ + XA_STATE(xas, &ida->xa, 0); + struct ida_bitmap *bitmap; + unsigned long flags; + + xas_lock_irqsave(&xas, flags); + xas_for_each(&xas, bitmap, ULONG_MAX) { + if (!xa_is_value(bitmap)) + kfree(bitmap); + xas_store(&xas, NULL); + } + xas_unlock_irqrestore(&xas, flags); +} +EXPORT_SYMBOL(ida_destroy); + +#ifndef __KERNEL__ +extern void xa_dump_index(unsigned long index, unsigned int shift); +#define IDA_CHUNK_SHIFT ilog2(IDA_BITMAP_BITS) + +static void ida_dump_entry(void *entry, unsigned long index) +{ + unsigned long i; + + if (!entry) + return; + + if (xa_is_node(entry)) { + struct xa_node *node = xa_to_node(entry); + unsigned int shift = node->shift + IDA_CHUNK_SHIFT + + XA_CHUNK_SHIFT; + + xa_dump_index(index * IDA_BITMAP_BITS, shift); + xa_dump_node(node); + for (i = 0; i < XA_CHUNK_SIZE; i++) + ida_dump_entry(node->slots[i], + index | (i << node->shift)); + } else if (xa_is_value(entry)) { + xa_dump_index(index * IDA_BITMAP_BITS, ilog2(BITS_PER_LONG)); + pr_cont("value: data %lx [%px]\n", xa_to_value(entry), entry); + } else { + struct ida_bitmap *bitmap = entry; + + xa_dump_index(index * IDA_BITMAP_BITS, IDA_CHUNK_SHIFT); + pr_cont("bitmap: %p data", bitmap); + for (i = 0; i < IDA_BITMAP_LONGS; i++) + pr_cont(" %lx", bitmap->bitmap[i]); + pr_cont("\n"); + } +} + +static void ida_dump(struct ida *ida) +{ + struct xarray *xa = &ida->xa; + pr_debug("ida: %p node %p free %d\n", ida, xa->xa_head, + xa->xa_flags >> ROOT_TAG_SHIFT); + ida_dump_entry(xa->xa_head, 0); +} +#endif diff --git a/lib/radix-tree.c b/lib/radix-tree.c index bc03ecc4dfd2..1106bb6aa01e 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -38,15 +38,13 @@ #include #include #include +#include -/* Number of nodes in fully populated tree of given height */ -static unsigned long height_to_maxnodes[RADIX_TREE_MAX_PATH + 1] __read_mostly; - /* * Radix tree node cache. */ -static struct kmem_cache *radix_tree_node_cachep; +struct kmem_cache *radix_tree_node_cachep; /* * The radix tree is variable-height, so an insert operation not only has @@ -98,24 +96,7 @@ static inline void *node_to_entry(void *ptr) return (void *)((unsigned long)ptr | RADIX_TREE_INTERNAL_NODE); } -#define RADIX_TREE_RETRY node_to_entry(NULL) - -#ifdef CONFIG_RADIX_TREE_MULTIORDER -/* Sibling slots point directly to another slot in the same node */ -static inline -bool is_sibling_entry(const struct radix_tree_node *parent, void *node) -{ - void __rcu **ptr = node; - return (parent->slots <= ptr) && - (ptr < parent->slots + RADIX_TREE_MAP_SIZE); -} -#else -static inline -bool is_sibling_entry(const struct radix_tree_node *parent, void *node) -{ - return false; -} -#endif +#define RADIX_TREE_RETRY XA_RETRY_ENTRY static inline unsigned long get_slot_offset(const struct radix_tree_node *parent, void __rcu **slot) @@ -129,24 +110,13 @@ static unsigned int radix_tree_descend(const struct radix_tree_node *parent, unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK; void __rcu **entry = rcu_dereference_raw(parent->slots[offset]); -#ifdef CONFIG_RADIX_TREE_MULTIORDER - if (radix_tree_is_internal_node(entry)) { - if (is_sibling_entry(parent, entry)) { - void __rcu **sibentry; - sibentry = (void __rcu **) entry_to_node(entry); - offset = get_slot_offset(parent, sibentry); - entry = rcu_dereference_raw(*sibentry); - } - } -#endif - *nodep = (void *)entry; return offset; } static inline gfp_t root_gfp_mask(const struct radix_tree_root *root) { - return root->gfp_mask & (__GFP_BITS_MASK & ~GFP_ZONEMASK); + return root->xa_flags & (__GFP_BITS_MASK & ~GFP_ZONEMASK); } static inline void tag_set(struct radix_tree_node *node, unsigned int tag, @@ -169,32 +139,32 @@ static inline int tag_get(const struct radix_tree_node *node, unsigned int tag, static inline void root_tag_set(struct radix_tree_root *root, unsigned tag) { - root->gfp_mask |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT)); + root->xa_flags |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT)); } static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag) { - root->gfp_mask &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT)); + root->xa_flags &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT)); } static inline void root_tag_clear_all(struct radix_tree_root *root) { - root->gfp_mask &= (1 << ROOT_TAG_SHIFT) - 1; + root->xa_flags &= (__force gfp_t)((1 << ROOT_TAG_SHIFT) - 1); } static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag) { - return (__force int)root->gfp_mask & (1 << (tag + ROOT_TAG_SHIFT)); + return (__force int)root->xa_flags & (1 << (tag + ROOT_TAG_SHIFT)); } static inline unsigned root_tags_get(const struct radix_tree_root *root) { - return (__force unsigned)root->gfp_mask >> ROOT_TAG_SHIFT; + return (__force unsigned)root->xa_flags >> ROOT_TAG_SHIFT; } static inline bool is_idr(const struct radix_tree_root *root) { - return !!(root->gfp_mask & ROOT_IS_IDR); + return !!(root->xa_flags & ROOT_IS_IDR); } /* @@ -254,7 +224,7 @@ radix_tree_find_next_bit(struct radix_tree_node *node, unsigned int tag, static unsigned int iter_offset(const struct radix_tree_iter *iter) { - return (iter->index >> iter_shift(iter)) & RADIX_TREE_MAP_MASK; + return iter->index & RADIX_TREE_MAP_MASK; } /* @@ -277,99 +247,6 @@ static unsigned long next_index(unsigned long index, return (index & ~node_maxindex(node)) + (offset << node->shift); } -#ifndef __KERNEL__ -static void dump_node(struct radix_tree_node *node, unsigned long index) -{ - unsigned long i; - - pr_debug("radix node: %p offset %d indices %lu-%lu parent %p tags %lx %lx %lx shift %d count %d exceptional %d\n", - node, node->offset, index, index | node_maxindex(node), - node->parent, - node->tags[0][0], node->tags[1][0], node->tags[2][0], - node->shift, node->count, node->exceptional); - - for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) { - unsigned long first = index | (i << node->shift); - unsigned long last = first | ((1UL << node->shift) - 1); - void *entry = node->slots[i]; - if (!entry) - continue; - if (entry == RADIX_TREE_RETRY) { - pr_debug("radix retry offset %ld indices %lu-%lu parent %p\n", - i, first, last, node); - } else if (!radix_tree_is_internal_node(entry)) { - pr_debug("radix entry %p offset %ld indices %lu-%lu parent %p\n", - entry, i, first, last, node); - } else if (is_sibling_entry(node, entry)) { - pr_debug("radix sblng %p offset %ld indices %lu-%lu parent %p val %p\n", - entry, i, first, last, node, - *(void **)entry_to_node(entry)); - } else { - dump_node(entry_to_node(entry), first); - } - } -} - -/* For debug */ -static void radix_tree_dump(struct radix_tree_root *root) -{ - pr_debug("radix root: %p rnode %p tags %x\n", - root, root->rnode, - root->gfp_mask >> ROOT_TAG_SHIFT); - if (!radix_tree_is_internal_node(root->rnode)) - return; - dump_node(entry_to_node(root->rnode), 0); -} - -static void dump_ida_node(void *entry, unsigned long index) -{ - unsigned long i; - - if (!entry) - return; - - if (radix_tree_is_internal_node(entry)) { - struct radix_tree_node *node = entry_to_node(entry); - - pr_debug("ida node: %p offset %d indices %lu-%lu parent %p free %lx shift %d count %d\n", - node, node->offset, index * IDA_BITMAP_BITS, - ((index | node_maxindex(node)) + 1) * - IDA_BITMAP_BITS - 1, - node->parent, node->tags[0][0], node->shift, - node->count); - for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) - dump_ida_node(node->slots[i], - index | (i << node->shift)); - } else if (radix_tree_exceptional_entry(entry)) { - pr_debug("ida excp: %p offset %d indices %lu-%lu data %lx\n", - entry, (int)(index & RADIX_TREE_MAP_MASK), - index * IDA_BITMAP_BITS, - index * IDA_BITMAP_BITS + BITS_PER_LONG - - RADIX_TREE_EXCEPTIONAL_SHIFT, - (unsigned long)entry >> - RADIX_TREE_EXCEPTIONAL_SHIFT); - } else { - struct ida_bitmap *bitmap = entry; - - pr_debug("ida btmp: %p offset %d indices %lu-%lu data", bitmap, - (int)(index & RADIX_TREE_MAP_MASK), - index * IDA_BITMAP_BITS, - (index + 1) * IDA_BITMAP_BITS - 1); - for (i = 0; i < IDA_BITMAP_LONGS; i++) - pr_cont(" %lx", bitmap->bitmap[i]); - pr_cont("\n"); - } -} - -static void ida_dump(struct ida *ida) -{ - struct radix_tree_root *root = &ida->ida_rt; - pr_debug("ida: %p node %p free %d\n", ida, root->rnode, - root->gfp_mask >> ROOT_TAG_SHIFT); - dump_ida_node(root->rnode, 0); -} -#endif - /* * This assumes that the caller has performed appropriate preallocation, and * that the caller has pinned this thread of control to the current CPU. @@ -378,7 +255,7 @@ static struct radix_tree_node * radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent, struct radix_tree_root *root, unsigned int shift, unsigned int offset, - unsigned int count, unsigned int exceptional) + unsigned int count, unsigned int nr_values) { struct radix_tree_node *ret = NULL; @@ -425,14 +302,14 @@ out: ret->shift = shift; ret->offset = offset; ret->count = count; - ret->exceptional = exceptional; + ret->nr_values = nr_values; ret->parent = parent; - ret->root = root; + ret->array = root; } return ret; } -static void radix_tree_node_rcu_free(struct rcu_head *head) +void radix_tree_node_rcu_free(struct rcu_head *head) { struct radix_tree_node *node = container_of(head, struct radix_tree_node, rcu_head); @@ -530,77 +407,10 @@ int radix_tree_maybe_preload(gfp_t gfp_mask) } EXPORT_SYMBOL(radix_tree_maybe_preload); -#ifdef CONFIG_RADIX_TREE_MULTIORDER -/* - * Preload with enough objects to ensure that we can split a single entry - * of order @old_order into many entries of size @new_order - */ -int radix_tree_split_preload(unsigned int old_order, unsigned int new_order, - gfp_t gfp_mask) -{ - unsigned top = 1 << (old_order % RADIX_TREE_MAP_SHIFT); - unsigned layers = (old_order / RADIX_TREE_MAP_SHIFT) - - (new_order / RADIX_TREE_MAP_SHIFT); - unsigned nr = 0; - - WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask)); - BUG_ON(new_order >= old_order); - - while (layers--) - nr = nr * RADIX_TREE_MAP_SIZE + 1; - return __radix_tree_preload(gfp_mask, top * nr); -} -#endif - -/* - * The same as function above, but preload number of nodes required to insert - * (1 << order) continuous naturally-aligned elements. - */ -int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order) -{ - unsigned long nr_subtrees; - int nr_nodes, subtree_height; - - /* Preloading doesn't help anything with this gfp mask, skip it */ - if (!gfpflags_allow_blocking(gfp_mask)) { - preempt_disable(); - return 0; - } - - /* - * Calculate number and height of fully populated subtrees it takes to - * store (1 << order) elements. - */ - nr_subtrees = 1 << order; - for (subtree_height = 0; nr_subtrees > RADIX_TREE_MAP_SIZE; - subtree_height++) - nr_subtrees >>= RADIX_TREE_MAP_SHIFT; - - /* - * The worst case is zero height tree with a single item at index 0 and - * then inserting items starting at ULONG_MAX - (1 << order). - * - * This requires RADIX_TREE_MAX_PATH nodes to build branch from root to - * 0-index item. - */ - nr_nodes = RADIX_TREE_MAX_PATH; - - /* Plus branch to fully populated subtrees. */ - nr_nodes += RADIX_TREE_MAX_PATH - subtree_height; - - /* Root node is shared. */ - nr_nodes--; - - /* Plus nodes required to build subtrees. */ - nr_nodes += nr_subtrees * height_to_maxnodes[subtree_height]; - - return __radix_tree_preload(gfp_mask, nr_nodes); -} - static unsigned radix_tree_load_root(const struct radix_tree_root *root, struct radix_tree_node **nodep, unsigned long *maxindex) { - struct radix_tree_node *node = rcu_dereference_raw(root->rnode); + struct radix_tree_node *node = rcu_dereference_raw(root->xa_head); *nodep = node; @@ -629,7 +439,7 @@ static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp, while (index > shift_maxindex(maxshift)) maxshift += RADIX_TREE_MAP_SHIFT; - entry = rcu_dereference_raw(root->rnode); + entry = rcu_dereference_raw(root->xa_head); if (!entry && (!is_idr(root) || root_tag_get(root, IDR_FREE))) goto out; @@ -656,9 +466,9 @@ static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp, BUG_ON(shift > BITS_PER_LONG); if (radix_tree_is_internal_node(entry)) { entry_to_node(entry)->parent = node; - } else if (radix_tree_exceptional_entry(entry)) { - /* Moving an exceptional root->rnode to a node */ - node->exceptional = 1; + } else if (xa_is_value(entry)) { + /* Moving a value entry root->xa_head to a node */ + node->nr_values = 1; } /* * entry was already in the radix tree, so we do not need @@ -666,7 +476,7 @@ static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp, */ node->slots[0] = (void __rcu *)entry; entry = node_to_entry(node); - rcu_assign_pointer(root->rnode, entry); + rcu_assign_pointer(root->xa_head, entry); shift += RADIX_TREE_MAP_SHIFT; } while (shift <= maxshift); out: @@ -677,13 +487,12 @@ out: * radix_tree_shrink - shrink radix tree to minimum height * @root radix tree root */ -static inline bool radix_tree_shrink(struct radix_tree_root *root, - radix_tree_update_node_t update_node) +static inline bool radix_tree_shrink(struct radix_tree_root *root) { bool shrunk = false; for (;;) { - struct radix_tree_node *node = rcu_dereference_raw(root->rnode); + struct radix_tree_node *node = rcu_dereference_raw(root->xa_head); struct radix_tree_node *child; if (!radix_tree_is_internal_node(node)) @@ -692,15 +501,20 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root, /* * The candidate node has more than one child, or its child - * is not at the leftmost slot, or the child is a multiorder - * entry, we cannot shrink. + * is not at the leftmost slot, we cannot shrink. */ if (node->count != 1) break; child = rcu_dereference_raw(node->slots[0]); if (!child) break; - if (!radix_tree_is_internal_node(child) && node->shift) + + /* + * For an IDR, we must not shrink entry 0 into the root in + * case somebody calls idr_replace() with a pointer that + * appears to be an internal entry + */ + if (!node->shift && is_idr(root)) break; if (radix_tree_is_internal_node(child)) @@ -711,9 +525,9 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root, * moving the node from one part of the tree to another: if it * was safe to dereference the old pointer to it * (node->slots[0]), it will be safe to dereference the new - * one (root->rnode) as far as dependent read barriers go. + * one (root->xa_head) as far as dependent read barriers go. */ - root->rnode = (void __rcu *)child; + root->xa_head = (void __rcu *)child; if (is_idr(root) && !tag_get(node, IDR_FREE, 0)) root_tag_clear(root, IDR_FREE); @@ -738,8 +552,6 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root, node->count = 0; if (!radix_tree_is_internal_node(child)) { node->slots[0] = (void __rcu *)RADIX_TREE_RETRY; - if (update_node) - update_node(node); } WARN_ON_ONCE(!list_empty(&node->private_list)); @@ -751,8 +563,7 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root, } static bool delete_node(struct radix_tree_root *root, - struct radix_tree_node *node, - radix_tree_update_node_t update_node) + struct radix_tree_node *node) { bool deleted = false; @@ -761,9 +572,8 @@ static bool delete_node(struct radix_tree_root *root, if (node->count) { if (node_to_entry(node) == - rcu_dereference_raw(root->rnode)) - deleted |= radix_tree_shrink(root, - update_node); + rcu_dereference_raw(root->xa_head)) + deleted |= radix_tree_shrink(root); return deleted; } @@ -778,7 +588,7 @@ static bool delete_node(struct radix_tree_root *root, */ if (!is_idr(root)) root_tag_clear_all(root); - root->rnode = NULL; + root->xa_head = NULL; } WARN_ON_ONCE(!list_empty(&node->private_list)); @@ -795,7 +605,6 @@ static bool delete_node(struct radix_tree_root *root, * __radix_tree_create - create a slot in a radix tree * @root: radix tree root * @index: index key - * @order: index occupies 2^order aligned slots * @nodep: returns node * @slotp: returns slot * @@ -803,36 +612,34 @@ static bool delete_node(struct radix_tree_root *root, * at position @index in the radix tree @root. * * Until there is more than one item in the tree, no nodes are - * allocated and @root->rnode is used as a direct slot instead of + * allocated and @root->xa_head is used as a direct slot instead of * pointing to a node, in which case *@nodep will be NULL. * * Returns -ENOMEM, or 0 for success. */ -int __radix_tree_create(struct radix_tree_root *root, unsigned long index, - unsigned order, struct radix_tree_node **nodep, - void __rcu ***slotp) +static int __radix_tree_create(struct radix_tree_root *root, + unsigned long index, struct radix_tree_node **nodep, + void __rcu ***slotp) { struct radix_tree_node *node = NULL, *child; - void __rcu **slot = (void __rcu **)&root->rnode; + void __rcu **slot = (void __rcu **)&root->xa_head; unsigned long maxindex; unsigned int shift, offset = 0; - unsigned long max = index | ((1UL << order) - 1); + unsigned long max = index; gfp_t gfp = root_gfp_mask(root); shift = radix_tree_load_root(root, &child, &maxindex); /* Make sure the tree is high enough. */ - if (order > 0 && max == ((1UL << order) - 1)) - max++; if (max > maxindex) { int error = radix_tree_extend(root, gfp, max, shift); if (error < 0) return error; shift = error; - child = rcu_dereference_raw(root->rnode); + child = rcu_dereference_raw(root->xa_head); } - while (shift > order) { + while (shift > 0) { shift -= RADIX_TREE_MAP_SHIFT; if (child == NULL) { /* Have to add a child node. */ @@ -875,8 +682,7 @@ static void radix_tree_free_nodes(struct radix_tree_node *node) for (;;) { void *entry = rcu_dereference_raw(child->slots[offset]); - if (radix_tree_is_internal_node(entry) && - !is_sibling_entry(child, entry)) { + if (xa_is_node(entry) && child->shift) { child = entry_to_node(entry); offset = 0; continue; @@ -894,96 +700,30 @@ static void radix_tree_free_nodes(struct radix_tree_node *node) } } -#ifdef CONFIG_RADIX_TREE_MULTIORDER static inline int insert_entries(struct radix_tree_node *node, - void __rcu **slot, void *item, unsigned order, bool replace) -{ - struct radix_tree_node *child; - unsigned i, n, tag, offset, tags = 0; - - if (node) { - if (order > node->shift) - n = 1 << (order - node->shift); - else - n = 1; - offset = get_slot_offset(node, slot); - } else { - n = 1; - offset = 0; - } - - if (n > 1) { - offset = offset & ~(n - 1); - slot = &node->slots[offset]; - } - child = node_to_entry(slot); - - for (i = 0; i < n; i++) { - if (slot[i]) { - if (replace) { - node->count--; - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - if (tag_get(node, tag, offset + i)) - tags |= 1 << tag; - } else - return -EEXIST; - } - } - - for (i = 0; i < n; i++) { - struct radix_tree_node *old = rcu_dereference_raw(slot[i]); - if (i) { - rcu_assign_pointer(slot[i], child); - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - if (tags & (1 << tag)) - tag_clear(node, tag, offset + i); - } else { - rcu_assign_pointer(slot[i], item); - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - if (tags & (1 << tag)) - tag_set(node, tag, offset); - } - if (radix_tree_is_internal_node(old) && - !is_sibling_entry(node, old) && - (old != RADIX_TREE_RETRY)) - radix_tree_free_nodes(old); - if (radix_tree_exceptional_entry(old)) - node->exceptional--; - } - if (node) { - node->count += n; - if (radix_tree_exceptional_entry(item)) - node->exceptional += n; - } - return n; -} -#else -static inline int insert_entries(struct radix_tree_node *node, - void __rcu **slot, void *item, unsigned order, bool replace) + void __rcu **slot, void *item, bool replace) { if (*slot) return -EEXIST; rcu_assign_pointer(*slot, item); if (node) { node->count++; - if (radix_tree_exceptional_entry(item)) - node->exceptional++; + if (xa_is_value(item)) + node->nr_values++; } return 1; } -#endif /** * __radix_tree_insert - insert into a radix tree * @root: radix tree root * @index: index key - * @order: key covers the 2^order indices around index * @item: item to insert * * Insert an item into the radix tree at position @index. */ -int __radix_tree_insert(struct radix_tree_root *root, unsigned long index, - unsigned order, void *item) +int radix_tree_insert(struct radix_tree_root *root, unsigned long index, + void *item) { struct radix_tree_node *node; void __rcu **slot; @@ -991,11 +731,11 @@ int __radix_tree_insert(struct radix_tree_root *root, unsigned long index, BUG_ON(radix_tree_is_internal_node(item)); - error = __radix_tree_create(root, index, order, &node, &slot); + error = __radix_tree_create(root, index, &node, &slot); if (error) return error; - error = insert_entries(node, slot, item, order, false); + error = insert_entries(node, slot, item, false); if (error < 0) return error; @@ -1010,7 +750,7 @@ int __radix_tree_insert(struct radix_tree_root *root, unsigned long index, return 0; } -EXPORT_SYMBOL(__radix_tree_insert); +EXPORT_SYMBOL(radix_tree_insert); /** * __radix_tree_lookup - lookup an item in a radix tree @@ -1023,7 +763,7 @@ EXPORT_SYMBOL(__radix_tree_insert); * tree @root. * * Until there is more than one item in the tree, no nodes are - * allocated and @root->rnode is used as a direct slot instead of + * allocated and @root->xa_head is used as a direct slot instead of * pointing to a node, in which case *@nodep will be NULL. */ void *__radix_tree_lookup(const struct radix_tree_root *root, @@ -1036,7 +776,7 @@ void *__radix_tree_lookup(const struct radix_tree_root *root, restart: parent = NULL; - slot = (void __rcu **)&root->rnode; + slot = (void __rcu **)&root->xa_head; radix_tree_load_root(root, &node, &maxindex); if (index > maxindex) return NULL; @@ -1049,6 +789,8 @@ void *__radix_tree_lookup(const struct radix_tree_root *root, parent = entry_to_node(node); offset = radix_tree_descend(parent, &node, index); slot = parent->slots + offset; + if (parent->shift == 0) + break; } if (nodep) @@ -1100,36 +842,12 @@ void *radix_tree_lookup(const struct radix_tree_root *root, unsigned long index) } EXPORT_SYMBOL(radix_tree_lookup); -static inline void replace_sibling_entries(struct radix_tree_node *node, - void __rcu **slot, int count, int exceptional) -{ -#ifdef CONFIG_RADIX_TREE_MULTIORDER - void *ptr = node_to_entry(slot); - unsigned offset = get_slot_offset(node, slot) + 1; - - while (offset < RADIX_TREE_MAP_SIZE) { - if (rcu_dereference_raw(node->slots[offset]) != ptr) - break; - if (count < 0) { - node->slots[offset] = NULL; - node->count--; - } - node->exceptional += exceptional; - offset++; - } -#endif -} - static void replace_slot(void __rcu **slot, void *item, - struct radix_tree_node *node, int count, int exceptional) + struct radix_tree_node *node, int count, int values) { - if (WARN_ON_ONCE(radix_tree_is_internal_node(item))) - return; - - if (node && (count || exceptional)) { + if (node && (count || values)) { node->count += count; - node->exceptional += exceptional; - replace_sibling_entries(node, slot, count, exceptional); + node->nr_values += values; } rcu_assign_pointer(*slot, item); @@ -1172,37 +890,31 @@ static int calculate_count(struct radix_tree_root *root, * @node: pointer to tree node * @slot: pointer to slot in @node * @item: new item to store in the slot. - * @update_node: callback for changing leaf nodes * * For use with __radix_tree_lookup(). Caller must hold tree write locked * across slot lookup and replacement. */ void __radix_tree_replace(struct radix_tree_root *root, struct radix_tree_node *node, - void __rcu **slot, void *item, - radix_tree_update_node_t update_node) + void __rcu **slot, void *item) { void *old = rcu_dereference_raw(*slot); - int exceptional = !!radix_tree_exceptional_entry(item) - - !!radix_tree_exceptional_entry(old); + int values = !!xa_is_value(item) - !!xa_is_value(old); int count = calculate_count(root, node, slot, item, old); /* - * This function supports replacing exceptional entries and + * This function supports replacing value entries and * deleting entries, but that needs accounting against the - * node unless the slot is root->rnode. + * node unless the slot is root->xa_head. */ - WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->rnode) && - (count || exceptional)); - replace_slot(slot, item, node, count, exceptional); + WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->xa_head) && + (count || values)); + replace_slot(slot, item, node, count, values); if (!node) return; - if (update_node) - update_node(node); - - delete_node(root, node, update_node); + delete_node(root, node); } /** @@ -1211,12 +923,12 @@ void __radix_tree_replace(struct radix_tree_root *root, * @slot: pointer to slot * @item: new item to store in the slot. * - * For use with radix_tree_lookup_slot(), radix_tree_gang_lookup_slot(), + * For use with radix_tree_lookup_slot() and * radix_tree_gang_lookup_tag_slot(). Caller must hold tree write locked * across slot lookup and replacement. * * NOTE: This cannot be used to switch between non-entries (empty slots), - * regular entries, and exceptional entries, as that requires accounting + * regular entries, and value entries, as that requires accounting * inside the radix tree node. When switching from one type of entry or * deleting, use __radix_tree_lookup() and __radix_tree_replace() or * radix_tree_iter_replace(). @@ -1224,7 +936,7 @@ void __radix_tree_replace(struct radix_tree_root *root, void radix_tree_replace_slot(struct radix_tree_root *root, void __rcu **slot, void *item) { - __radix_tree_replace(root, NULL, slot, item, NULL); + __radix_tree_replace(root, NULL, slot, item); } EXPORT_SYMBOL(radix_tree_replace_slot); @@ -1234,162 +946,16 @@ EXPORT_SYMBOL(radix_tree_replace_slot); * @slot: pointer to slot * @item: new item to store in the slot. * - * For use with radix_tree_split() and radix_tree_for_each_slot(). - * Caller must hold tree write locked across split and replacement. + * For use with radix_tree_for_each_slot(). + * Caller must hold tree write locked. */ void radix_tree_iter_replace(struct radix_tree_root *root, const struct radix_tree_iter *iter, void __rcu **slot, void *item) { - __radix_tree_replace(root, iter->node, slot, item, NULL); + __radix_tree_replace(root, iter->node, slot, item); } -#ifdef CONFIG_RADIX_TREE_MULTIORDER -/** - * radix_tree_join - replace multiple entries with one multiorder entry - * @root: radix tree root - * @index: an index inside the new entry - * @order: order of the new entry - * @item: new entry - * - * Call this function to replace several entries with one larger entry. - * The existing entries are presumed to not need freeing as a result of - * this call. - * - * The replacement entry will have all the tags set on it that were set - * on any of the entries it is replacing. - */ -int radix_tree_join(struct radix_tree_root *root, unsigned long index, - unsigned order, void *item) -{ - struct radix_tree_node *node; - void __rcu **slot; - int error; - - BUG_ON(radix_tree_is_internal_node(item)); - - error = __radix_tree_create(root, index, order, &node, &slot); - if (!error) - error = insert_entries(node, slot, item, order, true); - if (error > 0) - error = 0; - - return error; -} - -/** - * radix_tree_split - Split an entry into smaller entries - * @root: radix tree root - * @index: An index within the large entry - * @order: Order of new entries - * - * Call this function as the first step in replacing a multiorder entry - * with several entries of lower order. After this function returns, - * loop over the relevant portion of the tree using radix_tree_for_each_slot() - * and call radix_tree_iter_replace() to set up each new entry. - * - * The tags from this entry are replicated to all the new entries. - * - * The radix tree should be locked against modification during the entire - * replacement operation. Lock-free lookups will see RADIX_TREE_RETRY which - * should prompt RCU walkers to restart the lookup from the root. - */ -int radix_tree_split(struct radix_tree_root *root, unsigned long index, - unsigned order) -{ - struct radix_tree_node *parent, *node, *child; - void __rcu **slot; - unsigned int offset, end; - unsigned n, tag, tags = 0; - gfp_t gfp = root_gfp_mask(root); - - if (!__radix_tree_lookup(root, index, &parent, &slot)) - return -ENOENT; - if (!parent) - return -ENOENT; - - offset = get_slot_offset(parent, slot); - - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - if (tag_get(parent, tag, offset)) - tags |= 1 << tag; - - for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) { - if (!is_sibling_entry(parent, - rcu_dereference_raw(parent->slots[end]))) - break; - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - if (tags & (1 << tag)) - tag_set(parent, tag, end); - /* rcu_assign_pointer ensures tags are set before RETRY */ - rcu_assign_pointer(parent->slots[end], RADIX_TREE_RETRY); - } - rcu_assign_pointer(parent->slots[offset], RADIX_TREE_RETRY); - parent->exceptional -= (end - offset); - - if (order == parent->shift) - return 0; - if (order > parent->shift) { - while (offset < end) - offset += insert_entries(parent, &parent->slots[offset], - RADIX_TREE_RETRY, order, true); - return 0; - } - - node = parent; - - for (;;) { - if (node->shift > order) { - child = radix_tree_node_alloc(gfp, node, root, - node->shift - RADIX_TREE_MAP_SHIFT, - offset, 0, 0); - if (!child) - goto nomem; - if (node != parent) { - node->count++; - rcu_assign_pointer(node->slots[offset], - node_to_entry(child)); - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - if (tags & (1 << tag)) - tag_set(node, tag, offset); - } - - node = child; - offset = 0; - continue; - } - - n = insert_entries(node, &node->slots[offset], - RADIX_TREE_RETRY, order, false); - BUG_ON(n > RADIX_TREE_MAP_SIZE); - - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - if (tags & (1 << tag)) - tag_set(node, tag, offset); - offset += n; - - while (offset == RADIX_TREE_MAP_SIZE) { - if (node == parent) - break; - offset = node->offset; - child = node; - node = node->parent; - rcu_assign_pointer(node->slots[offset], - node_to_entry(child)); - offset++; - } - if ((node == parent) && (offset == end)) - return 0; - } - - nomem: - /* Shouldn't happen; did user forget to preload? */ - /* TODO: free all the allocated nodes */ - WARN_ON(1); - return -ENOMEM; -} -#endif - static void node_tag_set(struct radix_tree_root *root, struct radix_tree_node *node, unsigned int tag, unsigned int offset) @@ -1447,18 +1013,6 @@ void *radix_tree_tag_set(struct radix_tree_root *root, } EXPORT_SYMBOL(radix_tree_tag_set); -/** - * radix_tree_iter_tag_set - set a tag on the current iterator entry - * @root: radix tree root - * @iter: iterator state - * @tag: tag to set - */ -void radix_tree_iter_tag_set(struct radix_tree_root *root, - const struct radix_tree_iter *iter, unsigned int tag) -{ - node_tag_set(root, iter->node, tag, iter_offset(iter)); -} - static void node_tag_clear(struct radix_tree_root *root, struct radix_tree_node *node, unsigned int tag, unsigned int offset) @@ -1574,14 +1128,6 @@ int radix_tree_tag_get(const struct radix_tree_root *root, } EXPORT_SYMBOL(radix_tree_tag_get); -static inline void __set_iter_shift(struct radix_tree_iter *iter, - unsigned int shift) -{ -#ifdef CONFIG_RADIX_TREE_MULTIORDER - iter->shift = shift; -#endif -} - /* Construct iter->tags bit-mask from node->tags[tag] array */ static void set_iter_tags(struct radix_tree_iter *iter, struct radix_tree_node *node, unsigned offset, @@ -1608,92 +1154,11 @@ static void set_iter_tags(struct radix_tree_iter *iter, } } -#ifdef CONFIG_RADIX_TREE_MULTIORDER -static void __rcu **skip_siblings(struct radix_tree_node **nodep, - void __rcu **slot, struct radix_tree_iter *iter) -{ - while (iter->index < iter->next_index) { - *nodep = rcu_dereference_raw(*slot); - if (*nodep && !is_sibling_entry(iter->node, *nodep)) - return slot; - slot++; - iter->index = __radix_tree_iter_add(iter, 1); - iter->tags >>= 1; - } - - *nodep = NULL; - return NULL; -} - -void __rcu **__radix_tree_next_slot(void __rcu **slot, - struct radix_tree_iter *iter, unsigned flags) -{ - unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; - struct radix_tree_node *node; - - slot = skip_siblings(&node, slot, iter); - - while (radix_tree_is_internal_node(node)) { - unsigned offset; - unsigned long next_index; - - if (node == RADIX_TREE_RETRY) - return slot; - node = entry_to_node(node); - iter->node = node; - iter->shift = node->shift; - - if (flags & RADIX_TREE_ITER_TAGGED) { - offset = radix_tree_find_next_bit(node, tag, 0); - if (offset == RADIX_TREE_MAP_SIZE) - return NULL; - slot = &node->slots[offset]; - iter->index = __radix_tree_iter_add(iter, offset); - set_iter_tags(iter, node, offset, tag); - node = rcu_dereference_raw(*slot); - } else { - offset = 0; - slot = &node->slots[0]; - for (;;) { - node = rcu_dereference_raw(*slot); - if (node) - break; - slot++; - offset++; - if (offset == RADIX_TREE_MAP_SIZE) - return NULL; - } - iter->index = __radix_tree_iter_add(iter, offset); - } - if ((flags & RADIX_TREE_ITER_CONTIG) && (offset > 0)) - goto none; - next_index = (iter->index | shift_maxindex(iter->shift)) + 1; - if (next_index < iter->next_index) - iter->next_index = next_index; - } - - return slot; - none: - iter->next_index = 0; - return NULL; -} -EXPORT_SYMBOL(__radix_tree_next_slot); -#else -static void __rcu **skip_siblings(struct radix_tree_node **nodep, - void __rcu **slot, struct radix_tree_iter *iter) -{ - return slot; -} -#endif - void __rcu **radix_tree_iter_resume(void __rcu **slot, struct radix_tree_iter *iter) { - struct radix_tree_node *node; - slot++; iter->index = __radix_tree_iter_add(iter, 1); - skip_siblings(&node, slot, iter); iter->next_index = iter->index; iter->tags = 0; return NULL; @@ -1744,8 +1209,7 @@ void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root, iter->next_index = maxindex + 1; iter->tags = 1; iter->node = NULL; - __set_iter_shift(iter, 0); - return (void __rcu **)&root->rnode; + return (void __rcu **)&root->xa_head; } do { @@ -1765,8 +1229,6 @@ void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root, while (++offset < RADIX_TREE_MAP_SIZE) { void *slot = rcu_dereference_raw( node->slots[offset]); - if (is_sibling_entry(node, slot)) - continue; if (slot) break; } @@ -1784,13 +1246,12 @@ void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root, goto restart; if (child == RADIX_TREE_RETRY) break; - } while (radix_tree_is_internal_node(child)); + } while (node->shift && radix_tree_is_internal_node(child)); /* Update the iterator state */ - iter->index = (index &~ node_maxindex(node)) | (offset << node->shift); + iter->index = (index &~ node_maxindex(node)) | offset; iter->next_index = (index | node_maxindex(node)) + 1; iter->node = node; - __set_iter_shift(iter, node->shift); if (flags & RADIX_TREE_ITER_TAGGED) set_iter_tags(iter, node, offset, tag); @@ -1846,48 +1307,6 @@ radix_tree_gang_lookup(const struct radix_tree_root *root, void **results, } EXPORT_SYMBOL(radix_tree_gang_lookup); -/** - * radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree - * @root: radix tree root - * @results: where the results of the lookup are placed - * @indices: where their indices should be placed (but usually NULL) - * @first_index: start the lookup from this key - * @max_items: place up to this many items at *results - * - * Performs an index-ascending scan of the tree for present items. Places - * their slots at *@results and returns the number of items which were - * placed at *@results. - * - * The implementation is naive. - * - * Like radix_tree_gang_lookup as far as RCU and locking goes. Slots must - * be dereferenced with radix_tree_deref_slot, and if using only RCU - * protection, radix_tree_deref_slot may fail requiring a retry. - */ -unsigned int -radix_tree_gang_lookup_slot(const struct radix_tree_root *root, - void __rcu ***results, unsigned long *indices, - unsigned long first_index, unsigned int max_items) -{ - struct radix_tree_iter iter; - void __rcu **slot; - unsigned int ret = 0; - - if (unlikely(!max_items)) - return 0; - - radix_tree_for_each_slot(slot, root, &iter, first_index) { - results[ret] = slot; - if (indices) - indices[ret] = iter.index; - if (++ret == max_items) - break; - } - - return ret; -} -EXPORT_SYMBOL(radix_tree_gang_lookup_slot); - /** * radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree * based on a tag @@ -1964,28 +1383,11 @@ radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root, } EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot); -/** - * __radix_tree_delete_node - try to free node after clearing a slot - * @root: radix tree root - * @node: node containing @index - * @update_node: callback for changing leaf nodes - * - * After clearing the slot at @index in @node from radix tree - * rooted at @root, call this function to attempt freeing the - * node and shrinking the tree. - */ -void __radix_tree_delete_node(struct radix_tree_root *root, - struct radix_tree_node *node, - radix_tree_update_node_t update_node) -{ - delete_node(root, node, update_node); -} - static bool __radix_tree_delete(struct radix_tree_root *root, struct radix_tree_node *node, void __rcu **slot) { void *old = rcu_dereference_raw(*slot); - int exceptional = radix_tree_exceptional_entry(old) ? -1 : 0; + int values = xa_is_value(old) ? -1 : 0; unsigned offset = get_slot_offset(node, slot); int tag; @@ -1995,8 +1397,8 @@ static bool __radix_tree_delete(struct radix_tree_root *root, for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) node_tag_clear(root, node, tag, offset); - replace_slot(slot, NULL, node, -1, exceptional); - return node && delete_node(root, node, NULL); + replace_slot(slot, NULL, node, -1, values); + return node && delete_node(root, node); } /** @@ -2068,19 +1470,6 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) } EXPORT_SYMBOL(radix_tree_delete); -void radix_tree_clear_tags(struct radix_tree_root *root, - struct radix_tree_node *node, - void __rcu **slot) -{ - if (node) { - unsigned int tag, offset = get_slot_offset(node, slot); - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - node_tag_clear(root, node, tag, offset); - } else { - root_tag_clear_all(root); - } -} - /** * radix_tree_tagged - test whether any items in the tree are tagged * @root: radix tree root @@ -2106,33 +1495,12 @@ void idr_preload(gfp_t gfp_mask) } EXPORT_SYMBOL(idr_preload); -int ida_pre_get(struct ida *ida, gfp_t gfp) -{ - /* - * The IDA API has no preload_end() equivalent. Instead, - * ida_get_new() can return -EAGAIN, prompting the caller - * to return to the ida_pre_get() step. - */ - if (!__radix_tree_preload(gfp, IDA_PRELOAD_SIZE)) - preempt_enable(); - - if (!this_cpu_read(ida_bitmap)) { - struct ida_bitmap *bitmap = kzalloc(sizeof(*bitmap), gfp); - if (!bitmap) - return 0; - if (this_cpu_cmpxchg(ida_bitmap, NULL, bitmap)) - kfree(bitmap); - } - - return 1; -} - void __rcu **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, unsigned long max) { struct radix_tree_node *node = NULL, *child; - void __rcu **slot = (void __rcu **)&root->rnode; + void __rcu **slot = (void __rcu **)&root->xa_head; unsigned long maxindex, start = iter->next_index; unsigned int shift, offset = 0; @@ -2148,8 +1516,10 @@ void __rcu **idr_get_free(struct radix_tree_root *root, if (error < 0) return ERR_PTR(error); shift = error; - child = rcu_dereference_raw(root->rnode); + child = rcu_dereference_raw(root->xa_head); } + if (start == 0 && shift == 0) + shift = RADIX_TREE_MAP_SHIFT; while (shift) { shift -= RADIX_TREE_MAP_SHIFT; @@ -2192,7 +1562,6 @@ void __rcu **idr_get_free(struct radix_tree_root *root, else iter->next_index = 1; iter->node = node; - __set_iter_shift(iter, shift); set_iter_tags(iter, node, offset, IDR_FREE); return slot; @@ -2211,10 +1580,10 @@ void __rcu **idr_get_free(struct radix_tree_root *root, */ void idr_destroy(struct idr *idr) { - struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.rnode); + struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.xa_head); if (radix_tree_is_internal_node(node)) radix_tree_free_nodes(node); - idr->idr_rt.rnode = NULL; + idr->idr_rt.xa_head = NULL; root_tag_set(&idr->idr_rt, IDR_FREE); } EXPORT_SYMBOL(idr_destroy); @@ -2228,31 +1597,6 @@ radix_tree_node_ctor(void *arg) INIT_LIST_HEAD(&node->private_list); } -static __init unsigned long __maxindex(unsigned int height) -{ - unsigned int width = height * RADIX_TREE_MAP_SHIFT; - int shift = RADIX_TREE_INDEX_BITS - width; - - if (shift < 0) - return ~0UL; - if (shift >= BITS_PER_LONG) - return 0UL; - return ~0UL >> shift; -} - -static __init void radix_tree_init_maxnodes(void) -{ - unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1]; - unsigned int i, j; - - for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++) - height_to_maxindex[i] = __maxindex(i); - for (i = 0; i < ARRAY_SIZE(height_to_maxnodes); i++) { - for (j = i; j > 0; j--) - height_to_maxnodes[i] += height_to_maxindex[j - 1] + 1; - } -} - static int radix_tree_cpu_dead(unsigned int cpu) { struct radix_tree_preload *rtp; @@ -2266,8 +1610,6 @@ static int radix_tree_cpu_dead(unsigned int cpu) kmem_cache_free(radix_tree_node_cachep, node); rtp->nr--; } - kfree(per_cpu(ida_bitmap, cpu)); - per_cpu(ida_bitmap, cpu) = NULL; return 0; } @@ -2277,11 +1619,11 @@ void __init radix_tree_init(void) BUILD_BUG_ON(RADIX_TREE_MAX_TAGS + __GFP_BITS_SHIFT > 32); BUILD_BUG_ON(ROOT_IS_IDR & ~GFP_ZONEMASK); + BUILD_BUG_ON(XA_CHUNK_SIZE > 255); radix_tree_node_cachep = kmem_cache_create("radix_tree_node", sizeof(struct radix_tree_node), 0, SLAB_PANIC | SLAB_RECLAIM_ACCOUNT, radix_tree_node_ctor); - radix_tree_init_maxnodes(); ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead", NULL, radix_tree_cpu_dead); WARN_ON(ret < 0); diff --git a/lib/test_xarray.c b/lib/test_xarray.c new file mode 100644 index 000000000000..aa47754150ce --- /dev/null +++ b/lib/test_xarray.c @@ -0,0 +1,1238 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * test_xarray.c: Test the XArray API + * Copyright (c) 2017-2018 Microsoft Corporation + * Author: Matthew Wilcox + */ + +#include +#include + +static unsigned int tests_run; +static unsigned int tests_passed; + +#ifndef XA_DEBUG +# ifdef __KERNEL__ +void xa_dump(const struct xarray *xa) { } +# endif +#undef XA_BUG_ON +#define XA_BUG_ON(xa, x) do { \ + tests_run++; \ + if (x) { \ + printk("BUG at %s:%d\n", __func__, __LINE__); \ + xa_dump(xa); \ + dump_stack(); \ + } else { \ + tests_passed++; \ + } \ +} while (0) +#endif + +static void *xa_store_index(struct xarray *xa, unsigned long index, gfp_t gfp) +{ + return xa_store(xa, index, xa_mk_value(index & LONG_MAX), gfp); +} + +static void xa_alloc_index(struct xarray *xa, unsigned long index, gfp_t gfp) +{ + u32 id = 0; + + XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, xa_mk_value(index & LONG_MAX), + gfp) != 0); + XA_BUG_ON(xa, id != index); +} + +static void xa_erase_index(struct xarray *xa, unsigned long index) +{ + XA_BUG_ON(xa, xa_erase(xa, index) != xa_mk_value(index & LONG_MAX)); + XA_BUG_ON(xa, xa_load(xa, index) != NULL); +} + +/* + * If anyone needs this, please move it to xarray.c. We have no current + * users outside the test suite because all current multislot users want + * to use the advanced API. + */ +static void *xa_store_order(struct xarray *xa, unsigned long index, + unsigned order, void *entry, gfp_t gfp) +{ + XA_STATE_ORDER(xas, xa, index, order); + void *curr; + + do { + xas_lock(&xas); + curr = xas_store(&xas, entry); + xas_unlock(&xas); + } while (xas_nomem(&xas, gfp)); + + return curr; +} + +static noinline void check_xa_err(struct xarray *xa) +{ + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 0, GFP_NOWAIT)) != 0); + XA_BUG_ON(xa, xa_err(xa_erase(xa, 0)) != 0); +#ifndef __KERNEL__ + /* The kernel does not fail GFP_NOWAIT allocations */ + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_NOWAIT)) != -ENOMEM); + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_NOWAIT)) != -ENOMEM); +#endif + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_KERNEL)) != 0); + XA_BUG_ON(xa, xa_err(xa_store(xa, 1, xa_mk_value(0), GFP_KERNEL)) != 0); + XA_BUG_ON(xa, xa_err(xa_erase(xa, 1)) != 0); +// kills the test-suite :-( +// XA_BUG_ON(xa, xa_err(xa_store(xa, 0, xa_mk_internal(0), 0)) != -EINVAL); +} + +static noinline void check_xas_retry(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + + xa_store_index(xa, 0, GFP_KERNEL); + xa_store_index(xa, 1, GFP_KERNEL); + + rcu_read_lock(); + XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != xa_mk_value(0)); + xa_erase_index(xa, 1); + XA_BUG_ON(xa, !xa_is_retry(xas_reload(&xas))); + XA_BUG_ON(xa, xas_retry(&xas, NULL)); + XA_BUG_ON(xa, xas_retry(&xas, xa_mk_value(0))); + xas_reset(&xas); + XA_BUG_ON(xa, xas.xa_node != XAS_RESTART); + XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) != xa_mk_value(0)); + XA_BUG_ON(xa, xas.xa_node != NULL); + + XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL); + XA_BUG_ON(xa, !xa_is_internal(xas_reload(&xas))); + xas.xa_node = XAS_RESTART; + XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) != xa_mk_value(0)); + rcu_read_unlock(); + + /* Make sure we can iterate through retry entries */ + xas_lock(&xas); + xas_set(&xas, 0); + xas_store(&xas, XA_RETRY_ENTRY); + xas_set(&xas, 1); + xas_store(&xas, XA_RETRY_ENTRY); + + xas_set(&xas, 0); + xas_for_each(&xas, entry, ULONG_MAX) { + xas_store(&xas, xa_mk_value(xas.xa_index)); + } + xas_unlock(&xas); + + xa_erase_index(xa, 0); + xa_erase_index(xa, 1); +} + +static noinline void check_xa_load(struct xarray *xa) +{ + unsigned long i, j; + + for (i = 0; i < 1024; i++) { + for (j = 0; j < 1024; j++) { + void *entry = xa_load(xa, j); + if (j < i) + XA_BUG_ON(xa, xa_to_value(entry) != j); + else + XA_BUG_ON(xa, entry); + } + XA_BUG_ON(xa, xa_store_index(xa, i, GFP_KERNEL) != NULL); + } + + for (i = 0; i < 1024; i++) { + for (j = 0; j < 1024; j++) { + void *entry = xa_load(xa, j); + if (j >= i) + XA_BUG_ON(xa, xa_to_value(entry) != j); + else + XA_BUG_ON(xa, entry); + } + xa_erase_index(xa, i); + } + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_xa_mark_1(struct xarray *xa, unsigned long index) +{ + unsigned int order; + unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 8 : 1; + + /* NULL elements have no marks set */ + XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); + xa_set_mark(xa, index, XA_MARK_0); + XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); + + /* Storing a pointer will not make a mark appear */ + XA_BUG_ON(xa, xa_store_index(xa, index, GFP_KERNEL) != NULL); + XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); + xa_set_mark(xa, index, XA_MARK_0); + XA_BUG_ON(xa, !xa_get_mark(xa, index, XA_MARK_0)); + + /* Setting one mark will not set another mark */ + XA_BUG_ON(xa, xa_get_mark(xa, index + 1, XA_MARK_0)); + XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_1)); + + /* Storing NULL clears marks, and they can't be set again */ + xa_erase_index(xa, index); + XA_BUG_ON(xa, !xa_empty(xa)); + XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); + xa_set_mark(xa, index, XA_MARK_0); + XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); + + /* + * Storing a multi-index entry over entries with marks gives the + * entire entry the union of the marks + */ + BUG_ON((index % 4) != 0); + for (order = 2; order < max_order; order++) { + unsigned long base = round_down(index, 1UL << order); + unsigned long next = base + (1UL << order); + unsigned long i; + + XA_BUG_ON(xa, xa_store_index(xa, index + 1, GFP_KERNEL)); + xa_set_mark(xa, index + 1, XA_MARK_0); + XA_BUG_ON(xa, xa_store_index(xa, index + 2, GFP_KERNEL)); + xa_set_mark(xa, index + 2, XA_MARK_1); + XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL)); + xa_store_order(xa, index, order, xa_mk_value(index), + GFP_KERNEL); + for (i = base; i < next; i++) { + XA_STATE(xas, xa, i); + unsigned int seen = 0; + void *entry; + + XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_0)); + XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_1)); + XA_BUG_ON(xa, xa_get_mark(xa, i, XA_MARK_2)); + + /* We should see two elements in the array */ + xas_for_each(&xas, entry, ULONG_MAX) + seen++; + XA_BUG_ON(xa, seen != 2); + + /* One of which is marked */ + xas_set(&xas, 0); + seen = 0; + xas_for_each_marked(&xas, entry, ULONG_MAX, XA_MARK_0) + seen++; + XA_BUG_ON(xa, seen != 1); + } + XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_0)); + XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_1)); + XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_2)); + xa_erase_index(xa, index); + xa_erase_index(xa, next); + XA_BUG_ON(xa, !xa_empty(xa)); + } + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_xa_mark_2(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + unsigned long index; + unsigned int count = 0; + void *entry; + + xa_store_index(xa, 0, GFP_KERNEL); + xa_set_mark(xa, 0, XA_MARK_0); + xas_lock(&xas); + xas_load(&xas); + xas_init_marks(&xas); + xas_unlock(&xas); + XA_BUG_ON(xa, !xa_get_mark(xa, 0, XA_MARK_0) == 0); + + for (index = 3500; index < 4500; index++) { + xa_store_index(xa, index, GFP_KERNEL); + xa_set_mark(xa, index, XA_MARK_0); + } + + xas_reset(&xas); + rcu_read_lock(); + xas_for_each_marked(&xas, entry, ULONG_MAX, XA_MARK_0) + count++; + rcu_read_unlock(); + XA_BUG_ON(xa, count != 1000); + + xas_lock(&xas); + xas_for_each(&xas, entry, ULONG_MAX) { + xas_init_marks(&xas); + XA_BUG_ON(xa, !xa_get_mark(xa, xas.xa_index, XA_MARK_0)); + XA_BUG_ON(xa, !xas_get_mark(&xas, XA_MARK_0)); + } + xas_unlock(&xas); + + xa_destroy(xa); +} + +static noinline void check_xa_mark(struct xarray *xa) +{ + unsigned long index; + + for (index = 0; index < 16384; index += 4) + check_xa_mark_1(xa, index); + + check_xa_mark_2(xa); +} + +static noinline void check_xa_shrink(struct xarray *xa) +{ + XA_STATE(xas, xa, 1); + struct xa_node *node; + unsigned int order; + unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 15 : 1; + + XA_BUG_ON(xa, !xa_empty(xa)); + XA_BUG_ON(xa, xa_store_index(xa, 0, GFP_KERNEL) != NULL); + XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL); + + /* + * Check that erasing the entry at 1 shrinks the tree and properly + * marks the node as being deleted. + */ + xas_lock(&xas); + XA_BUG_ON(xa, xas_load(&xas) != xa_mk_value(1)); + node = xas.xa_node; + XA_BUG_ON(xa, xa_entry_locked(xa, node, 0) != xa_mk_value(0)); + XA_BUG_ON(xa, xas_store(&xas, NULL) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 1) != NULL); + XA_BUG_ON(xa, xas.xa_node != XAS_BOUNDS); + XA_BUG_ON(xa, xa_entry_locked(xa, node, 0) != XA_RETRY_ENTRY); + XA_BUG_ON(xa, xas_load(&xas) != NULL); + xas_unlock(&xas); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0)); + xa_erase_index(xa, 0); + XA_BUG_ON(xa, !xa_empty(xa)); + + for (order = 0; order < max_order; order++) { + unsigned long max = (1UL << order) - 1; + xa_store_order(xa, 0, order, xa_mk_value(0), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, max) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, max + 1) != NULL); + rcu_read_lock(); + node = xa_head(xa); + rcu_read_unlock(); + XA_BUG_ON(xa, xa_store_index(xa, ULONG_MAX, GFP_KERNEL) != + NULL); + rcu_read_lock(); + XA_BUG_ON(xa, xa_head(xa) == node); + rcu_read_unlock(); + XA_BUG_ON(xa, xa_load(xa, max + 1) != NULL); + xa_erase_index(xa, ULONG_MAX); + XA_BUG_ON(xa, xa->xa_head != node); + xa_erase_index(xa, 0); + } +} + +static noinline void check_cmpxchg(struct xarray *xa) +{ + void *FIVE = xa_mk_value(5); + void *SIX = xa_mk_value(6); + void *LOTS = xa_mk_value(12345678); + + XA_BUG_ON(xa, !xa_empty(xa)); + XA_BUG_ON(xa, xa_store_index(xa, 12345678, GFP_KERNEL) != NULL); + XA_BUG_ON(xa, xa_insert(xa, 12345678, xa, GFP_KERNEL) != -EEXIST); + XA_BUG_ON(xa, xa_cmpxchg(xa, 12345678, SIX, FIVE, GFP_KERNEL) != LOTS); + XA_BUG_ON(xa, xa_cmpxchg(xa, 12345678, LOTS, FIVE, GFP_KERNEL) != LOTS); + XA_BUG_ON(xa, xa_cmpxchg(xa, 12345678, FIVE, LOTS, GFP_KERNEL) != FIVE); + XA_BUG_ON(xa, xa_cmpxchg(xa, 5, FIVE, NULL, GFP_KERNEL) != NULL); + XA_BUG_ON(xa, xa_cmpxchg(xa, 5, NULL, FIVE, GFP_KERNEL) != NULL); + xa_erase_index(xa, 12345678); + xa_erase_index(xa, 5); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_reserve(struct xarray *xa) +{ + void *entry; + unsigned long index = 0; + + /* An array with a reserved entry is not empty */ + XA_BUG_ON(xa, !xa_empty(xa)); + xa_reserve(xa, 12345678, GFP_KERNEL); + XA_BUG_ON(xa, xa_empty(xa)); + XA_BUG_ON(xa, xa_load(xa, 12345678)); + xa_release(xa, 12345678); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Releasing a used entry does nothing */ + xa_reserve(xa, 12345678, GFP_KERNEL); + XA_BUG_ON(xa, xa_store_index(xa, 12345678, GFP_NOWAIT) != NULL); + xa_release(xa, 12345678); + xa_erase_index(xa, 12345678); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* cmpxchg sees a reserved entry as NULL */ + xa_reserve(xa, 12345678, GFP_KERNEL); + XA_BUG_ON(xa, xa_cmpxchg(xa, 12345678, NULL, xa_mk_value(12345678), + GFP_NOWAIT) != NULL); + xa_release(xa, 12345678); + xa_erase_index(xa, 12345678); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Can iterate through a reserved entry */ + xa_store_index(xa, 5, GFP_KERNEL); + xa_reserve(xa, 6, GFP_KERNEL); + xa_store_index(xa, 7, GFP_KERNEL); + + xa_for_each(xa, entry, index, ULONG_MAX, XA_PRESENT) { + XA_BUG_ON(xa, index != 5 && index != 7); + } + xa_destroy(xa); +} + +static noinline void check_xas_erase(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + void *entry; + unsigned long i, j; + + for (i = 0; i < 200; i++) { + for (j = i; j < 2 * i + 17; j++) { + xas_set(&xas, j); + do { + xas_lock(&xas); + xas_store(&xas, xa_mk_value(j)); + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); + } + + xas_set(&xas, ULONG_MAX); + do { + xas_lock(&xas); + xas_store(&xas, xa_mk_value(0)); + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); + + xas_lock(&xas); + xas_store(&xas, NULL); + + xas_set(&xas, 0); + j = i; + xas_for_each(&xas, entry, ULONG_MAX) { + XA_BUG_ON(xa, entry != xa_mk_value(j)); + xas_store(&xas, NULL); + j++; + } + xas_unlock(&xas); + XA_BUG_ON(xa, !xa_empty(xa)); + } +} + +#ifdef CONFIG_XARRAY_MULTI +static noinline void check_multi_store_1(struct xarray *xa, unsigned long index, + unsigned int order) +{ + XA_STATE(xas, xa, index); + unsigned long min = index & ~((1UL << order) - 1); + unsigned long max = min + (1UL << order); + + xa_store_order(xa, index, order, xa_mk_value(index), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, min) != xa_mk_value(index)); + XA_BUG_ON(xa, xa_load(xa, max - 1) != xa_mk_value(index)); + XA_BUG_ON(xa, xa_load(xa, max) != NULL); + XA_BUG_ON(xa, xa_load(xa, min - 1) != NULL); + + XA_BUG_ON(xa, xas_store(&xas, xa_mk_value(min)) != xa_mk_value(index)); + XA_BUG_ON(xa, xa_load(xa, min) != xa_mk_value(min)); + XA_BUG_ON(xa, xa_load(xa, max - 1) != xa_mk_value(min)); + XA_BUG_ON(xa, xa_load(xa, max) != NULL); + XA_BUG_ON(xa, xa_load(xa, min - 1) != NULL); + + xa_erase_index(xa, min); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_multi_store_2(struct xarray *xa, unsigned long index, + unsigned int order) +{ + XA_STATE(xas, xa, index); + xa_store_order(xa, index, order, xa_mk_value(0), GFP_KERNEL); + + XA_BUG_ON(xa, xas_store(&xas, xa_mk_value(1)) != xa_mk_value(0)); + XA_BUG_ON(xa, xas.xa_index != index); + XA_BUG_ON(xa, xas_store(&xas, NULL) != xa_mk_value(1)); + XA_BUG_ON(xa, !xa_empty(xa)); +} +#endif + +static noinline void check_multi_store(struct xarray *xa) +{ +#ifdef CONFIG_XARRAY_MULTI + unsigned long i, j, k; + unsigned int max_order = (sizeof(long) == 4) ? 30 : 60; + + /* Loading from any position returns the same value */ + xa_store_order(xa, 0, 1, xa_mk_value(0), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 2) != NULL); + rcu_read_lock(); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 2); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2); + rcu_read_unlock(); + + /* Storing adjacent to the value does not alter the value */ + xa_store(xa, 3, xa, GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 2) != NULL); + rcu_read_lock(); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 3); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2); + rcu_read_unlock(); + + /* Overwriting multiple indexes works */ + xa_store_order(xa, 0, 2, xa_mk_value(1), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 2) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 3) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 4) != NULL); + rcu_read_lock(); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 4); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 4); + rcu_read_unlock(); + + /* We can erase multiple values with a single store */ + xa_store_order(xa, 0, 63, NULL, GFP_KERNEL); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Even when the first slot is empty but the others aren't */ + xa_store_index(xa, 1, GFP_KERNEL); + xa_store_index(xa, 2, GFP_KERNEL); + xa_store_order(xa, 0, 2, NULL, GFP_KERNEL); + XA_BUG_ON(xa, !xa_empty(xa)); + + for (i = 0; i < max_order; i++) { + for (j = 0; j < max_order; j++) { + xa_store_order(xa, 0, i, xa_mk_value(i), GFP_KERNEL); + xa_store_order(xa, 0, j, xa_mk_value(j), GFP_KERNEL); + + for (k = 0; k < max_order; k++) { + void *entry = xa_load(xa, (1UL << k) - 1); + if ((i < k) && (j < k)) + XA_BUG_ON(xa, entry != NULL); + else + XA_BUG_ON(xa, entry != xa_mk_value(j)); + } + + xa_erase(xa, 0); + XA_BUG_ON(xa, !xa_empty(xa)); + } + } + + for (i = 0; i < 20; i++) { + check_multi_store_1(xa, 200, i); + check_multi_store_1(xa, 0, i); + check_multi_store_1(xa, (1UL << i) + 1, i); + } + check_multi_store_2(xa, 4095, 9); +#endif +} + +static DEFINE_XARRAY_ALLOC(xa0); + +static noinline void check_xa_alloc(void) +{ + int i; + u32 id; + + /* An empty array should assign 0 to the first alloc */ + xa_alloc_index(&xa0, 0, GFP_KERNEL); + + /* Erasing it should make the array empty again */ + xa_erase_index(&xa0, 0); + XA_BUG_ON(&xa0, !xa_empty(&xa0)); + + /* And it should assign 0 again */ + xa_alloc_index(&xa0, 0, GFP_KERNEL); + + /* The next assigned ID should be 1 */ + xa_alloc_index(&xa0, 1, GFP_KERNEL); + xa_erase_index(&xa0, 1); + + /* Storing a value should mark it used */ + xa_store_index(&xa0, 1, GFP_KERNEL); + xa_alloc_index(&xa0, 2, GFP_KERNEL); + + /* If we then erase 0, it should be free */ + xa_erase_index(&xa0, 0); + xa_alloc_index(&xa0, 0, GFP_KERNEL); + + xa_erase_index(&xa0, 1); + xa_erase_index(&xa0, 2); + + for (i = 1; i < 5000; i++) { + xa_alloc_index(&xa0, i, GFP_KERNEL); + } + + xa_destroy(&xa0); + + id = 0xfffffffeU; + XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, UINT_MAX, xa_mk_value(0), + GFP_KERNEL) != 0); + XA_BUG_ON(&xa0, id != 0xfffffffeU); + XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, UINT_MAX, xa_mk_value(0), + GFP_KERNEL) != 0); + XA_BUG_ON(&xa0, id != 0xffffffffU); + XA_BUG_ON(&xa0, xa_alloc(&xa0, &id, UINT_MAX, xa_mk_value(0), + GFP_KERNEL) != -ENOSPC); + XA_BUG_ON(&xa0, id != 0xffffffffU); + xa_destroy(&xa0); +} + +static noinline void __check_store_iter(struct xarray *xa, unsigned long start, + unsigned int order, unsigned int present) +{ + XA_STATE_ORDER(xas, xa, start, order); + void *entry; + unsigned int count = 0; + +retry: + xas_lock(&xas); + xas_for_each_conflict(&xas, entry) { + XA_BUG_ON(xa, !xa_is_value(entry)); + XA_BUG_ON(xa, entry < xa_mk_value(start)); + XA_BUG_ON(xa, entry > xa_mk_value(start + (1UL << order) - 1)); + count++; + } + xas_store(&xas, xa_mk_value(start)); + xas_unlock(&xas); + if (xas_nomem(&xas, GFP_KERNEL)) { + count = 0; + goto retry; + } + XA_BUG_ON(xa, xas_error(&xas)); + XA_BUG_ON(xa, count != present); + XA_BUG_ON(xa, xa_load(xa, start) != xa_mk_value(start)); + XA_BUG_ON(xa, xa_load(xa, start + (1UL << order) - 1) != + xa_mk_value(start)); + xa_erase_index(xa, start); +} + +static noinline void check_store_iter(struct xarray *xa) +{ + unsigned int i, j; + unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 20 : 1; + + for (i = 0; i < max_order; i++) { + unsigned int min = 1 << i; + unsigned int max = (2 << i) - 1; + __check_store_iter(xa, 0, i, 0); + XA_BUG_ON(xa, !xa_empty(xa)); + __check_store_iter(xa, min, i, 0); + XA_BUG_ON(xa, !xa_empty(xa)); + + xa_store_index(xa, min, GFP_KERNEL); + __check_store_iter(xa, min, i, 1); + XA_BUG_ON(xa, !xa_empty(xa)); + xa_store_index(xa, max, GFP_KERNEL); + __check_store_iter(xa, min, i, 1); + XA_BUG_ON(xa, !xa_empty(xa)); + + for (j = 0; j < min; j++) + xa_store_index(xa, j, GFP_KERNEL); + __check_store_iter(xa, 0, i, min); + XA_BUG_ON(xa, !xa_empty(xa)); + for (j = 0; j < min; j++) + xa_store_index(xa, min + j, GFP_KERNEL); + __check_store_iter(xa, min, i, min); + XA_BUG_ON(xa, !xa_empty(xa)); + } +#ifdef CONFIG_XARRAY_MULTI + xa_store_index(xa, 63, GFP_KERNEL); + xa_store_index(xa, 65, GFP_KERNEL); + __check_store_iter(xa, 64, 2, 1); + xa_erase_index(xa, 63); +#endif + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_multi_find(struct xarray *xa) +{ +#ifdef CONFIG_XARRAY_MULTI + unsigned long index; + + xa_store_order(xa, 12, 2, xa_mk_value(12), GFP_KERNEL); + XA_BUG_ON(xa, xa_store_index(xa, 16, GFP_KERNEL) != NULL); + + index = 0; + XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) != + xa_mk_value(12)); + XA_BUG_ON(xa, index != 12); + index = 13; + XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) != + xa_mk_value(12)); + XA_BUG_ON(xa, (index < 12) || (index >= 16)); + XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) != + xa_mk_value(16)); + XA_BUG_ON(xa, index != 16); + + xa_erase_index(xa, 12); + xa_erase_index(xa, 16); + XA_BUG_ON(xa, !xa_empty(xa)); +#endif +} + +static noinline void check_multi_find_2(struct xarray *xa) +{ + unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 10 : 1; + unsigned int i, j; + void *entry; + + for (i = 0; i < max_order; i++) { + unsigned long index = 1UL << i; + for (j = 0; j < index; j++) { + XA_STATE(xas, xa, j + index); + xa_store_index(xa, index - 1, GFP_KERNEL); + xa_store_order(xa, index, i, xa_mk_value(index), + GFP_KERNEL); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + xa_erase_index(xa, index); + } + rcu_read_unlock(); + xa_erase_index(xa, index - 1); + XA_BUG_ON(xa, !xa_empty(xa)); + } + } +} + +static noinline void check_find(struct xarray *xa) +{ + unsigned long i, j, k; + + XA_BUG_ON(xa, !xa_empty(xa)); + + /* + * Check xa_find with all pairs between 0 and 99 inclusive, + * starting at every index between 0 and 99 + */ + for (i = 0; i < 100; i++) { + XA_BUG_ON(xa, xa_store_index(xa, i, GFP_KERNEL) != NULL); + xa_set_mark(xa, i, XA_MARK_0); + for (j = 0; j < i; j++) { + XA_BUG_ON(xa, xa_store_index(xa, j, GFP_KERNEL) != + NULL); + xa_set_mark(xa, j, XA_MARK_0); + for (k = 0; k < 100; k++) { + unsigned long index = k; + void *entry = xa_find(xa, &index, ULONG_MAX, + XA_PRESENT); + if (k <= j) + XA_BUG_ON(xa, index != j); + else if (k <= i) + XA_BUG_ON(xa, index != i); + else + XA_BUG_ON(xa, entry != NULL); + + index = k; + entry = xa_find(xa, &index, ULONG_MAX, + XA_MARK_0); + if (k <= j) + XA_BUG_ON(xa, index != j); + else if (k <= i) + XA_BUG_ON(xa, index != i); + else + XA_BUG_ON(xa, entry != NULL); + } + xa_erase_index(xa, j); + XA_BUG_ON(xa, xa_get_mark(xa, j, XA_MARK_0)); + XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_0)); + } + xa_erase_index(xa, i); + XA_BUG_ON(xa, xa_get_mark(xa, i, XA_MARK_0)); + } + XA_BUG_ON(xa, !xa_empty(xa)); + check_multi_find(xa); + check_multi_find_2(xa); +} + +/* See find_swap_entry() in mm/shmem.c */ +static noinline unsigned long xa_find_entry(struct xarray *xa, void *item) +{ + XA_STATE(xas, xa, 0); + unsigned int checked = 0; + void *entry; + + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (xas_retry(&xas, entry)) + continue; + if (entry == item) + break; + checked++; + if ((checked % 4) != 0) + continue; + xas_pause(&xas); + } + rcu_read_unlock(); + + return entry ? xas.xa_index : -1; +} + +static noinline void check_find_entry(struct xarray *xa) +{ +#ifdef CONFIG_XARRAY_MULTI + unsigned int order; + unsigned long offset, index; + + for (order = 0; order < 20; order++) { + for (offset = 0; offset < (1UL << (order + 3)); + offset += (1UL << order)) { + for (index = 0; index < (1UL << (order + 5)); + index += (1UL << order)) { + xa_store_order(xa, index, order, + xa_mk_value(index), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, index) != + xa_mk_value(index)); + XA_BUG_ON(xa, xa_find_entry(xa, + xa_mk_value(index)) != index); + } + XA_BUG_ON(xa, xa_find_entry(xa, xa) != -1); + xa_destroy(xa); + } + } +#endif + + XA_BUG_ON(xa, xa_find_entry(xa, xa) != -1); + xa_store_index(xa, ULONG_MAX, GFP_KERNEL); + XA_BUG_ON(xa, xa_find_entry(xa, xa) != -1); + XA_BUG_ON(xa, xa_find_entry(xa, xa_mk_value(LONG_MAX)) != -1); + xa_erase_index(xa, ULONG_MAX); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_move_small(struct xarray *xa, unsigned long idx) +{ + XA_STATE(xas, xa, 0); + unsigned long i; + + xa_store_index(xa, 0, GFP_KERNEL); + xa_store_index(xa, idx, GFP_KERNEL); + + rcu_read_lock(); + for (i = 0; i < idx * 4; i++) { + void *entry = xas_next(&xas); + if (i <= idx) + XA_BUG_ON(xa, xas.xa_node == XAS_RESTART); + XA_BUG_ON(xa, xas.xa_index != i); + if (i == 0 || i == idx) + XA_BUG_ON(xa, entry != xa_mk_value(i)); + else + XA_BUG_ON(xa, entry != NULL); + } + xas_next(&xas); + XA_BUG_ON(xa, xas.xa_index != i); + + do { + void *entry = xas_prev(&xas); + i--; + if (i <= idx) + XA_BUG_ON(xa, xas.xa_node == XAS_RESTART); + XA_BUG_ON(xa, xas.xa_index != i); + if (i == 0 || i == idx) + XA_BUG_ON(xa, entry != xa_mk_value(i)); + else + XA_BUG_ON(xa, entry != NULL); + } while (i > 0); + + xas_set(&xas, ULONG_MAX); + XA_BUG_ON(xa, xas_next(&xas) != NULL); + XA_BUG_ON(xa, xas.xa_index != ULONG_MAX); + XA_BUG_ON(xa, xas_next(&xas) != xa_mk_value(0)); + XA_BUG_ON(xa, xas.xa_index != 0); + XA_BUG_ON(xa, xas_prev(&xas) != NULL); + XA_BUG_ON(xa, xas.xa_index != ULONG_MAX); + rcu_read_unlock(); + + xa_erase_index(xa, 0); + xa_erase_index(xa, idx); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_move(struct xarray *xa) +{ + XA_STATE(xas, xa, (1 << 16) - 1); + unsigned long i; + + for (i = 0; i < (1 << 16); i++) + XA_BUG_ON(xa, xa_store_index(xa, i, GFP_KERNEL) != NULL); + + rcu_read_lock(); + do { + void *entry = xas_prev(&xas); + i--; + XA_BUG_ON(xa, entry != xa_mk_value(i)); + XA_BUG_ON(xa, i != xas.xa_index); + } while (i != 0); + + XA_BUG_ON(xa, xas_prev(&xas) != NULL); + XA_BUG_ON(xa, xas.xa_index != ULONG_MAX); + + do { + void *entry = xas_next(&xas); + XA_BUG_ON(xa, entry != xa_mk_value(i)); + XA_BUG_ON(xa, i != xas.xa_index); + i++; + } while (i < (1 << 16)); + rcu_read_unlock(); + + for (i = (1 << 8); i < (1 << 15); i++) + xa_erase_index(xa, i); + + i = xas.xa_index; + + rcu_read_lock(); + do { + void *entry = xas_prev(&xas); + i--; + if ((i < (1 << 8)) || (i >= (1 << 15))) + XA_BUG_ON(xa, entry != xa_mk_value(i)); + else + XA_BUG_ON(xa, entry != NULL); + XA_BUG_ON(xa, i != xas.xa_index); + } while (i != 0); + + XA_BUG_ON(xa, xas_prev(&xas) != NULL); + XA_BUG_ON(xa, xas.xa_index != ULONG_MAX); + + do { + void *entry = xas_next(&xas); + if ((i < (1 << 8)) || (i >= (1 << 15))) + XA_BUG_ON(xa, entry != xa_mk_value(i)); + else + XA_BUG_ON(xa, entry != NULL); + XA_BUG_ON(xa, i != xas.xa_index); + i++; + } while (i < (1 << 16)); + rcu_read_unlock(); + + xa_destroy(xa); + + for (i = 0; i < 16; i++) + check_move_small(xa, 1UL << i); + + for (i = 2; i < 16; i++) + check_move_small(xa, (1UL << i) - 1); +} + +static noinline void xa_store_many_order(struct xarray *xa, + unsigned long index, unsigned order) +{ + XA_STATE_ORDER(xas, xa, index, order); + unsigned int i = 0; + + do { + xas_lock(&xas); + XA_BUG_ON(xa, xas_find_conflict(&xas)); + xas_create_range(&xas); + if (xas_error(&xas)) + goto unlock; + for (i = 0; i < (1U << order); i++) { + XA_BUG_ON(xa, xas_store(&xas, xa_mk_value(index + i))); + xas_next(&xas); + } +unlock: + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); + + XA_BUG_ON(xa, xas_error(&xas)); +} + +static noinline void check_create_range_1(struct xarray *xa, + unsigned long index, unsigned order) +{ + unsigned long i; + + xa_store_many_order(xa, index, order); + for (i = index; i < index + (1UL << order); i++) + xa_erase_index(xa, i); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_create_range_2(struct xarray *xa, unsigned order) +{ + unsigned long i; + unsigned long nr = 1UL << order; + + for (i = 0; i < nr * nr; i += nr) + xa_store_many_order(xa, i, order); + for (i = 0; i < nr * nr; i++) + xa_erase_index(xa, i); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_create_range_3(void) +{ + XA_STATE(xas, NULL, 0); + xas_set_err(&xas, -EEXIST); + xas_create_range(&xas); + XA_BUG_ON(NULL, xas_error(&xas) != -EEXIST); +} + +static noinline void check_create_range_4(struct xarray *xa, + unsigned long index, unsigned order) +{ + XA_STATE_ORDER(xas, xa, index, order); + unsigned long base = xas.xa_index; + unsigned long i = 0; + + xa_store_index(xa, index, GFP_KERNEL); + do { + xas_lock(&xas); + xas_create_range(&xas); + if (xas_error(&xas)) + goto unlock; + for (i = 0; i < (1UL << order); i++) { + void *old = xas_store(&xas, xa_mk_value(base + i)); + if (xas.xa_index == index) + XA_BUG_ON(xa, old != xa_mk_value(base + i)); + else + XA_BUG_ON(xa, old != NULL); + xas_next(&xas); + } +unlock: + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); + + XA_BUG_ON(xa, xas_error(&xas)); + + for (i = base; i < base + (1UL << order); i++) + xa_erase_index(xa, i); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_create_range(struct xarray *xa) +{ + unsigned int order; + unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 12 : 1; + + for (order = 0; order < max_order; order++) { + check_create_range_1(xa, 0, order); + check_create_range_1(xa, 1U << order, order); + check_create_range_1(xa, 2U << order, order); + check_create_range_1(xa, 3U << order, order); + check_create_range_1(xa, 1U << 24, order); + if (order < 10) + check_create_range_2(xa, order); + + check_create_range_4(xa, 0, order); + check_create_range_4(xa, 1U << order, order); + check_create_range_4(xa, 2U << order, order); + check_create_range_4(xa, 3U << order, order); + check_create_range_4(xa, 1U << 24, order); + + check_create_range_4(xa, 1, order); + check_create_range_4(xa, (1U << order) + 1, order); + check_create_range_4(xa, (2U << order) + 1, order); + check_create_range_4(xa, (2U << order) - 1, order); + check_create_range_4(xa, (3U << order) + 1, order); + check_create_range_4(xa, (3U << order) - 1, order); + check_create_range_4(xa, (1U << 24) + 1, order); + } + + check_create_range_3(); +} + +static noinline void __check_store_range(struct xarray *xa, unsigned long first, + unsigned long last) +{ +#ifdef CONFIG_XARRAY_MULTI + xa_store_range(xa, first, last, xa_mk_value(first), GFP_KERNEL); + + XA_BUG_ON(xa, xa_load(xa, first) != xa_mk_value(first)); + XA_BUG_ON(xa, xa_load(xa, last) != xa_mk_value(first)); + XA_BUG_ON(xa, xa_load(xa, first - 1) != NULL); + XA_BUG_ON(xa, xa_load(xa, last + 1) != NULL); + + xa_store_range(xa, first, last, NULL, GFP_KERNEL); +#endif + + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_store_range(struct xarray *xa) +{ + unsigned long i, j; + + for (i = 0; i < 128; i++) { + for (j = i; j < 128; j++) { + __check_store_range(xa, i, j); + __check_store_range(xa, 128 + i, 128 + j); + __check_store_range(xa, 4095 + i, 4095 + j); + __check_store_range(xa, 4096 + i, 4096 + j); + __check_store_range(xa, 123456 + i, 123456 + j); + __check_store_range(xa, UINT_MAX + i, UINT_MAX + j); + } + } +} + +static LIST_HEAD(shadow_nodes); + +static void test_update_node(struct xa_node *node) +{ + if (node->count && node->count == node->nr_values) { + if (list_empty(&node->private_list)) + list_add(&shadow_nodes, &node->private_list); + } else { + if (!list_empty(&node->private_list)) + list_del_init(&node->private_list); + } +} + +static noinline void shadow_remove(struct xarray *xa) +{ + struct xa_node *node; + + xa_lock(xa); + while ((node = list_first_entry_or_null(&shadow_nodes, + struct xa_node, private_list))) { + XA_STATE(xas, node->array, 0); + XA_BUG_ON(xa, node->array != xa); + list_del_init(&node->private_list); + xas.xa_node = xa_parent_locked(node->array, node); + xas.xa_offset = node->offset; + xas.xa_shift = node->shift + XA_CHUNK_SHIFT; + xas_set_update(&xas, test_update_node); + xas_store(&xas, NULL); + } + xa_unlock(xa); +} + +static noinline void check_workingset(struct xarray *xa, unsigned long index) +{ + XA_STATE(xas, xa, index); + xas_set_update(&xas, test_update_node); + + do { + xas_lock(&xas); + xas_store(&xas, xa_mk_value(0)); + xas_next(&xas); + xas_store(&xas, xa_mk_value(1)); + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); + + XA_BUG_ON(xa, list_empty(&shadow_nodes)); + + xas_lock(&xas); + xas_next(&xas); + xas_store(&xas, &xas); + XA_BUG_ON(xa, !list_empty(&shadow_nodes)); + + xas_store(&xas, xa_mk_value(2)); + xas_unlock(&xas); + XA_BUG_ON(xa, list_empty(&shadow_nodes)); + + shadow_remove(xa); + XA_BUG_ON(xa, !list_empty(&shadow_nodes)); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +/* + * Check that the pointer / value / sibling entries are accounted the + * way we expect them to be. + */ +static noinline void check_account(struct xarray *xa) +{ +#ifdef CONFIG_XARRAY_MULTI + unsigned int order; + + for (order = 1; order < 12; order++) { + XA_STATE(xas, xa, 1 << order); + + xa_store_order(xa, 0, order, xa, GFP_KERNEL); + xas_load(&xas); + XA_BUG_ON(xa, xas.xa_node->count == 0); + XA_BUG_ON(xa, xas.xa_node->count > (1 << order)); + XA_BUG_ON(xa, xas.xa_node->nr_values != 0); + + xa_store_order(xa, 1 << order, order, xa_mk_value(1 << order), + GFP_KERNEL); + XA_BUG_ON(xa, xas.xa_node->count != xas.xa_node->nr_values * 2); + + xa_erase(xa, 1 << order); + XA_BUG_ON(xa, xas.xa_node->nr_values != 0); + + xa_erase(xa, 0); + XA_BUG_ON(xa, !xa_empty(xa)); + } +#endif +} + +static noinline void check_destroy(struct xarray *xa) +{ + unsigned long index; + + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Destroying an empty array is a no-op */ + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Destroying an array with a single entry */ + for (index = 0; index < 1000; index++) { + xa_store_index(xa, index, GFP_KERNEL); + XA_BUG_ON(xa, xa_empty(xa)); + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); + } + + /* Destroying an array with a single entry at ULONG_MAX */ + xa_store(xa, ULONG_MAX, xa, GFP_KERNEL); + XA_BUG_ON(xa, xa_empty(xa)); + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); + +#ifdef CONFIG_XARRAY_MULTI + /* Destroying an array with a multi-index entry */ + xa_store_order(xa, 1 << 11, 11, xa, GFP_KERNEL); + XA_BUG_ON(xa, xa_empty(xa)); + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); +#endif +} + +static DEFINE_XARRAY(array); + +static int xarray_checks(void) +{ + check_xa_err(&array); + check_xas_retry(&array); + check_xa_load(&array); + check_xa_mark(&array); + check_xa_shrink(&array); + check_xas_erase(&array); + check_cmpxchg(&array); + check_reserve(&array); + check_multi_store(&array); + check_xa_alloc(); + check_find(&array); + check_find_entry(&array); + check_account(&array); + check_destroy(&array); + check_move(&array); + check_create_range(&array); + check_store_range(&array); + check_store_iter(&array); + + check_workingset(&array, 0); + check_workingset(&array, 64); + check_workingset(&array, 4096); + + printk("XArray: %u of %u tests passed\n", tests_passed, tests_run); + return (tests_run == tests_passed) ? 0 : -EINVAL; +} + +static void xarray_exit(void) +{ +} + +module_init(xarray_checks); +module_exit(xarray_exit); +MODULE_AUTHOR("Matthew Wilcox "); +MODULE_LICENSE("GPL"); diff --git a/lib/xarray.c b/lib/xarray.c new file mode 100644 index 000000000000..8b176f009c08 --- /dev/null +++ b/lib/xarray.c @@ -0,0 +1,2036 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * XArray implementation + * Copyright (c) 2017 Microsoft Corporation + * Author: Matthew Wilcox + */ + +#include +#include +#include +#include +#include + +/* + * Coding conventions in this file: + * + * @xa is used to refer to the entire xarray. + * @xas is the 'xarray operation state'. It may be either a pointer to + * an xa_state, or an xa_state stored on the stack. This is an unfortunate + * ambiguity. + * @index is the index of the entry being operated on + * @mark is an xa_mark_t; a small number indicating one of the mark bits. + * @node refers to an xa_node; usually the primary one being operated on by + * this function. + * @offset is the index into the slots array inside an xa_node. + * @parent refers to the @xa_node closer to the head than @node. + * @entry refers to something stored in a slot in the xarray + */ + +static inline unsigned int xa_lock_type(const struct xarray *xa) +{ + return (__force unsigned int)xa->xa_flags & 3; +} + +static inline void xas_lock_type(struct xa_state *xas, unsigned int lock_type) +{ + if (lock_type == XA_LOCK_IRQ) + xas_lock_irq(xas); + else if (lock_type == XA_LOCK_BH) + xas_lock_bh(xas); + else + xas_lock(xas); +} + +static inline void xas_unlock_type(struct xa_state *xas, unsigned int lock_type) +{ + if (lock_type == XA_LOCK_IRQ) + xas_unlock_irq(xas); + else if (lock_type == XA_LOCK_BH) + xas_unlock_bh(xas); + else + xas_unlock(xas); +} + +static inline bool xa_track_free(const struct xarray *xa) +{ + return xa->xa_flags & XA_FLAGS_TRACK_FREE; +} + +static inline void xa_mark_set(struct xarray *xa, xa_mark_t mark) +{ + if (!(xa->xa_flags & XA_FLAGS_MARK(mark))) + xa->xa_flags |= XA_FLAGS_MARK(mark); +} + +static inline void xa_mark_clear(struct xarray *xa, xa_mark_t mark) +{ + if (xa->xa_flags & XA_FLAGS_MARK(mark)) + xa->xa_flags &= ~(XA_FLAGS_MARK(mark)); +} + +static inline unsigned long *node_marks(struct xa_node *node, xa_mark_t mark) +{ + return node->marks[(__force unsigned)mark]; +} + +static inline bool node_get_mark(struct xa_node *node, + unsigned int offset, xa_mark_t mark) +{ + return test_bit(offset, node_marks(node, mark)); +} + +/* returns true if the bit was set */ +static inline bool node_set_mark(struct xa_node *node, unsigned int offset, + xa_mark_t mark) +{ + return __test_and_set_bit(offset, node_marks(node, mark)); +} + +/* returns true if the bit was set */ +static inline bool node_clear_mark(struct xa_node *node, unsigned int offset, + xa_mark_t mark) +{ + return __test_and_clear_bit(offset, node_marks(node, mark)); +} + +static inline bool node_any_mark(struct xa_node *node, xa_mark_t mark) +{ + return !bitmap_empty(node_marks(node, mark), XA_CHUNK_SIZE); +} + +static inline void node_mark_all(struct xa_node *node, xa_mark_t mark) +{ + bitmap_fill(node_marks(node, mark), XA_CHUNK_SIZE); +} + +#define mark_inc(mark) do { \ + mark = (__force xa_mark_t)((__force unsigned)(mark) + 1); \ +} while (0) + +/* + * xas_squash_marks() - Merge all marks to the first entry + * @xas: Array operation state. + * + * Set a mark on the first entry if any entry has it set. Clear marks on + * all sibling entries. + */ +static void xas_squash_marks(const struct xa_state *xas) +{ + unsigned int mark = 0; + unsigned int limit = xas->xa_offset + xas->xa_sibs + 1; + + if (!xas->xa_sibs) + return; + + do { + unsigned long *marks = xas->xa_node->marks[mark]; + if (find_next_bit(marks, limit, xas->xa_offset + 1) == limit) + continue; + __set_bit(xas->xa_offset, marks); + bitmap_clear(marks, xas->xa_offset + 1, xas->xa_sibs); + } while (mark++ != (__force unsigned)XA_MARK_MAX); +} + +/* extracts the offset within this node from the index */ +static unsigned int get_offset(unsigned long index, struct xa_node *node) +{ + return (index >> node->shift) & XA_CHUNK_MASK; +} + +static void xas_set_offset(struct xa_state *xas) +{ + xas->xa_offset = get_offset(xas->xa_index, xas->xa_node); +} + +/* move the index either forwards (find) or backwards (sibling slot) */ +static void xas_move_index(struct xa_state *xas, unsigned long offset) +{ + unsigned int shift = xas->xa_node->shift; + xas->xa_index &= ~XA_CHUNK_MASK << shift; + xas->xa_index += offset << shift; +} + +static void xas_advance(struct xa_state *xas) +{ + xas->xa_offset++; + xas_move_index(xas, xas->xa_offset); +} + +static void *set_bounds(struct xa_state *xas) +{ + xas->xa_node = XAS_BOUNDS; + return NULL; +} + +/* + * Starts a walk. If the @xas is already valid, we assume that it's on + * the right path and just return where we've got to. If we're in an + * error state, return NULL. If the index is outside the current scope + * of the xarray, return NULL without changing @xas->xa_node. Otherwise + * set @xas->xa_node to NULL and return the current head of the array. + */ +static void *xas_start(struct xa_state *xas) +{ + void *entry; + + if (xas_valid(xas)) + return xas_reload(xas); + if (xas_error(xas)) + return NULL; + + entry = xa_head(xas->xa); + if (!xa_is_node(entry)) { + if (xas->xa_index) + return set_bounds(xas); + } else { + if ((xas->xa_index >> xa_to_node(entry)->shift) > XA_CHUNK_MASK) + return set_bounds(xas); + } + + xas->xa_node = NULL; + return entry; +} + +static void *xas_descend(struct xa_state *xas, struct xa_node *node) +{ + unsigned int offset = get_offset(xas->xa_index, node); + void *entry = xa_entry(xas->xa, node, offset); + + xas->xa_node = node; + if (xa_is_sibling(entry)) { + offset = xa_to_sibling(entry); + entry = xa_entry(xas->xa, node, offset); + } + + xas->xa_offset = offset; + return entry; +} + +/** + * xas_load() - Load an entry from the XArray (advanced). + * @xas: XArray operation state. + * + * Usually walks the @xas to the appropriate state to load the entry + * stored at xa_index. However, it will do nothing and return %NULL if + * @xas is in an error state. xas_load() will never expand the tree. + * + * If the xa_state is set up to operate on a multi-index entry, xas_load() + * may return %NULL or an internal entry, even if there are entries + * present within the range specified by @xas. + * + * Context: Any context. The caller should hold the xa_lock or the RCU lock. + * Return: Usually an entry in the XArray, but see description for exceptions. + */ +void *xas_load(struct xa_state *xas) +{ + void *entry = xas_start(xas); + + while (xa_is_node(entry)) { + struct xa_node *node = xa_to_node(entry); + + if (xas->xa_shift > node->shift) + break; + entry = xas_descend(xas, node); + } + return entry; +} +EXPORT_SYMBOL_GPL(xas_load); + +/* Move the radix tree node cache here */ +extern struct kmem_cache *radix_tree_node_cachep; +extern void radix_tree_node_rcu_free(struct rcu_head *head); + +#define XA_RCU_FREE ((struct xarray *)1) + +static void xa_node_free(struct xa_node *node) +{ + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); + node->array = XA_RCU_FREE; + call_rcu(&node->rcu_head, radix_tree_node_rcu_free); +} + +/* + * xas_destroy() - Free any resources allocated during the XArray operation. + * @xas: XArray operation state. + * + * This function is now internal-only. + */ +static void xas_destroy(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_alloc; + + if (!node) + return; + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); + kmem_cache_free(radix_tree_node_cachep, node); + xas->xa_alloc = NULL; +} + +/** + * xas_nomem() - Allocate memory if needed. + * @xas: XArray operation state. + * @gfp: Memory allocation flags. + * + * If we need to add new nodes to the XArray, we try to allocate memory + * with GFP_NOWAIT while holding the lock, which will usually succeed. + * If it fails, @xas is flagged as needing memory to continue. The caller + * should drop the lock and call xas_nomem(). If xas_nomem() succeeds, + * the caller should retry the operation. + * + * Forward progress is guaranteed as one node is allocated here and + * stored in the xa_state where it will be found by xas_alloc(). More + * nodes will likely be found in the slab allocator, but we do not tie + * them up here. + * + * Return: true if memory was needed, and was successfully allocated. + */ +bool xas_nomem(struct xa_state *xas, gfp_t gfp) +{ + if (xas->xa_node != XA_ERROR(-ENOMEM)) { + xas_destroy(xas); + return false; + } + xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); + if (!xas->xa_alloc) + return false; + XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list)); + xas->xa_node = XAS_RESTART; + return true; +} +EXPORT_SYMBOL_GPL(xas_nomem); + +/* + * __xas_nomem() - Drop locks and allocate memory if needed. + * @xas: XArray operation state. + * @gfp: Memory allocation flags. + * + * Internal variant of xas_nomem(). + * + * Return: true if memory was needed, and was successfully allocated. + */ +static bool __xas_nomem(struct xa_state *xas, gfp_t gfp) + __must_hold(xas->xa->xa_lock) +{ + unsigned int lock_type = xa_lock_type(xas->xa); + + if (xas->xa_node != XA_ERROR(-ENOMEM)) { + xas_destroy(xas); + return false; + } + if (gfpflags_allow_blocking(gfp)) { + xas_unlock_type(xas, lock_type); + xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); + xas_lock_type(xas, lock_type); + } else { + xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); + } + if (!xas->xa_alloc) + return false; + XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list)); + xas->xa_node = XAS_RESTART; + return true; +} + +static void xas_update(struct xa_state *xas, struct xa_node *node) +{ + if (xas->xa_update) + xas->xa_update(node); + else + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); +} + +static void *xas_alloc(struct xa_state *xas, unsigned int shift) +{ + struct xa_node *parent = xas->xa_node; + struct xa_node *node = xas->xa_alloc; + + if (xas_invalid(xas)) + return NULL; + + if (node) { + xas->xa_alloc = NULL; + } else { + node = kmem_cache_alloc(radix_tree_node_cachep, + GFP_NOWAIT | __GFP_NOWARN); + if (!node) { + xas_set_err(xas, -ENOMEM); + return NULL; + } + } + + if (parent) { + node->offset = xas->xa_offset; + parent->count++; + XA_NODE_BUG_ON(node, parent->count > XA_CHUNK_SIZE); + xas_update(xas, parent); + } + XA_NODE_BUG_ON(node, shift > BITS_PER_LONG); + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); + node->shift = shift; + node->count = 0; + node->nr_values = 0; + RCU_INIT_POINTER(node->parent, xas->xa_node); + node->array = xas->xa; + + return node; +} + +#ifdef CONFIG_XARRAY_MULTI +/* Returns the number of indices covered by a given xa_state */ +static unsigned long xas_size(const struct xa_state *xas) +{ + return (xas->xa_sibs + 1UL) << xas->xa_shift; +} +#endif + +/* + * Use this to calculate the maximum index that will need to be created + * in order to add the entry described by @xas. Because we cannot store a + * multiple-index entry at index 0, the calculation is a little more complex + * than you might expect. + */ +static unsigned long xas_max(struct xa_state *xas) +{ + unsigned long max = xas->xa_index; + +#ifdef CONFIG_XARRAY_MULTI + if (xas->xa_shift || xas->xa_sibs) { + unsigned long mask = xas_size(xas) - 1; + max |= mask; + if (mask == max) + max++; + } +#endif + + return max; +} + +/* The maximum index that can be contained in the array without expanding it */ +static unsigned long max_index(void *entry) +{ + if (!xa_is_node(entry)) + return 0; + return (XA_CHUNK_SIZE << xa_to_node(entry)->shift) - 1; +} + +static void xas_shrink(struct xa_state *xas) +{ + struct xarray *xa = xas->xa; + struct xa_node *node = xas->xa_node; + + for (;;) { + void *entry; + + XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); + if (node->count != 1) + break; + entry = xa_entry_locked(xa, node, 0); + if (!entry) + break; + if (!xa_is_node(entry) && node->shift) + break; + xas->xa_node = XAS_BOUNDS; + + RCU_INIT_POINTER(xa->xa_head, entry); + if (xa_track_free(xa) && !node_get_mark(node, 0, XA_FREE_MARK)) + xa_mark_clear(xa, XA_FREE_MARK); + + node->count = 0; + node->nr_values = 0; + if (!xa_is_node(entry)) + RCU_INIT_POINTER(node->slots[0], XA_RETRY_ENTRY); + xas_update(xas, node); + xa_node_free(node); + if (!xa_is_node(entry)) + break; + node = xa_to_node(entry); + node->parent = NULL; + } +} + +/* + * xas_delete_node() - Attempt to delete an xa_node + * @xas: Array operation state. + * + * Attempts to delete the @xas->xa_node. This will fail if xa->node has + * a non-zero reference count. + */ +static void xas_delete_node(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + for (;;) { + struct xa_node *parent; + + XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); + if (node->count) + break; + + parent = xa_parent_locked(xas->xa, node); + xas->xa_node = parent; + xas->xa_offset = node->offset; + xa_node_free(node); + + if (!parent) { + xas->xa->xa_head = NULL; + xas->xa_node = XAS_BOUNDS; + return; + } + + parent->slots[xas->xa_offset] = NULL; + parent->count--; + XA_NODE_BUG_ON(parent, parent->count > XA_CHUNK_SIZE); + node = parent; + xas_update(xas, node); + } + + if (!node->parent) + xas_shrink(xas); +} + +/** + * xas_free_nodes() - Free this node and all nodes that it references + * @xas: Array operation state. + * @top: Node to free + * + * This node has been removed from the tree. We must now free it and all + * of its subnodes. There may be RCU walkers with references into the tree, + * so we must replace all entries with retry markers. + */ +static void xas_free_nodes(struct xa_state *xas, struct xa_node *top) +{ + unsigned int offset = 0; + struct xa_node *node = top; + + for (;;) { + void *entry = xa_entry_locked(xas->xa, node, offset); + + if (xa_is_node(entry)) { + node = xa_to_node(entry); + offset = 0; + continue; + } + if (entry) + RCU_INIT_POINTER(node->slots[offset], XA_RETRY_ENTRY); + offset++; + while (offset == XA_CHUNK_SIZE) { + struct xa_node *parent; + + parent = xa_parent_locked(xas->xa, node); + offset = node->offset + 1; + node->count = 0; + node->nr_values = 0; + xas_update(xas, node); + xa_node_free(node); + if (node == top) + return; + node = parent; + } + } +} + +/* + * xas_expand adds nodes to the head of the tree until it has reached + * sufficient height to be able to contain @xas->xa_index + */ +static int xas_expand(struct xa_state *xas, void *head) +{ + struct xarray *xa = xas->xa; + struct xa_node *node = NULL; + unsigned int shift = 0; + unsigned long max = xas_max(xas); + + if (!head) { + if (max == 0) + return 0; + while ((max >> shift) >= XA_CHUNK_SIZE) + shift += XA_CHUNK_SHIFT; + return shift + XA_CHUNK_SHIFT; + } else if (xa_is_node(head)) { + node = xa_to_node(head); + shift = node->shift + XA_CHUNK_SHIFT; + } + xas->xa_node = NULL; + + while (max > max_index(head)) { + xa_mark_t mark = 0; + + XA_NODE_BUG_ON(node, shift > BITS_PER_LONG); + node = xas_alloc(xas, shift); + if (!node) + return -ENOMEM; + + node->count = 1; + if (xa_is_value(head)) + node->nr_values = 1; + RCU_INIT_POINTER(node->slots[0], head); + + /* Propagate the aggregated mark info to the new child */ + for (;;) { + if (xa_track_free(xa) && mark == XA_FREE_MARK) { + node_mark_all(node, XA_FREE_MARK); + if (!xa_marked(xa, XA_FREE_MARK)) { + node_clear_mark(node, 0, XA_FREE_MARK); + xa_mark_set(xa, XA_FREE_MARK); + } + } else if (xa_marked(xa, mark)) { + node_set_mark(node, 0, mark); + } + if (mark == XA_MARK_MAX) + break; + mark_inc(mark); + } + + /* + * Now that the new node is fully initialised, we can add + * it to the tree + */ + if (xa_is_node(head)) { + xa_to_node(head)->offset = 0; + rcu_assign_pointer(xa_to_node(head)->parent, node); + } + head = xa_mk_node(node); + rcu_assign_pointer(xa->xa_head, head); + xas_update(xas, node); + + shift += XA_CHUNK_SHIFT; + } + + xas->xa_node = node; + return shift; +} + +/* + * xas_create() - Create a slot to store an entry in. + * @xas: XArray operation state. + * + * Most users will not need to call this function directly, as it is called + * by xas_store(). It is useful for doing conditional store operations + * (see the xa_cmpxchg() implementation for an example). + * + * Return: If the slot already existed, returns the contents of this slot. + * If the slot was newly created, returns NULL. If it failed to create the + * slot, returns NULL and indicates the error in @xas. + */ +static void *xas_create(struct xa_state *xas) +{ + struct xarray *xa = xas->xa; + void *entry; + void __rcu **slot; + struct xa_node *node = xas->xa_node; + int shift; + unsigned int order = xas->xa_shift; + + if (xas_top(node)) { + entry = xa_head_locked(xa); + xas->xa_node = NULL; + shift = xas_expand(xas, entry); + if (shift < 0) + return NULL; + entry = xa_head_locked(xa); + slot = &xa->xa_head; + } else if (xas_error(xas)) { + return NULL; + } else if (node) { + unsigned int offset = xas->xa_offset; + + shift = node->shift; + entry = xa_entry_locked(xa, node, offset); + slot = &node->slots[offset]; + } else { + shift = 0; + entry = xa_head_locked(xa); + slot = &xa->xa_head; + } + + while (shift > order) { + shift -= XA_CHUNK_SHIFT; + if (!entry) { + node = xas_alloc(xas, shift); + if (!node) + break; + if (xa_track_free(xa)) + node_mark_all(node, XA_FREE_MARK); + rcu_assign_pointer(*slot, xa_mk_node(node)); + } else if (xa_is_node(entry)) { + node = xa_to_node(entry); + } else { + break; + } + entry = xas_descend(xas, node); + slot = &node->slots[xas->xa_offset]; + } + + return entry; +} + +/** + * xas_create_range() - Ensure that stores to this range will succeed + * @xas: XArray operation state. + * + * Creates all of the slots in the range covered by @xas. Sets @xas to + * create single-index entries and positions it at the beginning of the + * range. This is for the benefit of users which have not yet been + * converted to use multi-index entries. + */ +void xas_create_range(struct xa_state *xas) +{ + unsigned long index = xas->xa_index; + unsigned char shift = xas->xa_shift; + unsigned char sibs = xas->xa_sibs; + + xas->xa_index |= ((sibs + 1) << shift) - 1; + if (xas_is_node(xas) && xas->xa_node->shift == xas->xa_shift) + xas->xa_offset |= sibs; + xas->xa_shift = 0; + xas->xa_sibs = 0; + + for (;;) { + xas_create(xas); + if (xas_error(xas)) + goto restore; + if (xas->xa_index <= (index | XA_CHUNK_MASK)) + goto success; + xas->xa_index -= XA_CHUNK_SIZE; + + for (;;) { + struct xa_node *node = xas->xa_node; + xas->xa_node = xa_parent_locked(xas->xa, node); + xas->xa_offset = node->offset - 1; + if (node->offset != 0) + break; + } + } + +restore: + xas->xa_shift = shift; + xas->xa_sibs = sibs; + xas->xa_index = index; + return; +success: + xas->xa_index = index; + if (xas->xa_node) + xas_set_offset(xas); +} +EXPORT_SYMBOL_GPL(xas_create_range); + +static void update_node(struct xa_state *xas, struct xa_node *node, + int count, int values) +{ + if (!node || (!count && !values)) + return; + + node->count += count; + node->nr_values += values; + XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); + XA_NODE_BUG_ON(node, node->nr_values > XA_CHUNK_SIZE); + xas_update(xas, node); + if (count < 0) + xas_delete_node(xas); +} + +/** + * xas_store() - Store this entry in the XArray. + * @xas: XArray operation state. + * @entry: New entry. + * + * If @xas is operating on a multi-index entry, the entry returned by this + * function is essentially meaningless (it may be an internal entry or it + * may be %NULL, even if there are non-NULL entries at some of the indices + * covered by the range). This is not a problem for any current users, + * and can be changed if needed. + * + * Return: The old entry at this index. + */ +void *xas_store(struct xa_state *xas, void *entry) +{ + struct xa_node *node; + void __rcu **slot = &xas->xa->xa_head; + unsigned int offset, max; + int count = 0; + int values = 0; + void *first, *next; + bool value = xa_is_value(entry); + + if (entry) + first = xas_create(xas); + else + first = xas_load(xas); + + if (xas_invalid(xas)) + return first; + node = xas->xa_node; + if (node && (xas->xa_shift < node->shift)) + xas->xa_sibs = 0; + if ((first == entry) && !xas->xa_sibs) + return first; + + next = first; + offset = xas->xa_offset; + max = xas->xa_offset + xas->xa_sibs; + if (node) { + slot = &node->slots[offset]; + if (xas->xa_sibs) + xas_squash_marks(xas); + } + if (!entry) + xas_init_marks(xas); + + for (;;) { + /* + * Must clear the marks before setting the entry to NULL, + * otherwise xas_for_each_marked may find a NULL entry and + * stop early. rcu_assign_pointer contains a release barrier + * so the mark clearing will appear to happen before the + * entry is set to NULL. + */ + rcu_assign_pointer(*slot, entry); + if (xa_is_node(next)) + xas_free_nodes(xas, xa_to_node(next)); + if (!node) + break; + count += !next - !entry; + values += !xa_is_value(first) - !value; + if (entry) { + if (offset == max) + break; + if (!xa_is_sibling(entry)) + entry = xa_mk_sibling(xas->xa_offset); + } else { + if (offset == XA_CHUNK_MASK) + break; + } + next = xa_entry_locked(xas->xa, node, ++offset); + if (!xa_is_sibling(next)) { + if (!entry && (offset > max)) + break; + first = next; + } + slot++; + } + + update_node(xas, node, count, values); + return first; +} +EXPORT_SYMBOL_GPL(xas_store); + +/** + * xas_get_mark() - Returns the state of this mark. + * @xas: XArray operation state. + * @mark: Mark number. + * + * Return: true if the mark is set, false if the mark is clear or @xas + * is in an error state. + */ +bool xas_get_mark(const struct xa_state *xas, xa_mark_t mark) +{ + if (xas_invalid(xas)) + return false; + if (!xas->xa_node) + return xa_marked(xas->xa, mark); + return node_get_mark(xas->xa_node, xas->xa_offset, mark); +} +EXPORT_SYMBOL_GPL(xas_get_mark); + +/** + * xas_set_mark() - Sets the mark on this entry and its parents. + * @xas: XArray operation state. + * @mark: Mark number. + * + * Sets the specified mark on this entry, and walks up the tree setting it + * on all the ancestor entries. Does nothing if @xas has not been walked to + * an entry, or is in an error state. + */ +void xas_set_mark(const struct xa_state *xas, xa_mark_t mark) +{ + struct xa_node *node = xas->xa_node; + unsigned int offset = xas->xa_offset; + + if (xas_invalid(xas)) + return; + + while (node) { + if (node_set_mark(node, offset, mark)) + return; + offset = node->offset; + node = xa_parent_locked(xas->xa, node); + } + + if (!xa_marked(xas->xa, mark)) + xa_mark_set(xas->xa, mark); +} +EXPORT_SYMBOL_GPL(xas_set_mark); + +/** + * xas_clear_mark() - Clears the mark on this entry and its parents. + * @xas: XArray operation state. + * @mark: Mark number. + * + * Clears the specified mark on this entry, and walks back to the head + * attempting to clear it on all the ancestor entries. Does nothing if + * @xas has not been walked to an entry, or is in an error state. + */ +void xas_clear_mark(const struct xa_state *xas, xa_mark_t mark) +{ + struct xa_node *node = xas->xa_node; + unsigned int offset = xas->xa_offset; + + if (xas_invalid(xas)) + return; + + while (node) { + if (!node_clear_mark(node, offset, mark)) + return; + if (node_any_mark(node, mark)) + return; + + offset = node->offset; + node = xa_parent_locked(xas->xa, node); + } + + if (xa_marked(xas->xa, mark)) + xa_mark_clear(xas->xa, mark); +} +EXPORT_SYMBOL_GPL(xas_clear_mark); + +/** + * xas_init_marks() - Initialise all marks for the entry + * @xas: Array operations state. + * + * Initialise all marks for the entry specified by @xas. If we're tracking + * free entries with a mark, we need to set it on all entries. All other + * marks are cleared. + * + * This implementation is not as efficient as it could be; we may walk + * up the tree multiple times. + */ +void xas_init_marks(const struct xa_state *xas) +{ + xa_mark_t mark = 0; + + for (;;) { + if (xa_track_free(xas->xa) && mark == XA_FREE_MARK) + xas_set_mark(xas, mark); + else + xas_clear_mark(xas, mark); + if (mark == XA_MARK_MAX) + break; + mark_inc(mark); + } +} +EXPORT_SYMBOL_GPL(xas_init_marks); + +/** + * xas_pause() - Pause a walk to drop a lock. + * @xas: XArray operation state. + * + * Some users need to pause a walk and drop the lock they're holding in + * order to yield to a higher priority thread or carry out an operation + * on an entry. Those users should call this function before they drop + * the lock. It resets the @xas to be suitable for the next iteration + * of the loop after the user has reacquired the lock. If most entries + * found during a walk require you to call xas_pause(), the xa_for_each() + * iterator may be more appropriate. + * + * Note that xas_pause() only works for forward iteration. If a user needs + * to pause a reverse iteration, we will need a xas_pause_rev(). + */ +void xas_pause(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + if (xas_invalid(xas)) + return; + + if (node) { + unsigned int offset = xas->xa_offset; + while (++offset < XA_CHUNK_SIZE) { + if (!xa_is_sibling(xa_entry(xas->xa, node, offset))) + break; + } + xas->xa_index += (offset - xas->xa_offset) << node->shift; + } else { + xas->xa_index++; + } + xas->xa_node = XAS_RESTART; +} +EXPORT_SYMBOL_GPL(xas_pause); + +/* + * __xas_prev() - Find the previous entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_prev() which handles all the complex cases + * out of line. + */ +void *__xas_prev(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index--; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset--; + + while (xas->xa_offset == 255) { + xas->xa_offset = xas->xa_node->offset - 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas_set_offset(xas); + } +} +EXPORT_SYMBOL_GPL(__xas_prev); + +/* + * __xas_next() - Find the next entry in the XArray. + * @xas: XArray operation state. + * + * Helper function for xas_next() which handles all the complex cases + * out of line. + */ +void *__xas_next(struct xa_state *xas) +{ + void *entry; + + if (!xas_frozen(xas->xa_node)) + xas->xa_index++; + if (xas_not_node(xas->xa_node)) + return xas_load(xas); + + if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node)) + xas->xa_offset++; + + while (xas->xa_offset == XA_CHUNK_SIZE) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + return set_bounds(xas); + } + + for (;;) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + + xas->xa_node = xa_to_node(entry); + xas_set_offset(xas); + } +} +EXPORT_SYMBOL_GPL(__xas_next); + +/** + * xas_find() - Find the next present entry in the XArray. + * @xas: XArray operation state. + * @max: Highest index to return. + * + * If the @xas has not yet been walked to an entry, return the entry + * which has an index >= xas.xa_index. If it has been walked, the entry + * currently being pointed at has been processed, and so we move to the + * next entry. + * + * If no entry is found and the array is smaller than @max, the iterator + * is set to the smallest index not yet in the array. This allows @xas + * to be immediately passed to xas_store(). + * + * Return: The entry, if found, otherwise %NULL. + */ +void *xas_find(struct xa_state *xas, unsigned long max) +{ + void *entry; + + if (xas_error(xas)) + return NULL; + + if (!xas->xa_node) { + xas->xa_index = 1; + return set_bounds(xas); + } else if (xas_top(xas->xa_node)) { + entry = xas_load(xas); + if (entry || xas_not_node(xas->xa_node)) + return entry; + } else if (!xas->xa_node->shift && + xas->xa_offset != (xas->xa_index & XA_CHUNK_MASK)) { + xas->xa_offset = ((xas->xa_index - 1) & XA_CHUNK_MASK) + 1; + } + + xas_advance(xas); + + while (xas->xa_node && (xas->xa_index <= max)) { + if (unlikely(xas->xa_offset == XA_CHUNK_SIZE)) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + continue; + } + + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (xa_is_node(entry)) { + xas->xa_node = xa_to_node(entry); + xas->xa_offset = 0; + continue; + } + if (entry && !xa_is_sibling(entry)) + return entry; + + xas_advance(xas); + } + + if (!xas->xa_node) + xas->xa_node = XAS_BOUNDS; + return NULL; +} +EXPORT_SYMBOL_GPL(xas_find); + +/** + * xas_find_marked() - Find the next marked entry in the XArray. + * @xas: XArray operation state. + * @max: Highest index to return. + * @mark: Mark number to search for. + * + * If the @xas has not yet been walked to an entry, return the marked entry + * which has an index >= xas.xa_index. If it has been walked, the entry + * currently being pointed at has been processed, and so we return the + * first marked entry with an index > xas.xa_index. + * + * If no marked entry is found and the array is smaller than @max, @xas is + * set to the bounds state and xas->xa_index is set to the smallest index + * not yet in the array. This allows @xas to be immediately passed to + * xas_store(). + * + * If no entry is found before @max is reached, @xas is set to the restart + * state. + * + * Return: The entry, if found, otherwise %NULL. + */ +void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark) +{ + bool advance = true; + unsigned int offset; + void *entry; + + if (xas_error(xas)) + return NULL; + + if (!xas->xa_node) { + xas->xa_index = 1; + goto out; + } else if (xas_top(xas->xa_node)) { + advance = false; + entry = xa_head(xas->xa); + xas->xa_node = NULL; + if (xas->xa_index > max_index(entry)) + goto bounds; + if (!xa_is_node(entry)) { + if (xa_marked(xas->xa, mark)) + return entry; + xas->xa_index = 1; + goto out; + } + xas->xa_node = xa_to_node(entry); + xas->xa_offset = xas->xa_index >> xas->xa_node->shift; + } + + while (xas->xa_index <= max) { + if (unlikely(xas->xa_offset == XA_CHUNK_SIZE)) { + xas->xa_offset = xas->xa_node->offset + 1; + xas->xa_node = xa_parent(xas->xa, xas->xa_node); + if (!xas->xa_node) + break; + advance = false; + continue; + } + + if (!advance) { + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (xa_is_sibling(entry)) { + xas->xa_offset = xa_to_sibling(entry); + xas_move_index(xas, xas->xa_offset); + } + } + + offset = xas_find_chunk(xas, advance, mark); + if (offset > xas->xa_offset) { + advance = false; + xas_move_index(xas, offset); + /* Mind the wrap */ + if ((xas->xa_index - 1) >= max) + goto max; + xas->xa_offset = offset; + if (offset == XA_CHUNK_SIZE) + continue; + } + + entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset); + if (!xa_is_node(entry)) + return entry; + xas->xa_node = xa_to_node(entry); + xas_set_offset(xas); + } + +out: + if (!max) + goto max; +bounds: + xas->xa_node = XAS_BOUNDS; + return NULL; +max: + xas->xa_node = XAS_RESTART; + return NULL; +} +EXPORT_SYMBOL_GPL(xas_find_marked); + +/** + * xas_find_conflict() - Find the next present entry in a range. + * @xas: XArray operation state. + * + * The @xas describes both a range and a position within that range. + * + * Context: Any context. Expects xa_lock to be held. + * Return: The next entry in the range covered by @xas or %NULL. + */ +void *xas_find_conflict(struct xa_state *xas) +{ + void *curr; + + if (xas_error(xas)) + return NULL; + + if (!xas->xa_node) + return NULL; + + if (xas_top(xas->xa_node)) { + curr = xas_start(xas); + if (!curr) + return NULL; + while (xa_is_node(curr)) { + struct xa_node *node = xa_to_node(curr); + curr = xas_descend(xas, node); + } + if (curr) + return curr; + } + + if (xas->xa_node->shift > xas->xa_shift) + return NULL; + + for (;;) { + if (xas->xa_node->shift == xas->xa_shift) { + if ((xas->xa_offset & xas->xa_sibs) == xas->xa_sibs) + break; + } else if (xas->xa_offset == XA_CHUNK_MASK) { + xas->xa_offset = xas->xa_node->offset; + xas->xa_node = xa_parent_locked(xas->xa, xas->xa_node); + if (!xas->xa_node) + break; + continue; + } + curr = xa_entry_locked(xas->xa, xas->xa_node, ++xas->xa_offset); + if (xa_is_sibling(curr)) + continue; + while (xa_is_node(curr)) { + xas->xa_node = xa_to_node(curr); + xas->xa_offset = 0; + curr = xa_entry_locked(xas->xa, xas->xa_node, 0); + } + if (curr) + return curr; + } + xas->xa_offset -= xas->xa_sibs; + return NULL; +} +EXPORT_SYMBOL_GPL(xas_find_conflict); + +/** + * xa_init_flags() - Initialise an empty XArray with flags. + * @xa: XArray. + * @flags: XA_FLAG values. + * + * If you need to initialise an XArray with special flags (eg you need + * to take the lock from interrupt context), use this function instead + * of xa_init(). + * + * Context: Any context. + */ +void xa_init_flags(struct xarray *xa, gfp_t flags) +{ + unsigned int lock_type; + static struct lock_class_key xa_lock_irq; + static struct lock_class_key xa_lock_bh; + + spin_lock_init(&xa->xa_lock); + xa->xa_flags = flags; + xa->xa_head = NULL; + + lock_type = xa_lock_type(xa); + if (lock_type == XA_LOCK_IRQ) + lockdep_set_class(&xa->xa_lock, &xa_lock_irq); + else if (lock_type == XA_LOCK_BH) + lockdep_set_class(&xa->xa_lock, &xa_lock_bh); +} +EXPORT_SYMBOL(xa_init_flags); + +/** + * xa_load() - Load an entry from an XArray. + * @xa: XArray. + * @index: index into array. + * + * Context: Any context. Takes and releases the RCU lock. + * Return: The entry at @index in @xa. + */ +void *xa_load(struct xarray *xa, unsigned long index) +{ + XA_STATE(xas, xa, index); + void *entry; + + rcu_read_lock(); + do { + entry = xas_load(&xas); + if (xa_is_zero(entry)) + entry = NULL; + } while (xas_retry(&xas, entry)); + rcu_read_unlock(); + + return entry; +} +EXPORT_SYMBOL(xa_load); + +static void *xas_result(struct xa_state *xas, void *curr) +{ + if (xa_is_zero(curr)) + return NULL; + XA_NODE_BUG_ON(xas->xa_node, xa_is_internal(curr)); + if (xas_error(xas)) + curr = xas->xa_node; + return curr; +} + +/** + * __xa_erase() - Erase this entry from the XArray while locked. + * @xa: XArray. + * @index: Index into array. + * + * If the entry at this index is a multi-index entry then all indices will + * be erased, and the entry will no longer be a multi-index entry. + * This function expects the xa_lock to be held on entry. + * + * Context: Any context. Expects xa_lock to be held on entry. May + * release and reacquire xa_lock if @gfp flags permit. + * Return: The old entry at this index. + */ +void *__xa_erase(struct xarray *xa, unsigned long index) +{ + XA_STATE(xas, xa, index); + return xas_result(&xas, xas_store(&xas, NULL)); +} +EXPORT_SYMBOL_GPL(__xa_erase); + +/** + * xa_store() - Store this entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * After this function returns, loads from this index will return @entry. + * Storing into an existing multislot entry updates the entry of every index. + * The marks associated with @index are unaffected unless @entry is %NULL. + * + * Context: Process context. Takes and releases the xa_lock. May sleep + * if the @gfp flags permit. + * Return: The old entry at this index on success, xa_err(-EINVAL) if @entry + * cannot be stored in an XArray, or xa_err(-ENOMEM) if memory allocation + * failed. + */ +void *xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, index); + void *curr; + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return XA_ERROR(-EINVAL); + + do { + xas_lock(&xas); + curr = xas_store(&xas, entry); + if (xa_track_free(xa) && entry) + xas_clear_mark(&xas, XA_FREE_MARK); + xas_unlock(&xas); + } while (xas_nomem(&xas, gfp)); + + return xas_result(&xas, curr); +} +EXPORT_SYMBOL(xa_store); + +/** + * __xa_store() - Store this entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * You must already be holding the xa_lock when calling this function. + * It will drop the lock if needed to allocate memory, and then reacquire + * it afterwards. + * + * Context: Any context. Expects xa_lock to be held on entry. May + * release and reacquire xa_lock if @gfp flags permit. + * Return: The old entry at this index or xa_err() if an error happened. + */ +void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, index); + void *curr; + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return XA_ERROR(-EINVAL); + + do { + curr = xas_store(&xas, entry); + if (xa_track_free(xa) && entry) + xas_clear_mark(&xas, XA_FREE_MARK); + } while (__xas_nomem(&xas, gfp)); + + return xas_result(&xas, curr); +} +EXPORT_SYMBOL(__xa_store); + +/** + * xa_cmpxchg() - Conditionally replace an entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @old: Old value to test against. + * @entry: New value to place in array. + * @gfp: Memory allocation flags. + * + * If the entry at @index is the same as @old, replace it with @entry. + * If the return value is equal to @old, then the exchange was successful. + * + * Context: Process context. Takes and releases the xa_lock. May sleep + * if the @gfp flags permit. + * Return: The old value at this index or xa_err() if an error happened. + */ +void *xa_cmpxchg(struct xarray *xa, unsigned long index, + void *old, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, index); + void *curr; + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return XA_ERROR(-EINVAL); + + do { + xas_lock(&xas); + curr = xas_load(&xas); + if (curr == XA_ZERO_ENTRY) + curr = NULL; + if (curr == old) { + xas_store(&xas, entry); + if (xa_track_free(xa) && entry) + xas_clear_mark(&xas, XA_FREE_MARK); + } + xas_unlock(&xas); + } while (xas_nomem(&xas, gfp)); + + return xas_result(&xas, curr); +} +EXPORT_SYMBOL(xa_cmpxchg); + +/** + * __xa_cmpxchg() - Store this entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @old: Old value to test against. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * You must already be holding the xa_lock when calling this function. + * It will drop the lock if needed to allocate memory, and then reacquire + * it afterwards. + * + * Context: Any context. Expects xa_lock to be held on entry. May + * release and reacquire xa_lock if @gfp flags permit. + * Return: The old entry at this index or xa_err() if an error happened. + */ +void *__xa_cmpxchg(struct xarray *xa, unsigned long index, + void *old, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, index); + void *curr; + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return XA_ERROR(-EINVAL); + + do { + curr = xas_load(&xas); + if (curr == XA_ZERO_ENTRY) + curr = NULL; + if (curr == old) { + xas_store(&xas, entry); + if (xa_track_free(xa) && entry) + xas_clear_mark(&xas, XA_FREE_MARK); + } + } while (__xas_nomem(&xas, gfp)); + + return xas_result(&xas, curr); +} +EXPORT_SYMBOL(__xa_cmpxchg); + +/** + * xa_reserve() - Reserve this index in the XArray. + * @xa: XArray. + * @index: Index into array. + * @gfp: Memory allocation flags. + * + * Ensures there is somewhere to store an entry at @index in the array. + * If there is already something stored at @index, this function does + * nothing. If there was nothing there, the entry is marked as reserved. + * Loads from @index will continue to see a %NULL pointer until a + * subsequent store to @index. + * + * If you do not use the entry that you have reserved, call xa_release() + * or xa_erase() to free any unnecessary memory. + * + * Context: Process context. Takes and releases the xa_lock, IRQ or BH safe + * if specified in XArray flags. May sleep if the @gfp flags permit. + * Return: 0 if the reservation succeeded or -ENOMEM if it failed. + */ +int xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp) +{ + XA_STATE(xas, xa, index); + unsigned int lock_type = xa_lock_type(xa); + void *curr; + + do { + xas_lock_type(&xas, lock_type); + curr = xas_load(&xas); + if (!curr) + xas_store(&xas, XA_ZERO_ENTRY); + xas_unlock_type(&xas, lock_type); + } while (xas_nomem(&xas, gfp)); + + return xas_error(&xas); +} +EXPORT_SYMBOL(xa_reserve); + +#ifdef CONFIG_XARRAY_MULTI +static void xas_set_range(struct xa_state *xas, unsigned long first, + unsigned long last) +{ + unsigned int shift = 0; + unsigned long sibs = last - first; + unsigned int offset = XA_CHUNK_MASK; + + xas_set(xas, first); + + while ((first & XA_CHUNK_MASK) == 0) { + if (sibs < XA_CHUNK_MASK) + break; + if ((sibs == XA_CHUNK_MASK) && (offset < XA_CHUNK_MASK)) + break; + shift += XA_CHUNK_SHIFT; + if (offset == XA_CHUNK_MASK) + offset = sibs & XA_CHUNK_MASK; + sibs >>= XA_CHUNK_SHIFT; + first >>= XA_CHUNK_SHIFT; + } + + offset = first & XA_CHUNK_MASK; + if (offset + sibs > XA_CHUNK_MASK) + sibs = XA_CHUNK_MASK - offset; + if ((((first + sibs + 1) << shift) - 1) > last) + sibs -= 1; + + xas->xa_shift = shift; + xas->xa_sibs = sibs; +} + +/** + * xa_store_range() - Store this entry at a range of indices in the XArray. + * @xa: XArray. + * @first: First index to affect. + * @last: Last index to affect. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * After this function returns, loads from any index between @first and @last, + * inclusive will return @entry. + * Storing into an existing multislot entry updates the entry of every index. + * The marks associated with @index are unaffected unless @entry is %NULL. + * + * Context: Process context. Takes and releases the xa_lock. May sleep + * if the @gfp flags permit. + * Return: %NULL on success, xa_err(-EINVAL) if @entry cannot be stored in + * an XArray, or xa_err(-ENOMEM) if memory allocation failed. + */ +void *xa_store_range(struct xarray *xa, unsigned long first, + unsigned long last, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, 0); + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return XA_ERROR(-EINVAL); + if (last < first) + return XA_ERROR(-EINVAL); + + do { + xas_lock(&xas); + if (entry) { + unsigned int order = (last == ~0UL) ? 64 : + ilog2(last + 1); + xas_set_order(&xas, last, order); + xas_create(&xas); + if (xas_error(&xas)) + goto unlock; + } + do { + xas_set_range(&xas, first, last); + xas_store(&xas, entry); + if (xas_error(&xas)) + goto unlock; + first += xas_size(&xas); + } while (first <= last); +unlock: + xas_unlock(&xas); + } while (xas_nomem(&xas, gfp)); + + return xas_result(&xas, NULL); +} +EXPORT_SYMBOL(xa_store_range); +#endif /* CONFIG_XARRAY_MULTI */ + +/** + * __xa_alloc() - Find somewhere to store this entry in the XArray. + * @xa: XArray. + * @id: Pointer to ID. + * @max: Maximum ID to allocate (inclusive). + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * Allocates an unused ID in the range specified by @id and @max. + * Updates the @id pointer with the index, then stores the entry at that + * index. A concurrent lookup will not see an uninitialised @id. + * + * Context: Any context. Expects xa_lock to be held on entry. May + * release and reacquire xa_lock if @gfp flags permit. + * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if + * there is no more space in the XArray. + */ +int __xa_alloc(struct xarray *xa, u32 *id, u32 max, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, 0); + int err; + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return -EINVAL; + if (WARN_ON_ONCE(!xa_track_free(xa))) + return -EINVAL; + + if (!entry) + entry = XA_ZERO_ENTRY; + + do { + xas.xa_index = *id; + xas_find_marked(&xas, max, XA_FREE_MARK); + if (xas.xa_node == XAS_RESTART) + xas_set_err(&xas, -ENOSPC); + xas_store(&xas, entry); + xas_clear_mark(&xas, XA_FREE_MARK); + } while (__xas_nomem(&xas, gfp)); + + err = xas_error(&xas); + if (!err) + *id = xas.xa_index; + return err; +} +EXPORT_SYMBOL(__xa_alloc); + +/** + * __xa_set_mark() - Set this mark on this entry while locked. + * @xa: XArray. + * @index: Index of entry. + * @mark: Mark number. + * + * Attempting to set a mark on a NULL entry does not succeed. + * + * Context: Any context. Expects xa_lock to be held on entry. + */ +void __xa_set_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) +{ + XA_STATE(xas, xa, index); + void *entry = xas_load(&xas); + + if (entry) + xas_set_mark(&xas, mark); +} +EXPORT_SYMBOL_GPL(__xa_set_mark); + +/** + * __xa_clear_mark() - Clear this mark on this entry while locked. + * @xa: XArray. + * @index: Index of entry. + * @mark: Mark number. + * + * Context: Any context. Expects xa_lock to be held on entry. + */ +void __xa_clear_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) +{ + XA_STATE(xas, xa, index); + void *entry = xas_load(&xas); + + if (entry) + xas_clear_mark(&xas, mark); +} +EXPORT_SYMBOL_GPL(__xa_clear_mark); + +/** + * xa_get_mark() - Inquire whether this mark is set on this entry. + * @xa: XArray. + * @index: Index of entry. + * @mark: Mark number. + * + * This function uses the RCU read lock, so the result may be out of date + * by the time it returns. If you need the result to be stable, use a lock. + * + * Context: Any context. Takes and releases the RCU lock. + * Return: True if the entry at @index has this mark set, false if it doesn't. + */ +bool xa_get_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) +{ + XA_STATE(xas, xa, index); + void *entry; + + rcu_read_lock(); + entry = xas_start(&xas); + while (xas_get_mark(&xas, mark)) { + if (!xa_is_node(entry)) + goto found; + entry = xas_descend(&xas, xa_to_node(entry)); + } + rcu_read_unlock(); + return false; + found: + rcu_read_unlock(); + return true; +} +EXPORT_SYMBOL(xa_get_mark); + +/** + * xa_set_mark() - Set this mark on this entry. + * @xa: XArray. + * @index: Index of entry. + * @mark: Mark number. + * + * Attempting to set a mark on a NULL entry does not succeed. + * + * Context: Process context. Takes and releases the xa_lock. + */ +void xa_set_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) +{ + xa_lock(xa); + __xa_set_mark(xa, index, mark); + xa_unlock(xa); +} +EXPORT_SYMBOL(xa_set_mark); + +/** + * xa_clear_mark() - Clear this mark on this entry. + * @xa: XArray. + * @index: Index of entry. + * @mark: Mark number. + * + * Clearing a mark always succeeds. + * + * Context: Process context. Takes and releases the xa_lock. + */ +void xa_clear_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) +{ + xa_lock(xa); + __xa_clear_mark(xa, index, mark); + xa_unlock(xa); +} +EXPORT_SYMBOL(xa_clear_mark); + +/** + * xa_find() - Search the XArray for an entry. + * @xa: XArray. + * @indexp: Pointer to an index. + * @max: Maximum index to search to. + * @filter: Selection criterion. + * + * Finds the entry in @xa which matches the @filter, and has the lowest + * index that is at least @indexp and no more than @max. + * If an entry is found, @indexp is updated to be the index of the entry. + * This function is protected by the RCU read lock, so it may not find + * entries which are being simultaneously added. It will not return an + * %XA_RETRY_ENTRY; if you need to see retry entries, use xas_find(). + * + * Context: Any context. Takes and releases the RCU lock. + * Return: The entry, if found, otherwise %NULL. + */ +void *xa_find(struct xarray *xa, unsigned long *indexp, + unsigned long max, xa_mark_t filter) +{ + XA_STATE(xas, xa, *indexp); + void *entry; + + rcu_read_lock(); + do { + if ((__force unsigned int)filter < XA_MAX_MARKS) + entry = xas_find_marked(&xas, max, filter); + else + entry = xas_find(&xas, max); + } while (xas_retry(&xas, entry)); + rcu_read_unlock(); + + if (entry) + *indexp = xas.xa_index; + return entry; +} +EXPORT_SYMBOL(xa_find); + +/** + * xa_find_after() - Search the XArray for a present entry. + * @xa: XArray. + * @indexp: Pointer to an index. + * @max: Maximum index to search to. + * @filter: Selection criterion. + * + * Finds the entry in @xa which matches the @filter and has the lowest + * index that is above @indexp and no more than @max. + * If an entry is found, @indexp is updated to be the index of the entry. + * This function is protected by the RCU read lock, so it may miss entries + * which are being simultaneously added. It will not return an + * %XA_RETRY_ENTRY; if you need to see retry entries, use xas_find(). + * + * Context: Any context. Takes and releases the RCU lock. + * Return: The pointer, if found, otherwise %NULL. + */ +void *xa_find_after(struct xarray *xa, unsigned long *indexp, + unsigned long max, xa_mark_t filter) +{ + XA_STATE(xas, xa, *indexp + 1); + void *entry; + + rcu_read_lock(); + for (;;) { + if ((__force unsigned int)filter < XA_MAX_MARKS) + entry = xas_find_marked(&xas, max, filter); + else + entry = xas_find(&xas, max); + if (xas.xa_shift) { + if (xas.xa_index & ((1UL << xas.xa_shift) - 1)) + continue; + } else { + if (xas.xa_offset < (xas.xa_index & XA_CHUNK_MASK)) + continue; + } + if (!xas_retry(&xas, entry)) + break; + } + rcu_read_unlock(); + + if (entry) + *indexp = xas.xa_index; + return entry; +} +EXPORT_SYMBOL(xa_find_after); + +static unsigned int xas_extract_present(struct xa_state *xas, void **dst, + unsigned long max, unsigned int n) +{ + void *entry; + unsigned int i = 0; + + rcu_read_lock(); + xas_for_each(xas, entry, max) { + if (xas_retry(xas, entry)) + continue; + dst[i++] = entry; + if (i == n) + break; + } + rcu_read_unlock(); + + return i; +} + +static unsigned int xas_extract_marked(struct xa_state *xas, void **dst, + unsigned long max, unsigned int n, xa_mark_t mark) +{ + void *entry; + unsigned int i = 0; + + rcu_read_lock(); + xas_for_each_marked(xas, entry, max, mark) { + if (xas_retry(xas, entry)) + continue; + dst[i++] = entry; + if (i == n) + break; + } + rcu_read_unlock(); + + return i; +} + +/** + * xa_extract() - Copy selected entries from the XArray into a normal array. + * @xa: The source XArray to copy from. + * @dst: The buffer to copy entries into. + * @start: The first index in the XArray eligible to be selected. + * @max: The last index in the XArray eligible to be selected. + * @n: The maximum number of entries to copy. + * @filter: Selection criterion. + * + * Copies up to @n entries that match @filter from the XArray. The + * copied entries will have indices between @start and @max, inclusive. + * + * The @filter may be an XArray mark value, in which case entries which are + * marked with that mark will be copied. It may also be %XA_PRESENT, in + * which case all entries which are not NULL will be copied. + * + * The entries returned may not represent a snapshot of the XArray at a + * moment in time. For example, if another thread stores to index 5, then + * index 10, calling xa_extract() may return the old contents of index 5 + * and the new contents of index 10. Indices not modified while this + * function is running will not be skipped. + * + * If you need stronger guarantees, holding the xa_lock across calls to this + * function will prevent concurrent modification. + * + * Context: Any context. Takes and releases the RCU lock. + * Return: The number of entries copied. + */ +unsigned int xa_extract(struct xarray *xa, void **dst, unsigned long start, + unsigned long max, unsigned int n, xa_mark_t filter) +{ + XA_STATE(xas, xa, start); + + if (!n) + return 0; + + if ((__force unsigned int)filter < XA_MAX_MARKS) + return xas_extract_marked(&xas, dst, max, n, filter); + return xas_extract_present(&xas, dst, max, n); +} +EXPORT_SYMBOL(xa_extract); + +/** + * xa_destroy() - Free all internal data structures. + * @xa: XArray. + * + * After calling this function, the XArray is empty and has freed all memory + * allocated for its internal data structures. You are responsible for + * freeing the objects referenced by the XArray. + * + * Context: Any context. Takes and releases the xa_lock, interrupt-safe. + */ +void xa_destroy(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + unsigned long flags; + void *entry; + + xas.xa_node = NULL; + xas_lock_irqsave(&xas, flags); + entry = xa_head_locked(xa); + RCU_INIT_POINTER(xa->xa_head, NULL); + xas_init_marks(&xas); + /* lockdep checks we're still holding the lock in xas_free_nodes() */ + if (xa_is_node(entry)) + xas_free_nodes(&xas, xa_to_node(entry)); + xas_unlock_irqrestore(&xas, flags); +} +EXPORT_SYMBOL(xa_destroy); + +#ifdef XA_DEBUG +void xa_dump_node(const struct xa_node *node) +{ + unsigned i, j; + + if (!node) + return; + if ((unsigned long)node & 3) { + pr_cont("node %px\n", node); + return; + } + + pr_cont("node %px %s %d parent %px shift %d count %d values %d " + "array %px list %px %px marks", + node, node->parent ? "offset" : "max", node->offset, + node->parent, node->shift, node->count, node->nr_values, + node->array, node->private_list.prev, node->private_list.next); + for (i = 0; i < XA_MAX_MARKS; i++) + for (j = 0; j < XA_MARK_LONGS; j++) + pr_cont(" %lx", node->marks[i][j]); + pr_cont("\n"); +} + +void xa_dump_index(unsigned long index, unsigned int shift) +{ + if (!shift) + pr_info("%lu: ", index); + else if (shift >= BITS_PER_LONG) + pr_info("0-%lu: ", ~0UL); + else + pr_info("%lu-%lu: ", index, index | ((1UL << shift) - 1)); +} + +void xa_dump_entry(const void *entry, unsigned long index, unsigned long shift) +{ + if (!entry) + return; + + xa_dump_index(index, shift); + + if (xa_is_node(entry)) { + if (shift == 0) { + pr_cont("%px\n", entry); + } else { + unsigned long i; + struct xa_node *node = xa_to_node(entry); + xa_dump_node(node); + for (i = 0; i < XA_CHUNK_SIZE; i++) + xa_dump_entry(node->slots[i], + index + (i << node->shift), node->shift); + } + } else if (xa_is_value(entry)) + pr_cont("value %ld (0x%lx) [%px]\n", xa_to_value(entry), + xa_to_value(entry), entry); + else if (!xa_is_internal(entry)) + pr_cont("%px\n", entry); + else if (xa_is_retry(entry)) + pr_cont("retry (%ld)\n", xa_to_internal(entry)); + else if (xa_is_sibling(entry)) + pr_cont("sibling (slot %ld)\n", xa_to_sibling(entry)); + else if (xa_is_zero(entry)) + pr_cont("zero (%ld)\n", xa_to_internal(entry)); + else + pr_cont("UNKNOWN ENTRY (%px)\n", entry); +} + +void xa_dump(const struct xarray *xa) +{ + void *entry = xa->xa_head; + unsigned int shift = 0; + + pr_info("xarray: %px head %px flags %x marks %d %d %d\n", xa, entry, + xa->xa_flags, xa_marked(xa, XA_MARK_0), + xa_marked(xa, XA_MARK_1), xa_marked(xa, XA_MARK_2)); + if (xa_is_node(entry)) + shift = xa_to_node(entry)->shift + XA_CHUNK_SHIFT; + xa_dump_entry(entry, 0, shift); +} +#endif diff --git a/mm/Kconfig b/mm/Kconfig index de64ea658716..02301a89089e 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -379,7 +379,7 @@ config TRANSPARENT_HUGEPAGE bool "Transparent Hugepage Support" depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE select COMPACTION - select RADIX_TREE_MULTIORDER + select XARRAY_MULTI help Transparent Hugepages allows the kernel to use huge pages and huge tlb transparently to the applications whenever possible. @@ -671,7 +671,7 @@ config ZONE_DEVICE depends on MEMORY_HOTREMOVE depends on SPARSEMEM_VMEMMAP depends on ARCH_HAS_ZONE_DEVICE - select RADIX_TREE_MULTIORDER + select XARRAY_MULTI help Device memory hotplug support allows for establishing pmem, diff --git a/mm/filemap.c b/mm/filemap.c index 3968da1f7f5a..218d0b2ec82d 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -113,60 +113,26 @@ * ->tasklist_lock (memory_failure, collect_procs_ao) */ -static int page_cache_tree_insert(struct address_space *mapping, - struct page *page, void **shadowp) -{ - struct radix_tree_node *node; - void **slot; - int error; - - error = __radix_tree_create(&mapping->i_pages, page->index, 0, - &node, &slot); - if (error) - return error; - if (*slot) { - void *p; - - p = radix_tree_deref_slot_protected(slot, - &mapping->i_pages.xa_lock); - if (!radix_tree_exceptional_entry(p)) - return -EEXIST; - - mapping->nrexceptional--; - if (shadowp) - *shadowp = p; - } - __radix_tree_replace(&mapping->i_pages, node, slot, page, - workingset_lookup_update(mapping)); - mapping->nrpages++; - return 0; -} - -static void page_cache_tree_delete(struct address_space *mapping, +static void page_cache_delete(struct address_space *mapping, struct page *page, void *shadow) { - int i, nr; + XA_STATE(xas, &mapping->i_pages, page->index); + unsigned int nr = 1; - /* hugetlb pages are represented by one entry in the radix tree */ - nr = PageHuge(page) ? 1 : hpage_nr_pages(page); + mapping_set_update(&xas, mapping); + + /* hugetlb pages are represented by a single entry in the xarray */ + if (!PageHuge(page)) { + xas_set_order(&xas, page->index, compound_order(page)); + nr = 1U << compound_order(page); + } VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageTail(page), page); VM_BUG_ON_PAGE(nr != 1 && shadow, page); - for (i = 0; i < nr; i++) { - struct radix_tree_node *node; - void **slot; - - __radix_tree_lookup(&mapping->i_pages, page->index + i, - &node, &slot); - - VM_BUG_ON_PAGE(!node && nr != 1, page); - - radix_tree_clear_tags(&mapping->i_pages, node, slot); - __radix_tree_replace(&mapping->i_pages, node, slot, shadow, - workingset_lookup_update(mapping)); - } + xas_store(&xas, shadow); + xas_init_marks(&xas); page->mapping = NULL; /* Leave page->index set: truncation lookup relies upon it */ @@ -265,7 +231,7 @@ void __delete_from_page_cache(struct page *page, void *shadow) trace_mm_filemap_delete_from_page_cache(page); unaccount_page_cache_page(mapping, page); - page_cache_tree_delete(mapping, page, shadow); + page_cache_delete(mapping, page, shadow); } static void page_cache_free_page(struct address_space *mapping, @@ -308,7 +274,7 @@ void delete_from_page_cache(struct page *page) EXPORT_SYMBOL(delete_from_page_cache); /* - * page_cache_tree_delete_batch - delete several pages from page cache + * page_cache_delete_batch - delete several pages from page cache * @mapping: the mapping to which pages belong * @pvec: pagevec with pages to delete * @@ -321,24 +287,19 @@ EXPORT_SYMBOL(delete_from_page_cache); * * The function expects the i_pages lock to be held. */ -static void -page_cache_tree_delete_batch(struct address_space *mapping, +static void page_cache_delete_batch(struct address_space *mapping, struct pagevec *pvec) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, pvec->pages[0]->index); int total_pages = 0; int i = 0, tail_pages = 0; struct page *page; - pgoff_t start; - start = pvec->pages[0]->index; - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { + mapping_set_update(&xas, mapping); + xas_for_each(&xas, page, ULONG_MAX) { if (i >= pagevec_count(pvec) && !tail_pages) break; - page = radix_tree_deref_slot_protected(slot, - &mapping->i_pages.xa_lock); - if (radix_tree_exceptional_entry(page)) + if (xa_is_value(page)) continue; if (!tail_pages) { /* @@ -346,8 +307,11 @@ page_cache_tree_delete_batch(struct address_space *mapping, * have our pages locked so they are protected from * being removed. */ - if (page != pvec->pages[i]) + if (page != pvec->pages[i]) { + VM_BUG_ON_PAGE(page->index > + pvec->pages[i]->index, page); continue; + } WARN_ON_ONCE(!PageLocked(page)); if (PageTransHuge(page) && !PageHuge(page)) tail_pages = HPAGE_PMD_NR - 1; @@ -358,11 +322,11 @@ page_cache_tree_delete_batch(struct address_space *mapping, */ i++; } else { + VM_BUG_ON_PAGE(page->index + HPAGE_PMD_NR - tail_pages + != pvec->pages[i]->index, page); tail_pages--; } - radix_tree_clear_tags(&mapping->i_pages, iter.node, slot); - __radix_tree_replace(&mapping->i_pages, iter.node, slot, NULL, - workingset_lookup_update(mapping)); + xas_store(&xas, NULL); total_pages++; } mapping->nrpages -= total_pages; @@ -383,7 +347,7 @@ void delete_from_page_cache_batch(struct address_space *mapping, unaccount_page_cache_page(mapping, pvec->pages[i]); } - page_cache_tree_delete_batch(mapping, pvec); + page_cache_delete_batch(mapping, pvec); xa_unlock_irqrestore(&mapping->i_pages, flags); for (i = 0; i < pagevec_count(pvec); i++) @@ -493,20 +457,31 @@ EXPORT_SYMBOL(filemap_flush); bool filemap_range_has_page(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { - pgoff_t index = start_byte >> PAGE_SHIFT; - pgoff_t end = end_byte >> PAGE_SHIFT; struct page *page; + XA_STATE(xas, &mapping->i_pages, start_byte >> PAGE_SHIFT); + pgoff_t max = end_byte >> PAGE_SHIFT; if (end_byte < start_byte) return false; - if (mapping->nrpages == 0) - return false; + rcu_read_lock(); + for (;;) { + page = xas_find(&xas, max); + if (xas_retry(&xas, page)) + continue; + /* Shadow entries don't count */ + if (xa_is_value(page)) + continue; + /* + * We don't need to try to pin this page; we're about to + * release the RCU lock anyway. It is enough to know that + * there was a page here recently. + */ + break; + } + rcu_read_unlock(); - if (!find_get_pages_range(mapping, &index, end, 1, &page)) - return false; - put_page(page); - return true; + return page != NULL; } EXPORT_SYMBOL(filemap_range_has_page); @@ -777,51 +752,44 @@ EXPORT_SYMBOL(file_write_and_wait_range); * locked. This function does not add the new page to the LRU, the * caller must do that. * - * The remove + add is atomic. The only way this function can fail is - * memory allocation failure. + * The remove + add is atomic. This function cannot fail. */ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) { - int error; + struct address_space *mapping = old->mapping; + void (*freepage)(struct page *) = mapping->a_ops->freepage; + pgoff_t offset = old->index; + XA_STATE(xas, &mapping->i_pages, offset); + unsigned long flags; VM_BUG_ON_PAGE(!PageLocked(old), old); VM_BUG_ON_PAGE(!PageLocked(new), new); VM_BUG_ON_PAGE(new->mapping, new); - error = radix_tree_preload(gfp_mask & GFP_RECLAIM_MASK); - if (!error) { - struct address_space *mapping = old->mapping; - void (*freepage)(struct page *); - unsigned long flags; + get_page(new); + new->mapping = mapping; + new->index = offset; - pgoff_t offset = old->index; - freepage = mapping->a_ops->freepage; + xas_lock_irqsave(&xas, flags); + xas_store(&xas, new); - get_page(new); - new->mapping = mapping; - new->index = offset; + old->mapping = NULL; + /* hugetlb pages do not participate in page cache accounting. */ + if (!PageHuge(old)) + __dec_node_page_state(new, NR_FILE_PAGES); + if (!PageHuge(new)) + __inc_node_page_state(new, NR_FILE_PAGES); + if (PageSwapBacked(old)) + __dec_node_page_state(new, NR_SHMEM); + if (PageSwapBacked(new)) + __inc_node_page_state(new, NR_SHMEM); + xas_unlock_irqrestore(&xas, flags); + mem_cgroup_migrate(old, new); + if (freepage) + freepage(old); + put_page(old); - xa_lock_irqsave(&mapping->i_pages, flags); - __delete_from_page_cache(old, NULL); - error = page_cache_tree_insert(mapping, new, NULL); - BUG_ON(error); - - /* - * hugetlb pages do not participate in page cache accounting. - */ - if (!PageHuge(new)) - __inc_node_page_state(new, NR_FILE_PAGES); - if (PageSwapBacked(new)) - __inc_node_page_state(new, NR_SHMEM); - xa_unlock_irqrestore(&mapping->i_pages, flags); - mem_cgroup_migrate(old, new); - radix_tree_preload_end(); - if (freepage) - freepage(old); - put_page(old); - } - - return error; + return 0; } EXPORT_SYMBOL_GPL(replace_page_cache_page); @@ -830,12 +798,15 @@ static int __add_to_page_cache_locked(struct page *page, pgoff_t offset, gfp_t gfp_mask, void **shadowp) { + XA_STATE(xas, &mapping->i_pages, offset); int huge = PageHuge(page); struct mem_cgroup *memcg; int error; + void *old; VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageSwapBacked(page), page); + mapping_set_update(&xas, mapping); if (!huge) { error = mem_cgroup_try_charge(page, current->mm, @@ -844,39 +815,47 @@ static int __add_to_page_cache_locked(struct page *page, return error; } - error = radix_tree_maybe_preload(gfp_mask & GFP_RECLAIM_MASK); - if (error) { - if (!huge) - mem_cgroup_cancel_charge(page, memcg, false); - return error; - } - get_page(page); page->mapping = mapping; page->index = offset; - xa_lock_irq(&mapping->i_pages); - error = page_cache_tree_insert(mapping, page, shadowp); - radix_tree_preload_end(); - if (unlikely(error)) - goto err_insert; + do { + xas_lock_irq(&xas); + old = xas_load(&xas); + if (old && !xa_is_value(old)) + xas_set_err(&xas, -EEXIST); + xas_store(&xas, page); + if (xas_error(&xas)) + goto unlock; + + if (xa_is_value(old)) { + mapping->nrexceptional--; + if (shadowp) + *shadowp = old; + } + mapping->nrpages++; + + /* hugetlb pages do not participate in page cache accounting */ + if (!huge) + __inc_node_page_state(page, NR_FILE_PAGES); +unlock: + xas_unlock_irq(&xas); + } while (xas_nomem(&xas, gfp_mask & GFP_RECLAIM_MASK)); + + if (xas_error(&xas)) + goto error; - /* hugetlb pages do not participate in page cache accounting. */ - if (!huge) - __inc_node_page_state(page, NR_FILE_PAGES); - xa_unlock_irq(&mapping->i_pages); if (!huge) mem_cgroup_commit_charge(page, memcg, false, false); trace_mm_filemap_add_to_page_cache(page); return 0; -err_insert: +error: page->mapping = NULL; /* Leave page->index set: truncation relies upon it */ - xa_unlock_irq(&mapping->i_pages); if (!huge) mem_cgroup_cancel_charge(page, memcg, false); put_page(page); - return error; + return xas_error(&xas); } /** @@ -1341,86 +1320,76 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm, } /** - * page_cache_next_hole - find the next hole (not-present entry) - * @mapping: mapping - * @index: index - * @max_scan: maximum range to search + * page_cache_next_miss() - Find the next gap in the page cache. + * @mapping: Mapping. + * @index: Index. + * @max_scan: Maximum range to search. * - * Search the set [index, min(index+max_scan-1, MAX_INDEX)] for the - * lowest indexed hole. + * Search the range [index, min(index + max_scan - 1, ULONG_MAX)] for the + * gap with the lowest index. * - * Returns: the index of the hole if found, otherwise returns an index - * outside of the set specified (in which case 'return - index >= - * max_scan' will be true). In rare cases of index wrap-around, 0 will - * be returned. + * This function may be called under the rcu_read_lock. However, this will + * not atomically search a snapshot of the cache at a single point in time. + * For example, if a gap is created at index 5, then subsequently a gap is + * created at index 10, page_cache_next_miss covering both indices may + * return 10 if called under the rcu_read_lock. * - * page_cache_next_hole may be called under rcu_read_lock. However, - * like radix_tree_gang_lookup, this will not atomically search a - * snapshot of the tree at a single point in time. For example, if a - * hole is created at index 5, then subsequently a hole is created at - * index 10, page_cache_next_hole covering both indexes may return 10 - * if called under rcu_read_lock. + * Return: The index of the gap if found, otherwise an index outside the + * range specified (in which case 'return - index >= max_scan' will be true). + * In the rare case of index wrap-around, 0 will be returned. */ -pgoff_t page_cache_next_hole(struct address_space *mapping, +pgoff_t page_cache_next_miss(struct address_space *mapping, pgoff_t index, unsigned long max_scan) { - unsigned long i; + XA_STATE(xas, &mapping->i_pages, index); - for (i = 0; i < max_scan; i++) { - struct page *page; - - page = radix_tree_lookup(&mapping->i_pages, index); - if (!page || radix_tree_exceptional_entry(page)) + while (max_scan--) { + void *entry = xas_next(&xas); + if (!entry || xa_is_value(entry)) break; - index++; - if (index == 0) + if (xas.xa_index == 0) break; } - return index; + return xas.xa_index; } -EXPORT_SYMBOL(page_cache_next_hole); +EXPORT_SYMBOL(page_cache_next_miss); /** - * page_cache_prev_hole - find the prev hole (not-present entry) - * @mapping: mapping - * @index: index - * @max_scan: maximum range to search + * page_cache_prev_miss() - Find the next gap in the page cache. + * @mapping: Mapping. + * @index: Index. + * @max_scan: Maximum range to search. * - * Search backwards in the range [max(index-max_scan+1, 0), index] for - * the first hole. + * Search the range [max(index - max_scan + 1, 0), index] for the + * gap with the highest index. * - * Returns: the index of the hole if found, otherwise returns an index - * outside of the set specified (in which case 'index - return >= - * max_scan' will be true). In rare cases of wrap-around, ULONG_MAX - * will be returned. + * This function may be called under the rcu_read_lock. However, this will + * not atomically search a snapshot of the cache at a single point in time. + * For example, if a gap is created at index 10, then subsequently a gap is + * created at index 5, page_cache_prev_miss() covering both indices may + * return 5 if called under the rcu_read_lock. * - * page_cache_prev_hole may be called under rcu_read_lock. However, - * like radix_tree_gang_lookup, this will not atomically search a - * snapshot of the tree at a single point in time. For example, if a - * hole is created at index 10, then subsequently a hole is created at - * index 5, page_cache_prev_hole covering both indexes may return 5 if - * called under rcu_read_lock. + * Return: The index of the gap if found, otherwise an index outside the + * range specified (in which case 'index - return >= max_scan' will be true). + * In the rare case of wrap-around, ULONG_MAX will be returned. */ -pgoff_t page_cache_prev_hole(struct address_space *mapping, +pgoff_t page_cache_prev_miss(struct address_space *mapping, pgoff_t index, unsigned long max_scan) { - unsigned long i; + XA_STATE(xas, &mapping->i_pages, index); - for (i = 0; i < max_scan; i++) { - struct page *page; - - page = radix_tree_lookup(&mapping->i_pages, index); - if (!page || radix_tree_exceptional_entry(page)) + while (max_scan--) { + void *entry = xas_prev(&xas); + if (!entry || xa_is_value(entry)) break; - index--; - if (index == ULONG_MAX) + if (xas.xa_index == ULONG_MAX) break; } - return index; + return xas.xa_index; } -EXPORT_SYMBOL(page_cache_prev_hole); +EXPORT_SYMBOL(page_cache_prev_miss); /** * find_get_entry - find and get a page cache entry @@ -1437,47 +1406,40 @@ EXPORT_SYMBOL(page_cache_prev_hole); */ struct page *find_get_entry(struct address_space *mapping, pgoff_t offset) { - void **pagep; + XA_STATE(xas, &mapping->i_pages, offset); struct page *head, *page; rcu_read_lock(); repeat: - page = NULL; - pagep = radix_tree_lookup_slot(&mapping->i_pages, offset); - if (pagep) { - page = radix_tree_deref_slot(pagep); - if (unlikely(!page)) - goto out; - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) - goto repeat; - /* - * A shadow entry of a recently evicted page, - * or a swap entry from shmem/tmpfs. Return - * it without attempting to raise page count. - */ - goto out; - } + xas_reset(&xas); + page = xas_load(&xas); + if (xas_retry(&xas, page)) + goto repeat; + /* + * A shadow entry of a recently evicted page, or a swap entry from + * shmem/tmpfs. Return it without attempting to raise page count. + */ + if (!page || xa_is_value(page)) + goto out; - head = compound_head(page); - if (!page_cache_get_speculative(head)) - goto repeat; + head = compound_head(page); + if (!page_cache_get_speculative(head)) + goto repeat; - /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); + goto repeat; + } - /* - * Has the page moved? - * This is part of the lockless pagecache protocol. See - * include/linux/pagemap.h for details. - */ - if (unlikely(page != *pagep)) { - put_page(head); - goto repeat; - } + /* + * Has the page moved? + * This is part of the lockless pagecache protocol. See + * include/linux/pagemap.h for details. + */ + if (unlikely(page != xas_reload(&xas))) { + put_page(head); + goto repeat; } out: rcu_read_unlock(); @@ -1508,7 +1470,7 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset) repeat: page = find_get_entry(mapping, offset); - if (page && !radix_tree_exception(page)) { + if (page && !xa_is_value(page)) { lock_page(page); /* Has the page been truncated? */ if (unlikely(page_mapping(page) != mapping)) { @@ -1554,7 +1516,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset, repeat: page = find_get_entry(mapping, offset); - if (radix_tree_exceptional_entry(page)) + if (xa_is_value(page)) page = NULL; if (!page) goto no_page; @@ -1640,53 +1602,48 @@ unsigned find_get_entries(struct address_space *mapping, pgoff_t start, unsigned int nr_entries, struct page **entries, pgoff_t *indices) { - void **slot; + XA_STATE(xas, &mapping->i_pages, start); + struct page *page; unsigned int ret = 0; - struct radix_tree_iter iter; if (!nr_entries) return 0; rcu_read_lock(); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { - struct page *head, *page; -repeat: - page = radix_tree_deref_slot(slot); - if (unlikely(!page)) + xas_for_each(&xas, page, ULONG_MAX) { + struct page *head; + if (xas_retry(&xas, page)) continue; - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - /* - * A shadow entry of a recently evicted page, a swap - * entry from shmem/tmpfs or a DAX entry. Return it - * without attempting to raise page count. - */ + /* + * A shadow entry of a recently evicted page, a swap + * entry from shmem/tmpfs or a DAX entry. Return it + * without attempting to raise page count. + */ + if (xa_is_value(page)) goto export; - } head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto retry; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto put_page; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; + export: - indices[ret] = iter.index; + indices[ret] = xas.xa_index; entries[ret] = page; if (++ret == nr_entries) break; + continue; +put_page: + put_page(head); +retry: + xas_reset(&xas); } rcu_read_unlock(); return ret; @@ -1717,64 +1674,50 @@ unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start, pgoff_t end, unsigned int nr_pages, struct page **pages) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, *start); + struct page *page; unsigned ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, *start) { - struct page *head, *page; - - if (iter.index > end) - break; -repeat: - page = radix_tree_deref_slot(slot); - if (unlikely(!page)) + xas_for_each(&xas, page, end) { + struct page *head; + if (xas_retry(&xas, page)) continue; - - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - /* - * A shadow entry of a recently evicted page, - * or a swap entry from shmem/tmpfs. Skip - * over it. - */ + /* Skip over shadow, swap and DAX entries */ + if (xa_is_value(page)) continue; - } head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto retry; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto put_page; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; pages[ret] = page; if (++ret == nr_pages) { - *start = pages[ret - 1]->index + 1; + *start = page->index + 1; goto out; } + continue; +put_page: + put_page(head); +retry: + xas_reset(&xas); } /* * We come here when there is no page beyond @end. We take care to not * overflow the index @start as it confuses some of the callers. This - * breaks the iteration when there is page at index -1 but that is + * breaks the iteration when there is a page at index -1 but that is * already broken anyway. */ if (end == (pgoff_t)-1) @@ -1802,57 +1745,43 @@ out: unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, unsigned int nr_pages, struct page **pages) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, index); + struct page *page; unsigned int ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, index) { - struct page *head, *page; -repeat: - page = radix_tree_deref_slot(slot); - /* The hole, there no reason to continue */ - if (unlikely(!page)) + for (page = xas_load(&xas); page; page = xas_next(&xas)) { + struct page *head; + if (xas_retry(&xas, page)) + continue; + /* + * If the entry has been swapped out, we can stop looking. + * No current caller is looking for DAX entries. + */ + if (xa_is_value(page)) break; - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - /* - * A shadow entry of a recently evicted page, - * or a swap entry from shmem/tmpfs. Stop - * looking for contiguous pages. - */ - break; - } - head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto retry; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto put_page; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; /* * must check mapping and index after taking the ref. * otherwise we can get both false positives and false * negatives, which is just confusing to the caller. */ - if (page->mapping == NULL || page_to_pgoff(page) != iter.index) { + if (!page->mapping || page_to_pgoff(page) != xas.xa_index) { put_page(page); break; } @@ -1860,6 +1789,11 @@ repeat: pages[ret] = page; if (++ret == nr_pages) break; + continue; +put_page: + put_page(head); +retry: + xas_reset(&xas); } rcu_read_unlock(); return ret; @@ -1879,74 +1813,58 @@ EXPORT_SYMBOL(find_get_pages_contig); * @tag. We update @index to index the next page for the traversal. */ unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index, - pgoff_t end, int tag, unsigned int nr_pages, + pgoff_t end, xa_mark_t tag, unsigned int nr_pages, struct page **pages) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, *index); + struct page *page; unsigned ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, *index, tag) { - struct page *head, *page; - - if (iter.index > end) - break; -repeat: - page = radix_tree_deref_slot(slot); - if (unlikely(!page)) + xas_for_each_marked(&xas, page, end, tag) { + struct page *head; + if (xas_retry(&xas, page)) continue; - - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - /* - * A shadow entry of a recently evicted page. - * - * Those entries should never be tagged, but - * this tree walk is lockless and the tags are - * looked up in bulk, one radix tree node at a - * time, so there is a sizable window for page - * reclaim to evict a page we saw tagged. - * - * Skip over it. - */ + /* + * Shadow entries should never be tagged, but this iteration + * is lockless so there is a window for page reclaim to evict + * a page we saw tagged. Skip over it. + */ + if (xa_is_value(page)) continue; - } head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto retry; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto put_page; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; pages[ret] = page; if (++ret == nr_pages) { - *index = pages[ret - 1]->index + 1; + *index = page->index + 1; goto out; } + continue; +put_page: + put_page(head); +retry: + xas_reset(&xas); } /* - * We come here when we got at @end. We take care to not overflow the + * We come here when we got to @end. We take care to not overflow the * index @index as it confuses some of the callers. This breaks the - * iteration when there is page at index -1 but that is already broken - * anyway. + * iteration when there is a page at index -1 but that is already + * broken anyway. */ if (end == (pgoff_t)-1) *index = (pgoff_t)-1; @@ -1972,57 +1890,51 @@ EXPORT_SYMBOL(find_get_pages_range_tag); * @tag. */ unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start, - int tag, unsigned int nr_entries, + xa_mark_t tag, unsigned int nr_entries, struct page **entries, pgoff_t *indices) { - void **slot; + XA_STATE(xas, &mapping->i_pages, start); + struct page *page; unsigned int ret = 0; - struct radix_tree_iter iter; if (!nr_entries) return 0; rcu_read_lock(); - radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, start, tag) { - struct page *head, *page; -repeat: - page = radix_tree_deref_slot(slot); - if (unlikely(!page)) + xas_for_each_marked(&xas, page, ULONG_MAX, tag) { + struct page *head; + if (xas_retry(&xas, page)) continue; - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - - /* - * A shadow entry of a recently evicted page, a swap - * entry from shmem/tmpfs or a DAX entry. Return it - * without attempting to raise page count. - */ + /* + * A shadow entry of a recently evicted page, a swap + * entry from shmem/tmpfs or a DAX entry. Return it + * without attempting to raise page count. + */ + if (xa_is_value(page)) goto export; - } head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto retry; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto put_page; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; + export: - indices[ret] = iter.index; + indices[ret] = xas.xa_index; entries[ret] = page; if (++ret == nr_entries) break; + continue; +put_page: + put_page(head); +retry: + xas_reset(&xas); } rcu_read_unlock(); return ret; @@ -2626,45 +2538,31 @@ EXPORT_SYMBOL(filemap_fault); void filemap_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff) { - struct radix_tree_iter iter; - void **slot; struct file *file = vmf->vma->vm_file; struct address_space *mapping = file->f_mapping; pgoff_t last_pgoff = start_pgoff; unsigned long max_idx; + XA_STATE(xas, &mapping->i_pages, start_pgoff); struct page *head, *page; rcu_read_lock(); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start_pgoff) { - if (iter.index > end_pgoff) - break; -repeat: - page = radix_tree_deref_slot(slot); - if (unlikely(!page)) + xas_for_each(&xas, page, end_pgoff) { + if (xas_retry(&xas, page)) + continue; + if (xa_is_value(page)) goto next; - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - goto next; - } head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto next; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto skip; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto skip; if (!PageUptodate(page) || PageReadahead(page) || @@ -2683,10 +2581,10 @@ repeat: if (file->f_ra.mmap_miss > 0) file->f_ra.mmap_miss--; - vmf->address += (iter.index - last_pgoff) << PAGE_SHIFT; + vmf->address += (xas.xa_index - last_pgoff) << PAGE_SHIFT; if (vmf->pte) - vmf->pte += iter.index - last_pgoff; - last_pgoff = iter.index; + vmf->pte += xas.xa_index - last_pgoff; + last_pgoff = xas.xa_index; if (alloc_set_pte(vmf, NULL, page)) goto unlock; unlock_page(page); @@ -2699,8 +2597,6 @@ next: /* Huge page is mapped? No need to proceed. */ if (pmd_trans_huge(*vmf->pmd)) break; - if (iter.index == end_pgoff) - break; } rcu_read_unlock(); } @@ -2810,7 +2706,7 @@ repeat: put_page(page); if (err == -EEXIST) goto repeat; - /* Presumably ENOMEM for radix tree node */ + /* Presumably ENOMEM for xarray node */ return ERR_PTR(err); } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 25ef59b7ee34..4e4ef8fa479d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2450,13 +2450,13 @@ static void __split_huge_page(struct page *page, struct list_head *list, ClearPageCompound(head); /* See comment in __split_huge_page_tail() */ if (PageAnon(head)) { - /* Additional pin to radix tree of swap cache */ + /* Additional pin to swap cache */ if (PageSwapCache(head)) page_ref_add(head, 2); else page_ref_inc(head); } else { - /* Additional pin to radix tree */ + /* Additional pin to page cache */ page_ref_add(head, 2); xa_unlock(&head->mapping->i_pages); } @@ -2568,7 +2568,7 @@ bool can_split_huge_page(struct page *page, int *pextra_pins) { int extra_pins; - /* Additional pins from radix tree */ + /* Additional pins from page cache */ if (PageAnon(page)) extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0; else @@ -2664,17 +2664,14 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) spin_lock_irqsave(zone_lru_lock(page_zone(head)), flags); if (mapping) { - void **pslot; + XA_STATE(xas, &mapping->i_pages, page_index(head)); - xa_lock(&mapping->i_pages); - pslot = radix_tree_lookup_slot(&mapping->i_pages, - page_index(head)); /* - * Check if the head page is present in radix tree. + * Check if the head page is present in page cache. * We assume all tail are present too, if head is there. */ - if (radix_tree_deref_slot_protected(pslot, - &mapping->i_pages.xa_lock) != head) + xa_lock(&mapping->i_pages); + if (xas_load(&xas) != head) goto fail; } diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a31d740e6cd1..c13625c1ad5e 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1288,17 +1288,17 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) * * Basic scheme is simple, details are more complex: * - allocate and freeze a new huge page; - * - scan over radix tree replacing old pages the new one + * - scan page cache replacing old pages with the new one * + swap in pages if necessary; * + fill in gaps; - * + keep old pages around in case if rollback is required; - * - if replacing succeed: + * + keep old pages around in case rollback is required; + * - if replacing succeeds: * + copy data over; * + free old pages; * + unfreeze huge page; * - if replacing failed; * + put all pages back and unfreeze them; - * + restore gaps in the radix-tree; + * + restore gaps in the page cache; * + free huge page; */ static void collapse_shmem(struct mm_struct *mm, @@ -1306,12 +1306,11 @@ static void collapse_shmem(struct mm_struct *mm, struct page **hpage, int node) { gfp_t gfp; - struct page *page, *new_page, *tmp; + struct page *new_page; struct mem_cgroup *memcg; pgoff_t index, end = start + HPAGE_PMD_NR; LIST_HEAD(pagelist); - struct radix_tree_iter iter; - void **slot; + XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER); int nr_none = 0, result = SCAN_SUCCEED; VM_BUG_ON(start & (HPAGE_PMD_NR - 1)); @@ -1336,48 +1335,49 @@ static void collapse_shmem(struct mm_struct *mm, __SetPageLocked(new_page); BUG_ON(!page_ref_freeze(new_page, 1)); - /* - * At this point the new_page is 'frozen' (page_count() is zero), locked - * and not up-to-date. It's safe to insert it into radix tree, because - * nobody would be able to map it or use it in other way until we - * unfreeze it. + * At this point the new_page is 'frozen' (page_count() is zero), + * locked and not up-to-date. It's safe to insert it into the page + * cache, because nobody would be able to map it or use it in other + * way until we unfreeze it. */ - index = start; - xa_lock_irq(&mapping->i_pages); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { - int n = min(iter.index, end) - index; - - /* - * Handle holes in the radix tree: charge it from shmem and - * insert relevant subpage of new_page into the radix-tree. - */ - if (n && !shmem_charge(mapping->host, n)) { - result = SCAN_FAIL; + /* This will be less messy when we use multi-index entries */ + do { + xas_lock_irq(&xas); + xas_create_range(&xas); + if (!xas_error(&xas)) break; - } - nr_none += n; - for (; index < min(iter.index, end); index++) { - radix_tree_insert(&mapping->i_pages, index, - new_page + (index % HPAGE_PMD_NR)); + xas_unlock_irq(&xas); + if (!xas_nomem(&xas, GFP_KERNEL)) + goto out; + } while (1); + + xas_set(&xas, start); + for (index = start; index < end; index++) { + struct page *page = xas_next(&xas); + + VM_BUG_ON(index != xas.xa_index); + if (!page) { + if (!shmem_charge(mapping->host, 1)) { + result = SCAN_FAIL; + break; + } + xas_store(&xas, new_page + (index % HPAGE_PMD_NR)); + nr_none++; + continue; } - /* We are done. */ - if (index >= end) - break; - - page = radix_tree_deref_slot_protected(slot, - &mapping->i_pages.xa_lock); - if (radix_tree_exceptional_entry(page) || !PageUptodate(page)) { - xa_unlock_irq(&mapping->i_pages); + if (xa_is_value(page) || !PageUptodate(page)) { + xas_unlock_irq(&xas); /* swap in or instantiate fallocated page */ if (shmem_getpage(mapping->host, index, &page, SGP_NOHUGE)) { result = SCAN_FAIL; - goto tree_unlocked; + goto xa_unlocked; } - xa_lock_irq(&mapping->i_pages); + xas_lock_irq(&xas); + xas_set(&xas, index); } else if (trylock_page(page)) { get_page(page); } else { @@ -1397,7 +1397,7 @@ static void collapse_shmem(struct mm_struct *mm, result = SCAN_TRUNCATED; goto out_unlock; } - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); if (isolate_lru_page(page)) { result = SCAN_DEL_PAGE_LRU; @@ -1407,17 +1407,16 @@ static void collapse_shmem(struct mm_struct *mm, if (page_mapped(page)) unmap_mapping_pages(mapping, index, 1, false); - xa_lock_irq(&mapping->i_pages); + xas_lock_irq(&xas); + xas_set(&xas, index); - slot = radix_tree_lookup_slot(&mapping->i_pages, index); - VM_BUG_ON_PAGE(page != radix_tree_deref_slot_protected(slot, - &mapping->i_pages.xa_lock), page); + VM_BUG_ON_PAGE(page != xas_load(&xas), page); VM_BUG_ON_PAGE(page_mapped(page), page); /* * The page is expected to have page_count() == 3: * - we hold a pin on it; - * - one reference from radix tree; + * - one reference from page cache; * - one from isolate_lru_page; */ if (!page_ref_freeze(page, 3)) { @@ -1432,56 +1431,30 @@ static void collapse_shmem(struct mm_struct *mm, list_add_tail(&page->lru, &pagelist); /* Finally, replace with the new page. */ - radix_tree_replace_slot(&mapping->i_pages, slot, - new_page + (index % HPAGE_PMD_NR)); - - slot = radix_tree_iter_resume(slot, &iter); - index++; + xas_store(&xas, new_page + (index % HPAGE_PMD_NR)); continue; out_lru: - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); putback_lru_page(page); out_isolate_failed: unlock_page(page); put_page(page); - goto tree_unlocked; + goto xa_unlocked; out_unlock: unlock_page(page); put_page(page); break; } + xas_unlock_irq(&xas); - /* - * Handle hole in radix tree at the end of the range. - * This code only triggers if there's nothing in radix tree - * beyond 'end'. - */ - if (result == SCAN_SUCCEED && index < end) { - int n = end - index; - - if (!shmem_charge(mapping->host, n)) { - result = SCAN_FAIL; - goto tree_locked; - } - - for (; index < end; index++) { - radix_tree_insert(&mapping->i_pages, index, - new_page + (index % HPAGE_PMD_NR)); - } - nr_none += n; - } - -tree_locked: - xa_unlock_irq(&mapping->i_pages); -tree_unlocked: - +xa_unlocked: if (result == SCAN_SUCCEED) { - unsigned long flags; + struct page *page, *tmp; struct zone *zone = page_zone(new_page); /* - * Replacing old pages with new one has succeed, now we need to - * copy the content and free old pages. + * Replacing old pages with new one has succeeded, now we + * need to copy the content and free the old pages. */ list_for_each_entry_safe(page, tmp, &pagelist, lru) { copy_highpage(new_page + (page->index % HPAGE_PMD_NR), @@ -1495,16 +1468,16 @@ tree_unlocked: put_page(page); } - local_irq_save(flags); + local_irq_disable(); __inc_node_page_state(new_page, NR_SHMEM_THPS); if (nr_none) { __mod_node_page_state(zone->zone_pgdat, NR_FILE_PAGES, nr_none); __mod_node_page_state(zone->zone_pgdat, NR_SHMEM, nr_none); } - local_irq_restore(flags); + local_irq_enable(); /* - * Remove pte page tables, so we can re-faulti + * Remove pte page tables, so we can re-fault * the page as huge. */ retract_page_tables(mapping, start); @@ -1521,37 +1494,37 @@ tree_unlocked: khugepaged_pages_collapsed++; } else { - /* Something went wrong: rollback changes to the radix-tree */ + struct page *page; + /* Something went wrong: roll back page cache changes */ shmem_uncharge(mapping->host, nr_none); - xa_lock_irq(&mapping->i_pages); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { - if (iter.index >= end) - break; + xas_lock_irq(&xas); + xas_set(&xas, start); + xas_for_each(&xas, page, end - 1) { page = list_first_entry_or_null(&pagelist, struct page, lru); - if (!page || iter.index < page->index) { + if (!page || xas.xa_index < page->index) { if (!nr_none) break; nr_none--; /* Put holes back where they were */ - radix_tree_delete(&mapping->i_pages, iter.index); + xas_store(&xas, NULL); continue; } - VM_BUG_ON_PAGE(page->index != iter.index, page); + VM_BUG_ON_PAGE(page->index != xas.xa_index, page); /* Unfreeze the page. */ list_del(&page->lru); page_ref_unfreeze(page, 2); - radix_tree_replace_slot(&mapping->i_pages, slot, page); - slot = radix_tree_iter_resume(slot, &iter); - xa_unlock_irq(&mapping->i_pages); + xas_store(&xas, page); + xas_pause(&xas); + xas_unlock_irq(&xas); putback_lru_page(page); unlock_page(page); - xa_lock_irq(&mapping->i_pages); + xas_lock_irq(&xas); } VM_BUG_ON(nr_none); - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); /* Unfreeze new_page, caller would take care about freeing it */ page_ref_unfreeze(new_page, 1); @@ -1569,8 +1542,7 @@ static void khugepaged_scan_shmem(struct mm_struct *mm, pgoff_t start, struct page **hpage) { struct page *page = NULL; - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, start); int present, swap; int node = NUMA_NO_NODE; int result = SCAN_SUCCEED; @@ -1579,17 +1551,11 @@ static void khugepaged_scan_shmem(struct mm_struct *mm, swap = 0; memset(khugepaged_node_load, 0, sizeof(khugepaged_node_load)); rcu_read_lock(); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { - if (iter.index >= start + HPAGE_PMD_NR) - break; - - page = radix_tree_deref_slot(slot); - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); + xas_for_each(&xas, page, start + HPAGE_PMD_NR - 1) { + if (xas_retry(&xas, page)) continue; - } - if (radix_tree_exception(page)) { + if (xa_is_value(page)) { if (++swap > khugepaged_max_ptes_swap) { result = SCAN_EXCEED_SWAP_PTE; break; @@ -1628,7 +1594,7 @@ static void khugepaged_scan_shmem(struct mm_struct *mm, present++; if (need_resched()) { - slot = radix_tree_iter_resume(slot, &iter); + xas_pause(&xas); cond_resched_rcu(); } } diff --git a/mm/madvise.c b/mm/madvise.c index 71d21df2a3f3..6cb1ca93e290 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -251,7 +251,7 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma, index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; page = find_get_entry(mapping, index); - if (!radix_tree_exceptional_entry(page)) { + if (!xa_is_value(page)) { if (page) put_page(page); continue; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 10a9b554d69f..54920cbc46bf 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4728,7 +4728,7 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma, /* shmem/tmpfs may report page out on swap: account for that too. */ if (shmem_mapping(mapping)) { page = find_get_entry(mapping, pgoff); - if (radix_tree_exceptional_entry(page)) { + if (xa_is_value(page)) { swp_entry_t swp = radix_to_swp_entry(page); if (do_memsw_account()) *entry = swp; diff --git a/mm/memfd.c b/mm/memfd.c index 2bb5e257080e..97264c79d2cd 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -21,44 +21,36 @@ #include /* - * We need a tag: a new tag would expand every radix_tree_node by 8 bytes, + * We need a tag: a new tag would expand every xa_node by 8 bytes, * so reuse a tag which we firmly believe is never set or cleared on tmpfs * or hugetlbfs because they are memory only filesystems. */ #define MEMFD_TAG_PINNED PAGECACHE_TAG_TOWRITE #define LAST_SCAN 4 /* about 150ms max */ -static void memfd_tag_pins(struct address_space *mapping) +static void memfd_tag_pins(struct xa_state *xas) { - struct radix_tree_iter iter; - void __rcu **slot; - pgoff_t start; struct page *page; + unsigned int tagged = 0; lru_add_drain(); - start = 0; - rcu_read_lock(); - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { - page = radix_tree_deref_slot(slot); - if (!page || radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - } else if (page_count(page) - page_mapcount(page) > 1) { - xa_lock_irq(&mapping->i_pages); - radix_tree_tag_set(&mapping->i_pages, iter.index, - MEMFD_TAG_PINNED); - xa_unlock_irq(&mapping->i_pages); - } + xas_lock_irq(xas); + xas_for_each(xas, page, ULONG_MAX) { + if (xa_is_value(page)) + continue; + if (page_count(page) - page_mapcount(page) > 1) + xas_set_mark(xas, MEMFD_TAG_PINNED); - if (need_resched()) { - slot = radix_tree_iter_resume(slot, &iter); - cond_resched_rcu(); - } + if (++tagged % XA_CHECK_SCHED) + continue; + + xas_pause(xas); + xas_unlock_irq(xas); + cond_resched(); + xas_lock_irq(xas); } - rcu_read_unlock(); + xas_unlock_irq(xas); } /* @@ -72,17 +64,17 @@ static void memfd_tag_pins(struct address_space *mapping) */ static int memfd_wait_for_pins(struct address_space *mapping) { - struct radix_tree_iter iter; - void __rcu **slot; - pgoff_t start; + XA_STATE(xas, &mapping->i_pages, 0); struct page *page; int error, scan; - memfd_tag_pins(mapping); + memfd_tag_pins(&xas); error = 0; for (scan = 0; scan <= LAST_SCAN; scan++) { - if (!radix_tree_tagged(&mapping->i_pages, MEMFD_TAG_PINNED)) + unsigned int tagged = 0; + + if (!xas_marked(&xas, MEMFD_TAG_PINNED)) break; if (!scan) @@ -90,45 +82,34 @@ static int memfd_wait_for_pins(struct address_space *mapping) else if (schedule_timeout_killable((HZ << scan) / 200)) scan = LAST_SCAN; - start = 0; - rcu_read_lock(); - radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, - start, MEMFD_TAG_PINNED) { - - page = radix_tree_deref_slot(slot); - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - - page = NULL; - } - - if (page && - page_count(page) - page_mapcount(page) != 1) { - if (scan < LAST_SCAN) - goto continue_resched; - + xas_set(&xas, 0); + xas_lock_irq(&xas); + xas_for_each_marked(&xas, page, ULONG_MAX, MEMFD_TAG_PINNED) { + bool clear = true; + if (xa_is_value(page)) + continue; + if (page_count(page) - page_mapcount(page) != 1) { /* * On the last scan, we clean up all those tags * we inserted; but make a note that we still * found pages pinned. */ - error = -EBUSY; + if (scan == LAST_SCAN) + error = -EBUSY; + else + clear = false; } + if (clear) + xas_clear_mark(&xas, MEMFD_TAG_PINNED); + if (++tagged % XA_CHECK_SCHED) + continue; - xa_lock_irq(&mapping->i_pages); - radix_tree_tag_clear(&mapping->i_pages, - iter.index, MEMFD_TAG_PINNED); - xa_unlock_irq(&mapping->i_pages); -continue_resched: - if (need_resched()) { - slot = radix_tree_iter_resume(slot, &iter); - cond_resched_rcu(); - } + xas_pause(&xas); + xas_unlock_irq(&xas); + cond_resched(); + xas_lock_irq(&xas); } - rcu_read_unlock(); + xas_unlock_irq(&xas); } return error; diff --git a/mm/migrate.c b/mm/migrate.c index b6700f2962f3..f7e4bfdc13b7 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -326,7 +326,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, page = migration_entry_to_page(entry); /* - * Once radix-tree replacement of page migration started, page_count + * Once page cache replacement of page migration started, page_count * *must* be zero. And, we don't want to call wait_on_page_locked() * against a page without get_page(). * So, we use get_page_unless_zero(), here. Even failed, page fault @@ -441,10 +441,10 @@ int migrate_page_move_mapping(struct address_space *mapping, struct buffer_head *head, enum migrate_mode mode, int extra_count) { + XA_STATE(xas, &mapping->i_pages, page_index(page)); struct zone *oldzone, *newzone; int dirty; int expected_count = 1 + extra_count; - void **pslot; /* * Device public or private pages have an extra refcount as they are @@ -470,21 +470,16 @@ int migrate_page_move_mapping(struct address_space *mapping, oldzone = page_zone(page); newzone = page_zone(newpage); - xa_lock_irq(&mapping->i_pages); - - pslot = radix_tree_lookup_slot(&mapping->i_pages, - page_index(page)); + xas_lock_irq(&xas); expected_count += hpage_nr_pages(page) + page_has_private(page); - if (page_count(page) != expected_count || - radix_tree_deref_slot_protected(pslot, - &mapping->i_pages.xa_lock) != page) { - xa_unlock_irq(&mapping->i_pages); + if (page_count(page) != expected_count || xas_load(&xas) != page) { + xas_unlock_irq(&xas); return -EAGAIN; } if (!page_ref_freeze(page, expected_count)) { - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -498,7 +493,7 @@ int migrate_page_move_mapping(struct address_space *mapping, if (mode == MIGRATE_ASYNC && head && !buffer_migrate_lock_buffers(head, mode)) { page_ref_unfreeze(page, expected_count); - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -526,16 +521,13 @@ int migrate_page_move_mapping(struct address_space *mapping, SetPageDirty(newpage); } - radix_tree_replace_slot(&mapping->i_pages, pslot, newpage); + xas_store(&xas, newpage); if (PageTransHuge(page)) { int i; - int index = page_index(page); for (i = 1; i < HPAGE_PMD_NR; i++) { - pslot = radix_tree_lookup_slot(&mapping->i_pages, - index + i); - radix_tree_replace_slot(&mapping->i_pages, pslot, - newpage + i); + xas_next(&xas); + xas_store(&xas, newpage + i); } } @@ -546,7 +538,7 @@ int migrate_page_move_mapping(struct address_space *mapping, */ page_ref_unfreeze(page, expected_count - hpage_nr_pages(page)); - xa_unlock(&mapping->i_pages); + xas_unlock(&xas); /* Leave irq disabled to prevent preemption while updating stats */ /* @@ -586,22 +578,18 @@ EXPORT_SYMBOL(migrate_page_move_mapping); int migrate_huge_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page) { + XA_STATE(xas, &mapping->i_pages, page_index(page)); int expected_count; - void **pslot; - - xa_lock_irq(&mapping->i_pages); - - pslot = radix_tree_lookup_slot(&mapping->i_pages, page_index(page)); + xas_lock_irq(&xas); expected_count = 2 + page_has_private(page); - if (page_count(page) != expected_count || - radix_tree_deref_slot_protected(pslot, &mapping->i_pages.xa_lock) != page) { - xa_unlock_irq(&mapping->i_pages); + if (page_count(page) != expected_count || xas_load(&xas) != page) { + xas_unlock_irq(&xas); return -EAGAIN; } if (!page_ref_freeze(page, expected_count)) { - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); return -EAGAIN; } @@ -610,11 +598,11 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, get_page(newpage); - radix_tree_replace_slot(&mapping->i_pages, pslot, newpage); + xas_store(&xas, newpage); page_ref_unfreeze(page, expected_count - 1); - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); return MIGRATEPAGE_SUCCESS; } diff --git a/mm/mincore.c b/mm/mincore.c index fc37afe226e6..4985965aa20a 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -66,7 +66,7 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff) * shmem/tmpfs may return swap: account for swapcache * page too. */ - if (radix_tree_exceptional_entry(page)) { + if (xa_is_value(page)) { swp_entry_t swp = radix_to_swp_entry(page); page = find_get_page(swap_address_space(swp), swp_offset(swp)); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 439a304a6c92..3f690bae6b78 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2097,34 +2097,25 @@ void __init page_writeback_init(void) * dirty pages in the file (thus it is important for this function to be quick * so that it can tag pages faster than a dirtying process can create them). */ -/* - * We tag pages in batches of WRITEBACK_TAG_BATCH to reduce the i_pages lock - * latency. - */ void tag_pages_for_writeback(struct address_space *mapping, pgoff_t start, pgoff_t end) { -#define WRITEBACK_TAG_BATCH 4096 - unsigned long tagged = 0; - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, start); + unsigned int tagged = 0; + void *page; - xa_lock_irq(&mapping->i_pages); - radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, start, - PAGECACHE_TAG_DIRTY) { - if (iter.index > end) - break; - radix_tree_iter_tag_set(&mapping->i_pages, &iter, - PAGECACHE_TAG_TOWRITE); - tagged++; - if ((tagged % WRITEBACK_TAG_BATCH) != 0) + xas_lock_irq(&xas); + xas_for_each_marked(&xas, page, end, PAGECACHE_TAG_DIRTY) { + xas_set_mark(&xas, PAGECACHE_TAG_TOWRITE); + if (++tagged % XA_CHECK_SCHED) continue; - slot = radix_tree_iter_resume(slot, &iter); - xa_unlock_irq(&mapping->i_pages); + + xas_pause(&xas); + xas_unlock_irq(&xas); cond_resched(); - xa_lock_irq(&mapping->i_pages); + xas_lock_irq(&xas); } - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); } EXPORT_SYMBOL(tag_pages_for_writeback); @@ -2170,7 +2161,7 @@ int write_cache_pages(struct address_space *mapping, pgoff_t end; /* Inclusive */ pgoff_t done_index; int range_whole = 0; - int tag; + xa_mark_t tag; pagevec_init(&pvec); if (wbc->range_cyclic) { @@ -2442,7 +2433,7 @@ void account_page_cleaned(struct page *page, struct address_space *mapping, /* * For address_spaces which do not use buffers. Just tag the page as dirty in - * its radix tree. + * the xarray. * * This is also used when a single buffer is being dirtied: we want to set the * page dirty in that case, but not all the buffers. This is a "bottom-up" @@ -2468,7 +2459,7 @@ int __set_page_dirty_nobuffers(struct page *page) BUG_ON(page_mapping(page) != mapping); WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page)); account_page_dirtied(page, mapping); - radix_tree_tag_set(&mapping->i_pages, page_index(page), + __xa_set_mark(&mapping->i_pages, page_index(page), PAGECACHE_TAG_DIRTY); xa_unlock_irqrestore(&mapping->i_pages, flags); unlock_page_memcg(page); @@ -2631,13 +2622,13 @@ EXPORT_SYMBOL(__cancel_dirty_page); * Returns true if the page was previously dirty. * * This is for preparing to put the page under writeout. We leave the page - * tagged as dirty in the radix tree so that a concurrent write-for-sync + * tagged as dirty in the xarray so that a concurrent write-for-sync * can discover it via a PAGECACHE_TAG_DIRTY walk. The ->writepage * implementation will run either set_page_writeback() or set_page_dirty(), - * at which stage we bring the page's dirty flag and radix-tree dirty tag + * at which stage we bring the page's dirty flag and xarray dirty tag * back into sync. * - * This incoherency between the page's dirty flag and radix-tree tag is + * This incoherency between the page's dirty flag and xarray tag is * unfortunate, but it only exists while the page is locked. */ int clear_page_dirty_for_io(struct page *page) @@ -2718,7 +2709,7 @@ int test_clear_page_writeback(struct page *page) xa_lock_irqsave(&mapping->i_pages, flags); ret = TestClearPageWriteback(page); if (ret) { - radix_tree_tag_clear(&mapping->i_pages, page_index(page), + __xa_clear_mark(&mapping->i_pages, page_index(page), PAGECACHE_TAG_WRITEBACK); if (bdi_cap_account_writeback(bdi)) { struct bdi_writeback *wb = inode_to_wb(inode); @@ -2758,11 +2749,13 @@ int __test_set_page_writeback(struct page *page, bool keep_write) lock_page_memcg(page); if (mapping && mapping_use_writeback_tags(mapping)) { + XA_STATE(xas, &mapping->i_pages, page_index(page)); struct inode *inode = mapping->host; struct backing_dev_info *bdi = inode_to_bdi(inode); unsigned long flags; - xa_lock_irqsave(&mapping->i_pages, flags); + xas_lock_irqsave(&xas, flags); + xas_load(&xas); ret = TestSetPageWriteback(page); if (!ret) { bool on_wblist; @@ -2770,8 +2763,7 @@ int __test_set_page_writeback(struct page *page, bool keep_write) on_wblist = mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); - radix_tree_tag_set(&mapping->i_pages, page_index(page), - PAGECACHE_TAG_WRITEBACK); + xas_set_mark(&xas, PAGECACHE_TAG_WRITEBACK); if (bdi_cap_account_writeback(bdi)) inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK); @@ -2784,12 +2776,10 @@ int __test_set_page_writeback(struct page *page, bool keep_write) sb_mark_inode_writeback(mapping->host); } if (!PageDirty(page)) - radix_tree_tag_clear(&mapping->i_pages, page_index(page), - PAGECACHE_TAG_DIRTY); + xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY); if (!keep_write) - radix_tree_tag_clear(&mapping->i_pages, page_index(page), - PAGECACHE_TAG_TOWRITE); - xa_unlock_irqrestore(&mapping->i_pages, flags); + xas_clear_mark(&xas, PAGECACHE_TAG_TOWRITE); + xas_unlock_irqrestore(&xas, flags); } else { ret = TestSetPageWriteback(page); } @@ -2803,16 +2793,6 @@ int __test_set_page_writeback(struct page *page, bool keep_write) } EXPORT_SYMBOL(__test_set_page_writeback); -/* - * Return true if any of the pages in the mapping are marked with the - * passed tag. - */ -int mapping_tagged(struct address_space *mapping, int tag) -{ - return radix_tree_tagged(&mapping->i_pages, tag); -} -EXPORT_SYMBOL(mapping_tagged); - /** * wait_for_stable_page() - wait for writeback to finish, if necessary. * @page: The page to wait on. diff --git a/mm/readahead.c b/mm/readahead.c index 4e630143a0ba..f3d6f9656a3c 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -176,10 +176,8 @@ unsigned int __do_page_cache_readahead(struct address_space *mapping, if (page_offset > end_index) break; - rcu_read_lock(); - page = radix_tree_lookup(&mapping->i_pages, page_offset); - rcu_read_unlock(); - if (page && !radix_tree_exceptional_entry(page)) { + page = xa_load(&mapping->i_pages, page_offset); + if (page && !xa_is_value(page)) { /* * Page already present? Kick off the current batch of * contiguous pages before continuing with the next @@ -336,7 +334,7 @@ static pgoff_t count_history_pages(struct address_space *mapping, pgoff_t head; rcu_read_lock(); - head = page_cache_prev_hole(mapping, offset - 1, max); + head = page_cache_prev_miss(mapping, offset - 1, max); rcu_read_unlock(); return offset - 1 - head; @@ -425,7 +423,7 @@ ondemand_readahead(struct address_space *mapping, pgoff_t start; rcu_read_lock(); - start = page_cache_next_hole(mapping, offset + 1, max_pages); + start = page_cache_next_miss(mapping, offset + 1, max_pages); rcu_read_unlock(); if (!start || start - offset > max_pages) diff --git a/mm/shmem.c b/mm/shmem.c index 446942677cd4..56bf122e0bb4 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -322,24 +322,20 @@ void shmem_uncharge(struct inode *inode, long pages) } /* - * Replace item expected in radix tree by a new item, while holding tree lock. + * Replace item expected in xarray by a new item, while holding xa_lock. */ -static int shmem_radix_tree_replace(struct address_space *mapping, +static int shmem_replace_entry(struct address_space *mapping, pgoff_t index, void *expected, void *replacement) { - struct radix_tree_node *node; - void __rcu **pslot; + XA_STATE(xas, &mapping->i_pages, index); void *item; VM_BUG_ON(!expected); VM_BUG_ON(!replacement); - item = __radix_tree_lookup(&mapping->i_pages, index, &node, &pslot); - if (!item) - return -ENOENT; + item = xas_load(&xas); if (item != expected) return -ENOENT; - __radix_tree_replace(&mapping->i_pages, node, pslot, - replacement, NULL); + xas_store(&xas, replacement); return 0; } @@ -353,12 +349,7 @@ static int shmem_radix_tree_replace(struct address_space *mapping, static bool shmem_confirm_swap(struct address_space *mapping, pgoff_t index, swp_entry_t swap) { - void *item; - - rcu_read_lock(); - item = radix_tree_lookup(&mapping->i_pages, index); - rcu_read_unlock(); - return item == swp_to_radix_entry(swap); + return xa_load(&mapping->i_pages, index) == swp_to_radix_entry(swap); } /* @@ -586,9 +577,11 @@ static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo) */ static int shmem_add_to_page_cache(struct page *page, struct address_space *mapping, - pgoff_t index, void *expected) + pgoff_t index, void *expected, gfp_t gfp) { - int error, nr = hpage_nr_pages(page); + XA_STATE_ORDER(xas, &mapping->i_pages, index, compound_order(page)); + unsigned long i = 0; + unsigned long nr = 1UL << compound_order(page); VM_BUG_ON_PAGE(PageTail(page), page); VM_BUG_ON_PAGE(index != round_down(index, nr), page); @@ -600,47 +593,39 @@ static int shmem_add_to_page_cache(struct page *page, page->mapping = mapping; page->index = index; - xa_lock_irq(&mapping->i_pages); - if (PageTransHuge(page)) { - void __rcu **results; - pgoff_t idx; - int i; - - error = 0; - if (radix_tree_gang_lookup_slot(&mapping->i_pages, - &results, &idx, index, 1) && - idx < index + HPAGE_PMD_NR) { - error = -EEXIST; + do { + void *entry; + xas_lock_irq(&xas); + entry = xas_find_conflict(&xas); + if (entry != expected) + xas_set_err(&xas, -EEXIST); + xas_create_range(&xas); + if (xas_error(&xas)) + goto unlock; +next: + xas_store(&xas, page + i); + if (++i < nr) { + xas_next(&xas); + goto next; } - - if (!error) { - for (i = 0; i < HPAGE_PMD_NR; i++) { - error = radix_tree_insert(&mapping->i_pages, - index + i, page + i); - VM_BUG_ON(error); - } + if (PageTransHuge(page)) { count_vm_event(THP_FILE_ALLOC); - } - } else if (!expected) { - error = radix_tree_insert(&mapping->i_pages, index, page); - } else { - error = shmem_radix_tree_replace(mapping, index, expected, - page); - } - - if (!error) { - mapping->nrpages += nr; - if (PageTransHuge(page)) __inc_node_page_state(page, NR_SHMEM_THPS); + } + mapping->nrpages += nr; __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr); __mod_node_page_state(page_pgdat(page), NR_SHMEM, nr); - xa_unlock_irq(&mapping->i_pages); - } else { +unlock: + xas_unlock_irq(&xas); + } while (xas_nomem(&xas, gfp)); + + if (xas_error(&xas)) { page->mapping = NULL; - xa_unlock_irq(&mapping->i_pages); page_ref_sub(page, nr); + return xas_error(&xas); } - return error; + + return 0; } /* @@ -654,7 +639,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) VM_BUG_ON_PAGE(PageCompound(page), page); xa_lock_irq(&mapping->i_pages); - error = shmem_radix_tree_replace(mapping, page->index, page, radswap); + error = shmem_replace_entry(mapping, page->index, page, radswap); page->mapping = NULL; mapping->nrpages--; __dec_node_page_state(page, NR_FILE_PAGES); @@ -665,7 +650,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) } /* - * Remove swap entry from radix tree, free the swap and its page cache. + * Remove swap entry from page cache, free the swap and its page cache. */ static int shmem_free_swap(struct address_space *mapping, pgoff_t index, void *radswap) @@ -673,7 +658,7 @@ static int shmem_free_swap(struct address_space *mapping, void *old; xa_lock_irq(&mapping->i_pages); - old = radix_tree_delete_item(&mapping->i_pages, index, radswap); + old = __xa_cmpxchg(&mapping->i_pages, index, radswap, NULL, 0); xa_unlock_irq(&mapping->i_pages); if (old != radswap) return -ENOENT; @@ -691,29 +676,19 @@ static int shmem_free_swap(struct address_space *mapping, unsigned long shmem_partial_swap_usage(struct address_space *mapping, pgoff_t start, pgoff_t end) { - struct radix_tree_iter iter; - void __rcu **slot; + XA_STATE(xas, &mapping->i_pages, start); struct page *page; unsigned long swapped = 0; rcu_read_lock(); - - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { - if (iter.index >= end) - break; - - page = radix_tree_deref_slot(slot); - - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); + xas_for_each(&xas, page, end - 1) { + if (xas_retry(&xas, page)) continue; - } - - if (radix_tree_exceptional_entry(page)) + if (xa_is_value(page)) swapped++; if (need_resched()) { - slot = radix_tree_iter_resume(slot, &iter); + xas_pause(&xas); cond_resched_rcu(); } } @@ -788,7 +763,7 @@ void shmem_unlock_mapping(struct address_space *mapping) } /* - * Remove range of pages and swap entries from radix tree, and free them. + * Remove range of pages and swap entries from page cache, and free them. * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. */ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, @@ -824,7 +799,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, if (index >= end) break; - if (radix_tree_exceptional_entry(page)) { + if (xa_is_value(page)) { if (unfalloc) continue; nr_swaps_freed += !shmem_free_swap(mapping, @@ -921,7 +896,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, if (index >= end) break; - if (radix_tree_exceptional_entry(page)) { + if (xa_is_value(page)) { if (unfalloc) continue; if (shmem_free_swap(mapping, index, page)) { @@ -1110,34 +1085,27 @@ static void shmem_evict_inode(struct inode *inode) clear_inode(inode); } -static unsigned long find_swap_entry(struct radix_tree_root *root, void *item) +static unsigned long find_swap_entry(struct xarray *xa, void *item) { - struct radix_tree_iter iter; - void __rcu **slot; - unsigned long found = -1; + XA_STATE(xas, xa, 0); unsigned int checked = 0; + void *entry; rcu_read_lock(); - radix_tree_for_each_slot(slot, root, &iter, 0) { - void *entry = radix_tree_deref_slot(slot); - - if (radix_tree_deref_retry(entry)) { - slot = radix_tree_iter_retry(&iter); + xas_for_each(&xas, entry, ULONG_MAX) { + if (xas_retry(&xas, entry)) continue; - } - if (entry == item) { - found = iter.index; + if (entry == item) break; - } checked++; - if ((checked % 4096) != 0) + if ((checked % XA_CHECK_SCHED) != 0) continue; - slot = radix_tree_iter_resume(slot, &iter); + xas_pause(&xas); cond_resched_rcu(); } - rcu_read_unlock(); - return found; + + return entry ? xas.xa_index : -1; } /* @@ -1175,10 +1143,10 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, * We needed to drop mutex to make that restrictive page * allocation, but the inode might have been freed while we * dropped it: although a racing shmem_evict_inode() cannot - * complete without emptying the radix_tree, our page lock + * complete without emptying the page cache, our page lock * on this swapcache page is not enough to prevent that - * free_swap_and_cache() of our swap entry will only - * trylock_page(), removing swap from radix_tree whatever. + * trylock_page(), removing swap from page cache whatever. * * We must not proceed to shmem_add_to_page_cache() if the * inode has been freed, but of course we cannot rely on @@ -1200,7 +1168,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, */ if (!error) error = shmem_add_to_page_cache(*pagep, mapping, index, - radswap); + radswap, gfp); if (error != -ENOMEM) { /* * Truncation and eviction use free_swap_and_cache(), which @@ -1244,7 +1212,7 @@ int shmem_unuse(swp_entry_t swap, struct page *page) &memcg, false); if (error) goto out; - /* No radix_tree_preload: swap entry keeps a place for page in tree */ + /* No memory allocation: swap entry occupies the slot for the page */ error = -EAGAIN; mutex_lock(&shmem_swaplist_mutex); @@ -1453,23 +1421,17 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp, struct shmem_inode_info *info, pgoff_t index) { struct vm_area_struct pvma; - struct inode *inode = &info->vfs_inode; - struct address_space *mapping = inode->i_mapping; - pgoff_t idx, hindex; - void __rcu **results; + struct address_space *mapping = info->vfs_inode.i_mapping; + pgoff_t hindex; struct page *page; if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) return NULL; hindex = round_down(index, HPAGE_PMD_NR); - rcu_read_lock(); - if (radix_tree_gang_lookup_slot(&mapping->i_pages, &results, &idx, - hindex, 1) && idx < hindex + HPAGE_PMD_NR) { - rcu_read_unlock(); + if (xa_find(&mapping->i_pages, &hindex, hindex + HPAGE_PMD_NR - 1, + XA_PRESENT)) return NULL; - } - rcu_read_unlock(); shmem_pseudo_vma_init(&pvma, info, hindex); page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN, @@ -1578,8 +1540,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp, * a nice clean interface for us to replace oldpage by newpage there. */ xa_lock_irq(&swap_mapping->i_pages); - error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage, - newpage); + error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage); if (!error) { __inc_node_page_state(newpage, NR_FILE_PAGES); __dec_node_page_state(oldpage, NR_FILE_PAGES); @@ -1643,7 +1604,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, repeat: swap.val = 0; page = find_lock_entry(mapping, index); - if (radix_tree_exceptional_entry(page)) { + if (xa_is_value(page)) { swap = radix_to_swp_entry(page); page = NULL; } @@ -1718,7 +1679,7 @@ repeat: false); if (!error) { error = shmem_add_to_page_cache(page, mapping, index, - swp_to_radix_entry(swap)); + swp_to_radix_entry(swap), gfp); /* * We already confirmed swap under page lock, and make * no memory allocation here, so usually no possibility @@ -1824,13 +1785,8 @@ alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, inode, PageTransHuge(page)); if (error) goto unacct; - error = radix_tree_maybe_preload_order(gfp & GFP_RECLAIM_MASK, - compound_order(page)); - if (!error) { - error = shmem_add_to_page_cache(page, mapping, hindex, - NULL); - radix_tree_preload_end(); - } + error = shmem_add_to_page_cache(page, mapping, hindex, + NULL, gfp & GFP_RECLAIM_MASK); if (error) { mem_cgroup_cancel_charge(page, memcg, PageTransHuge(page)); @@ -1931,7 +1887,7 @@ unlock: spin_unlock_irq(&info->lock); goto repeat; } - if (error == -EEXIST) /* from above or from radix_tree_insert */ + if (error == -EEXIST) goto repeat; return error; } @@ -2299,11 +2255,8 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, if (ret) goto out_release; - ret = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK); - if (!ret) { - ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL); - radix_tree_preload_end(); - } + ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL, + gfp & GFP_RECLAIM_MASK); if (ret) goto out_release_uncharge; @@ -2548,7 +2501,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to) } /* - * llseek SEEK_DATA or SEEK_HOLE through the radix_tree. + * llseek SEEK_DATA or SEEK_HOLE through the page cache. */ static pgoff_t shmem_seek_hole_data(struct address_space *mapping, pgoff_t index, pgoff_t end, int whence) @@ -2578,7 +2531,7 @@ static pgoff_t shmem_seek_hole_data(struct address_space *mapping, index = indices[i]; } page = pvec.pages[i]; - if (page && !radix_tree_exceptional_entry(page)) { + if (page && !xa_is_value(page)) { if (!PageUptodate(page)) page = NULL; } diff --git a/mm/swap.c b/mm/swap.c index 87a54c8dee34..aa483719922e 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -964,7 +964,7 @@ void pagevec_remove_exceptionals(struct pagevec *pvec) for (i = 0, j = 0; i < pagevec_count(pvec); i++) { struct page *page = pvec->pages[i]; - if (!radix_tree_exceptional_entry(page)) + if (!xa_is_value(page)) pvec->pages[j++] = page; } pvec->nr = j; @@ -1001,7 +1001,7 @@ EXPORT_SYMBOL(pagevec_lookup_range); unsigned pagevec_lookup_range_tag(struct pagevec *pvec, struct address_space *mapping, pgoff_t *index, pgoff_t end, - int tag) + xa_mark_t tag) { pvec->nr = find_get_pages_range_tag(mapping, index, end, tag, PAGEVEC_SIZE, pvec->pages); @@ -1011,7 +1011,7 @@ EXPORT_SYMBOL(pagevec_lookup_range_tag); unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec, struct address_space *mapping, pgoff_t *index, pgoff_t end, - int tag, unsigned max_pages) + xa_mark_t tag, unsigned max_pages) { pvec->nr = find_get_pages_range_tag(mapping, index, end, tag, min_t(unsigned int, max_pages, PAGEVEC_SIZE), pvec->pages); diff --git a/mm/swap_state.c b/mm/swap_state.c index 0d6a7f268d2e..fd2f21e1c60a 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -107,14 +107,15 @@ void show_swap_cache_info(void) } /* - * __add_to_swap_cache resembles add_to_page_cache_locked on swapper_space, + * add_to_swap_cache resembles add_to_page_cache_locked on swapper_space, * but sets SwapCache flag and private instead of mapping and index. */ -int __add_to_swap_cache(struct page *page, swp_entry_t entry) +int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp) { - int error, i, nr = hpage_nr_pages(page); - struct address_space *address_space; + struct address_space *address_space = swap_address_space(entry); pgoff_t idx = swp_offset(entry); + XA_STATE_ORDER(xas, &address_space->i_pages, idx, compound_order(page)); + unsigned long i, nr = 1UL << compound_order(page); VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageSwapCache(page), page); @@ -123,73 +124,52 @@ int __add_to_swap_cache(struct page *page, swp_entry_t entry) page_ref_add(page, nr); SetPageSwapCache(page); - address_space = swap_address_space(entry); - xa_lock_irq(&address_space->i_pages); - for (i = 0; i < nr; i++) { - set_page_private(page + i, entry.val + i); - error = radix_tree_insert(&address_space->i_pages, - idx + i, page + i); - if (unlikely(error)) - break; - } - if (likely(!error)) { + do { + xas_lock_irq(&xas); + xas_create_range(&xas); + if (xas_error(&xas)) + goto unlock; + for (i = 0; i < nr; i++) { + VM_BUG_ON_PAGE(xas.xa_index != idx + i, page); + set_page_private(page + i, entry.val + i); + xas_store(&xas, page + i); + xas_next(&xas); + } address_space->nrpages += nr; __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr); ADD_CACHE_INFO(add_total, nr); - } else { - /* - * Only the context which have set SWAP_HAS_CACHE flag - * would call add_to_swap_cache(). - * So add_to_swap_cache() doesn't returns -EEXIST. - */ - VM_BUG_ON(error == -EEXIST); - set_page_private(page + i, 0UL); - while (i--) { - radix_tree_delete(&address_space->i_pages, idx + i); - set_page_private(page + i, 0UL); - } - ClearPageSwapCache(page); - page_ref_sub(page, nr); - } - xa_unlock_irq(&address_space->i_pages); +unlock: + xas_unlock_irq(&xas); + } while (xas_nomem(&xas, gfp)); - return error; -} + if (!xas_error(&xas)) + return 0; - -int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask) -{ - int error; - - error = radix_tree_maybe_preload_order(gfp_mask, compound_order(page)); - if (!error) { - error = __add_to_swap_cache(page, entry); - radix_tree_preload_end(); - } - return error; + ClearPageSwapCache(page); + page_ref_sub(page, nr); + return xas_error(&xas); } /* * This must be called only on pages that have * been verified to be in the swap cache. */ -void __delete_from_swap_cache(struct page *page) +void __delete_from_swap_cache(struct page *page, swp_entry_t entry) { - struct address_space *address_space; + struct address_space *address_space = swap_address_space(entry); int i, nr = hpage_nr_pages(page); - swp_entry_t entry; - pgoff_t idx; + pgoff_t idx = swp_offset(entry); + XA_STATE(xas, &address_space->i_pages, idx); VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageSwapCache(page), page); VM_BUG_ON_PAGE(PageWriteback(page), page); - entry.val = page_private(page); - address_space = swap_address_space(entry); - idx = swp_offset(entry); for (i = 0; i < nr; i++) { - radix_tree_delete(&address_space->i_pages, idx + i); + void *entry = xas_store(&xas, NULL); + VM_BUG_ON_PAGE(entry != page + i, entry); set_page_private(page + i, 0); + xas_next(&xas); } ClearPageSwapCache(page); address_space->nrpages -= nr; @@ -217,7 +197,7 @@ int add_to_swap(struct page *page) return 0; /* - * Radix-tree node allocations from PF_MEMALLOC contexts could + * XArray node allocations from PF_MEMALLOC contexts could * completely exhaust the page allocator. __GFP_NOMEMALLOC * stops emergency reserves from being allocated. * @@ -229,7 +209,6 @@ int add_to_swap(struct page *page) */ err = add_to_swap_cache(page, entry, __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN); - /* -ENOMEM radix-tree allocation failure */ if (err) /* * add_to_swap_cache() doesn't return -EEXIST, so we can safely @@ -263,14 +242,11 @@ fail: */ void delete_from_swap_cache(struct page *page) { - swp_entry_t entry; - struct address_space *address_space; + swp_entry_t entry = { .val = page_private(page) }; + struct address_space *address_space = swap_address_space(entry); - entry.val = page_private(page); - - address_space = swap_address_space(entry); xa_lock_irq(&address_space->i_pages); - __delete_from_swap_cache(page); + __delete_from_swap_cache(page, entry); xa_unlock_irq(&address_space->i_pages); put_swap_page(page, entry); @@ -413,19 +389,11 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, break; /* Out of memory */ } - /* - * call radix_tree_preload() while we can wait. - */ - err = radix_tree_maybe_preload(gfp_mask & GFP_KERNEL); - if (err) - break; - /* * Swap entry may have been freed since our caller observed it. */ err = swapcache_prepare(entry); if (err == -EEXIST) { - radix_tree_preload_end(); /* * We might race against get_swap_page() and stumble * across a SWAP_HAS_CACHE swap_map entry whose page @@ -433,27 +401,20 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, */ cond_resched(); continue; - } - if (err) { /* swp entry is obsolete ? */ - radix_tree_preload_end(); + } else if (err) /* swp entry is obsolete ? */ break; - } - /* May fail (-ENOMEM) if radix-tree node allocation failed. */ + /* May fail (-ENOMEM) if XArray node allocation failed. */ __SetPageLocked(new_page); __SetPageSwapBacked(new_page); - err = __add_to_swap_cache(new_page, entry); + err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL); if (likely(!err)) { - radix_tree_preload_end(); - /* - * Initiate read into locked page and return. - */ + /* Initiate read into locked page */ SetPageWorkingset(new_page); lru_cache_add_anon(new_page); *new_page_allocated = true; return new_page; } - radix_tree_preload_end(); __ClearPageLocked(new_page); /* * add_to_swap_cache() doesn't return -EEXIST, so we can safely @@ -626,7 +587,7 @@ int init_swap_address_space(unsigned int type, unsigned long nr_pages) return -ENOMEM; for (i = 0; i < nr; i++) { space = spaces + i; - INIT_RADIX_TREE(&space->i_pages, GFP_ATOMIC|__GFP_NOWARN); + xa_init_flags(&space->i_pages, XA_FLAGS_LOCK_IRQ); atomic_set(&space->i_mmap_writable, 0); space->a_ops = &swap_aops; /* swap cache doesn't use writeback related tags */ diff --git a/mm/truncate.c b/mm/truncate.c index 1d2fb2dca96f..45d68e90b703 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -33,15 +33,12 @@ static inline void __clear_shadow_entry(struct address_space *mapping, pgoff_t index, void *entry) { - struct radix_tree_node *node; - void **slot; + XA_STATE(xas, &mapping->i_pages, index); - if (!__radix_tree_lookup(&mapping->i_pages, index, &node, &slot)) + xas_set_update(&xas, workingset_update_node); + if (xas_load(&xas) != entry) return; - if (*slot != entry) - return; - __radix_tree_replace(&mapping->i_pages, node, slot, NULL, - workingset_update_node); + xas_store(&xas, NULL); mapping->nrexceptional--; } @@ -70,7 +67,7 @@ static void truncate_exceptional_pvec_entries(struct address_space *mapping, return; for (j = 0; j < pagevec_count(pvec); j++) - if (radix_tree_exceptional_entry(pvec->pages[j])) + if (xa_is_value(pvec->pages[j])) break; if (j == pagevec_count(pvec)) @@ -85,7 +82,7 @@ static void truncate_exceptional_pvec_entries(struct address_space *mapping, struct page *page = pvec->pages[i]; pgoff_t index = indices[i]; - if (!radix_tree_exceptional_entry(page)) { + if (!xa_is_value(page)) { pvec->pages[j++] = page; continue; } @@ -347,7 +344,7 @@ void truncate_inode_pages_range(struct address_space *mapping, if (index >= end) break; - if (radix_tree_exceptional_entry(page)) + if (xa_is_value(page)) continue; if (!trylock_page(page)) @@ -442,7 +439,7 @@ void truncate_inode_pages_range(struct address_space *mapping, break; } - if (radix_tree_exceptional_entry(page)) + if (xa_is_value(page)) continue; lock_page(page); @@ -561,7 +558,7 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping, if (index > end) break; - if (radix_tree_exceptional_entry(page)) { + if (xa_is_value(page)) { invalidate_exceptional_entry(mapping, index, page); continue; @@ -692,7 +689,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping, if (index > end) break; - if (radix_tree_exceptional_entry(page)) { + if (xa_is_value(page)) { if (!invalidate_exceptional_entry2(mapping, index, page)) ret = -EBUSY; @@ -738,10 +735,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping, index++; } /* - * For DAX we invalidate page tables after invalidating radix tree. We + * For DAX we invalidate page tables after invalidating page cache. We * could invalidate page tables while invalidating each entry however * that would be expensive. And doing range unmapping before doesn't - * work as we have no cheap way to find whether radix tree entry didn't + * work as we have no cheap way to find whether page cache entry didn't * get remapped later. */ if (dax_mapping(mapping)) { diff --git a/mm/vmscan.c b/mm/vmscan.c index 28c9ae5633b9..62ac0c488624 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -751,12 +751,12 @@ static inline int is_page_cache_freeable(struct page *page) { /* * A freeable page cache page is referenced only by the caller - * that isolated the page, the page cache radix tree and - * optional buffer heads at page->private. + * that isolated the page, the page cache and optional buffer + * heads at page->private. */ - int radix_pins = PageTransHuge(page) && PageSwapCache(page) ? + int page_cache_pins = PageTransHuge(page) && PageSwapCache(page) ? HPAGE_PMD_NR : 1; - return page_count(page) - page_has_private(page) == 1 + radix_pins; + return page_count(page) - page_has_private(page) == 1 + page_cache_pins; } static int may_write_to_inode(struct inode *inode, struct scan_control *sc) @@ -932,7 +932,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, if (PageSwapCache(page)) { swp_entry_t swap = { .val = page_private(page) }; mem_cgroup_swapout(page, swap); - __delete_from_swap_cache(page); + __delete_from_swap_cache(page, swap); xa_unlock_irqrestore(&mapping->i_pages, flags); put_swap_page(page, swap); } else { diff --git a/mm/workingset.c b/mm/workingset.c index cbc13d4dfa79..d46f8c92aa2f 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -160,20 +160,20 @@ * and activations is maintained (node->inactive_age). * * On eviction, a snapshot of this counter (along with some bits to - * identify the node) is stored in the now empty page cache radix tree + * identify the node) is stored in the now empty page cache * slot of the evicted page. This is called a shadow entry. * * On cache misses for which there are shadow entries, an eligible * refault distance will immediately activate the refaulting page. */ -#define EVICTION_SHIFT (RADIX_TREE_EXCEPTIONAL_ENTRY + \ +#define EVICTION_SHIFT ((BITS_PER_LONG - BITS_PER_XA_VALUE) + \ 1 + NODES_SHIFT + MEM_CGROUP_ID_SHIFT) #define EVICTION_MASK (~0UL >> EVICTION_SHIFT) /* * Eviction timestamps need to be able to cover the full range of - * actionable refaults. However, bits are tight in the radix tree + * actionable refaults. However, bits are tight in the xarray * entry, and after storing the identifier for the lruvec there might * not be enough left to represent every single actionable refault. In * that case, we have to sacrifice granularity for distance, and group @@ -185,22 +185,21 @@ static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction, bool workingset) { eviction >>= bucket_order; + eviction &= EVICTION_MASK; eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid; eviction = (eviction << NODES_SHIFT) | pgdat->node_id; eviction = (eviction << 1) | workingset; - eviction = (eviction << RADIX_TREE_EXCEPTIONAL_SHIFT); - return (void *)(eviction | RADIX_TREE_EXCEPTIONAL_ENTRY); + return xa_mk_value(eviction); } static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat, unsigned long *evictionp, bool *workingsetp) { - unsigned long entry = (unsigned long)shadow; + unsigned long entry = xa_to_value(shadow); int memcgid, nid; bool workingset; - entry >>= RADIX_TREE_EXCEPTIONAL_SHIFT; workingset = entry & 1; entry >>= 1; nid = entry & ((1UL << NODES_SHIFT) - 1); @@ -367,7 +366,7 @@ out: static struct list_lru shadow_nodes; -void workingset_update_node(struct radix_tree_node *node) +void workingset_update_node(struct xa_node *node) { /* * Track non-empty nodes that contain only shadow entries; @@ -379,7 +378,7 @@ void workingset_update_node(struct radix_tree_node *node) */ VM_WARN_ON_ONCE(!irqs_disabled()); /* For __inc_lruvec_page_state */ - if (node->count && node->count == node->exceptional) { + if (node->count && node->count == node->nr_values) { if (list_empty(&node->private_list)) { list_lru_add(&shadow_nodes, &node->private_list); __inc_lruvec_page_state(virt_to_page(node), @@ -404,7 +403,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, nodes = list_lru_shrink_count(&shadow_nodes, sc); /* - * Approximate a reasonable limit for the radix tree nodes + * Approximate a reasonable limit for the nodes * containing shadow entries. We don't need to keep more * shadow entries than possible pages on the active list, * since refault distances bigger than that are dismissed. @@ -419,11 +418,11 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, * worst-case density of 1/8th. Below that, not all eligible * refaults can be detected anymore. * - * On 64-bit with 7 radix_tree_nodes per page and 64 slots + * On 64-bit with 7 xa_nodes per page and 64 slots * each, this will reclaim shadow entries when they consume * ~1.8% of available memory: * - * PAGE_SIZE / radix_tree_nodes / node_entries * 8 / PAGE_SIZE + * PAGE_SIZE / xa_nodes / node_entries * 8 / PAGE_SIZE */ #ifdef CONFIG_MEMCG if (sc->memcg) { @@ -438,7 +437,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, #endif pages = node_present_pages(sc->nid); - max_nodes = pages >> (RADIX_TREE_MAP_SHIFT - 3); + max_nodes = pages >> (XA_CHUNK_SHIFT - 3); if (!nodes) return SHRINK_EMPTY; @@ -451,11 +450,11 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, static enum lru_status shadow_lru_isolate(struct list_head *item, struct list_lru_one *lru, spinlock_t *lru_lock, - void *arg) + void *arg) __must_hold(lru_lock) { + struct xa_node *node = container_of(item, struct xa_node, private_list); + XA_STATE(xas, node->array, 0); struct address_space *mapping; - struct radix_tree_node *node; - unsigned int i; int ret; /* @@ -463,15 +462,14 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, * the shadow node LRU under the i_pages lock and the * lru_lock. Because the page cache tree is emptied before * the inode can be destroyed, holding the lru_lock pins any - * address_space that has radix tree nodes on the LRU. + * address_space that has nodes on the LRU. * * We can then safely transition to the i_pages lock to * pin only the address_space of the particular node we want * to reclaim, take the node off-LRU, and drop the lru_lock. */ - node = container_of(item, struct radix_tree_node, private_list); - mapping = container_of(node->root, struct address_space, i_pages); + mapping = container_of(node->array, struct address_space, i_pages); /* Coming from the list, invert the lock order */ if (!xa_trylock(&mapping->i_pages)) { @@ -490,29 +488,21 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, * no pages, so we expect to be able to remove them all and * delete and free the empty node afterwards. */ - if (WARN_ON_ONCE(!node->exceptional)) + if (WARN_ON_ONCE(!node->nr_values)) goto out_invalid; - if (WARN_ON_ONCE(node->count != node->exceptional)) - goto out_invalid; - for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) { - if (node->slots[i]) { - if (WARN_ON_ONCE(!radix_tree_exceptional_entry(node->slots[i]))) - goto out_invalid; - if (WARN_ON_ONCE(!node->exceptional)) - goto out_invalid; - if (WARN_ON_ONCE(!mapping->nrexceptional)) - goto out_invalid; - node->slots[i] = NULL; - node->exceptional--; - node->count--; - mapping->nrexceptional--; - } - } - if (WARN_ON_ONCE(node->exceptional)) + if (WARN_ON_ONCE(node->count != node->nr_values)) goto out_invalid; + mapping->nrexceptional -= node->nr_values; + xas.xa_node = xa_parent_locked(&mapping->i_pages, node); + xas.xa_offset = node->offset; + xas.xa_shift = node->shift + XA_CHUNK_SHIFT; + xas_set_update(&xas, workingset_update_node); + /* + * We could store a shadow entry here which was the minimum of the + * shadow entries we were tracking ... + */ + xas_store(&xas, NULL); __inc_lruvec_page_state(virt_to_page(node), WORKINGSET_NODERECLAIM); - __radix_tree_delete_node(&mapping->i_pages, node, - workingset_lookup_update(mapping)); out_invalid: xa_unlock_irq(&mapping->i_pages); diff --git a/tools/include/asm-generic/bitops.h b/tools/include/asm-generic/bitops.h index 9bce3b56b5e7..5d2ab38965cc 100644 --- a/tools/include/asm-generic/bitops.h +++ b/tools/include/asm-generic/bitops.h @@ -27,5 +27,6 @@ #include #include +#include #endif /* __TOOLS_ASM_GENERIC_BITOPS_H */ diff --git a/tools/include/asm-generic/bitops/atomic.h b/tools/include/asm-generic/bitops/atomic.h index 21c41ccd1266..2f6ea28764a7 100644 --- a/tools/include/asm-generic/bitops/atomic.h +++ b/tools/include/asm-generic/bitops/atomic.h @@ -15,13 +15,4 @@ static inline void clear_bit(int nr, unsigned long *addr) addr[nr / __BITS_PER_LONG] &= ~(1UL << (nr % __BITS_PER_LONG)); } -static __always_inline int test_bit(unsigned int nr, const unsigned long *addr) -{ - return ((1UL << (nr % __BITS_PER_LONG)) & - (((unsigned long *)addr)[nr / __BITS_PER_LONG])) != 0; -} - -#define __set_bit(nr, addr) set_bit(nr, addr) -#define __clear_bit(nr, addr) clear_bit(nr, addr) - #endif /* _TOOLS_LINUX_ASM_GENERIC_BITOPS_ATOMIC_H_ */ diff --git a/tools/include/asm-generic/bitops/non-atomic.h b/tools/include/asm-generic/bitops/non-atomic.h new file mode 100644 index 000000000000..7e10c4b50c5d --- /dev/null +++ b/tools/include/asm-generic/bitops/non-atomic.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ + +#include + +/** + * __set_bit - Set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Unlike set_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. + */ +static inline void __set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p |= mask; +} + +static inline void __clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p &= ~mask; +} + +/** + * __change_bit - Toggle a bit in memory + * @nr: the bit to change + * @addr: the address to start counting from + * + * Unlike change_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. + */ +static inline void __change_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p ^= mask; +} + +/** + * __test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old | mask; + return (old & mask) != 0; +} + +/** + * __test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old & ~mask; + return (old & mask) != 0; +} + +/* WARNING: non atomic and it can be reordered! */ +static inline int __test_and_change_bit(int nr, + volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old ^ mask; + return (old & mask) != 0; +} + +/** + * test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static inline int test_bit(int nr, const volatile unsigned long *addr) +{ + return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); +} + +#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h index e63662db131b..05dca5c203f3 100644 --- a/tools/include/linux/bitmap.h +++ b/tools/include/linux/bitmap.h @@ -15,6 +15,7 @@ void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, int bits); int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits); +void bitmap_clear(unsigned long *map, unsigned int start, int len); #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) diff --git a/tools/include/linux/kernel.h b/tools/include/linux/kernel.h index 0ad884452c5c..6935ef94e77a 100644 --- a/tools/include/linux/kernel.h +++ b/tools/include/linux/kernel.h @@ -70,6 +70,7 @@ #define BUG_ON(cond) assert(!(cond)) #endif #endif +#define BUG() BUG_ON(1) #if __BYTE_ORDER == __BIG_ENDIAN #define cpu_to_le16 bswap_16 diff --git a/tools/include/linux/spinlock.h b/tools/include/linux/spinlock.h index 1738c0391da4..c934572d935c 100644 --- a/tools/include/linux/spinlock.h +++ b/tools/include/linux/spinlock.h @@ -8,8 +8,14 @@ #define spinlock_t pthread_mutex_t #define DEFINE_SPINLOCK(x) pthread_mutex_t x = PTHREAD_MUTEX_INITIALIZER #define __SPIN_LOCK_UNLOCKED(x) (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER -#define spin_lock_init(x) pthread_mutex_init(x, NULL) +#define spin_lock_init(x) pthread_mutex_init(x, NULL) +#define spin_lock(x) pthread_mutex_lock(x) +#define spin_unlock(x) pthread_mutex_unlock(x) +#define spin_lock_bh(x) pthread_mutex_lock(x) +#define spin_unlock_bh(x) pthread_mutex_unlock(x) +#define spin_lock_irq(x) pthread_mutex_lock(x) +#define spin_unlock_irq(x) pthread_mutex_unlock(x) #define spin_lock_irqsave(x, f) (void)f, pthread_mutex_lock(x) #define spin_unlock_irqrestore(x, f) (void)f, pthread_mutex_unlock(x) @@ -31,4 +37,6 @@ static inline bool arch_spin_is_locked(arch_spinlock_t *mutex) return true; } +#include + #endif diff --git a/tools/testing/radix-tree/.gitignore b/tools/testing/radix-tree/.gitignore index d4706c0ffceb..3834899b6693 100644 --- a/tools/testing/radix-tree/.gitignore +++ b/tools/testing/radix-tree/.gitignore @@ -4,3 +4,4 @@ idr-test main multiorder radix-tree.c +xarray diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile index 37baecc3766f..acf1afa01c5b 100644 --- a/tools/testing/radix-tree/Makefile +++ b/tools/testing/radix-tree/Makefile @@ -4,8 +4,8 @@ CFLAGS += -I. -I../../include -g -Og -Wall -D_LGPL_SOURCE -fsanitize=address \ -fsanitize=undefined LDFLAGS += -fsanitize=address -fsanitize=undefined LDLIBS+= -lpthread -lurcu -TARGETS = main idr-test multiorder -CORE_OFILES := radix-tree.o idr.o linux.o test.o find_bit.o +TARGETS = main idr-test multiorder xarray +CORE_OFILES := xarray.o radix-tree.o idr.o linux.o test.o find_bit.o bitmap.o OFILES = main.o $(CORE_OFILES) regression1.o regression2.o regression3.o \ tag_check.o multiorder.o idr-test.o iteration_check.o benchmark.o @@ -25,6 +25,8 @@ main: $(OFILES) idr-test.o: ../../../lib/test_ida.c idr-test: idr-test.o $(CORE_OFILES) +xarray: $(CORE_OFILES) + multiorder: multiorder.o $(CORE_OFILES) clean: @@ -35,6 +37,7 @@ vpath %.c ../../lib $(OFILES): Makefile *.h */*.h generated/map-shift.h \ ../../include/linux/*.h \ ../../include/asm/*.h \ + ../../../include/linux/xarray.h \ ../../../include/linux/radix-tree.h \ ../../../include/linux/idr.h @@ -44,8 +47,10 @@ radix-tree.c: ../../../lib/radix-tree.c idr.c: ../../../lib/idr.c sed -e 's/^static //' -e 's/__always_inline //' -e 's/inline //' < $< > $@ +xarray.o: ../../../lib/xarray.c ../../../lib/test_xarray.c + generated/map-shift.h: @if ! grep -qws $(SHIFT) generated/map-shift.h; then \ - echo "#define RADIX_TREE_MAP_SHIFT $(SHIFT)" > \ + echo "#define XA_CHUNK_SHIFT $(SHIFT)" > \ generated/map-shift.h; \ fi diff --git a/tools/testing/radix-tree/benchmark.c b/tools/testing/radix-tree/benchmark.c index 99c40f3ed133..7e195ed8e92d 100644 --- a/tools/testing/radix-tree/benchmark.c +++ b/tools/testing/radix-tree/benchmark.c @@ -17,9 +17,6 @@ #include #include "test.h" -#define for_each_index(i, base, order) \ - for (i = base; i < base + (1 << order); i++) - #define NSEC_PER_SEC 1000000000L static long long benchmark_iter(struct radix_tree_root *root, bool tagged) @@ -61,7 +58,7 @@ again: } static void benchmark_insert(struct radix_tree_root *root, - unsigned long size, unsigned long step, int order) + unsigned long size, unsigned long step) { struct timespec start, finish; unsigned long index; @@ -70,19 +67,19 @@ static void benchmark_insert(struct radix_tree_root *root, clock_gettime(CLOCK_MONOTONIC, &start); for (index = 0 ; index < size ; index += step) - item_insert_order(root, index, order); + item_insert(root, index); clock_gettime(CLOCK_MONOTONIC, &finish); nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC + (finish.tv_nsec - start.tv_nsec); - printv(2, "Size: %8ld, step: %8ld, order: %d, insertion: %15lld ns\n", - size, step, order, nsec); + printv(2, "Size: %8ld, step: %8ld, insertion: %15lld ns\n", + size, step, nsec); } static void benchmark_tagging(struct radix_tree_root *root, - unsigned long size, unsigned long step, int order) + unsigned long size, unsigned long step) { struct timespec start, finish; unsigned long index; @@ -98,138 +95,53 @@ static void benchmark_tagging(struct radix_tree_root *root, nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC + (finish.tv_nsec - start.tv_nsec); - printv(2, "Size: %8ld, step: %8ld, order: %d, tagging: %17lld ns\n", - size, step, order, nsec); + printv(2, "Size: %8ld, step: %8ld, tagging: %17lld ns\n", + size, step, nsec); } static void benchmark_delete(struct radix_tree_root *root, - unsigned long size, unsigned long step, int order) + unsigned long size, unsigned long step) { struct timespec start, finish; - unsigned long index, i; + unsigned long index; long long nsec; clock_gettime(CLOCK_MONOTONIC, &start); for (index = 0 ; index < size ; index += step) - for_each_index(i, index, order) - item_delete(root, i); + item_delete(root, index); clock_gettime(CLOCK_MONOTONIC, &finish); nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC + (finish.tv_nsec - start.tv_nsec); - printv(2, "Size: %8ld, step: %8ld, order: %d, deletion: %16lld ns\n", - size, step, order, nsec); + printv(2, "Size: %8ld, step: %8ld, deletion: %16lld ns\n", + size, step, nsec); } -static void benchmark_size(unsigned long size, unsigned long step, int order) +static void benchmark_size(unsigned long size, unsigned long step) { RADIX_TREE(tree, GFP_KERNEL); long long normal, tagged; - benchmark_insert(&tree, size, step, order); - benchmark_tagging(&tree, size, step, order); + benchmark_insert(&tree, size, step); + benchmark_tagging(&tree, size, step); tagged = benchmark_iter(&tree, true); normal = benchmark_iter(&tree, false); - printv(2, "Size: %8ld, step: %8ld, order: %d, tagged iteration: %8lld ns\n", - size, step, order, tagged); - printv(2, "Size: %8ld, step: %8ld, order: %d, normal iteration: %8lld ns\n", - size, step, order, normal); + printv(2, "Size: %8ld, step: %8ld, tagged iteration: %8lld ns\n", + size, step, tagged); + printv(2, "Size: %8ld, step: %8ld, normal iteration: %8lld ns\n", + size, step, normal); - benchmark_delete(&tree, size, step, order); + benchmark_delete(&tree, size, step); item_kill_tree(&tree); rcu_barrier(); } -static long long __benchmark_split(unsigned long index, - int old_order, int new_order) -{ - struct timespec start, finish; - long long nsec; - RADIX_TREE(tree, GFP_ATOMIC); - - item_insert_order(&tree, index, old_order); - - clock_gettime(CLOCK_MONOTONIC, &start); - radix_tree_split(&tree, index, new_order); - clock_gettime(CLOCK_MONOTONIC, &finish); - nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC + - (finish.tv_nsec - start.tv_nsec); - - item_kill_tree(&tree); - - return nsec; - -} - -static void benchmark_split(unsigned long size, unsigned long step) -{ - int i, j, idx; - long long nsec = 0; - - - for (idx = 0; idx < size; idx += step) { - for (i = 3; i < 11; i++) { - for (j = 0; j < i; j++) { - nsec += __benchmark_split(idx, i, j); - } - } - } - - printv(2, "Size %8ld, step %8ld, split time %10lld ns\n", - size, step, nsec); - -} - -static long long __benchmark_join(unsigned long index, - unsigned order1, unsigned order2) -{ - unsigned long loc; - struct timespec start, finish; - long long nsec; - void *item, *item2 = item_create(index + 1, order1); - RADIX_TREE(tree, GFP_KERNEL); - - item_insert_order(&tree, index, order2); - item = radix_tree_lookup(&tree, index); - - clock_gettime(CLOCK_MONOTONIC, &start); - radix_tree_join(&tree, index + 1, order1, item2); - clock_gettime(CLOCK_MONOTONIC, &finish); - nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC + - (finish.tv_nsec - start.tv_nsec); - - loc = find_item(&tree, item); - if (loc == -1) - free(item); - - item_kill_tree(&tree); - - return nsec; -} - -static void benchmark_join(unsigned long step) -{ - int i, j, idx; - long long nsec = 0; - - for (idx = 0; idx < 1 << 10; idx += step) { - for (i = 1; i < 15; i++) { - for (j = 0; j < i; j++) { - nsec += __benchmark_join(idx, i, j); - } - } - } - - printv(2, "Size %8d, step %8ld, join time %10lld ns\n", - 1 << 10, step, nsec); -} - void benchmark(void) { unsigned long size[] = {1 << 10, 1 << 20, 0}; @@ -242,16 +154,5 @@ void benchmark(void) for (c = 0; size[c]; c++) for (s = 0; step[s]; s++) - benchmark_size(size[c], step[s], 0); - - for (c = 0; size[c]; c++) - for (s = 0; step[s]; s++) - benchmark_size(size[c], step[s] << 9, 9); - - for (c = 0; size[c]; c++) - for (s = 0; step[s]; s++) - benchmark_split(size[c], step[s]); - - for (s = 0; step[s]; s++) - benchmark_join(step[s]); + benchmark_size(size[c], step[s]); } diff --git a/tools/testing/radix-tree/bitmap.c b/tools/testing/radix-tree/bitmap.c new file mode 100644 index 000000000000..66ec4a24a203 --- /dev/null +++ b/tools/testing/radix-tree/bitmap.c @@ -0,0 +1,23 @@ +/* lib/bitmap.c pulls in at least two other files. */ + +#include + +void bitmap_clear(unsigned long *map, unsigned int start, int len) +{ + unsigned long *p = map + BIT_WORD(start); + const unsigned int size = start + len; + int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + + while (len - bits_to_clear >= 0) { + *p &= ~mask_to_clear; + len -= bits_to_clear; + bits_to_clear = BITS_PER_LONG; + mask_to_clear = ~0UL; + p++; + } + if (len) { + mask_to_clear &= BITMAP_LAST_WORD_MASK(size); + *p &= ~mask_to_clear; + } +} diff --git a/tools/testing/radix-tree/generated/autoconf.h b/tools/testing/radix-tree/generated/autoconf.h index cf88dc5b8832..2218b3cc184e 100644 --- a/tools/testing/radix-tree/generated/autoconf.h +++ b/tools/testing/radix-tree/generated/autoconf.h @@ -1 +1 @@ -#define CONFIG_RADIX_TREE_MULTIORDER 1 +#define CONFIG_XARRAY_MULTI 1 diff --git a/tools/testing/radix-tree/idr-test.c b/tools/testing/radix-tree/idr-test.c index 321ba92c70d2..1b63bdb7688f 100644 --- a/tools/testing/radix-tree/idr-test.c +++ b/tools/testing/radix-tree/idr-test.c @@ -19,7 +19,7 @@ #include "test.h" -#define DUMMY_PTR ((void *)0x12) +#define DUMMY_PTR ((void *)0x10) int item_idr_free(int id, void *p, void *data) { @@ -227,6 +227,66 @@ void idr_u32_test(int base) idr_u32_test1(&idr, 0xffffffff); } +static void idr_align_test(struct idr *idr) +{ + char name[] = "Motorola 68000"; + int i, id; + void *entry; + + for (i = 0; i < 9; i++) { + BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i); + idr_for_each_entry(idr, entry, id); + } + idr_destroy(idr); + + for (i = 1; i < 10; i++) { + BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i - 1); + idr_for_each_entry(idr, entry, id); + } + idr_destroy(idr); + + for (i = 2; i < 11; i++) { + BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i - 2); + idr_for_each_entry(idr, entry, id); + } + idr_destroy(idr); + + for (i = 3; i < 12; i++) { + BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i - 3); + idr_for_each_entry(idr, entry, id); + } + idr_destroy(idr); + + for (i = 0; i < 8; i++) { + BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != 0); + BUG_ON(idr_alloc(idr, &name[i + 1], 0, 0, GFP_KERNEL) != 1); + idr_for_each_entry(idr, entry, id); + idr_remove(idr, 1); + idr_for_each_entry(idr, entry, id); + idr_remove(idr, 0); + BUG_ON(!idr_is_empty(idr)); + } + + for (i = 0; i < 8; i++) { + BUG_ON(idr_alloc(idr, NULL, 0, 0, GFP_KERNEL) != 0); + idr_for_each_entry(idr, entry, id); + idr_replace(idr, &name[i], 0); + idr_for_each_entry(idr, entry, id); + BUG_ON(idr_find(idr, 0) != &name[i]); + idr_remove(idr, 0); + } + + for (i = 0; i < 8; i++) { + BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != 0); + BUG_ON(idr_alloc(idr, NULL, 0, 0, GFP_KERNEL) != 1); + idr_remove(idr, 1); + idr_for_each_entry(idr, entry, id); + idr_replace(idr, &name[i + 1], 0); + idr_for_each_entry(idr, entry, id); + idr_remove(idr, 0); + } +} + void idr_checks(void) { unsigned long i; @@ -307,6 +367,7 @@ void idr_checks(void) idr_u32_test(4); idr_u32_test(1); idr_u32_test(0); + idr_align_test(&idr); } #define module_init(x) @@ -344,16 +405,16 @@ void ida_check_conv_user(void) DEFINE_IDA(ida); unsigned long i; - radix_tree_cpu_dead(1); for (i = 0; i < 1000000; i++) { int id = ida_alloc(&ida, GFP_NOWAIT); if (id == -ENOMEM) { - IDA_BUG_ON(&ida, (i % IDA_BITMAP_BITS) != - BITS_PER_LONG - 2); + IDA_BUG_ON(&ida, ((i % IDA_BITMAP_BITS) != + BITS_PER_XA_VALUE) && + ((i % IDA_BITMAP_BITS) != 0)); id = ida_alloc(&ida, GFP_KERNEL); } else { IDA_BUG_ON(&ida, (i % IDA_BITMAP_BITS) == - BITS_PER_LONG - 2); + BITS_PER_XA_VALUE); } IDA_BUG_ON(&ida, id != i); } diff --git a/tools/testing/radix-tree/iteration_check.c b/tools/testing/radix-tree/iteration_check.c index a92bab513701..238db187aa15 100644 --- a/tools/testing/radix-tree/iteration_check.c +++ b/tools/testing/radix-tree/iteration_check.c @@ -1,5 +1,5 @@ /* - * iteration_check.c: test races having to do with radix tree iteration + * iteration_check.c: test races having to do with xarray iteration * Copyright (c) 2016 Intel Corporation * Author: Ross Zwisler * @@ -12,41 +12,54 @@ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ -#include #include #include "test.h" #define NUM_THREADS 5 #define MAX_IDX 100 -#define TAG 0 -#define NEW_TAG 1 +#define TAG XA_MARK_0 +#define NEW_TAG XA_MARK_1 -static pthread_mutex_t tree_lock = PTHREAD_MUTEX_INITIALIZER; static pthread_t threads[NUM_THREADS]; static unsigned int seeds[3]; -static RADIX_TREE(tree, GFP_KERNEL); +static DEFINE_XARRAY(array); static bool test_complete; static int max_order; -/* relentlessly fill the tree with tagged entries */ +void my_item_insert(struct xarray *xa, unsigned long index) +{ + XA_STATE(xas, xa, index); + struct item *item = item_create(index, 0); + int order; + +retry: + xas_lock(&xas); + for (order = max_order; order >= 0; order--) { + xas_set_order(&xas, index, order); + item->order = order; + if (xas_find_conflict(&xas)) + continue; + xas_store(&xas, item); + xas_set_mark(&xas, TAG); + break; + } + xas_unlock(&xas); + if (xas_nomem(&xas, GFP_KERNEL)) + goto retry; + if (order < 0) + free(item); +} + +/* relentlessly fill the array with tagged entries */ static void *add_entries_fn(void *arg) { rcu_register_thread(); while (!test_complete) { unsigned long pgoff; - int order; for (pgoff = 0; pgoff < MAX_IDX; pgoff++) { - pthread_mutex_lock(&tree_lock); - for (order = max_order; order >= 0; order--) { - if (item_insert_order(&tree, pgoff, order) - == 0) { - item_tag_set(&tree, pgoff, TAG); - break; - } - } - pthread_mutex_unlock(&tree_lock); + my_item_insert(&array, pgoff); } } @@ -56,33 +69,25 @@ static void *add_entries_fn(void *arg) } /* - * Iterate over the tagged entries, doing a radix_tree_iter_retry() as we find - * things that have been removed and randomly resetting our iteration to the - * next chunk with radix_tree_iter_resume(). Both radix_tree_iter_retry() and - * radix_tree_iter_resume() cause radix_tree_next_slot() to be called with a - * NULL 'slot' variable. + * Iterate over tagged entries, retrying when we find ourselves in a deleted + * node and randomly pausing the iteration. */ static void *tagged_iteration_fn(void *arg) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &array, 0); + void *entry; rcu_register_thread(); while (!test_complete) { + xas_set(&xas, 0); rcu_read_lock(); - radix_tree_for_each_tagged(slot, &tree, &iter, 0, TAG) { - void *entry = radix_tree_deref_slot(slot); - if (unlikely(!entry)) + xas_for_each_marked(&xas, entry, ULONG_MAX, TAG) { + if (xas_retry(&xas, entry)) continue; - if (radix_tree_deref_retry(entry)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - if (rand_r(&seeds[0]) % 50 == 0) { - slot = radix_tree_iter_resume(slot, &iter); + xas_pause(&xas); rcu_read_unlock(); rcu_barrier(); rcu_read_lock(); @@ -97,33 +102,25 @@ static void *tagged_iteration_fn(void *arg) } /* - * Iterate over the entries, doing a radix_tree_iter_retry() as we find things - * that have been removed and randomly resetting our iteration to the next - * chunk with radix_tree_iter_resume(). Both radix_tree_iter_retry() and - * radix_tree_iter_resume() cause radix_tree_next_slot() to be called with a - * NULL 'slot' variable. + * Iterate over the entries, retrying when we find ourselves in a deleted + * node and randomly pausing the iteration. */ static void *untagged_iteration_fn(void *arg) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &array, 0); + void *entry; rcu_register_thread(); while (!test_complete) { + xas_set(&xas, 0); rcu_read_lock(); - radix_tree_for_each_slot(slot, &tree, &iter, 0) { - void *entry = radix_tree_deref_slot(slot); - if (unlikely(!entry)) + xas_for_each(&xas, entry, ULONG_MAX) { + if (xas_retry(&xas, entry)) continue; - if (radix_tree_deref_retry(entry)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - if (rand_r(&seeds[1]) % 50 == 0) { - slot = radix_tree_iter_resume(slot, &iter); + xas_pause(&xas); rcu_read_unlock(); rcu_barrier(); rcu_read_lock(); @@ -138,7 +135,7 @@ static void *untagged_iteration_fn(void *arg) } /* - * Randomly remove entries to help induce radix_tree_iter_retry() calls in the + * Randomly remove entries to help induce retries in the * two iteration functions. */ static void *remove_entries_fn(void *arg) @@ -147,12 +144,13 @@ static void *remove_entries_fn(void *arg) while (!test_complete) { int pgoff; + struct item *item; pgoff = rand_r(&seeds[2]) % MAX_IDX; - pthread_mutex_lock(&tree_lock); - item_delete(&tree, pgoff); - pthread_mutex_unlock(&tree_lock); + item = xa_erase(&array, pgoff); + if (item) + item_free(item, pgoff); } rcu_unregister_thread(); @@ -165,8 +163,7 @@ static void *tag_entries_fn(void *arg) rcu_register_thread(); while (!test_complete) { - tag_tagged_items(&tree, &tree_lock, 0, MAX_IDX, 10, TAG, - NEW_TAG); + tag_tagged_items(&array, 0, MAX_IDX, 10, TAG, NEW_TAG); } rcu_unregister_thread(); return NULL; @@ -217,5 +214,5 @@ void iteration_test(unsigned order, unsigned test_duration) } } - item_kill_tree(&tree); + item_kill_tree(&array); } diff --git a/tools/testing/radix-tree/linux/bug.h b/tools/testing/radix-tree/linux/bug.h index 23b8ed52f8c8..03dc8a57eb99 100644 --- a/tools/testing/radix-tree/linux/bug.h +++ b/tools/testing/radix-tree/linux/bug.h @@ -1 +1,2 @@ +#include #include "asm/bug.h" diff --git a/tools/testing/radix-tree/linux/kconfig.h b/tools/testing/radix-tree/linux/kconfig.h new file mode 100644 index 000000000000..6c8675859913 --- /dev/null +++ b/tools/testing/radix-tree/linux/kconfig.h @@ -0,0 +1 @@ +#include "../../../../include/linux/kconfig.h" diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h index 426f32f28547..4568248222ae 100644 --- a/tools/testing/radix-tree/linux/kernel.h +++ b/tools/testing/radix-tree/linux/kernel.h @@ -14,7 +14,12 @@ #include "../../../include/linux/kconfig.h" #define printk printf +#define pr_info printk #define pr_debug printk #define pr_cont printk +#define __acquires(x) +#define __releases(x) +#define __must_hold(x) + #endif /* _KERNEL_H */ diff --git a/tools/testing/radix-tree/linux/lockdep.h b/tools/testing/radix-tree/linux/lockdep.h new file mode 100644 index 000000000000..565fccdfe6e9 --- /dev/null +++ b/tools/testing/radix-tree/linux/lockdep.h @@ -0,0 +1,11 @@ +#ifndef _LINUX_LOCKDEP_H +#define _LINUX_LOCKDEP_H +struct lock_class_key { + unsigned int a; +}; + +static inline void lockdep_set_class(spinlock_t *lock, + struct lock_class_key *key) +{ +} +#endif /* _LINUX_LOCKDEP_H */ diff --git a/tools/testing/radix-tree/linux/radix-tree.h b/tools/testing/radix-tree/linux/radix-tree.h index 24f13d27a8da..d1635a5bef02 100644 --- a/tools/testing/radix-tree/linux/radix-tree.h +++ b/tools/testing/radix-tree/linux/radix-tree.h @@ -2,7 +2,6 @@ #ifndef _TEST_RADIX_TREE_H #define _TEST_RADIX_TREE_H -#include "generated/map-shift.h" #include "../../../../include/linux/radix-tree.h" extern int kmalloc_verbose; diff --git a/tools/testing/radix-tree/linux/rcupdate.h b/tools/testing/radix-tree/linux/rcupdate.h index 73ed33658203..fd280b070fdb 100644 --- a/tools/testing/radix-tree/linux/rcupdate.h +++ b/tools/testing/radix-tree/linux/rcupdate.h @@ -6,5 +6,7 @@ #define rcu_dereference_raw(p) rcu_dereference(p) #define rcu_dereference_protected(p, cond) rcu_dereference(p) +#define rcu_dereference_check(p, cond) rcu_dereference(p) +#define RCU_INIT_POINTER(p, v) (p) = (v) #endif diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c index b741686e53d6..77a44c54998f 100644 --- a/tools/testing/radix-tree/main.c +++ b/tools/testing/radix-tree/main.c @@ -214,7 +214,7 @@ void copy_tag_check(void) } // printf("\ncopying tags...\n"); - tagged = tag_tagged_items(&tree, NULL, start, end, ITEMS, 0, 1); + tagged = tag_tagged_items(&tree, start, end, ITEMS, XA_MARK_0, XA_MARK_1); // printf("checking copied tags\n"); assert(tagged == count); @@ -223,7 +223,7 @@ void copy_tag_check(void) /* Copy tags in several rounds */ // printf("\ncopying tags...\n"); tmp = rand() % (count / 10 + 2); - tagged = tag_tagged_items(&tree, NULL, start, end, tmp, 0, 2); + tagged = tag_tagged_items(&tree, start, end, tmp, XA_MARK_0, XA_MARK_2); assert(tagged == count); // printf("%lu %lu %lu\n", tagged, tmp, count); @@ -236,63 +236,6 @@ void copy_tag_check(void) item_kill_tree(&tree); } -static void __locate_check(struct radix_tree_root *tree, unsigned long index, - unsigned order) -{ - struct item *item; - unsigned long index2; - - item_insert_order(tree, index, order); - item = item_lookup(tree, index); - index2 = find_item(tree, item); - if (index != index2) { - printv(2, "index %ld order %d inserted; found %ld\n", - index, order, index2); - abort(); - } -} - -static void __order_0_locate_check(void) -{ - RADIX_TREE(tree, GFP_KERNEL); - int i; - - for (i = 0; i < 50; i++) - __locate_check(&tree, rand() % INT_MAX, 0); - - item_kill_tree(&tree); -} - -static void locate_check(void) -{ - RADIX_TREE(tree, GFP_KERNEL); - unsigned order; - unsigned long offset, index; - - __order_0_locate_check(); - - for (order = 0; order < 20; order++) { - for (offset = 0; offset < (1 << (order + 3)); - offset += (1UL << order)) { - for (index = 0; index < (1UL << (order + 5)); - index += (1UL << order)) { - __locate_check(&tree, index + offset, order); - } - if (find_item(&tree, &tree) != -1) - abort(); - - item_kill_tree(&tree); - } - } - - if (find_item(&tree, &tree) != -1) - abort(); - __locate_check(&tree, -1, 0); - if (find_item(&tree, &tree) != -1) - abort(); - item_kill_tree(&tree); -} - static void single_thread_tests(bool long_run) { int i; @@ -303,10 +246,6 @@ static void single_thread_tests(bool long_run) rcu_barrier(); printv(2, "after multiorder_check: %d allocated, preempt %d\n", nr_allocated, preempt_count); - locate_check(); - rcu_barrier(); - printv(2, "after locate_check: %d allocated, preempt %d\n", - nr_allocated, preempt_count); tag_check(); rcu_barrier(); printv(2, "after tag_check: %d allocated, preempt %d\n", @@ -365,6 +304,7 @@ int main(int argc, char **argv) rcu_register_thread(); radix_tree_init(); + xarray_tests(); regression1_test(); regression2_test(); regression3_test(); diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c index 7bf405638b0b..ff27a74d9762 100644 --- a/tools/testing/radix-tree/multiorder.c +++ b/tools/testing/radix-tree/multiorder.c @@ -20,230 +20,39 @@ #include "test.h" -#define for_each_index(i, base, order) \ - for (i = base; i < base + (1 << order); i++) - -static void __multiorder_tag_test(int index, int order) +static int item_insert_order(struct xarray *xa, unsigned long index, + unsigned order) { - RADIX_TREE(tree, GFP_KERNEL); - int base, err, i; + XA_STATE_ORDER(xas, xa, index, order); + struct item *item = item_create(index, order); - /* our canonical entry */ - base = index & ~((1 << order) - 1); + do { + xas_lock(&xas); + xas_store(&xas, item); + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); - printv(2, "Multiorder tag test with index %d, canonical entry %d\n", - index, base); + if (!xas_error(&xas)) + return 0; - err = item_insert_order(&tree, index, order); - assert(!err); - - /* - * Verify we get collisions for covered indices. We try and fail to - * insert an exceptional entry so we don't leak memory via - * item_insert_order(). - */ - for_each_index(i, base, order) { - err = __radix_tree_insert(&tree, i, order, - (void *)(0xA0 | RADIX_TREE_EXCEPTIONAL_ENTRY)); - assert(err == -EEXIST); - } - - for_each_index(i, base, order) { - assert(!radix_tree_tag_get(&tree, i, 0)); - assert(!radix_tree_tag_get(&tree, i, 1)); - } - - assert(radix_tree_tag_set(&tree, index, 0)); - - for_each_index(i, base, order) { - assert(radix_tree_tag_get(&tree, i, 0)); - assert(!radix_tree_tag_get(&tree, i, 1)); - } - - assert(tag_tagged_items(&tree, NULL, 0, ~0UL, 10, 0, 1) == 1); - assert(radix_tree_tag_clear(&tree, index, 0)); - - for_each_index(i, base, order) { - assert(!radix_tree_tag_get(&tree, i, 0)); - assert(radix_tree_tag_get(&tree, i, 1)); - } - - assert(radix_tree_tag_clear(&tree, index, 1)); - - assert(!radix_tree_tagged(&tree, 0)); - assert(!radix_tree_tagged(&tree, 1)); - - item_kill_tree(&tree); + free(item); + return xas_error(&xas); } -static void __multiorder_tag_test2(unsigned order, unsigned long index2) +void multiorder_iteration(struct xarray *xa) { - RADIX_TREE(tree, GFP_KERNEL); - unsigned long index = (1 << order); - index2 += index; - - assert(item_insert_order(&tree, 0, order) == 0); - assert(item_insert(&tree, index2) == 0); - - assert(radix_tree_tag_set(&tree, 0, 0)); - assert(radix_tree_tag_set(&tree, index2, 0)); - - assert(tag_tagged_items(&tree, NULL, 0, ~0UL, 10, 0, 1) == 2); - - item_kill_tree(&tree); -} - -static void multiorder_tag_tests(void) -{ - int i, j; - - /* test multi-order entry for indices 0-7 with no sibling pointers */ - __multiorder_tag_test(0, 3); - __multiorder_tag_test(5, 3); - - /* test multi-order entry for indices 8-15 with no sibling pointers */ - __multiorder_tag_test(8, 3); - __multiorder_tag_test(15, 3); - - /* - * Our order 5 entry covers indices 0-31 in a tree with height=2. - * This is broken up as follows: - * 0-7: canonical entry - * 8-15: sibling 1 - * 16-23: sibling 2 - * 24-31: sibling 3 - */ - __multiorder_tag_test(0, 5); - __multiorder_tag_test(29, 5); - - /* same test, but with indices 32-63 */ - __multiorder_tag_test(32, 5); - __multiorder_tag_test(44, 5); - - /* - * Our order 8 entry covers indices 0-255 in a tree with height=3. - * This is broken up as follows: - * 0-63: canonical entry - * 64-127: sibling 1 - * 128-191: sibling 2 - * 192-255: sibling 3 - */ - __multiorder_tag_test(0, 8); - __multiorder_tag_test(190, 8); - - /* same test, but with indices 256-511 */ - __multiorder_tag_test(256, 8); - __multiorder_tag_test(300, 8); - - __multiorder_tag_test(0x12345678UL, 8); - - for (i = 1; i < 10; i++) - for (j = 0; j < (10 << i); j++) - __multiorder_tag_test2(i, j); -} - -static void multiorder_check(unsigned long index, int order) -{ - unsigned long i; - unsigned long min = index & ~((1UL << order) - 1); - unsigned long max = min + (1UL << order); - void **slot; - struct item *item2 = item_create(min, order); - RADIX_TREE(tree, GFP_KERNEL); - - printv(2, "Multiorder index %ld, order %d\n", index, order); - - assert(item_insert_order(&tree, index, order) == 0); - - for (i = min; i < max; i++) { - struct item *item = item_lookup(&tree, i); - assert(item != 0); - assert(item->index == index); - } - for (i = 0; i < min; i++) - item_check_absent(&tree, i); - for (i = max; i < 2*max; i++) - item_check_absent(&tree, i); - for (i = min; i < max; i++) - assert(radix_tree_insert(&tree, i, item2) == -EEXIST); - - slot = radix_tree_lookup_slot(&tree, index); - free(*slot); - radix_tree_replace_slot(&tree, slot, item2); - for (i = min; i < max; i++) { - struct item *item = item_lookup(&tree, i); - assert(item != 0); - assert(item->index == min); - } - - assert(item_delete(&tree, min) != 0); - - for (i = 0; i < 2*max; i++) - item_check_absent(&tree, i); -} - -static void multiorder_shrink(unsigned long index, int order) -{ - unsigned long i; - unsigned long max = 1 << order; - RADIX_TREE(tree, GFP_KERNEL); - struct radix_tree_node *node; - - printv(2, "Multiorder shrink index %ld, order %d\n", index, order); - - assert(item_insert_order(&tree, 0, order) == 0); - - node = tree.rnode; - - assert(item_insert(&tree, index) == 0); - assert(node != tree.rnode); - - assert(item_delete(&tree, index) != 0); - assert(node == tree.rnode); - - for (i = 0; i < max; i++) { - struct item *item = item_lookup(&tree, i); - assert(item != 0); - assert(item->index == 0); - } - for (i = max; i < 2*max; i++) - item_check_absent(&tree, i); - - if (!item_delete(&tree, 0)) { - printv(2, "failed to delete index %ld (order %d)\n", index, order); - abort(); - } - - for (i = 0; i < 2*max; i++) - item_check_absent(&tree, i); -} - -static void multiorder_insert_bug(void) -{ - RADIX_TREE(tree, GFP_KERNEL); - - item_insert(&tree, 0); - radix_tree_tag_set(&tree, 0, 0); - item_insert_order(&tree, 3 << 6, 6); - - item_kill_tree(&tree); -} - -void multiorder_iteration(void) -{ - RADIX_TREE(tree, GFP_KERNEL); - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, xa, 0); + struct item *item; int i, j, err; - printv(1, "Multiorder iteration test\n"); - #define NUM_ENTRIES 11 int index[NUM_ENTRIES] = {0, 2, 4, 8, 16, 32, 34, 36, 64, 72, 128}; int order[NUM_ENTRIES] = {1, 1, 2, 3, 4, 1, 0, 1, 3, 0, 7}; + printv(1, "Multiorder iteration test\n"); + for (i = 0; i < NUM_ENTRIES; i++) { - err = item_insert_order(&tree, index[i], order[i]); + err = item_insert_order(xa, index[i], order[i]); assert(!err); } @@ -252,14 +61,14 @@ void multiorder_iteration(void) if (j <= (index[i] | ((1 << order[i]) - 1))) break; - radix_tree_for_each_slot(slot, &tree, &iter, j) { - int height = order[i] / RADIX_TREE_MAP_SHIFT; - int shift = height * RADIX_TREE_MAP_SHIFT; + xas_set(&xas, j); + xas_for_each(&xas, item, ULONG_MAX) { + int height = order[i] / XA_CHUNK_SHIFT; + int shift = height * XA_CHUNK_SHIFT; unsigned long mask = (1UL << order[i]) - 1; - struct item *item = *slot; - assert((iter.index | mask) == (index[i] | mask)); - assert(iter.shift == shift); + assert((xas.xa_index | mask) == (index[i] | mask)); + assert(xas.xa_node->shift == shift); assert(!radix_tree_is_internal_node(item)); assert((item->index | mask) == (index[i] | mask)); assert(item->order == order[i]); @@ -267,18 +76,15 @@ void multiorder_iteration(void) } } - item_kill_tree(&tree); + item_kill_tree(xa); } -void multiorder_tagged_iteration(void) +void multiorder_tagged_iteration(struct xarray *xa) { - RADIX_TREE(tree, GFP_KERNEL); - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, xa, 0); + struct item *item; int i, j; - printv(1, "Multiorder tagged iteration test\n"); - #define MT_NUM_ENTRIES 9 int index[MT_NUM_ENTRIES] = {0, 2, 4, 16, 32, 40, 64, 72, 128}; int order[MT_NUM_ENTRIES] = {1, 0, 2, 4, 3, 1, 3, 0, 7}; @@ -286,13 +92,15 @@ void multiorder_tagged_iteration(void) #define TAG_ENTRIES 7 int tag_index[TAG_ENTRIES] = {0, 4, 16, 40, 64, 72, 128}; - for (i = 0; i < MT_NUM_ENTRIES; i++) - assert(!item_insert_order(&tree, index[i], order[i])); + printv(1, "Multiorder tagged iteration test\n"); - assert(!radix_tree_tagged(&tree, 1)); + for (i = 0; i < MT_NUM_ENTRIES; i++) + assert(!item_insert_order(xa, index[i], order[i])); + + assert(!xa_marked(xa, XA_MARK_1)); for (i = 0; i < TAG_ENTRIES; i++) - assert(radix_tree_tag_set(&tree, tag_index[i], 1)); + xa_set_mark(xa, tag_index[i], XA_MARK_1); for (j = 0; j < 256; j++) { int k; @@ -304,23 +112,23 @@ void multiorder_tagged_iteration(void) break; } - radix_tree_for_each_tagged(slot, &tree, &iter, j, 1) { + xas_set(&xas, j); + xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_1) { unsigned long mask; - struct item *item = *slot; for (k = i; index[k] < tag_index[i]; k++) ; mask = (1UL << order[k]) - 1; - assert((iter.index | mask) == (tag_index[i] | mask)); - assert(!radix_tree_is_internal_node(item)); + assert((xas.xa_index | mask) == (tag_index[i] | mask)); + assert(!xa_is_internal(item)); assert((item->index | mask) == (tag_index[i] | mask)); assert(item->order == order[k]); i++; } } - assert(tag_tagged_items(&tree, NULL, 0, ~0UL, TAG_ENTRIES, 1, 2) == - TAG_ENTRIES); + assert(tag_tagged_items(xa, 0, ULONG_MAX, TAG_ENTRIES, XA_MARK_1, + XA_MARK_2) == TAG_ENTRIES); for (j = 0; j < 256; j++) { int mask, k; @@ -332,297 +140,31 @@ void multiorder_tagged_iteration(void) break; } - radix_tree_for_each_tagged(slot, &tree, &iter, j, 2) { - struct item *item = *slot; + xas_set(&xas, j); + xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_2) { for (k = i; index[k] < tag_index[i]; k++) ; mask = (1 << order[k]) - 1; - assert((iter.index | mask) == (tag_index[i] | mask)); - assert(!radix_tree_is_internal_node(item)); + assert((xas.xa_index | mask) == (tag_index[i] | mask)); + assert(!xa_is_internal(item)); assert((item->index | mask) == (tag_index[i] | mask)); assert(item->order == order[k]); i++; } } - assert(tag_tagged_items(&tree, NULL, 1, ~0UL, MT_NUM_ENTRIES * 2, 1, 0) - == TAG_ENTRIES); + assert(tag_tagged_items(xa, 1, ULONG_MAX, MT_NUM_ENTRIES * 2, XA_MARK_1, + XA_MARK_0) == TAG_ENTRIES); i = 0; - radix_tree_for_each_tagged(slot, &tree, &iter, 0, 0) { - assert(iter.index == tag_index[i]); + xas_set(&xas, 0); + xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_0) { + assert(xas.xa_index == tag_index[i]); i++; } + assert(i == TAG_ENTRIES); - item_kill_tree(&tree); -} - -/* - * Basic join checks: make sure we can't find an entry in the tree after - * a larger entry has replaced it - */ -static void multiorder_join1(unsigned long index, - unsigned order1, unsigned order2) -{ - unsigned long loc; - void *item, *item2 = item_create(index + 1, order1); - RADIX_TREE(tree, GFP_KERNEL); - - item_insert_order(&tree, index, order2); - item = radix_tree_lookup(&tree, index); - radix_tree_join(&tree, index + 1, order1, item2); - loc = find_item(&tree, item); - if (loc == -1) - free(item); - item = radix_tree_lookup(&tree, index + 1); - assert(item == item2); - item_kill_tree(&tree); -} - -/* - * Check that the accounting of exceptional entries is handled correctly - * by joining an exceptional entry to a normal pointer. - */ -static void multiorder_join2(unsigned order1, unsigned order2) -{ - RADIX_TREE(tree, GFP_KERNEL); - struct radix_tree_node *node; - void *item1 = item_create(0, order1); - void *item2; - - item_insert_order(&tree, 0, order2); - radix_tree_insert(&tree, 1 << order2, (void *)0x12UL); - item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL); - assert(item2 == (void *)0x12UL); - assert(node->exceptional == 1); - - item2 = radix_tree_lookup(&tree, 0); - free(item2); - - radix_tree_join(&tree, 0, order1, item1); - item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL); - assert(item2 == item1); - assert(node->exceptional == 0); - item_kill_tree(&tree); -} - -/* - * This test revealed an accounting bug for exceptional entries at one point. - * Nodes were being freed back into the pool with an elevated exception count - * by radix_tree_join() and then radix_tree_split() was failing to zero the - * count of exceptional entries. - */ -static void multiorder_join3(unsigned int order) -{ - RADIX_TREE(tree, GFP_KERNEL); - struct radix_tree_node *node; - void **slot; - struct radix_tree_iter iter; - unsigned long i; - - for (i = 0; i < (1 << order); i++) { - radix_tree_insert(&tree, i, (void *)0x12UL); - } - - radix_tree_join(&tree, 0, order, (void *)0x16UL); - rcu_barrier(); - - radix_tree_split(&tree, 0, 0); - - radix_tree_for_each_slot(slot, &tree, &iter, 0) { - radix_tree_iter_replace(&tree, &iter, slot, (void *)0x12UL); - } - - __radix_tree_lookup(&tree, 0, &node, NULL); - assert(node->exceptional == node->count); - - item_kill_tree(&tree); -} - -static void multiorder_join(void) -{ - int i, j, idx; - - for (idx = 0; idx < 1024; idx = idx * 2 + 3) { - for (i = 1; i < 15; i++) { - for (j = 0; j < i; j++) { - multiorder_join1(idx, i, j); - } - } - } - - for (i = 1; i < 15; i++) { - for (j = 0; j < i; j++) { - multiorder_join2(i, j); - } - } - - for (i = 3; i < 10; i++) { - multiorder_join3(i); - } -} - -static void check_mem(unsigned old_order, unsigned new_order, unsigned alloc) -{ - struct radix_tree_preload *rtp = &radix_tree_preloads; - if (rtp->nr != 0) - printv(2, "split(%u %u) remaining %u\n", old_order, new_order, - rtp->nr); - /* - * Can't check for equality here as some nodes may have been - * RCU-freed while we ran. But we should never finish with more - * nodes allocated since they should have all been preloaded. - */ - if (nr_allocated > alloc) - printv(2, "split(%u %u) allocated %u %u\n", old_order, new_order, - alloc, nr_allocated); -} - -static void __multiorder_split(int old_order, int new_order) -{ - RADIX_TREE(tree, GFP_ATOMIC); - void **slot; - struct radix_tree_iter iter; - unsigned alloc; - struct item *item; - - radix_tree_preload(GFP_KERNEL); - assert(item_insert_order(&tree, 0, old_order) == 0); - radix_tree_preload_end(); - - /* Wipe out the preloaded cache or it'll confuse check_mem() */ - radix_tree_cpu_dead(0); - - item = radix_tree_tag_set(&tree, 0, 2); - - radix_tree_split_preload(old_order, new_order, GFP_KERNEL); - alloc = nr_allocated; - radix_tree_split(&tree, 0, new_order); - check_mem(old_order, new_order, alloc); - radix_tree_for_each_slot(slot, &tree, &iter, 0) { - radix_tree_iter_replace(&tree, &iter, slot, - item_create(iter.index, new_order)); - } - radix_tree_preload_end(); - - item_kill_tree(&tree); - free(item); -} - -static void __multiorder_split2(int old_order, int new_order) -{ - RADIX_TREE(tree, GFP_KERNEL); - void **slot; - struct radix_tree_iter iter; - struct radix_tree_node *node; - void *item; - - __radix_tree_insert(&tree, 0, old_order, (void *)0x12); - - item = __radix_tree_lookup(&tree, 0, &node, NULL); - assert(item == (void *)0x12); - assert(node->exceptional > 0); - - radix_tree_split(&tree, 0, new_order); - radix_tree_for_each_slot(slot, &tree, &iter, 0) { - radix_tree_iter_replace(&tree, &iter, slot, - item_create(iter.index, new_order)); - } - - item = __radix_tree_lookup(&tree, 0, &node, NULL); - assert(item != (void *)0x12); - assert(node->exceptional == 0); - - item_kill_tree(&tree); -} - -static void __multiorder_split3(int old_order, int new_order) -{ - RADIX_TREE(tree, GFP_KERNEL); - void **slot; - struct radix_tree_iter iter; - struct radix_tree_node *node; - void *item; - - __radix_tree_insert(&tree, 0, old_order, (void *)0x12); - - item = __radix_tree_lookup(&tree, 0, &node, NULL); - assert(item == (void *)0x12); - assert(node->exceptional > 0); - - radix_tree_split(&tree, 0, new_order); - radix_tree_for_each_slot(slot, &tree, &iter, 0) { - radix_tree_iter_replace(&tree, &iter, slot, (void *)0x16); - } - - item = __radix_tree_lookup(&tree, 0, &node, NULL); - assert(item == (void *)0x16); - assert(node->exceptional > 0); - - item_kill_tree(&tree); - - __radix_tree_insert(&tree, 0, old_order, (void *)0x12); - - item = __radix_tree_lookup(&tree, 0, &node, NULL); - assert(item == (void *)0x12); - assert(node->exceptional > 0); - - radix_tree_split(&tree, 0, new_order); - radix_tree_for_each_slot(slot, &tree, &iter, 0) { - if (iter.index == (1 << new_order)) - radix_tree_iter_replace(&tree, &iter, slot, - (void *)0x16); - else - radix_tree_iter_replace(&tree, &iter, slot, NULL); - } - - item = __radix_tree_lookup(&tree, 1 << new_order, &node, NULL); - assert(item == (void *)0x16); - assert(node->count == node->exceptional); - do { - node = node->parent; - if (!node) - break; - assert(node->count == 1); - assert(node->exceptional == 0); - } while (1); - - item_kill_tree(&tree); -} - -static void multiorder_split(void) -{ - int i, j; - - for (i = 3; i < 11; i++) - for (j = 0; j < i; j++) { - __multiorder_split(i, j); - __multiorder_split2(i, j); - __multiorder_split3(i, j); - } -} - -static void multiorder_account(void) -{ - RADIX_TREE(tree, GFP_KERNEL); - struct radix_tree_node *node; - void **slot; - - item_insert_order(&tree, 0, 5); - - __radix_tree_insert(&tree, 1 << 5, 5, (void *)0x12); - __radix_tree_lookup(&tree, 0, &node, NULL); - assert(node->count == node->exceptional * 2); - radix_tree_delete(&tree, 1 << 5); - assert(node->exceptional == 0); - - __radix_tree_insert(&tree, 1 << 5, 5, (void *)0x12); - __radix_tree_lookup(&tree, 1 << 5, &node, &slot); - assert(node->count == node->exceptional * 2); - __radix_tree_replace(&tree, node, slot, NULL, NULL); - assert(node->exceptional == 0); - - item_kill_tree(&tree); + item_kill_tree(xa); } bool stop_iteration = false; @@ -645,68 +187,45 @@ static void *creator_func(void *ptr) static void *iterator_func(void *ptr) { - struct radix_tree_root *tree = ptr; - struct radix_tree_iter iter; + XA_STATE(xas, ptr, 0); struct item *item; - void **slot; while (!stop_iteration) { rcu_read_lock(); - radix_tree_for_each_slot(slot, tree, &iter, 0) { - item = radix_tree_deref_slot(slot); - - if (!item) + xas_for_each(&xas, item, ULONG_MAX) { + if (xas_retry(&xas, item)) continue; - if (radix_tree_deref_retry(item)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - item_sanity(item, iter.index); + item_sanity(item, xas.xa_index); } rcu_read_unlock(); } return NULL; } -static void multiorder_iteration_race(void) +static void multiorder_iteration_race(struct xarray *xa) { const int num_threads = sysconf(_SC_NPROCESSORS_ONLN); pthread_t worker_thread[num_threads]; - RADIX_TREE(tree, GFP_KERNEL); int i; - pthread_create(&worker_thread[0], NULL, &creator_func, &tree); + pthread_create(&worker_thread[0], NULL, &creator_func, xa); for (i = 1; i < num_threads; i++) - pthread_create(&worker_thread[i], NULL, &iterator_func, &tree); + pthread_create(&worker_thread[i], NULL, &iterator_func, xa); for (i = 0; i < num_threads; i++) pthread_join(worker_thread[i], NULL); - item_kill_tree(&tree); + item_kill_tree(xa); } +static DEFINE_XARRAY(array); + void multiorder_checks(void) { - int i; - - for (i = 0; i < 20; i++) { - multiorder_check(200, i); - multiorder_check(0, i); - multiorder_check((1UL << i) + 1, i); - } - - for (i = 0; i < 15; i++) - multiorder_shrink((1UL << (i + RADIX_TREE_MAP_SHIFT)), i); - - multiorder_insert_bug(); - multiorder_tag_tests(); - multiorder_iteration(); - multiorder_tagged_iteration(); - multiorder_join(); - multiorder_split(); - multiorder_account(); - multiorder_iteration_race(); + multiorder_iteration(&array); + multiorder_tagged_iteration(&array); + multiorder_iteration_race(&array); radix_tree_cpu_dead(0); } diff --git a/tools/testing/radix-tree/regression1.c b/tools/testing/radix-tree/regression1.c index 0aece092f40e..a61c7bcbc72d 100644 --- a/tools/testing/radix-tree/regression1.c +++ b/tools/testing/radix-tree/regression1.c @@ -44,7 +44,6 @@ #include "regression.h" static RADIX_TREE(mt_tree, GFP_KERNEL); -static pthread_mutex_t mt_lock = PTHREAD_MUTEX_INITIALIZER; struct page { pthread_mutex_t lock; @@ -53,12 +52,12 @@ struct page { unsigned long index; }; -static struct page *page_alloc(void) +static struct page *page_alloc(int index) { struct page *p; p = malloc(sizeof(struct page)); p->count = 1; - p->index = 1; + p->index = index; pthread_mutex_init(&p->lock, NULL); return p; @@ -80,53 +79,33 @@ static void page_free(struct page *p) static unsigned find_get_pages(unsigned long start, unsigned int nr_pages, struct page **pages) { - unsigned int i; - unsigned int ret; - unsigned int nr_found; + XA_STATE(xas, &mt_tree, start); + struct page *page; + unsigned int ret = 0; rcu_read_lock(); -restart: - nr_found = radix_tree_gang_lookup_slot(&mt_tree, - (void ***)pages, NULL, start, nr_pages); - ret = 0; - for (i = 0; i < nr_found; i++) { - struct page *page; -repeat: - page = radix_tree_deref_slot((void **)pages[i]); - if (unlikely(!page)) + xas_for_each(&xas, page, ULONG_MAX) { + if (xas_retry(&xas, page)) continue; - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - /* - * Transient condition which can only trigger - * when entry at index 0 moves out of or back - * to root: none yet gotten, safe to restart. - */ - assert((start | i) == 0); - goto restart; - } - /* - * No exceptional entries are inserted in this test. - */ - assert(0); - } - pthread_mutex_lock(&page->lock); - if (!page->count) { - pthread_mutex_unlock(&page->lock); - goto repeat; - } + if (!page->count) + goto unlock; + /* don't actually update page refcount */ pthread_mutex_unlock(&page->lock); /* Has the page moved? */ - if (unlikely(page != *((void **)pages[i]))) { - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; pages[ret] = page; ret++; + continue; +unlock: + pthread_mutex_unlock(&page->lock); +put_page: + xas_reset(&xas); } rcu_read_unlock(); return ret; @@ -145,30 +124,30 @@ static void *regression1_fn(void *arg) for (j = 0; j < 1000000; j++) { struct page *p; - p = page_alloc(); - pthread_mutex_lock(&mt_lock); + p = page_alloc(0); + xa_lock(&mt_tree); radix_tree_insert(&mt_tree, 0, p); - pthread_mutex_unlock(&mt_lock); + xa_unlock(&mt_tree); - p = page_alloc(); - pthread_mutex_lock(&mt_lock); + p = page_alloc(1); + xa_lock(&mt_tree); radix_tree_insert(&mt_tree, 1, p); - pthread_mutex_unlock(&mt_lock); + xa_unlock(&mt_tree); - pthread_mutex_lock(&mt_lock); + xa_lock(&mt_tree); p = radix_tree_delete(&mt_tree, 1); pthread_mutex_lock(&p->lock); p->count--; pthread_mutex_unlock(&p->lock); - pthread_mutex_unlock(&mt_lock); + xa_unlock(&mt_tree); page_free(p); - pthread_mutex_lock(&mt_lock); + xa_lock(&mt_tree); p = radix_tree_delete(&mt_tree, 0); pthread_mutex_lock(&p->lock); p->count--; pthread_mutex_unlock(&p->lock); - pthread_mutex_unlock(&mt_lock); + xa_unlock(&mt_tree); page_free(p); } } else { diff --git a/tools/testing/radix-tree/regression2.c b/tools/testing/radix-tree/regression2.c index 424b91c77831..f2c7e640a919 100644 --- a/tools/testing/radix-tree/regression2.c +++ b/tools/testing/radix-tree/regression2.c @@ -53,9 +53,9 @@ #include "regression.h" #include "test.h" -#define PAGECACHE_TAG_DIRTY 0 -#define PAGECACHE_TAG_WRITEBACK 1 -#define PAGECACHE_TAG_TOWRITE 2 +#define PAGECACHE_TAG_DIRTY XA_MARK_0 +#define PAGECACHE_TAG_WRITEBACK XA_MARK_1 +#define PAGECACHE_TAG_TOWRITE XA_MARK_2 static RADIX_TREE(mt_tree, GFP_KERNEL); unsigned long page_count = 0; @@ -92,7 +92,7 @@ void regression2_test(void) /* 1. */ start = 0; end = max_slots - 2; - tag_tagged_items(&mt_tree, NULL, start, end, 1, + tag_tagged_items(&mt_tree, start, end, 1, PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE); /* 2. */ diff --git a/tools/testing/radix-tree/regression3.c b/tools/testing/radix-tree/regression3.c index ace2543c3eda..9f9a3b280f56 100644 --- a/tools/testing/radix-tree/regression3.c +++ b/tools/testing/radix-tree/regression3.c @@ -69,21 +69,6 @@ void regression3_test(void) continue; } } - radix_tree_delete(&root, 1); - - first = true; - radix_tree_for_each_contig(slot, &root, &iter, 0) { - printv(2, "contig %ld %p\n", iter.index, *slot); - if (first) { - radix_tree_insert(&root, 1, ptr); - first = false; - } - if (radix_tree_deref_retry(*slot)) { - printv(2, "retry at %ld\n", iter.index); - slot = radix_tree_iter_retry(&iter); - continue; - } - } radix_tree_for_each_slot(slot, &root, &iter, 0) { printv(2, "slot %ld %p\n", iter.index, *slot); @@ -93,14 +78,6 @@ void regression3_test(void) } } - radix_tree_for_each_contig(slot, &root, &iter, 0) { - printv(2, "contig %ld %p\n", iter.index, *slot); - if (!iter.index) { - printv(2, "next at %ld\n", iter.index); - slot = radix_tree_iter_resume(slot, &iter); - } - } - radix_tree_tag_set(&root, 0, 0); radix_tree_tag_set(&root, 1, 0); radix_tree_for_each_tagged(slot, &root, &iter, 0, 0) { diff --git a/tools/testing/radix-tree/tag_check.c b/tools/testing/radix-tree/tag_check.c index 543181e4847b..f898957b1a19 100644 --- a/tools/testing/radix-tree/tag_check.c +++ b/tools/testing/radix-tree/tag_check.c @@ -24,7 +24,7 @@ __simple_checks(struct radix_tree_root *tree, unsigned long index, int tag) item_tag_set(tree, index, tag); ret = item_tag_get(tree, index, tag); assert(ret != 0); - ret = tag_tagged_items(tree, NULL, first, ~0UL, 10, tag, !tag); + ret = tag_tagged_items(tree, first, ~0UL, 10, tag, !tag); assert(ret == 1); ret = item_tag_get(tree, index, !tag); assert(ret != 0); @@ -321,7 +321,7 @@ static void single_check(void) assert(ret == 0); verify_tag_consistency(&tree, 0); verify_tag_consistency(&tree, 1); - ret = tag_tagged_items(&tree, NULL, first, 10, 10, 0, 1); + ret = tag_tagged_items(&tree, first, 10, 10, XA_MARK_0, XA_MARK_1); assert(ret == 1); ret = radix_tree_gang_lookup_tag(&tree, (void **)items, 0, BATCH, 1); assert(ret == 1); @@ -331,34 +331,6 @@ static void single_check(void) item_kill_tree(&tree); } -void radix_tree_clear_tags_test(void) -{ - unsigned long index; - struct radix_tree_node *node; - struct radix_tree_iter iter; - void **slot; - - RADIX_TREE(tree, GFP_KERNEL); - - item_insert(&tree, 0); - item_tag_set(&tree, 0, 0); - __radix_tree_lookup(&tree, 0, &node, &slot); - radix_tree_clear_tags(&tree, node, slot); - assert(item_tag_get(&tree, 0, 0) == 0); - - for (index = 0; index < 1000; index++) { - item_insert(&tree, index); - item_tag_set(&tree, index, 0); - } - - radix_tree_for_each_slot(slot, &tree, &iter, 0) { - radix_tree_clear_tags(&tree, iter.node, slot); - assert(item_tag_get(&tree, iter.index, 0) == 0); - } - - item_kill_tree(&tree); -} - void tag_check(void) { single_check(); @@ -376,5 +348,4 @@ void tag_check(void) thrash_tags(); rcu_barrier(); printv(2, "after thrash_tags: %d allocated\n", nr_allocated); - radix_tree_clear_tags_test(); } diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c index def6015570b2..a15d0512e633 100644 --- a/tools/testing/radix-tree/test.c +++ b/tools/testing/radix-tree/test.c @@ -25,11 +25,6 @@ int item_tag_get(struct radix_tree_root *root, unsigned long index, int tag) return radix_tree_tag_get(root, index, tag); } -int __item_insert(struct radix_tree_root *root, struct item *item) -{ - return __radix_tree_insert(root, item->index, item->order, item); -} - struct item *item_create(unsigned long index, unsigned int order) { struct item *ret = malloc(sizeof(*ret)); @@ -39,21 +34,15 @@ struct item *item_create(unsigned long index, unsigned int order) return ret; } -int item_insert_order(struct radix_tree_root *root, unsigned long index, - unsigned order) +int item_insert(struct radix_tree_root *root, unsigned long index) { - struct item *item = item_create(index, order); - int err = __item_insert(root, item); + struct item *item = item_create(index, 0); + int err = radix_tree_insert(root, item->index, item); if (err) free(item); return err; } -int item_insert(struct radix_tree_root *root, unsigned long index) -{ - return item_insert_order(root, index, 0); -} - void item_sanity(struct item *item, unsigned long index) { unsigned long mask; @@ -63,16 +52,21 @@ void item_sanity(struct item *item, unsigned long index) assert((item->index | mask) == (index | mask)); } +void item_free(struct item *item, unsigned long index) +{ + item_sanity(item, index); + free(item); +} + int item_delete(struct radix_tree_root *root, unsigned long index) { struct item *item = radix_tree_delete(root, index); - if (item) { - item_sanity(item, index); - free(item); - return 1; - } - return 0; + if (!item) + return 0; + + item_free(item, index); + return 1; } static void item_free_rcu(struct rcu_head *head) @@ -82,9 +76,9 @@ static void item_free_rcu(struct rcu_head *head) free(item); } -int item_delete_rcu(struct radix_tree_root *root, unsigned long index) +int item_delete_rcu(struct xarray *xa, unsigned long index) { - struct item *item = radix_tree_delete(root, index); + struct item *item = xa_erase(xa, index); if (item) { item_sanity(item, index); @@ -176,61 +170,32 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start, } /* Use the same pattern as tag_pages_for_writeback() in mm/page-writeback.c */ -int tag_tagged_items(struct radix_tree_root *root, pthread_mutex_t *lock, - unsigned long start, unsigned long end, unsigned batch, - unsigned iftag, unsigned thentag) +int tag_tagged_items(struct xarray *xa, unsigned long start, unsigned long end, + unsigned batch, xa_mark_t iftag, xa_mark_t thentag) { - unsigned long tagged = 0; - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, xa, start); + unsigned int tagged = 0; + struct item *item; if (batch == 0) batch = 1; - if (lock) - pthread_mutex_lock(lock); - radix_tree_for_each_tagged(slot, root, &iter, start, iftag) { - if (iter.index > end) - break; - radix_tree_iter_tag_set(root, &iter, thentag); - tagged++; - if ((tagged % batch) != 0) + xas_lock_irq(&xas); + xas_for_each_marked(&xas, item, end, iftag) { + xas_set_mark(&xas, thentag); + if (++tagged % batch) continue; - slot = radix_tree_iter_resume(slot, &iter); - if (lock) { - pthread_mutex_unlock(lock); - rcu_barrier(); - pthread_mutex_lock(lock); - } + + xas_pause(&xas); + xas_unlock_irq(&xas); + rcu_barrier(); + xas_lock_irq(&xas); } - if (lock) - pthread_mutex_unlock(lock); + xas_unlock_irq(&xas); return tagged; } -/* Use the same pattern as find_swap_entry() in mm/shmem.c */ -unsigned long find_item(struct radix_tree_root *root, void *item) -{ - struct radix_tree_iter iter; - void **slot; - unsigned long found = -1; - unsigned long checked = 0; - - radix_tree_for_each_slot(slot, root, &iter, 0) { - if (*slot == item) { - found = iter.index; - break; - } - checked++; - if ((checked % 4) != 0) - continue; - slot = radix_tree_iter_resume(slot, &iter); - } - - return found; -} - static int verify_node(struct radix_tree_node *slot, unsigned int tag, int tagged) { @@ -281,43 +246,31 @@ static int verify_node(struct radix_tree_node *slot, unsigned int tag, void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag) { - struct radix_tree_node *node = root->rnode; + struct radix_tree_node *node = root->xa_head; if (!radix_tree_is_internal_node(node)) return; verify_node(node, tag, !!root_tag_get(root, tag)); } -void item_kill_tree(struct radix_tree_root *root) +void item_kill_tree(struct xarray *xa) { - struct radix_tree_iter iter; - void **slot; - struct item *items[32]; - int nfound; + XA_STATE(xas, xa, 0); + void *entry; - radix_tree_for_each_slot(slot, root, &iter, 0) { - if (radix_tree_exceptional_entry(*slot)) - radix_tree_delete(root, iter.index); - } - - while ((nfound = radix_tree_gang_lookup(root, (void **)items, 0, 32))) { - int i; - - for (i = 0; i < nfound; i++) { - void *ret; - - ret = radix_tree_delete(root, items[i]->index); - assert(ret == items[i]); - free(items[i]); + xas_for_each(&xas, entry, ULONG_MAX) { + if (!xa_is_value(entry)) { + item_free(entry, xas.xa_index); } + xas_store(&xas, NULL); } - assert(radix_tree_gang_lookup(root, (void **)items, 0, 32) == 0); - assert(root->rnode == NULL); + + assert(xa_empty(xa)); } void tree_verify_min_height(struct radix_tree_root *root, int maxindex) { unsigned shift; - struct radix_tree_node *node = root->rnode; + struct radix_tree_node *node = root->xa_head; if (!radix_tree_is_internal_node(node)) { assert(maxindex == 0); return; diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h index 92d901eacf49..1ee4b2c0ad10 100644 --- a/tools/testing/radix-tree/test.h +++ b/tools/testing/radix-tree/test.h @@ -11,13 +11,11 @@ struct item { }; struct item *item_create(unsigned long index, unsigned int order); -int __item_insert(struct radix_tree_root *root, struct item *item); int item_insert(struct radix_tree_root *root, unsigned long index); void item_sanity(struct item *item, unsigned long index); -int item_insert_order(struct radix_tree_root *root, unsigned long index, - unsigned order); +void item_free(struct item *item, unsigned long index); int item_delete(struct radix_tree_root *root, unsigned long index); -int item_delete_rcu(struct radix_tree_root *root, unsigned long index); +int item_delete_rcu(struct xarray *xa, unsigned long index); struct item *item_lookup(struct radix_tree_root *root, unsigned long index); void item_check_present(struct radix_tree_root *root, unsigned long index); @@ -29,11 +27,10 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start, unsigned long nr, int chunk); void item_kill_tree(struct radix_tree_root *root); -int tag_tagged_items(struct radix_tree_root *, pthread_mutex_t *, - unsigned long start, unsigned long end, unsigned batch, - unsigned iftag, unsigned thentag); -unsigned long find_item(struct radix_tree_root *, void *item); +int tag_tagged_items(struct xarray *, unsigned long start, unsigned long end, + unsigned batch, xa_mark_t iftag, xa_mark_t thentag); +void xarray_tests(void); void tag_check(void); void multiorder_checks(void); void iteration_test(unsigned order, unsigned duration); diff --git a/tools/testing/radix-tree/xarray.c b/tools/testing/radix-tree/xarray.c new file mode 100644 index 000000000000..e61e43efe463 --- /dev/null +++ b/tools/testing/radix-tree/xarray.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * xarray.c: Userspace shim for XArray test-suite + * Copyright (c) 2018 Matthew Wilcox + */ + +#define XA_DEBUG +#include "test.h" + +#define module_init(x) +#define module_exit(x) +#define MODULE_AUTHOR(x) +#define MODULE_LICENSE(x) +#define dump_stack() assert(0) + +#include "../../../lib/xarray.c" +#undef XA_DEBUG +#include "../../../lib/test_xarray.c" + +void xarray_tests(void) +{ + xarray_checks(); + xarray_exit(); +} + +int __weak main(void) +{ + radix_tree_init(); + xarray_tests(); + radix_tree_cpu_dead(1); + rcu_barrier(); + if (nr_allocated) + printf("nr_allocated = %d\n", nr_allocated); + return 0; +}