2005-04-17 00:20:36 +02:00
|
|
|
/*
|
|
|
|
* mm/truncate.c - code for taking down pages from address_spaces
|
|
|
|
*
|
|
|
|
* Copyright (C) 2002, Linus Torvalds
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|
|
|
*
|
2008-10-16 07:01:59 +02:00
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* 10Sep2002 Andrew Morton
|
2005-04-17 00:20:36 +02:00
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|
|
* Initial version.
|
|
|
|
*/
|
|
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|
|
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|
|
#include <linux/kernel.h>
|
2007-10-17 08:29:23 +02:00
|
|
|
#include <linux/backing-dev.h>
|
2016-01-23 00:10:40 +01:00
|
|
|
#include <linux/dax.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 09:04:11 +01:00
|
|
|
#include <linux/gfp.h>
|
2005-04-17 00:20:36 +02:00
|
|
|
#include <linux/mm.h>
|
2006-09-27 10:50:02 +02:00
|
|
|
#include <linux/swap.h>
|
2011-10-16 08:01:52 +02:00
|
|
|
#include <linux/export.h>
|
2005-04-17 00:20:36 +02:00
|
|
|
#include <linux/pagemap.h>
|
2007-05-09 11:35:07 +02:00
|
|
|
#include <linux/highmem.h>
|
2005-04-17 00:20:36 +02:00
|
|
|
#include <linux/pagevec.h>
|
2006-12-10 11:19:31 +01:00
|
|
|
#include <linux/task_io_accounting_ops.h>
|
2005-04-17 00:20:36 +02:00
|
|
|
#include <linux/buffer_head.h> /* grr. try_to_release_page,
|
2005-10-31 00:00:16 +01:00
|
|
|
do_invalidatepage */
|
2017-02-24 23:59:36 +01:00
|
|
|
#include <linux/shmem_fs.h>
|
2011-05-26 18:01:43 +02:00
|
|
|
#include <linux/cleancache.h>
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
#include <linux/rmap.h>
|
2008-10-19 05:26:50 +02:00
|
|
|
#include "internal.h"
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2017-11-16 02:37:44 +01:00
|
|
|
/*
|
|
|
|
* Regular page slots are stabilized by the page lock even without the tree
|
|
|
|
* itself locked. These unlocked entries need verification under the tree
|
|
|
|
* lock.
|
|
|
|
*/
|
|
|
|
static inline void __clear_shadow_entry(struct address_space *mapping,
|
|
|
|
pgoff_t index, void *entry)
|
2014-04-03 23:47:46 +02:00
|
|
|
{
|
2017-11-26 04:52:46 +01:00
|
|
|
XA_STATE(xas, &mapping->i_pages, index);
|
mm: keep page cache radix tree nodes in check
Previously, page cache radix tree nodes were freed after reclaim emptied
out their page pointers. But now reclaim stores shadow entries in their
place, which are only reclaimed when the inodes themselves are
reclaimed. This is problematic for bigger files that are still in use
after they have a significant amount of their cache reclaimed, without
any of those pages actually refaulting. The shadow entries will just
sit there and waste memory. In the worst case, the shadow entries will
accumulate until the machine runs out of memory.
To get this under control, the VM will track radix tree nodes
exclusively containing shadow entries on a per-NUMA node list. Per-NUMA
rather than global because we expect the radix tree nodes themselves to
be allocated node-locally and we want to reduce cross-node references of
otherwise independent cache workloads. A simple shrinker will then
reclaim these nodes on memory pressure.
A few things need to be stored in the radix tree node to implement the
shadow node LRU and allow tree deletions coming from the list:
1. There is no index available that would describe the reverse path
from the node up to the tree root, which is needed to perform a
deletion. To solve this, encode in each node its offset inside the
parent. This can be stored in the unused upper bits of the same
member that stores the node's height at no extra space cost.
2. The number of shadow entries needs to be counted in addition to the
regular entries, to quickly detect when the node is ready to go to
the shadow node LRU list. The current entry count is an unsigned
int but the maximum number of entries is 64, so a shadow counter
can easily be stored in the unused upper bits.
3. Tree modification needs tree lock and tree root, which are located
in the address space, so store an address_space backpointer in the
node. The parent pointer of the node is in a union with the 2-word
rcu_head, so the backpointer comes at no extra cost as well.
4. The node needs to be linked to an LRU list, which requires a list
head inside the node. This does increase the size of the node, but
it does not change the number of objects that fit into a slab page.
[akpm@linux-foundation.org: export the right function]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 23:47:56 +02:00
|
|
|
|
2017-11-26 04:52:46 +01:00
|
|
|
xas_set_update(&xas, workingset_update_node);
|
|
|
|
if (xas_load(&xas) != entry)
|
2017-11-16 02:37:44 +01:00
|
|
|
return;
|
2017-11-26 04:52:46 +01:00
|
|
|
xas_store(&xas, NULL);
|
2016-05-12 18:29:18 +02:00
|
|
|
mapping->nrexceptional--;
|
2017-11-16 02:37:44 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
static void clear_shadow_entry(struct address_space *mapping, pgoff_t index,
|
|
|
|
void *entry)
|
|
|
|
{
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_lock_irq(&mapping->i_pages);
|
2017-11-16 02:37:44 +01:00
|
|
|
__clear_shadow_entry(mapping, index, entry);
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_unlock_irq(&mapping->i_pages);
|
2014-04-03 23:47:46 +02:00
|
|
|
}
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2016-08-10 17:22:44 +02:00
|
|
|
/*
|
2017-11-16 02:37:44 +01:00
|
|
|
* Unconditionally remove exceptional entries. Usually called from truncate
|
|
|
|
* path. Note that the pagevec may be altered by this function by removing
|
|
|
|
* exceptional entries similar to what pagevec_remove_exceptionals does.
|
2016-08-10 17:22:44 +02:00
|
|
|
*/
|
2017-11-16 02:37:44 +01:00
|
|
|
static void truncate_exceptional_pvec_entries(struct address_space *mapping,
|
|
|
|
struct pagevec *pvec, pgoff_t *indices,
|
|
|
|
pgoff_t end)
|
2016-08-10 17:22:44 +02:00
|
|
|
{
|
2017-11-16 02:37:44 +01:00
|
|
|
int i, j;
|
|
|
|
bool dax, lock;
|
|
|
|
|
2016-08-10 17:22:44 +02:00
|
|
|
/* Handled by shmem itself */
|
|
|
|
if (shmem_mapping(mapping))
|
|
|
|
return;
|
|
|
|
|
2017-11-16 02:37:44 +01:00
|
|
|
for (j = 0; j < pagevec_count(pvec); j++)
|
2017-11-03 18:30:42 +01:00
|
|
|
if (xa_is_value(pvec->pages[j]))
|
2017-11-16 02:37:44 +01:00
|
|
|
break;
|
|
|
|
|
|
|
|
if (j == pagevec_count(pvec))
|
2016-08-10 17:22:44 +02:00
|
|
|
return;
|
2017-11-16 02:37:44 +01:00
|
|
|
|
|
|
|
dax = dax_mapping(mapping);
|
|
|
|
lock = !dax && indices[j] < end;
|
|
|
|
if (lock)
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_lock_irq(&mapping->i_pages);
|
2017-11-16 02:37:44 +01:00
|
|
|
|
|
|
|
for (i = j; i < pagevec_count(pvec); i++) {
|
|
|
|
struct page *page = pvec->pages[i];
|
|
|
|
pgoff_t index = indices[i];
|
|
|
|
|
2017-11-03 18:30:42 +01:00
|
|
|
if (!xa_is_value(page)) {
|
2017-11-16 02:37:44 +01:00
|
|
|
pvec->pages[j++] = page;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (index >= end)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
if (unlikely(dax)) {
|
|
|
|
dax_delete_mapping_entry(mapping, index);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
__clear_shadow_entry(mapping, index, page);
|
2016-08-10 17:22:44 +02:00
|
|
|
}
|
2017-11-16 02:37:44 +01:00
|
|
|
|
|
|
|
if (lock)
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_unlock_irq(&mapping->i_pages);
|
2017-11-16 02:37:44 +01:00
|
|
|
pvec->nr = j;
|
2016-08-10 17:22:44 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Invalidate exceptional entry if easily possible. This handles exceptional
|
2017-05-13 00:46:47 +02:00
|
|
|
* entries for invalidate_inode_pages().
|
2016-08-10 17:22:44 +02:00
|
|
|
*/
|
|
|
|
static int invalidate_exceptional_entry(struct address_space *mapping,
|
|
|
|
pgoff_t index, void *entry)
|
|
|
|
{
|
2017-05-13 00:46:47 +02:00
|
|
|
/* Handled by shmem itself, or for DAX we do nothing. */
|
|
|
|
if (shmem_mapping(mapping) || dax_mapping(mapping))
|
2016-08-10 17:22:44 +02:00
|
|
|
return 1;
|
|
|
|
clear_shadow_entry(mapping, index, entry);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Invalidate exceptional entry if clean. This handles exceptional entries for
|
|
|
|
* invalidate_inode_pages2() so for DAX it evicts only clean entries.
|
|
|
|
*/
|
|
|
|
static int invalidate_exceptional_entry2(struct address_space *mapping,
|
|
|
|
pgoff_t index, void *entry)
|
|
|
|
{
|
|
|
|
/* Handled by shmem itself */
|
|
|
|
if (shmem_mapping(mapping))
|
|
|
|
return 1;
|
|
|
|
if (dax_mapping(mapping))
|
|
|
|
return dax_invalidate_mapping_entry_sync(mapping, index);
|
|
|
|
clear_shadow_entry(mapping, index, entry);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2006-08-29 20:05:54 +02:00
|
|
|
/**
|
2008-02-03 17:04:10 +01:00
|
|
|
* do_invalidatepage - invalidate part or all of a page
|
2006-08-29 20:05:54 +02:00
|
|
|
* @page: the page which is affected
|
2013-05-22 05:17:23 +02:00
|
|
|
* @offset: start of the range to invalidate
|
|
|
|
* @length: length of the range to invalidate
|
2006-08-29 20:05:54 +02:00
|
|
|
*
|
|
|
|
* do_invalidatepage() is called when all or part of the page has become
|
|
|
|
* invalidated by a truncate operation.
|
|
|
|
*
|
|
|
|
* do_invalidatepage() does not have to release all buffers, but it must
|
|
|
|
* ensure that no dirty buffer is left outside @offset and that no I/O
|
|
|
|
* is underway against any of the blocks which are outside the truncation
|
|
|
|
* point. Because the caller is about to free (and possibly reuse) those
|
|
|
|
* blocks on-disk.
|
|
|
|
*/
|
2013-05-22 05:17:23 +02:00
|
|
|
void do_invalidatepage(struct page *page, unsigned int offset,
|
|
|
|
unsigned int length)
|
2006-08-29 20:05:54 +02:00
|
|
|
{
|
2013-05-22 05:17:23 +02:00
|
|
|
void (*invalidatepage)(struct page *, unsigned int, unsigned int);
|
|
|
|
|
2006-08-29 20:05:54 +02:00
|
|
|
invalidatepage = page->mapping->a_ops->invalidatepage;
|
[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:45:40 +02:00
|
|
|
#ifdef CONFIG_BLOCK
|
2006-08-29 20:05:54 +02:00
|
|
|
if (!invalidatepage)
|
|
|
|
invalidatepage = block_invalidatepage;
|
[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:45:40 +02:00
|
|
|
#endif
|
2006-08-29 20:05:54 +02:00
|
|
|
if (invalidatepage)
|
2013-05-22 05:17:23 +02:00
|
|
|
(*invalidatepage)(page, offset, length);
|
2006-08-29 20:05:54 +02:00
|
|
|
}
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
/*
|
|
|
|
* If truncate cannot remove the fs-private metadata from the page, the page
|
2008-02-05 07:29:33 +01:00
|
|
|
* becomes orphaned. It will be left on the LRU and may even be mapped into
|
2007-07-19 10:46:59 +02:00
|
|
|
* user pagetables if we're racing with filemap_fault().
|
2005-04-17 00:20:36 +02:00
|
|
|
*
|
|
|
|
* We need to bale out if page->mapping is no longer equal to the original
|
|
|
|
* mapping. This happens a) when the VM reclaimed the page while we waited on
|
2007-02-10 10:45:39 +01:00
|
|
|
* its lock, b) when a concurrent invalidate_mapping_pages got there first and
|
2005-04-17 00:20:36 +02:00
|
|
|
* c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
|
|
|
|
*/
|
2017-11-16 02:37:15 +01:00
|
|
|
static void
|
|
|
|
truncate_cleanup_page(struct address_space *mapping, struct page *page)
|
2005-04-17 00:20:36 +02:00
|
|
|
{
|
2017-11-16 02:37:15 +01:00
|
|
|
if (page_mapped(page)) {
|
2018-02-01 01:17:36 +01:00
|
|
|
pgoff_t nr = PageTransHuge(page) ? HPAGE_PMD_NR : 1;
|
|
|
|
unmap_mapping_pages(mapping, page->index, nr, false);
|
2017-11-16 02:37:15 +01:00
|
|
|
}
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2009-04-03 17:42:36 +02:00
|
|
|
if (page_has_private(page))
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
do_invalidatepage(page, 0, PAGE_SIZE);
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2015-04-15 00:45:27 +02:00
|
|
|
/*
|
|
|
|
* Some filesystems seem to re-dirty the page even after
|
|
|
|
* the VM has canceled the dirty bit (eg ext3 journaling).
|
|
|
|
* Hence dirty accounting check is placed after invalidation.
|
|
|
|
*/
|
2015-05-22 23:13:15 +02:00
|
|
|
cancel_dirty_page(page);
|
2005-04-17 00:20:36 +02:00
|
|
|
ClearPageMappedToDisk(page);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2007-02-10 10:45:39 +01:00
|
|
|
* This is for invalidate_mapping_pages(). That function can be called at
|
2005-04-17 00:20:36 +02:00
|
|
|
* any time, and is not supposed to throw away dirty pages. But pages can
|
2006-09-27 10:50:02 +02:00
|
|
|
* be marked dirty at any time too, so use remove_mapping which safely
|
|
|
|
* discards clean, unused pages.
|
2005-04-17 00:20:36 +02:00
|
|
|
*
|
|
|
|
* Returns non-zero if the page was successfully invalidated.
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
invalidate_complete_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
2006-09-27 10:50:02 +02:00
|
|
|
int ret;
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
if (page->mapping != mapping)
|
|
|
|
return 0;
|
|
|
|
|
2009-04-03 17:42:36 +02:00
|
|
|
if (page_has_private(page) && !try_to_release_page(page, 0))
|
2005-04-17 00:20:36 +02:00
|
|
|
return 0;
|
|
|
|
|
2006-09-27 10:50:02 +02:00
|
|
|
ret = remove_mapping(mapping, page);
|
|
|
|
|
|
|
|
return ret;
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
|
|
|
|
2009-09-16 11:50:12 +02:00
|
|
|
int truncate_inode_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
2016-07-27 00:26:07 +02:00
|
|
|
VM_BUG_ON_PAGE(PageTail(page), page);
|
|
|
|
|
2017-11-16 02:37:15 +01:00
|
|
|
if (page->mapping != mapping)
|
|
|
|
return -EIO;
|
|
|
|
|
|
|
|
truncate_cleanup_page(mapping, page);
|
|
|
|
delete_from_page_cache(page);
|
|
|
|
return 0;
|
2009-09-16 11:50:12 +02:00
|
|
|
}
|
|
|
|
|
2009-09-16 11:50:13 +02:00
|
|
|
/*
|
|
|
|
* Used to get rid of pages on hardware memory corruption.
|
|
|
|
*/
|
|
|
|
int generic_error_remove_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
|
|
|
if (!mapping)
|
|
|
|
return -EINVAL;
|
|
|
|
/*
|
|
|
|
* Only punch for normal data pages for now.
|
|
|
|
* Handling other types like directories would need more auditing.
|
|
|
|
*/
|
|
|
|
if (!S_ISREG(mapping->host->i_mode))
|
|
|
|
return -EIO;
|
|
|
|
return truncate_inode_page(mapping, page);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(generic_error_remove_page);
|
|
|
|
|
2009-09-16 11:50:13 +02:00
|
|
|
/*
|
|
|
|
* Safely invalidate one page from its pagecache mapping.
|
|
|
|
* It only drops clean, unused pages. The page must be locked.
|
|
|
|
*
|
|
|
|
* Returns 1 if the page is successfully invalidated, otherwise 0.
|
|
|
|
*/
|
|
|
|
int invalidate_inode_page(struct page *page)
|
|
|
|
{
|
|
|
|
struct address_space *mapping = page_mapping(page);
|
|
|
|
if (!mapping)
|
|
|
|
return 0;
|
|
|
|
if (PageDirty(page) || PageWriteback(page))
|
|
|
|
return 0;
|
|
|
|
if (page_mapped(page))
|
|
|
|
return 0;
|
|
|
|
return invalidate_complete_page(mapping, page);
|
|
|
|
}
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
/**
|
2012-02-21 03:57:20 +01:00
|
|
|
* truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets
|
2005-04-17 00:20:36 +02:00
|
|
|
* @mapping: mapping to truncate
|
|
|
|
* @lstart: offset from which to truncate
|
2013-05-28 05:32:35 +02:00
|
|
|
* @lend: offset to which to truncate (inclusive)
|
2005-04-17 00:20:36 +02:00
|
|
|
*
|
2006-01-06 09:10:36 +01:00
|
|
|
* Truncate the page cache, removing the pages that are between
|
2013-05-28 05:32:35 +02:00
|
|
|
* specified offsets (and zeroing out partial pages
|
|
|
|
* if lstart or lend + 1 is not page aligned).
|
2005-04-17 00:20:36 +02:00
|
|
|
*
|
|
|
|
* Truncate takes two passes - the first pass is nonblocking. It will not
|
|
|
|
* block on page locks and it will not block on writeback. The second pass
|
|
|
|
* will wait. This is to prevent as much IO as possible in the affected region.
|
|
|
|
* The first pass will remove most pages, so the search cost of the second pass
|
|
|
|
* is low.
|
|
|
|
*
|
|
|
|
* We pass down the cache-hot hint to the page freeing code. Even if the
|
|
|
|
* mapping is large, it is probably the case that the final pages are the most
|
|
|
|
* recently touched, and freeing happens in ascending file offset order.
|
2013-05-28 05:32:35 +02:00
|
|
|
*
|
|
|
|
* Note that since ->invalidatepage() accepts range to invalidate
|
|
|
|
* truncate_inode_pages_range is able to handle cases where lend + 1 is not
|
|
|
|
* page aligned properly.
|
2005-04-17 00:20:36 +02:00
|
|
|
*/
|
2006-01-06 09:10:36 +01:00
|
|
|
void truncate_inode_pages_range(struct address_space *mapping,
|
|
|
|
loff_t lstart, loff_t lend)
|
2005-04-17 00:20:36 +02:00
|
|
|
{
|
2013-05-28 05:32:35 +02:00
|
|
|
pgoff_t start; /* inclusive */
|
|
|
|
pgoff_t end; /* exclusive */
|
|
|
|
unsigned int partial_start; /* inclusive */
|
|
|
|
unsigned int partial_end; /* exclusive */
|
|
|
|
struct pagevec pvec;
|
2014-04-03 23:47:46 +02:00
|
|
|
pgoff_t indices[PAGEVEC_SIZE];
|
2013-05-28 05:32:35 +02:00
|
|
|
pgoff_t index;
|
|
|
|
int i;
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2016-01-23 00:10:40 +01:00
|
|
|
if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
|
2017-05-03 23:56:09 +02:00
|
|
|
goto out;
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2013-05-28 05:32:35 +02:00
|
|
|
/* Offsets within partial pages */
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
partial_start = lstart & (PAGE_SIZE - 1);
|
|
|
|
partial_end = (lend + 1) & (PAGE_SIZE - 1);
|
2013-05-28 05:32:35 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* 'start' and 'end' always covers the range of pages to be fully
|
|
|
|
* truncated. Partial pages are covered with 'partial_start' at the
|
|
|
|
* start of the range and 'partial_end' at the end of the range.
|
|
|
|
* Note that 'end' is exclusive while 'lend' is inclusive.
|
|
|
|
*/
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
start = (lstart + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
2013-05-28 05:32:35 +02:00
|
|
|
if (lend == -1)
|
|
|
|
/*
|
|
|
|
* lend == -1 indicates end-of-file so we have to set 'end'
|
|
|
|
* to the highest possible pgoff_t and since the type is
|
|
|
|
* unsigned we're using -1.
|
|
|
|
*/
|
|
|
|
end = -1;
|
|
|
|
else
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
end = (lend + 1) >> PAGE_SHIFT;
|
2006-01-06 09:10:36 +01:00
|
|
|
|
2017-11-16 02:37:52 +01:00
|
|
|
pagevec_init(&pvec);
|
2011-07-26 02:12:25 +02:00
|
|
|
index = start;
|
2014-04-03 23:47:46 +02:00
|
|
|
while (index < end && pagevec_lookup_entries(&pvec, mapping, index,
|
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE),
|
|
|
|
indices)) {
|
2017-11-16 02:37:33 +01:00
|
|
|
/*
|
|
|
|
* Pagevec array has exceptional entries and we may also fail
|
|
|
|
* to lock some pages. So we store pages that can be deleted
|
|
|
|
* in a new pagevec.
|
|
|
|
*/
|
|
|
|
struct pagevec locked_pvec;
|
|
|
|
|
2017-11-16 02:37:52 +01:00
|
|
|
pagevec_init(&locked_pvec);
|
2005-04-17 00:20:36 +02:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
|
|
struct page *page = pvec.pages[i];
|
|
|
|
|
2011-07-26 02:12:25 +02:00
|
|
|
/* We rely upon deletion not changing page->index */
|
2014-04-03 23:47:46 +02:00
|
|
|
index = indices[i];
|
2013-05-28 05:32:35 +02:00
|
|
|
if (index >= end)
|
2006-01-06 09:10:36 +01:00
|
|
|
break;
|
|
|
|
|
2017-11-03 18:30:42 +01:00
|
|
|
if (xa_is_value(page))
|
2014-04-03 23:47:46 +02:00
|
|
|
continue;
|
|
|
|
|
2008-08-02 12:01:03 +02:00
|
|
|
if (!trylock_page(page))
|
2005-04-17 00:20:36 +02:00
|
|
|
continue;
|
2016-12-01 00:54:19 +01:00
|
|
|
WARN_ON(page_to_index(page) != index);
|
2005-04-17 00:20:36 +02:00
|
|
|
if (PageWriteback(page)) {
|
|
|
|
unlock_page(page);
|
|
|
|
continue;
|
|
|
|
}
|
2017-11-16 02:37:33 +01:00
|
|
|
if (page->mapping != mapping) {
|
|
|
|
unlock_page(page);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
pagevec_add(&locked_pvec, page);
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2017-11-16 02:37:33 +01:00
|
|
|
for (i = 0; i < pagevec_count(&locked_pvec); i++)
|
|
|
|
truncate_cleanup_page(mapping, locked_pvec.pages[i]);
|
|
|
|
delete_from_page_cache_batch(mapping, &locked_pvec);
|
|
|
|
for (i = 0; i < pagevec_count(&locked_pvec); i++)
|
|
|
|
unlock_page(locked_pvec.pages[i]);
|
2017-11-16 02:37:44 +01:00
|
|
|
truncate_exceptional_pvec_entries(mapping, &pvec, indices, end);
|
2005-04-17 00:20:36 +02:00
|
|
|
pagevec_release(&pvec);
|
|
|
|
cond_resched();
|
2011-07-26 02:12:25 +02:00
|
|
|
index++;
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2013-05-28 05:32:35 +02:00
|
|
|
if (partial_start) {
|
2005-04-17 00:20:36 +02:00
|
|
|
struct page *page = find_lock_page(mapping, start - 1);
|
|
|
|
if (page) {
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
unsigned int top = PAGE_SIZE;
|
2013-05-28 05:32:35 +02:00
|
|
|
if (start > end) {
|
|
|
|
/* Truncation within a single page */
|
|
|
|
top = partial_end;
|
|
|
|
partial_end = 0;
|
|
|
|
}
|
2005-04-17 00:20:36 +02:00
|
|
|
wait_on_page_writeback(page);
|
2013-05-28 05:32:35 +02:00
|
|
|
zero_user_segment(page, partial_start, top);
|
|
|
|
cleancache_invalidate_page(mapping, page);
|
|
|
|
if (page_has_private(page))
|
|
|
|
do_invalidatepage(page, partial_start,
|
|
|
|
top - partial_start);
|
2005-04-17 00:20:36 +02:00
|
|
|
unlock_page(page);
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
put_page(page);
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
|
|
|
}
|
2013-05-28 05:32:35 +02:00
|
|
|
if (partial_end) {
|
|
|
|
struct page *page = find_lock_page(mapping, end);
|
|
|
|
if (page) {
|
|
|
|
wait_on_page_writeback(page);
|
|
|
|
zero_user_segment(page, 0, partial_end);
|
|
|
|
cleancache_invalidate_page(mapping, page);
|
|
|
|
if (page_has_private(page))
|
|
|
|
do_invalidatepage(page, 0,
|
|
|
|
partial_end);
|
|
|
|
unlock_page(page);
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
put_page(page);
|
2013-05-28 05:32:35 +02:00
|
|
|
}
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* If the truncation happened within a single page no pages
|
|
|
|
* will be released, just zeroed, so we can bail out now.
|
|
|
|
*/
|
|
|
|
if (start >= end)
|
2017-05-03 23:56:09 +02:00
|
|
|
goto out;
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2011-07-26 02:12:25 +02:00
|
|
|
index = start;
|
2005-04-17 00:20:36 +02:00
|
|
|
for ( ; ; ) {
|
|
|
|
cond_resched();
|
2014-04-03 23:47:46 +02:00
|
|
|
if (!pagevec_lookup_entries(&pvec, mapping, index,
|
2014-07-23 23:00:15 +02:00
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE), indices)) {
|
|
|
|
/* If all gone from start onwards, we're done */
|
2011-07-26 02:12:25 +02:00
|
|
|
if (index == start)
|
2005-04-17 00:20:36 +02:00
|
|
|
break;
|
2014-07-23 23:00:15 +02:00
|
|
|
/* Otherwise restart to make sure all gone */
|
2011-07-26 02:12:25 +02:00
|
|
|
index = start;
|
2005-04-17 00:20:36 +02:00
|
|
|
continue;
|
|
|
|
}
|
2014-04-03 23:47:46 +02:00
|
|
|
if (index == start && indices[0] >= end) {
|
2014-07-23 23:00:15 +02:00
|
|
|
/* All gone out of hole to be punched, we're done */
|
2014-04-03 23:47:46 +02:00
|
|
|
pagevec_remove_exceptionals(&pvec);
|
2006-01-06 09:10:36 +01:00
|
|
|
pagevec_release(&pvec);
|
|
|
|
break;
|
|
|
|
}
|
2017-11-16 02:37:44 +01:00
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
|
|
struct page *page = pvec.pages[i];
|
|
|
|
|
2011-07-26 02:12:25 +02:00
|
|
|
/* We rely upon deletion not changing page->index */
|
2014-04-03 23:47:46 +02:00
|
|
|
index = indices[i];
|
2014-07-23 23:00:15 +02:00
|
|
|
if (index >= end) {
|
|
|
|
/* Restart punch to make sure all gone */
|
|
|
|
index = start - 1;
|
2006-01-06 09:10:36 +01:00
|
|
|
break;
|
2014-07-23 23:00:15 +02:00
|
|
|
}
|
2011-07-26 02:12:25 +02:00
|
|
|
|
2017-11-03 18:30:42 +01:00
|
|
|
if (xa_is_value(page))
|
2014-04-03 23:47:46 +02:00
|
|
|
continue;
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
lock_page(page);
|
2016-12-01 00:54:19 +01:00
|
|
|
WARN_ON(page_to_index(page) != index);
|
2005-04-17 00:20:36 +02:00
|
|
|
wait_on_page_writeback(page);
|
2009-09-16 11:50:12 +02:00
|
|
|
truncate_inode_page(mapping, page);
|
2005-04-17 00:20:36 +02:00
|
|
|
unlock_page(page);
|
|
|
|
}
|
2017-11-16 02:37:44 +01:00
|
|
|
truncate_exceptional_pvec_entries(mapping, &pvec, indices, end);
|
2005-04-17 00:20:36 +02:00
|
|
|
pagevec_release(&pvec);
|
2011-07-26 02:12:25 +02:00
|
|
|
index++;
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2017-05-03 23:56:09 +02:00
|
|
|
|
|
|
|
out:
|
2011-09-21 17:56:28 +02:00
|
|
|
cleancache_invalidate_inode(mapping);
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2006-01-06 09:10:36 +01:00
|
|
|
EXPORT_SYMBOL(truncate_inode_pages_range);
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2006-01-06 09:10:36 +01:00
|
|
|
/**
|
|
|
|
* truncate_inode_pages - truncate *all* the pages from an offset
|
|
|
|
* @mapping: mapping to truncate
|
|
|
|
* @lstart: offset from which to truncate
|
|
|
|
*
|
2006-01-10 00:59:24 +01:00
|
|
|
* Called under (and serialised by) inode->i_mutex.
|
2011-06-28 01:18:10 +02:00
|
|
|
*
|
|
|
|
* Note: When this function returns, there can be a page in the process of
|
|
|
|
* deletion (inside __delete_from_page_cache()) in the specified range. Thus
|
|
|
|
* mapping->nrpages can be non-zero when this function returns even after
|
|
|
|
* truncation of the whole mapping.
|
2006-01-06 09:10:36 +01:00
|
|
|
*/
|
|
|
|
void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
|
|
|
|
{
|
|
|
|
truncate_inode_pages_range(mapping, lstart, (loff_t)-1);
|
|
|
|
}
|
2005-04-17 00:20:36 +02:00
|
|
|
EXPORT_SYMBOL(truncate_inode_pages);
|
|
|
|
|
2014-04-03 23:47:49 +02:00
|
|
|
/**
|
|
|
|
* truncate_inode_pages_final - truncate *all* pages before inode dies
|
|
|
|
* @mapping: mapping to truncate
|
|
|
|
*
|
|
|
|
* Called under (and serialized by) inode->i_mutex.
|
|
|
|
*
|
|
|
|
* Filesystems have to use this in the .evict_inode path to inform the
|
|
|
|
* VM that this is the final truncate and the inode is going away.
|
|
|
|
*/
|
|
|
|
void truncate_inode_pages_final(struct address_space *mapping)
|
|
|
|
{
|
2016-01-23 00:10:40 +01:00
|
|
|
unsigned long nrexceptional;
|
2014-04-03 23:47:49 +02:00
|
|
|
unsigned long nrpages;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Page reclaim can not participate in regular inode lifetime
|
|
|
|
* management (can't call iput()) and thus can race with the
|
|
|
|
* inode teardown. Tell it when the address space is exiting,
|
|
|
|
* so that it does not install eviction information after the
|
|
|
|
* final truncate has begun.
|
|
|
|
*/
|
|
|
|
mapping_set_exiting(mapping);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* When reclaim installs eviction entries, it increases
|
2016-01-23 00:10:40 +01:00
|
|
|
* nrexceptional first, then decreases nrpages. Make sure we see
|
2014-04-03 23:47:49 +02:00
|
|
|
* this in the right order or we might miss an entry.
|
|
|
|
*/
|
|
|
|
nrpages = mapping->nrpages;
|
|
|
|
smp_rmb();
|
2016-01-23 00:10:40 +01:00
|
|
|
nrexceptional = mapping->nrexceptional;
|
2014-04-03 23:47:49 +02:00
|
|
|
|
2016-01-23 00:10:40 +01:00
|
|
|
if (nrpages || nrexceptional) {
|
2014-04-03 23:47:49 +02:00
|
|
|
/*
|
|
|
|
* As truncation uses a lockless tree lookup, cycle
|
|
|
|
* the tree lock to make sure any ongoing tree
|
|
|
|
* modification that does not see AS_EXITING is
|
|
|
|
* completed before starting the final truncate.
|
|
|
|
*/
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_lock_irq(&mapping->i_pages);
|
|
|
|
xa_unlock_irq(&mapping->i_pages);
|
2014-04-03 23:47:49 +02:00
|
|
|
|
|
|
|
truncate_inode_pages(mapping, 0);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(truncate_inode_pages_final);
|
|
|
|
|
2009-06-17 00:32:59 +02:00
|
|
|
/**
|
|
|
|
* invalidate_mapping_pages - Invalidate all the unlocked pages of one inode
|
|
|
|
* @mapping: the address_space which holds the pages to invalidate
|
|
|
|
* @start: the offset 'from' which to invalidate
|
|
|
|
* @end: the offset 'to' which to invalidate (inclusive)
|
|
|
|
*
|
|
|
|
* This function only removes the unlocked pages, if you want to
|
|
|
|
* remove all the pages of one inode, you must call truncate_inode_pages.
|
|
|
|
*
|
|
|
|
* invalidate_mapping_pages() will not block on IO activity. It will not
|
|
|
|
* invalidate pages which are dirty, locked, under writeback or mapped into
|
|
|
|
* pagetables.
|
|
|
|
*/
|
|
|
|
unsigned long invalidate_mapping_pages(struct address_space *mapping,
|
2011-03-23 00:32:52 +01:00
|
|
|
pgoff_t start, pgoff_t end)
|
2005-04-17 00:20:36 +02:00
|
|
|
{
|
2014-04-03 23:47:46 +02:00
|
|
|
pgoff_t indices[PAGEVEC_SIZE];
|
2005-04-17 00:20:36 +02:00
|
|
|
struct pagevec pvec;
|
2011-07-26 02:12:25 +02:00
|
|
|
pgoff_t index = start;
|
2011-03-23 00:32:52 +01:00
|
|
|
unsigned long ret;
|
|
|
|
unsigned long count = 0;
|
2005-04-17 00:20:36 +02:00
|
|
|
int i;
|
|
|
|
|
2017-11-16 02:37:52 +01:00
|
|
|
pagevec_init(&pvec);
|
2014-04-03 23:47:46 +02:00
|
|
|
while (index <= end && pagevec_lookup_entries(&pvec, mapping, index,
|
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1,
|
|
|
|
indices)) {
|
2005-04-17 00:20:36 +02:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
|
|
struct page *page = pvec.pages[i];
|
2006-06-23 11:05:48 +02:00
|
|
|
|
2011-07-26 02:12:25 +02:00
|
|
|
/* We rely upon deletion not changing page->index */
|
2014-04-03 23:47:46 +02:00
|
|
|
index = indices[i];
|
2011-07-26 02:12:25 +02:00
|
|
|
if (index > end)
|
|
|
|
break;
|
2006-06-23 11:05:48 +02:00
|
|
|
|
2017-11-03 18:30:42 +01:00
|
|
|
if (xa_is_value(page)) {
|
2016-08-10 17:22:44 +02:00
|
|
|
invalidate_exceptional_entry(mapping, index,
|
|
|
|
page);
|
2014-04-03 23:47:46 +02:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2011-07-26 02:12:25 +02:00
|
|
|
if (!trylock_page(page))
|
|
|
|
continue;
|
2016-07-27 00:26:07 +02:00
|
|
|
|
2016-12-01 00:54:19 +01:00
|
|
|
WARN_ON(page_to_index(page) != index);
|
2016-07-27 00:26:07 +02:00
|
|
|
|
|
|
|
/* Middle of THP: skip */
|
|
|
|
if (PageTransTail(page)) {
|
|
|
|
unlock_page(page);
|
|
|
|
continue;
|
|
|
|
} else if (PageTransHuge(page)) {
|
|
|
|
index += HPAGE_PMD_NR - 1;
|
|
|
|
i += HPAGE_PMD_NR - 1;
|
2017-07-11 00:48:59 +02:00
|
|
|
/*
|
|
|
|
* 'end' is in the middle of THP. Don't
|
|
|
|
* invalidate the page as the part outside of
|
|
|
|
* 'end' could be still useful.
|
|
|
|
*/
|
|
|
|
if (index > end) {
|
|
|
|
unlock_page(page);
|
2016-07-27 00:26:07 +02:00
|
|
|
continue;
|
2017-07-11 00:48:59 +02:00
|
|
|
}
|
2016-07-27 00:26:07 +02:00
|
|
|
}
|
|
|
|
|
2011-03-23 00:32:52 +01:00
|
|
|
ret = invalidate_inode_page(page);
|
2005-04-17 00:20:36 +02:00
|
|
|
unlock_page(page);
|
2011-03-23 00:32:52 +01:00
|
|
|
/*
|
|
|
|
* Invalidation is a hint that the page is no longer
|
|
|
|
* of interest and try to speed up its reclaim.
|
|
|
|
*/
|
|
|
|
if (!ret)
|
2015-04-16 01:13:26 +02:00
|
|
|
deactivate_file_page(page);
|
2011-03-23 00:32:52 +01:00
|
|
|
count += ret;
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2014-04-03 23:47:46 +02:00
|
|
|
pagevec_remove_exceptionals(&pvec);
|
2005-04-17 00:20:36 +02:00
|
|
|
pagevec_release(&pvec);
|
2009-06-17 00:32:59 +02:00
|
|
|
cond_resched();
|
2011-07-26 02:12:25 +02:00
|
|
|
index++;
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2011-03-23 00:32:52 +01:00
|
|
|
return count;
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2007-02-10 10:45:38 +01:00
|
|
|
EXPORT_SYMBOL(invalidate_mapping_pages);
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2006-10-01 08:29:29 +02:00
|
|
|
/*
|
|
|
|
* This is like invalidate_complete_page(), except it ignores the page's
|
|
|
|
* refcount. We do this because invalidate_inode_pages2() needs stronger
|
|
|
|
* invalidation guarantees, and cannot afford to leave pages behind because
|
2007-07-16 08:38:09 +02:00
|
|
|
* shrink_page_list() has a temp ref on them, or because they're transiently
|
|
|
|
* sitting in the lru_cache_add() pagevecs.
|
2006-10-01 08:29:29 +02:00
|
|
|
*/
|
|
|
|
static int
|
|
|
|
invalidate_complete_page2(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
memcg: add per cgroup dirty page accounting
When modifying PG_Dirty on cached file pages, update the new
MEM_CGROUP_STAT_DIRTY counter. This is done in the same places where
global NR_FILE_DIRTY is managed. The new memcg stat is visible in the
per memcg memory.stat cgroupfs file. The most recent past attempt at
this was http://thread.gmane.org/gmane.linux.kernel.cgroups/8632
The new accounting supports future efforts to add per cgroup dirty
page throttling and writeback. It also helps an administrator break
down a container's memory usage and provides evidence to understand
memcg oom kills (the new dirty count is included in memcg oom kill
messages).
The ability to move page accounting between memcg
(memory.move_charge_at_immigrate) makes this accounting more
complicated than the global counter. The existing
mem_cgroup_{begin,end}_page_stat() lock is used to serialize move
accounting with stat updates.
Typical update operation:
memcg = mem_cgroup_begin_page_stat(page)
if (TestSetPageDirty()) {
[...]
mem_cgroup_update_page_stat(memcg)
}
mem_cgroup_end_page_stat(memcg)
Summary of mem_cgroup_end_page_stat() overhead:
- Without CONFIG_MEMCG it's a no-op
- With CONFIG_MEMCG and no inter memcg task movement, it's just
rcu_read_lock()
- With CONFIG_MEMCG and inter memcg task movement, it's
rcu_read_lock() + spin_lock_irqsave()
A memcg parameter is added to several routines because their callers
now grab mem_cgroup_begin_page_stat() which returns the memcg later
needed by for mem_cgroup_update_page_stat().
Because mem_cgroup_begin_page_stat() may disable interrupts, some
adjustments are needed:
- move __mark_inode_dirty() from __set_page_dirty() to its caller.
__mark_inode_dirty() locking does not want interrupts disabled.
- use spin_lock_irqsave(tree_lock) rather than spin_lock_irq() in
__delete_from_page_cache(), replace_page_cache_page(),
invalidate_complete_page2(), and __remove_mapping().
text data bss dec hex filename
8925147 1774832 1785856 12485835 be84cb vmlinux-!CONFIG_MEMCG-before
8925339 1774832 1785856 12486027 be858b vmlinux-!CONFIG_MEMCG-after
+192 text bytes
8965977 1784992 1785856 12536825 bf4bf9 vmlinux-CONFIG_MEMCG-before
8966750 1784992 1785856 12537598 bf4efe vmlinux-CONFIG_MEMCG-after
+773 text bytes
Performance tests run on v4.0-rc1-36-g4f671fe2f952. Lower is better for
all metrics, they're all wall clock or cycle counts. The read and write
fault benchmarks just measure fault time, they do not include I/O time.
* CONFIG_MEMCG not set:
baseline patched
kbuild 1m25.030000(+-0.088% 3 samples) 1m25.426667(+-0.120% 3 samples)
dd write 100 MiB 0.859211561 +-15.10% 0.874162885 +-15.03%
dd write 200 MiB 1.670653105 +-17.87% 1.669384764 +-11.99%
dd write 1000 MiB 8.434691190 +-14.15% 8.474733215 +-14.77%
read fault cycles 254.0(+-0.000% 10 samples) 253.0(+-0.000% 10 samples)
write fault cycles 2021.2(+-3.070% 10 samples) 1984.5(+-1.036% 10 samples)
* CONFIG_MEMCG=y root_memcg:
baseline patched
kbuild 1m25.716667(+-0.105% 3 samples) 1m25.686667(+-0.153% 3 samples)
dd write 100 MiB 0.855650830 +-14.90% 0.887557919 +-14.90%
dd write 200 MiB 1.688322953 +-12.72% 1.667682724 +-13.33%
dd write 1000 MiB 8.418601605 +-14.30% 8.673532299 +-15.00%
read fault cycles 266.0(+-0.000% 10 samples) 266.0(+-0.000% 10 samples)
write fault cycles 2051.7(+-1.349% 10 samples) 2049.6(+-1.686% 10 samples)
* CONFIG_MEMCG=y non-root_memcg:
baseline patched
kbuild 1m26.120000(+-0.273% 3 samples) 1m25.763333(+-0.127% 3 samples)
dd write 100 MiB 0.861723964 +-15.25% 0.818129350 +-14.82%
dd write 200 MiB 1.669887569 +-13.30% 1.698645885 +-13.27%
dd write 1000 MiB 8.383191730 +-14.65% 8.351742280 +-14.52%
read fault cycles 265.7(+-0.172% 10 samples) 267.0(+-0.000% 10 samples)
write fault cycles 2070.6(+-1.512% 10 samples) 2084.4(+-2.148% 10 samples)
As expected anon page faults are not affected by this patch.
tj: Updated to apply on top of the recent cancel_dirty_page() changes.
Signed-off-by: Sha Zhengju <handai.szj@gmail.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 23:13:16 +02:00
|
|
|
unsigned long flags;
|
|
|
|
|
2006-10-01 08:29:29 +02:00
|
|
|
if (page->mapping != mapping)
|
|
|
|
return 0;
|
|
|
|
|
2009-04-03 17:42:36 +02:00
|
|
|
if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL))
|
2006-10-01 08:29:29 +02:00
|
|
|
return 0;
|
|
|
|
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_lock_irqsave(&mapping->i_pages, flags);
|
2006-10-01 08:29:29 +02:00
|
|
|
if (PageDirty(page))
|
|
|
|
goto failed;
|
|
|
|
|
2009-04-03 17:42:36 +02:00
|
|
|
BUG_ON(page_has_private(page));
|
2016-03-15 22:57:22 +01:00
|
|
|
__delete_from_page_cache(page, NULL);
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_unlock_irqrestore(&mapping->i_pages, flags);
|
2010-12-01 19:35:19 +01:00
|
|
|
|
|
|
|
if (mapping->a_ops->freepage)
|
|
|
|
mapping->a_ops->freepage(page);
|
|
|
|
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
put_page(page); /* pagecache ref */
|
2006-10-01 08:29:29 +02:00
|
|
|
return 1;
|
|
|
|
failed:
|
2018-04-11 01:36:56 +02:00
|
|
|
xa_unlock_irqrestore(&mapping->i_pages, flags);
|
2006-10-01 08:29:29 +02:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2007-01-11 08:15:39 +01:00
|
|
|
static int do_launder_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
|
|
|
if (!PageDirty(page))
|
|
|
|
return 0;
|
|
|
|
if (page->mapping != mapping || mapping->a_ops->launder_page == NULL)
|
|
|
|
return 0;
|
|
|
|
return mapping->a_ops->launder_page(page);
|
|
|
|
}
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
/**
|
|
|
|
* invalidate_inode_pages2_range - remove range of pages from an address_space
|
2005-05-01 17:59:26 +02:00
|
|
|
* @mapping: the address_space
|
2005-04-17 00:20:36 +02:00
|
|
|
* @start: the page offset 'from' which to invalidate
|
|
|
|
* @end: the page offset 'to' which to invalidate (inclusive)
|
|
|
|
*
|
|
|
|
* Any pages which are found to be mapped into pagetables are unmapped prior to
|
|
|
|
* invalidation.
|
|
|
|
*
|
2008-09-02 23:35:40 +02:00
|
|
|
* Returns -EBUSY if any pages could not be invalidated.
|
2005-04-17 00:20:36 +02:00
|
|
|
*/
|
|
|
|
int invalidate_inode_pages2_range(struct address_space *mapping,
|
|
|
|
pgoff_t start, pgoff_t end)
|
|
|
|
{
|
2014-04-03 23:47:46 +02:00
|
|
|
pgoff_t indices[PAGEVEC_SIZE];
|
2005-04-17 00:20:36 +02:00
|
|
|
struct pagevec pvec;
|
2011-07-26 02:12:25 +02:00
|
|
|
pgoff_t index;
|
2005-04-17 00:20:36 +02:00
|
|
|
int i;
|
|
|
|
int ret = 0;
|
2008-04-28 11:12:08 +02:00
|
|
|
int ret2 = 0;
|
2005-04-17 00:20:36 +02:00
|
|
|
int did_range_unmap = 0;
|
|
|
|
|
2017-05-03 23:56:06 +02:00
|
|
|
if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
|
2017-05-03 23:56:09 +02:00
|
|
|
goto out;
|
2017-05-03 23:56:06 +02:00
|
|
|
|
2017-11-16 02:37:52 +01:00
|
|
|
pagevec_init(&pvec);
|
2011-07-26 02:12:25 +02:00
|
|
|
index = start;
|
2014-04-03 23:47:46 +02:00
|
|
|
while (index <= end && pagevec_lookup_entries(&pvec, mapping, index,
|
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1,
|
|
|
|
indices)) {
|
2007-03-01 05:13:55 +01:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
2005-04-17 00:20:36 +02:00
|
|
|
struct page *page = pvec.pages[i];
|
2011-07-26 02:12:25 +02:00
|
|
|
|
|
|
|
/* We rely upon deletion not changing page->index */
|
2014-04-03 23:47:46 +02:00
|
|
|
index = indices[i];
|
2011-07-26 02:12:25 +02:00
|
|
|
if (index > end)
|
|
|
|
break;
|
2005-04-17 00:20:36 +02:00
|
|
|
|
2017-11-03 18:30:42 +01:00
|
|
|
if (xa_is_value(page)) {
|
2016-08-10 17:22:44 +02:00
|
|
|
if (!invalidate_exceptional_entry2(mapping,
|
|
|
|
index, page))
|
|
|
|
ret = -EBUSY;
|
2014-04-03 23:47:46 +02:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
lock_page(page);
|
2016-12-01 00:54:19 +01:00
|
|
|
WARN_ON(page_to_index(page) != index);
|
2005-04-17 00:20:36 +02:00
|
|
|
if (page->mapping != mapping) {
|
|
|
|
unlock_page(page);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
wait_on_page_writeback(page);
|
mm: fix fault vs invalidate race for linear mappings
Fix the race between invalidate_inode_pages and do_no_page.
Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.
The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache. Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.
The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.
Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).
Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size. do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size). The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data. Valid mappings to the same
place will see a different page.
Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit. He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight. However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit. Scalability is not an issue.
This patch implements this latter approach. ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so). do_no_page only unlocks the page after setting up the mapping
completely. invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).
This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:46:57 +02:00
|
|
|
if (page_mapped(page)) {
|
2005-04-17 00:20:36 +02:00
|
|
|
if (!did_range_unmap) {
|
|
|
|
/*
|
|
|
|
* Zap the rest of the file in one hit.
|
|
|
|
*/
|
2018-02-01 01:17:36 +01:00
|
|
|
unmap_mapping_pages(mapping, index,
|
|
|
|
(1 + end - index), false);
|
2005-04-17 00:20:36 +02:00
|
|
|
did_range_unmap = 1;
|
|
|
|
} else {
|
|
|
|
/*
|
|
|
|
* Just zap this page
|
|
|
|
*/
|
2018-02-01 01:17:36 +01:00
|
|
|
unmap_mapping_pages(mapping, index,
|
|
|
|
1, false);
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
|
|
|
}
|
mm: fix fault vs invalidate race for linear mappings
Fix the race between invalidate_inode_pages and do_no_page.
Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.
The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache. Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.
The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.
Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).
Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size. do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size). The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data. Valid mappings to the same
place will see a different page.
Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit. He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight. However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit. Scalability is not an issue.
This patch implements this latter approach. ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so). do_no_page only unlocks the page after setting up the mapping
completely. invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).
This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:46:57 +02:00
|
|
|
BUG_ON(page_mapped(page));
|
2008-04-28 11:12:08 +02:00
|
|
|
ret2 = do_launder_page(mapping, page);
|
|
|
|
if (ret2 == 0) {
|
|
|
|
if (!invalidate_complete_page2(mapping, page))
|
2008-09-02 23:35:40 +02:00
|
|
|
ret2 = -EBUSY;
|
2008-04-28 11:12:08 +02:00
|
|
|
}
|
|
|
|
if (ret2 < 0)
|
|
|
|
ret = ret2;
|
2005-04-17 00:20:36 +02:00
|
|
|
unlock_page(page);
|
|
|
|
}
|
2014-04-03 23:47:46 +02:00
|
|
|
pagevec_remove_exceptionals(&pvec);
|
2005-04-17 00:20:36 +02:00
|
|
|
pagevec_release(&pvec);
|
|
|
|
cond_resched();
|
2011-07-26 02:12:25 +02:00
|
|
|
index++;
|
2005-04-17 00:20:36 +02:00
|
|
|
}
|
2017-05-13 00:46:50 +02:00
|
|
|
/*
|
2017-11-26 04:52:46 +01:00
|
|
|
* For DAX we invalidate page tables after invalidating page cache. We
|
2017-05-13 00:46:50 +02:00
|
|
|
* could invalidate page tables while invalidating each entry however
|
|
|
|
* that would be expensive. And doing range unmapping before doesn't
|
2017-11-26 04:52:46 +01:00
|
|
|
* work as we have no cheap way to find whether page cache entry didn't
|
2017-05-13 00:46:50 +02:00
|
|
|
* get remapped later.
|
|
|
|
*/
|
|
|
|
if (dax_mapping(mapping)) {
|
2018-02-01 01:17:36 +01:00
|
|
|
unmap_mapping_pages(mapping, start, end - start + 1, false);
|
2017-05-13 00:46:50 +02:00
|
|
|
}
|
2017-05-03 23:56:09 +02:00
|
|
|
out:
|
2011-09-21 17:56:28 +02:00
|
|
|
cleancache_invalidate_inode(mapping);
|
2005-04-17 00:20:36 +02:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* invalidate_inode_pages2 - remove all pages from an address_space
|
2005-05-01 17:59:26 +02:00
|
|
|
* @mapping: the address_space
|
2005-04-17 00:20:36 +02:00
|
|
|
*
|
|
|
|
* Any pages which are found to be mapped into pagetables are unmapped prior to
|
|
|
|
* invalidation.
|
|
|
|
*
|
2009-10-19 08:48:13 +02:00
|
|
|
* Returns -EBUSY if any pages could not be invalidated.
|
2005-04-17 00:20:36 +02:00
|
|
|
*/
|
|
|
|
int invalidate_inode_pages2(struct address_space *mapping)
|
|
|
|
{
|
|
|
|
return invalidate_inode_pages2_range(mapping, 0, -1);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
|
2009-08-20 18:35:05 +02:00
|
|
|
|
|
|
|
/**
|
|
|
|
* truncate_pagecache - unmap and remove pagecache that has been truncated
|
|
|
|
* @inode: inode
|
2011-07-26 02:12:24 +02:00
|
|
|
* @newsize: new file size
|
2009-08-20 18:35:05 +02:00
|
|
|
*
|
|
|
|
* inode's new i_size must already be written before truncate_pagecache
|
|
|
|
* is called.
|
|
|
|
*
|
|
|
|
* This function should typically be called before the filesystem
|
|
|
|
* releases resources associated with the freed range (eg. deallocates
|
|
|
|
* blocks). This way, pagecache will always stay logically coherent
|
|
|
|
* with on-disk format, and the filesystem would not have to deal with
|
|
|
|
* situations such as writepage being called for a page that has already
|
|
|
|
* had its underlying blocks deallocated.
|
|
|
|
*/
|
2013-09-13 00:13:56 +02:00
|
|
|
void truncate_pagecache(struct inode *inode, loff_t newsize)
|
2009-08-20 18:35:05 +02:00
|
|
|
{
|
2010-01-13 13:14:09 +01:00
|
|
|
struct address_space *mapping = inode->i_mapping;
|
2011-07-26 02:12:24 +02:00
|
|
|
loff_t holebegin = round_up(newsize, PAGE_SIZE);
|
2010-01-13 13:14:09 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* unmap_mapping_range is called twice, first simply for
|
|
|
|
* efficiency so that truncate_inode_pages does fewer
|
|
|
|
* single-page unmaps. However after this first call, and
|
|
|
|
* before truncate_inode_pages finishes, it is possible for
|
|
|
|
* private pages to be COWed, which remain after
|
|
|
|
* truncate_inode_pages finishes, hence the second
|
|
|
|
* unmap_mapping_range call must be made for correctness.
|
|
|
|
*/
|
2011-07-26 02:12:24 +02:00
|
|
|
unmap_mapping_range(mapping, holebegin, 0, 1);
|
|
|
|
truncate_inode_pages(mapping, newsize);
|
|
|
|
unmap_mapping_range(mapping, holebegin, 0, 1);
|
2009-08-20 18:35:05 +02:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(truncate_pagecache);
|
|
|
|
|
2010-06-04 11:30:04 +02:00
|
|
|
/**
|
|
|
|
* truncate_setsize - update inode and pagecache for a new file size
|
|
|
|
* @inode: inode
|
|
|
|
* @newsize: new file size
|
|
|
|
*
|
2011-01-20 23:44:26 +01:00
|
|
|
* truncate_setsize updates i_size and performs pagecache truncation (if
|
|
|
|
* necessary) to @newsize. It will be typically be called from the filesystem's
|
|
|
|
* setattr function when ATTR_SIZE is passed in.
|
2010-06-04 11:30:04 +02:00
|
|
|
*
|
2014-11-06 22:29:25 +01:00
|
|
|
* Must be called with a lock serializing truncates and writes (generally
|
|
|
|
* i_mutex but e.g. xfs uses a different lock) and before all filesystem
|
|
|
|
* specific block truncation has been performed.
|
2010-06-04 11:30:04 +02:00
|
|
|
*/
|
|
|
|
void truncate_setsize(struct inode *inode, loff_t newsize)
|
|
|
|
{
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
loff_t oldsize = inode->i_size;
|
|
|
|
|
2010-06-04 11:30:04 +02:00
|
|
|
i_size_write(inode, newsize);
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
if (newsize > oldsize)
|
|
|
|
pagecache_isize_extended(inode, oldsize, newsize);
|
2013-09-13 00:13:56 +02:00
|
|
|
truncate_pagecache(inode, newsize);
|
2010-06-04 11:30:04 +02:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(truncate_setsize);
|
|
|
|
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
/**
|
|
|
|
* pagecache_isize_extended - update pagecache after extension of i_size
|
|
|
|
* @inode: inode for which i_size was extended
|
|
|
|
* @from: original inode size
|
|
|
|
* @to: new inode size
|
|
|
|
*
|
|
|
|
* Handle extension of inode size either caused by extending truncate or by
|
|
|
|
* write starting after current i_size. We mark the page straddling current
|
|
|
|
* i_size RO so that page_mkwrite() is called on the nearest write access to
|
|
|
|
* the page. This way filesystem can be sure that page_mkwrite() is called on
|
|
|
|
* the page before user writes to the page via mmap after the i_size has been
|
|
|
|
* changed.
|
|
|
|
*
|
|
|
|
* The function must be called after i_size is updated so that page fault
|
|
|
|
* coming after we unlock the page will already see the new i_size.
|
|
|
|
* The function must be called while we still hold i_mutex - this not only
|
|
|
|
* makes sure i_size is stable but also that userspace cannot observe new
|
|
|
|
* i_size value before we are prepared to store mmap writes at new inode size.
|
|
|
|
*/
|
|
|
|
void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
|
|
|
|
{
|
2017-02-27 23:28:32 +01:00
|
|
|
int bsize = i_blocksize(inode);
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
loff_t rounded_from;
|
|
|
|
struct page *page;
|
|
|
|
pgoff_t index;
|
|
|
|
|
|
|
|
WARN_ON(to > inode->i_size);
|
|
|
|
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
if (from >= to || bsize == PAGE_SIZE)
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
return;
|
|
|
|
/* Page straddling @from will not have any hole block created? */
|
|
|
|
rounded_from = round_up(from, bsize);
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
if (to <= rounded_from || !(rounded_from & (PAGE_SIZE - 1)))
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
return;
|
|
|
|
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
index = from >> PAGE_SHIFT;
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
page = find_lock_page(inode->i_mapping, index);
|
|
|
|
/* Page not cached? Nothing to do */
|
|
|
|
if (!page)
|
|
|
|
return;
|
|
|
|
/*
|
|
|
|
* See clear_page_dirty_for_io() for details why set_page_dirty()
|
|
|
|
* is needed.
|
|
|
|
*/
|
|
|
|
if (page_mkclean(page))
|
|
|
|
set_page_dirty(page);
|
|
|
|
unlock_page(page);
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 14:29:47 +02:00
|
|
|
put_page(page);
|
vfs: fix data corruption when blocksize < pagesize for mmaped data
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
2014-10-02 03:49:18 +02:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(pagecache_isize_extended);
|
|
|
|
|
2012-03-28 23:42:40 +02:00
|
|
|
/**
|
|
|
|
* truncate_pagecache_range - unmap and remove pagecache that is hole-punched
|
|
|
|
* @inode: inode
|
|
|
|
* @lstart: offset of beginning of hole
|
|
|
|
* @lend: offset of last byte of hole
|
|
|
|
*
|
|
|
|
* This function should typically be called before the filesystem
|
|
|
|
* releases resources associated with the freed range (eg. deallocates
|
|
|
|
* blocks). This way, pagecache will always stay logically coherent
|
|
|
|
* with on-disk format, and the filesystem would not have to deal with
|
|
|
|
* situations such as writepage being called for a page that has already
|
|
|
|
* had its underlying blocks deallocated.
|
|
|
|
*/
|
|
|
|
void truncate_pagecache_range(struct inode *inode, loff_t lstart, loff_t lend)
|
|
|
|
{
|
|
|
|
struct address_space *mapping = inode->i_mapping;
|
|
|
|
loff_t unmap_start = round_up(lstart, PAGE_SIZE);
|
|
|
|
loff_t unmap_end = round_down(1 + lend, PAGE_SIZE) - 1;
|
|
|
|
/*
|
|
|
|
* This rounding is currently just for example: unmap_mapping_range
|
|
|
|
* expands its hole outwards, whereas we want it to contract the hole
|
|
|
|
* inwards. However, existing callers of truncate_pagecache_range are
|
2013-05-28 05:32:35 +02:00
|
|
|
* doing their own page rounding first. Note that unmap_mapping_range
|
|
|
|
* allows holelen 0 for all, and we allow lend -1 for end of file.
|
2012-03-28 23:42:40 +02:00
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Unlike in truncate_pagecache, unmap_mapping_range is called only
|
|
|
|
* once (before truncating pagecache), and without "even_cows" flag:
|
|
|
|
* hole-punching should not remove private COWed pages from the hole.
|
|
|
|
*/
|
|
|
|
if ((u64)unmap_end > (u64)unmap_start)
|
|
|
|
unmap_mapping_range(mapping, unmap_start,
|
|
|
|
1 + unmap_end - unmap_start, 0);
|
|
|
|
truncate_inode_pages_range(mapping, lstart, lend);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(truncate_pagecache_range);
|