commit 2457aec637 upstream.
aops->write_begin may allocate a new page and make it visible only to have
mark_page_accessed called almost immediately after. Once the page is
visible the atomic operations are necessary which is noticable overhead
when writing to an in-memory filesystem like tmpfs but should also be
noticable with fast storage. The objective of the patch is to initialse
the accessed information with non-atomic operations before the page is
visible.
The bulk of filesystems directly or indirectly use
grab_cache_page_write_begin or find_or_create_page for the initial
allocation of a page cache page. This patch adds an init_page_accessed()
helper which behaves like the first call to mark_page_accessed() but may
called before the page is visible and can be done non-atomically.
The primary APIs of concern in this care are the following and are used
by most filesystems.
find_get_page
find_lock_page
find_or_create_page
grab_cache_page_nowait
grab_cache_page_write_begin
All of them are very similar in detail to the patch creates a core helper
pagecache_get_page() which takes a flags parameter that affects its
behavior such as whether the page should be marked accessed or not. Then
old API is preserved but is basically a thin wrapper around this core
function.
Each of the filesystems are then updated to avoid calling
mark_page_accessed when it is known that the VM interfaces have already
done the job. There is a slight snag in that the timing of the
mark_page_accessed() has now changed so in rare cases it's possible a page
gets to the end of the LRU as PageReferenced where as previously it might
have been repromoted. This is expected to be rare but it's worth the
filesystem people thinking about it in case they see a problem with the
timing change. It is also the case that some filesystems may be marking
pages accessed that previously did not but it makes sense that filesystems
have consistent behaviour in this regard.
The test case used to evaulate this is a simple dd of a large file done
multiple times with the file deleted on each iterations. The size of the
file is 1/10th physical memory to avoid dirty page balancing. In the
async case it will be possible that the workload completes without even
hitting the disk and will have variable results but highlight the impact
of mark_page_accessed for async IO. The sync results are expected to be
more stable. The exception is tmpfs where the normal case is for the "IO"
to not hit the disk.
The test machine was single socket and UMA to avoid any scheduling or NUMA
artifacts. Throughput and wall times are presented for sync IO, only wall
times are shown for async as the granularity reported by dd and the
variability is unsuitable for comparison. As async results were variable
do to writback timings, I'm only reporting the maximum figures. The sync
results were stable enough to make the mean and stddev uninteresting.
The performance results are reported based on a run with no profiling.
Profile data is based on a separate run with oprofile running.
async dd
3.15.0-rc3 3.15.0-rc3
vanilla accessed-v2
ext3 Max elapsed 13.9900 ( 0.00%) 11.5900 ( 17.16%)
tmpfs Max elapsed 0.5100 ( 0.00%) 0.4900 ( 3.92%)
btrfs Max elapsed 12.8100 ( 0.00%) 12.7800 ( 0.23%)
ext4 Max elapsed 18.6000 ( 0.00%) 13.3400 ( 28.28%)
xfs Max elapsed 12.5600 ( 0.00%) 2.0900 ( 83.36%)
The XFS figure is a bit strange as it managed to avoid a worst case by
sheer luck but the average figures looked reasonable.
samples percentage
ext3 86107 0.9783 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
ext3 23833 0.2710 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext3 5036 0.0573 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
ext4 64566 0.8961 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
ext4 5322 0.0713 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext4 2869 0.0384 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs 62126 1.7675 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
xfs 1904 0.0554 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs 103 0.0030 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
btrfs 10655 0.1338 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
btrfs 2020 0.0273 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
btrfs 587 0.0079 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
tmpfs 59562 3.2628 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
tmpfs 1210 0.0696 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
tmpfs 94 0.0054 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
[akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e7470ee89f upstream.
Discarding buffers uses a bunch of atomic operations when discarding
buffers because ...... I can't think of a reason. Use a cmpxchg loop to
clear all the necessary flags. In most (all?) cases this will be a single
atomic operations.
[akpm@linux-foundation.org: move BUFFER_FLAGS_DISCARD into the .c file]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b745bc85f2 upstream.
cold is a bool, make it one. Make the likely case the "if" part of the
block instead of the else as according to the optimisation manual this is
preferred.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 378ff1a53b upstream.
It really needs to check that src is non-directory *and* use
{un,}lock_two_nodirectories(). As it is, it's trivial to cause
double-lock (ioctl(fd, CIFS_IOC_COPYCHUNK_FILE, fd)) and if the
last argument is an fd of directory, we are asking for trouble
by violating the locking order - all directories go before all
non-directories. If the last argument is an fd of parent
directory, it has 50% odds of locking child before parent,
which will cause AB-BA deadlock if we race with unlink().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6424babfd6 upstream.
During file system stress testing on 3.10 and 3.12 based kernels, the
umount command occasionally hung in fsnotify_unmount_inodes in the
section of code:
spin_lock(&inode->i_lock);
if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
spin_unlock(&inode->i_lock);
continue;
}
As this section of code holds the global inode_sb_list_lock, eventually
the system hangs trying to acquire the lock.
Multiple crash dumps showed:
The inode->i_state == 0x60 and i_count == 0 and i_sb_list would point
back at itself. As this is not the value of list upon entry to the
function, the kernel never exits the loop.
To help narrow down problem, the call to list_del_init in
inode_sb_list_del was changed to list_del. This poisons the pointers in
the i_sb_list and causes a kernel to panic if it transverse a freed
inode.
Subsequent stress testing paniced in fsnotify_unmount_inodes at the
bottom of the list_for_each_entry_safe loop showing next_i had become
free.
We believe the root cause of the problem is that next_i is being freed
during the window of time that the list_for_each_entry_safe loop
temporarily releases inode_sb_list_lock to call fsnotify and
fsnotify_inode_delete.
The code in fsnotify_unmount_inodes attempts to prevent the freeing of
inode and next_i by calling __iget. However, the code doesn't do the
__iget call on next_i
if i_count == 0 or
if i_state & (I_FREEING | I_WILL_FREE)
The patch addresses this issue by advancing next_i in the above two cases
until we either find a next_i which we can __iget or we reach the end of
the list. This makes the handling of next_i more closely match the
handling of the variable "inode."
The time to reproduce the hang is highly variable (from hours to days.) We
ran the stress test on a 3.10 kernel with the proposed patch for a week
without failure.
During list_for_each_entry_safe, next_i is becoming free causing
the loop to never terminate. Advance next_i in those cases where
__iget is not done.
Signed-off-by: Jerry Hoemann <jerry.hoemann@hp.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Ken Helias <kenhelias@firemail.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 06bed7d18c upstream.
This commit fixes a race whereby nlmclnt_init() first starts the lockd
daemon, and then calls nlm_bind_host() with the expectation that
nlmsvc_timeout has already been initialised. Unfortunately, there is no
no synchronisation between lockd() and lockd_up() to guarantee that this
is the case.
Fix is to move the initialisation of nlmsvc_timeout into lockd_create_svc
Fixes: 9a1b6bf818 ("LOCKD: Don't call utsname()->nodename...")
Cc: Bruce Fields <bfields@fieldses.org>
Cc: stable@vger.kernel.org # 3.10.x
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1fc0703af3 upstream.
Currently, our trunking code will check for session trunking, but will
fail to detect client id trunking. This is a problem, because it means
that the client will fail to recognise that the two connections represent
shared state, even if they do not permit a shared session.
By removing the check for the server minor id, and only checking the
major id, we will end up doing the right thing in both cases: we close
down the new nfs_client and fall back to using the existing one.
Fixes: 05f4c350ee ("NFS: Discover NFSv4 server trunking when mounting")
Cc: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c291ee6221 upstream.
Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.
CPU0 CPU1
show_interrupts()
desc = irq_to_desc(X);
free_desc(desc)
remove_from_radix_tree();
kfree(desc);
raw_spinlock_irq(&desc->lock);
/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.
The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.
For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.
Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.
Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.
Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.
Fixes: 1f5a5b87f7 "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6f8960541b upstream.
Commit 1d52c78afb (Btrfs: try not to ENOSPC on log replay) added a
check to skip delayed inode updates during log replay because it
confuses the enospc code. But the delayed processing will end up
ignoring delayed refs from log replay because the inode itself wasn't
put through the delayed code.
This can end up triggering a warning at commit time:
WARNING: CPU: 2 PID: 778 at fs/btrfs/delayed-inode.c:1410 btrfs_assert_delayed_root_empty+0x32/0x34()
Which is repeated for each commit because we never process the delayed
inode ref update.
The fix used here is to change btrfs_delayed_delete_inode_ref to return
an error if we're currently in log replay. The caller will do the ref
deletion immediately and everything will work properly.
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 705304a863 upstream.
Same story as in commit 41080b5a24 ("nfsd race fixes: ext2") (similar
ext2 fix) except that nilfs2 needs to use insert_inode_locked4() instead
of insert_inode_locked() and a bug of a check for dead inodes needs to
be fixed.
If nilfs_iget() is called from nfsd after nilfs_new_inode() calls
insert_inode_locked4(), nilfs_iget() will wait for unlock_new_inode() at
the end of nilfs_mkdir()/nilfs_create()/etc to unlock the inode.
If nilfs_iget() is called before nilfs_new_inode() calls
insert_inode_locked4(), it will create an in-core inode and read its
data from the on-disk inode. But, nilfs_iget() will find i_nlink equals
zero and fail at nilfs_read_inode_common(), which will lead it to call
iget_failed() and cleanly fail.
However, this sanity check doesn't work as expected for reused on-disk
inodes because they leave a non-zero value in i_mode field and it
hinders the test of i_nlink. This patch also fixes the issue by
removing the test on i_mode that nilfs2 doesn't need.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00bd8edb86 upstream.
send_mds_reconnect() may call discard_cap_releases() after all
release messages have been dropped by cleanup_cap_releases()
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Cc: Markus Blank-Burian <burian@muenster.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 021b77bee2 upstream.
Probably this code was syncing a lot more often then intended because
the do_sync variable wasn't set to zero.
Fixes: c62988ec09 ('ceph: avoid meaningless calling ceph_caps_revoking if sync_mode == WB_SYNC_ALL.')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5a64e56976 upstream.
Fix a bug where nfsd4_encode_components_esc() includes the esc_end char as
an additional string encoding.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: e7a0444aef "nfsd: add IPv6 addr escaping to fs_location hosts"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef17af2a81 upstream.
Bugs similar to the one in acbbe6fbb2 (kcmp: fix standard comparison
bug) are in rich supply.
In this variant, the problem is that struct xdr_netobj::len has type
unsigned int, so the expression o1->len - o2->len _also_ has type
unsigned int; it has completely well-defined semantics, and the result
is some non-negative integer, which is always representable in a long
long. But this means that if the conditional triggers, we are
guaranteed to return a positive value from compare_blob.
In this case it could be fixed by
- res = o1->len - o2->len;
+ res = (long long)o1->len - (long long)o2->len;
but I'd rather eliminate the usually broken 'return a - b;' idiom.
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9c6ac78eb3 upstream.
After invoking ->dirty_inode(), __mark_inode_dirty() does smp_mb() and
tests inode->i_state locklessly to see whether it already has all the
necessary I_DIRTY bits set. The comment above the barrier doesn't
contain any useful information - memory barriers can't ensure "changes
are seen by all cpus" by itself.
And it sure enough was broken. Please consider the following
scenario.
CPU 0 CPU 1
-------------------------------------------------------------------------------
enters __writeback_single_inode()
grabs inode->i_lock
tests PAGECACHE_TAG_DIRTY which is clear
enters __set_page_dirty()
grabs mapping->tree_lock
sets PAGECACHE_TAG_DIRTY
releases mapping->tree_lock
leaves __set_page_dirty()
enters __mark_inode_dirty()
smp_mb()
sees I_DIRTY_PAGES set
leaves __mark_inode_dirty()
clears I_DIRTY_PAGES
releases inode->i_lock
Now @inode has dirty pages w/ I_DIRTY_PAGES clear. This doesn't seem
to lead to an immediately critical problem because requeue_inode()
later checks PAGECACHE_TAG_DIRTY instead of I_DIRTY_PAGES when
deciding whether the inode needs to be requeued for IO and there are
enough unintentional memory barriers inbetween, so while the inode
ends up with inconsistent I_DIRTY_PAGES flag, it doesn't fall off the
IO list.
The lack of explicit barrier may also theoretically affect the other
I_DIRTY bits which deal with metadata dirtiness. There is no
guarantee that a strong enough barrier exists between
I_DIRTY_[DATA]SYNC clearing and write_inode() writing out the dirtied
inode. Filesystem inode writeout path likely has enough stuff which
can behave as full barrier but it's theoretically possible that the
writeout may not see all the updates from ->dirty_inode().
Fix it by adding an explicit smp_mb() after I_DIRTY clearing. Note
that I_DIRTY_PAGES needs a special treatment as it always needs to be
cleared to be interlocked with the lockless test on
__mark_inode_dirty() side. It's cleared unconditionally and
reinstated after smp_mb() if the mapping still has dirty pages.
Also add comments explaining how and why the barriers are paired.
Lightly tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 027bc8b082 upstream.
On some ARMs the memory can be mapped pgprot_noncached() and still
be working for atomic operations. As pointed out by Colin Cross
<ccross@android.com>, in some cases you do want to use
pgprot_noncached() if the SoC supports it to see a debug printk
just before a write hanging the system.
On ARMs, the atomic operations on strongly ordered memory are
implementation defined. So let's provide an optional kernel parameter
for configuring pgprot_noncached(), and use pgprot_writecombine() by
default.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robherring2@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7ae9cb8193 upstream.
Currently trying to use pstore on at least ARMs can hang as we're
mapping the peristent RAM with pgprot_noncached().
On ARMs, pgprot_noncached() will actually make the memory strongly
ordered, and as the atomic operations pstore uses are implementation
defined for strongly ordered memory, they may not work. So basically
atomic operations have undefined behavior on ARM for device or strongly
ordered memory types.
Let's fix the issue by using write-combine variants for mappings. This
corresponds to normal, non-cacheable memory on ARM. For many other
architectures, this change does not change the mapping type as by
default we have:
#define pgprot_writecombine pgprot_noncached
The reason why pgprot_noncached() was originaly used for pstore
is because Colin Cross <ccross@android.com> had observed lost
debug prints right before a device hanging write operation on some
systems. For the platforms supporting pgprot_noncached(), we can
add a an optional configuration option to support that. But let's
get pstore working first before adding new features.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: linux-kernel@vger.kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
[tony@atomide.com: updated description]
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 53dc20b9a3 upstream.
In ocfs2_link(), the parent directory inode passed to function
ocfs2_lookup_ino_from_name() is wrong. Parameter dir is the parent of
new_dentry not old_dentry. We should get old_dir from old_dentry and
lookup old_dentry in old_dir in case another node remove the old dentry.
With this change, hard linking works again, when paths are relative with
at least one subdirectory. This is how the problem was reproducable:
# mkdir a
# mkdir b
# touch a/test
# ln a/test b/test
ln: failed to create hard link `b/test' => `a/test': No such file or directory
However when creating links in the same dir, it worked well.
Now the link gets created.
Fixes: 0e048316ff ("ocfs2: check existence of old dentry in ocfs2_link()")
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reported-by: Szabo Aron - UBIT <aron@ubit.hu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Tested-by: Aron Szabo <aron@ubit.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 136f49b917 upstream.
For buffer write, page lock will be got in write_begin and released in
write_end, in ocfs2_write_end_nolock(), before it unlock the page in
ocfs2_free_write_ctxt(), it calls ocfs2_run_deallocs(), this will ask
for the read lock of journal->j_trans_barrier. Holding page lock and
ask for journal->j_trans_barrier breaks the locking order.
This will cause a deadlock with journal commit threads, ocfs2cmt will
get write lock of journal->j_trans_barrier first, then it wakes up
kjournald2 to do the commit work, at last it waits until done. To
commit journal, kjournald2 needs flushing data first, it needs get the
cache page lock.
Since some ocfs2 cluster locks are holding by write process, this
deadlock may hung the whole cluster.
unlock pages before ocfs2_run_deallocs() can fix the locking order, also
put unlock before ocfs2_commit_trans() to make page lock is unlocked
before j_trans_barrier to preserve unlocking order.
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 678886bdc6 upstream.
When we abort a transaction we iterate over all the ranges marked as dirty
in fs_info->freed_extents[0] and fs_info->freed_extents[1], clear them
from those trees, add them back (unpin) to the free space caches and, if
the fs was mounted with "-o discard", perform a discard on those regions.
Also, after adding the regions to the free space caches, a fitrim ioctl call
can see those ranges in a block group's free space cache and perform a discard
on the ranges, so the same issue can happen without "-o discard" as well.
This causes corruption, affecting one or multiple btree nodes (in the worst
case leaving the fs unmountable) because some of those ranges (the ones in
the fs_info->pinned_extents tree) correspond to btree nodes/leafs that are
referred by the last committed super block - breaking the rule that anything
that was committed by a transaction is untouched until the next transaction
commits successfully.
I ran into this while running in a loop (for several hours) the fstest that
I recently submitted:
[PATCH] fstests: add btrfs test to stress chunk allocation/removal and fstrim
The corruption always happened when a transaction aborted and then fsck complained
like this:
_check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent
*** fsck.btrfs output ***
Check tree block failed, want=94945280, have=0
Check tree block failed, want=94945280, have=0
Check tree block failed, want=94945280, have=0
Check tree block failed, want=94945280, have=0
Check tree block failed, want=94945280, have=0
read block failed check_tree_block
Couldn't open file system
In this case 94945280 corresponded to the root of a tree.
Using frace what I observed was the following sequence of steps happened:
1) transaction N started, fs_info->pinned_extents pointed to
fs_info->freed_extents[0];
2) node/eb 94945280 is created;
3) eb is persisted to disk;
4) transaction N commit starts, fs_info->pinned_extents now points to
fs_info->freed_extents[1], and transaction N completes;
5) transaction N + 1 starts;
6) eb is COWed, and btrfs_free_tree_block() called for this eb;
7) eb range (94945280 to 94945280 + 16Kb) is added to
fs_info->pinned_extents (fs_info->freed_extents[1]);
8) Something goes wrong in transaction N + 1, like hitting ENOSPC
for example, and the transaction is aborted, turning the fs into
readonly mode. The stack trace I got for example:
[112065.253935] [<ffffffff8140c7b6>] dump_stack+0x4d/0x66
[112065.254271] [<ffffffff81042984>] warn_slowpath_common+0x7f/0x98
[112065.254567] [<ffffffffa0325990>] ? __btrfs_abort_transaction+0x50/0x10b [btrfs]
[112065.261674] [<ffffffff810429e5>] warn_slowpath_fmt+0x48/0x50
[112065.261922] [<ffffffffa032949e>] ? btrfs_free_path+0x26/0x29 [btrfs]
[112065.262211] [<ffffffffa0325990>] __btrfs_abort_transaction+0x50/0x10b [btrfs]
[112065.262545] [<ffffffffa036b1d6>] btrfs_remove_chunk+0x537/0x58b [btrfs]
[112065.262771] [<ffffffffa033840f>] btrfs_delete_unused_bgs+0x1de/0x21b [btrfs]
[112065.263105] [<ffffffffa0343106>] cleaner_kthread+0x100/0x12f [btrfs]
(...)
[112065.264493] ---[ end trace dd7903a975a31a08 ]---
[112065.264673] BTRFS: error (device sdc) in btrfs_remove_chunk:2625: errno=-28 No space left
[112065.264997] BTRFS info (device sdc): forced readonly
9) The clear kthread sees that the BTRFS_FS_STATE_ERROR bit is set in
fs_info->fs_state and calls btrfs_cleanup_transaction(), which in
turn calls btrfs_destroy_pinned_extent();
10) Then btrfs_destroy_pinned_extent() iterates over all the ranges
marked as dirty in fs_info->freed_extents[], and for each one
it calls discard, if the fs was mounted with "-o discard", and
adds the range to the free space cache of the respective block
group;
11) btrfs_trim_block_group(), invoked from the fitrim ioctl code path,
sees the free space entries and performs a discard;
12) After an umount and mount (or fsck), our eb's location on disk was full
of zeroes, and it should have been untouched, because it was marked as
dirty in the fs_info->pinned_extents tree, and therefore used by the
trees that the last committed superblock points to.
Fix this by not performing a discard and not adding the ranges to the free space
caches - it's useless from this point since the fs is now in readonly mode and
we won't write free space caches to disk anymore (otherwise we would leak space)
nor any new superblock. By not adding the ranges to the free space caches, it
prevents other code paths from allocating that space and write to it as well,
therefore being safer and simpler.
This isn't a new problem, as it's been present since 2011 (git commit
acce952b02).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a28046956c upstream.
We use the modified list to keep track of which extents have been modified so we
know which ones are candidates for logging at fsync() time. Newly modified
extents are added to the list at modification time, around the same time the
ordered extent is created. We do this so that we don't have to wait for ordered
extents to complete before we know what we need to log. The problem is when
something like this happens
log extent 0-4k on inode 1
copy csum for 0-4k from ordered extent into log
sync log
commit transaction
log some other extent on inode 1
ordered extent for 0-4k completes and adds itself onto modified list again
log changed extents
see ordered extent for 0-4k has already been logged
at this point we assume the csum has been copied
sync log
crash
On replay we will see the extent 0-4k in the log, drop the original 0-4k extent
which is the same one that we are replaying which also drops the csum, and then
we won't find the csum in the log for that bytenr. This of course causes us to
have errors about not having csums for certain ranges of our inode. So remove
the modified list manipulation in unpin_extent_cache, any modified extents
should have been added well before now, and we don't want them re-logged. This
fixes my test that I could reliably reproduce this problem with. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 942080643b upstream.
Dmitry Chernenkov used KASAN to discover that eCryptfs writes past the
end of the allocated buffer during encrypted filename decoding. This
fix corrects the issue by getting rid of the unnecessary 0 write when
the current bit offset is 2.
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Reported-by: Dmitry Chernenkov <dmitryc@google.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 332b122d39 upstream.
The ecryptfs_encrypted_view mount option greatly changes the
functionality of an eCryptfs mount. Instead of encrypting and decrypting
lower files, it provides a unified view of the encrypted files in the
lower filesystem. The presence of the ecryptfs_encrypted_view mount
option is intended to force a read-only mount and modifying files is not
supported when the feature is in use. See the following commit for more
information:
e77a56d [PATCH] eCryptfs: Encrypted passthrough
This patch forces the mount to be read-only when the
ecryptfs_encrypted_view mount option is specified by setting the
MS_RDONLY flag on the superblock. Additionally, this patch removes some
broken logic in ecryptfs_open() that attempted to prevent modifications
of files when the encrypted view feature was in use. The check in
ecryptfs_open() was not sufficient to prevent file modifications using
system calls that do not operate on a file descriptor.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Priya Bansal <p.bansal@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a1d47b2629 upstream.
UDF specification allows arbitrarily large symlinks. However we support
only symlinks at most one block large. Check the length of the symlink
so that we don't access memory beyond end of the symlink block.
Reported-by: Carl Henrik Lunde <chlunde@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a682e9c28c upstream.
If some error happens in NCP_IOC_SETROOT ioctl, the appropriate error
return value is then (in most cases) just overwritten before we return.
This can result in reporting success to userspace although error happened.
This bug was introduced by commit 2e54eb96e2 ("BKL: Remove BKL from
ncpfs"). Propagate the errors correctly.
Coverity id: 1226925.
Fixes: 2e54eb96e2 ("BKL: Remove BKL from ncpfs")
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9cc46516dd upstream.
- Expose the knob to user space through a proc file /proc/<pid>/setgroups
A value of "deny" means the setgroups system call is disabled in the
current processes user namespace and can not be enabled in the
future in this user namespace.
A value of "allow" means the segtoups system call is enabled.
- Descendant user namespaces inherit the value of setgroups from
their parents.
- A proc file is used (instead of a sysctl) as sysctls currently do
not allow checking the permissions at open time.
- Writing to the proc file is restricted to before the gid_map
for the user namespace is set.
This ensures that disabling setgroups at a user namespace
level will never remove the ability to call setgroups
from a process that already has that ability.
A process may opt in to the setgroups disable for itself by
creating, entering and configuring a user namespace or by calling
setns on an existing user namespace with setgroups disabled.
Processes without privileges already can not call setgroups so this
is a noop. Prodcess with privilege become processes without
privilege when entering a user namespace and as with any other path
to dropping privilege they would not have the ability to call
setgroups. So this remains within the bounds of what is possible
without a knob to disable setgroups permanently in a user namespace.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b2f5d4dc38 upstream.
Forced unmount affects not just the mount namespace but the underlying
superblock as well. Restrict forced unmount to the global root user
for now. Otherwise it becomes possible a user in a less privileged
mount namespace to force the shutdown of a superblock of a filesystem
in a more privileged mount namespace, allowing a DOS attack on root.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3e1866410f upstream.
Now that remount is properly enforcing the rule that you can't remove
nodev at least sandstorm.io is breaking when performing a remount.
It turns out that there is an easy intuitive solution implicitly
add nodev on remount when nodev was implicitly added on mount.
Tested-by: Cedric Bosdonnat <cbosdonnat@suse.com>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c297abfdf1 upstream.
While reviewing the code of umount_tree I realized that when we append
to a preexisting unmounted list we do not change pprev of the former
first item in the list.
Which means later in namespace_unlock hlist_del_init(&mnt->mnt_hash) on
the former first item of the list will stomp unmounted.first leaving
it set to some random mount point which we are likely to free soon.
This isn't likely to hit, but if it does I don't know how anyone could
track it down.
[ This happened because we don't have all the same operations for
hlist's as we do for normal doubly-linked lists. In particular,
list_splice() is easy on our standard doubly-linked lists, while
hlist_splice() doesn't exist and needs both start/end entries of the
hlist. And commit 38129a13e6 incorrectly open-coded that missing
hlist_splice().
We should think about making these kinds of "mindless" conversions
easier to get right by adding the missing hlist helpers - Linus ]
Fixes: 38129a13e6 switch mnt_hash to hlist
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4e2024624e upstream.
We didn't check length of rock ridge ER records before printing them.
Thus corrupted isofs image can cause us to access and print some memory
behind the buffer with obvious consequences.
Reported-and-tested-by: Carl Henrik Lunde <chlunde@ping.uio.no>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4bd5a980de upstream.
nfs4_layoutget_release() drops layout hdr refcnt. Grab the refcnt
early so that it is safe to call .release in case nfs4_alloc_pages
fails.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Fixes: a47970ff78 ("NFSv4.1: Hold reference to layout hdr in layoutget")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f54e18f1b8 upstream.
Rock Ridge extensions define so called Continuation Entries (CE) which
define where is further space with Rock Ridge data. Corrupted isofs
image can contain arbitrarily long chain of these, including a one
containing loop and thus causing kernel to end in an infinite loop when
traversing these entries.
Limit the traversal to 32 entries which should be more than enough space
to store all the Rock Ridge data.
Reported-by: P J P <ppandit@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 92a56555bd upstream.
If a SIGKILL is sent to a task waiting in __nfs_iocounter_wait,
it will busy-wait or soft lockup in its while loop.
nfs_wait_bit_killable won't sleep, and the loop won't exit on
the error return.
Stop the busy-wait by breaking out of the loop when
nfs_wait_bit_killable returns an error.
Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
[ kamal: backport to 3.13-stable: context ]
Cc: Moritz Mühlenhoff <muehlenhoff@univention.de>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8c3cac5e6a upstream.
A leftover lock on the list is surely a sign of a problem of some sort,
but it's not necessarily a reason to panic the box. Instead, just log a
warning with some info about the lock, and then delete it like we would
any other lock.
In the event that the filesystem declares a ->lock f_op, we may end up
leaking something, but that's generally preferable to an immediate
panic.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Markus Blank-Burian <burian@muenster.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1b19453d1c upstream.
Currently, the DRC cache pruner will stop scanning the list when it
hits an entry that is RC_INPROG. It's possible however for a call to
take a *very* long time. In that case, we don't want it to block other
entries from being pruned if they are expired or we need to trim the
cache to get back under the limit.
Fix the DRC cache pruner to just ignore RC_INPROG entries.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Cc: Joseph Salisbury <joseph.salisbury@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c6c15e1ed3 upstream.
The currect code for nfsd41_cb_get_slot() and nfsd4_cb_done() has no
locking in order to guarantee atomicity, and so allows for races of
the form.
Task 1 Task 2
====== ======
if (test_and_set_bit(0) != 0) {
clear_bit(0)
rpc_wake_up_next(queue)
rpc_sleep_on(queue)
return false;
}
This patch breaks the race condition by adding a retest of the bit
after the call to rpc_sleep_on().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6d0ba0432a upstream.
Even when security labels are disabled we support at least the same
attributes as v4.1.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 835f252c6d upstream.
https://bugzilla.kernel.org/show_bug.cgi?id=86831
Markus reported that when shutting down mysqld (with AIO support,
on a ext3 formatted Harddrive) leads to a negative number of dirty pages
(underrun to the counter). The negative number results in a drastic reduction
of the write performance because the page cache is not used, because the kernel
thinks it is still 2 ^ 32 dirty pages open.
Add a warn trace in __dec_zone_state will catch this easily:
static inline void __dec_zone_state(struct zone *zone, enum
zone_stat_item item)
{
atomic_long_dec(&zone->vm_stat[item]);
+ WARN_ON_ONCE(item == NR_FILE_DIRTY &&
atomic_long_read(&zone->vm_stat[item]) < 0);
atomic_long_dec(&vm_stat[item]);
}
[ 21.341632] ------------[ cut here ]------------
[ 21.346294] WARNING: CPU: 0 PID: 309 at include/linux/vmstat.h:242
cancel_dirty_page+0x164/0x224()
[ 21.355296] Modules linked in: wutbox_cp sata_mv
[ 21.359968] CPU: 0 PID: 309 Comm: kworker/0:1 Not tainted 3.14.21-WuT #80
[ 21.366793] Workqueue: events free_ioctx
[ 21.370760] [<c0016a64>] (unwind_backtrace) from [<c0012f88>]
(show_stack+0x20/0x24)
[ 21.378562] [<c0012f88>] (show_stack) from [<c03f8ccc>]
(dump_stack+0x24/0x28)
[ 21.385840] [<c03f8ccc>] (dump_stack) from [<c0023ae4>]
(warn_slowpath_common+0x84/0x9c)
[ 21.393976] [<c0023ae4>] (warn_slowpath_common) from [<c0023bb8>]
(warn_slowpath_null+0x2c/0x34)
[ 21.402800] [<c0023bb8>] (warn_slowpath_null) from [<c00c0688>]
(cancel_dirty_page+0x164/0x224)
[ 21.411524] [<c00c0688>] (cancel_dirty_page) from [<c00c080c>]
(truncate_inode_page+0x8c/0x158)
[ 21.420272] [<c00c080c>] (truncate_inode_page) from [<c00c0a94>]
(truncate_inode_pages_range+0x11c/0x53c)
[ 21.429890] [<c00c0a94>] (truncate_inode_pages_range) from
[<c00c0f6c>] (truncate_pagecache+0x88/0xac)
[ 21.439252] [<c00c0f6c>] (truncate_pagecache) from [<c00c0fec>]
(truncate_setsize+0x5c/0x74)
[ 21.447731] [<c00c0fec>] (truncate_setsize) from [<c013b3a8>]
(put_aio_ring_file.isra.14+0x34/0x90)
[ 21.456826] [<c013b3a8>] (put_aio_ring_file.isra.14) from
[<c013b424>] (aio_free_ring+0x20/0xcc)
[ 21.465660] [<c013b424>] (aio_free_ring) from [<c013b4f4>]
(free_ioctx+0x24/0x44)
[ 21.473190] [<c013b4f4>] (free_ioctx) from [<c003d8d8>]
(process_one_work+0x134/0x47c)
[ 21.481132] [<c003d8d8>] (process_one_work) from [<c003e988>]
(worker_thread+0x130/0x414)
[ 21.489350] [<c003e988>] (worker_thread) from [<c00448ac>]
(kthread+0xd4/0xec)
[ 21.496621] [<c00448ac>] (kthread) from [<c000ec18>]
(ret_from_fork+0x14/0x20)
[ 21.503884] ---[ end trace 79c4bf42c038c9a1 ]---
The cause is that we set the aio ring file pages as *DIRTY* via SetPageDirty
(bypasses the VFS dirty pages increment) when init, and aio fs uses
*default_backing_dev_info* as the backing dev, which does not disable
the dirty pages accounting capability.
So truncating aio ring file will contribute to accounting dirty pages (VFS
dirty pages decrement), then error occurs.
The original goal is keeping these pages in memory (can not be reclaimed
or swapped) in life-time via marking it dirty. But thinking more, we have
already pinned pages via elevating the page's refcount, which can already
achieve the goal, so the SetPageDirty seems unnecessary.
In order to fix the issue, using the __set_page_dirty_no_writeback instead
of the nop .set_page_dirty, and dropped the SetPageDirty (don't manually
set the dirty flags, don't disable set_page_dirty(), rely on default behaviour).
With the above change, the dirty pages accounting can work well. But as we
known, aio fs is an anonymous one, which should never cause any real write-back,
we can ignore the dirty pages (write back) accounting by disabling the dirty
pages (write back) accounting capability. So we introduce an aio private
backing dev info (disabled the ACCT_DIRTY/WRITEBACK/ACCT_WB capabilities) to
replace the default one.
Reported-by: Markus Königshaus <m.koenigshaus@wut.de>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d23da150a3 upstream.
We remove the call to grab_super_passive in call to super_cache_count.
This becomes a scalability bottleneck as multiple threads are trying to do
memory reclamation, e.g. when we are doing large amount of file read and
page cache is under pressure. The cached objects quickly got reclaimed
down to 0 and we are aborting the cache_scan() reclaim. But counting
creates a log jam acquiring the sb_lock.
We are holding the shrinker_rwsem which ensures the safety of call to
list_lru_count_node() and s_op->nr_cached_objects. The shrinker is
unregistered now before ->kill_sb() so the operation is safe when we are
doing unmount.
The impact will depend heavily on the machine and the workload but for a
small machine using postmark tuned to use 4xRAM size the results were
3.15.0-rc5 3.15.0-rc5
vanilla shrinker-v1r1
Ops/sec Transactions 21.00 ( 0.00%) 24.00 ( 14.29%)
Ops/sec FilesCreate 39.00 ( 0.00%) 44.00 ( 12.82%)
Ops/sec CreateTransact 10.00 ( 0.00%) 12.00 ( 20.00%)
Ops/sec FilesDeleted 6202.00 ( 0.00%) 6202.00 ( 0.00%)
Ops/sec DeleteTransact 11.00 ( 0.00%) 12.00 ( 9.09%)
Ops/sec DataRead/MB 25.97 ( 0.00%) 29.10 ( 12.05%)
Ops/sec DataWrite/MB 49.99 ( 0.00%) 56.02 ( 12.06%)
ffsb running in a configuration that is meant to simulate a mail server showed
3.15.0-rc5 3.15.0-rc5
vanilla shrinker-v1r1
Ops/sec readall 9402.63 ( 0.00%) 9567.97 ( 1.76%)
Ops/sec create 4695.45 ( 0.00%) 4735.00 ( 0.84%)
Ops/sec delete 173.72 ( 0.00%) 179.83 ( 3.52%)
Ops/sec Transactions 14271.80 ( 0.00%) 14482.81 ( 1.48%)
Ops/sec Read 37.00 ( 0.00%) 37.60 ( 1.62%)
Ops/sec Write 18.20 ( 0.00%) 18.30 ( 0.55%)
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 28f2cd4f6d upstream.
This series is aimed at regressions noticed during reclaim activity. The
first two patches are shrinker patches that were posted ages ago but never
merged for reasons that are unclear to me. I'm posting them again to see
if there was a reason they were dropped or if they just got lost. Dave?
Time? The last patch adjusts proportional reclaim. Yuanhan Liu, can you
retest the vm scalability test cases on a larger machine? Hugh, does this
work for you on the memcg test cases?
Based on ext4, I get the following results but unfortunately my larger
test machines are all unavailable so this is based on a relatively small
machine.
postmark
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
Ops/sec Transactions 21.00 ( 0.00%) 25.00 ( 19.05%)
Ops/sec FilesCreate 39.00 ( 0.00%) 45.00 ( 15.38%)
Ops/sec CreateTransact 10.00 ( 0.00%) 12.00 ( 20.00%)
Ops/sec FilesDeleted 6202.00 ( 0.00%) 6202.00 ( 0.00%)
Ops/sec DeleteTransact 11.00 ( 0.00%) 12.00 ( 9.09%)
Ops/sec DataRead/MB 25.97 ( 0.00%) 30.02 ( 15.59%)
Ops/sec DataWrite/MB 49.99 ( 0.00%) 57.78 ( 15.58%)
ffsb (mail server simulator)
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
Ops/sec readall 9402.63 ( 0.00%) 9805.74 ( 4.29%)
Ops/sec create 4695.45 ( 0.00%) 4781.39 ( 1.83%)
Ops/sec delete 173.72 ( 0.00%) 177.23 ( 2.02%)
Ops/sec Transactions 14271.80 ( 0.00%) 14764.37 ( 3.45%)
Ops/sec Read 37.00 ( 0.00%) 38.50 ( 4.05%)
Ops/sec Write 18.20 ( 0.00%) 18.50 ( 1.65%)
dd of a large file
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
WallTime DownloadTar 75.00 ( 0.00%) 61.00 ( 18.67%)
WallTime DD 423.00 ( 0.00%) 401.00 ( 5.20%)
WallTime Delete 2.00 ( 0.00%) 5.00 (-150.00%)
stutter (times mmap latency during large amounts of IO)
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
Unit >5ms Delays 80252.0000 ( 0.00%) 81523.0000 ( -1.58%)
Unit Mmap min 8.2118 ( 0.00%) 8.3206 ( -1.33%)
Unit Mmap mean 17.4614 ( 0.00%) 17.2868 ( 1.00%)
Unit Mmap stddev 24.9059 ( 0.00%) 34.6771 (-39.23%)
Unit Mmap max 2811.6433 ( 0.00%) 2645.1398 ( 5.92%)
Unit Mmap 90% 20.5098 ( 0.00%) 18.3105 ( 10.72%)
Unit Mmap 93% 22.9180 ( 0.00%) 20.1751 ( 11.97%)
Unit Mmap 95% 25.2114 ( 0.00%) 22.4988 ( 10.76%)
Unit Mmap 99% 46.1430 ( 0.00%) 43.5952 ( 5.52%)
Unit Ideal Tput 85.2623 ( 0.00%) 78.8906 ( 7.47%)
Unit Tput min 44.0666 ( 0.00%) 43.9609 ( 0.24%)
Unit Tput mean 45.5646 ( 0.00%) 45.2009 ( 0.80%)
Unit Tput stddev 0.9318 ( 0.00%) 1.1084 (-18.95%)
Unit Tput max 46.7375 ( 0.00%) 46.7539 ( -0.04%)
This patch (of 3):
We will like to unregister the sb shrinker before ->kill_sb(). This will
allow cached objects to be counted without call to grab_super_passive() to
update ref count on sb. We want to avoid locking during memory
reclamation especially when we are skipping the memory reclaim when we are
out of cached objects.
This is safe because grab_super_passive does a try-lock on the
sb->s_umount now, and so if we are in the unmount process, it won't ever
block. That means what used to be a deadlock and races we were avoiding
by using grab_super_passive() is now:
shrinker umount
down_read(shrinker_rwsem)
down_write(sb->s_umount)
shrinker_unregister
down_write(shrinker_rwsem)
<blocks>
grab_super_passive(sb)
down_read_trylock(sb->s_umount)
<fails>
<shrinker aborts>
....
<shrinkers finish running>
up_read(shrinker_rwsem)
<unblocks>
<removes shrinker>
up_write(shrinker_rwsem)
->kill_sb()
....
So it is safe to deregister the shrinker before ->kill_sb().
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67f9fd91f9 upstream.
This patch removes read_cache_page_async() which wasn't really needed
anywhere and simplifies the code around it a bit.
read_cache_page_async() is useful when we want to read a page into the
cache without waiting for it to complete. This happens when the
appropriate callback 'filler' doesn't complete its read operation and
releases the page lock immediately, and instead queues a different
completion routine to do that. This never actually happened anywhere in
the code.
read_cache_page_async() had 3 different callers:
- read_cache_page() which is the sync version, it would just wait for
the requested read to complete using wait_on_page_read().
- JFFS2 would call it from jffs2_gc_fetch_page(), but the filler
function it supplied doesn't do any async reads, and would complete
before the filler function returns - making it actually a sync read.
- CRAMFS would call it using the read_mapping_page_async() wrapper, with
a similar story to JFFS2 - the filler function doesn't do anything that
reminds async reads and would always complete before the filler function
returns.
To sum it up, the code in mm/filemap.c never took advantage of having
read_cache_page_async(). While there are filler callbacks that do async
reads (such as the block one), we always called it with the
read_cache_page().
This patch adds a mandatory wait for read to complete when adding a new
page to the cache, and removes read_cache_page_async() and its wrappers.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0cd6144aad upstream.
shmem mappings already contain exceptional entries where swap slot
information is remembered.
To be able to store eviction information for regular page cache, prepare
every site dealing with the radix trees directly to handle entries other
than pages.
The common lookup functions will filter out non-page entries and return
NULL for page cache holes, just as before. But provide a raw version of
the API which returns non-page entries as well, and switch shmem over to
use it.
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>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e7b563bb2a upstream.
The radix tree hole searching code is only used for page cache, for
example the readahead code trying to get a a picture of the area
surrounding a fault.
It sufficed to rely on the radix tree definition of holes, which is
"empty tree slot". But this is about to change, though, as shadow page
descriptors will be stored in the page cache after the actual pages get
evicted from memory.
Move the functions over to mm/filemap.c and make them native page cache
operations, where they can later be adapted to handle the new definition
of "page cache hole".
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Acked-by: Mel Gorman <mgorman@suse.de>
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: 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>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1b2ad41214 upstream.
Now that rgrps use the address space which is part of the super
block, we need to update gfs2_mapping2sbd() to take account of
that. The only way to do that easily is to use a different set
of address_space_operations for rgrps.
Reported-by: Abhi Das <adas@redhat.com>
Tested-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0c116cadd9 upstream.
This patch removes the assumption made previously, that we only need to
check the delegation stateid when it matches the stateid on a cached
open.
If we believe that we hold a delegation for this file, then we must assume
that its stateid may have been revoked or expired too. If we don't test it
then our state recovery process may end up caching open/lock state in a
situation where it should not.
We therefore rename the function nfs41_clear_delegation_stateid as
nfs41_check_delegation_stateid, and change it to always run through the
delegation stateid test and recovery process as outlined in RFC5661.
http://lkml.kernel.org/r/CAN-5tyHwG=Cn2Q9KsHWadewjpTTy_K26ee+UnSvHvG4192p-Xw@mail.gmail.com
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 869f9dfa4d upstream.
Any attempt to call nfs_remove_bad_delegation() while a delegation is being
returned is currently a no-op. This means that we can end up looping
forever in nfs_end_delegation_return() if something causes the delegation
to be revoked.
This patch adds a mechanism whereby the state recovery code can communicate
to the delegation return code that the delegation is no longer valid and
that it should not be used when reclaiming state.
It also changes the return value for nfs4_handle_delegation_recall_error()
to ensure that nfs_end_delegation_return() does not reattempt the lock
reclaim before state recovery is done.
http://lkml.kernel.org/r/CAN-5tyHwG=Cn2Q9KsHWadewjpTTy_K26ee+UnSvHvG4192p-Xw@mail.gmail.com
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 16caf5b610 upstream.
Variable 'err' needn't be initialized when nfs_getattr() uses it to
check whether it should call generic_fillattr() or not. That can result
in spurious error returns. Initialize 'err' properly.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4dfd4f7af0 upstream.
NFSv4.0 does not have TEST_STATEID/FREE_STATEID functionality, so
unlike NFSv4.1, the recovery procedure when stateids have expired or
have been revoked requires us to just forget the delegation.
http://lkml.kernel.org/r/CAN-5tyHwG=Cn2Q9KsHWadewjpTTy_K26ee+UnSvHvG4192p-Xw@mail.gmail.com
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mel Gorman
Al Viro
Jerry Hoemann
Trond Myklebust
Thomas Gleixner
Chris Mason
Ryusuke Konishi
Yan, Zheng
Dan Carpenter
Benjamin Coddington
Rasmus Villemoes
Tejun Heo
Tony Lindgren
Rob Herring
Xue jiufei
Junxiao Bi
Filipe Manana
Josef Bacik
Michael Halcrow
Tyler Hicks
Jan Kara
Eric W. Biederman
Peng Tao
David Jeffery
Jeff Layton
Jeff Layton
Christoph Hellwig
Gu Zheng
Tim Chen
Dave Chinner
Sasha Levin
Johannes Weiner
Steven Whitehouse