During its tree walk, btrfs_drop_snapshot() will skip any shared
subtrees it encounters. This is incorrect when we have qgroups
turned on as those subtrees need to have their contents
accounted. In particular, the case we're concerned with is when
removing our snapshot root leaves the subtree with only one root
reference.
In those cases we need to find the last remaining root and add
each extent in the subtree to the corresponding qgroup exclusive
counts.
This patch implements the shared subtree walk and a new qgroup
operation, BTRFS_QGROUP_OPER_SUB_SUBTREE. When an operation of
this type is encountered during qgroup accounting, we search for
any root references to that extent and in the case that we find
only one reference left, we go ahead and do the math on it's
exclusive counts.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Before processing the extent buffer, acquire a read lock on it, so
that we're safe against concurrent updates on the extent buffer.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Before I extended the no_quota arg to btrfs_dec/inc_ref because I didn't
understand how snapshot delete was using it and assumed that we needed the
quota operations there. With Mark's work this has turned out to be not the
case, we _always_ need to use no_quota for btrfs_dec/inc_ref, so just drop the
argument and make __btrfs_mod_ref call it's process function with no_quota set
always. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
This has been discussed in thread:
http://thread.gmane.org/gmane.comp.file-systems.btrfs/32528
and this patch implements this proposal:
http://thread.gmane.org/gmane.comp.file-systems.btrfs/32536
Works fine for "clean" raid profiles where the raid factor correction
does the right job. Otherwise it's pessimistic and may show low space
although there's still some left.
The df nubmers are lightly wrong in case of mixed block groups, but this
is not a major usecase and can be addressed later.
The RAID56 numbers are wrong almost the same way as before and will be
addressed separately.
CC: Hugo Mills <hugo@carfax.org.uk>
CC: cwillu <cwillu@cwillu.com>
CC: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Fix the broken check for calling sys_fallocate() on an active swapfile,
introduced by commit 0790b31b69 ("fs: disallow all fallocate
operation on active swapfile").
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The direct-io.c rewrite to use the iov_iter infrastructure stopped updating
the size field in struct dio_submit, and thus rendered the check for
allowing asynchronous completions to always return false. Fix this by
comparing it to the count of bytes in the iov_iter instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Tim Chen <tim.c.chen@linux.intel.com>
Tested-by: Tim Chen <tim.c.chen@linux.intel.com>
Correctly assemble the client UUID by OR'ing in the flags rather than
assigning them over the other components.
Reported-by: Himangi Saraogi <himangi774@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs fixes from Christoph Hellwig:
"A vfsmount leak fix, and a compile warning fix"
* 'vfs-for-3.16' of git://git.infradead.org/users/hch/vfs:
fs: umount on symlink leaks mnt count
direct-io: fix uninitialized warning in do_direct_IO()
Pull fuse fixes from Miklos Szeredi:
"These two pathes fix issues with the kernel-userspace protocol changes
in v3.15"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: add FUSE_NO_OPEN_SUPPORT flag to INIT
fuse: s_time_gran fix
Currently umount on symlink blocks following umount:
/vz is separate mount
# ls /vz/ -al | grep test
drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir
lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir
# umount -l /vz/testlink
umount: /vz/testlink: not mounted (expected)
# lsof /vz
# umount /vz
umount: /vz: device is busy. (unexpected)
In this case mountpoint_last() gets an extra refcount on path->mnt
Signed-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Ian Kent <raven@themaw.net>
Acked-by: Jeff Layton <jlayton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
The following warnings:
fs/direct-io.c: In function ‘__blockdev_direct_IO’:
fs/direct-io.c:1011:12: warning: ‘to’ may be used uninitialized in this function [-Wmaybe-uninitialized]
fs/direct-io.c:913:16: note: ‘to’ was declared here
fs/direct-io.c:1011:12: warning: ‘from’ may be used uninitialized in this function [-Wmaybe-uninitialized]
fs/direct-io.c:913:10: note: ‘from’ was declared here
are false positive because dio_get_page() either fails, or sets both
'from' and 'to'.
Paul Bolle said ...
Maybe it's better to move initializing "to" and "from" out of
dio_get_page(). That _might_ make it easier for both the the reader and
the compiler to understand what's going on. Something like this:
Christoph Hellwig said ...
The fix of moving the code definitively looks nicer, while I think
uninitialized_var is horrible wart that won't get anywhere near my code.
Boaz Harrosh: I agree with Christoph and Paul
Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull nfsd bugfix from Bruce Fields:
"Another regression from the xdr encoding rewrite"
* 'for-3.16' of git://linux-nfs.org/~bfields/linux:
NFSD: Fix crash encoding lock reply on 32-bit
If a filesystem uses simple_xattr to support user extended attributes,
LTP setxattr01 and xfstests generic/062 fail with "Cannot allocate
memory": simple_xattr_alloc()'s wrap-around test mistakenly excludes
values of zero size. Fix that off-by-one (but apparently no filesystem
needs them yet).
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 079148b919 ("coredump: factor out the setting of PF_DUMPCORE")
cleaned up the setting of PF_DUMPCORE by removing it from all the
linux_binfmt->core_dump() and moving it to zap_threads().But this ended
up clearing all the previously set flags. This causes issues during
core generation when tsk->flags is checked again (eg. for PF_USED_MATH
to dump floating point registers). Fix this.
Signed-off-by: Silesh C V <svellattu@mvista.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 8c7424cff6 "nfsd4: don't try to encode conflicting owner if low
on space" forgot to free conf->data in nfsd4_encode_lockt and before
sign conf->data to NULL in nfsd4_encode_lock_denied, causing a leak.
Worse, kfree() can be called on an uninitialized pointer in the case of
a succesful lock (or one that fails for a reason other than a conflict).
(Note that lock->lk_denied.ld_owner.data appears it should be zero here,
until you notice that it's one arm of a union the other arm of which is
written to in the succesful case by the
memcpy(&lock->lk_resp_stateid, &lock_stp->st_stid.sc_stateid,
sizeof(stateid_t));
in nfsd4_lock(). In the 32-bit case this overwrites ld_owner.data.)
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Fixes: 8c7424cff6 ""nfsd4: don't try to encode conflicting owner if low on space"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Here some additional changes to set a capability flag so that clients can
detect when it's appropriate to return -ENOSYS from open.
This amends the following commit introduced in 3.14:
7678ac5061 fuse: support clients that don't implement 'open'
However we can only add the flag to 3.15 and later since there was no
protocol version update in 3.14.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: <stable@vger.kernel.org> # v3.15+
Pull btrfs fixes from Chris Mason:
"We have two more fixes in my for-linus branch.
I was hoping to also include a fix for a btrfs deadlock with
compression enabled, but we're still nailing that one down"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: test for valid bdev before kobj removal in btrfs_rm_device
Btrfs: fix abnormal long waiting in fsync
Highlights include;
- Stable fix for an NFSv3 posix ACL regression
- Multiple fixes for regressions to the NFS generic read/write code
- Fix page splitting bugs that come into play when a small rsize/wsize
read/write needs to be sent again (due to error conditions or page
redirty).
- Fix nfs_wb_page_cancel, which is called by the "invalidatepage" method
- Fix 2 compile warnings about unused variables.
- Fix a performance issue affecting unstable writes.
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Merge tag 'nfs-for-3.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client fixes from Trond Myklebust:
"Apologies for the relative lateness of this pull request, however the
commits fix some issues with the NFS read/write code updates in
3.16-rc1 that can cause serious Oopsing when using small r/wsize. The
delay was mainly due to extra testing to make sure that the fixes
behave correctly.
Highlights include;
- Stable fix for an NFSv3 posix ACL regression
- Multiple fixes for regressions to the NFS generic read/write code:
- Fix page splitting bugs that come into play when a small
rsize/wsize read/write needs to be sent again (due to error
conditions or page redirty)
- Fix nfs_wb_page_cancel, which is called by the "invalidatepage"
method
- Fix 2 compile warnings about unused variables
- Fix a performance issue affecting unstable writes"
* tag 'nfs-for-3.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: Don't reset pg_moreio in __nfs_pageio_add_request
NFS: Remove 2 unused variables
nfs: handle multiple reqs in nfs_wb_page_cancel
nfs: handle multiple reqs in nfs_page_async_flush
nfs: change find_request to find_head_request
nfs: nfs_page should take a ref on the head req
nfs: mark nfs_page reqs with flag for extra ref
nfs: only show Posix ACLs in listxattr if actually present
commit 99994cd btrfs: dev delete should remove sysfs entry
added a btrfs_kobj_rm_device, which dereferences device->bdev...
right after we check whether device->bdev might be NULL.
I don't honestly know if it's possible to have a NULL device->bdev
here, but assuming that it is (given the test), we need to move
the kobject removal to be under that test.
(Coverity spotted this)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
xfstests generic/127 detected this problem.
With commit 7fc34a62ca, now fsync will only flush
data within the passed range. This is the cause of the above problem,
-- btrfs's fsync has a stage called 'sync log' which will wait for all the
ordered extents it've recorded to finish.
In xfstests/generic/127, with mixed operations such as truncate, fallocate,
punch hole, and mapwrite, we get some pre-allocated extents, and mapwrite will
mmap, and then msync. And I find that msync will wait for quite a long time
(about 20s in my case), thanks to ftrace, it turns out that the previous
fallocate calls 'btrfs_wait_ordered_range()' to flush dirty pages, but as the
range of dirty pages may be larger than 'btrfs_wait_ordered_range()' wants,
there can be some ordered extents created but not getting corresponding pages
flushed, then they're left in memory until we fsync which runs into the
stage 'sync log', and fsync will just wait for the system writeback thread
to flush those pages and get ordered extents finished, so the latency is
inevitable.
This adds a flush similar to btrfs_start_ordered_extent() in
btrfs_wait_logged_extents() to fix that.
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
flock, a change to use GFP_NOFS to avoid recursion on a rarely used
code path and a fix for a race relating to the glock lru.
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Merge tag 'gfs2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes
Pull gfs2 fixes from Steven Whitehouse:
"This patch set contains two minor docs/spelling fixes, some fixes for
flock, a change to use GFP_NOFS to avoid recursion on a rarely used
code path and a fix for a race relating to the glock lru"
* tag 'gfs2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes:
GFS2: fs/gfs2/rgrp.c: kernel-doc warning fixes
GFS2: memcontrol: Spelling s/invlidate/invalidate/
GFS2: Allow caching of glocks for flock
GFS2: Allow flocks to use normal glock dq rather than dq_wait
GFS2: replace count*size kzalloc by kcalloc
GFS2: Use GFP_NOFS when allocating glocks
GFS2: Fix race in glock lru glock disposal
GFS2: Only wait for demote when last holder is dequeued
Fixes for low memory perforamnce regressions and a quota inode handling
regression.
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Merge tag 'xfs-for-linus-3.16-rc5' of git://oss.sgi.com/xfs/xfs
Pull xfs fixes from Dave Chinner:
"Fixes for low memory perforamnce regressions and a quota inode
handling regression.
These are regression fixes for issues recently introduced - the change
in the stack switch location is fairly important, so I've held off
sending this update until I was sure that it still addresses the stack
usage problem the original solved. So while the commits in the xfs
tree are recent, it has been under tested for several weeks now"
* tag 'xfs-for-linus-3.16-rc5' of git://oss.sgi.com/xfs/xfs:
xfs: null unused quota inodes when quota is on
xfs: refine the allocation stack switch
Revert "xfs: block allocation work needs to be kswapd aware"
This patch removes the GLF_NOCACHE flag from the glocks associated with
flocks. There should be no good reason not to cache glocks for flocks:
they only force the glock to be demoted before they can be reacquired,
which can slow down performance and even cause glock hangs, especially
in cases where the flocks are held in Shared (SH) mode.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch allows flock glocks to use a non-blocking dequeue rather
than dq_wait. It also reverts the previous patch I had posted regarding
dq_wait. The reverted patch isn't necessarily a bad idea, but I decided
this might avoid unforeseen side effects, and was therefore safer.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Normally GFP_KERNEL is ok here, but there is now a rarely used code path
relating to deallocation of unlinked inodes (in certain corner cases)
which if hit at times of memory shortage can cause recursion while
trying to free memory.
One solution would be to try and move the gfs2_glock_get() call so
that it is no longer called while another glock is held, but that
doesn't look at all easy, so GFP_NOFS is the best solution for the
time being.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We must not leave items on the LRU list with GLF_LOCK set, since
they can be removed if the glock is brought back into use, which
may then potentially result in a hang, waiting for GLF_LOCK to
clear.
It doesn't happen very often, since it requires a glock that has
not been used for a long time to be brought back into use at the
same moment that the shrinker is part way through disposing of
glocks.
The fix is to set GLF_LOCK at a later time, when we already know
that the other locks can be obtained. Also, we now only release
the lru_lock in case a resched is needed, rather than on every
iteration.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Function gfs2_glock_dq_wait is supposed to dequeue a glock and then
wait for the lock to be demoted. The problem is, if this is a shared
lock, its demote will depend on the other holders, which means you
might end up waiting forever because the other process is blocked.
This problem is especially apparent when dealing with nested flocks.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Pull quota fix from Jan Kara:
"Fix locking of dquot shrinker"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
quota: missing lock in dqcache_shrink_scan()
Commit 1ab6c4997e (fs: convert fs shrinkers to new scan/count API)
accidentally removed locking from quota shrinker. Fix it -
dqcache_shrink_scan() should use dq_list_lock to protect the
scan on free_dquots list.
CC: stable@vger.kernel.org
Fixes: 1ab6c4997e
Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Pull fuse fixes from Miklos Szeredi:
"This contains miscellaneous fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: replace count*size kzalloc by kcalloc
fuse: release temporary page if fuse_writepage_locked() failed
fuse: restructure ->rename2()
fuse: avoid scheduling while atomic
fuse: handle large user and group ID
fuse: inode: drop cast
fuse: ignore entry-timeout on LOOKUP_REVAL
fuse: timeout comparison fix
When quota is on, it is expected that unused quota inodes have a
value of NULLFSINO. The changes to support a separate project quota
in 3.12 broken this rule for non-project quota inode enabled
filesystem, as the code now refuses to write the group quota inode
if neither group or project quotas are enabled. This regression was
introduced by commit d892d58 ("xfs: Start using pquotaino from the
superblock").
In this case, we should be writing NULLFSINO rather than nothing to
ensure that we leave the group quota inode in a valid state while
quotas are enabled.
Failure to do so doesn't cause a current kernel to break - the
separate project quota inodes introduced translation code to always
treat a zero inode as NULLFSINO. This was introduced by commit
0102629 ("xfs: Initialize all quota inodes to be NULLFSINO") with is
also in 3.12 but older kernels do not do this and hence taking a
filesystem back to an older kernel can result in quotas failing
initialisation at mount time. When that happens, we see this in
dmesg:
[ 1649.215390] XFS (sdb): Mounting Filesystem
[ 1649.316894] XFS (sdb): Failed to initialize disk quotas.
[ 1649.316902] XFS (sdb): Ending clean mount
By ensuring that we write NULLFSINO to quota inodes that aren't
active, we avoid this problem. We have to be really careful when
determining if the quota inodes are active or not, because we don't
want to write a NULLFSINO if the quota inodes are active and we
simply aren't updating them.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
The allocation stack switch at xfs_bmapi_allocate() has served it's
purpose, but is no longer a sufficient solution to the stack usage
problem we have in the XFS allocation path.
Whilst the kernel stack size is now 16k, that is not a valid reason
for undoing all our "keep stack usage down" modifications. What it
does allow us to do is have the freedom to refine and perfect the
modifications knowing that if we get it wrong it won't blow up in
our faces - we have a safety net now.
This is important because we still have the issue of older kernels
having smaller stacks and that they are still supported and are
demonstrating a wide range of different stack overflows. Red Hat
has several open bugs for allocation based stack overflows from
directory modifications and direct IO block allocation and these
problems still need to be solved. If we can solve them upstream,
then distro's won't need to bake their own unique solutions.
To that end, I've observed that every allocation based stack
overflow report has had a specific characteristic - it has happened
during or directly after a bmap btree block split. That event
requires a new block to be allocated to the tree, and so we
effectively stack one allocation stack on top of another, and that's
when we get into trouble.
A further observation is that bmap btree block splits are much rarer
than writeback allocation - over a range of different workloads I've
observed the ratio of bmap btree inserts to splits ranges from 100:1
(xfstests run) to 10000:1 (local VM image server with sparse files
that range in the hundreds of thousands to millions of extents).
Either way, bmap btree split events are much, much rarer than
allocation events.
Finally, we have to move the kswapd state to the allocation workqueue
work when allocation is done on behalf of kswapd. This is proving to
cause significant perturbation in performance under memory pressure
and appears to be generating allocation deadlock warnings under some
workloads, so avoiding the use of a workqueue for the majority of
kswapd writeback allocation will minimise the impact of such
behaviour.
Hence it makes sense to move the stack switch to xfs_btree_split()
and only do it for bmap btree splits. Stack switches during
allocation will be much rarer, so there won't be significant
performacne overhead caused by switching stacks. The worse case
stack from all allocation paths will be split, not just writeback.
And the majority of memory allocations will be done in the correct
context (e.g. kswapd) without causing additional latency, and so we
simplify the memory reclaim interactions between processes,
workqueues and kswapd.
The worst stack I've been able to generate with this patch in place
is 5600 bytes deep. It's very revealing because we exit XFS at:
37) 1768 64 kmem_cache_alloc+0x13b/0x170
about 1800 bytes of stack consumed, and the remaining 3800 bytes
(and 36 functions) is memory reclaim, swap and the IO stack. And
this occurs in the inode allocation from an open(O_CREAT) syscall,
not writeback.
The amount of stack being used is much less than I've previously be
able to generate - fs_mark testing has been able to generate stack
usage of around 7k without too much trouble; with this patch it's
only just getting to 5.5k. This is primarily because the metadata
allocation paths (e.g. directory blocks) are no longer causing
double splits on the same stack, and hence now stack tracing is
showing swapping being the worst stack consumer rather than XFS.
Performance of fs_mark inode create workloads is unchanged.
Performance of fs_mark async fsync workloads is consistently good
with context switches reduced by around 150,000/s (30%).
Performance of dbench, streaming IO and postmark is unchanged.
Allocation deadlock warnings have not been seen on the workloads
that generated them since adding this patch.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This reverts commit 1f6d64829d.
This commit resulted in regressions in performance in low
memory situations where kswapd was doing writeback of delayed
allocation blocks. It resulted in significant parallelism of the
kswapd work and with the special kswapd flags meant that hundreds of
active allocation could dip into kswapd specific memory reserves and
avoid being throttled. This cause a large amount of performance
variation, as well as random OOM-killer invocations that didn't
previously exist.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
As of commit f8567a3845 it is now possible to
have put_reqs_available() called from irq context. While put_reqs_available()
is per cpu, it did not protect itself from interrupts on the same CPU. This
lead to aio_complete() corrupting the available io requests count when run
under a heavy O_DIRECT workloads as reported by Robert Elliott. Fix this by
disabling irq updates around the per cpu batch updates of reqs_available.
Many thanks to Robert and folks for testing and tracking this down.
Reported-by: Robert Elliot <Elliott@hp.com>
Tested-by: Robert Elliot <Elliott@hp.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@infradead.org>
Cc: stable@vger.kenel.org
(introduced in 3.15) that can end up triggering a file system
corruption error after a journal replay. (It shouldn't lead to any
actual data corruption, but it is scary and can force file systems to
be remounted read-only, etc.)
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 bugfixes from Ted Ts'o:
"More bug fixes for ext4 -- most importantly, a fix for a bug
introduced in 3.15 that can end up triggering a file system corruption
error after a journal replay.
It shouldn't lead to any actual data corruption, but it is scary and
can force file systems to be remounted read-only, etc"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix potential null pointer dereference in ext4_free_inode
ext4: fix a potential deadlock in __ext4_es_shrink()
ext4: revert commit which was causing fs corruption after journal replays
ext4: disable synchronous transaction batching if max_batch_time==0
ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()
ext4: clarify error count warning messages
ext4: fix unjournalled bg descriptor while initializing inode bitmap
Once we've started sending unstable NFS writes, we do not want to
clear pg_moreio, or we may end up sending the very last request as
a stable write if the commit lists are still empty.
Do, however, reset pg_moreio in the case where we end up having to
recoalesce the write if an attempt to use pNFS failed.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Use nfs_lock_and_join_requests to merge all subrequests into the head request -
this cancels and dereferences all subrequests.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Change nfs_find_and_lock_request so nfs_page_async_flush can handle multiple
requests in a page. There is only one request for a page the first time
nfs_page_async_flush is called, but if a write or commit fails, async_flush
is called again and there may be multiple requests associated with the page.
The solution is to merge all the requests in a page group into a single
request before calling nfs_pageio_add_request.
Rename nfs_find_and_lock_request to nfs_lock_and_join_requests and
change it to first lock all requests for the page, then cancel and merge
all subrequests into the head request.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs_page_find_request_locked* should find the head request for that page.
Rename the functions and add comments to make this clear, and fix a bug
that could return a subrequest when page_private isn't set on the page.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs_pages that aren't the the head of a group must take a reference on the
head as long as ->wb_head is set to it. This stops the head from hitting
a refcount of 0 while there is still an active nfs_page for the page group.
This avoids kref warnings in the writeback code when the page group head
is found and referenced.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Change the use of PG_INODE_REF - set it when taking extra reference on
subrequests and take care to only release once for each request.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
