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Author SHA1 Message Date
Dave Chinner
1316d4da3f xfs: unpin stale inodes directly in IOP_COMMITTED
When inodes are marked stale in a transaction, they are treated
specially when the inode log item is being inserted into the AIL.
It tries to avoid moving the log item forward in the AIL due to a
race condition with the writing the underlying buffer back to disk.
The was "fixed" in commit de25c18 ("xfs: avoid moving stale inodes
in the AIL").

To avoid moving the item forward, we return a LSN smaller than the
commit_lsn of the completing transaction, thereby trying to trick
the commit code into not moving the inode forward at all. I'm not
sure this ever worked as intended - it assumes the inode is already
in the AIL, but I don't think the returned LSN would have been small
enough to prevent moving the inode. It appears that the reason it
worked is that the lower LSN of the inodes meant they were inserted
into the AIL and flushed before the inode buffer (which was moved to
the commit_lsn of the transaction).

The big problem is that with delayed logging, the returning of the
different LSN means insertion takes the slow, non-bulk path.  Worse
yet is that insertion is to a position -before- the commit_lsn so it
is doing a AIL traversal on every insertion, and has to walk over
all the items that have already been inserted into the AIL. It's
expensive.

To compound the matter further, with delayed logging inodes are
likely to go from clean to stale in a single checkpoint, which means
they aren't even in the AIL at all when we come across them at AIL
insertion time. Hence these were all getting inserted into the AIL
when they simply do not need to be as inodes marked XFS_ISTALE are
never written back.

Transactional/recovery integrity is maintained in this case by the
other items in the unlink transaction that were modified (e.g. the
AGI btree blocks) and committed in the same checkpoint.

So to fix this, simply unpin the stale inodes directly in
xfs_inode_item_committed() and return -1 to indicate that the AIL
insertion code does not need to do any further processing of these
inodes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-07-06 15:44:40 -05:00
Dave Chinner
4a33821236 xfs: prevent bogus assert when trying to remove non-existent attribute
If the attribute fork on an inode is in btree format and has
multiple levels (i.e node format rather than leaf format), then a
lookup failure will trigger an assert failure in xfs_da_path_shift
if the flag XFS_DA_OP_OKNOENT is not set. This flag is used to
indicate to the directory btree code that not finding an entry is
not a fatal error. In the case of doing a lookup for a directory
name removal, this is valid as a user cannot insert an arbitrary
name to remove from the directory btree.

However, in the case of the attribute tree, a user has direct
control over the attribute name and can ask for any random name to
be removed without any validation. In this case, fsstress is asking
for a non-existent user.selinux attribute to be removed, and that is
causing xfs_da_path_shift() to fall off the bottom of the tree where
it asserts that a lookup failure is allowed. Because the flag is not
set, we die a horrible death on a debug enable kernel.

Prevent this assert from firing on attribute removes by adding the
op_flag XFS_DA_OP_OKNOENT to atribute removal operations.

Discovered when testing on a SELinux enabled system by fsstress in
test 070 by trying to remove a non-existent user.selinux attribute.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-06-23 22:13:51 -05:00
Dave Chinner
df4368a146 xfs: clear XFS_IDIRTY_RELEASE on truncate down
When an inode is truncated down, speculative preallocation is
removed from the inode. This should also reset the state bits for
controlling whether preallocation is subsequently removed when the
file is next closed. The flag is not being cleared, so repeated
operations on a file that first involve a truncate (e.g. multiple
repeated dd invocations on a file) give different file layouts for
the second and subsequent invocations.

Fix this by clearing the XFS_IDIRTY_RELEASE state bit when the
XFS_ITRUNCATED bit is detected in xfs_release() and hence ensure
that speculative delalloc is removed on files that have been
truncated down.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-06-23 22:13:46 -05:00
Dave Chinner
778e24bb6d xfs: reset inode per-lifetime state when recycling it
XFS inodes has several per-lifetime state fields that determine the
behaviour of the inode. These state fields are not all reset when an
inode is reused from the reclaimable state.

This can lead to unexpected behaviour of the new inode such as
speculative preallocation not being truncated away in the expected
manner for local files until the inode is subsequently truncated,
freed or cycles out of the cache. It can also lead to an inode being
considered to be a filestream inode or having been truncated when
that is not the case.

Rework the reinitialisation of the inode when it is recycled to
ensure that it is pristine before it is reused. While there, also
fix the resetting of state flags in the recycling error paths so the
inode does not become unreclaimable.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-06-23 22:13:31 -05:00
Christoph Hellwig
a27a263bae xfs: make log devices with write back caches work
There's no reason not to support cache flushing on external log devices.
The only thing this really requires is flushing the data device first
both in fsync and log commits.  A side effect is that we also have to
remove the barrier write test during mount, which has been superflous
since the new FLUSH+FUA code anyway.  Also use the chance to flush the
RT subvolume write cache before the fsync commit, which is required
for correct semantics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-06-16 10:52:39 -05:00
Al Viro
c46a131c0c xfs: fix ->mknod() return value on xfs_get_acl() failure
->mknod() should return negative on errors and PTR_ERR() gives
already negative value...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-06-14 11:02:13 -05:00
Christoph Hellwig
aa38572954 fs: pass exact type of data dirties to ->dirty_inode
Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or
anything else, so that the filesystem can track internally if it
needs to push out a transaction for fdatasync or not.

This is just the prototype change with no user for it yet.  I plan
to push large XFS changes for the next merge window, and getting
this trivial infrastructure in this window would help a lot to avoid
tree interdependencies.

Also remove incorrect comments that ->dirty_inode can't block.  That
has been changed a long time ago, and many implementations rely on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-27 07:04:40 -04:00
Linus Torvalds
8a0599dd24 Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: correctly decrement the extent buffer index in xfs_bmap_del_extent
  xfs: check for valid indices in xfs_iext_get_ext and xfs_iext_idx_to_irec
  xfs: fix up asserts in xfs_iflush_fork
  xfs: do not do pointer arithmetic on extent records
  xfs: do not use unchecked extent indices in xfs_bunmapi
  xfs: do not use unchecked extent indices in xfs_bmapi
  xfs: do not use unchecked extent indices in xfs_bmap_add_extent_*
  xfs: remove if_lastex
  xfs: remove the unused XFS_BMAPI_RSVBLOCKS flag
  xfs: do not discard alloc btree blocks
  xfs: add online discard support
2011-05-26 10:49:11 -07:00
Christoph Hellwig
233eebb9a9 xfs: correctly decrement the extent buffer index in xfs_bmap_del_extent
The code in xfs_bmap_del_extent does not correctly decrement the
extent buffer index when deleting a whole extent.  Most of the time
this gets caught by checks in xfs_bmapi that work around it and
decrement it manually and thus wasn't noticed so far.

Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:38 -05:00
Christoph Hellwig
87bef1812d xfs: check for valid indices in xfs_iext_get_ext and xfs_iext_idx_to_irec
Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:37 -05:00
Christoph Hellwig
ab1908a5bb xfs: fix up asserts in xfs_iflush_fork
Remove asserts in xfs_iflush_fork that would call xfs_iext_get_ext
with a potentially invalid extent buffer index.

Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:37 -05:00
Christoph Hellwig
f1c63b73cf xfs: do not do pointer arithmetic on extent records
We need to call xfs_iext_get_ext for the previous extent to get a
valid pointer, and can't just do pointer arithmetics as they might
be in different pages.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:37 -05:00
Christoph Hellwig
00239acf36 xfs: do not use unchecked extent indices in xfs_bunmapi
Make sure to only call xfs_iext_get_ext after we've validate the
extent index when moving on to the next index in xfs_bunmapi.  Also
remove the old workaround for too large indices that has been
superceeded by the proper fix in xfs_bmap_del_extent.

Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:37 -05:00
Christoph Hellwig
5690f92199 xfs: do not use unchecked extent indices in xfs_bmapi
Make sure to only call xfs_iext_get_ext after we've validate the
extent index when moving on to the next index in xfs_bmapi.

Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:37 -05:00
Christoph Hellwig
2f2b3220b0 xfs: do not use unchecked extent indices in xfs_bmap_add_extent_*
Make sure to only call xfs_iext_get_ext after we've validate the
extent index in the various xfs_bmap_add_extent_* helpers.

Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:37 -05:00
Christoph Hellwig
ec90c55634 xfs: remove if_lastex
The if_lastex field in struct xfs_ifork is only used as a temporary
index during xfs_bmapi and xfs_bunmapi.  Instead of using the inode
fork to store it keep it local in the callchain.  Fortunately this
is very easy as we already pass a stack copy of it down the whole
chain which can simplify be changed to be passed by reference.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:37 -05:00
Christoph Hellwig
548932739b xfs: remove the unused XFS_BMAPI_RSVBLOCKS flag
The XFS_BMAPI_RSVBLOCKS is unused, and as far as I can see has
always been.  Remove it to simplify the bmapi implementation and
conserve stack space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-25 10:48:36 -05:00
Ying Han
1495f230fa vmscan: change shrinker API by passing shrink_control struct
Change each shrinker's API by consolidating the existing parameters into
shrink_control struct.  This will simplify any further features added w/o
touching each file of shrinker.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: fix warning]
[kosaki.motohiro@jp.fujitsu.com: fix up new shrinker API]
[akpm@linux-foundation.org: fix xfs warning]
[akpm@linux-foundation.org: update gfs2]
Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:26 -07:00
Christoph Hellwig
55a7bc5a30 xfs: do not discard alloc btree blocks
Blocks for the allocation btree are allocated from and released to
the AGFL, and thus frequently reused.  Even worse we do not have an
easy way to avoid using an AGFL block when it is discarded due to
the simple FILO list of free blocks, and thus can frequently stall
on blocks that are currently undergoing a discard.

Add a flag to the busy extent tracking structure to skip the discard
for allocation btree blocks.  In normal operation these blocks are
reused frequently enough that there is no need to discard them
anyway, but if they spill over to the allocation btree as part of a
balance we "leak" blocks that we would otherwise discard.  We could
fix this by adding another flag and keeping these block in the
rbtree even after they aren't busy any more so that we could discard
them when they migrate out of the AGFL.  Given that this would cause
significant overhead I don't think it's worthwile for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-24 11:17:22 -05:00
Christoph Hellwig
e84661aa84 xfs: add online discard support
Now that we have reliably tracking of deleted extents in a
transaction we can easily implement "online" discard support
which calls blkdev_issue_discard once a transaction commits.

The actual discard is a two stage operation as we first have
to mark the busy extent as not available for reuse before we
can start the actual discard.  Note that we don't bother
supporting discard for the non-delaylog mode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-24 11:17:13 -05:00
Linus Torvalds
a77febbef1 Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: obey minleft values during extent allocation correctly
  xfs: reset buffer pointers before freeing them
  xfs: avoid getting stuck during async inode flushes
  xfs: fix xfs_itruncate_start tracing
  xfs: fix duplicate workqueue initialisation
  xfs: kill off xfs_printk()
  xfs: fix race condition in AIL push trigger
  xfs: make AIL target updates and compares 32bit safe.
  xfs: always push the AIL to the target
  xfs: exit AIL push work correctly when AIL is empty
  xfs: ensure reclaim cursor is reset correctly at end of AG
  xfs: add an x86 compat handler for XFS_IOC_ZERO_RANGE
  xfs: fix compiler warning in xfs_trace.h
  xfs: cleanup duplicate initializations
  xfs: reduce the number of pagb_lock roundtrips in xfs_alloc_clear_busy
  xfs: exact busy extent tracking
  xfs: do not immediately reuse busy extent ranges
  xfs: optimize AGFL refills
2011-05-23 15:19:16 -07:00
Linus Torvalds
57d19e80f4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  b43: fix comment typo reqest -> request
  Haavard Skinnemoen has left Atmel
  cris: typo in mach-fs Makefile
  Kconfig: fix copy/paste-ism for dell-wmi-aio driver
  doc: timers-howto: fix a typo ("unsgined")
  perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
  md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
  treewide: fix a few typos in comments
  regulator: change debug statement be consistent with the style of the rest
  Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
  audit: acquire creds selectively to reduce atomic op overhead
  rtlwifi: don't touch with treewide double semicolon removal
  treewide: cleanup continuations and remove logging message whitespace
  ath9k_hw: don't touch with treewide double semicolon removal
  include/linux/leds-regulator.h: fix syntax in example code
  tty: fix typo in descripton of tty_termios_encode_baud_rate
  xtensa: remove obsolete BKL kernel option from defconfig
  m68k: fix comment typo 'occcured'
  arch:Kconfig.locks Remove unused config option.
  treewide: remove extra semicolons
  ...
2011-05-23 09:12:26 -07:00
Dave Chinner
bf59170a66 xfs: obey minleft values during extent allocation correctly
When allocating an extent that is long enough to consume the
remaining free space in an AG, we need to ensure that the allocation
leaves enough space in the AG for any subsequent bmap btree blocks
that are needed to track the new extent. These have to be allocated
in the same AG as we only reserve enough blocks in an allocation
transaction for modification of the freespace trees in a single AG.

xfs_alloc_fix_minleft() has been considering blocks on the AGFL as
free blocks available for extent and bmbt block allocation, which is
not correct - blocks on the AGFL are there exclusively for the use
of the free space btrees. As a result, when minleft is less than the
number of blocks on the AGFL, xfs_alloc_fix_minleft() does not trim
the given extent to leave minleft blocks available for bmbt
allocation, and hence we can fail allocation during bmbt record
insertion.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-19 12:03:48 -05:00
Dave Chinner
44396476a0 xfs: reset buffer pointers before freeing them
When we free a vmapped buffer, we need to ensure the vmap address
and length we free is the same as when it was allocated. In various
places in the log code we change the memory the buffer is pointing
to before issuing IO, but we never reset the buffer to point back to
it's original memory (or no memory, if that is the case for the
buffer).

As a result, when we free the buffer it points to memory that is
owned by something else and attempts to unmap and free it. Because
the range does not match any known mapped range, it can trigger
BUG_ON() traps in the vmap code, and potentially corrupt the vmap
area tracking.

Fix this by always resetting these buffers to their original state
before freeing them.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-19 12:03:45 -05:00
Dave Chinner
ee58abdfcc xfs: avoid getting stuck during async inode flushes
When the underlying inode buffer is locked and xfs_sync_inode_attr()
is doing a non-blocking flush, xfs_iflush() can return EAGAIN.  When
this happens, clear the error rather than returning it to
xfs_inode_ag_walk(), as returning EAGAIN will result in the AG walk
delaying for a short while and trying again. This can result in
background walks getting stuck on the one AG until inode buffer is
unlocked by some other means.

This behaviour was noticed when analysing event traces followed by
code inspection and verification of the fix via further traces.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-19 12:03:42 -05:00
Dave Chinner
e57375153d xfs: fix xfs_itruncate_start tracing
Variables are ordered incorrectly in trace call.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-19 12:03:36 -05:00
Dave Chinner
1beb65ad45 xfs: fix duplicate workqueue initialisation
The workqueue initialisation function is called twice when
initialising the XFS subsystem. Remove the second initialisation
call.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-19 12:03:24 -05:00
Joe Perches
e69522a8cc xfs: kill off xfs_printk()
xfs_alert_tag() can be defined using xfs_alert(), and thereby avoid
using xfs_printk() altogether.  This is the only remaining use of
xfs_printk(), so changing it this way means xfs_printk() can simply
be eliminated.can simply be eliminated.can simply be eliminated.can
simply be eliminated.can simply be eliminated.can simply be
eliminated.can simply be eliminated.can simply be eliminated.can
simply be eliminated.

Also add format checking to the non-debug inline function xfs_debug.
Miscellaneous function prototype argument alignment.

(Updated to delete the definition of xfs_printk(), which is
no longer used or needed.)

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-19 11:38:09 -05:00
Justin P. Mattock
70f23fd66b treewide: fix a few typos in comments
- kenrel -> kernel
- whetehr -> whether
- ttt -> tt
- sss -> ss

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-10 10:16:21 +02:00
Dave Chinner
7ac956576d xfs: fix race condition in AIL push trigger
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One is caused by a
race condition in determining whether there is a psh in progress or
not.

The XFS_AIL_PUSHING_BIT is used to determine whether a push is
currently in progress.  When the AIL push work completes, it checked
whether the target changed and cleared the PUSHING bit to allow a
new push to be requeued. The race condition is as follows:

	Thread 1		push work

	smp_wmb()
				smp_rmb()
				check ailp->xa_target unchanged
	update ailp->xa_target
	test/set PUSHING bit
	does not queue
				clear PUSHING bit
				does not requeue

Now that the push target is updated, new attempts to push the AIL
will not trigger as the push target will be the same, and hence
despite trying to push the AIL we won't ever wake it again.

The fix is to ensure that the AIL push work clears the PUSHING bit
before it checks if the target is unchanged.

As a result, both push triggers operate on the same test/set bit
criteria, so even if we race in the push work and miss the target
update, the thread requesting the push will still set the PUSHING
bit and queue the push work to occur. For safety sake, the same
queue check is done if the push work detects the target change,
though only one of the two will will queue new work due to the use
of test_and_set_bit() checks.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

(cherry picked from commit e4d3c4a43b)
2011-05-09 18:35:04 -05:00
Dave Chinner
fe0da76731 xfs: make AIL target updates and compares 32bit safe.
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One of the problems
noticed was that updates of the push target are not 32 bit safe as
the target is a 64 bit value.

We cannot copy a 64 bit LSN without the possibility of corrupting
the result when racing with another updating thread. We have
function to do this update safely without needing to care about
32/64 bit issues - xfs_trans_ail_copy_lsn() - so use that when
updating the AIL push target.

Also move the reading of the target in the push work inside the AIL
lock, and use XFS_LSN_CMP() for the unlocked comparison during work
termination to close read holes as well.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

(cherry picked from commit fd5670f22f)
2011-05-09 18:35:04 -05:00
Dave Chinner
50e86686df xfs: always push the AIL to the target
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One of the problems
discovered is a target mismatch between the item pushing loop and
the target itself.

The push trigger checks for the target increasing (i.e. new target >
current) while the push loop only pushes items that have a LSN <
current. As a result, we can get the situation where the push target
is X, the items at the tail of the AIL have LSN X and they don't get
pushed. The push work then completes thinking it is done, and cannot
be restarted until the push target increases to >= X + 1. If the
push target then never increases (because the tail is not moving),
then we never run the push work again and we stall.

Fix it by making sure log items with a LSN that matches the target
exactly are pushed during the loop.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

(cherry picked from commit cb64026b6e)
2011-05-09 18:35:03 -05:00
Dave Chinner
9e7004e741 xfs: exit AIL push work correctly when AIL is empty
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. The main cause is a
regression where a work exit path fails to clear the PUSHING state
and recheck the target correctly.

Make both exit paths do the same PUSHING bit clearing and target
checking when the "no more work to be done" condition is hit.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

(cherry picked from commit ea35a20021)
2011-05-09 18:35:03 -05:00
Dave Chinner
228d62dd3f xfs: ensure reclaim cursor is reset correctly at end of AG
On a 32 bit highmem PowerPC machine, the XFS inode cache was growing
without bound and exhausting low memory causing the OOM killer to be
triggered. After some effort, the problem was reproduced on a 32 bit
x86 highmem machine.

The problem is that the per-ag inode reclaim index cursor was not
getting reset to the start of the AG if the radix tree tag lookup
found no more reclaimable inodes. Hence every further reclaim
attempt started at the same index beyond where any reclaimable
inodes lay, and no further background reclaim ever occurred from the
AG.

Without background inode reclaim the VM driven cache shrinker
simply cannot keep up with cache growth, and OOM is the result.

While the change that exposed the problem was the conversion of the
inode reclaim to use work queues for background reclaim, it was not
the cause of the bug. The bug was introduced when the cursor code
was added, just waiting for some weird configuration to strike....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-By: Christian Kujau <lists@nerdbynature.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

(cherry picked from commit b223221956)
2011-05-09 18:35:03 -05:00
Dave Chinner
e4d3c4a43b xfs: fix race condition in AIL push trigger
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One is caused by a
race condition in determining whether there is a psh in progress or
not.

The XFS_AIL_PUSHING_BIT is used to determine whether a push is
currently in progress.  When the AIL push work completes, it checked
whether the target changed and cleared the PUSHING bit to allow a
new push to be requeued. The race condition is as follows:

	Thread 1		push work

	smp_wmb()
				smp_rmb()
				check ailp->xa_target unchanged
	update ailp->xa_target
	test/set PUSHING bit
	does not queue
				clear PUSHING bit
				does not requeue

Now that the push target is updated, new attempts to push the AIL
will not trigger as the push target will be the same, and hence
despite trying to push the AIL we won't ever wake it again.

The fix is to ensure that the AIL push work clears the PUSHING bit
before it checks if the target is unchanged.

As a result, both push triggers operate on the same test/set bit
criteria, so even if we race in the push work and miss the target
update, the thread requesting the push will still set the PUSHING
bit and queue the push work to occur. For safety sake, the same
queue check is done if the push work detects the target change,
though only one of the two will will queue new work due to the use
of test_and_set_bit() checks.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-05-09 12:17:04 -05:00
Dave Chinner
fd5670f22f xfs: make AIL target updates and compares 32bit safe.
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One of the problems
noticed was that updates of the push target are not 32 bit safe as
the target is a 64 bit value.

We cannot copy a 64 bit LSN without the possibility of corrupting
the result when racing with another updating thread. We have
function to do this update safely without needing to care about
32/64 bit issues - xfs_trans_ail_copy_lsn() - so use that when
updating the AIL push target.

Also move the reading of the target in the push work inside the AIL
lock, and use XFS_LSN_CMP() for the unlocked comparison during work
termination to close read holes as well.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-05-09 12:17:04 -05:00
Dave Chinner
cb64026b6e xfs: always push the AIL to the target
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One of the problems
discovered is a target mismatch between the item pushing loop and
the target itself.

The push trigger checks for the target increasing (i.e. new target >
current) while the push loop only pushes items that have a LSN <
current. As a result, we can get the situation where the push target
is X, the items at the tail of the AIL have LSN X and they don't get
pushed. The push work then completes thinking it is done, and cannot
be restarted until the push target increases to >= X + 1. If the
push target then never increases (because the tail is not moving),
then we never run the push work again and we stall.

Fix it by making sure log items with a LSN that matches the target
exactly are pushed during the loop.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-05-09 12:17:04 -05:00
Dave Chinner
ea35a20021 xfs: exit AIL push work correctly when AIL is empty
The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. The main cause is a
regression where a work exit path fails to clear the PUSHING state
and recheck the target correctly.

Make both exit paths do the same PUSHING bit clearing and target
checking when the "no more work to be done" condition is hit.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-05-09 12:17:03 -05:00
Dave Chinner
b223221956 xfs: ensure reclaim cursor is reset correctly at end of AG
On a 32 bit highmem PowerPC machine, the XFS inode cache was growing
without bound and exhausting low memory causing the OOM killer to be
triggered. After some effort, the problem was reproduced on a 32 bit
x86 highmem machine.

The problem is that the per-ag inode reclaim index cursor was not
getting reset to the start of the AG if the radix tree tag lookup
found no more reclaimable inodes. Hence every further reclaim
attempt started at the same index beyond where any reclaimable
inodes lay, and no further background reclaim ever occurred from the
AG.

Without background inode reclaim the VM driven cache shrinker
simply cannot keep up with cache growth, and OOM is the result.

While the change that exposed the problem was the conversion of the
inode reclaim to use work queues for background reclaim, it was not
the cause of the bug. The bug was introduced when the cursor code
was added, just waiting for some weird configuration to strike....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-By: Christian Kujau <lists@nerdbynature.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-05-09 12:17:03 -05:00
Christoph Hellwig
8c1fdd0be5 xfs: add an x86 compat handler for XFS_IOC_ZERO_RANGE
XFS_IOC_ZERO_RANGE uses struct xfs_flock64, and thus requires argument
translation for 32-bit binaries on x86.  Add the required
XFS_IOC_ZERO_RANGE_32 defined and add it to the list of commands that
require xfs_flock64 translation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-28 13:27:46 -05:00
Christoph Hellwig
1a18a29478 xfs: fix compiler warning in xfs_trace.h
xfs_fsblock_t may be a 32-bit type on if XFS_BIG_BLKNOS is not set,
make sure to cast a value of this type to an unsigned long long
before using the ll printk qualifier.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-28 13:27:06 -05:00
David Sterba
45c51b9994 xfs: cleanup duplicate initializations
follow these guidelines:
- leave initialization in the declaration block if it fits the line
- move to the code where it's more suitable ('for' init block)

The last chunk was modified from David's original to be a correct
fix for what appeared to be a duplicate initialization.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2011-04-28 13:25:29 -05:00
Christoph Hellwig
8a072a4d4c xfs: reduce the number of pagb_lock roundtrips in xfs_alloc_clear_busy
Instead of finding the per-ag and then taking and releasing the pagb_lock
for every single busy extent completed sort the list of busy extents and
only switch betweens AGs where nessecary.  This becomes especially important
with the online discard support which will hit this lock more often.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-28 13:18:09 -05:00
Christoph Hellwig
97d3ac75e5 xfs: exact busy extent tracking
Update the extent tree in case we have to reuse a busy extent, so that it
always is kept uptodate.  This is done by replacing the busy list searches
with a new xfs_alloc_busy_reuse helper, which updates the busy extent tree
in case of a reuse.  This allows us to allow reusing metadata extents
unconditionally, and thus avoid log forces especially for allocation btree
blocks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-28 13:18:04 -05:00
Christoph Hellwig
e26f0501cf xfs: do not immediately reuse busy extent ranges
Every time we reallocate a busy extent, we cause a synchronous log force
to occur to ensure the freeing transaction is on disk before we continue
and use the newly allocated extent.  This is extremely sub-optimal as we
have to mark every transaction with blocks that get reused as synchronous.

Instead of searching the busy extent list after deciding on the extent to
allocate, check each candidate extent during the allocation decisions as
to whether they are in the busy list.  If they are in the busy list, we
trim the busy range out of the extent we have found and determine if that
trimmed range is still OK for allocation. In many cases, this check can
be incorporated into the allocation extent alignment code which already
does trimming of the found extent before determining if it is a valid
candidate for allocation.

Based on earlier patches from Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-28 13:18:01 -05:00
Christoph Hellwig
a870acd9b2 xfs: optimize AGFL refills
While we need to make sure we do not reuse busy extents, there is no need
to force out busy extents when moving them between the AGFL and the
freespace btree as we still take care of that when doing the real allocation.

To avoid the log force when just moving extents from the different free
space tracking structures, move the busy search out of
xfs_alloc_get_freelist into the callers that need it, and move the busy
list insert from xfs_free_ag_extent which is used both by AGFL refills
and real allocation to xfs_free_extent, which is only used by the latter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-28 13:17:56 -05:00
Dave Chinner
3eff126899 xfs: fix duplicate message output
Commit 957935dc ("xfs: fix xfs_debug warnings" broke the logic in
__xfs_printk(). Instead of only printing one of two possible output
strings based on whether the fs has a name or not, it outputs both.
Fix it to only output one message again.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-20 11:36:49 -05:00
Linus Torvalds
1e05ff020f Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: use proper interfaces for on-stack plugging
  xfs: fix xfs_debug warnings
  xfs: fix variable set but not used warnings
  xfs: convert log tail checking to a warning
  xfs: catch bad block numbers freeing extents.
  xfs: push the AIL from memory reclaim and periodic sync
  xfs: clean up code layout in xfs_trans_ail.c
  xfs: convert the xfsaild threads to a workqueue
  xfs: introduce background inode reclaim work
  xfs: convert ENOSPC inode flushing to use new syncd workqueue
  xfs: introduce a xfssyncd workqueue
  xfs: fix extent format buffer allocation size
  xfs: fix unreferenced var error in xfs_buf.c

Also, applied patch from Tony Luck that fixes ia64:
  xfs_destroy_workqueues() should not be tagged with__exit
in the branch before merging.
2011-04-11 15:48:57 -07:00
Luck, Tony
39411f81ee xfs_destroy_workqueues() should not be tagged with__exit
ia64 throws away .exit sections for the built-in CONFIG case, so routines
that are used in other circumstances should not be tagged as __exit.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-11 15:47:20 -07:00
Christoph Hellwig
a1b7ea5d58 xfs: use proper interfaces for on-stack plugging
Add proper blk_start_plug/blk_finish_plug pairs for the two places where
we issue buffer I/O, and remove the blk_flush_plug in xfs_buf_lock and
xfs_buf_iowait, given that context switches already flush the per-process
plugging lists.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-08 08:09:28 -05:00