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2011-07-06xfs: unpin stale inodes directly in IOP_COMMITTEDDave Chinner
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>
2011-06-23xfs: prevent bogus assert when trying to remove non-existent attributeDave Chinner
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>
2011-06-23xfs: clear XFS_IDIRTY_RELEASE on truncate downDave Chinner
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>
2011-06-23xfs: reset inode per-lifetime state when recycling itDave Chinner
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>
2011-06-16xfs: make log devices with write back caches workChristoph Hellwig
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>
2011-06-14xfs: fix ->mknod() return value on xfs_get_acl() failureAl Viro
->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>
2011-05-27fs: pass exact type of data dirties to ->dirty_inodeChristoph Hellwig
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>
2011-05-26Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* '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
2011-05-25xfs: correctly decrement the extent buffer index in xfs_bmap_del_extentChristoph Hellwig
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>
2011-05-25xfs: check for valid indices in xfs_iext_get_ext and xfs_iext_idx_to_irecChristoph Hellwig
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>
2011-05-25xfs: fix up asserts in xfs_iflush_forkChristoph Hellwig
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>
2011-05-25xfs: do not do pointer arithmetic on extent recordsChristoph Hellwig
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>
2011-05-25xfs: do not use unchecked extent indices in xfs_bunmapiChristoph Hellwig
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>
2011-05-25xfs: do not use unchecked extent indices in xfs_bmapiChristoph Hellwig
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>
2011-05-25xfs: do not use unchecked extent indices in xfs_bmap_add_extent_*Christoph Hellwig
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>
2011-05-25xfs: remove if_lastexChristoph Hellwig
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>
2011-05-25xfs: remove the unused XFS_BMAPI_RSVBLOCKS flagChristoph Hellwig
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>
2011-05-25vmscan: change shrinker API by passing shrink_control structYing Han
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>
2011-05-24xfs: do not discard alloc btree blocksChristoph Hellwig
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>
2011-05-24xfs: add online discard supportChristoph Hellwig
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>
2011-05-23Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* '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
2011-05-23Merge branch 'for-linus' of ↵Linus Torvalds
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 ...
2011-05-19xfs: obey minleft values during extent allocation correctlyDave Chinner
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>
2011-05-19xfs: reset buffer pointers before freeing themDave Chinner
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>
2011-05-19xfs: avoid getting stuck during async inode flushesDave Chinner
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>
2011-05-19xfs: fix xfs_itruncate_start tracingDave Chinner
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>
2011-05-19xfs: fix duplicate workqueue initialisationDave Chinner
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>
2011-05-19xfs: kill off xfs_printk()Joe Perches
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>
2011-05-10treewide: fix a few typos in commentsJustin P. Mattock
- 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>
2011-05-09xfs: fix race condition in AIL push triggerDave Chinner
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 e4d3c4a43b595d5124ae824d300626e6489ae857)
2011-05-09xfs: make AIL target updates and compares 32bit safe.Dave Chinner
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 fd5670f22fce247754243cf2ed41941e5762d990)
2011-05-09xfs: always push the AIL to the targetDave Chinner
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 cb64026b6e8af50db598ec7c3f59d504259b00bb)
2011-05-09xfs: exit AIL push work correctly when AIL is emptyDave Chinner
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 ea35a20021f8497390d05b93271b4d675516c654)
2011-05-09xfs: ensure reclaim cursor is reset correctly at end of AGDave Chinner
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 b223221956675ce8a7b436d198ced974bb388571)
2011-05-09xfs: fix race condition in AIL push triggerDave Chinner
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>
2011-05-09xfs: make AIL target updates and compares 32bit safe.Dave Chinner
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>
2011-05-09xfs: always push the AIL to the targetDave Chinner
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>
2011-05-09xfs: exit AIL push work correctly when AIL is emptyDave Chinner
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>
2011-05-09xfs: ensure reclaim cursor is reset correctly at end of AGDave Chinner
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>
2011-04-28xfs: add an x86 compat handler for XFS_IOC_ZERO_RANGEChristoph Hellwig
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>
2011-04-28xfs: fix compiler warning in xfs_trace.hChristoph Hellwig
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>
2011-04-28xfs: cleanup duplicate initializationsDavid Sterba
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>
2011-04-28xfs: reduce the number of pagb_lock roundtrips in xfs_alloc_clear_busyChristoph Hellwig
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>
2011-04-28xfs: exact busy extent trackingChristoph Hellwig
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>
2011-04-28xfs: do not immediately reuse busy extent rangesChristoph Hellwig
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>
2011-04-28xfs: optimize AGFL refillsChristoph Hellwig
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>
2011-04-20xfs: fix duplicate message outputDave Chinner
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>
2011-04-11Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* '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.
2011-04-11xfs_destroy_workqueues() should not be tagged with__exitLuck, Tony
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>
2011-04-08xfs: use proper interfaces for on-stack pluggingChristoph Hellwig
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>