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* xfs: remove subdirectoriesChristoph Hellwig2011-08-121-1065/+0
| | | | | | | | | | | | Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the annoying subdirectories in the XFS source code. Besides the large amount of file rename the only changes are to the Makefile, a few files including headers with the subdirectory prefix, and the binary sysctl compat code that includes a header under fs/xfs/ from kernel/. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* Merge branch 'master' of ↵Alex Elder2011-08-081-44/+27
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
| * Merge branch 'for-linus' of ↵Linus Torvalds2011-07-221-44/+27
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits) vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp isofs: Remove global fs lock jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory fix IN_DELETE_SELF on overwriting rename() on ramfs et.al. mm/truncate.c: fix build for CONFIG_BLOCK not enabled fs:update the NOTE of the file_operations structure Remove dead code in dget_parent() AFS: Fix silly characters in a comment switch d_add_ci() to d_splice_alias() in "found negative" case as well simplify gfs2_lookup() jfs_lookup(): don't bother with . or .. get rid of useless dget_parent() in btrfs rename() and link() get rid of useless dget_parent() in fs/btrfs/ioctl.c fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers drivers: fix up various ->llseek() implementations fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek Ext4: handle SEEK_HOLE/SEEK_DATA generically Btrfs: implement our own ->llseek fs: add SEEK_HOLE and SEEK_DATA flags reiserfs: make reiserfs default to barrier=flush ... Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new shrinker callout for the inode cache, that clashed with the xfs code to start the periodic workers later.
| | * xfs: make use of new shrinker callout for the inode cacheDave Chinner2011-07-201-44/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the inode reclaim shrinker to use the new per-sb shrinker operations. This allows much bigger reclaim batches to be used, and allows the XFS inode cache to be shrunk in proportion with the VFS dentry and inode caches. This avoids the problem of the VFS caches being shrunk significantly before the XFS inode cache is shrunk resulting in imbalances in the caches during reclaim. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | Replace the macro XFS_BUF_ISPINNED with helper xfs_buf_ispinnedChandra Seetharaman2011-07-251-1/+1
|/ / | | | | | | | | | | | | | | | | Replace the macro XFS_BUF_ISPINNED with an inline helper function xfs_buf_ispinned, and change all its usages. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* | xfs: Remove the second parameter to xfs_sb_count()Chandra Seetharaman2011-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | Remove the second parameter to xfs_sb_count() since all callers of the function set them. Also, fix the header comment regarding it being called periodically. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alex Elder <aelder@sgi.com>
* | xfs: improve sync behaviour in the face of aggressive dirtyingChristoph Hellwig2011-07-081-5/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following script from Wu Fengguang shows very bad behaviour in XFS when aggressively dirtying data during a sync on XFS, with sync times up to almost 10 times as long as ext4. A large part of the issue is that XFS writes data out itself two times in the ->sync_fs method, overriding the livelock protection in the core writeback code, and another issue is the lock-less xfs_ioend_wait call, which doesn't prevent new ioend from being queue up while waiting for the count to reach zero. This patch removes the XFS-internal sync calls and relies on the VFS to do it's work just like all other filesystems do. Note that the i_iocount wait which is rather suboptimal is simply removed here. We already do it in ->write_inode, which keeps the current supoptimal behaviour. We'll eventually need to remove that as well, but that's material for a separate commit. ------------------------------ snip ------------------------------ #!/bin/sh umount /dev/sda7 mkfs.xfs -f /dev/sda7 # mkfs.ext4 /dev/sda7 # mkfs.btrfs /dev/sda7 mount /dev/sda7 /fs echo $((50<<20)) > /proc/sys/vm/dirty_bytes pid= for i in `seq 10` do dd if=/dev/zero of=/fs/zero-$i bs=1M count=1000 & pid="$pid $!" done sleep 1 tic=$(date +'%s') sync tac=$(date +'%s') echo echo sync time: $((tac-tic)) egrep '(Dirty|Writeback|NFS_Unstable)' /proc/meminfo pidof dd > /dev/null && { kill -9 $pid; echo sync NOT livelocked; } ------------------------------ snip ------------------------------ Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
* vmscan: change shrinker API by passing shrink_control structYing Han2011-05-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* xfs: avoid getting stuck during async inode flushesDave Chinner2011-05-191-0/+10
| | | | | | | | | | | | | | | | | 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>
* xfs: ensure reclaim cursor is reset correctly at end of AGDave Chinner2011-05-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds2011-04-111-112/+116
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * '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.
| * xfs: push the AIL from memory reclaim and periodic syncDave Chinner2011-04-081-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we are short on memory, we want to expedite the cleaning of dirty objects. Hence when we run short on memory, we need to kick the AIL flushing into action to clean as many dirty objects as quickly as possible. To implement this, sample the lsn of the log item at the head of the AIL and use that as the push target for the AIL flush. Further, we keep items in the AIL that are dirty that are not tracked any other way, so we can get objects sitting in the AIL that don't get written back until the AIL is pushed. Hence to get the filesystem to the idle state, we might need to push the AIL to flush out any remaining dirty objects sitting in the AIL. This requires the same push mechanism as the reclaim push. This patch also renames xfs_trans_ail_tail() to xfs_ail_min_lsn() to match the new xfs_ail_max_lsn() function introduced in this patch. Similarly for xfs_trans_ail_push -> xfs_ail_push. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com>
| * xfs: introduce background inode reclaim workDave Chinner2011-04-081-3/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Background inode reclaim needs to run more frequently that the XFS syncd work is run as 30s is too long between optimal reclaim runs. Add a new periodic work item to the xfs syncd workqueue to run a fast, non-blocking inode reclaim scan. Background inode reclaim is kicked by the act of marking inodes for reclaim. When an AG is first marked as having reclaimable inodes, the background reclaim work is kicked. It will continue to run periodically untill it detects that there are no more reclaimable inodes. It will be kicked again when the first inode is queued for reclaim. To ensure shrinker based inode reclaim throttles to the inode cleaning and reclaim rate but still reclaim inodes efficiently, make it kick the background inode reclaim so that when we are low on memory we are trying to reclaim inodes as efficiently as possible. This kick shoul d not be necessary, but it will protect against failures to kick the background reclaim when inodes are first dirtied. To provide the rate throttling, make the shrinker pass do synchronous inode reclaim so that it blocks on inodes under IO. This means that the shrinker will reclaim inodes rather than just skipping over them, but it does not adversely affect the rate of reclaim because most dirty inodes are already under IO due to the background reclaim work the shrinker kicked. These two modifications solve one of the two OOM killer invocations Chris Mason reported recently when running a stress testing script. The particular workload trigger for the OOM killer invocation is where there are more threads than CPUs all unlinking files in an extremely memory constrained environment. Unlike other solutions, this one does not have a performance impact on performance when memory is not constrained or the number of concurrent threads operating is <= to the number of CPUs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * xfs: convert ENOSPC inode flushing to use new syncd workqueueDave Chinner2011-04-081-97/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On of the problems with the current inode flush at ENOSPC is that we queue a flush per ENOSPC event, regardless of how many are already queued. Thi can result in hundreds of queued flushes, most of which simply burn CPU scanned and do no real work. This simply slows down allocation at ENOSPC. We really only need one active flush at a time, and we can easily implement that via the new xfs_syncd_wq. All we need to do is queue a flush if one is not already active, then block waiting for the currently active flush to complete. The result is that we only ever have a single ENOSPC inode flush active at a time and this greatly reduces the overhead of ENOSPC processing. On my 2p test machine, this results in tests exercising ENOSPC conditions running significantly faster - 042 halves execution time, 083 drops from 60s to 5s, etc - while not introducing test regressions. This allows us to remove the old xfssyncd threads and infrastructure as they are no longer used. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * xfs: introduce a xfssyncd workqueueDave Chinner2011-04-081-45/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All of the work xfssyncd does is background functionality. There is no need for a thread per filesystem to do this work - it can al be managed by a global workqueue now they manage concurrency effectively. Introduce a new gglobal xfssyncd workqueue, and convert the periodic work to use this new functionality. To do this, use a delayed work construct to schedule the next running of the periodic sync work for the filesystem. When the sync work is complete, queue a new delayed work for the next running of the sync work. For laptop mode, we wait on completion for the sync works, so ensure that the sync work queuing interface can flush and wait for work to complete to enable the work queue infrastructure to replace the current sequence number and wakeup that is used. Because the sync work does non-trivial amounts of work, mark the new work queue as CPU intensive. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
* | Fix common misspellingsLucas De Marchi2011-03-311-1/+1
|/ | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* xfs: introduce inode cluster buffer trylocks for xfs_iflushDave Chinner2011-03-261-3/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | There is an ABBA deadlock between synchronous inode flushing in xfs_reclaim_inode and xfs_icluster_free. xfs_icluster_free locks the buffer, then takes inode ilocks, whilst synchronous reclaim takes the ilock followed by the buffer lock in xfs_iflush(). To avoid this deadlock, separate the inode cluster buffer locking semantics from the synchronous inode flush semantics, allowing callers to attempt to lock the buffer but still issue synchronous IO if it can get the buffer. This requires xfs_iflush() calls that currently use non-blocking semantics to pass SYNC_TRYLOCK rather than 0 as the flags parameter. This allows xfs_reclaim_inode to avoid the deadlock on the buffer lock and detect the failure so that it can drop the inode ilock and restart the reclaim attempt on the inode. This allows xfs_ifree_cluster to obtain the inode lock, mark the inode stale and release it and hence defuse the deadlock situation. It also has the pleasant side effect of avoiding IO in xfs_reclaim_inode when it tries to next reclaim the inode as it is now marked stale. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: Convert linux-2.6/ files to new logging interfaceDave Chinner2011-03-071-3/+2
| | | | | | | | | | | Convert the files in fs/xfs/linux-2.6/ to use the new xfs_<level> logging format that replaces the old Irix inherited cmn_err() interfaces. While there, also convert naked printk calls to use the relevant xfs logging function to standardise output format. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: ensure log covering transactions are synchronousDave Chinner2011-01-111-5/+6
| | | | | | | | | | | | | | | | | | To ensure the log is covered and the filesystem idles correctly, we need to ensure that dummy transactions hit the disk and do not stay pinned in memory. If the superblock is pinned in memory, it can't be flushed so the log covering cannot make progress. The result is dependent on timing - more oftent han not we continue to issues a log covering transaction every 36s rather than idling after ~90s. Fix this by making the log covering transaction synchronous. To avoid additional log force from xfssyncd, make the log covering transaction take the place of the existing log force in the xfssyncd background sync process. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: convert pag_ici_lock to a spin lockDave Chinner2010-12-161-4/+4
| | | | | | | | | | | | now that we are using RCU protection for the inode cache lookups, the lock is only needed on the modification side. Hence it is not necessary for the lock to be a rwlock as there are no read side holders anymore. Convert it to a spin lock to reflect it's exclusive nature. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: convert inode cache lookups to use RCU lockingDave Chinner2010-12-171-18/+66
| | | | | | | | | | | | | | | | | | | | | With delayed logging greatly increasing the sustained parallelism of inode operations, the inode cache locking is showing significant read vs write contention when inode reclaim runs at the same time as lookups. There is also a lot more write lock acquistions than there are read locks (4:1 ratio) so the read locking is not really buying us much in the way of parallelism. To avoid the read vs write contention, change the cache to use RCU locking on the read side. To avoid needing to RCU free every single inode, use the built in slab RCU freeing mechanism. This requires us to be able to detect lookups of freed inodes, so enѕure that ever freed inode has an inode number of zero and the XFS_IRECLAIM flag set. We already check the XFS_IRECLAIM flag in cache hit lookup path, but also add a check for a zero inode number as well. We canthen convert all the read locking lockups to use RCU read side locking and hence remove all read side locking. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: fix per-ag reference counting in inode reclaim tree walkingDave Chinner2010-11-101-0/+1
| | | | | | | | | | The walk fails to decrement the per-ag reference count when the non-blocking walk fails to obtain the per-ag reclaim lock, leading to an assert failure on debug kernels when unmounting a filesystem. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: serialise inode reclaim within an AGDave Chinner2010-10-181-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | Memory reclaim via shrinkers has a terrible habit of having N+M concurrent shrinker executions (N = num CPUs, M = num kswapds) all trying to shrink the same cache. When the cache they are all working on is protected by a single spinlock, massive contention an slowdowns occur. Wrap the per-ag inode caches with a reclaim mutex to serialise reclaim access to the AG. This will block concurrent reclaim in each AG but still allow reclaim to scan multiple AGs concurrently. Allow shrinkers to move on to the next AG if it can't get the lock, and if we can't get any AG, then start blocking on locks. To prevent reclaimers from continually scanning the same inodes in each AG, add a cursor that tracks where the last reclaim got up to and start from that point on the next reclaim. This should avoid only ever scanning a small number of inodes at the satart of each AG and not making progress. If we have a non-shrinker based reclaim pass, ignore the cursor and reset it to zero once we are done. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: batch inode reclaim lookupDave Chinner2010-10-181-33/+77
| | | | | | | | | | | | | | | Batch and optimise the per-ag inode lookup for reclaim to minimise scanning overhead. This involves gang lookups on the radix trees to get multiple inodes during each tree walk, and tighter validation of what inodes can be reclaimed without blocking befor we take any locks. This is based on ideas suggested in a proof-of-concept patch posted by Nick Piggin. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: implement batched inode lookups for AG walkingDave Chinner2010-10-181-22/+44
| | | | | | | | | | | | | With the reclaim code separated from the generic walking code, it is simple to implement batched lookups for the generic walk code. Separate out the inode validation from the execute operations and modify the tree lookups to get a batch of inodes at a time. Reclaim operations will be optimised separately. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: split out inode walk inode grabbingDave Chinner2010-10-181-45/+34
| | | | | | | | | | | | When doing read side inode cache walks, the code to validate and grab an inode is common to all callers. Split it out of the execute callbacks in preparation for batching lookups. Similarly, split out the inode reference dropping from the execute callbacks into the main lookup look to be symmetric with the grab. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: split inode AG walking into separate code for reclaimDave Chinner2010-10-181-111/+91
| | | | | | | | | | The reclaim walk requires different locking and has a slightly different walk algorithm, so separate it out so that it can be optimised separately. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: lockless per-ag lookupsDave Chinner2010-10-181-3/+3
| | | | | | | | | | | | | | | | | | | When we start taking a reference to the per-ag for every cached buffer in the system, kernel lockstat profiling on an 8-way create workload shows the mp->m_perag_lock has higher acquisition rates than the inode lock and has significantly more contention. That is, it becomes the highest contended lock in the system. The perag lookup is trivial to convert to lock-less RCU lookups because perag structures never go away. Hence the only thing we need to protect against is tree structure changes during a grow. This can be done simply by replacing the locking in xfs_perag_get() with RCU read locking. This removes the mp->m_perag_lock completely from this path. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
* xfs: properly account for reclaimed inodesJohannes Weiner2010-10-061-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When marking an inode reclaimable, a per-AG counter is increased, the inode is tagged reclaimable in its per-AG tree, and, when this is the first reclaimable inode in the AG, the AG entry in the per-mount tree is also tagged. When an inode is finally reclaimed, however, it is only deleted from the per-AG tree. Neither the counter is decreased, nor is the parent tree's AG entry untagged properly. Since the tags in the per-mount tree are not cleared, the inode shrinker iterates over all AGs that have had reclaimable inodes at one point in time. The counters on the other hand signal an increasing amount of slab objects to reclaim. Since "70e60ce xfs: convert inode shrinker to per-filesystem context" this is not a real issue anymore because the shrinker bails out after one iteration. But the problem was observable on a machine running v2.6.34, where the reclaimable work increased and each process going into direct reclaim eventually got stuck on the xfs inode shrinking path, trying to scan several million objects. Fix this by properly unwinding the reclaimable-state tracking of an inode when it is reclaimed. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: stable@kernel.org Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: dummy transactions should not dirty VFS stateDave Chinner2010-08-241-36/+6
| | | | | | | | | | | | | | | | | | | | | | | When we need to cover the log, we issue dummy transactions to ensure the current log tail is on disk. Unfortunately we currently use the root inode in the dummy transaction, and the act of committing the transaction dirties the inode at the VFS level. As a result, the VFS writeback of the dirty inode will prevent the filesystem from idling long enough for the log covering state machine to complete. The state machine gets stuck in a loop issuing new dummy transactions to cover the log and never makes progress. To avoid this problem, the dummy transactions should not cause externally visible state changes. To ensure this occurs, make sure that dummy transactions log an unchanging field in the superblock as it's state is never propagated outside the filesystem. This allows the log covering state machine to complete successfully and the filesystem now correctly enters a fully idle state about 90s after the last modification was made. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: simplify and remove xfs_ireclaimDave Chinner2010-07-261-1/+30
| | | | | | | | | | | | | | | | | xfs_ireclaim has to get and put te pag structure because it is only called with the inode to reclaim. The one caller of this function already has a reference on the pag and a pointer to is, so move the radix tree delete to the caller and remove xfs_ireclaim completely. This avoids a xfs_perag_get/put on every inode being reclaimed. The overhead was noticed in a bug report at: https://bugzilla.kernel.org/show_bug.cgi?id=16348 Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
* xfs: remove explicit xfs_sync_data/xfs_sync_attr calls on umountChristoph Hellwig2010-07-261-2/+2
| | | | | | | | | | On the final put of a superblock the VFS already calls sync_filesystem for us to write out all data and wait for it. No need to start another asynchronous writeback inside ->put_super. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com>
* xfs: simplify inode to transaction joiningChristoph Hellwig2010-07-261-2/+1
| | | | | | | | | | | | | | | | Currently we need to either call IHOLD or xfs_trans_ihold on an inode when joining it to a transaction via xfs_trans_ijoin. This patches instead makes xfs_trans_ijoin usable on it's own by doing an implicity xfs_trans_ihold, which also allows us to drop the third argument. For the case where we want to hold a reference on the inode a xfs_trans_ijoin_ref wrapper is added which does the IHOLD and marks the inode for needing an xfs_iput. In addition to the cleaner interface to the caller this also simplifies the implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com>
* xfs: remove unneeded #include statementsChristoph Hellwig2010-07-261-10/+0
| | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
* xfs: drop dmapi hooksChristoph Hellwig2010-07-261-1/+0
| | | | | | | | | | | | | | Dmapi support was never merged upstream, but we still have a lot of hooks bloating XFS for it, all over the fast pathes of the filesystem. This patch drops over 700 lines of dmapi overhead. If we'll ever get HSM support in mainline at least the namespace events can be done much saner in the VFS instead of the individual filesystem, so it's not like this is much help for future work. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com>
* xfs: track AGs with reclaimable inodes in per-ag radix treeDave Chinner2010-07-201-7/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | https://bugzilla.kernel.org/show_bug.cgi?id=16348 When the filesystem grows to a large number of allocation groups, the summing of recalimable inodes gets expensive. In many cases, most AGs won't have any reclaimable inodes and so we are wasting CPU time aggregating over these AGs. This is particularly important for the inode shrinker that gets called frequently under memory pressure. To avoid the overhead, track AGs with reclaimable inodes in the per-ag radix tree so that we can find all the AGs with reclaimable inodes via a simple gang tag lookup. This involves setting the tag when the first reclaimable inode is tracked in the AG, and removing the tag when the last reclaimable inode is removed from the tree. Then the summation process becomes a loop walking the radix tree summing AGs with the reclaim tag set. This significantly reduces the overhead of scanning - a 6400 AG filesystea now only uses about 25% of a cpu in kswapd while slab reclaim progresses instead of being permanently stuck at 100% CPU and making little progress. Clean filesystems filesystems will see no overhead and the overhead only increases linearly with the number of dirty AGs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: convert inode shrinker to per-filesystem contextsDave Chinner2010-07-201-48/+14
| | | | | | | | | | | | Now the shrinker passes us a context, wire up a shrinker context per filesystem. This allows us to remove the global mount list and the locking problems that introduced. It also means that a shrinker call does not need to traverse clean filesystems before finding a filesystem with reclaimable inodes. This significantly reduces scanning overhead when lots of filesystems are present. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* mm: add context argument to shrinker callbackDave Chinner2010-07-191-0/+1
| | | | | | | | | | | | The current shrinker implementation requires the registered callback to have global state to work from. This makes it difficult to shrink caches that are not global (e.g. per-filesystem caches). Pass the shrinker structure to the callback so that users can embed the shrinker structure in the context the shrinker needs to operate on and get back to it in the callback via container_of(). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: fix access to upper inodes without inode64Christoph Hellwig2010-05-281-9/+0
| | | | | | | | | | | | | | If a filesystem is mounted without the inode64 mount option we should still be able to access inodes not fitting into 32 bits, just not created new ones. For this to work we need to make sure the inode cache radix tree is initialized for all allocation groups, not just those we plan to allocate inodes from. This patch makes sure we initialize the inode cache radix tree for all allocation groups, and also cleans xfs_initialize_perag up a bit to separate the inode32 logical from the general perag structure setup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: enforce synchronous writes in xfs_bwriteChristoph Hellwig2010-05-191-1/+0
| | | | | | | | | | | | | xfs_bwrite is used with the intention of synchronously writing out buffers, but currently it does not actually clear the async flag if that's left from previous writes but instead implements async behaviour if it finds it. Remove the code handling asynchronous writes as we've got rid of those entirely outside of the log and delwri buffers, and make sure that we clear the async and read flags before writing the buffer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: remove periodic superblock writebackChristoph Hellwig2010-05-191-63/+27
| | | | | | | | | | | | | | All modifications to the superblock are done transactional through xfs_trans_log_buf, so there is no reason to initiate periodic asynchronous writeback. This only removes the superblock from the delwri list and will lead to sub-optimal I/O scheduling. Cut down xfs_sync_fsdata now that it's only used for synchronous superblock writes and move the log coverage checks into the two callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: add blockdev name to kthreadsJan Engelhardt2010-05-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | This allows to see in `ps` and similar tools which kthreads are allotted to which block device/filesystem, similar to what jbd2 does. As the process name is a fixed 16-char array, no extra space is needed in tasks. PID TTY STAT TIME COMMAND 2 ? S 0:00 [kthreadd] 197 ? S 0:00 \_ [jbd2/sda2-8] 198 ? S 0:00 \_ [ext4-dio-unwrit] 204 ? S 0:00 \_ [flush-8:0] 2647 ? S 0:00 \_ [xfs_mru_cache] 2648 ? S 0:00 \_ [xfslogd/0] 2649 ? S 0:00 \_ [xfsdatad/0] 2650 ? S 0:00 \_ [xfsconvertd/0] 2651 ? S 0:00 \_ [xfsbufd/ram0] 2652 ? S 0:00 \_ [xfsaild/ram0] 2653 ? S 0:00 \_ [xfssyncd/ram0] Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Reviewed-by: Dave Chinner <david@fromorbit.com>
* xfs: add a shrinker to background inode reclaimDave Chinner2010-04-291-7/+105
| | | | | | | | | | | | | | On low memory boxes or those with highmem, kernel can OOM before the background reclaims inodes via xfssyncd. Add a shrinker to run inode reclaim so that it inode reclaim is expedited when memory is low. This is more complex than it needs to be because the VM folk don't want a context added to the shrinker infrastructure. Hence we need to add a global list of XFS mount structures so the shrinker can traverse them. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: don't warn on EAGAIN in inode reclaimDave Chinner2010-04-161-2/+2
| | | | | | | | | | Any inode reclaim flush that returns EAGAIN will result in the inode reclaim being attempted again later. There is no need to issue a warning into the logs about this situation. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: check for more work before sleeping in xfssyncdDave Chinner2010-03-051-3/+3
| | | | | | | | | | | | | | | xfssyncd processes a queue of work by detaching the queue and then iterating over all the work items. It then sleeps for a time period or until new work comes in. If new work is queued while xfssyncd is actively processing the detached work queue, it will not process that new work until after a sleep timeout or the next work event queued wakes it. Fix this by checking the work queue again before going to sleep. Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: fix locking for inode cache radix tree tag updatesChristoph Hellwig2010-03-011-2/+2
| | | | | | | | | | | | | | The radix-tree code requires it's users to serialize tag updates against other updates to the tree. While XFS protects tag updates against each other it does not serialize them against updates of the tree contents, which can lead to tag corruption. Fix the inode cache to always take pag_ici_lock in exclusive mode when updating radix tree tags. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Patrick Schreurs <patrick@news-service.com> Tested-by: Patrick Schreurs <patrick@news-service.com> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: Use delayed write for inodes rather than async V2Dave Chinner2010-02-061-29/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently do background inode flush asynchronously, resulting in inodes being written in whatever order the background writeback issues them. Not only that, there are also blocking and non-blocking asynchronous inode flushes, depending on where the flush comes from. This patch completely removes asynchronous inode writeback. It removes all the strange writeback modes and replaces them with either a synchronous flush or a non-blocking delayed write flush. That is, inode flushes will only issue IO directly if they are synchronous, and background flushing may do nothing if the operation would block (e.g. on a pinned inode or buffer lock). Delayed write flushes will now result in the inode buffer sitting in the delwri queue of the buffer cache to be flushed by either an AIL push or by the xfsbufd timing out the buffer. This will allow accumulation of dirty inode buffers in memory and allow optimisation of inode cluster writeback at the xfsbufd level where we have much greater queue depths than the block layer elevators. We will also get adjacent inode cluster buffer IO merging for free when a later patch in the series allows sorting of the delayed write buffers before dispatch. This effectively means that any inode that is written back by background writeback will be seen as flush locked during AIL pushing, and will result in the buffers being pushed from there. This writeback path is currently non-optimal, but the next patch in the series will fix that problem. A side effect of this delayed write mechanism is that background inode reclaim will no longer directly flush inodes, nor can it wait on the flush lock. The result is that inode reclaim must leave the inode in the reclaimable state until it is clean. Hence attempts to reclaim a dirty inode in the background will simply skip the inode until it is clean and this allows other mechanisms (i.e. xfsbufd) to do more optimal writeback of the dirty buffers. As a result, the inode reclaim code has been rewritten so that it no longer relies on the ambiguous return values of xfs_iflush() to determine whether it is safe to reclaim an inode. Portions of this patch are derived from patches by Christoph Hellwig. Version 2: - cleanup reclaim code as suggested by Christoph - log background reclaim inode flush errors - just pass sync flags to xfs_iflush Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: Make inode reclaim states explicitDave Chinner2010-02-061-19/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | A.K.A.: don't rely on xfs_iflush() return value in reclaim We have gradually been moving checks out of the reclaim code because they are duplicated in xfs_iflush(). We've had a history of problems in this area, and many of them stem from the overloading of the return values from xfs_iflush() and interaction with inode flush locking to determine if the inode is safe to reclaim. With the desire to move to delayed write flushing of inodes and non-blocking inode tree reclaim walks, the overloading of the return value of xfs_iflush makes it very difficult to determine the correct thing to do next. This patch explicitly re-adds the checks to the inode reclaim code, removing the reliance on the return value of xfs_iflush() to determine what to do next. It also means that we can clearly document all the inode states that reclaim must handle and hence we can easily see that we handled all the necessary cases. This also removes the need for the xfs_inode_clean() check in xfs_iflush() as all callers now check this first (safely). Signed-off-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: cleanup up xfs_log_force calling conventionsChristoph Hellwig2010-01-211-12/+5
| | | | | | | | | | | | | | | | Remove the XFS_LOG_FORCE argument which was always set, and the XFS_LOG_URGE define, which was never used. Split xfs_log_force into a two helpers - xfs_log_force which forces the whole log, and xfs_log_force_lsn which forces up to the specified LSN. The underlying implementations already were entirely separate, as were the users. Also re-indent the new _xfs_log_force/_xfs_log_force which previously had a weird coding style. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: remove duplicate buffer flagsChristoph Hellwig2010-01-211-2/+2
| | | | | | | | | | | | | Currently we define aliases for the buffer flags in various namespaces, which only adds confusion. Remove all but the XBF_ flags to clean this up a bit. Note that we still abuse XFS_B_ASYNC/XBF_ASYNC for some non-buffer uses, but I'll clean that up later. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Alex Elder <aelder@sgi.com>
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