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2010-10-22Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds60-1375/+1185
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (36 commits) xfs: semaphore cleanup xfs: Extend project quotas to support 32bit project ids xfs: remove xfs_buf wrappers xfs: remove xfs_cred.h xfs: remove xfs_globals.h xfs: remove xfs_version.h xfs: remove xfs_refcache.h xfs: fix the xfs_trans_committed xfs: remove unused t_callback field in struct xfs_trans xfs: fix bogus m_maxagi check in xfs_iget xfs: do not use xfs_mod_incore_sb_batch for per-cpu counters xfs: do not use xfs_mod_incore_sb for per-cpu counters xfs: remove XFS_MOUNT_NO_PERCPU_SB xfs: pack xfs_buf structure more tightly xfs: convert buffer cache hash to rbtree xfs: serialise inode reclaim within an AG xfs: batch inode reclaim lookup xfs: implement batched inode lookups for AG walking xfs: split out inode walk inode grabbing xfs: split inode AG walking into separate code for reclaim ...
2010-10-22Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-1/+1
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: remove in_workqueue_context() workqueue: Clarify that schedule_on_each_cpu is synchronous memory_hotplug: drop spurious calls to flush_scheduled_work() shpchp: update workqueue usage pciehp: update workqueue usage isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr() workqueue: add and use WQ_MEM_RECLAIM flag workqueue: fix HIGHPRI handling in keep_working() workqueue: add queue_work and activate_work trace points workqueue: prepare for more tracepoints workqueue: implement flush[_delayed]_work_sync() workqueue: factor out start_flush_work() workqueue: cleanup flush/cancel functions workqueue: implement alloc_ordered_workqueue() Fix up trivial conflict in fs/gfs2/main.c as per Tejun
2010-10-19Merge branch 'v2.6.36-rc8' into for-2.6.37/barrierJens Axboe19-239/+332
Conflicts: block/blk-core.c drivers/block/loop.c mm/swapfile.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-18xfs: semaphore cleanupThomas Gleixner1-1/+1
Get rid of init_MUTEX[_LOCKED]() and use sema_init() instead. (Ported to current XFS code by <aelder@sgi.com>.) Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: Extend project quotas to support 32bit project idsArkadiusz Mi?kiewicz16-44/+80
This patch adds support for 32bit project quota identifiers. On disk format is backward compatible with 16bit projid numbers. projid on disk is now kept in two 16bit values - di_projid_lo (which holds the same position as old 16bit projid value) and new di_projid_hi (takes existing padding) and converts from/to 32bit value on the fly. xfs_admin (for existing fs), mkfs.xfs (for new fs) needs to be used to enable PROJID32BIT support. Signed-off-by: Arkadiusz Miśkiewicz <arekm@maven.pl> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove xfs_buf wrappersChristoph Hellwig16-48/+33
Stop having two different names for many buffer functions and use the more descriptive xfs_buf_* names directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove xfs_cred.hChristoph Hellwig12-58/+18
We're not actually passing around credentials inside XFS for a while now, so remove all xfs_cred.h with it's cred_t typedef and all instances of it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove xfs_globals.hChristoph Hellwig2-24/+0
This header only provides one extern that isn't actually declared anywhere, and shadowed by a macro. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove xfs_version.hChristoph Hellwig3-30/+1
It used to have a place when it contained an automatically generated CVS version, but these days it's entirely superflous. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove xfs_refcache.hChristoph Hellwig1-52/+0
This header has been completely unused for a couple of years. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: fix the xfs_trans_committedChristoph Hellwig1-2/+3
Use the correct prototype for xfs_trans_committed instead of casting it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove unused t_callback field in struct xfs_transChristoph Hellwig2-6/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: fix bogus m_maxagi check in xfs_igetChristoph Hellwig1-2/+2
These days inode64 should only control which AGs we allocate new inodes from, while we still try to support reading all existing inodes. To make this actually work the check ontop of xfs_iget needs to be relaxed to allow inodes in all allocation groups instead of just those that we allow allocating inodes from. Note that we can't simply remove the check - it prevents us from accessing invalid data when fed invalid inode numbers from NFS or bulkstat. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: do not use xfs_mod_incore_sb_batch for per-cpu countersChristoph Hellwig2-107/+85
Update the per-cpu counters manually in xfs_trans_unreserve_and_mod_sb and remove support for per-cpu counters from xfs_mod_incore_sb_batch to simplify it. And added benefit is that we don't have to take m_sb_lock for transactions that only modify per-cpu counters. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: do not use xfs_mod_incore_sb for per-cpu countersChristoph Hellwig5-40/+35
Export xfs_icsb_modify_counters and always use it for modifying the per-cpu counters. Remove support for per-cpu counters from xfs_mod_incore_sb to simplify it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove XFS_MOUNT_NO_PERCPU_SBChristoph Hellwig3-29/+19
Fail the mount if we can't allocate memory for the per-CPU counters. This is consistent with how we handle everything else in the mount path and makes the superblock counter modification a lot simpler. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: pack xfs_buf structure more tightlyDave Chinner1-11/+19
pahole reports the struct xfs_buf has quite a few holes in it, so packing the structure better will reduce the size of it by 16 bytes. Also, move all the fields used in cache lookups into the first cacheline. Before on x86_64: /* size: 320, cachelines: 5 */ /* sum members: 298, holes: 6, sum holes: 22 */ After on x86_64: /* size: 304, cachelines: 5 */ /* padding: 6 */ /* last cacheline: 48 bytes */ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: convert buffer cache hash to rbtreeDave Chinner4-76/+74
The buffer cache hash is showing typical hash scalability problems. In large scale testing the number of cached items growing far larger than the hash can efficiently handle. Hence we need to move to a self-scaling cache indexing mechanism. I have selected rbtrees for indexing becuse they can have O(log n) search scalability, and insert and remove cost is not excessive, even on large trees. Hence we should be able to cache large numbers of buffers without incurring the excessive cache miss search penalties that the hash is imposing on us. To ensure we still have parallel access to the cache, we need multiple trees. Rather than hashing the buffers by disk address to select a tree, it seems more sensible to separate trees by typical access patterns. Most operations use buffers from within a single AG at a time, so rather than searching lots of different lists, separate the buffer indexes out into per-AG rbtrees. This means that searches during metadata operation have a much higher chance of hitting cache resident nodes, and that updates of the tree are less likely to disturb trees being accessed on other CPUs doing independent operations. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: serialise inode reclaim within an AGDave Chinner3-0/+33
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>
2010-10-18xfs: batch inode reclaim lookupDave Chinner1-33/+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>
2010-10-18xfs: implement batched inode lookups for AG walkingDave Chinner2-23/+45
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>
2010-10-18xfs: split out inode walk inode grabbingDave Chinner2-54/+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>
2010-10-18xfs: split inode AG walking into separate code for reclaimDave Chinner6-115/+122
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>
2010-10-18xfs: remove buftarg hash for external devicesDave Chinner1-1/+5
For RT and external log devices, we never use hashed buffers on them now. Remove the buftarg hash tables that are set up for them. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: use unhashed buffers for size checksDave Chinner3-45/+34
When we are checking we can access the last block of each device, we do not need to use cached buffers as they will be tossed away immediately. Use uncached buffers for size checks so that all IO prior to full in-memory structure initialisation does not use the buffer cache. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: kill XBF_FS_MANAGED buffersDave Chinner3-59/+20
Filesystem level managed buffers are buffers that have their lifecycle controlled by the filesystem layer, not the buffer cache. We currently cache these buffers, which makes cleanup and cache walking somewhat troublesome. Convert the fs managed buffers to uncached buffers obtained by via xfs_buf_get_uncached(), and remove the XBF_FS_MANAGED special cases from the buffer cache. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: store xfs_mount in the buftarg instead of in the xfs_bufDave Chinner5-21/+20
Each buffer contains both a buftarg pointer and a mount pointer. If we add a mount pointer into the buftarg, we can avoid needing the b_mount field in every buffer and grab it from the buftarg when needed instead. This shrinks the xfs_buf by 8 bytes. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: introduced uncached buffer read primitveDave Chinner2-0/+37
To avoid the need to use cached buffers for single-shot or buffers cached at the filesystem level, introduce a new buffer read primitive that bypasses the cache an reads directly from disk. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: rename xfs_buf_get_nodaddr to be more appropriateDave Chinner6-11/+14
xfs_buf_get_nodaddr() is really used to allocate a buffer that is uncached. While it is not directly assigned a disk address, the fact that they are not cached is a more important distinction. With the upcoming uncached buffer read primitive, we should be consistent with this disctinction. While there, make page allocation in xfs_buf_get_nodaddr() safe against memory reclaim re-entrancy into the filesystem by allowing a flags parameter to be passed. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: don't use vfs writeback for pure metadata modificationsDave Chinner12-86/+65
Under heavy multi-way parallel create workloads, the VFS struggles to write back all the inodes that have been changed in age order. The bdi flusher thread becomes CPU bound, spending 85% of it's time in the VFS code, mostly traversing the superblock dirty inode list to separate dirty inodes old enough to flush. We already keep an index of all metadata changes in age order - in the AIL - and continued log pressure will do age ordered writeback without any extra overhead at all. If there is no pressure on the log, the xfssyncd will periodically write back metadata in ascending disk address offset order so will be very efficient. Hence we can stop marking VFS inodes dirty during transaction commit or when changing timestamps during transactions. This will keep the inodes in the superblock dirty list to those containing data or unlogged metadata changes. However, the timstamp changes are slightly more complex than this - there are a couple of places that do unlogged updates of the timestamps, and the VFS need to be informed of these. Hence add a new function xfs_trans_ichgtime() for transactional changes, and leave xfs_ichgtime() for the non-transactional changes. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-10-18xfs: lockless per-ag lookupsDave Chinner3-11/+23
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>
2010-10-18xfs: remove debug assert for per-ag reference countingDave Chinner1-2/+0
When we start taking references per cached buffer to the the perag it is cached on, it will blow the current debug maximum reference count assert out of the water. The assert has never caught a bug, and we have tracing to track changes if there ever is a problem, so just remove it. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: reduce the number of CIL lock round trips during commitDave Chinner1-105/+127
When commiting a transaction, we do a lock CIL state lock round trip on every single log vector we insert into the CIL. This is resulting in the lock being as hot as the inode and dcache locks on 8-way create workloads. Rework the insertion loops to bring the number of lock round trips to one per transaction for log vectors, and one more do the busy extents. Also change the allocation of the log vector buffer not to zero it as we copy over the entire allocated buffer anyway. This patch also includes a structural cleanup to the CIL item insertion provided by Christoph Hellwig. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: eliminate some newly-reported gcc warningsPoyo VL1-2/+2
Ionut Gabriel Popescu <poyo_vl@yahoo.com> submitted a simple change to eliminate some "may be used uninitialized" warnings when building XFS. The reported condition seems to be something that GCC did not used to recognize or report. The warnings were produced by: gcc version 4.5.0 20100604 [gcc-4_5-branch revision 160292] (SUSE Linux) Signed-off-by: Ionut Gabriel Popescu <poyo_vl@yahoo.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: remove the ->kill_root btree operationChristoph Hellwig4-88/+44
The implementation os ->kill_root only differ by either simply zeroing out the now unused buffer in the btree cursor in the inode allocation btree or using xfs_btree_setbuf in the allocation btree. Initially both of them used xfs_btree_setbuf, but the use in the ialloc btree was removed early on because it interacted badly with xfs_trans_binval. In addition to zeroing out the buffer in the cursor xfs_btree_setbuf updates the bc_ra array in the btree cursor, and calls xfs_trans_brelse on the buffer previous occupying the slot. The bc_ra update should be done for the alloc btree updated too, although the lack of it does not cause serious problems. The xfs_trans_brelse call on the other hand is effectively a no-op in the end - it keeps decrementing the bli_recur refcount until it hits zero, and then just skips out because the buffer will always be dirty at this point. So removing it for the allocation btree is just fine. So unify the code and move it to xfs_btree.c. While we're at it also replace the call to xfs_btree_setbuf with a NULL bp argument in xfs_btree_del_cursor with a direct call to xfs_trans_brelse given that the cursor is beeing freed just after this and the state updates are superflous. After this xfs_btree_setbuf is only used with a non-NULL bp argument and can thus be simplified. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: stop using xfs_qm_dqtobp in xfs_qm_dqflushChristoph Hellwig1-88/+76
In xfs_qm_dqflush we know that q_blkno must be initialized already from a previous xfs_qm_dqread. So instead of calling xfs_qm_dqtobp we can simply read the quota buffer directly. This also saves us from a duplicate xfs_qm_dqcheck call check and allows xfs_qm_dqtobp to be simplified now that it is always called for a newly initialized inode. In addition to that properly unwind all locks in xfs_qm_dqflush when xfs_qm_dqcheck fails. This mirrors a similar cleanup in the inode lookup done earlier. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: simplify xfs_qm_dqusage_adjustChristoph Hellwig1-142/+61
There is no need to have the users and group/project quota locked at the same time. Get rid of xfs_qm_dqget_noattach and just do a xfs_qm_dqget inside xfs_qm_quotacheck_dqadjust for the quota we are operating on right now. The new version of xfs_qm_quotacheck_dqadjust holds the inode lock over it's operations, which is not a problem as it simply increments counters and there is no concern about log contention during mount time. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18xfs: Introduce XFS_IOC_ZERO_RANGEDave Chinner6-9/+27
XFS_IOC_ZERO_RANGE is the equivalent of an atomic XFS_IOC_UNRESVSP/ XFS_IOC_RESVSP call pair. It enabled ranges of written data to be turned into zeroes without requiring IO or having to free and reallocate the extents in the range given as would occur if we had to punch and then preallocate them separately. This enables applications to zero parts of files very quickly without changing the layout of the files in any way. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-10-18xfs: use range primitives for xfs page cache operationsDave Chinner1-16/+15
While XFS passes ranges to operate on from the core code, the functions being called ignore the either the entire range or the end of the range. This is historical because when the function were written linux didn't have the necessary range operations. Update the functions to use the correct operations. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-10-11workqueue: add and use WQ_MEM_RECLAIM flagTejun Heo1-1/+1
Add WQ_MEM_RECLAIM flag which currently maps to WQ_RESCUER, mark WQ_RESCUER as internal and replace all external WQ_RESCUER usages to WQ_MEM_RECLAIM. This makes the API users express the intent of the workqueue instead of indicating the internal mechanism used to guarantee forward progress. This is also to make it cleaner to add more semantics to WQ_MEM_RECLAIM. For example, if deemed necessary, memory reclaim workqueues can be made highpri. This patch doesn't introduce any functional change. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Steven Whitehouse <swhiteho@redhat.com>
2010-10-06xfs: properly account for reclaimed inodesJohannes Weiner1-5/+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>
2010-09-29xfs: force background CIL push under sustained loadDave Chinner2-19/+30
I have been seeing occasional pauses in transaction throughput up to 30s long under heavy parallel workloads. The only notable thing was that the xfsaild was trying to be active during the pauses, but making no progress. It was running exactly 20 times a second (on the 50ms no-progress backoff), and the number of pushbuf events was constant across this time as well. IOWs, the xfsaild appeared to be stuck on buffers that it could not push out. Further investigation indicated that it was trying to push out inode buffers that were pinned and/or locked. The xfsbufd was also getting woken at the same frequency (by the xfsaild, no doubt) to push out delayed write buffers. The xfsbufd was not making any progress because all the buffers in the delwri queue were pinned. This scan- and-make-no-progress dance went one in the trace for some seconds, before the xfssyncd came along an issued a log force, and then things started going again. However, I noticed something strange about the log force - there were way too many IO's issued. 516 log buffers were written, to be exact. That added up to 129MB of log IO, which got me very interested because it's almost exactly 25% of the size of the log. He delayed logging code is suppose to aggregate the minimum of 25% of the log or 8MB worth of changes before flushing. That's what really puzzled me - why did a log force write 129MB instead of only 8MB? Essentially what has happened is that no CIL pushes had occurred since the previous tail push which cleared out 25% of the log space. That caused all the new transactions to block because there wasn't log space for them, but they kick the xfsaild to push the tail. However, the xfsaild was not making progress because there were buffers it could not lock and flush, and the xfsbufd could not flush them because they were pinned. As a result, both the xfsaild and the xfsbufd could not move the tail of the log forward without the CIL first committing. The cause of the problem was that the background CIL push, which should happen when 8MB of aggregated changes have been committed, is being held off by the concurrent transaction commit load. The background push does a down_write_trylock() which will fail if there is a concurrent transaction commit holding the push lock in read mode. With 8 CPUs all doing transactions as fast as they can, there was enough concurrent transaction commits to hold off the background push until tail-pushing could no longer free log space, and the halt would occur. It should be noted that there is no reason why it would halt at 25% of log space used by a single CIL checkpoint. This bug could definitely violate the "no transaction should be larger than half the log" requirement and hence result in corruption if the system crashed under heavy load. This sort of bug is exactly the reason why delayed logging was tagged as experimental.... The fix is to start blocking background pushes once the threshold has been exceeded. Rework the threshold calculations to keep the amount of log space a CIL checkpoint can use to below that of the AIL push threshold to avoid the problem completely. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-09-16block: remove BLKDEV_IFL_WAITChristoph Hellwig1-2/+1
All the blkdev_issue_* helpers can only sanely be used for synchronous caller. To issue cache flushes or barriers asynchronously the caller needs to set up a bio by itself with a completion callback to move the asynchronous state machine ahead. So drop the BLKDEV_IFL_WAIT flag that is always specified when calling blkdev_issue_* and also remove the now unused flags argument to blkdev_issue_flush and blkdev_issue_zeroout. For blkdev_issue_discard we need to keep it for the secure discard flag, which gains a more descriptive name and loses the bitops vs flag confusion. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10xfs: log IO completion workqueue is a high priority queueDave Chinner1-1/+2
The workqueue implementation in 2.6.36-rcX has changed, resulting in the workqueues no longer having dedicated threads for work processing. This has caused severe livelocks under heavy parallel create workloads because the log IO completions have been getting held up behind metadata IO completions. Hence log commits would stall, memory allocation would stall because pages could not be cleaned, and lock contention on the AIL during inode IO completion processing was being seen to slow everything down even further. By making the log Io completion workqueue a high priority workqueue, they are queued ahead of all data/metadata IO completions and processed before the data/metadata completions. Hence the log never gets stalled, and operations needed to clean memory can continue as quickly as possible. This avoids the livelock conditions and allos the system to keep running under heavy load as per normal. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-09-10xfs: prevent reading uninitialized stack memoryDan Rosenberg1-0/+2
The XFS_IOC_FSGETXATTR ioctl allows unprivileged users to read 12 bytes of uninitialized stack memory, because the fsxattr struct declared on the stack in xfs_ioc_fsgetxattr() does not alter (or zero) the 12-byte fsx_pad member before copying it back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-09-10xfs: replace barriers with explicit flush / FUA usageChristoph Hellwig4-38/+3
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP detection for barriers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-03Merge branch '2.6.36-xfs-misc' of ↵Alex Elder3-11/+11
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/xfsdev
2010-09-03xfs: Make fiemap work with sparse filesTao Ma3-3/+17
In xfs_vn_fiemap, we set bvm_count to fi_extent_max + 1 and want to return fi_extent_max extents, but actually it won't work for a sparse file. The reason is that in xfs_getbmap we will calculate holes and set it in 'out', while out is malloced by bmv_count(fi_extent_max+1) which didn't consider holes. So in the worst case, if 'out' vector looks like [hole, extent, hole, extent, hole, ... hole, extent, hole], we will only return half of fi_extent_max extents. This patch add a new parameter BMV_IF_NO_HOLES for bvm_iflags. So with this flags, we don't use our 'out' in xfs_getbmap for a hole. The solution is a bit ugly by just don't increasing index of 'out' vector. I felt that it is not easy to skip it at the very beginning since we have the complicated check and some function like xfs_getbmapx_fix_eof_hole to adjust 'out'. Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-09-03xfs: prevent 32bit overflow in space reservationDave Chinner1-3/+10
If we attempt to preallocate more than 2^32 blocks of space in a single syscall, the transaction block reservation will overflow leading to a hangs in the superblock block accounting code. This is trivially reproduced with xfs_io. Fix the problem by capping the allocation reservation to the maximum number of blocks a single xfs_bmapi() call can allocate (2^21 blocks). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-09-02xfs: Disallow 32bit project quota idArkadiusz Mi?kiewicz1-0/+7
Currently on-disk structure is able to keep only 16bit project quota id, so disallow 32bit ones. This fixes a problem where parts of kernel structures holding project quota id are 32bit while parts (on-disk) are 16bit variables which causes project quota member files to be inaccessible for some operations (like mv/rm). Signed-off-by: Arkadiusz Mi?kiewicz <arekm@maven.pl> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>