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2012-10-17xfs: rename xfs_sync.[ch] to xfs_icache.[ch]Dave Chinner
xfs_sync.c now only contains inode reclaim functions and inode cache iteration functions. It is not related to sync operations anymore. Rename to xfs_icache.c to reflect it's contents and prepare for consolidation with the other inode cache file that exists (xfs_iget.c). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: move xfs_quiesce_attr() into xfs_super.cDave Chinner
Both callers of xfs_quiesce_attr() are in xfs_super.c, and there's nothing really sync-specific about this functionality so it doesn't really matter where it lives. Move it to benext to it's callers, so all the remount/sync_fs code is in the one place. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: xfs_sync_fsdata is redundantDave Chinner
Why do we need to write the superblock to disk once we've written all the data? We don't actually - the reasons for doing this are lost in the mists of time, and go back to the way Irix used to drive VFS flushing. On linux, this code is only called from two contexts: remount and .sync_fs. In the remount case, the call is followed by a metadata sync, which unpins and writes the superblock. In the sync_fs case, we only need to force the log to disk to ensure that the superblock is correctly on disk, so we don't actually need to write it. Hence the functionality is either redundant or superfluous and thus can be removed. Seeing as xfs_quiesce_data is essentially now just a log force, remove it as well and fold the code back into the two callers. Neither of them need the log covering check, either, as that is redundant for the remount case, and unnecessary for the .sync_fs case. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: syncd workqueue is no moreDave Chinner
With the syncd functions moved to the log and/or removed, the syncd workqueue is the only remaining bit left. It is used by the log covering/ail pushing work, as well as by the inode reclaim work. Given how cheap workqueues are these days, give the log and inode reclaim work their own work queues and kill the syncd work queue. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: xfs_sync_data is redundant.Dave Chinner
We don't do any data writeback from XFS any more - the VFS is completely responsible for that, including for freeze. We can replace the remaining caller with a VFS level function that achieves the same thing, but without conflicting with current writeback work. This means we can remove the flush_work and xfs_flush_inodes() - the VFS functionality completely replaces the internal flush queue for doing this writeback work in a separate context to avoid stack overruns. This does have one complication - it cannot be called with page locks held. Hence move the flushing of delalloc space when ENOSPC occurs back up into xfs_file_aio_buffered_write when we don't hold any locks that will stall writeback. Unfortunately, writeback_inodes_sb_if_idle() is not sufficient to trigger delalloc conversion fast enough to prevent spurious ENOSPC whent here are hundreds of writers, thousands of small files and GBs of free RAM. Hence we need to use sync_sb_inodes() to block callers while we wait for writeback like the previous xfs_flush_inodes implementation did. That means we have to hold the s_umount lock here, but because this call can nest inside i_mutex (the parent directory in the create case, held by the VFS), we have to use down_read_trylock() to avoid potential deadlocks. In practice, this trylock will succeed on almost every attempt as unmount/remount type operations are exceedingly rare. Note: we always need to pass a count of zero to generic_file_buffered_write() as the previously written byte count. We only do this by accident before this patch by the virtue of ret always being zero when there are no errors. Make this explicit rather than needing to specifically zero ret in the ENOSPC retry case. Signed-off-by: Dave Chinner <dchinner@redhat.com> Tested-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: sync work is now only periodic log workDave Chinner
The only thing the periodic sync work does now is flush the AIL and idle the log. These are really functions of the log code, so move the work to xfs_log.c and rename it appropriately. The only wart that this leaves behind is the xfssyncd_centisecs sysctl, otherwise the xfssyncd is dead. Clean up any comments that related to xfssyncd to reflect it's passing. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: don't run the sync work if the filesystem is read-onlyDave Chinner
If the filesystem is mounted or remounted read-only, stop the sync worker that tries to flush or cover the log if the filesystem is dirty. It's read-only, so it isn't dirty. Restart it on a remount,rw as necessary. This avoids the need for RO checks in the work. Similarly, stop the sync work when the filesystem is frozen, and start it again when the filesysetm is thawed. This avoids the need for special freeze checks in the work. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: rationalise xfs_mount_wq usersDave Chinner
Instead of starting and stopping background work on the xfs_mount_wq all at the same time, separate them to where they really are needed to start and stop. The xfs_sync_worker, only needs to be started after all the mount processing has completed successfully, while it needs to be stopped before the log is unmounted. The xfs_reclaim_worker is started on demand, and can be stopped before the unmount process does it's own inode reclaim pass. The xfs_flush_inodes work is run on demand, and so we really only need to ensure that it has stopped running before we start processing an unmount, freeze or remount,ro. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: xfs_syncd_stop must dieDave Chinner
xfs_syncd_start and xfs_syncd_stop tie a bunch of unrelated functionailty together that actually have different start and stop requirements. Kill these functions and open code the start/stop methods for each of the background functions. Subsequent patches will move the start/stop functions around to the correct places to avoid races and shutdown issues. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-08-20workqueue: deprecate flush[_delayed]_work_sync()Tejun Heo
flush[_delayed]_work_sync() are now spurious. Mark them deprecated and convert all users to flush[_delayed]_work(). If you're cc'd and wondering what's going on: Now all workqueues are non-reentrant and the regular flushes guarantee that the work item is not pending or running on any CPU on return, so there's no reason to use the sync flushes at all and they're going away. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Mattia Dongili <malattia@linux.it> Cc: Kent Yoder <key@linux.vnet.ibm.com> Cc: David Airlie <airlied@linux.ie> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Bryan Wu <bryan.wu@canonical.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-wireless@vger.kernel.org Cc: Anton Vorontsov <cbou@mail.ru> Cc: Sangbeom Kim <sbkim73@samsung.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Petr Vandrovec <petr@vandrovec.name> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Avi Kivity <avi@redhat.com>
2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
2012-07-31xfs: Convert to new freezing codeJan Kara
Generic code now blocks all writers from standard write paths. So we add blocking of all writers coming from ioctl (we get a protection of ioctl against racing remount read-only as a bonus) and convert xfs_file_aio_write() to a non-racy freeze protection. We also keep freeze protection on transaction start to block internal filesystem writes such as removal of preallocated blocks. CC: Ben Myers <bpm@sgi.com> CC: Alex Elder <elder@kernel.org> CC: xfs@oss.sgi.com Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29xfs: wait for the write the superblock on unmountMark Tinguely
v2: Add the xfs_buf_lock to xfs_quiesce_attr(). Add explaination why xfs_buf_lock() is used to wait for write. xfs_wait_buftarg() does not wait for the completion of the write of the uncached superblock. This write can race with the shutdown of the log and causes a panic if the write does not win the race. During the log write, xfsaild_push() will lock the buffer and set the XBF_ASYNC flag. Because the XBF_FLAG is set, complete() is not performed on the buffer's iowait entry, we cannot call xfs_buf_iowait() to wait for the write to complete. The buffer's lock is held until the write is complete, so we can block on a xfs_buf_lock() request to be notified that the write is complete. Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-22xfs: merge xfs_itobp into xfs_imap_to_bpChristoph Hellwig
All callers of xfs_imap_to_bp want the dinode pointer, so let's calculate it inside xfs_imap_to_bp. Once that is done xfs_itobp becomes a fairly pointless wrapper which can be replaced with direct calls to xfs_imap_to_bp. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-21xfs: shutdown xfs_sync_worker before the logBen Myers
Revert commit 1307bbd, which uses the s_umount semaphore to provide exclusion between xfs_sync_worker and unmount, in favor of shutting down the sync worker before freeing the log in xfs_log_unmount. This is a cleaner way of resolving the race between xfs_sync_worker and unmount than using s_umount. Signed-off-by: Ben Myers <bpm@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2012-06-21xfs: shutdown xfs_sync_worker before the logBen Myers
Revert commit 1307bbd, which uses the s_umount semaphore to provide exclusion between xfs_sync_worker and unmount, in favor of shutting down the sync worker before freeing the log in xfs_log_unmount. This is a cleaner way of resolving the race between xfs_sync_worker and unmount than using s_umount. Signed-off-by: Ben Myers <bpm@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2012-05-15xfs: protect xfs_sync_worker with s_umount semaphoreBen Myers
xfs_sync_worker checks the MS_ACTIVE flag in s_flags to avoid doing work during mount and unmount. This flag can be cleared by unmount after the xfs_sync_worker checks it but before the work is completed. The has caused crashes in the completion handler for the dummy transaction commited by xfs_sync_worker: PID: 27544 TASK: ffff88013544e040 CPU: 3 COMMAND: "kworker/3:0" #0 [ffff88016fdff930] machine_kexec at ffffffff810244e9 #1 [ffff88016fdff9a0] crash_kexec at ffffffff8108d053 #2 [ffff88016fdffa70] oops_end at ffffffff813ad1b8 #3 [ffff88016fdffaa0] no_context at ffffffff8102bd48 #4 [ffff88016fdffaf0] __bad_area_nosemaphore at ffffffff8102c04d #5 [ffff88016fdffb40] bad_area_nosemaphore at ffffffff8102c12e #6 [ffff88016fdffb50] do_page_fault at ffffffff813afaee #7 [ffff88016fdffc60] page_fault at ffffffff813ac635 [exception RIP: xlog_get_lowest_lsn+0x30] RIP: ffffffffa04a9910 RSP: ffff88016fdffd10 RFLAGS: 00010246 RAX: ffffc90014e48000 RBX: ffff88014d879980 RCX: ffff88014d879980 RDX: ffff8802214ee4c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88016fdffd10 R8: ffff88014d879a80 R9: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8802214ee400 R13: ffff88014d879980 R14: 0000000000000000 R15: ffff88022fd96605 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #8 [ffff88016fdffd18] xlog_state_do_callback at ffffffffa04aa186 [xfs] #9 [ffff88016fdffd98] xlog_state_done_syncing at ffffffffa04aa568 [xfs] Protect xfs_sync_worker by using the s_umount semaphore at the read level to provide exclusion with unmount while work is progressing. Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: clean up xfs_bit.h includesDave Chinner
With the removal of xfs_rw.h and other changes over time, xfs_bit.h is being included in many files that don't actually need it. Clean up the includes as necessary. Also move the only-used-once xfs_ialloc_find_free() static inline function out of a header file that is widely included to reduce the number of needless dependencies on xfs_bit.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: pass shutdown method into xfs_trans_ail_delete_bulkDave Chinner
xfs_trans_ail_delete_bulk() can be called from different contexts so if the item is not in the AIL we need different shutdown for each context. Pass in the shutdown method needed so the correct action can be taken. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: on-stack delayed write buffer listsChristoph Hellwig
Queue delwri buffers on a local on-stack list instead of a per-buftarg one, and write back the buffers per-process instead of by waking up xfsbufd. This is now easily doable given that we have very few places left that write delwri buffers: - log recovery: Only done at mount time, and already forcing out the buffers synchronously using xfs_flush_buftarg - quotacheck: Same story. - dquot reclaim: Writes out dirty dquots on the LRU under memory pressure. We might want to look into doing more of this via xfsaild, but it's already more optimal than the synchronous inode reclaim that writes each buffer synchronously. - xfsaild: This is the main beneficiary of the change. By keeping a local list of buffers to write we reduce latency of writing out buffers, and more importably we can remove all the delwri list promotions which were hitting the buffer cache hard under sustained metadata loads. The implementation is very straight forward - xfs_buf_delwri_queue now gets a new list_head pointer that it adds the delwri buffers to, and all callers need to eventually submit the list using xfs_buf_delwi_submit or xfs_buf_delwi_submit_nowait. Buffers that already are on a delwri list are skipped in xfs_buf_delwri_queue, assuming they already are on another delwri list. The biggest change to pass down the buffer list was done to the AIL pushing. Now that we operate on buffers the trylock, push and pushbuf log item methods are merged into a single push routine, which tries to lock the item, and if possible add the buffer that needs writeback to the buffer list. This leads to much simpler code than the previous split but requires the individual IOP_PUSH instances to unlock and reacquire the AIL around calls to blocking routines. Given that xfsailds now also handle writing out buffers, the conditions for log forcing and the sleep times needed some small changes. The most important one is that we consider an AIL busy as long we still have buffers to push, and the other one is that we do increment the pushed LSN for buffers that are under flushing at this moment, but still count them towards the stuck items for restart purposes. Without this we could hammer on stuck items without ever forcing the log and not make progress under heavy random delete workloads on fast flash storage devices. [ Dave Chinner: - rebase on previous patches. - improved comments for XBF_DELWRI_Q handling - fix XBF_ASYNC handling in queue submission (test 106 failure) - rename delwri submit function buffer list parameters for clarity - xfs_efd_item_push() should return XFS_ITEM_PINNED ] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: do not write the buffer from xfs_iflushChristoph Hellwig
Instead of writing the buffer directly from inside xfs_iflush return it to the caller and let the caller decide what to do with the buffer. Also remove the pincount check in xfs_iflush that all non-blocking callers already implement and the now unused flags parameter. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: don't flush inodes from background inode reclaimChristoph Hellwig
We already flush dirty inodes throug the AIL regularly, there is no reason to have second thread compete with it and disturb the I/O pattern. We still do write inodes when doing a synchronous reclaim from the shrinker or during unmount for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: implement freezing by emptying the AILChristoph Hellwig
Now that we write back all metadata either synchronously or through the AIL we can simply implement metadata freezing in terms of emptying the AIL. The implementation for this is fairly simply and straight-forward: A new routine is added that asks the xfsaild to push the AIL to the end and waits for it to complete and send a wakeup. The routine will then loop if the AIL is not actually empty, and continue to do so until the AIL is compeltely empty. We keep an inode reclaim pass in the freeze process to avoid having memory pressure have to reclaim inodes that require dirtying the filesystem to be reclaimed after the freeze has completed. This means we can also treat unmount in the exact same way as freeze. As an upside we can now remove the radix tree based inode writeback and xfs_unmountfs_writesb. [ Dave Chinner: - Cleaned up commit message. - Added inode reclaim passes back into freeze. - Cleaned up wakeup mechanism to avoid the use of a new sleep counter variable. ] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: remove log item from AIL in xfs_iflush after a shutdownChristoph Hellwig
If a filesystem has been forced shutdown we are never going to write inodes to disk, which means the inode items will stay in the AIL until we free the inode. Currently that is not a problem, but a pending change requires us to empty the AIL before shutting down the filesystem. In that case leaving the inode in the AIL is lethal. Make sure to remove the log item from the AIL to allow emptying the AIL on shutdown filesystems. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-04-17xfs: Ensure inode reclaim can run during quotacheckDave Chinner
Because the mount process can run a quotacheck and consume lots of inodes, we need to be able to run periodic inode reclaim during the mount process. This will prevent running the system out of memory during quota checks. This essentially reverts 2bcf6e97, but that is safe to do now that the quota sync code that was causing problems during long quotacheck executions is now gone. The reclaim work is currently protected from running during the unmount process by a check against MS_ACTIVE. Unfortunately, this also means that the reclaim work cannot run during mount. The unmount process should stop the reclaim cleanly before freeing anything that the reclaim work depends on, so there is no need to have this guard in place. Also, the inode reclaim work is demand driven, so there is no need to start it immediately during mount. It will be started the moment an inode is queued for reclaim, so qutoacheck will trigger it just fine. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-13xfs: log timestamp updatesChristoph Hellwig
Timestamps on regular files are the last metadata that XFS does not update transactionally. Now that we use the delaylog mode exclusively and made the log scode scale extremly well there is no need to bypass that code for timestamp updates. Logging all updates allows to drop a lot of code, and will allow for further performance improvements later on. Note that this patch drops optimized handling of fdatasync - it will be added back in a separate commit. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-02-25xfs: only take the ILOCK in xfs_reclaim_inode()Alex Elder
At the end of xfs_reclaim_inode(), the inode is locked in order to we wait for a possible concurrent lookup to complete before the inode is freed. This synchronization step was taking both the ILOCK and the IOLOCK, but the latter was causing lockdep to produce reports of the possibility of deadlock. It turns out that there's no need to acquire the IOLOCK at this point anyway. It may have been required in some earlier version of the code, but there should be no need to take the IOLOCK in xfs_iget(), so there's no (longer) any need to get it here for synchronization. Add an assertion in xfs_iget() as a reminder of this assumption. Dave Chinner diagnosed this on IRC, and Christoph Hellwig suggested no longer including the IOLOCK. I just put together the patch. Signed-off-by: Alex Elder <elder@dreamhost.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: replace i_flock with a sleeping bitlockChristoph Hellwig
We almost never block on i_flock, the exception is synchronous inode flushing. Instead of bloating the inode with a 16/24-byte completion that we abuse as a semaphore just implement it as a bitlock that uses a bit waitqueue for the rare sleeping path. This primarily is a tradeoff between a much smaller inode and a faster non-blocking path vs faster wakeups, and we are much better off with the former. A small downside is that we will lose lockdep checking for i_flock, but given that it's always taken inside the ilock that should be acceptable. Note that for example the inode writeback locking is implemented in a very similar way. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-08Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (22 commits) xfs: mark the xfssyncd workqueue as non-reentrant xfs: simplify xfs_qm_detach_gdquots xfs: fix acl count validation in xfs_acl_from_disk() xfs: remove unused XBT_FORCE_SLEEP bit xfs: remove XFS_QMOPT_DQSUSER xfs: kill xfs_qm_idtodq xfs: merge xfs_qm_dqinit_core into the only caller xfs: add a xfs_dqhold helper xfs: simplify xfs_qm_dqattach_grouphint xfs: nest qm_dqfrlist_lock inside the dquot qlock xfs: flatten the dquot lock ordering xfs: implement lazy removal for the dquot freelist xfs: remove XFS_DQ_INACTIVE xfs: cleanup xfs_qm_dqlookup xfs: cleanup dquot locking helpers xfs: remove the sync_mode argument to xfs_qm_dqflush_all xfs: remove xfs_qm_sync xfs: make sure to really flush all dquots in xfs_qm_quotacheck xfs: untangle SYNC_WAIT and SYNC_TRYLOCK meanings for xfs_qm_dqflush xfs: remove the lid_size field in struct log_item_desc ... Fix up trivial conflict in fs/xfs/xfs_sync.c
2011-12-23xfs: log all dirty inodes in xfs_fs_sync_fsChristoph Hellwig
Since Linux 2.6.36 the writeback code has introduces various measures for live lock prevention during sync(). Unfortunately some of these are actively harmful for the XFS model, where the inode gets marked dirty for metadata from the data I/O handler. The older_than_this checks that are now more strictly enforced since writeback: avoid livelocking WB_SYNC_ALL writeback by only calling into __writeback_inodes_sb and thus only sampling the current cut off time once. But on a slow enough devices the previous asynchronous sync pass might not have fully completed yet, and thus XFS might mark metadata dirty only after that sampling of the cut off time for the blocking pass already happened. I have not myself reproduced this myself on a real system, but by introducing artificial delay into the XFS I/O completion workqueues it can be reproduced easily. Fix this by iterating over all XFS inodes in ->sync_fs and log all that are dirty. This might log inode that only got redirtied after the previous pass, but given how cheap delayed logging of inodes is it isn't a major concern for performance. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Tested-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2011-12-12xfs: remove xfs_qm_syncChristoph Hellwig
Now that we can't have any dirty dquots around that aren't in the AIL we can get rid of the explicit dquot syncing from xfssyncd and xfs_fs_sync_fs and instead rely on AIL pushing to write out any quota updates. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2011-11-29xfs: force buffer writeback before blocking on the ilock in inode reclaimChristoph Hellwig
If we are doing synchronous inode reclaim we block the VM from making progress in memory reclaim. So if we encouter a flush locked inode promote it in the delwri list and wake up xfsbufd to write it out now. Without this we can get hangs of up to 30 seconds during workloads hitting synchronous inode reclaim. The scheme is copied from what we do for dquot reclaims. Reported-by: Simon Kirby <sim@hostway.ca> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Simon Kirby <sim@hostway.ca> Signed-off-by: Ben Myers <bpm@sgi.com>
2011-10-11xfs: remove XFS_bflushChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: remove i_iocountChristoph Hellwig
We now have an i_dio_count filed and surrounding infrastructure to wait for direct I/O completion instead of i_icount, and we have never needed to iocount waits for buffered I/O given that we only set the page uptodate after finishing all required work. Thus remove i_iocount, and replace the actually needed waits with calls to inode_dio_wait. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: let xfs_bwrite callers handle the xfs_buf_relseChristoph Hellwig
Remove the xfs_buf_relse from xfs_bwrite and let the caller handle it to mirror the delwri and read paths. Also remove the mount pointer passed to xfs_bwrite, which is superflous now that we have a mount pointer in the buftarg. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-08-12xfs: remove subdirectoriesChristoph Hellwig
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>