summaryrefslogtreecommitdiff
path: root/fs/xfs/xfs_trans_ail.c
AgeCommit message (Collapse)Author
2021-08-19xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdownDave Chinner
Remove the shouty macro and instead use the inline function that matches other state/feature check wrapper naming. This conversion was done with sed. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-16xfs: AIL needs asynchronous CIL forcingDave Chinner
The AIL pushing is stalling on log forces when it comes across pinned items. This is happening on removal workloads where the AIL is dominated by stale items that are removed from AIL when the checkpoint that marks the items stale is committed to the journal. This results is relatively few items in the AIL, but those that are are often pinned as directories items are being removed from are still being logged. As a result, many push cycles through the CIL will first issue a blocking log force to unpin the items. This can take some time to complete, with tracing regularly showing push delays of half a second and sometimes up into the range of several seconds. Sequences like this aren't uncommon: .... 399.829437: xfsaild: last lsn 0x11002dd000 count 101 stuck 101 flushing 0 tout 20 <wanted 20ms, got 270ms delay> 400.099622: xfsaild: target 0x11002f3600, prev 0x11002f3600, last lsn 0x0 400.099623: xfsaild: first lsn 0x11002f3600 400.099679: xfsaild: last lsn 0x1100305000 count 16 stuck 11 flushing 0 tout 50 <wanted 50ms, got 500ms delay> 400.589348: xfsaild: target 0x110032e600, prev 0x11002f3600, last lsn 0x0 400.589349: xfsaild: first lsn 0x1100305000 400.589595: xfsaild: last lsn 0x110032e600 count 156 stuck 101 flushing 30 tout 50 <wanted 50ms, got 460ms delay> 400.950341: xfsaild: target 0x1100353000, prev 0x110032e600, last lsn 0x0 400.950343: xfsaild: first lsn 0x1100317c00 400.950436: xfsaild: last lsn 0x110033d200 count 105 stuck 101 flushing 0 tout 20 <wanted 20ms, got 200ms delay> 401.142333: xfsaild: target 0x1100361600, prev 0x1100353000, last lsn 0x0 401.142334: xfsaild: first lsn 0x110032e600 401.142535: xfsaild: last lsn 0x1100353000 count 122 stuck 101 flushing 8 tout 10 <wanted 10ms, got 10ms delay> 401.154323: xfsaild: target 0x1100361600, prev 0x1100361600, last lsn 0x1100353000 401.154328: xfsaild: first lsn 0x1100353000 401.154389: xfsaild: last lsn 0x1100353000 count 101 stuck 101 flushing 0 tout 20 <wanted 20ms, got 300ms delay> 401.451525: xfsaild: target 0x1100361600, prev 0x1100361600, last lsn 0x0 401.451526: xfsaild: first lsn 0x1100353000 401.451804: xfsaild: last lsn 0x1100377200 count 170 stuck 22 flushing 122 tout 50 <wanted 50ms, got 500ms delay> 401.933581: xfsaild: target 0x1100361600, prev 0x1100361600, last lsn 0x0 .... In each of these cases, every AIL pass saw 101 log items stuck on the AIL (pinned) with very few other items being found. Each pass, a log force was issued, and delay between last/first is the sleep time + the sync log force time. Some of these 101 items pinned the tail of the log. The tail of the log does slowly creep forward (first lsn), but the problem is that the log is actually out of reservation space because it's been running so many transactions that stale items that never reach the AIL but consume log space. Hence we have a largely empty AIL, with long term pins on items that pin the tail of the log that don't get pushed frequently enough to keep log space available. The problem is the hundreds of milliseconds that we block in the log force pushing the CIL out to disk. The AIL should not be stalled like this - it needs to run and flush items that are at the tail of the log with minimal latency. What we really need to do is trigger a log flush, but then not wait for it at all - we've already done our waiting for stuff to complete when we backed off prior to the log force being issued. Even if we remove the XFS_LOG_SYNC from the xfs_log_force() call, we still do a blocking flush of the CIL and that is what is causing the issue. Hence we need a new interface for the CIL to trigger an immediate background push of the CIL to get it moving faster but not to wait on that to occur. While the CIL is pushing, the AIL can also be pushing. We already have an internal interface to do this - xlog_cil_push_now() - but we need a wrapper for it to be used externally. xlog_cil_force_seq() can easily be extended to do what we need as it already implements the synchronous CIL push via xlog_cil_push_now(). Add the necessary flags and "push current sequence" semantics to xlog_cil_force_seq() and convert the AIL pushing to use it. One of the complexities here is that the CIL push does not guarantee that the commit record for the CIL checkpoint is written to disk. The current log force ensures this by submitting the current ACTIVE iclog that the commit record was written to. We need the CIL to actually write this commit record to disk for an async push to ensure that the checkpoint actually makes it to disk and unpins the pinned items in the checkpoint on completion. Hence we need to pass down to the CIL push that we are doing an async flush so that it can switch out the commit_iclog if necessary to get written to disk when the commit iclog is finally released. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2020-08-05xfs: delete duplicated words + other fixesRandy Dunlap
Delete repeated words in fs/xfs/. {we, that, the, a, to, fork} Change "it it" to "it is" in one location. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> To: linux-fsdevel@vger.kernel.org Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: linux-xfs@vger.kernel.org Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-28xfs: drain the buf delwri queue before xfsaild idlesBrian Foster
xfsaild is racy with respect to transaction abort and shutdown in that the task can idle or exit with an empty AIL but buffers still on the delwri queue. This was partly addressed by cancelling the delwri queue before the task exits to prevent memory leaks, but it's also possible for xfsaild to empty and idle with buffers on the delwri queue. For example, a transaction that pins a buffer that also happens to sit on the AIL delwri queue will explicitly remove the associated log item from the AIL if the transaction aborts. The side effect of this is an unmount hang in xfs_wait_buftarg() as the associated buffers remain held by the delwri queue indefinitely. This is reproduced on repeated runs of generic/531 with an fs format (-mrmapbt=1 -bsize=1k) that happens to also reproduce transaction aborts. Update xfsaild to not idle until both the AIL and associated delwri queue are empty and update the push code to continue delwri queue submission attempts even when the AIL is empty. This allows the AIL to eventually release aborted buffers stranded on the delwri queue when they are unlocked by the associated transaction. This should have no significant effect on normal runtime behavior because the xfsaild currently idles only when the AIL is empty and in practice the AIL is rarely empty with a populated delwri queue. The items must be AIL resident to land in the queue in the first place and generally aren't removed until writeback completes. Note that the pre-existing delwri queue cancel logic in the exit path is retained because task stop is external, could technically come at any point, and xfsaild is still responsible to release its buffer references before it exits. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-07xfs: pin inode backing buffer to the inode log itemDave Chinner
When we dirty an inode, we are going to have to write it disk at some point in the near future. This requires the inode cluster backing buffer to be present in memory. Unfortunately, under severe memory pressure we can reclaim the inode backing buffer while the inode is dirty in memory, resulting in stalling the AIL pushing because it has to do a read-modify-write cycle on the cluster buffer. When we have no memory available, the read of the cluster buffer blocks the AIL pushing process, and this causes all sorts of issues for memory reclaim as it requires inode writeback to make forwards progress. Allocating a cluster buffer causes more memory pressure, and results in more cluster buffers to be reclaimed, resulting in more RMW cycles to be done in the AIL context and everything then backs up on AIL progress. Only the synchronous inode cluster writeback in the the inode reclaim code provides some level of forwards progress guarantees that prevent OOM-killer rampages in this situation. Fix this by pinning the inode backing buffer to the inode log item when the inode is first dirtied (i.e. in xfs_trans_log_inode()). This may mean the first modification of an inode that has been held in cache for a long time may block on a cluster buffer read, but we can do that in transaction context and block safely until the buffer has been allocated and read. Once we have the cluster buffer, the inode log item takes a reference to it, pinning it in memory, and attaches it to the log item for future reference. This means we can always grab the cluster buffer from the inode log item when we need it. When the inode is finally cleaned and removed from the AIL, we can drop the reference the inode log item holds on the cluster buffer. Once all inodes on the cluster buffer are clean, the cluster buffer will be unpinned and it will be available for memory reclaim to reclaim again. This avoids the issues with needing to do RMW cycles in the AIL pushing context, and hence allows complete non-blocking inode flushing to be performed by the AIL pushing context. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-07xfs: move xfs_clear_li_failed out of xfs_ail_delete_one()Dave Chinner
xfs_ail_delete_one() is called directly from dquot and inode IO completion, as well as from the generic xfs_trans_ail_delete() function. Inodes are about to have their own failure handling, and dquots will in future, too. Pull the clearing of the LI_FAILED flag up into the callers so we can customise the code appropriately. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-08xfs: refactor adding recovered intent items to the logDarrick J. Wong
During recovery, every intent that we recover from the log has to be added to the AIL. Replace the open-coded addition with a helper. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
2020-05-07xfs: combine xfs_trans_ail_[remove|delete]()Brian Foster
Now that the functions and callers of xfs_trans_ail_[remove|delete]() have been fixed up appropriately, the only difference between the two is the shutdown behavior. There are only a few callers of the _remove() variant, so make the shutdown conditional on the parameter and combine the two functions. Suggested-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-07xfs: acquire ->ail_lock from xfs_trans_ail_delete()Brian Foster
Several callers acquire the lock just prior to the call. Callers that require ->ail_lock for other purposes already check IN_AIL state and thus don't require the additional shutdown check in the helper. Push the lock down into xfs_trans_ail_delete(), open code the instances that still acquire it, and remove the unnecessary ailp parameter. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-07xfs: refactor failed buffer resubmission into xfsaildBrian Foster
Flush locked log items whose underlying buffers fail metadata writeback are tagged with a special flag to indicate that the flush lock is already held. This is currently implemented in the type specific ->iop_push() callback, but the processing required for such items is not type specific because we're only doing basic state management on the underlying buffer. Factor the failed log item handling out of the inode and dquot ->iop_push() callbacks and open code the buffer resubmit helper into a single helper called from xfsaild_push_item(). This provides a generic mechanism for handling failed metadata buffer writeback with a bit less code. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-03-27xfs: tail updates only need to occur when LSN changesDave Chinner
We currently wake anything waiting on the log tail to move whenever the log item at the tail of the log is removed. Historically this was fine behaviour because there were very few items at any given LSN. But with delayed logging, there may be thousands of items at any given LSN, and we can't move the tail until they are all gone. Hence if we are removing them in near tail-first order, we might be waking up processes waiting on the tail LSN to change (e.g. log space waiters) repeatedly without them being able to make progress. This also occurs with the new sync push waiters, and can result in thousands of spurious wakeups every second when under heavy direct reclaim pressure. To fix this, check that the tail LSN has actually changed on the AIL before triggering wakeups. This will reduce the number of spurious wakeups when doing bulk AIL removal and make this code much more efficient. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-03-27xfs: factor common AIL item deletion codeDave Chinner
Factor the common AIL deletion code that does all the wakeups into a helper so we only have one copy of this somewhat tricky code to interface with all the wakeups necessary when the LSN of the log tail changes. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-03-11xfs: clear PF_MEMALLOC before exiting xfsaild threadEric Biggers
Leaving PF_MEMALLOC set when exiting a kthread causes it to remain set during do_exit(). That can confuse things. In particular, if BSD process accounting is enabled, then do_exit() writes data to an accounting file. If that file has FS_SYNC_FL set, then this write occurs synchronously and can misbehave if PF_MEMALLOC is set. For example, if the accounting file is located on an XFS filesystem, then a WARN_ON_ONCE() in iomap_do_writepage() is triggered and the data doesn't get written when it should. Or if the accounting file is located on an ext4 filesystem without a journal, then a WARN_ON_ONCE() in ext4_write_inode() is triggered and the inode doesn't get written. Fix this in xfsaild() by using the helper functions to save and restore PF_MEMALLOC. This can be reproduced as follows in the kvm-xfstests test appliance modified to add the 'acct' Debian package, and with kvm-xfstests's recommended kconfig modified to add CONFIG_BSD_PROCESS_ACCT=y: mkfs.xfs -f /dev/vdb mount /vdb touch /vdb/file chattr +S /vdb/file accton /vdb/file mkfs.xfs -f /dev/vdc mount /vdc umount /vdc It causes: WARNING: CPU: 1 PID: 336 at fs/iomap/buffered-io.c:1534 CPU: 1 PID: 336 Comm: xfsaild/vdc Not tainted 5.6.0-rc5 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014 RIP: 0010:iomap_do_writepage+0x16b/0x1f0 fs/iomap/buffered-io.c:1534 [...] Call Trace: write_cache_pages+0x189/0x4d0 mm/page-writeback.c:2238 iomap_writepages+0x1c/0x33 fs/iomap/buffered-io.c:1642 xfs_vm_writepages+0x65/0x90 fs/xfs/xfs_aops.c:578 do_writepages+0x41/0xe0 mm/page-writeback.c:2344 __filemap_fdatawrite_range+0xd2/0x120 mm/filemap.c:421 file_write_and_wait_range+0x71/0xc0 mm/filemap.c:760 xfs_file_fsync+0x7a/0x2b0 fs/xfs/xfs_file.c:114 generic_write_sync include/linux/fs.h:2867 [inline] xfs_file_buffered_aio_write+0x379/0x3b0 fs/xfs/xfs_file.c:691 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x130/0x1d0 fs/read_write.c:483 __kernel_write+0x54/0xe0 fs/read_write.c:515 do_acct_process+0x122/0x170 kernel/acct.c:522 slow_acct_process kernel/acct.c:581 [inline] acct_process+0x1d4/0x27c kernel/acct.c:607 do_exit+0x83d/0xbc0 kernel/exit.c:791 kthread+0xf1/0x140 kernel/kthread.c:257 ret_from_fork+0x27/0x50 arch/x86/entry/entry_64.S:352 This bug was originally reported by syzbot at https://lore.kernel.org/r/0000000000000e7156059f751d7b@google.com. Reported-by: syzbot+1f9dc49e8de2582d90c2@syzkaller.appspotmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-03-02xfs: Add missing annotation to xfs_ail_check()Jules Irenge
Sparse reports a warning at xfs_ail_check() warning: context imbalance in xfs_ail_check() - unexpected unlock The root cause is the missing annotation at xfs_ail_check() Add the missing __must_hold(&ailp->ail_lock) annotation Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-10xfs: Correct comment tyops -> typosJoe Perches
Just fix the typos checkpatch notices... Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-05xfs: use super s_id instead of struct xfs_mount m_fsnameIan Kent
Eliminate struct xfs_mount field m_fsname by using the super block s_id field directly. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-28xfs: remove the xfs_log_item_t typedefChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-28xfs: don't require log items to implement optional methodsChristoph Hellwig
Just check if they are present first. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-28xfs: move xfs_ino_geometry to xfs_shared.hDarrick J. Wong
The inode geometry structure isn't related to ondisk format; it's support for the mount structure. Move it to xfs_shared.h. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-10-18xfs: clear ail delwri queued bufs on unmount of shutdown fsBrian Foster
In the typical unmount case, the AIL is forced out by the unmount sequence before the xfsaild task is stopped. Since AIL items are removed on writeback completion, this means that the AIL ->ail_buf_list delwri queue has been drained. This is not always true in the shutdown case, however. It's possible for buffers to sit on a delwri queue for a period of time across submission attempts if said items are locked or have been relogged and pinned since first added to the queue. If the attempt to log such an item results in a log I/O error, the error processing can shutdown the fs, remove the item from the AIL, stale the buffer (dropping the LRU reference) and clear its delwri queue state. The latter bit means the buffer will be released from a delwri queue on the next submission attempt, but this might never occur if the filesystem has shutdown and the AIL is empty. This means that such buffers are held indefinitely by the AIL delwri queue across destruction of the AIL. Aside from being a memory leak, these buffers can also hold references to in-core perag structures. The latter problem manifests as a generic/475 failure, reproducing the following asserts at unmount time: XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 151 XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 132 To prevent this problem, clear the AIL delwri queue as a final step before xfsaild() exit. The !empty state should never occur in the normal case, so add an assert to catch unexpected problems going forward. [dgc: add comment explaining need for xfs_buf_delwri_cancel() after calling xfs_buf_delwri_submit_nowait().] Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-06-06xfs: convert to SPDX license tagsDave Chinner
Remove the verbose license text from XFS files and replace them with SPDX tags. This does not change the license of any of the code, merely refers to the common, up-to-date license files in LICENSES/ This change was mostly scripted. fs/xfs/Makefile and fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected and modified by the following command: for f in `git grep -l "GNU General" fs/xfs/` ; do echo $f cat $f | awk -f hdr.awk > $f.new mv -f $f.new $f done And the hdr.awk script that did the modification (including detecting the difference between GPL-2.0 and GPL-2.0+ licenses) is as follows: $ cat hdr.awk BEGIN { hdr = 1.0 tag = "GPL-2.0" str = "" } /^ \* This program is free software/ { hdr = 2.0; next } /any later version./ { tag = "GPL-2.0+" next } /^ \*\// { if (hdr > 0.0) { print "// SPDX-License-Identifier: " tag print str print $0 str="" hdr = 0.0 next } print $0 next } /^ \* / { if (hdr > 1.0) next if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 next } /^ \*/ { if (hdr > 0.0) next print $0 next } // { if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 } END { } $ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-10xfs: don't assert fail with AIL lock heldDave Chinner
Been hitting AIL ordering assert failures recently, but been unable to trace them down because the system immediately hangs up onteh spinlock that was held when this assert fires: XFS: Assertion failed: XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0, file: fs/xfs/xfs_trans_ail.c, line: 52 Move the assertions outside of the spinlock so the corpse can be dissected. Thanks to Brian Foster for supplying a clean way of doing this. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-10xfs: log item flags are racyDave Chinner
The log item flags contain a field that is protected by the AIL lock - the XFS_LI_IN_AIL flag. We use non-atomic RMW operations to set and clear these flags, but most of the updates and checks are not done with the AIL lock held and so are susceptible to update races. Fix this by changing the log item flags to use atomic bitops rather than be reliant on the AIL lock for update serialisation. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-03-11xfs: Rename xa_ elements to ail_Matthew Wilcox
This is a simple rename, except that xa_ail becomes ail_head. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-01xfs: move error injection tags into their own fileDarrick J. Wong
Move the error injection tag names into a libxfs header so that we can share it between kernel and userspace. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26xfs: check kthread_should_stop() after the setting of task stateHou Tao
A umount hang is possible when a race occurs between the umount process and the xfsaild kthread. The following sequences outline the race: xfsaild: kthread_should_stop() => return false, so xfsaild continue umount: set_bit(KTHREAD_SHOULD_STOP, &kthread->flags) => by kthread_stop() umount: wake_up_process() => because xfsaild is still running, so 0 is returned xfsaild: __set_current_state(TASK_INTERRUPTIBLE) xfsaild: schedule() => now, xfsaild will wait indefinitely umount: wait_for_completion() => and umount will hang To fix that, we need to check kthread_should_stop() after we set the task state, so the xfsaild will either see the stop bit and exit or the task state is reset to runnable by wake_up_process() such that it isn't scheduled out indefinitely and detects the stop bit at the next iteration. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-22xfs: add log item pinning error injection tagBrian Foster
Add an error injection tag to force log items in the AIL to the pinned state. This option can be used by test infrastructure to induce head behind tail conditions. Specifically, this is intended to be used by xfstests to reproduce log recovery problems after failed/corrupted log writes overwrite the last good tail LSN in the log. When enabled, AIL push attempts see log items in the AIL in the pinned state. This stalls metadata writeback and thus prevents the current tail of the log from moving forward. When disabled, subsequent AIL pushes observe the log items in their appropriate state and filesystem operation continues as normal. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-22xfs: Properly retry failed inode items in case of error during buffer writebackCarlos Maiolino
When a buffer has been failed during writeback, the inode items into it are kept flush locked, and are never resubmitted due the flush lock, so, if any buffer fails to be written, the items in AIL are never written to disk and never unlocked. This causes unmount operation to hang due these items flush locked in AIL, but this also causes the items in AIL to never be written back, even when the IO device comes back to normal. I've been testing this patch with a DM-thin device, creating a filesystem larger than the real device. When writing enough data to fill the DM-thin device, XFS receives ENOSPC errors from the device, and keep spinning on xfsaild (when 'retry forever' configuration is set). At this point, the filesystem can not be unmounted because of the flush locked items in AIL, but worse, the items in AIL are never retried at all (once xfs_inode_item_push() will skip the items that are flush locked), even if the underlying DM-thin device is expanded to the proper size. This patch fixes both cases, retrying any item that has been failed previously, using the infra-structure provided by the previous patch. Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-04-25xfs: remove xfs_trans_ail_delete_bulkChristoph Hellwig
xfs_iflush_done uses an on-stack variable length array to pass the log items to be deleted to xfs_trans_ail_delete_bulk. On-stack VLAs are a nasty gcc extension that can lead to unbounded stack allocations, but fortunately we can easily avoid them by simply open coding xfs_trans_ail_delete_bulk in xfs_iflush_done, which is the only caller of it except for the single-item xfs_trans_ail_delete. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-02-08xfs: Make xfsaild freezeable againMichal Hocko
Hendik has reported suspend failures due to xfsaild blocking the freezer to settle down. Jan 17 19:59:56 linux-6380 kernel: PM: Syncing filesystems ... done. Jan 17 19:59:56 linux-6380 kernel: PM: Preparing system for sleep (mem) Jan 17 19:59:56 linux-6380 kernel: Freezing user space processes ... (elapsed 0.001 seconds) done. Jan 17 19:59:56 linux-6380 kernel: Freezing remaining freezable tasks ... Jan 17 19:59:56 linux-6380 kernel: Freezing of tasks failed after 20.002 seconds (1 tasks refusing to freeze, wq_busy=0): Jan 17 19:59:56 linux-6380 kernel: xfsaild/dm-5 S 00000000 0 1293 2 0x00000080 Jan 17 19:59:56 linux-6380 kernel: f0ef5f00 00000046 00000200 00000000 ffff9022 c02d3800 00000000 00000032 Jan 17 19:59:56 linux-6380 kernel: ee0b2400 00000032 f71e0d00 f36fabc0 f0ef2d00 f0ef6000 f0ef2d00 f12f90c0 Jan 17 19:59:56 linux-6380 kernel: f0ef5f0c c0844e44 00000000 f0ef5f6c f811e0be 00000000 00000000 f0ef2d00 Jan 17 19:59:56 linux-6380 kernel: Call Trace: Jan 17 19:59:56 linux-6380 kernel: [<c0844e44>] schedule+0x34/0x90 Jan 17 19:59:56 linux-6380 kernel: [<f811e0be>] xfsaild+0x5de/0x600 [xfs] Jan 17 19:59:56 linux-6380 kernel: [<c0286cbb>] kthread+0x9b/0xb0 Jan 17 19:59:56 linux-6380 kernel: [<c0848a79>] ret_from_kernel_thread+0x21/0x38 The issue has been there for quite some time but it has been made visible by only by 24ba16bb3d49 ("xfs: clear PF_NOFREEZE for xfsaild kthread") because the suspend started seeing xfsaild. The above commit has missed that the !xfs_ail_min branch might call schedule with TASK_INTERRUPTIBLE without calling try_to_freeze so the pm suspend would wake up the kernel thread over and over again without any progress. What we want here is to use freezable_schedule instead to hide the thread from the suspend. While we are here also change schedule_timeout to freezable variant to prevent from spurious wakeups by suspend. [dchinner: re-add set_freezeable call so the freezer will account properly for this kthread. ] Reported-by: Hendrik Woltersdorf <hendrikw@arcor.de> Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-19Revert "xfs: clear PF_NOFREEZE for xfsaild kthread"Dave Chinner
This reverts commit 24ba16bb3d499c49974669cd8429c3e4138ab102 as it prevents machines from suspending. This regression occurs when the xfsaild is idle on entry to suspend, and so there s no activity to wake it from it's idle sleep and hence see that it is supposed to freeze. Hence the freezer times out waiting for it and suspend is cancelled. There is no obvious fix for this short of freezing the filesystem properly, so revert this change for now. cc: <stable@vger.kernel.org> # 4.4 Signed-off-by: Dave Chinner <david@fromorbit.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03Merge branch 'xfs-misc-fixes-for-4.4-2' into for-nextDave Chinner
2015-11-02xfs: clear PF_NOFREEZE for xfsaild kthreadJiri Kosina
Since xfsaild has been converted to kthread in 0030807c, it calls try_to_freeze() during every AIL push iteration. It however doesn't set itself as freezable, and therefore this try_to_freeze() will never do anything. Before (hopefully eventually) kthread freezing gets converted to fileystem freezing, we'd rather mark xfsaild freezable (as it can generate I/O during suspend). Signed-off-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12xfs: per-filesystem stats counter implementationBill O'Donnell
This patch modifies the stats counting macros and the callers to those macros to properly increment, decrement, and add-to the xfs stats counts. The counts for global and per-fs stats are correctly advanced, and cleared by writing a "1" to the corresponding clear file. global counts: /sys/fs/xfs/stats/stats per-fs counts: /sys/fs/xfs/sda*/stats/stats global clear: /sys/fs/xfs/stats/stats_clear per-fs clear: /sys/fs/xfs/sda*/stats/stats_clear [dchinner: cleaned up macro variables, removed CONFIG_FS_PROC around stats structures and macros. ] Signed-off-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-22xfs: remove __psint_t and __psunsigned_tChristoph Hellwig
Replace uses of __psint_t with the proper uintptr_t and ptrdiff_t types, and remove the defintions of __psint_t and __psunsigned_t. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28xfs: move most of xfs_sb.h to xfs_format.hChristoph Hellwig
More on-disk format consolidation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28xfs: merge xfs_ag.h into xfs_format.hChristoph Hellwig
More on-disk format consolidation. A few declarations that weren't on-disk format related move into better suitable spots. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-25xfs: global error sign conversionDave Chinner
Convert all the errors the core XFs code to negative error signs like the rest of the kernel and remove all the sign conversion we do in the interface layers. Errors for conversion (and comparison) found via searches like: $ git grep " E" fs/xfs $ git grep "return E" fs/xfs $ git grep " E[A-Z].*;$" fs/xfs Negation points found via searches like: $ git grep "= -[a-z,A-Z]" fs/xfs $ git grep "return -[a-z,A-D,F-Z]" fs/xfs $ git grep " -[a-z].*;" fs/xfs [ with some bits I missed from Brian Foster ] Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-04-14xfs: remove unused ail pointer arg from xfs_trans_ail_cursor_done()Eric Sandeen
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2013-11-06xfs: trace AIL manipulationsDave Chinner
I debugging a log tail issue on a RHEL6 kernel, I added these trace points to trace log items being added, moved and removed in the AIL and how that affected the log tail LSN that was written to the log. They were very helpful in that they immediately identified the cause of the problem being seen. Hence I'd like to always have them available for use. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-23xfs: decouple log and transaction headersDave Chinner
xfs_trans.h has a dependency on xfs_log.h for a couple of structures. Most code that does transactions doesn't need to know anything about the log, but this dependency means that they have to include xfs_log.h. Decouple the xfs_trans.h and xfs_log.h header files and clean up the includes to be in dependency order. In doing this, remove the direct include of xfs_trans_reserve.h from xfs_trans.h so that we remove the dependency between xfs_trans.h and xfs_mount.h. Hence the xfs_trans.h include can be moved to the indicate the actual dependencies other header files have on it. Note that these are kernel only header files, so this does not translate to any userspace changes at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-30xfs: finish removing IOP_* macros.Dave Chinner
In optimising the CIL operations, some of the IOP_* macros for calling log item operations were removed. Remove the rest of them as Christoph requested. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Geoffrey Wehrman <gwehrman@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-23xfs: Simplify xfs_ail_min() with list_first_entry_or_null()Jie Liu
At xfs_ail_min(), we do check if the AIL list is empty or not before returning the first item in it with list_empty() and list_first_entry(). This can be simplified a bit with a new list operation routine that is the list_first_entry_or_null() which has been introduced by: commit 6d7581e62f8be462440d7b22c6361f7c9fa4902b list: introduce list_first_entry_or_null v2: make xfs_ail_min() as a static inline function and move it to xfs_trans_priv.h as per Dave Chinner's comments. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-12-17xfs remove the XFS_TRANS_DEBUG routinesMark Tinguely
Remove the XFS_TRANS_DEBUG routines. They are no longer appropriate and have not been used in years Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-29xfs: re-enable xfsaild idle mode and fix associated racesBrian Foster
xfsaild idle mode logic currently leads to a couple hangs: 1.) If xfsaild is rescheduled in during an incremental scan (i.e., tout != 0) and the target has been updated since the previous run, we can hit the new target and go into idle mode with a still populated ail. 2.) A wake up is only issued when the target is pushed forward. The wake up can race with xfsaild if it is currently in the process of entering idle mode, causing future wake up events to be lost. These hangs have been reproduced and verified as fixed by running xfstests 273 in a loop on a slightly modified upstream kernel. The kernel is modified to re-enable idle mode as previously implemented (when count == 0) and with a revert of commit 670ce93f, which includes performance improvements that make this harder to reproduce. The solution, the algorithm for which has been outlined by Dave Chinner, is to modify xfsaild to enter idle mode only when the ail is empty and the push target has not been moved forward since the last push. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: move xfsagino_t to xfs_types.hDave Chinner
Untangle the header file includes a bit by moving the definition of xfs_agino_t to xfs_types.h. This removes the dependency that xfs_ag.h has on xfs_inum.h, meaning we don't need to include xfs_inum.h everywhere we include xfs_ag.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: remove some obsolete comments in xfs_trans_ail.cChristoph Hellwig
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: 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: 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>