linux/fs/xfs
Brian Foster 6191cf3ad5 xfs: flush inodegc workqueue tasks before cancel
The xfs_inodegc_stop() helper performs a high level flush of pending
work on the percpu queues and then runs a cancel_work_sync() on each
of the percpu work tasks to ensure all work has completed before
returning.  While cancel_work_sync() waits for wq tasks to complete,
it does not guarantee work tasks have started. This means that the
_stop() helper can queue and instantly cancel a wq task without
having completed the associated work. This can be observed by
tracepoint inspection of a simple "rm -f <file>; fsfreeze -f <mnt>"
test:

	xfs_destroy_inode: ... ino 0x83 ...
	xfs_inode_set_need_inactive: ... ino 0x83 ...
	xfs_inodegc_stop: ...
	...
	xfs_inodegc_start: ...
	xfs_inodegc_worker: ...
	xfs_inode_inactivating: ... ino 0x83 ...

The first few lines show that the inode is removed and need inactive
state set, but the inactivation work has not completed before the
inodegc mechanism stops. The inactivation doesn't actually occur
until the fs is unfrozen and the gc mechanism starts back up. Note
that this test requires fsfreeze to reproduce because xfs_freeze
indirectly invokes xfs_fs_statfs(), which calls xfs_inodegc_flush().

When this occurs, the workqueue try_to_grab_pending() logic first
tries to steal the pending bit, which does not succeed because the
bit has been set by queue_work_on(). Subsequently, it checks for
association of a pool workqueue from the work item under the pool
lock. This association is set at the point a work item is queued and
cleared when dequeued for processing. If the association exists, the
work item is removed from the queue and cancel_work_sync() returns
true. If the pwq association is cleared, the remove attempt assumes
the task is busy and retries (eventually returning false to the
caller after waiting for the work task to complete).

To avoid this race, we can flush each work item explicitly before
cancel. However, since the _queue_all() already schedules each
underlying work item, the workqueue level helpers are sufficient to
achieve the same ordering effect. E.g., the inodegc enabled flag
prevents scheduling any further work in the _stop() case. Use the
drain_workqueue() helper in this particular case to make the intent
a bit more self explanatory.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-01-19 14:58:26 -08:00
..
libxfs xfs: remove the XFS_IOC_{ALLOC,FREE}SP* definitions 2022-01-17 09:17:11 -08:00
scrub xfs: fix online fsck handling of v5 feature bits on secondary supers 2022-01-12 09:45:21 -08:00
Kconfig xfs: fix Kconfig asking about XFS_SUPPORT_V4 when XFS_FS=n 2020-10-16 15:34:28 -07:00
kmem.c xfs: replace kmem_alloc_large() with kvmalloc() 2021-08-09 15:57:43 -07:00
kmem.h xfs: remove kmem_zone typedef 2021-10-22 16:00:31 -07:00
Makefile
mrlock.h
xfs_acl.c overlayfs update for 5.15 2021-09-02 09:21:27 -07:00
xfs_acl.h vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
xfs_aops.c xfs: punch out data fork delalloc blocks on COW writeback failure 2021-10-22 16:04:36 -07:00
xfs_aops.h
xfs_attr_inactive.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_attr_list.c xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdown 2021-08-19 10:07:13 -07:00
xfs_bio_io.c xfs: async blkdev cache flush 2021-06-21 10:05:51 -07:00
xfs_bmap_item.c xfs: create slab caches for frequently-used deferred items 2021-10-22 16:04:36 -07:00
xfs_bmap_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_bmap_util.c xfs: kill the XFS_IOC_{ALLOC,FREE}SP* ioctls 2022-01-17 09:16:41 -08:00
xfs_bmap_util.h xfs: kill the XFS_IOC_{ALLOC,FREE}SP* ioctls 2022-01-17 09:16:41 -08:00
xfs_buf_item_recover.c xfs: check sb_meta_uuid for dabuf buffer recovery 2021-12-21 09:49:41 -08:00
xfs_buf_item.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_buf_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_buf.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_buf.h xfs: rename buffer cache index variable b_bn 2021-08-19 10:07:15 -07:00
xfs_dir2_readdir.c xfs: take the ILOCK when readdir inspects directory mapping data 2022-01-11 15:11:04 -08:00
xfs_discard.c xfs: convert mount flags to features 2021-08-19 10:07:12 -07:00
xfs_discard.h
xfs_dquot_item_recover.c xfs: replace xfs_sb_version checks with feature flag checks 2021-08-19 10:07:12 -07:00
xfs_dquot_item.c xfs: remove support for disabling quota accounting on a mounted file system 2021-08-06 11:05:36 -07:00
xfs_dquot_item.h xfs: remove support for disabling quota accounting on a mounted file system 2021-08-06 11:05:36 -07:00
xfs_dquot.c xfs: hold quota inode ILOCK_EXCL until the end of dqalloc 2022-01-06 10:43:30 -08:00
xfs_dquot.h xfs: queue inactivation immediately when quota is nearing enforcement 2021-08-09 10:52:18 -07:00
xfs_error.c xfs: sysfs: use default_groups in kobj_type 2022-01-06 10:43:30 -08:00
xfs_error.h xfs: add trace point for fs shutdown 2021-08-18 18:46:00 -07:00
xfs_export.c xfs: convert remaining mount flags to state flags 2021-08-19 10:07:13 -07:00
xfs_export.h
xfs_extent_busy.c xfs: pass perags through to the busy extent code 2021-06-02 10:48:24 +10:00
xfs_extent_busy.h xfs: pass perags through to the busy extent code 2021-06-02 10:48:24 +10:00
xfs_extfree_item.c xfs: reduce the size of struct xfs_extent_free_item 2021-10-22 16:04:36 -07:00
xfs_extfree_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_file.c xfs: kill the XFS_IOC_{ALLOC,FREE}SP* ioctls 2022-01-17 09:16:41 -08:00
xfs_filestream.c xfs: convert remaining mount flags to state flags 2021-08-19 10:07:13 -07:00
xfs_filestream.h xfs: convert mount flags to features 2021-08-19 10:07:12 -07:00
xfs_fsmap.c xfs: replace xfs_sb_version checks with feature flag checks 2021-08-19 10:07:12 -07:00
xfs_fsmap.h xfs: fix deadlock and streamline xfs_getfsmap performance 2020-10-07 08:40:29 -07:00
xfs_fsops.c xfs: convert remaining mount flags to state flags 2021-08-19 10:07:13 -07:00
xfs_fsops.h xfs: get rid of xfs_growfs_{data,log}_t 2021-02-03 09:18:50 -08:00
xfs_globals.c xfs: consolidate the eofblocks and cowblocks workers 2021-02-03 09:18:49 -08:00
xfs_health.c xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdown 2021-08-19 10:07:13 -07:00
xfs_icache.c xfs: flush inodegc workqueue tasks before cancel 2022-01-19 14:58:26 -08:00
xfs_icache.h xfs: throttle inode inactivation queuing on memory reclaim 2021-08-09 11:13:17 -07:00
xfs_icreate_item.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_icreate_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_inode_item_recover.c xfs: replace xfs_sb_version checks with feature flag checks 2021-08-19 10:07:12 -07:00
xfs_inode_item.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_inode_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_inode.c xfs: remove incorrect ASSERT in xfs_rename 2021-12-01 17:27:48 -08:00
xfs_inode.h xfs: remove xfs_inew_wait 2021-11-24 10:06:02 -08:00
xfs_ioctl32.c xfs: kill the XFS_IOC_{ALLOC,FREE}SP* ioctls 2022-01-17 09:16:41 -08:00
xfs_ioctl32.h xfs: remove unused xfs_ioctl32.h declarations 2022-01-18 10:18:36 -08:00
xfs_ioctl.c xfs: remove the XFS_IOC_{ALLOC,FREE}SP* definitions 2022-01-17 09:17:11 -08:00
xfs_ioctl.h xfs: kill the XFS_IOC_{ALLOC,FREE}SP* ioctls 2022-01-17 09:16:41 -08:00
xfs_iomap.c xfs: only set IOMAP_F_SHARED when providing a srcmap to a write 2021-08-23 17:32:51 -07:00
xfs_iomap.h
xfs_iops.c xfs: Fix comments mentioning xfs_ialloc 2021-12-21 09:49:41 -08:00
xfs_iops.h xfs: support idmapped mounts 2021-01-24 14:43:46 +01:00
xfs_itable.c xfs: replace xfs_sb_version checks with feature flag checks 2021-08-19 10:07:12 -07:00
xfs_itable.h xfs: support idmapped mounts 2021-01-24 14:43:46 +01:00
xfs_iwalk.c xfs: avoid buffer deadlocks when walking fs inodes 2021-08-09 11:13:16 -07:00
xfs_iwalk.h
xfs_linux.h xfs: async blkdev cache flush 2021-06-21 10:05:51 -07:00
xfs_log_cil.c xfs: reduce kvmalloc overhead for CIL shadow buffers 2022-01-06 10:43:30 -08:00
xfs_log_priv.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_log_recover.c xfs: Remove redundant assignment of mp 2022-01-06 10:43:30 -08:00
xfs_log.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_log.h xfs: AIL needs asynchronous CIL forcing 2021-08-16 12:09:30 -07:00
xfs_message.c
xfs_message.h once: implement DO_ONCE_LITE for non-fast-path "do once" functionality 2021-06-28 15:54:57 -07:00
xfs_mount.c xfs: only run COW extent recovery when there are no live extents 2021-12-21 09:49:41 -08:00
xfs_mount.h xfs: compute maximum AG btree height for critical reservation calculation 2021-10-19 11:45:15 -07:00
xfs_mru_cache.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_mru_cache.h
xfs_ondisk.h xfs: rename struct xfs_legacy_ictimestamp 2021-04-22 18:29:25 -07:00
xfs_pnfs.c xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdown 2021-08-19 10:07:13 -07:00
xfs_pnfs.h
xfs_pwork.c xfs: increase the default parallelism levels of pwork clients 2021-02-03 09:18:49 -08:00
xfs_pwork.h xfs: increase the default parallelism levels of pwork clients 2021-02-03 09:18:49 -08:00
xfs_qm_bhv.c xfs: replace xfs_sb_version checks with feature flag checks 2021-08-19 10:07:12 -07:00
xfs_qm_syscalls.c xfs: fix quotaoff mutex usage now that we don't support disabling it 2021-12-21 09:49:41 -08:00
xfs_qm.c xfs: remove the xfs_dqblk_t typedef 2021-10-14 09:19:33 -07:00
xfs_qm.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_quota.h xfs: queue inactivation immediately when quota is nearing enforcement 2021-08-09 10:52:18 -07:00
xfs_quotaops.c xfs: remove the active vs running quota differentiation 2021-08-06 11:05:37 -07:00
xfs_refcount_item.c xfs: create slab caches for frequently-used deferred items 2021-10-22 16:04:36 -07:00
xfs_refcount_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_reflink.c xfs: only run COW extent recovery when there are no live extents 2021-12-21 09:49:41 -08:00
xfs_reflink.h xfs: convert xfs_sb_version_has checks to use mount features 2021-08-19 10:07:14 -07:00
xfs_rmap_item.c xfs: create slab caches for frequently-used deferred items 2021-10-22 16:04:36 -07:00
xfs_rmap_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_rtalloc.c xfs: replace xfs_sb_version checks with feature flag checks 2021-08-19 10:07:12 -07:00
xfs_rtalloc.h xfs: make the record pointer passed to query_range functions const 2021-08-18 18:46:01 -07:00
xfs_stats.c xfs: periodically relog deferred intent items 2020-10-07 08:40:28 -07:00
xfs_stats.h xfs: periodically relog deferred intent items 2020-10-07 08:40:28 -07:00
xfs_super.c xfs: only run COW extent recovery when there are no live extents 2021-12-21 09:49:41 -08:00
xfs_super.h xfs: remove xfs_blkdev_issue_flush 2021-06-21 10:05:46 -07:00
xfs_symlink.c xfs: don't expose internal symlink metadata buffers to the vfs 2021-12-21 09:49:41 -08:00
xfs_symlink.h xfs: support idmapped mounts 2021-01-24 14:43:46 +01:00
xfs_sysctl.c xfs: restore speculative_cow_prealloc_lifetime sysctl 2021-02-24 10:16:08 -08:00
xfs_sysctl.h xfs: consolidate the eofblocks and cowblocks workers 2021-02-03 09:18:49 -08:00
xfs_sysfs.c xfs: sysfs: use default_groups in kobj_type 2022-01-06 10:43:30 -08:00
xfs_sysfs.h
xfs_trace.c xfs: add trace point for fs shutdown 2021-08-18 18:46:00 -07:00
xfs_trace.h xfs: prepare xfs_btree_cur for dynamic cursor heights 2021-10-19 11:45:14 -07:00
xfs_trans_ail.c xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdown 2021-08-19 10:07:13 -07:00
xfs_trans_buf.c xfs: introduce xfs_buf_daddr() 2021-08-19 10:07:14 -07:00
xfs_trans_dquot.c xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_trans_priv.h
xfs_trans.c xfs: shut down filesystem if we xfs_trans_cancel with deferred work items 2021-12-21 09:49:41 -08:00
xfs_trans.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_xattr.c xfs: prevent metadata files from being inactivated 2021-03-25 16:47:50 -07:00
xfs.h