linux/fs/xfs
Darrick J. Wong 5a605fd6cb xfs: recalculate free rt extents after log recovery
I've been observing periodic corruption reports from xfs_scrub involving
the free rt extent counter (frextents) while running xfs/141.  That test
uses an error injection knob to induce a torn write to the log, and an
arbitrary number of recovery mounts, frextents will count fewer free rt
extents than can be found the rtbitmap.

The root cause of the problem is a combination of the misuse of
sb_frextents in the incore mount to reflect both incore reservations
made by running transactions as well as the actual count of free rt
extents on disk.  The following sequence can reproduce the undercount:

Thread 1			Thread 2
xfs_trans_alloc(rtextents=3)
xfs_mod_frextents(-3)
<blocks>
				xfs_attr_set()
				xfs_bmap_attr_addfork()
				xfs_add_attr2()
				xfs_log_sb()
				xfs_sb_to_disk()
				xfs_trans_commit()
<log flushed to disk>
<log goes down>

Note that thread 1 subtracts 3 from sb_frextents even though it never
commits to using that space.  Thread 2 writes the undercounted value to
the ondisk superblock and logs it to the xattr transaction, which is
then flushed to disk.  At next mount, log recovery will find the logged
superblock and write that back into the filesystem.  At the end of log
recovery, we reread the superblock and install the recovered
undercounted frextents value into the incore superblock.  From that
point on, we've effectively leaked thread 1's transaction reservation.

The correct fix for this is to separate the incore reservation from the
ondisk usage, but that's a matter for the next patch.  Because the
kernel has been logging superblocks with undercounted frextents for a
very long time and we don't demand that sysadmins run xfs_repair after a
crash, fix the undercount by recomputing frextents after log recovery.

Gating this on log recovery is a reasonable balance (I think) between
correcting the problem and slowing down every mount attempt.  Note that
xfs_repair will fix undercounted frextents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-12 06:49:42 +10:00
..
libxfs xfs: pass explicit mount pointer to rtalloc query functions 2022-04-12 06:49:41 +10:00
scrub xfs: pass explicit mount pointer to rtalloc query functions 2022-04-12 06:49:41 +10:00
Kconfig
kmem.c mm: introduce memalloc_retry_wait() 2022-01-15 16:30:29 +02:00
kmem.h xfs: remove kmem_zone typedef 2021-10-22 16:00:31 -07:00
Makefile
mrlock.h
xfs.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 fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio 2022-03-16 13:37:05 -04:00
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 Bug fixes for 5.18: 2022-04-01 19:30:44 -07:00
xfs_bmap_item.c xfs: log items should have a xlog pointer, not a mount 2022-03-20 08:59:49 -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: set prealloc flag in xfs_alloc_file_space() 2022-02-01 14:14:48 -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.c New code for 5.18: 2022-03-24 18:28:01 -07:00
xfs_buf.h dax: return the partition offset from fs_dax_get_by_bdev 2021-12-04 08:58:54 -08:00
xfs_buf_item.c xfs: log items should have a xlog pointer, not a mount 2022-03-20 08:59:49 -07:00
xfs_buf_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_buf_item_recover.c xfs: check sb_meta_uuid for dabuf buffer recovery 2021-12-21 09:49:41 -08:00
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.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_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_item_recover.c xfs: replace xfs_sb_version checks with feature flag checks 2021-08-19 10:07:12 -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: log items should have a xlog pointer, not a mount 2022-03-20 08:59:49 -07:00
xfs_extfree_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_file.c xfs: Use generic_file_open() 2022-04-12 06:49:40 +10:00
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: pass explicit mount pointer to rtalloc query functions 2022-04-12 06:49:41 +10:00
xfs_fsmap.h
xfs_fsops.c xfs: xfs_do_force_shutdown needs to block racing shutdowns 2022-03-29 18:22:01 -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 Bug fixes for 5.18: 2022-04-01 19:30:44 -07:00
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.c xfs: aborting inodes on shutdown may need buffer lock 2022-03-29 18:21:59 -07:00
xfs_inode.h xfs: constify the name argument to various directory functions 2022-03-14 10:23:17 -07:00
xfs_inode_item.c xfs: aborting inodes on shutdown may need buffer lock 2022-03-29 18:21:59 -07:00
xfs_inode_item.h xfs: aborting inodes on shutdown may need buffer lock 2022-03-29 18:21:59 -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_ioctl.c xfs: don't generate selinux audit messages for capability testing 2022-03-09 10:32:06 -08:00
xfs_ioctl.h xfs: kill the XFS_IOC_{ALLOC,FREE}SP* ioctls 2022-01-17 09:16:41 -08:00
xfs_ioctl32.c x86: Remove toolchain check for X32 ABI capability 2022-03-15 10:32:48 +01:00
xfs_ioctl32.h xfs: remove unused xfs_ioctl32.h declarations 2022-01-18 10:18:36 -08:00
xfs_iomap.c fsdax: shift partition offset handling into the file systems 2021-12-04 08:58:54 -08:00
xfs_iomap.h iomap: add a IOMAP_DAX flag 2021-12-04 08:58:53 -08:00
xfs_iops.c xfs: refactor user/group quota chown in xfs_setattr_nonsize 2022-03-14 10:23:17 -07:00
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: drop async cache flushes from CIL commits. 2022-03-29 18:22:02 -07:00
xfs_log.c Bug fixes for 5.18: 2022-04-01 19:30:44 -07:00
xfs_log.h xfs: AIL needs asynchronous CIL forcing 2021-08-16 12:09:30 -07:00
xfs_log_cil.c xfs: drop async cache flushes from CIL commits. 2022-03-29 18:22:02 -07:00
xfs_log_priv.h xfs: drop async cache flushes from CIL commits. 2022-03-29 18:22:02 -07:00
xfs_log_recover.c xfs: log shutdown triggers should only shut down the log 2022-03-29 18:22:01 -07:00
xfs_message.c xfs: Add XFS messages to printk index 2022-04-11 13:06:39 +10:00
xfs_message.h xfs: Add XFS messages to printk index 2022-04-11 13:06:39 +10:00
xfs_mount.c xfs: recalculate free rt extents after log recovery 2022-04-12 06:49:42 +10:00
xfs_mount.h xfs: don't include bnobt blocks when reserving free block pool 2022-03-28 08:38:43 -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: use setattr_copy to set vfs inode attributes 2022-03-14 10:23:16 -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.c xfs: xfs_is_shutdown vs xlog_is_shutdown cage fight 2022-03-20 08:59:50 -07:00
xfs_qm.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
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_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: log items should have a xlog pointer, not a mount 2022-03-20 08:59:49 -07:00
xfs_refcount_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_reflink.c xfs: add missing cmap->br_state = XFS_EXT_NORM update 2022-03-09 10:32:06 -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: log items should have a xlog pointer, not a mount 2022-03-20 08:59:49 -07:00
xfs_rmap_item.h xfs: rename _zone variables to _cache 2021-10-22 16:04:20 -07:00
xfs_rtalloc.c xfs: recalculate free rt extents after log recovery 2022-04-12 06:49:42 +10:00
xfs_rtalloc.h xfs: recalculate free rt extents after log recovery 2022-04-12 06:49:42 +10:00
xfs_stats.c
xfs_stats.h
xfs_super.c xfs: don't report reserved bnobt space as available 2022-03-28 08:39:10 -07:00
xfs_super.h xfs: remove xfs_blkdev_issue_flush 2021-06-21 10:05:46 -07:00
xfs_symlink.c New code for 5.17: 2022-01-11 15:01:50 -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: log items should have a xlog pointer, not a mount 2022-03-20 08:59:49 -07:00
xfs_trans.c xfs: xfs_trans_commit() path must check for log shutdown 2022-03-29 18:22:01 -07:00
xfs_trans.h xfs: log items should have a xlog pointer, not a mount 2022-03-20 08:59:49 -07:00
xfs_trans_ail.c xfs: log shutdown triggers should only shut down the log 2022-03-29 18:22:01 -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: AIL should be log centric 2022-03-20 08:59:49 -07:00
xfs_xattr.c xfs: prevent metadata files from being inactivated 2021-03-25 16:47:50 -07:00