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| author |  Junxiao Bi <junxiao.bi@oracle.com>
| 2020-07-14 16:10:26 -0700 |
|---|---|---|
| committer |  Song Liu <songliubraving@fb.com>
| 2020-07-14 22:58:51 -0700 |
| commit | e1a86dbbbd6a77f73c3d099030495fa31f181e2f (patch) | |
| tree | 1289eb9f1851f4d91b82563fb54c2be5111d28fe /drivers/md/raid5-cache.c | |
| parent | md: improve io stats accounting (diff) | |
| download | linux-e1a86dbbbd6a77f73c3d099030495fa31f181e2f.tar.gz linux-e1a86dbbbd6a77f73c3d099030495fa31f181e2f.tar.bz2 linux-e1a86dbbbd6a77f73c3d099030495fa31f181e2f.zip | |
md: fix deadlock causing by sysfs_notify
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.
PID: 40430 TASK: ffff8ee9c8c65c40 CPU: 29 COMMAND: "probe_file"
#0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
#1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
#2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
#3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
#4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
#5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
#6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
#7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
#8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
#9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
#10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
#11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
#12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
#13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
#14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
#15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
#16 [ffffb87c4df37958] new_slab at ffffffff9a251430
#17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
#18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
#19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
#20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
#21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
#22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
#23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
#24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
#25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
#26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
#27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
#28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
#29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
#30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
#31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
#32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
#33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
RIP: 00007f617a5f2905 RSP: 00007f607334f838 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 00007f6064044b20 RCX: 00007f617a5f2905
RDX: 00007f6064044b20 RSI: 00007f6064044b20 RDI: 00007f6064005890
RBP: 00007f6064044aa0 R8: 0000000000000030 R9: 000000000000011c
R10: 0000000000000013 R11: 0000000000000246 R12: 00007f606417e6d0
R13: 00007f6064044aa0 R14: 00007f6064044b10 R15: 00000000ffffffff
ORIG_RAX: 0000000000000006 CS: 0033 SS: 002b
PID: 927 TASK: ffff8f15ac5dbd80 CPU: 42 COMMAND: "md127_raid1"
#0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
#1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
#2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
#3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
#4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
#5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
#6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
#7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
#8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
#9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
#10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
#11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
#12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
#13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
#14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Diffstat (limited to 'drivers/md/raid5-cache.c')
0 files changed, 0 insertions, 0 deletions