Re: I/O hangs after resuming from suspend-to-ram

From: Martin Steigerwald
Date: Sat Aug 26 2017 - 07:25:03 EST


Hello Oleksandr,

Oleksandr Natalenko - 26.08.17, 12:48:
> Quick update: reproduced on both v4.12.7 and v4.13.0-rc6.
>
> On sobota 26. srpna 2017 12:37:29 CEST Oleksandr Natalenko wrote:
[â]
> > I've re-checked this issue with 4.12.9, and it is still there.
[â]
> > On Ãterà 22. srpna 2017 13:45:43 CEST Oleksandr Natalenko wrote:
> > > Hi.
> > >
> > > v4.12.8 kernel hangs in I/O path after resuming from suspend-to-ram. I
> > > have
> > > blk-mq enabled, tried both BFQ and mq-deadline schedulers with the same
> > > result. Soft lockup happens showing stacktraces I'm pasting below.

I did have occassional hangs on resuming from suspend-to-ram with 4.12, butâ I
am not certain that its related to I/O issues.

The hangs were gone as I tried with a kernel config from a friend that still
uses CFQ, I then adapted it to use 1000HZ, low-latency desktop and blk-mq as I
used before and also enabled optimization for the processor type in this
ThinkPad T520, and got hangs on resuming from suspend-to-ram again.

As backing out the change from 250 HZ to 1000 HZ, and from low-latency desktop
to the lesser low latency option did not help, I am now currently re-using the
config from my friend minus quite some drivers and unneeded kernel features,
but otherwise almost unchanged. I.e. back with CFQ as well. So far so good,
but it needs at least 4-5 days of additional testing to be sure.

Alsoâ when a hang happened the mouse pointer was frozen, Ctrl-Alt-F1 didnÂt
work and so onâ so it may easily be a completely different issue.

I did not see much point in reporting it so farâ as I have no idea on how to
reliably pin-point the issue. It happens once every few days, so a bisect
again is out of questions â (it is anyway for a production machine for me) â,
it appears to be a hard freeze, so no debug dataâ its one of these "you donÂt
get to debug me" hangs again. I really have no idea how to a get hold on such
complexity. I am hoping to at least pin-point the exact kernel option that
triggers this issue, but it may take weeks to do so. IÂd really love a way for
the kernel to at least to write out debug data before doing hanging
completely.

Thanks,
Martin

> > >
> > > Stacktrace shows that I/O hangs in md_super_wait(), and it means it
> > > waits
> > > for "all superblock writes that were scheduled to complete". Since there
> > > is
> > > "scheduled" word, should I also try "none" scheduler with blk-mq
> > > enabled?
> > >
> > > While I'm trying to reproduce it on a VM without much luck (it happens
> > > on
> > > my laptop rarely, like 1 out of 10 suspend-resume cycles), and also
> > > re-checking it with blk-mq disabled, by any chance is this something
> > > already known?
> > >
> > > Ideally, I'd like to reprduce it in a VM and capture vmcore.
> > >
> > > Any suggestions are welcome. Thanks.
> > >
> > > ===
> > > [ 9460.165958] INFO: task md0_raid10:225 blocked for more than 120
> > > seconds.
> > > [ 9460.165983] Not tainted 4.12.0-pf7 #1
> > > [ 9460.165989] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.165996] md0_raid10 D 0 225 2 0x00000000
> > > [ 9460.166005] Call Trace:
> > > [ 9460.166027] __schedule+0x6e7/0xcd0
> > > [ 9460.166043] schedule+0x3d/0xd0
> > > [ 9460.166067] md_super_wait+0x6e/0xa0 [md_mod]
> > > [ 9460.166130] ? wake_bit_function+0x60/0x60
> > > [ 9460.166143] write_page+0x185/0x310 [md_mod]
> > > [ 9460.166156] bitmap_update_sb+0x12f/0x140 [md_mod]
> > > [ 9460.166167] md_update_sb.part.60+0x354/0x840 [md_mod]
> > > [ 9460.166179] ? percpu_ref_switch_to_percpu+0x36/0x40
> > > [ 9460.166190] md_check_recovery+0x214/0x4b0 [md_mod]
> > > [ 9460.166201] raid10d+0x62/0x13c0 [raid10]
> > > [ 9460.166213] ? lock_timer_base+0x81/0xa0
> > > [ 9460.166222] ? try_to_del_timer_sync+0x53/0x80
> > > [ 9460.166232] ? del_timer_sync+0x39/0x40
> > > [ 9460.166246] ? schedule_timeout+0x19b/0x330
> > > [ 9460.166261] ? call_timer_fn+0x160/0x160
> > > [ 9460.166279] md_thread+0x120/0x160 [md_mod]
> > > [ 9460.166290] ? md_thread+0x120/0x160 [md_mod]
> > > [ 9460.166298] ? wake_bit_function+0x60/0x60
> > > [ 9460.166309] kthread+0x124/0x140
> > > [ 9460.166319] ? find_pers+0x70/0x70 [md_mod]
> > > [ 9460.166353] ? kthread_create_on_node+0x70/0x70
> > > [ 9460.166360] ret_from_fork+0x25/0x30
> > > [ 9460.166371] INFO: task dmcrypt_write:254 blocked for more than 120
> > > seconds. [ 9460.166376] Not tainted 4.12.0-pf7 #1
> > > [ 9460.166381] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.166386] dmcrypt_write D 0 254 2 0x00000000
> > > [ 9460.166492] Call Trace:
> > > [ 9460.166501] __schedule+0x6e7/0xcd0
> > > [ 9460.166511] schedule+0x3d/0xd0
> > > [ 9460.166522] md_write_start+0xe3/0x270 [md_mod]
> > > [ 9460.166529] ? wake_bit_function+0x60/0x60
> > > [ 9460.166538] raid10_make_request+0x3f/0x140 [raid10]
> > > [ 9460.166549] md_make_request+0xa9/0x2a0 [md_mod]
> > > [ 9460.166557] ? __schedule+0x6ef/0xcd0
> > > [ 9460.166567] generic_make_request+0x11e/0x2f0
> > > [ 9460.166578] dmcrypt_write+0x22d/0x250 [dm_crypt]
> > > [ 9460.166586] ? dmcrypt_write+0x22d/0x250 [dm_crypt]
> > > [ 9460.166596] ? wake_up_q+0x80/0x80
> > > [ 9460.166605] kthread+0x124/0x140
> > > [ 9460.166613] ? kthread+0x124/0x140
> > > [ 9460.166621] ? crypt_iv_essiv_dtr+0x70/0x70 [dm_crypt]
> > > [ 9460.166628] ? kthread_create_on_node+0x70/0x70
> > > [ 9460.166635] ret_from_fork+0x25/0x30
> > > [ 9460.166677] INFO: task konversation:7110 blocked for more than 120
> > > seconds. [ 9460.166683] Not tainted 4.12.0-pf7 #1
> > > [ 9460.166687] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.166693] konversation D 0 7110 6972 0x00000000
> > > [ 9460.166700] Call Trace:
> > > [ 9460.166709] __schedule+0x6e7/0xcd0
> > > [ 9460.166719] schedule+0x3d/0xd0
> > > [ 9460.166824] io_schedule+0x16/0x40
> > > [ 9460.166833] wait_on_page_bit+0xeb/0x130
> > > [ 9460.166841] ? page_cache_tree_insert+0xc0/0xc0
> > > [ 9460.166882] prepare_pages+0x1b5/0x1d0 [btrfs]
> > > [ 9460.166915] __btrfs_buffered_write+0x267/0x6d0 [btrfs]
> > > [ 9460.166948] btrfs_file_write_iter+0x1c1/0x500 [btrfs]
> > > [ 9460.166956] ? cp_new_stat+0x152/0x180
> > > [ 9460.166966] __vfs_write+0xe4/0x140
> > > [ 9460.166975] vfs_write+0xb1/0x1a0
> > > [ 9460.166984] SyS_write+0x55/0xc0
> > > [ 9460.166994] entry_SYSCALL_64_fastpath+0x1a/0xa5
> > > [ 9460.167001] RIP: 0033:0x7fd020f09c0d
> > > [ 9460.167006] RSP: 002b:00007ffe27e70360 EFLAGS: 00000293 ORIG_RAX:
> > > 0000000000000001
> > > [ 9460.167013] RAX: ffffffffffffffda RBX: 0000000003178840 RCX:
> > > 00007fd020f09c0d
> > > [ 9460.167019] RDX: 000000000000007d RSI: 0000000003241598 RDI:
> > > 000000000000002b
> > > [ 9460.167024] RBP: 00007fd0211c72a0 R08: 00007fd021a55010 R09:
> > > 0000000000000030
> > > [ 9460.167029] R10: 00007fd0211caad8 R11: 0000000000000293 R12:
> > > 0000000000000000
> > > [ 9460.167034] R13: 00000000013b4cef R14: 0000000000000400 R15:
> > > 0000000000000001
> > > [ 9460.167075] INFO: task akonadi_imap_re:7363 blocked for more than 120
> > > seconds.
> > > [ 9460.167080] Not tainted 4.12.0-pf7 #1
> > > [ 9460.167084] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.167089] akonadi_imap_re D 0 7363 7107 0x00000000
> > > [ 9460.167096] Call Trace:
> > > [ 9460.167105] __schedule+0x6e7/0xcd0
> > > [ 9460.167114] schedule+0x3d/0xd0
> > > [ 9460.167149] wait_for_writer+0xb1/0xe0 [btrfs]
> > > [ 9460.167157] ? wake_bit_function+0x60/0x60
> > > [ 9460.167190] btrfs_sync_log+0xe2/0xad0 [btrfs]
> > > [ 9460.167201] ? dput.part.24+0x51/0x1d0
> > > [ 9460.167210] ? dput+0x13/0x20
> > > [ 9460.167242] ? btrfs_log_dentry_safe+0x6a/0x80 [btrfs]
> > > [ 9460.167275] btrfs_sync_file+0x2f4/0x3f0 [btrfs]
> > > [ 9460.167302] ? btrfs_sync_file+0x2f4/0x3f0 [btrfs]
> > > [ 9460.167313] vfs_fsync_range+0x4b/0xb0
> > > [ 9460.167320] do_fsync+0x3d/0x70
> > > [ 9460.167327] SyS_fdatasync+0x13/0x20
> > > [ 9460.167336] entry_SYSCALL_64_fastpath+0x1a/0xa5
> > > [ 9460.167342] RIP: 0033:0x7fcdf0d7522d
> > > [ 9460.167348] RSP: 002b:00007ffdcb64e9a0 EFLAGS: 00000293 ORIG_RAX:
> > > 000000000000004b
> > > [ 9460.167355] RAX: ffffffffffffffda RBX: 0000007b8c7c9f80 RCX:
> > > 00007fcdf0d7522d
> > > [ 9460.167361] RDX: 0000000000000023 RSI: 0000007b8c7ca228 RDI:
> > > 0000000000000010
> > > [ 9460.167366] RBP: 0000000000000001 R08: 0000007b8c7c9270 R09:
> > > 000000000000002f
> > > [ 9460.167371] R10: 0000007b8c7c9830 R11: 0000000000000293 R12:
> > > 0000007b8c7b88f0
> > > [ 9460.167376] R13: 0000000000000000 R14: 0000000000000010 R15:
> > > 0000007b8c7b66b0
> > > [ 9460.167387] INFO: task akonadi_maildis:7366 blocked for more than 120
> > > seconds.
> > > [ 9460.167492] Not tainted 4.12.0-pf7 #1
> > > [ 9460.167496] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.167501] akonadi_maildis D 0 7366 7107 0x00000000
> > > [ 9460.167507] Call Trace:
> > > [ 9460.167516] __schedule+0x6e7/0xcd0
> > > [ 9460.167525] schedule+0x3d/0xd0
> > > [ 9460.167557] wait_log_commit+0xd6/0x100 [btrfs]
> > > [ 9460.167564] ? wake_bit_function+0x60/0x60
> > > [ 9460.167593] btrfs_sync_log+0x13e/0xad0 [btrfs]
> > > [ 9460.167603] ? dput.part.24+0x51/0x1d0
> > > [ 9460.167611] ? dput+0x13/0x20
> > > [ 9460.167640] ? btrfs_log_dentry_safe+0x6a/0x80 [btrfs]
> > > [ 9460.167670] btrfs_sync_file+0x2f4/0x3f0 [btrfs]
> > > [ 9460.167696] ? btrfs_sync_file+0x2f4/0x3f0 [btrfs]
> > > [ 9460.167705] vfs_fsync_range+0x4b/0xb0
> > > [ 9460.167712] do_fsync+0x3d/0x70
> > > [ 9460.167718] SyS_fdatasync+0x13/0x20
> > > [ 9460.167727] entry_SYSCALL_64_fastpath+0x1a/0xa5
> > > [ 9460.167733] RIP: 0033:0x7ff91da0822d
> > > [ 9460.167737] RSP: 002b:00007ffdbded6fb0 EFLAGS: 00000293 ORIG_RAX:
> > > 000000000000004b
> > > [ 9460.167744] RAX: ffffffffffffffda RBX: 000000841e8cc480 RCX:
> > > 00007ff91da0822d
> > > [ 9460.167749] RDX: 0000000000000028 RSI: 000000841e902608 RDI:
> > > 000000000000000f
> > > [ 9460.167754] RBP: 0000000000000001 R08: 000000841e8aff00 R09:
> > > 000000000000002f
> > > [ 9460.167760] R10: 000000841e91a1d0 R11: 0000000000000293 R12:
> > > 000000841e910cc0
> > > [ 9460.167764] R13: 0000000000000000 R14: 000000000000000f R15:
> > > 000000841e9165c0
> > > [ 9460.167786] INFO: task chromium:7600 blocked for more than 120
> > > seconds.
> > > [ 9460.167791] Not tainted 4.12.0-pf7 #1
> > > [ 9460.167796] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.167800] chromium D 0 7600 7020 0x00000000
> > > [ 9460.167807] Call Trace:
> > > [ 9460.167815] __schedule+0x6e7/0xcd0
> > > [ 9460.167824] schedule+0x3d/0xd0
> > > [ 9460.167831] io_schedule+0x16/0x40
> > > [ 9460.167838] wait_on_page_bit+0xeb/0x130
> > > [ 9460.167847] ? page_cache_tree_insert+0xc0/0xc0
> > > [ 9460.167879] btrfs_page_mkwrite+0x1bf/0x400 [btrfs]
> > > [ 9460.167889] do_page_mkwrite+0x31/0x90
> > > [ 9460.167896] ? current_time+0x38/0x70
> > > [ 9460.167905] do_wp_page+0x200/0x4b0
> > > [ 9460.167911] ? file_update_time+0x60/0x110
> > > [ 9460.167920] __handle_mm_fault+0x832/0xd50
> > > [ 9460.167930] handle_mm_fault+0xde/0x220
> > > [ 9460.167938] __do_page_fault+0x24d/0x510
> > > [ 9460.167946] do_page_fault+0x22/0x30
> > > [ 9460.167954] page_fault+0x28/0x30
> > > [ 9460.167959] RIP: 0033:0x64de23cd9c
> > > [ 9460.167964] RSP: 002b:00007ffdfd4ad4c0 EFLAGS: 00010202
> > > [ 9460.167970] RAX: 00007f80a51b9d58 RBX: 0000398cef048700 RCX:
> > > 0000398ce8da6510
> > > [ 9460.167982] RDX: 0000000000000006 RSI: 0000000000000000 RDI:
> > > 0000398cef048700
> > > [ 9460.167988] RBP: 0000000000000005 R08: 0000000000000000 R09:
> > > 0000000000000000
> > > [ 9460.167993] R10: 00007ffdfd4acdc0 R11: 0000000000000000 R12:
> > > 0000000000000001
> > > [ 9460.168000] R13: 0000000000000005 R14: 00007ffdfd4ad908 R15:
> > > 0000000000000000
> > > [ 9460.168014] INFO: task BrowserBlocking:7639 blocked for more than 120
> > > seconds.
> > > [ 9460.168019] Not tainted 4.12.0-pf7 #1
> > > [ 9460.168024] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.168028] BrowserBlocking D 0 7639 7020 0x00000000
> > > [ 9460.168035] Call Trace:
> > > [ 9460.168044] __schedule+0x6e7/0xcd0
> > > [ 9460.168054] schedule+0x3d/0xd0
> > > [ 9460.168061] io_schedule+0x16/0x40
> > > [ 9460.168068] wait_on_page_bit_common+0xe3/0x180
> > > [ 9460.168076] ? page_cache_tree_insert+0xc0/0xc0
> > > [ 9460.168083] __filemap_fdatawait_range+0x12a/0x1a0
> > > [ 9460.168093] filemap_fdatawait_range+0x14/0x30
> > > [ 9460.168128] btrfs_wait_ordered_range+0x6b/0x110 [btrfs]
> > > [ 9460.168157] ? btrfs_fdatawrite_range+0x20/0x50 [btrfs]
> > > [ 9460.168186] btrfs_sync_file+0x17c/0x3f0 [btrfs]
> > > [ 9460.168195] vfs_fsync_range+0x4b/0xb0
> > > [ 9460.168202] do_fsync+0x3d/0x70
> > > [ 9460.168209] SyS_fdatasync+0x13/0x20
> > > [ 9460.168218] entry_SYSCALL_64_fastpath+0x1a/0xa5
> > > [ 9460.168223] RIP: 0033:0x7f80b8fcd22d
> > > [ 9460.168228] RSP: 002b:00007f808c8b7680 EFLAGS: 00000293 ORIG_RAX:
> > > 000000000000004b
> > > [ 9460.168235] RAX: ffffffffffffffda RBX: 00007f808c8b7670 RCX:
> > > 00007f80b8fcd22d
> > > [ 9460.168240] RDX: 00000000000019bc RSI: 0000398cef877800 RDI:
> > > 0000000000000119
> > > [ 9460.168246] RBP: 0000000000000119 R08: 0000000000000037 R09:
> > > 0000398ce88693c0
> > > [ 9460.168251] R10: 0000000000000000 R11: 0000000000000293 R12:
> > > 00007f808c8b77d8
> > > [ 9460.168257] R13: 0000398ceb6cf820 R14: 00000000000019bc R15:
> > > 0000398cef877800
> > > [ 9460.168267] INFO: task Chrome_SyncThre:7867 blocked for more than 120
> > > seconds.
> > > [ 9460.168272] Not tainted 4.12.0-pf7 #1
> > > [ 9460.168277] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.168282] Chrome_SyncThre D 0 7867 7020 0x00000000
> > > [ 9460.168289] Call Trace:
> > > [ 9460.168297] __schedule+0x6e7/0xcd0
> > > [ 9460.168306] schedule+0x3d/0xd0
> > > [ 9460.168338] wait_ordered_extents.isra.22.constprop.26+0x354/0x3d0
> > > [btrfs] [ 9460.168348] ? wake_bit_function+0x60/0x60
> > > [ 9460.168377] btrfs_log_changed_extents+0x28a/0x620 [btrfs]
> > > [ 9460.168412] ? release_extent_buffer+0x98/0xb0 [btrfs]
> > > [ 9460.168444] btrfs_log_inode+0x97e/0x1140 [btrfs]
> > > [ 9460.168668] btrfs_log_inode_parent+0x277/0xa30 [btrfs]
> > > [ 9460.168676] ? touch_atime+0xc1/0xd0
> > > [ 9460.168686] ? refcount_inc+0x9/0x30
> > > [ 9460.168719] ? join_transaction+0x122/0x450 [btrfs]
> > > [ 9460.168750] btrfs_log_dentry_safe+0x60/0x80 [btrfs]
> > > [ 9460.168779] btrfs_sync_file+0x2b3/0x3f0 [btrfs]
> > > [ 9460.168787] vfs_fsync_range+0x4b/0xb0
> > > [ 9460.168794] do_fsync+0x3d/0x70
> > > [ 9460.168801] SyS_fdatasync+0x13/0x20
> > > [ 9460.168810] entry_SYSCALL_64_fastpath+0x1a/0xa5
> > > [ 9460.168815] RIP: 0033:0x7f80b8fcd22d
> > > [ 9460.168819] RSP: 002b:00007f80804e1720 EFLAGS: 00000293 ORIG_RAX:
> > > 000000000000004b
> > > [ 9460.168826] RAX: ffffffffffffffda RBX: 0000000000008000 RCX:
> > > 00007f80b8fcd22d
> > > [ 9460.168830] RDX: 0000000000000001 RSI: 0000000000000002 RDI:
> > > 00000000000000fb
> > > [ 9460.168835] RBP: 0000398ce9e33000 R08: 0000398ced562800 R09:
> > > 0000000000000001
> > > [ 9460.168840] R10: 0000000000018400 R11: 0000000000000293 R12:
> > > 00000000004b0000
> > > [ 9460.168845] R13: 0000398ceac2ac78 R14: 0000398ce9e3b038 R15:
> > > 0000398ceb9a1048
> > > [ 9460.168854] INFO: task BrowserBlocking:8011 blocked for more than 120
> > > seconds.
> > > [ 9460.168858] Not tainted 4.12.0-pf7 #1
> > > [ 9460.168863] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.168867] BrowserBlocking D 0 8011 7020 0x00000000
> > > [ 9460.168873] Call Trace:
> > > [ 9460.168882] __schedule+0x6e7/0xcd0
> > > [ 9460.168892] schedule+0x3d/0xd0
> > > [ 9460.168898] io_schedule+0x16/0x40
> > > [ 9460.168905] wait_on_page_bit_common+0xe3/0x180
> > > [ 9460.168912] ? page_cache_tree_insert+0xc0/0xc0
> > > [ 9460.168919] __filemap_fdatawait_range+0x12a/0x1a0
> > > [ 9460.168929] filemap_fdatawait_range+0x14/0x30
> > > [ 9460.168961] btrfs_wait_ordered_range+0x6b/0x110 [btrfs]
> > > [ 9460.168989] ? btrfs_fdatawrite_range+0x20/0x50 [btrfs]
> > > [ 9460.169015] btrfs_sync_file+0x17c/0x3f0 [btrfs]
> > > [ 9460.169025] vfs_fsync_range+0x4b/0xb0
> > > [ 9460.169033] do_fsync+0x3d/0x70
> > > [ 9460.169040] SyS_fdatasync+0x13/0x20
> > > [ 9460.169050] entry_SYSCALL_64_fastpath+0x1a/0xa5
> > > [ 9460.169055] RIP: 0033:0x7f80b8fcd22d
> > > [ 9460.169060] RSP: 002b:00007f807d5f1680 EFLAGS: 00000293 ORIG_RAX:
> > > 000000000000004b
> > > [ 9460.169066] RAX: ffffffffffffffda RBX: 00007f807d5f1670 RCX:
> > > 00007f80b8fcd22d
> > > [ 9460.169073] RDX: 000000000001f95c RSI: 0000398cece75000 RDI:
> > > 000000000000011d
> > > [ 9460.169078] RBP: 000000000000011d R08: 000000000000003f R09:
> > > 0000398ce8870200
> > > [ 9460.169083] R10: 0000000000000000 R11: 0000000000000293 R12:
> > > 00007f807d5f17d8
> > > [ 9460.169088] R13: 0000398ceafb9160 R14: 000000000001f95c R15:
> > > 0000398cece75000
> > > [ 9460.169098] INFO: task TaskSchedulerBa:9603 blocked for more than 120
> > > seconds.
> > > [ 9460.169103] Not tainted 4.12.0-pf7 #1
> > > [ 9460.169108] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > > disables
> > > this message.
> > > [ 9460.169113] TaskSchedulerBa D 0 9603 7020 0x00000000
> > > [ 9460.169120] Call Trace:
> > > [ 9460.169128] __schedule+0x6e7/0xcd0
> > > [ 9460.169138] schedule+0x3d/0xd0
> > > [ 9460.169166] wait_ordered_extents.isra.22.constprop.26+0x354/0x3d0
> > > [btrfs] [ 9460.169175] ? wake_bit_function+0x60/0x60
> > > [ 9460.169204] btrfs_log_changed_extents+0x28a/0x620 [btrfs]
> > > [ 9460.169237] ? release_extent_buffer+0x98/0xb0 [btrfs]
> > > [ 9460.169265] btrfs_log_inode+0x97e/0x1140 [btrfs]
> > > [ 9460.169278] ? __set_page_dirty_nobuffers+0x117/0x150
> > > [ 9460.169310] ? btree_set_page_dirty+0xe/0x10 [btrfs]
> > > [ 9460.169346] ? set_extent_buffer_dirty+0x7b/0xb0 [btrfs]
> > > [ 9460.169378] btrfs_log_inode_parent+0x277/0xa30 [btrfs]
> > > [ 9460.169386] ? touch_atime+0xc1/0xd0
> > > [ 9460.169395] ? refcount_inc+0x9/0x30
> > > [ 9460.169427] ? join_transaction+0x122/0x450 [btrfs]
> > > [ 9460.169457] btrfs_log_dentry_safe+0x60/0x80 [btrfs]
> > > [ 9460.169490] btrfs_sync_file+0x2b3/0x3f0 [btrfs]
> > > [ 9460.169498] vfs_fsync_range+0x4b/0xb0
> > > [ 9460.169505] do_fsync+0x3d/0x70
> > > [ 9460.169512] SyS_fdatasync+0x13/0x20
> > > [ 9460.169522] entry_SYSCALL_64_fastpath+0x1a/0xa5
> > > [ 9460.169527] RIP: 0033:0x7f80b8fcd22d
> > > [ 9460.169532] RSP: 002b:00007f80777ea2c0 EFLAGS: 00000293 ORIG_RAX:
> > > 000000000000004b
> > > [ 9460.169541] RAX: ffffffffffffffda RBX: 0000398ce9546d90 RCX:
> > > 00007f80b8fcd22d
> > > [ 9460.169546] RDX: 0000000000000001 RSI: 0000000000000002 RDI:
> > > 0000000000000117
> > > [ 9460.169552] RBP: 0000000000000200 R08: 0000398ced6459c0 R09:
> > > 0000000000000001
> > > [ 9460.169557] R10: 000000000000e400 R11: 0000000000000293 R12:
> > > 0000000000000001
> > > [ 9460.169562] R13: 0000000000000015 R14: 0000000000000200 R15:
> > > 0000398ce9b50d80
> > > ===


--
Martin