The oops:
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306142] INFO: task kworker/u24:1:9703
blocked for more than 120 seconds.
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306176] Tainted: P O
4.4.0-131-generic #157-Ubuntu
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306204] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306235] kworker/u24:1 D
880038b1f858 0 9703 2 0x
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306245] Workqueue: writeback wb_workfn
(flush-zfs-2)
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306248] 880038b1f858
2980c1b4a2885446 88085b6b8e00 88085496c600
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306251] 880038b2
88085f2572c0 7fff 880038b1f9c8
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306254] 8184f8e0
880038b1f870 8184f0e5
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306257] Call Trace:
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306266] [] ?
bit_wait+0x60/0x60
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306270] []
schedule+0x35/0x80
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306273] []
schedule_timeout+0x1b6/0x270
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306330] [] ?
rrm_exit+0x48/0x80 [zfs]
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306336] [] ?
ktime_get+0x3e/0xb0
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306340] [] ?
bit_wait+0x60/0x60
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306343] []
io_schedule_timeout+0xa4/0x110
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306347] []
bit_wait_io+0x1b/0x70
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306350] []
__wait_on_bit_lock+0x50/0xb0
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306354] []
__lock_page+0xbb/0xe0
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306359] [] ?
autoremove_wake_function+0x40/0x40
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306364] []
write_cache_pages+0x2e0/0x510
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306409] [] ?
zpl_write_common_iovec+0xe0/0xe0 [zfs]
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306413] [] ?
mutex_lock+0x12/0x30
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306448] [] ?
rrw_exit+0x60/0x150 [zfs]
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306492] []
zpl_writepages+0x94/0x170 [zfs]
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306495] []
do_writepages+0x21/0x30
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306499] []
__writeback_single_inode+0x45/0x350
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306503] []
writeback_sb_inodes+0x262/0x600
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306506] []
__writeback_inodes_wb+0x8c/0xc0
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306510] []
wb_writeback+0x259/0x310
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306514] []
wb_workfn+0x19a/0x3a0
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306518] []
process_one_work+0x16b/0x490
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306522] []
worker_thread+0x4b/0x4d0
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306525] [] ?
process_one_work+0x490/0x490
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306529] []
kthread+0xe7/0x100
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306532] [] ?
kthread_create_on_node+0x1e0/0x1e0
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306535] []
ret_from_fork+0x55/0x80
Aug 7 16:47:42 wedgeamb kernel: [ 2640.306538] [] ?
kthread_create_on_node+0x1e0/0x1e0
** Description changed:
After restoring a snapshot on a running container a hung task task oops
trace gets logged for flush-zfs.
The command run was:
% lxc restore wedgeiq foo1
If the container is not running restoring seems less likely to cause the
hung task.
ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-generic 4.4.0.131.137
ProcVersionSignature: Ubuntu 4.4.0-131.157-generic 4.4.134
Uname: Linux 4.4.0-131-generic x86_64
NonfreeKernelModules: zfs zunicode zcommon znvpair zavl
AlsaDevices:
- total 0
- crw-rw 1 root audio 116, 1 Aug 7 16:03 seq
- crw-rw 1 root audio 116, 33 Aug 7 16:03 timer
+ total 0
+ crw-rw 1 root audio 116, 1 Aug 7 16:03 seq
+ crw-rw 1 root audio 116, 33 Aug 7 16:03 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq',
'/dev/snd/timer'] failed with exit code 1:
Date: Tue Aug 7 16:36:34 2018
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lsusb:
- Bus 001 Device 002: ID 8087:8000 Intel Corp.
- Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
- Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
- Bus 002 Device 002: ID 046d:c31c Logitech, Inc. Keyboard K120
- Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
+ Bus 001 Device 002: ID 8087:8000 Intel Corp.
+ Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
+ Bus 003 Device 001: ID 1d6b:0003 Lin