Re: Many processes end up in uninterruptible sleep accessing cifs mounts

[Pavel Shilovsky <piastryyy@gmail.com>]

Martijn, thanks for the traces. This is a deadlock as mentioned by Aurelien:

[36247.368103] INFO: task puppet:3836 blocked for more than 120 seconds.
[36247.368119]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
[36247.368135] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[36247.368158] puppet          D    0  3836    541 0x00000000
[36247.368159] Call Trace:
[36247.368161]  ? __schedule+0x338/0x850
[36247.368163]  schedule+0x3c/0x90
[36247.368164]  schedule_preempt_disabled+0x14/0x20
[36247.368165]  __mutex_lock.isra.7+0x19f/0x540
[36247.368166]  ? __switch_to_asm+0x34/0x70
[36247.368167]  ? __switch_to_asm+0x40/0x70
[36247.368169]  ? try_module_get+0x68/0x100
[36247.368178]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
[36247.368186]  smb2_reconnect+0x1d7/0x4b0 [cifs]
[36247.368188]  ? _raw_spin_unlock_irq+0x1d/0x30
[36247.368189]  ? finish_task_switch+0x7d/0x290
[36247.368190]  ? __switch_to_asm+0x40/0x70
[36247.368198]  smb2_plain_req_init+0x30/0x240 [cifs]
[36247.368199]  ? _raw_spin_lock_irqsave+0x25/0x50
[36247.368208]  SMB2_open_init+0x6d/0x7c0 [cifs]
[36247.368209]  ? _raw_spin_lock+0x13/0x30
[36247.368218]  ? cifs_mid_q_entry_release+0x15/0x40 [cifs]
[36247.368227]  ? SMB2_open+0x150/0x520 [cifs]
[36247.368235]  SMB2_open+0x150/0x520 [cifs]
[36247.368238]  ? sched_clock+0x5/0x10
[36247.368247]  ? open_shroot+0x12f/0x200 [cifs]
[36247.368255]  open_shroot+0x12f/0x200 [cifs]
[36247.368258]  ? __follow_mount_rcu.isra.31+0x3c/0xf0
[36247.368267]  smb2_query_path_info+0x93/0x220 [cifs]
[36247.368269]  ? walk_component+0x48/0x360
[36247.368278]  cifs_get_inode_info+0x580/0xb10 [cifs]
[36247.368286]  ? filename_lookup+0xf8/0x1a0
[36247.368294]  ? build_path_from_dentry_optional_prefix+0x1e9/0x440 [cifs]
[36247.368303]  cifs_revalidate_dentry_attr+0xdc/0x3e0 [cifs]
[36247.368311]  cifs_getattr+0x5b/0x1b0 [cifs]
[36247.368313]  vfs_statx+0x89/0xe0
[36247.368315]  __do_sys_newlstat+0x39/0x70
[36247.368318]  do_syscall_64+0x55/0x100
[36247.368320]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[36247.368321] RIP: 0033:0x7f562d3a0335
[36247.368323] Code: Bad RIP value.

This looks urgent to fix - we have a parallel thread with the similar
problem observed on 5.1 kernel. In order to fix it we need to drop
open shroot mutex before going into SMB2_open_init and other PDU
functions.

You can try to work around this by specifying "nohandlecache" mount option.

--
Best regards,
Pavel Shilovsky

сб, 6 июл. 2019 г. в 06:05, Steve French <smfrench@gmail.com>:
>
> Are we sure this isn't something really simple like the server IP
> address changing?  Remember in 5.0 kernel (also updated cifs-utils)
> the code to allow failover when server's IP address changes was added.
>
> On Sat, Jul 6, 2019 at 6:12 AM Martijn de Gouw
> <martijn.de.gouw@prodrive-technologies.com> wrote:
> >
> > Hi Pavel,
> >
> > On 04-07-2019 23:34, Pavel Shilovsky wrote:
> > > Hi Martijn,
> > >
> > > Thanks for reporting the problem. Have you tried v5.1.5 kernel and
> > > above? That one has many reconnect fixes. If yes, could you please
> > > provide the kernel stack / panic traces when running new versions of
> > > the kernel?
> >
> > I can try to run them for a while on a less critical server. But even if that machine runs fine, there is not really a guarantee the cifs issue we have right now is solved for our critical machines, causing me to be very hesitated to upgrade those.
> >
> > Btw, here is another kernel dump, generated today. Please note that on this machine the cifs mounts are not really used, all 'action'
> > performed on these mounts is the check if they are still mounted (by puppet).
> >
> >
> > [36247.367572] INFO: task node_exporter:3567 blocked for more than 120 seconds.
> > [36247.367613]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36247.367630] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36247.367648] node_exporter   D    0  3567      1 0x00000000
> > [36247.367650] Call Trace:
> > [36247.367668]  ? __schedule+0x338/0x850
> > [36247.367671]  ? preempt_count_add+0x67/0xb0
> > [36247.367673]  schedule+0x3c/0x90
> > [36247.367675]  schedule_preempt_disabled+0x14/0x20
> > [36247.367676]  __mutex_lock.isra.7+0x19f/0x540
> > [36247.367680]  ? try_module_get+0x68/0x100
> > [36247.367792]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36247.367803]  smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36247.367824]  smb2_plain_req_init+0x30/0x240 [cifs]
> > [36247.367826]  ? __switch_to_asm+0x34/0x70
> > [36247.367827]  ? __switch_to_asm+0x40/0x70
> > [36247.367836]  SMB2_open_init+0x6d/0x7c0 [cifs]
> > [36247.367846]  ? smb2_queryfs+0x13d/0x350 [cifs]
> > [36247.367848]  ? lookup_fast+0xc8/0x2e0
> > [36247.367857]  smb2_queryfs+0x13d/0x350 [cifs]
> > [36247.367861]  ? lookup_fast+0xc8/0x2e0
> > [36247.367863]  ? ___cache_free+0x31/0x2e0
> > [36247.367865]  ? terminate_walk+0x93/0x100
> > [36247.367873]  ? cifs_statfs+0xad/0x300 [cifs]
> > [36247.367880]  cifs_statfs+0xad/0x300 [cifs]
> > [36247.367894]  statfs_by_dentry+0x6a/0x90
> > [36247.367895]  vfs_statfs+0x16/0xc0
> > [36247.367897]  user_statfs+0x50/0xa0
> > [36247.367898]  __do_sys_statfs+0x20/0x50
> > [36247.367902]  do_syscall_64+0x55/0x100
> > [36247.367903]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > [36247.367905] RIP: 0033:0x4a5c20
> > [36247.367936] Code: Bad RIP value.
> > [36247.367937] RSP: 002b:000000c0003ef490 EFLAGS: 00000206 ORIG_RAX: 0000000000000089
> > [36247.367938] RAX: ffffffffffffffda RBX: 000000c00002a000 RCX: 00000000004a5c20
> > [36247.367939] RDX: 0000000000000000 RSI: 000000c0003ef5c0 RDI: 000000c0004510e0
> > [36247.367940] RBP: 000000c0003ef4f0 R08: 0000000000000000 R09: 0000000000000000
> > [36247.367940] R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
> > [36247.367941] R13: 0000000000000088 R14: 0000000000000087 R15: 0000000000000100
> > [36247.367954] INFO: task kworker/1:2:32265 blocked for more than 120 seconds.
> > [36247.367973]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36247.367989] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36247.368008] kworker/1:2     D    0 32265      2 0x80000000
> > [36247.368020] Workqueue: cifsiod smb2_reconnect_server [cifs]
> > [36247.368021] Call Trace:
> > [36247.368023]  ? __schedule+0x338/0x850
> > [36247.368025]  schedule+0x3c/0x90
> > [36247.368026]  schedule_preempt_disabled+0x14/0x20
> > [36247.368028]  __mutex_lock.isra.7+0x19f/0x540
> > [36247.368037]  ? SMB2_sess_auth_rawntlmssp_authenticate+0x69/0x170 [cifs]
> > [36247.368046]  ? SMB2_sess_setup+0x17f/0x2c0 [cifs]
> > [36247.368054]  ? cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > [36247.368055]  ? _raw_spin_unlock+0x16/0x30
> > [36247.368062]  cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > [36247.368071]  smb2_reconnect+0x2d6/0x4b0 [cifs]
> > [36247.368073]  ? _raw_spin_unlock+0x16/0x30
> > [36247.368074]  ? preempt_count_add+0x67/0xb0
> > [36247.368083]  smb2_reconnect_server+0x1bb/0x350 [cifs]
> > [36247.368090]  process_one_work+0x188/0x3a0
> > [36247.368092]  worker_thread+0x4c/0x3a0
> > [36247.368094]  ? preempt_count_add+0x67/0xb0
> > [36247.368095]  ? process_one_work+0x3a0/0x3a0
> > [36247.368097]  kthread+0xf8/0x130
> > [36247.368099]  ? kthread_create_worker_on_cpu+0x70/0x70
> > [36247.368101]  ret_from_fork+0x35/0x40
> > [36247.368103] INFO: task puppet:3836 blocked for more than 120 seconds.
> > [36247.368119]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36247.368135] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36247.368158] puppet          D    0  3836    541 0x00000000
> > [36247.368159] Call Trace:
> > [36247.368161]  ? __schedule+0x338/0x850
> > [36247.368163]  schedule+0x3c/0x90
> > [36247.368164]  schedule_preempt_disabled+0x14/0x20
> > [36247.368165]  __mutex_lock.isra.7+0x19f/0x540
> > [36247.368166]  ? __switch_to_asm+0x34/0x70
> > [36247.368167]  ? __switch_to_asm+0x40/0x70
> > [36247.368169]  ? try_module_get+0x68/0x100
> > [36247.368178]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36247.368186]  smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36247.368188]  ? _raw_spin_unlock_irq+0x1d/0x30
> > [36247.368189]  ? finish_task_switch+0x7d/0x290
> > [36247.368190]  ? __switch_to_asm+0x40/0x70
> > [36247.368198]  smb2_plain_req_init+0x30/0x240 [cifs]
> > [36247.368199]  ? _raw_spin_lock_irqsave+0x25/0x50
> > [36247.368208]  SMB2_open_init+0x6d/0x7c0 [cifs]
> > [36247.368209]  ? _raw_spin_lock+0x13/0x30
> > [36247.368218]  ? cifs_mid_q_entry_release+0x15/0x40 [cifs]
> > [36247.368227]  ? SMB2_open+0x150/0x520 [cifs]
> > [36247.368235]  SMB2_open+0x150/0x520 [cifs]
> > [36247.368238]  ? sched_clock+0x5/0x10
> > [36247.368247]  ? open_shroot+0x12f/0x200 [cifs]
> > [36247.368255]  open_shroot+0x12f/0x200 [cifs]
> > [36247.368258]  ? __follow_mount_rcu.isra.31+0x3c/0xf0
> > [36247.368267]  smb2_query_path_info+0x93/0x220 [cifs]
> > [36247.368269]  ? walk_component+0x48/0x360
> > [36247.368278]  cifs_get_inode_info+0x580/0xb10 [cifs]
> > [36247.368286]  ? filename_lookup+0xf8/0x1a0
> > [36247.368294]  ? build_path_from_dentry_optional_prefix+0x1e9/0x440 [cifs]
> > [36247.368303]  cifs_revalidate_dentry_attr+0xdc/0x3e0 [cifs]
> > [36247.368311]  cifs_getattr+0x5b/0x1b0 [cifs]
> > [36247.368313]  vfs_statx+0x89/0xe0
> > [36247.368315]  __do_sys_newlstat+0x39/0x70
> > [36247.368318]  do_syscall_64+0x55/0x100
> > [36247.368320]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > [36247.368321] RIP: 0033:0x7f562d3a0335
> > [36247.368323] Code: Bad RIP value.
> > [36247.368324] RSP: 002b:00007ffc6bbc4398 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
> > [36247.368325] RAX: ffffffffffffffda RBX: 00007ffc6bbc43b0 RCX: 00007f562d3a0335
> > [36247.368326] RDX: 00007ffc6bbc43b0 RSI: 00007ffc6bbc43b0 RDI: 000055e4e5e1bd50
> > [36247.368326] RBP: 000055e4e2eb65e0 R08: 0000000000000002 R09: 000055e4e2eb69e0
> > [36247.368327] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
> > [36247.368328] R13: 000055e4e2ef7258 R14: 000055e4e2ef8810 R15: 000055e4e2f92ad0
> > [36368.186922] INFO: task node_exporter:3567 blocked for more than 120 seconds.
> > [36368.186988]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36368.187039] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36368.187097] node_exporter   D    0  3567      1 0x00000000
> > [36368.187102] Call Trace:
> > [36368.187117]  ? __schedule+0x338/0x850
> > [36368.187123]  ? preempt_count_add+0x67/0xb0
> > [36368.187128]  schedule+0x3c/0x90
> > [36368.187133]  schedule_preempt_disabled+0x14/0x20
> > [36368.187138]  __mutex_lock.isra.7+0x19f/0x540
> > [36368.187175]  ? try_module_get+0x68/0x100
> > [36368.187232]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36368.187265]  smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36368.187300]  smb2_plain_req_init+0x30/0x240 [cifs]
> > [36368.187304]  ? __switch_to_asm+0x34/0x70
> > [36368.187307]  ? __switch_to_asm+0x40/0x70
> > [36368.187337]  SMB2_open_init+0x6d/0x7c0 [cifs]
> > [36368.187372]  ? smb2_queryfs+0x13d/0x350 [cifs]
> > [36368.187375]  ? lookup_fast+0xc8/0x2e0
> > [36368.187405]  smb2_queryfs+0x13d/0x350 [cifs]
> > [36368.187410]  ? lookup_fast+0xc8/0x2e0
> > [36368.187416]  ? ___cache_free+0x31/0x2e0
> > [36368.187421]  ? terminate_walk+0x93/0x100
> > [36368.187449]  ? cifs_statfs+0xad/0x300 [cifs]
> > [36368.187471]  cifs_statfs+0xad/0x300 [cifs]
> > [36368.187477]  statfs_by_dentry+0x6a/0x90
> > [36368.187482]  vfs_statfs+0x16/0xc0
> > [36368.187486]  user_statfs+0x50/0xa0
> > [36368.187491]  __do_sys_statfs+0x20/0x50
> > [36368.187499]  do_syscall_64+0x55/0x100
> > [36368.187503]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > [36368.187507] RIP: 0033:0x4a5c20
> > [36368.187517] Code: Bad RIP value.
> > [36368.187519] RSP: 002b:000000c0003ef490 EFLAGS: 00000206 ORIG_RAX: 0000000000000089
> > [36368.187523] RAX: ffffffffffffffda RBX: 000000c00002a000 RCX: 00000000004a5c20
> > [36368.187526] RDX: 0000000000000000 RSI: 000000c0003ef5c0 RDI: 000000c0004510e0
> > [36368.187528] RBP: 000000c0003ef4f0 R08: 0000000000000000 R09: 0000000000000000
> > [36368.187530] R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
> > [36368.187532] R13: 0000000000000088 R14: 0000000000000087 R15: 0000000000000100
> > [36368.187572] INFO: task kworker/1:2:32265 blocked for more than 120 seconds.
> > [36368.187627]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36368.187677] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36368.187735] kworker/1:2     D    0 32265      2 0x80000000
> > [36368.187771] Workqueue: cifsiod smb2_reconnect_server [cifs]
> > [36368.187773] Call Trace:
> > [36368.187780]  ? __schedule+0x338/0x850
> > [36368.187785]  schedule+0x3c/0x90
> > [36368.187790]  schedule_preempt_disabled+0x14/0x20
> > [36368.187795]  __mutex_lock.isra.7+0x19f/0x540
> > [36368.187826]  ? SMB2_sess_auth_rawntlmssp_authenticate+0x69/0x170 [cifs]
> > [36368.187855]  ? SMB2_sess_setup+0x17f/0x2c0 [cifs]
> > [36368.187880]  ? cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > [36368.187885]  ? _raw_spin_unlock+0x16/0x30
> > [36368.187908]  cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > [36368.187936]  smb2_reconnect+0x2d6/0x4b0 [cifs]
> > [36368.187942]  ? _raw_spin_unlock+0x16/0x30
> > [36368.187947]  ? preempt_count_add+0x67/0xb0
> > [36368.187976]  smb2_reconnect_server+0x1bb/0x350 [cifs]
> > [36368.187984]  process_one_work+0x188/0x3a0
> > [36368.187990]  worker_thread+0x4c/0x3a0
> > [36368.187994]  ? preempt_count_add+0x67/0xb0
> > [36368.187998]  ? process_one_work+0x3a0/0x3a0
> > [36368.188001]  kthread+0xf8/0x130
> > [36368.188005]  ? kthread_create_worker_on_cpu+0x70/0x70
> > [36368.188009]  ret_from_fork+0x35/0x40
> > [36368.188014] INFO: task puppet:3836 blocked for more than 120 seconds.
> > [36368.188064]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36368.188114] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36368.188182] puppet          D    0  3836    541 0x00000000
> > [36368.188186] Call Trace:
> > [36368.188191]  ? __schedule+0x338/0x850
> > [36368.188196]  schedule+0x3c/0x90
> > [36368.188200]  schedule_preempt_disabled+0x14/0x20
> > [36368.188205]  __mutex_lock.isra.7+0x19f/0x540
> > [36368.188208]  ? __switch_to_asm+0x34/0x70
> > [36368.188211]  ? __switch_to_asm+0x40/0x70
> > [36368.188215]  ? try_module_get+0x68/0x100
> > [36368.188244]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36368.188271]  smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36368.188277]  ? _raw_spin_unlock_irq+0x1d/0x30
> > [36368.188280]  ? finish_task_switch+0x7d/0x290
> > [36368.188283]  ? __switch_to_asm+0x40/0x70
> > [36368.188310]  smb2_plain_req_init+0x30/0x240 [cifs]
> > [36368.188314]  ? _raw_spin_lock_irqsave+0x25/0x50
> > [36368.188342]  SMB2_open_init+0x6d/0x7c0 [cifs]
> > [36368.188346]  ? _raw_spin_lock+0x13/0x30
> > [36368.188376]  ? cifs_mid_q_entry_release+0x15/0x40 [cifs]
> > [36368.188405]  ? SMB2_open+0x150/0x520 [cifs]
> > [36368.188432]  SMB2_open+0x150/0x520 [cifs]
> > [36368.188440]  ? sched_clock+0x5/0x10
> > [36368.188470]  ? open_shroot+0x12f/0x200 [cifs]
> > [36368.188497]  open_shroot+0x12f/0x200 [cifs]
> > [36368.188503]  ? __follow_mount_rcu.isra.31+0x3c/0xf0
> > [36368.188534]  smb2_query_path_info+0x93/0x220 [cifs]
> > [36368.188539]  ? walk_component+0x48/0x360
> > [36368.188569]  cifs_get_inode_info+0x580/0xb10 [cifs]
> > [36368.188574]  ? filename_lookup+0xf8/0x1a0
> > [36368.188601]  ? build_path_from_dentry_optional_prefix+0x1e9/0x440 [cifs]
> > [36368.188630]  cifs_revalidate_dentry_attr+0xdc/0x3e0 [cifs]
> > [36368.188659]  cifs_getattr+0x5b/0x1b0 [cifs]
> > [36368.188664]  vfs_statx+0x89/0xe0
> > [36368.188670]  __do_sys_newlstat+0x39/0x70
> > [36368.188677]  do_syscall_64+0x55/0x100
> > [36368.188681]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > [36368.188684] RIP: 0033:0x7f562d3a0335
> > [36368.188689] Code: Bad RIP value.
> > [36368.188691] RSP: 002b:00007ffc6bbc4398 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
> > [36368.188695] RAX: ffffffffffffffda RBX: 00007ffc6bbc43b0 RCX: 00007f562d3a0335
> > [36368.188696] RDX: 00007ffc6bbc43b0 RSI: 00007ffc6bbc43b0 RDI: 000055e4e5e1bd50
> > [36368.188698] RBP: 000055e4e2eb65e0 R08: 0000000000000002 R09: 000055e4e2eb69e0
> > [36368.188700] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
> > [36368.188702] R13: 000055e4e2ef7258 R14: 000055e4e2ef8810 R15: 000055e4e2f92ad0
> > [36489.006262] INFO: task node_exporter:3567 blocked for more than 120 seconds.
> > [36489.006300]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36489.006329] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36489.006458] node_exporter   D    0  3567      1 0x00000000
> > [36489.006461] Call Trace:
> > [36489.006470]  ? __schedule+0x338/0x850
> > [36489.006474]  ? preempt_count_add+0x67/0xb0
> > [36489.006476]  schedule+0x3c/0x90
> > [36489.006478]  schedule_preempt_disabled+0x14/0x20
> > [36489.006480]  __mutex_lock.isra.7+0x19f/0x540
> > [36489.006485]  ? try_module_get+0x68/0x100
> > [36489.006515]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36489.006531]  smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36489.006547]  smb2_plain_req_init+0x30/0x240 [cifs]
> > [36489.006549]  ? __switch_to_asm+0x34/0x70
> > [36489.006550]  ? __switch_to_asm+0x40/0x70
> > [36489.006565]  SMB2_open_init+0x6d/0x7c0 [cifs]
> > [36489.006581]  ? smb2_queryfs+0x13d/0x350 [cifs]
> > [36489.006583]  ? lookup_fast+0xc8/0x2e0
> > [36489.006597]  smb2_queryfs+0x13d/0x350 [cifs]
> > [36489.006599]  ? lookup_fast+0xc8/0x2e0
> > [36489.006602]  ? ___cache_free+0x31/0x2e0
> > [36489.006604]  ? terminate_walk+0x93/0x100
> > [36489.006619]  ? cifs_statfs+0xad/0x300 [cifs]
> > [36489.006632]  cifs_statfs+0xad/0x300 [cifs]
> > [36489.006635]  statfs_by_dentry+0x6a/0x90
> > [36489.006637]  vfs_statfs+0x16/0xc0
> > [36489.006639]  user_statfs+0x50/0xa0
> > [36489.006641]  __do_sys_statfs+0x20/0x50
> > [36489.006645]  do_syscall_64+0x55/0x100
> > [36489.006647]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > [36489.006649] RIP: 0033:0x4a5c20
> > [36489.006654] Code: Bad RIP value.
> > [36489.006655] RSP: 002b:000000c0003ef490 EFLAGS: 00000206 ORIG_RAX: 0000000000000089
> > [36489.006657] RAX: ffffffffffffffda RBX: 000000c00002a000 RCX: 00000000004a5c20
> > [36489.006658] RDX: 0000000000000000 RSI: 000000c0003ef5c0 RDI: 000000c0004510e0
> > [36489.006659] RBP: 000000c0003ef4f0 R08: 0000000000000000 R09: 0000000000000000
> > [36489.006660] R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
> > [36489.006661] R13: 0000000000000088 R14: 0000000000000087 R15: 0000000000000100
> > [36489.006675] INFO: task kworker/1:2:32265 blocked for more than 120 seconds.
> > [36489.006812]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36489.006940] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36489.007076] kworker/1:2     D    0 32265      2 0x80000000
> > [36489.007100] Workqueue: cifsiod smb2_reconnect_server [cifs]
> > [36489.007101] Call Trace:
> > [36489.007105]  ? __schedule+0x338/0x850
> > [36489.007107]  schedule+0x3c/0x90
> > [36489.007109]  schedule_preempt_disabled+0x14/0x20
> > [36489.007111]  __mutex_lock.isra.7+0x19f/0x540
> > [36489.007124]  ? SMB2_sess_auth_rawntlmssp_authenticate+0x69/0x170 [cifs]
> > [36489.007134]  ? SMB2_sess_setup+0x17f/0x2c0 [cifs]
> > [36489.007141]  ? cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > [36489.007143]  ? _raw_spin_unlock+0x16/0x30
> > [36489.007150]  cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > [36489.007159]  smb2_reconnect+0x2d6/0x4b0 [cifs]
> > [36489.007161]  ? _raw_spin_unlock+0x16/0x30
> > [36489.007163]  ? preempt_count_add+0x67/0xb0
> > [36489.007172]  smb2_reconnect_server+0x1bb/0x350 [cifs]
> > [36489.007176]  process_one_work+0x188/0x3a0
> > [36489.007178]  worker_thread+0x4c/0x3a0
> > [36489.007179]  ? preempt_count_add+0x67/0xb0
> > [36489.007180]  ? process_one_work+0x3a0/0x3a0
> > [36489.007181]  kthread+0xf8/0x130
> > [36489.007183]  ? kthread_create_worker_on_cpu+0x70/0x70
> > [36489.007184]  ret_from_fork+0x35/0x40
> > [36489.007186] INFO: task puppet:3836 blocked for more than 120 seconds.
> > [36489.007294]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36489.007409] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36489.007540] puppet          D    0  3836    541 0x00000000
> > [36489.007541] Call Trace:
> > [36489.007545]  ? __schedule+0x338/0x850
> > [36489.007548]  schedule+0x3c/0x90
> > [36489.007550]  schedule_preempt_disabled+0x14/0x20
> > [36489.007552]  __mutex_lock.isra.7+0x19f/0x540
> > [36489.007553]  ? __switch_to_asm+0x34/0x70
> > [36489.007555]  ? __switch_to_asm+0x40/0x70
> > [36489.007558]  ? try_module_get+0x68/0x100
> > [36489.007580]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36489.007594]  smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36489.007596]  ? _raw_spin_unlock_irq+0x1d/0x30
> > [36489.007598]  ? finish_task_switch+0x7d/0x290
> > [36489.007600]  ? __switch_to_asm+0x40/0x70
> > [36489.007613]  smb2_plain_req_init+0x30/0x240 [cifs]
> > [36489.007615]  ? _raw_spin_lock_irqsave+0x25/0x50
> > [36489.007628]  SMB2_open_init+0x6d/0x7c0 [cifs]
> > [36489.007630]  ? _raw_spin_lock+0x13/0x30
> > [36489.007644]  ? cifs_mid_q_entry_release+0x15/0x40 [cifs]
> > [36489.007658]  ? SMB2_open+0x150/0x520 [cifs]
> > [36489.007672]  SMB2_open+0x150/0x520 [cifs]
> > [36489.007677]  ? sched_clock+0x5/0x10
> > [36489.007692]  ? open_shroot+0x12f/0x200 [cifs]
> > [36489.007707]  open_shroot+0x12f/0x200 [cifs]
> > [36489.007711]  ? __follow_mount_rcu.isra.31+0x3c/0xf0
> > [36489.007727]  smb2_query_path_info+0x93/0x220 [cifs]
> > [36489.007729]  ? walk_component+0x48/0x360
> > [36489.007745]  cifs_get_inode_info+0x580/0xb10 [cifs]
> > [36489.007748]  ? filename_lookup+0xf8/0x1a0
> > [36489.007762]  ? build_path_from_dentry_optional_prefix+0x1e9/0x440 [cifs]
> > [36489.007778]  cifs_revalidate_dentry_attr+0xdc/0x3e0 [cifs]
> > [36489.007791]  cifs_getattr+0x5b/0x1b0 [cifs]
> > [36489.007794]  vfs_statx+0x89/0xe0
> > [36489.007797]  __do_sys_newlstat+0x39/0x70
> > [36489.007801]  do_syscall_64+0x55/0x100
> > [36489.007802]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > [36489.007805] RIP: 0033:0x7f562d3a0335
> > [36489.007808] Code: Bad RIP value.
> > [36489.007809] RSP: 002b:00007ffc6bbc4398 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
> > [36489.007811] RAX: ffffffffffffffda RBX: 00007ffc6bbc43b0 RCX: 00007f562d3a0335
> > [36489.007812] RDX: 00007ffc6bbc43b0 RSI: 00007ffc6bbc43b0 RDI: 000055e4e5e1bd50
> > [36489.007813] RBP: 000055e4e2eb65e0 R08: 0000000000000002 R09: 000055e4e2eb69e0
> > [36489.007814] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
> > [36489.007815] R13: 000055e4e2ef7258 R14: 000055e4e2ef8810 R15: 000055e4e2f92ad0
> > [36609.825705] INFO: task node_exporter:3567 blocked for more than 120 seconds.
> > [36609.825836]       Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > [36609.825869] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [36609.825908] node_exporter   D    0  3567      1 0x00000000
> > [36609.825910] Call Trace:
> > [36609.825919]  ? __schedule+0x338/0x850
> > [36609.825922]  ? preempt_count_add+0x67/0xb0
> > [36609.825925]  schedule+0x3c/0x90
> > [36609.825927]  schedule_preempt_disabled+0x14/0x20
> > [36609.825929]  __mutex_lock.isra.7+0x19f/0x540
> > [36609.825933]  ? try_module_get+0x68/0x100
> > [36609.825960]  ? smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36609.825979]  smb2_reconnect+0x1d7/0x4b0 [cifs]
> > [36609.825999]  smb2_plain_req_init+0x30/0x240 [cifs]
> > [36609.826001]  ? __switch_to_asm+0x34/0x70
> > [36609.826002]  ? __switch_to_asm+0x40/0x70
> > [36609.826020]  SMB2_open_init+0x6d/0x7c0 [cifs]
> > [36609.826039]  ? smb2_queryfs+0x13d/0x350 [cifs]
> > [36609.826040]  ? lookup_fast+0xc8/0x2e0
> > [36609.826057]  smb2_queryfs+0x13d/0x350 [cifs]
> > [36609.826060]  ? lookup_fast+0xc8/0x2e0
> > [36609.826064]  ? ___cache_free+0x31/0x2e0
> > [36609.826066]  ? terminate_walk+0x93/0x100
> > [36609.826084]  ? cifs_statfs+0xad/0x300 [cifs]
> > [36609.826099]  cifs_statfs+0xad/0x300 [cifs]
> > [36609.826103]  statfs_by_dentry+0x6a/0x90
> > [36609.826104]  vfs_statfs+0x16/0xc0
> > [36609.826106]  user_statfs+0x50/0xa0
> > [36609.826108]  __do_sys_statfs+0x20/0x50
> > [36609.826113]  do_syscall_64+0x55/0x100
> > [36609.826115]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > [36609.826117] RIP: 0033:0x4a5c20
> > [36609.826123] Code: Bad RIP value.
> > [36609.826124] RSP: 002b:000000c0003ef490 EFLAGS: 00000206 ORIG_RAX: 0000000000000089
> > [36609.826126] RAX: ffffffffffffffda RBX: 000000c00002a000 RCX: 00000000004a5c20
> > [36609.826127] RDX: 0000000000000000 RSI: 000000c0003ef5c0 RDI: 000000c0004510e0
> > [36609.826128] RBP: 000000c0003ef4f0 R08: 0000000000000000 R09: 0000000000000000
> > [36609.826129] R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
> > [36609.826130] R13: 0000000000000088 R14: 0000000000000087 R15: 0000000000000100
> > [73117.654990] CIFS VFS: Send error in SessSetup = -126
> >
> > Regards, Martijn
> >
> > >
> > > --
> > > Best regards,
> > > Pavel Shilovsky
> > >
> > > чт, 4 июл. 2019 г. в 06:36, Martijn de Gouw
> > > <martijn.de.gouw@prodrive-technologies.com>:
> > >>
> > >> Hi,
> > >>
> > >> On 04-07-2019 13:22, Aurélien Aptel wrote:
> > >>> Martijn de Gouw <martijn.de.gouw@prodrive-technologies.com> writes:
> > >>>>> Are there any kernel oops/panic with stack traces and register dumps in
> > >>>>> the log?
> > >>>>>
> > >>>>> You can inspect the kernel stack trace of the hung processes (to see where
> > >>>>> they are stuck) by printing the file /proc/<pid>/stack.
> > >>>>
> > >>>> These are the stacks of all processes that are D, most of them being df.
> > >>>> I also attached the cifs Stats output below.
> > >>>
> > >>> Ok thanks. What about Oops or BUG or panic in dmesg logs, did you see
> > >>> any?
> > >>
> > >> I did find the following messages in the dmesg of one of the servers:
> > >>
> > >> [    4.797893] FS-Cache: Duplicate cookie detected
> > >> [    4.797915] FS-Cache: O-cookie c=000000001a791554 [p=00000000fb6f31ee fl=222 nc=0 na=1]
> > >> [    4.797934] FS-Cache: O-cookie d=0000000020a06fab n=00000000654600e7
> > >> [    4.797949] FS-Cache: O-key=[8] '020001bd0a010102'
> > >> [    4.797963] FS-Cache: N-cookie c=000000005d0bf4a5 [p=00000000fb6f31ee fl=2 nc=0 na=1]
> > >> [    4.797982] FS-Cache: N-cookie d=0000000020a06fab n=000000004e1e47aa
> > >> [    4.797997] FS-Cache: N-key=[8] '020001bd0a010102'
> > >> [    4.798643] FS-Cache: Duplicate cookie detected
> > >> [    4.798659] FS-Cache: O-cookie c=000000001a791554 [p=00000000fb6f31ee fl=222 nc=0 na=1]
> > >> [    4.798679] FS-Cache: O-cookie d=0000000020a06fab n=00000000654600e7
> > >> [    4.798695] FS-Cache: O-key=[8] '020001bd0a010102'
> > >> [    4.798714] FS-Cache: N-cookie c=00000000cbe44971 [p=00000000fb6f31ee fl=2 nc=0 na=1]
> > >> [    4.798733] FS-Cache: N-cookie d=0000000020a06fab n=00000000ab0e78a6
> > >> [    4.798747] FS-Cache: N-key=[8] '020001bd0a010102'
> > >> [    4.906667] FS-Cache: Netfs 'nfs' registered for caching
> > >> [12738.729173] CIFS VFS: Send error in SessSetup = -126
> > >> [99125.480751] CIFS VFS: Send error in SessSetup = -126
> > >> [185517.295175] CIFS VFS: Send error in SessSetup = -126
> > >> [250515.749714] kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
> > >> [250515.749740] BUG: unable to handle kernel paging request at ffff8ec52a6fe1d0
> > >> [250515.749757] PGD 1b2602067 P4D 1b2602067 PUD 42dbff063 PMD 42a357063 PTE 800000042a6fe063
> > >> [250515.749779] Oops: 0011 [#1] PREEMPT SMP PTI
> > >> [250515.749792] CPU: 1 PID: 796 Comm: cifsd Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > >> [250515.749812] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/19/2018
> > >> [250515.749844] RIP: 0010:0xffff8ec52a6fe1d0
> > >> [250515.749860] Code: ff ff 00 00 00 00 fd 01 00 00 00 7d 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <d0> e1 6f 2a c5 8e ff ff d0 e1 6f 2a c5 8e ff ff 80 70 82 2b c5 8e
> > >> [250515.749914] RSP: 0018:ffff9e60c2e2bdc0 EFLAGS: 00010202
> > >> [250515.749927] RAX: ffff8ec52a6fe1d0 RBX: ffff8ec526fce800 RCX: dead000000000200
> > >> [250515.749944] RDX: ffff8ec52d3e6800 RSI: 0000000000000246 RDI: ffff8ec52a6fe198
> > >> [250515.749962] RBP: ffff8ec52d3e6800 R08: 0000000000000002 R09: ffff8ec52a6fe170
> > >> [250515.749979] R10: ffff9e60c2e2bc10 R11: ffff8ec527088000 R12: ffff8ec526fce9c0
> > >> [250515.749997] R13: ffff8ec52d3e6800 R14: ffff9e60c2e2bdd8 R15: ffff8ec52d3e6b80
> > >> [250515.750014] FS:  0000000000000000(0000) GS:ffff8ec52fa80000(0000) knlGS:0000000000000000
> > >> [250515.750033] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > >> [250515.750048] CR2: ffff8ec52a6fe1d0 CR3: 000000042a53c005 CR4: 00000000003606e0
> > >> [250515.750100] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > >> [250515.750102] CIFS VFS: No task to wake, unknown frame received! NumMids 3
> > >> [250515.750119] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > >> [250515.750120] Call Trace:
> > >> [250515.750149] 00000000: 424d53fe 00010040 00000000 00000005  .SMB@...........
> > >> [250515.750193]  ? cifs_reconnect+0x337/0x880 [cifs]
> > >> [250515.750201]  ? cifs_handle_standard+0x169/0x190 [cifs]
> > >> [250515.750216] 00000010: 10000009 00000098 00000db2 00000000  ................
> > >> [250515.750234]  ? cifs_demultiplex_thread+0x9e5/0xbc0 [cifs]
> > >> [250515.750240] 00000020: 0000025c 00000001 640002e9 0000c81d  \..........d....
> > >> [250515.750259]  ? finish_task_switch+0x7d/0x290
> > >> [250515.750271] 00000030: 5a9e63f3 6204a9b0 587058e3 0d45419b  .c.Z...b.XpX.AE.
> > >> [250515.750295]  ? cifs_handle_standard+0x190/0x190 [cifs]
> > >> [250515.750728] CIFS VFS: No task to wake, unknown frame received! NumMids 3
> > >> [250515.751200]  ? kthread+0xf8/0x130
> > >> [250515.751639] 00000000: 424d53fe 00010040 00000000 00000010  .SMB@...........
> > >> [250515.752102]  ? kthread_create_worker_on_cpu+0x70/0x70
> > >> [250515.752554] 00000010: 0000000d 00000068 00000db3 00000000  ....h...........
> > >> [250515.752997]  ? ret_from_fork+0x35/0x40
> > >> [250515.753429] 00000020: 0000025c 00000001 640002e9 0000c81d  \..........d....
> > >> [250515.753874] Modules linked in: cpufreq_userspace(E) cpufreq_powersave(E) cpufreq_conservative(E) arc4(E) ecb(E) md4(E) nfsv3(E) nfs_acl(E) nfs(E) sha512_ssse3(E) sha512_generic(E) lockd(E) cmac(E) grace(E) hmac(E) nls_utf8(E) cifs(E) ccm(E) dns_resolver(E) fscache(E) vmw_vsock_vmci_transport(E) vsock(E) sb_edac(E) crct10dif_pclmul(E) crc32_pclmul(E) ghash_clmulni_intel(E) aesni_intel(E) vmw_balloon(E) aes_x86_64(E) joydev(E) evdev(E) crypto_simd(E) vmwgfx(E) serio_raw(E) cryptd(E) glue_helper(E) ttm(E) sg(E) vmw_vmci(E) drm_kms_helper(E) drm(E) button(E) ac(E) auth_rpcgss(E) sunrpc(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc32c_generic(E) crc16(E) mbcache(E) jbd2(E) sr_mod(E) cdrom(E) ata_generic(E) sd_mod(E) ata_piix(E) crc32c_intel(E) psmouse(E) libata(E) vmw_pvscsi(E) vmxnet3(E) scsi_mod(E) i2c_piix4(E)
> > >> [250515.754336] 00000030: 49d4fd21 858665a2 fde5288f 01d2d919  !..I.e...(......
> > >> [250515.754766] CR2: ffff8ec52a6fe1d0
> > >> [250515.758927] CIFS VFS: No task to wake, unknown frame received! NumMids 3
> > >> [250515.759389] ---[ end trace 92ea62cd080150de ]---
> > >> [250515.759879] 00000000: 424d53fe 00010040 00000000 00030006  .SMB@...........
> > >> [250515.760357] RIP: 0010:0xffff8ec52a6fe1d0
> > >> [250515.761841] Code: ff ff 00 00 00 00 fd 01 00 00 00 7d 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <d0> e1 6f 2a c5 8e ff ff d0 e1 6f 2a c5 8e ff ff 80 70 82 2b c5 8e
> > >> [250515.763287] RSP: 0018:ffff9e60c2e2bdc0 EFLAGS: 00010202
> > >> [250515.763778] RAX: ffff8ec52a6fe1d0 RBX: ffff8ec526fce800 RCX: dead000000000200
> > >> [250515.764060] 00000010: 0000000d 00000000 00000db4 00000000  ................
> > >> [250515.764310] RDX: ffff8ec52d3e6800 RSI: 0000000000000246 RDI: ffff8ec52a6fe198
> > >> [250515.764311] RBP: ffff8ec52d3e6800 R08: 0000000000000002 R09: ffff8ec52a6fe170
> > >> [250515.764312] R10: ffff9e60c2e2bc10 R11: ffff8ec527088000 R12: ffff8ec526fce9c0
> > >> [250515.764314] R13: ffff8ec52d3e6800 R14: ffff9e60c2e2bdd8 R15: ffff8ec52d3e6b80
> > >> [250515.765491] 00000020: 0000025c 00000001 640002e9 0000c81d  \..........d....
> > >> [250515.765836] FS:  0000000000000000(0000) GS:ffff8ec52fa80000(0000) knlGS:0000000000000000
> > >> [250515.767899] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > >> [250515.768367] CR2: ffff8ec52a6fe1d0 CR3: 000000042a53c005 CR4: 00000000003606e0
> > >> [250515.768919] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > >> [250515.769419] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > >> [250515.769591] 00000030: 879543e1 572c0574 e53861ba 97ccc40b  .C..t.,W.a8.....
> > >> [271909.743603] CIFS VFS: Send error in SessSetup = -126
> > >> [358301.908585] CIFS VFS: Send error in SessSetup = -126
> > >> [444693.566453] CIFS VFS: Send error in SessSetup = -126
> > >> [531086.090040] CIFS VFS: Send error in SessSetup = -126
> > >> [617477.785390] CIFS VFS: Send error in SessSetup = -126
> > >> [703869.556705] CIFS VFS: Send error in SessSetup = -126
> > >> [790261.656853] CIFS VFS: Send error in SessSetup = -126
> > >> [876653.496928] CIFS VFS: Send error in SessSetup = -126
> > >> [963045.816742] CIFS VFS: Send error in SessSetup = -126
> > >> [1049437.566219] CIFS VFS: Send error in SessSetup = -126
> > >>
> > >>
> > >> And from another server:
> > >> [    4.253091] FS-Cache: Duplicate cookie detected
> > >> [    4.253120] FS-Cache: O-cookie c=000000004cc29d26 [p=0000000017dbbbc0 fl=222 nc=0 na=1]
> > >> [    4.253153] FS-Cache: O-cookie d=00000000e8e68765 n=0000000012869fa7
> > >> [    4.253179] FS-Cache: O-key=[8] '020001bd0a010102'
> > >> [    4.253201] FS-Cache: N-cookie c=00000000c3bbbddd [p=0000000017dbbbc0 fl=2 nc=0 na=1]
> > >> [    4.253235] FS-Cache: N-cookie d=00000000e8e68765 n=00000000335882b3
> > >> [    4.253262] FS-Cache: N-key=[8] '020001bd0a010102'
> > >> [    4.254107] FS-Cache: Duplicate cookie detected
> > >> [    4.254130] FS-Cache: O-cookie c=000000004cc29d26 [p=0000000017dbbbc0 fl=222 nc=0 na=1]
> > >> [    4.254161] FS-Cache: O-cookie d=00000000e8e68765 n=0000000012869fa7
> > >> [    4.254185] FS-Cache: O-key=[8] '020001bd0a010102'
> > >> [    4.254230] FS-Cache: N-cookie c=000000000ec2f0bb [p=0000000017dbbbc0 fl=2 nc=0 na=1]
> > >> [    4.254261] FS-Cache: N-cookie d=00000000e8e68765 n=0000000024706210
> > >> [    4.254285] FS-Cache: N-key=[8] '020001bd0a010102'
> > >> [    4.329147] CIFS VFS: BAD_NETWORK_NAME: \\stor02.bk.prodrive.nl\userdata$
> > >> [    4.330107] CIFS VFS: cifs_mount failed w/return code = -2
> > >> [65206.127542] CIFS VFS: Send error in SessSetup = -126
> > >> [151597.808064] CIFS VFS: Send error in SessSetup = -126
> > >> [237989.956447] CIFS VFS: Send error in SessSetup = -126
> > >> [324380.937984] CIFS VFS: Send error in SessSetup = -126
> > >> [402750.869518] kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
> > >> [402750.869594] BUG: unable to handle kernel paging request at ffff909bf61609d0
> > >> [402750.869650] PGD 1ac02067 P4D 1ac02067 PUD 1385f5063 PMD 136142063 PTE 8000000136160063
> > >> [402750.869716] Oops: 0011 [#1] PREEMPT SMP PTI
> > >> [402750.869753] CPU: 0 PID: 797 Comm: cifsd Tainted: G            E     4.20.17-pd-4.20.y #20190611
> > >> [402750.869818] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/19/2018
> > >> [402750.869926] CIFS VFS: No task to wake, unknown frame received! NumMids 3
> > >> [402750.869947] RIP: 0010:0xffff909bf61609d0
> > >> [402750.870013] 00000000: 424d53fe 00010040 00000000 00000005  .SMB@...........
> > >> [402750.870198] Code: ff ff 00 00 00 00 4e 01 00 00 00 7d 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <d0> 09 16 f6 9b 90 ff ff d0 09 16 f6 9b 90 ff ff c0 40 1f f2 9b 90
> > >> [402750.870275] 00000010: 10000009 00000098 000002b5 00000000  ................
> > >> [402750.870450] RSP: 0000:ffffa18d41adbd28 EFLAGS: 00010202
> > >> [402750.870469] 00000020: 000001cd 00000001 44000cd9 0000c824  ...........D$...
> > >> [402750.870509] RAX: ffff909bf61609d0 RBX: ffff909bf6c3f800 RCX: dead000000000200
> > >> [402750.870511] RDX: ffff909bf74fa980 RSI: 0000000000000246 RDI: ffff909bf6160998
> > >> [402750.870530] 00000030: 79955e4a 0dacb8eb 025edebd 4efa7788  J^.y......^..w.N
> > >> [402750.870582] RBP: ffff909bf74fa980 R08: 0000000000000000 R09: ffff909bf6c3f970
> > >> [402750.870585] R10: ffffa18d406a7cc0 R11: 0000000000000000 R12: ffff909bf6c3f9c0
> > >> [402750.870605] CIFS VFS: No task to wake, unknown frame received! NumMids 3
> > >> [402750.870656] R13: ffff909bf74fa980 R14: ffffa18d41adbd40 R15: ffff909bf74fa100
> > >> [402750.870660] FS:  0000000000000000(0000) GS:ffff909bf9c00000(0000) knlGS:0000000000000000
> > >> [402750.870677] 00000000: 424d53fe 00010040 00000000 00000010  .SMB@...........
> > >> [402750.870731] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > >> [402750.870733] CR2: ffff909bf61609d0 CR3: 0000000136e56004 CR4: 00000000003606f0
> > >> [402750.870752] 00000010: 0000000d 00000068 000002b6 00000000  ....h...........
> > >> [402750.870888] 00000020: 000001cd 00000001 44000cd9 0000c824  ...........D$...
> > >> [402750.870894] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > >> [402750.870907] 00000030: f063942a cae9f6e1 d5327c26 91fc6f33  *.c.....&|2.3o..
> > >> [402750.872321] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > >> [402750.872324] Call Trace:
> > >> [402750.872381]  ? cifs_reconnect+0x337/0x880 [cifs]
> > >> [402750.872410]  ? cifs_readv_from_socket+0x211/0x260 [cifs]
> > >> [402750.875687]  ? cifs_read_from_socket+0x4a/0x70 [cifs]
> > >> [402750.876128]  ? _raw_spin_unlock_irqrestore+0x20/0x40
> > >> [402750.876555]  ? try_to_wake_up+0x54/0x540
> > >> [402750.876991]  ? cifs_small_buf_get+0x16/0x20 [cifs]
> > >> [402750.877426]  ? cifs_demultiplex_thread+0xdd/0xbc0 [cifs]
> > >> [402750.877834]  ? finish_task_switch+0x7d/0x290
> > >> [402750.878252]  ? cifs_handle_standard+0x190/0x190 [cifs]
> > >> [402750.878651]  ? kthread+0xf8/0x130
> > >> [402750.879034]  ? kthread_create_worker_on_cpu+0x70/0x70
> > >> [402750.879412]  ? ret_from_fork+0x35/0x40
> > >> [402750.879786] Modules linked in: cpufreq_conservative(E) cpufreq_powersave(E) cpufreq_userspace(E) arc4(E) ecb(E) md4(E) sha512_ssse3(E) sha512_generic(E) cmac(E) hmac(E) nfsv3(E) nfs_acl(E) nls_utf8(E) nfs(E) lockd(E) grace(E) cifs(E) ccm(E) dns_resolver(E) fscache(E) sb_edac(E) crct10dif_pclmul(E) crc32_pclmul(E) ghash_clmulni_intel(E) aesni_intel(E) aes_x86_64(E) crypto_simd(E) joydev(E) cryptd(E) vmw_balloon(E) evdev(E) glue_helper(E) serio_raw(E) vmwgfx(E) ttm(E) drm_kms_helper(E) sg(E) drm(E) vmw_vsock_vmci_transport(E) vsock(E) vmw_vmci(E) ac(E) button(E) auth_rpcgss(E) sunrpc(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc32c_generic(E) crc16(E) mbcache(E) jbd2(E) sr_mod(E) cdrom(E) sd_mod(E) ata_generic(E) ata_piix(E) vmw_pvscsi(E) libata(E) crc32c_intel(E) psmouse(E) vmxnet3(E) i2c_piix4(E) scsi_mod(E)
> > >> [402750.883384] CR2: ffff909bf61609d0
> > >> [402750.883783] ---[ end trace 08b06875e82513eb ]---
> > >> [402750.884200] RIP: 0010:0xffff909bf61609d0
> > >> [402750.884598] Code: ff ff 00 00 00 00 52 01 00 00 00 7d 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <d0> 09 16 f6 9b 90 ff ff d0 09 16 f6 9b 90 ff ff c0 40 1f f2 9b 90
> > >> [402750.885822] RSP: 0000:ffffa18d41adbd28 EFLAGS: 00010202
> > >> [402750.886229] RAX: ffff909bf61609d0 RBX: ffff909bf6c3f800 RCX: dead000000000200
> > >> [402750.886651] RDX: ffff909bf74fa980 RSI: 0000000000000246 RDI: ffff909bf6160998
> > >> [402750.887065] RBP: ffff909bf74fa980 R08: 0000000000000000 R09: ffff909bf6c3f970
> > >> [402750.887478] R10: ffffa18d406a7cc0 R11: 0000000000000000 R12: ffff909bf6c3f9c0
> > >> [402750.887883] R13: ffff909bf74fa980 R14: ffffa18d41adbd40 R15: ffff909bf74fa100
> > >> [402750.888285] FS:  0000000000000000(0000) GS:ffff909bf9c00000(0000) knlGS:0000000000000000
> > >> [402750.888692] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > >> [402750.889093] CR2: ffff909bf61609d0 CR3: 0000000136e56004 CR4: 00000000003606f0
> > >> [402750.889559] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > >> [402750.889972] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > >> [410772.901264] CIFS VFS: Send error in SessSetup = -126
> > >> [497165.194662] CIFS VFS: Send error in SessSetup = -126
> > >> [583557.492304] CIFS VFS: Send error in SessSetup = -126
> > >> [669948.937016] CIFS VFS: Send error in SessSetup = -126
> > >> [756341.390112] CIFS VFS: Send error in SessSetup = -126
> > >> [842733.557002] CIFS VFS: Send error in SessSetup = -126
> > >> [929125.303428] CIFS VFS: Send error in SessSetup = -126
> > >> [1015516.629380] CIFS VFS: Send error in SessSetup = -126
> > >> [1101908.464697] CIFS VFS: Send error in SessSetup = -126
> > >> [1188300.531261] CIFS VFS: Send error in SessSetup = -126
> > >> [1274692.583049] CIFS VFS: Send error in SessSetup = -126
> > >>
> > >>
> > >>>
> > >>> The individual stack dumps are pretty useful. Here is my theory:
> > >>>
> > >>>> pid: 9505
> > >>>> syscall: 4 0x56550a2ec470 0x7ffede42e9a0 0x7ffede42e9a0 0x83a 0x3 0x20
> > >>>> 0x7ffede42e8f8 0x7f7f8928f295
> > >>>> [<0>] open_shroot+0x43/0x200 [cifs]
> > >>>> [<0>] smb2_query_path_info+0x93/0x220 [cifs]
> > >>>
> > >>> Almost all of the processes have the same stack trace. They are stuck at
> > >>> open_shroot()+0x43 which is probably
> > >>>
> > >>>       mutex_lock(&tcon->crfid.fid_mutex);
> > >>>
> > >>> Then there are only 2 other processes stuck somewhere in the same code path
> > >>> (open_shroot) but deeper, meaning they have the locks that the other
> > >>> processes are waiting for:
> > >>>
> > >>>
> > >>>> pid: 22858
> > >>>> syscall: 4 0x564b46285d10 0x7ffcea3f9a80 0x7ffcea3f9a80 0x83a 0x3 0x20
> > >>>> 0x7ffcea3f99d8 0x7f6cc78c7295
> > >>>> [<0>] cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > >>>> [<0>] smb2_reconnect+0x2d6/0x4b0 [cifs]
> > >>>> [<0>] smb2_plain_req_init+0x30/0x240 [cifs]
> > >>>> [<0>] SMB2_open_init+0x6d/0x7c0 [cifs]
> > >>>> [<0>] SMB2_open+0x150/0x520 [cifs]
> > >>>> [<0>] open_shroot+0x12f/0x200 [cifs]
> > >>>> [<0>] smb2_query_path_info+0x93/0x220 [cifs]
> > >>>> [<0>] cifs_get_inode_info+0x580/0xb10 [cifs]
> > >>>> [<0>] cifs_revalidate_dentry_attr+0xdc/0x3e0 [cifs]
> > >>>> [<0>] cifs_getattr+0x5b/0x1b0 [cifs]
> > >>>> [<0>] vfs_statx+0x89/0xe0
> > >>>> [<0>] __do_sys_newstat+0x39/0x70
> > >>>> [<0>] do_syscall_64+0x55/0x100
> > >>>> [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > >>>> [<0>] 0xffffffffffffffff
> > >>>
> > >>>
> > >>>> pid: 20027
> > >>>> syscall: 4 0x55a3c7d767d0 0x7ffe51432ab0 0x7ffe51432ab0 0x83a
> > >>>> 0x55a3c7d75c40 0x20 0x7ffe51432a08 0x7f5f7c4e7295
> > >>>> [<0>] cifs_mark_open_files_invalid+0x54/0xa0 [cifs]
> > >>>> [<0>] smb2_reconnect+0x2d6/0x4b0 [cifs]
> > >>>> [<0>] smb2_plain_req_init+0x30/0x240 [cifs]
> > >>>> [<0>] SMB2_open_init+0x6d/0x7c0 [cifs]
> > >>>> [<0>] SMB2_open+0x150/0x520 [cifs]
> > >>>> [<0>] open_shroot+0x12f/0x200 [cifs]
> > >>>> [<0>] smb2_query_path_info+0x93/0x220 [cifs]
> > >>>> [<0>] cifs_get_inode_info+0x580/0xb10 [cifs]
> > >>>> [<0>] cifs_revalidate_dentry_attr+0xdc/0x3e0 [cifs]
> > >>>> [<0>] cifs_getattr+0x5b/0x1b0 [cifs]
> > >>>> [<0>] vfs_statx+0x89/0xe0
> > >>>> [<0>] __do_sys_newstat+0x39/0x70
> > >>>> [<0>] do_syscall_64+0x55/0x100
> > >>>> [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > >>>> [<0>] 0xffffffffffffffff
> > >>>
> > >>> Due to timeouts maybe the Open request needs
> > >>> to reconnect the server/ses/tcon and to do this it calls
> > >>> cifs_mark_open_files_invalid() and gets stuck somewhere there.
> > >>>
> > >>>           spin_lock(&tcon->open_file_lock);
> > >>>           list_for_each_safe(tmp, tmp1, &tcon->openFileList) {
> > >>>                   open_file = list_entry(tmp, struct cifsFileInfo, tlist);
> > >>>                   open_file->invalidHandle = true;
> > >>>                   open_file->oplock_break_cancelled = true;
> > >>>           }
> > >>>           spin_unlock(&tcon->open_file_lock);
> > >>>
> > >>>           mutex_lock(&tcon->crfid.fid_mutex); <=== most likely here
> > >>>           tcon->crfid.is_valid = false;
> > >>>           memset(tcon->crfid.fid, 0, sizeof(struct cifs_fid));
> > >>>           mutex_unlock(&tcon->crfid.fid_mutex);
> > >>>
> > >>> I think these processes are trying to lock the same lock twice: one in
> > >>> open_shroot() and since Open ends up having to reconnect, once again in
> > >>> mark_open_files_invalid(). I think it's the same lock because I don't
> > >>> see why the tcon pointers would be different in those 2 spots. Kernel
> > >>> mutexes are not reentrant so this is a deadlock.
> > >>
> > >> Is there anything we can do about this? Is this maybe already fixed in newer kernels?
> > >>
> > >> Regards, Martijn
> > >>
> > >>>
> > >>> Cheers,
> > >>>
> > >>
> > >> --
> > >> Martijn de Gouw
> > >> Designer
> > >> Prodrive Technologies
> > >> Mobile: +31 63 17 76 161
> > >> Phone:  +31 40 26 76 200
> >
> > --
> > Martijn de Gouw
> > Designer
> > Prodrive Technologies
> > Mobile: +31 63 17 76 161
> > Phone:  +31 40 26 76 200
>
>
>
> --
> Thanks,
>
> Steve