We have exactly the same issue with latest upstream kernel from ubuntu, i.e. 4.2.0-18-generic.
This issue is really annoying and looks like it doesn't depend on load. Means it can hang with only few processes accessing CIFS share. Looks like it is some kind of race condition with exclusive lock request on CIFS share. Our main proccess uses those and constantly got hanged. Sometimes it is a matter of days, sometimes it hangs within 15 minutes. #bug-exists-upstream -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1428045 Title: CIFS hangs at cifs_oplock_break Status in linux package in Ubuntu: Expired Bug description: we're having constant issues with CIFS mounts on our Linux terminal servers (Ubuntu 12.04 and 14.04 with updated kernel). Usually after 1 or 2 days we see the following in dmesg: [102000.440031] INFO: task cifsiod:2184 blocked for more than 120 seconds. [102000.441342] Not tainted 3.19.0-7-generic #7-Ubuntu [102000.441454] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [102000.441617] cifsiod D ffff8800363dfc98 0 2184 2 0x00000000 [102000.441796] Workqueue: cifsiod cifs_oplock_break [cifs] [102000.442048] ffff8800363dfc98 ffff8800368b09d0 0000000000014200 ffff8800363dffd8 [102000.442215] 0000000000014200 ffff88013ab9bae0 ffff8800368b09d0 0000000000000246 [102000.442382] ffff8800363dfd30 ffff88013ffd7c88 0000000000000002 ffffffff817cb120 [102000.442628] Call Trace: [102000.442681] [<ffffffff817cb120>] ? bit_wait_io+0x50/0x50 [102000.442828] [<ffffffff817ca4c9>] schedule+0x29/0x70 [102000.442926] [<ffffffff817cb14b>] bit_wait+0x2b/0x50 [102000.443023] [<ffffffff817caca7>] __wait_on_bit+0x67/0x90 [102000.443128] [<ffffffff810a2857>] ? wake_up_process+0x27/0x50 [102000.443240] [<ffffffff817cb120>] ? bit_wait_io+0x50/0x50 [102000.443345] [<ffffffff817cad42>] out_of_line_wait_on_bit+0x72/0x80 [102000.443466] [<ffffffff810b6f70>] ? autoremove_wake_function+0x40/0x40 [102000.443736] [<ffffffffc037689b>] cifs_oplock_break+0x6b/0x330 [cifs] [102000.443994] [<ffffffff8108f218>] process_one_work+0x158/0x460 [102000.444250] [<ffffffff8108f6ac>] rescuer_thread+0x18c/0x460 [102000.444495] [<ffffffff8108f520>] ? process_one_work+0x460/0x460 [102000.444745] [<ffffffff810950e9>] kthread+0xc9/0xe0 [102000.444975] [<ffffffff81095020>] ? kthread_create_on_node+0x1c0/0x1c0 [102000.445234] [<ffffffff817cf2bc>] ret_from_fork+0x7c/0xb0 [102000.445472] [<ffffffff81095020>] ? kthread_create_on_node+0x1c0/0x1c0 and later [102000.445739] INFO: task kworker/3:2:20985 blocked for more than 120 seconds. [102000.446004] Not tainted 3.19.0-7-generic #7-Ubuntu [102000.446239] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [102000.446657] kworker/3:2 D ffff8800bae87cb8 0 20985 2 0x00000000 [102000.446949] Workqueue: cifsiod cifs_oplock_break [cifs] [102000.447187] ffff8800bae87cb8 ffff8800baed9d70 0000000000014200 ffff8800bae87fd8 [102000.447613] 0000000000014200 ffff88013abf44b0 ffff8800baed9d70 0000000000000246 [102000.448047] ffff8800bae87d50 ffff88013ffd7c88 0000000000000002 ffffffff817cb120 [102000.448477] Call Trace: [102000.448659] [<ffffffff817cb120>] ? bit_wait_io+0x50/0x50 [102000.448896] [<ffffffff817ca4c9>] schedule+0x29/0x70 [102000.449127] [<ffffffff817cb14b>] bit_wait+0x2b/0x50 [102000.449360] [<ffffffff817caca7>] __wait_on_bit+0x67/0x90 [102000.449595] [<ffffffff817cb120>] ? bit_wait_io+0x50/0x50 [102000.449834] [<ffffffff817cad42>] out_of_line_wait_on_bit+0x72/0x80 [102000.450085] [<ffffffff810b6f70>] ? autoremove_wake_function+0x40/0x40 [102000.450361] [<ffffffffc037689b>] cifs_oplock_break+0x6b/0x330 [cifs] [102000.450631] [<ffffffff8108f218>] process_one_work+0x158/0x460 [102000.450907] [<ffffffff8108fef3>] worker_thread+0x53/0x5a0 [102000.451163] [<ffffffff8108fea0>] ? idle_worker_timeout+0x110/0x110 [102000.451834] [<ffffffff810950e9>] kthread+0xc9/0xe0 [102000.452093] [<ffffffff81095020>] ? kthread_create_on_node+0x1c0/0x1c0 [102000.452357] [<ffffffff817cf2bc>] ret_from_fork+0x7c/0xb0 [102000.452601] [<ffffffff81095020>] ? kthread_create_on_node+0x1c0/0x1c0 The same repeats for various other processes like kworker and the hanging userspace process. This happens with all recent kernel versions (3.13-3.19) and forces us to reboot the server regularly as the requesting processes always hang with process state "D" and (I/O) load increases from day to day. Further information: Mount options: sec=krb5,multiuser,mfsymlinks,dir_mode=0700,file_mode=0700,nomapposix,noserverino,nobrl CIFS server: Samba 4.1.17 with default configuration To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1428045/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
