<div dir="ltr"><div>Hi, list<br><br></div>When I umount a DRBD device used by a DRBD client, the 'umount' program hang, and I got the following call trace:<br><br>```<br>[28076.944996] XFS (drbd100): Unmounting Filesystem<br>[28198.933553] drbd web: State change failed: Device is held open by someone<br>[28198.935451] drbd web: Failed: role( Primary -> Secondary )<br>[28200.828646] INFO: task umount:21558 blocked for more than 120 seconds.<br>[28200.830496] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.<br>[28200.831238] umount D ffff8801379fc890 0 21558 21271 0x00000084<br>[28200.831253] ffff8800a164fd90 0000000000000082 ffff880136345c00 ffff8800a164ffd8<br>[28200.831282] ffff8800a164ffd8 ffff8800a164ffd8 ffff880136345c00 ffff8801379fc880<br>[28200.831284] ffff8800a1337d10 ffff8801379fc8c0 ffff8801379fc8e8 ffff8801379fc890<br>[28200.831289] Call Trace:<br>[28200.831321] [<ffffffff8163a909>] schedule+0x29/0x70<br>[28200.831516] [<ffffffffa023fc41>] xfs_ail_push_all_sync+0xc1/0x110 [xfs]<br>[28200.831554] [<ffffffff810a6ae0>] ? wake_up_atomic_t+0x30/0x30<br>[28200.831572] [<ffffffffa022ab08>] xfs_unmountfs+0x68/0x190 [xfs]<br>[28200.831584] [<ffffffffa022b5eb>] ? xfs_mru_cache_destroy+0x6b/0x90 [xfs]<br>[28200.831597] [<ffffffffa022d9c2>] xfs_fs_put_super+0x32/0x90 [xfs]<br>[28200.831621] [<ffffffff811e0ab6>] generic_shutdown_super+0x56/0xe0<br>[28200.831623] [<ffffffff811e0f07>] kill_block_super+0x27/0x70<br>[28200.831625] [<ffffffff811e1249>] deactivate_locked_super+0x49/0x60<br>[28200.831627] [<ffffffff811e1846>] deactivate_super+0x46/0x60<br>[28200.831632] [<ffffffff811fe785>] mntput_no_expire+0xc5/0x120<br>[28200.831635] [<ffffffff811ff8bf>] SyS_umount+0x9f/0x3c0<br>[28200.831642] [<ffffffff81645909>] system_call_fastpath+0x16/0x1b<br>[28320.831678] INFO: task umount:21558 blocked for more than 120 seconds.<br>[28320.833583] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.<br>[28320.834275] umount D ffff8801379fc890 0 21558 21271 0x00000084<br>[28320.834286] ffff8800a164fd90 0000000000000082 ffff880136345c00 ffff8800a164ffd8<br>[28320.834290] ffff8800a164ffd8 ffff8800a164ffd8 ffff880136345c00 ffff8801379fc880<br>[28320.834292] ffff8800a1337d10 ffff8801379fc8c0 ffff8801379fc8e8 ffff8801379fc890<br>[28320.834295] Call Trace:<br>[28320.834349] [<ffffffff8163a909>] schedule+0x29/0x70<br>[28320.834653] [<ffffffffa023fc41>] xfs_ail_push_all_sync+0xc1/0x110 [xfs]<br>[28320.834688] [<ffffffff810a6ae0>] ? wake_up_atomic_t+0x30/0x30<br>[28320.834708] [<ffffffffa022ab08>] xfs_unmountfs+0x68/0x190 [xfs]<br>[28320.834724] [<ffffffffa022b5eb>] ? xfs_mru_cache_destroy+0x6b/0x90 [xfs]<br>[28320.834752] [<ffffffffa022d9c2>] xfs_fs_put_super+0x32/0x90 [xfs]<br>[28320.834771] [<ffffffff811e0ab6>] generic_shutdown_super+0x56/0xe0<br>[28320.834775] [<ffffffff811e0f07>] kill_block_super+0x27/0x70<br>[28320.834780] [<ffffffff811e1249>] deactivate_locked_super+0x49/0x60<br>[28320.834783] [<ffffffff811e1846>] deactivate_super+0x46/0x60<br>[28320.834791] [<ffffffff811fe785>] mntput_no_expire+0xc5/0x120<br>[28320.834795] [<ffffffff811ff8bf>] SyS_umount+0x9f/0x3c0<br>[28320.834803] [<ffffffff81645909>] system_call_fastpath+0x16/0x1<br>```<br clear="all"><div><div><div><div><br></div><div>Before umount hang, I did the following steps:<br></div><div>1. mount the drbd device at DRBD client (pure client) node;<br></div><div>2. poweroff 2 of the 3 nodes that contains the resource for the DRBD client above<br></div><div>3. write to a file under the mount point at step 1<br></div><div>4. umount the drbd device at step 1 <= umount hang<br></div><div><br></div><div>My environment:<br># cat /etc/centos-release<br>CentOS Linux release 7.2.1511 (Core)<br># rpm -qa | grep drbd<br>kmod-drbd-9.0.1_3.10.0_327-1.el7.centos.x86_64<br>drbdmanage-0.99.4-1.noarch<br>drbd-utils-8.9.11-1.el7.centos.x86_64<br></div><div><br></div><div>The call trace doesn't show anything obviously related to DRBD 9. But just in case.<br></div><div><br>-- <br><div class="gmail_signature">Thanks,<br>Li Qun<br></div>
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