Messages in this thread | | | From | Johannes Hirte <> | Subject | Re: task imap:2958 blocked for more than 120 seconds | Date | Sun, 7 Mar 2010 16:52:56 +0100 |
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Am Sonntag 10 Januar 2010 21:05:46 schrieb Johannes Hirte: > I've observed this hanging task now several times. Not sure when this > started, but 2.6.32 is affected too, IIRC. I don't have a test pattern for > this. Dovecot imap triggers this from time to time. I've enabled > CONFIG_DETECT_HUNG_TASK now and got this two tasks which hang: > > INFO: task imap:2958 blocked for more than 120 seconds. > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > imap D 0000000000000000 0 2958 2653 0x00000000 > ffff88008caf5a28 0000000000000046 0000000000000000 ffffffff810544cf > ffff88008caf5998 0000000000000001 ffff88008caf5fd8 ffff88008caf9530 > 000000000000de78 00000000001d2700 00000000001d2700 ffff88008caf9530 > Call Trace: > [<ffffffff810544cf>] ? trace_hardirqs_off+0xd/0xf > [<ffffffff8105613b>] ? trace_hardirqs_on_caller+0x10c/0x130 > [<ffffffff81071262>] ? sync_page+0x0/0x48 > [<ffffffff8138b46a>] io_schedule+0x38/0x4d > [<ffffffff810712a6>] sync_page+0x44/0x48 > [<ffffffff8138b99a>] __wait_on_bit_lock+0x41/0x8a > [<ffffffff8107124e>] __lock_page+0x61/0x68 > [<ffffffff810475a3>] ? wake_bit_function+0x0/0x2e > [<ffffffff810718c6>] filemap_fault+0xea/0x345 > [<ffffffff81084022>] __do_fault+0x50/0x3d3 > [<ffffffff81086077>] handle_mm_fault+0x32f/0x65d > [<ffffffff8102039d>] ? do_page_fault+0xf4/0x26f > [<ffffffff811cacb4>] ? __down_read_trylock+0x46/0x4e > [<ffffffff8104b0f3>] ? down_read_trylock+0x3f/0x49 > [<ffffffff8102039d>] ? do_page_fault+0xf4/0x26f > [<ffffffff81020500>] do_page_fault+0x257/0x26f > [<ffffffff8138e2ff>] page_fault+0x1f/0x30 > [<ffffffff81083a13>] ? might_fault+0x57/0xa7 > [<ffffffff811746e2>] ? btrfs_copy_from_user+0x4f/0x113 > [<ffffffff81174771>] ? btrfs_copy_from_user+0xde/0x113 > [<ffffffff81174cd0>] btrfs_file_write+0x439/0x6fe > [<ffffffff810a5c34>] vfs_write+0xad/0x14e > [<ffffffff8105613b>] ? trace_hardirqs_on_caller+0x10c/0x130 > [<ffffffff810a5d2a>] sys_pwrite64+0x55/0x74 > [<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b > 2 locks held by imap/2958: > #0: (&sb->s_type->i_mutex_key#4){+.+.+.}, at: [<ffffffff81174a00>] > btrfs_file_write+0x169/0x6fe > #1: (&mm->mmap_sem){++++++}, at: [<ffffffff8102039d>] > do_page_fault+0xf4/0x26f INFO: task flush-btrfs-2:2783 blocked for more > than 120 seconds. > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > flush-btrfs-2 D 0000000000000000 0 2783 2 0x00000000 > ffff88010cdcf9d0 0000000000000046 0000000000000000 ffffffff810544cf > ffff88010cdcf940 0000000000000000 ffff88010cdcffd8 ffff88010cd18290 > 000000000000de78 00000000001d2700 00000000001d2700 ffff88010cd18290 > Call Trace: > [<ffffffff810544cf>] ? trace_hardirqs_off+0xd/0xf > [<ffffffff8105613b>] ? trace_hardirqs_on_caller+0x10c/0x130 > [<ffffffff81071262>] ? sync_page+0x0/0x48 > [<ffffffff8138b46a>] io_schedule+0x38/0x4d > [<ffffffff810712a6>] sync_page+0x44/0x48 > [<ffffffff8138b99a>] __wait_on_bit_lock+0x41/0x8a > [<ffffffff81070ce1>] ? find_get_pages_tag+0x0/0x130 > [<ffffffff8107124e>] __lock_page+0x61/0x68 > [<ffffffff810475a3>] ? wake_bit_function+0x0/0x2e > [<ffffffff811871f6>] T.858+0xf1/0x2cd > [<ffffffff8104c4f9>] ? sched_clock_cpu+0xc6/0xd4 > [<ffffffff8104c3cd>] ? sched_clock_local+0x1c/0x82 > [<ffffffff8104c4f9>] ? sched_clock_cpu+0xc6/0xd4 > [<ffffffff810544cf>] ? trace_hardirqs_off+0xd/0xf > [<ffffffff811874d3>] extent_writepages+0x3f/0x54 > [<ffffffff8116dbd5>] ? btrfs_get_extent+0x0/0x7ee > [<ffffffff8116da7e>] btrfs_writepages+0x22/0x24 > [<ffffffff81077d12>] do_writepages+0x1f/0x28 > [<ffffffff810c0233>] writeback_single_inode+0xf1/0x2f0 > [<ffffffff810c0f57>] writeback_inodes_wb+0x3a9/0x4b2 > [<ffffffff810c118b>] wb_writeback+0x12b/0x1af > [<ffffffff810c1436>] wb_do_writeback+0x17f/0x195 > [<ffffffff810c1342>] ? wb_do_writeback+0x8b/0x195 > [<ffffffff810c1477>] bdi_writeback_task+0x2b/0x84 > [<ffffffff81082a45>] ? bdi_start_fn+0x0/0xcf > [<ffffffff81082ab6>] bdi_start_fn+0x71/0xcf > [<ffffffff81082a45>] ? bdi_start_fn+0x0/0xcf > [<ffffffff81047197>] kthread+0x7a/0x82 > [<ffffffff81002c94>] kernel_thread_helper+0x4/0x10 > [<ffffffff8138e0fc>] ? restore_args+0x0/0x30 > [<ffffffff8104711d>] ? kthread+0x0/0x82 > [<ffffffff81002c90>] ? kernel_thread_helper+0x0/0x10 > 1 lock held by flush-btrfs-2/2783: > #0: (&type->s_umount_key#20){++++..}, at: [<ffffffff810c0e82>] > writeback_inodes_wb+0x2d4/0x4b2 > > regards, > Johannes
It happend again, today I found in the logs:
INFO: task imap:2590 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. imap D ffff88002828ddf8 0 2590 2472 0x00000000 ffff88011fa53000 0000000000000086 0000000000000000 ffff8800282923a0 ffff88011b7cc480 0000000000000000 ffff880028294c58 ffff880117a5e000 00000000fffdcf81 ffff880117a5e280 0000000000012340 0000000000012340 Call Trace: [<ffffffff81061de2>] ? sync_page+0x0/0x46 [<ffffffff8134acaa>] ? io_schedule+0x35/0x48 [<ffffffff81061e23>] ? sync_page+0x41/0x46 [<ffffffff8134b185>] ? __wait_on_bit_lock+0x3c/0x85 [<ffffffff81061dcf>] ? __lock_page+0x5d/0x63 [<ffffffff81042877>] ? wake_bit_function+0x0/0x2e [<ffffffff810623da>] ? filemap_fault+0xcc/0x305 [<ffffffff810733e6>] ? __do_fault+0x52/0x3f0 [<ffffffff810753fa>] ? handle_mm_fault+0x346/0x6b6 [<ffffffff8101ecff>] ? do_page_fault+0x264/0x280 [<ffffffff8134c91f>] ? page_fault+0x1f/0x30 [<ffffffff81157b12>] ? btrfs_copy_from_user+0x50/0x109 [<ffffffff81157b94>] ? btrfs_copy_from_user+0xd2/0x109 [<ffffffff811580f5>] ? btrfs_file_write+0x448/0x6db [<ffffffff81093aff>] ? vfs_write+0xa8/0x14c [<ffffffff81093bf6>] ? sys_pwrite64+0x53/0x71 [<ffffffff81001eab>] ? system_call_fastpath+0x16/0x1b
and btrfsck said:
datengrab ~ # btrfsck /dev/mapper/sdb root 5 inode 842742 errors 400 found 186575216640 bytes used err is 1 total csum bytes: 181076596 total tree bytes: 1147568128 total fs tree bytes: 884981760 btree space waste bytes: 289677575 file data blocks allocated: 191211343872 referenced 185262080000 Btrfs v0.19-4-gab8fb4c
I was able to "fix" this by copying the affected directory to another location on the same disc, delete the old directory and rename the copy to the old one. After this the deadlock and the FS corruption was gone.
regards, Johannes
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