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[Bug 1528177] CRDA.txt

 

apport information

** Attachment added: "CRDA.txt"
   https://bugs.launchpad.net/bugs/1528177/+attachment/4538292/+files/CRDA.txt

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https://bugs.launchpad.net/bugs/1528177

Title:
  14.04.3 - btrfs  Kernel panic

Status in linux package in Ubuntu:
  New

Bug description:
  [  480.220058] INFO: task kworker/u16:1:85 blocked for more than 120 seconds.
  [  480.220067]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  480.220068] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  480.220071] kworker/u16:1   D 0000000000000000     0    85      2 0x00000000
  [  480.220120] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs]
  [  480.220123]  ffff88085b6ebae8 0000000000000046 ffff880855d8f2c0 ffff88085ba63300
  [  480.220125]  ffff88085b6ebb18 ffff88085b6ec000 ffff88080d6569e0 ffff88080d6569d8
  [  480.220127]  ffff88085ba63300 ffff880826e44178 ffff88085b6ebb08 ffffffff817b71e7
  [  480.220130] Call Trace:
  [  480.220139]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  480.220142]  [<ffffffff817b9ba1>] schedule_timeout+0x201/0x2a0
  [  480.220147]  [<ffffffff8108c0b4>] ? wake_up_worker+0x24/0x30
  [  480.220149]  [<ffffffff8108d03b>] ? insert_work+0x6b/0xb0
  [  480.220151]  [<ffffffff817b7b14>] wait_for_completion+0xa4/0x110
  [  480.220154]  [<ffffffff810a06e0>] ? wake_up_q+0x80/0x80
  [  480.220163]  [<ffffffffc037d6d7>] btrfs_async_run_delayed_refs+0x127/0x150 [btrfs]
  [  480.220174]  [<ffffffffc03987de>] __btrfs_end_transaction+0x27e/0x3d0 [btrfs]
  [  480.220183]  [<ffffffff811cc888>] ? kfree+0xf8/0x130
  [  480.220193]  [<ffffffffc0398940>] btrfs_end_transaction+0x10/0x20 [btrfs]
  [  480.220208]  [<ffffffffc03fd380>] btrfs_qgroup_rescan_worker+0xc0/0x5d0 [btrfs]
  [  480.220213]  [<ffffffff810136b3>] ? __switch_to+0x1f3/0x570
  [  480.220225]  [<ffffffffc03c74d0>] normal_work_helper+0xc0/0x280 [btrfs]
  [  480.220236]  [<ffffffffc03c78a2>] btrfs_qgroup_rescan_helper+0x12/0x20 [btrfs]
  [  480.220239]  [<ffffffff8108f4ee>] process_one_work+0x14e/0x3d0
  [  480.220241]  [<ffffffff8108fb9a>] worker_thread+0x11a/0x470
  [  480.220242]  [<ffffffff8108fa80>] ? rescuer_thread+0x310/0x310
  [  480.220245]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  480.220246]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  480.220249]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  480.220251]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  480.220289] INFO: task kworker/u16:10:1674 blocked for more than 120 seconds.
  [  480.220290]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  480.220291] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  480.220292] kworker/u16:10  D ffff88087fcd6640     0  1674      2 0x00000000
  [  480.220306] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs]
  [  480.220308]  ffff880857c8bc98 0000000000000046 ffff88085bf1b300 ffff880855d8f2c0
  [  480.220310]  0000000000000246 ffff880857c8c000 ffff88085803e1f0 ffff88085803e1f0
  [  480.220312]  0000000000000001 ffff880811308cf0 ffff880857c8bcb8 ffffffff817b71e7
  [  480.220314] Call Trace:
  [  480.220316]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  480.220326]  [<ffffffffc0396906>] wait_current_trans.isra.22+0xa6/0x110 [btrfs]
  [  480.220329]  [<ffffffff810b7370>] ? prepare_to_wait_event+0xf0/0xf0
  [  480.220339]  [<ffffffffc039824f>] start_transaction+0x37f/0x580 [btrfs]
  [  480.220350]  [<ffffffffc03984a7>] btrfs_join_transaction+0x17/0x20 [btrfs]
  [  480.220359]  [<ffffffffc0382f58>] delayed_ref_async_start+0x18/0x90 [btrfs]
  [  480.220371]  [<ffffffffc03c74d0>] normal_work_helper+0xc0/0x280 [btrfs]
  [  480.220383]  [<ffffffffc03c78c2>] btrfs_extent_refs_helper+0x12/0x20 [btrfs]
  [  480.220385]  [<ffffffff8108f4ee>] process_one_work+0x14e/0x3d0
  [  480.220386]  [<ffffffff8108fb9a>] worker_thread+0x11a/0x470
  [  480.220388]  [<ffffffff8108fa80>] ? rescuer_thread+0x310/0x310
  [  480.220390]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  480.220392]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  480.220393]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  480.220395]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  480.220469] INFO: task btrfs-cleaner:3693 blocked for more than 120 seconds.
  [  480.220471]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  480.220472] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  480.220472] btrfs-cleaner   D ffff88087fd56640     0  3693      2 0x00000000
  [  480.220475]  ffff88007a3d3ca8 0000000000000046 ffff88085bf1cc80 ffff88081fef9980
  [  480.220477]  0000000000000246 ffff88007a3d4000 ffff88085803e1f0 ffff88085803e1f0
  [  480.220479]  0000000000000001 ffff880811341508 ffff88007a3d3cc8 ffffffff817b71e7
  [  480.220482] Call Trace:
  [  480.220484]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  480.220494]  [<ffffffffc0396906>] wait_current_trans.isra.22+0xa6/0x110 [btrfs]
  [  480.220496]  [<ffffffff810b7370>] ? prepare_to_wait_event+0xf0/0xf0
  [  480.220506]  [<ffffffffc039831b>] start_transaction+0x44b/0x580 [btrfs]
  [  480.220516]  [<ffffffffc039846b>] btrfs_start_transaction+0x1b/0x20 [btrfs]
  [  480.220526]  [<ffffffffc0381576>] btrfs_drop_snapshot+0x4c6/0x830 [btrfs]
  [  480.220537]  [<ffffffffc039731c>] btrfs_clean_one_deleted_snapshot+0xbc/0x110 [btrfs]
  [  480.220546]  [<ffffffffc038fcce>] cleaner_kthread+0x14e/0x1e0 [btrfs]
  [  480.220556]  [<ffffffffc038fb80>] ? check_leaf+0x340/0x340 [btrfs]
  [  480.220558]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  480.220560]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  480.220561]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  480.220563]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  480.220566] INFO: task mc:3780 blocked for more than 120 seconds.
  [  480.220567]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  480.220568] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  480.220569] mc              D ffff88087fc96640     0  3780   3714 0x00000000
  [  480.220572]  ffff8807ff93fa08 0000000000000086 ffff88085bf1a640 ffff8808242fb300
  [  480.220575]  0000000000000246 ffff8807ff940000 ffff8807fca981f0 ffff8807fca981f0
  [  480.220577]  0000000000000001 ffff88081124d7e8 ffff8807ff93fa28 ffffffff817b71e7
  [  480.220579] Call Trace:
  [  480.220581]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  480.220591]  [<ffffffffc0396906>] wait_current_trans.isra.22+0xa6/0x110 [btrfs]
  [  480.220593]  [<ffffffff810b7370>] ? prepare_to_wait_event+0xf0/0xf0
  [  480.220603]  [<ffffffffc039831b>] start_transaction+0x44b/0x580 [btrfs]
  [  480.220614]  [<ffffffffc039846b>] btrfs_start_transaction+0x1b/0x20 [btrfs]
  [  480.220625]  [<ffffffffc03a4065>] btrfs_orphan_cleanup+0x95/0x410 [btrfs]
  [  480.220636]  [<ffffffffc03a4702>] btrfs_lookup_dentry+0x322/0x4a0 [btrfs]
  [  480.220647]  [<ffffffffc03a4896>] btrfs_lookup+0x16/0x40 [btrfs]
  [  480.220650]  [<ffffffff811f43cd>] lookup_real+0x1d/0x50
  [  480.220651]  [<ffffffff811f47f3>] __lookup_hash+0x33/0x40
  [  480.220653]  [<ffffffff811f71ff>] walk_component+0x15f/0x200
  [  480.220655]  [<ffffffff811f648c>] ? path_init+0x1ec/0x3e0
  [  480.220657]  [<ffffffff811f79d0>] path_lookupat+0x60/0x110
  [  480.220665]  [<ffffffffc037602a>] ? btrfs_next_old_leaf+0x1da/0x4a0 [btrfs]
  [  480.220668]  [<ffffffff811f9da8>] filename_lookup+0x98/0x160
  [  480.220669]  [<ffffffff811cd4a5>] ? kmem_cache_alloc+0x185/0x1f0
  [  480.220671]  [<ffffffff811f99df>] ? getname_flags+0x4f/0x1f0
  [  480.220673]  [<ffffffff811f9f2a>] user_path_at_empty+0x3a/0x50
  [  480.220676]  [<ffffffff811ef913>] vfs_fstatat+0x53/0xa0
  [  480.220679]  [<ffffffff812065a3>] ? touch_atime+0x23/0xa0
  [  480.220681]  [<ffffffff811efdd2>] SYSC_newlstat+0x22/0x40
  [  480.220684]  [<ffffffff811fe18d>] ? SyS_getdents+0x9d/0xf0
  [  480.220685]  [<ffffffff811fde60>] ? fillonedir+0xc0/0xc0
  [  480.220687]  [<ffffffff811f000e>] SyS_newlstat+0xe/0x10
  [  480.220689]  [<ffffffff817baa32>] entry_SYSCALL_64_fastpath+0x16/0x75
  [  600.220047] INFO: task kworker/u16:1:85 blocked for more than 120 seconds.
  [  600.220055]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  600.220056] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  600.220058] kworker/u16:1   D 0000000000000000     0    85      2 0x00000000
  [  600.220099] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs]
  [  600.220101]  ffff88085b6ebae8 0000000000000046 ffff880855d8f2c0 ffff88085ba63300
  [  600.220104]  ffff88085b6ebb18 ffff88085b6ec000 ffff88080d6569e0 ffff88080d6569d8
  [  600.220106]  ffff88085ba63300 ffff880826e44178 ffff88085b6ebb08 ffffffff817b71e7
  [  600.220108] Call Trace:
  [  600.220117]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  600.220119]  [<ffffffff817b9ba1>] schedule_timeout+0x201/0x2a0
  [  600.220124]  [<ffffffff8108c0b4>] ? wake_up_worker+0x24/0x30
  [  600.220126]  [<ffffffff8108d03b>] ? insert_work+0x6b/0xb0
  [  600.220128]  [<ffffffff817b7b14>] wait_for_completion+0xa4/0x110
  [  600.220131]  [<ffffffff810a06e0>] ? wake_up_q+0x80/0x80
  [  600.220140]  [<ffffffffc037d6d7>] btrfs_async_run_delayed_refs+0x127/0x150 [btrfs]
  [  600.220151]  [<ffffffffc03987de>] __btrfs_end_transaction+0x27e/0x3d0 [btrfs]
  [  600.220154]  [<ffffffff811cc888>] ? kfree+0xf8/0x130
  [  600.220164]  [<ffffffffc0398940>] btrfs_end_transaction+0x10/0x20 [btrfs]
  [  600.220178]  [<ffffffffc03fd380>] btrfs_qgroup_rescan_worker+0xc0/0x5d0 [btrfs]
  [  600.220182]  [<ffffffff810136b3>] ? __switch_to+0x1f3/0x570
  [  600.220194]  [<ffffffffc03c74d0>] normal_work_helper+0xc0/0x280 [btrfs]
  [  600.220206]  [<ffffffffc03c78a2>] btrfs_qgroup_rescan_helper+0x12/0x20 [btrfs]
  [  600.220208]  [<ffffffff8108f4ee>] process_one_work+0x14e/0x3d0
  [  600.220210]  [<ffffffff8108fb9a>] worker_thread+0x11a/0x470
  [  600.220212]  [<ffffffff8108fa80>] ? rescuer_thread+0x310/0x310
  [  600.220214]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  600.220216]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  600.220218]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  600.220220]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  600.220251] INFO: task kworker/u16:10:1674 blocked for more than 120 seconds.
  [  600.220252]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  600.220253] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  600.220254] kworker/u16:10  D ffff88087fcd6640     0  1674      2 0x00000000
  [  600.220268] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs]
  [  600.220269]  ffff880857c8bc98 0000000000000046 ffff88085bf1b300 ffff880855d8f2c0
  [  600.220272]  0000000000000246 ffff880857c8c000 ffff88085803e1f0 ffff88085803e1f0
  [  600.220274]  0000000000000001 ffff880811308cf0 ffff880857c8bcb8 ffffffff817b71e7
  [  600.220276] Call Trace:
  [  600.220278]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  600.220288]  [<ffffffffc0396906>] wait_current_trans.isra.22+0xa6/0x110 [btrfs]
  [  600.220291]  [<ffffffff810b7370>] ? prepare_to_wait_event+0xf0/0xf0
  [  600.220301]  [<ffffffffc039824f>] start_transaction+0x37f/0x580 [btrfs]
  [  600.220311]  [<ffffffffc03984a7>] btrfs_join_transaction+0x17/0x20 [btrfs]
  [  600.220320]  [<ffffffffc0382f58>] delayed_ref_async_start+0x18/0x90 [btrfs]
  [  600.220332]  [<ffffffffc03c74d0>] normal_work_helper+0xc0/0x280 [btrfs]
  [  600.220343]  [<ffffffffc03c78c2>] btrfs_extent_refs_helper+0x12/0x20 [btrfs]
  [  600.220345]  [<ffffffff8108f4ee>] process_one_work+0x14e/0x3d0
  [  600.220347]  [<ffffffff8108fb9a>] worker_thread+0x11a/0x470
  [  600.220349]  [<ffffffff8108fa80>] ? rescuer_thread+0x310/0x310
  [  600.220351]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  600.220352]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  600.220354]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  600.220356]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  600.220415] INFO: task btrfs-cleaner:3693 blocked for more than 120 seconds.
  [  600.220416]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  600.220417] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  600.220418] btrfs-cleaner   D ffff88087fd56640     0  3693      2 0x00000000
  [  600.220421]  ffff88007a3d3ca8 0000000000000046 ffff88085bf1cc80 ffff88081fef9980
  [  600.220423]  0000000000000246 ffff88007a3d4000 ffff88085803e1f0 ffff88085803e1f0
  [  600.220425]  0000000000000001 ffff880811341508 ffff88007a3d3cc8 ffffffff817b71e7
  [  600.220427] Call Trace:
  [  600.220429]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  600.220439]  [<ffffffffc0396906>] wait_current_trans.isra.22+0xa6/0x110 [btrfs]
  [  600.220441]  [<ffffffff810b7370>] ? prepare_to_wait_event+0xf0/0xf0
  [  600.220451]  [<ffffffffc039831b>] start_transaction+0x44b/0x580 [btrfs]
  [  600.220461]  [<ffffffffc039846b>] btrfs_start_transaction+0x1b/0x20 [btrfs]
  [  600.220470]  [<ffffffffc0381576>] btrfs_drop_snapshot+0x4c6/0x830 [btrfs]
  [  600.220481]  [<ffffffffc039731c>] btrfs_clean_one_deleted_snapshot+0xbc/0x110 [btrfs]
  [  600.220490]  [<ffffffffc038fcce>] cleaner_kthread+0x14e/0x1e0 [btrfs]
  [  600.220499]  [<ffffffffc038fb80>] ? check_leaf+0x340/0x340 [btrfs]
  [  600.220501]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  600.220503]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  600.220505]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  600.220506]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  600.220509] INFO: task mc:3780 blocked for more than 120 seconds.
  [  600.220510]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  600.220511] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  600.220512] mc              D ffff88087fc96640     0  3780   3714 0x00000000
  [  600.220515]  ffff8807ff93fa08 0000000000000086 ffff88085bf1a640 ffff8808242fb300
  [  600.220517]  0000000000000246 ffff8807ff940000 ffff8807fca981f0 ffff8807fca981f0
  [  600.220519]  0000000000000001 ffff88081124d7e8 ffff8807ff93fa28 ffffffff817b71e7
  [  600.220521] Call Trace:
  [  600.220523]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  600.220533]  [<ffffffffc0396906>] wait_current_trans.isra.22+0xa6/0x110 [btrfs]
  [  600.220535]  [<ffffffff810b7370>] ? prepare_to_wait_event+0xf0/0xf0
  [  600.220545]  [<ffffffffc039831b>] start_transaction+0x44b/0x580 [btrfs]
  [  600.220555]  [<ffffffffc039846b>] btrfs_start_transaction+0x1b/0x20 [btrfs]
  [  600.220566]  [<ffffffffc03a4065>] btrfs_orphan_cleanup+0x95/0x410 [btrfs]
  [  600.220577]  [<ffffffffc03a4702>] btrfs_lookup_dentry+0x322/0x4a0 [btrfs]
  [  600.220587]  [<ffffffffc03a4896>] btrfs_lookup+0x16/0x40 [btrfs]
  [  600.220590]  [<ffffffff811f43cd>] lookup_real+0x1d/0x50
  [  600.220592]  [<ffffffff811f47f3>] __lookup_hash+0x33/0x40
  [  600.220594]  [<ffffffff811f71ff>] walk_component+0x15f/0x200
  [  600.220595]  [<ffffffff811f648c>] ? path_init+0x1ec/0x3e0
  [  600.220597]  [<ffffffff811f79d0>] path_lookupat+0x60/0x110
  [  600.220606]  [<ffffffffc037602a>] ? btrfs_next_old_leaf+0x1da/0x4a0 [btrfs]
  [  600.220608]  [<ffffffff811f9da8>] filename_lookup+0x98/0x160
  [  600.220610]  [<ffffffff811cd4a5>] ? kmem_cache_alloc+0x185/0x1f0
  [  600.220611]  [<ffffffff811f99df>] ? getname_flags+0x4f/0x1f0
  [  600.220613]  [<ffffffff811f9f2a>] user_path_at_empty+0x3a/0x50
  [  600.220616]  [<ffffffff811ef913>] vfs_fstatat+0x53/0xa0
  [  600.220619]  [<ffffffff812065a3>] ? touch_atime+0x23/0xa0
  [  600.220621]  [<ffffffff811efdd2>] SYSC_newlstat+0x22/0x40
  [  600.220624]  [<ffffffff811fe18d>] ? SyS_getdents+0x9d/0xf0
  [  600.220625]  [<ffffffff811fde60>] ? fillonedir+0xc0/0xc0
  [  600.220627]  [<ffffffff811f000e>] SyS_newlstat+0xe/0x10
  [  600.220629]  [<ffffffff817baa32>] entry_SYSCALL_64_fastpath+0x16/0x75
  [  720.220052] INFO: task kworker/u16:1:85 blocked for more than 120 seconds.
  [  720.220061]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  720.220062] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  720.220064] kworker/u16:1   D 0000000000000000     0    85      2 0x00000000
  [  720.220104] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs]
  [  720.220106]  ffff88085b6ebae8 0000000000000046 ffff880855d8f2c0 ffff88085ba63300
  [  720.220109]  ffff88085b6ebb18 ffff88085b6ec000 ffff88080d6569e0 ffff88080d6569d8
  [  720.220111]  ffff88085ba63300 ffff880826e44178 ffff88085b6ebb08 ffffffff817b71e7
  [  720.220113] Call Trace:
  [  720.220122]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  720.220125]  [<ffffffff817b9ba1>] schedule_timeout+0x201/0x2a0
  [  720.220129]  [<ffffffff8108c0b4>] ? wake_up_worker+0x24/0x30
  [  720.220131]  [<ffffffff8108d03b>] ? insert_work+0x6b/0xb0
  [  720.220133]  [<ffffffff817b7b14>] wait_for_completion+0xa4/0x110
  [  720.220136]  [<ffffffff810a06e0>] ? wake_up_q+0x80/0x80
  [  720.220146]  [<ffffffffc037d6d7>] btrfs_async_run_delayed_refs+0x127/0x150 [btrfs]
  [  720.220156]  [<ffffffffc03987de>] __btrfs_end_transaction+0x27e/0x3d0 [btrfs]
  [  720.220160]  [<ffffffff811cc888>] ? kfree+0xf8/0x130
  [  720.220170]  [<ffffffffc0398940>] btrfs_end_transaction+0x10/0x20 [btrfs]
  [  720.220188]  [<ffffffffc03fd380>] btrfs_qgroup_rescan_worker+0xc0/0x5d0 [btrfs]
  [  720.220194]  [<ffffffff810136b3>] ? __switch_to+0x1f3/0x570
  [  720.220206]  [<ffffffffc03c74d0>] normal_work_helper+0xc0/0x280 [btrfs]
  [  720.220218]  [<ffffffffc03c78a2>] btrfs_qgroup_rescan_helper+0x12/0x20 [btrfs]
  [  720.220220]  [<ffffffff8108f4ee>] process_one_work+0x14e/0x3d0
  [  720.220222]  [<ffffffff8108fb9a>] worker_thread+0x11a/0x470
  [  720.220224]  [<ffffffff8108fa80>] ? rescuer_thread+0x310/0x310
  [  720.220226]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  720.220228]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  720.220231]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  720.220232]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  720.220262] INFO: task kworker/u16:10:1674 blocked for more than 120 seconds.
  [  720.220263]       Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [  720.220264] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  720.220265] kworker/u16:10  D ffff88087fcd6640     0  1674      2 0x00000000
  [  720.220279] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs]
  [  720.220280]  ffff880857c8bc98 0000000000000046 ffff88085bf1b300 ffff880855d8f2c0
  [  720.220282]  0000000000000246 ffff880857c8c000 ffff88085803e1f0 ffff88085803e1f0
  [  720.220285]  0000000000000001 ffff880811308cf0 ffff880857c8bcb8 ffffffff817b71e7
  [  720.220287] Call Trace:
  [  720.220289]  [<ffffffff817b71e7>] schedule+0x37/0x80
  [  720.220299]  [<ffffffffc0396906>] wait_current_trans.isra.22+0xa6/0x110 [btrfs]
  [  720.220302]  [<ffffffff810b7370>] ? prepare_to_wait_event+0xf0/0xf0
  [  720.220312]  [<ffffffffc039824f>] start_transaction+0x37f/0x580 [btrfs]
  [  720.220322]  [<ffffffffc03984a7>] btrfs_join_transaction+0x17/0x20 [btrfs]
  [  720.220331]  [<ffffffffc0382f58>] delayed_ref_async_start+0x18/0x90 [btrfs]
  [  720.220343]  [<ffffffffc03c74d0>] normal_work_helper+0xc0/0x280 [btrfs]
  [  720.220354]  [<ffffffffc03c78c2>] btrfs_extent_refs_helper+0x12/0x20 [btrfs]
  [  720.220356]  [<ffffffff8108f4ee>] process_one_work+0x14e/0x3d0
  [  720.220358]  [<ffffffff8108fb9a>] worker_thread+0x11a/0x470
  [  720.220360]  [<ffffffff8108fa80>] ? rescuer_thread+0x310/0x310
  [  720.220361]  [<ffffffff81095132>] kthread+0xd2/0xf0
  [  720.220363]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  720.220365]  [<ffffffff817bae5f>] ret_from_fork+0x3f/0x70
  [  720.220366]  [<ffffffff81095060>] ? kthread_create_on_node+0x1c0/0x1c0
  [  829.281261] perf interrupt took too long (5007 > 5000), lowering kernel.perf_event_max_sample_rate to 25000
  [ 1356.838850] ------------[ cut here ]------------
  [ 1356.838865] WARNING: CPU: 7 PID: 0 at /build/linux-lts-wily-7IMwjV/linux-lts-wily-4.2.0/kernel/workqueue.c:1318 __queue_work+0x256/0x300()
  [ 1356.838866] Modules linked in: ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_CHECKSUM iptable_mangle xt_tcpudp bridge stp llc ebtable_nat ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables rfcomm bnep bluetooth binfmt_misc input_leds ipmi_devintf gpio_ich i5000_edac dcdbas edac_core ipmi_ssif ioatdma coretemp kvm_intel i5k_amb ipmi_si kvm ipmi_msghandler dca lpc_ich serio_raw 8250_fintek shpchp mac_hid parport_pc ppdev lp parport btrfs xor raid6_pq hid_generic usbhid hid uas usb_storage amdkfd amd_iommu_v2 radeon i2c_algo_bit ttm drm_kms_helper psmouse drm mptsas pata_acpi mptscsih mptbase scsi_transport_sas bnx2
  [ 1356.838916] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 4.2.0-21-generic #25~14.04.1-Ubuntu
  [ 1356.838917] Hardware name: Dell Inc. PowerEdge 2950/0H603H, BIOS 2.7.0 10/30/2010
  [ 1356.838919]  ffffffff81a992c8 ffff88087fdc3bd8 ffffffff817b36a3 0000000000000000
  [ 1356.838921]  0000000000000000 ffff88087fdc3c18 ffffffff8107738a ffff88087fdc3c28
  [ 1356.838923]  0000000000000296 ffff88078ecb5ef0 0000000000000100 ffff88085aadaf90
  [ 1356.838926] Call Trace:
  [ 1356.838927]  <IRQ>  [<ffffffff817b36a3>] dump_stack+0x45/0x57
  [ 1356.838935]  [<ffffffff8107738a>] warn_slowpath_common+0x8a/0xc0
  [ 1356.838937]  [<ffffffff8107747a>] warn_slowpath_null+0x1a/0x20
  [ 1356.838939]  [<ffffffff8108d2d6>] __queue_work+0x256/0x300
  [ 1356.838941]  [<ffffffff8108d55b>] queue_work_on+0x2b/0x50
  [ 1356.838971]  [<ffffffffc03c7b14>] btrfs_queue_work+0x84/0xd0 [btrfs]
  [ 1356.838981]  [<ffffffffc038da76>] end_workqueue_bio+0x86/0xe0 [btrfs]
  [ 1356.838985]  [<ffffffff81372438>] bio_endio+0x58/0x90
  [ 1356.838999]  [<ffffffffc0408716>] ? btrfs_bio_counter_sub+0x26/0x60 [btrfs]
  [ 1356.839010]  [<ffffffffc03c27c3>] btrfs_end_bio+0xf3/0x160 [btrfs]
  [ 1356.839012]  [<ffffffff81372438>] bio_endio+0x58/0x90
  [ 1356.839015]  [<ffffffff813793ea>] blk_update_request+0x8a/0x320
  [ 1356.839019]  [<ffffffff81552114>] scsi_end_request+0x34/0x1d0
  [ 1356.839021]  [<ffffffff8155464e>] scsi_io_completion+0xfe/0x600
  [ 1356.839024]  [<ffffffff810ac89e>] ? enqueue_entity+0x49e/0xcb0
  [ 1356.839027]  [<ffffffff8154b88f>] scsi_finish_command+0xcf/0x120
  [ 1356.839029]  [<ffffffff81553e76>] scsi_softirq_done+0x126/0x150
  [ 1356.839032]  [<ffffffff8137fc7c>] blk_done_softirq+0x7c/0x90
  [ 1356.839034]  [<ffffffff8107b3d2>] __do_softirq+0xd2/0x250
  [ 1356.839036]  [<ffffffff8107b785>] irq_exit+0x95/0xa0
  [ 1356.839039]  [<ffffffff8104a8f5>] smp_call_function_single_interrupt+0x35/0x40
  [ 1356.839042]  [<ffffffff817bbddb>] call_function_single_interrupt+0x6b/0x70
  [ 1356.839043]  <EOI>  [<ffffffff8101ef09>] ? mwait_idle+0xb9/0x150
  [ 1356.839049]  [<ffffffff8101f45f>] arch_cpu_idle+0xf/0x20
  [ 1356.839051]  [<ffffffff810b769b>] default_idle_call+0x3b/0x50
  [ 1356.839052]  [<ffffffff810b79de>] cpu_startup_entry+0x2be/0x330
  [ 1356.839054]  [<ffffffff8104b1a5>] start_secondary+0x175/0x1a0
  [ 1356.839056] ---[ end trace ee2f11df6ad0b827 ]---




  ProblemType: Bug
  DistroRelease: elementary OS 0.3.2
  Package: linux-image-4.2.0-21-generic 4.2.0-21.25~14.04.1 [origin: Ubuntu]
  ProcVersionSignature: Ubuntu 4.2.0-21.25~14.04.1-generic 4.2.6
  Uname: Linux 4.2.0-21-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3.19
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Mon Dec 21 11:51:27 2015
  InstallationDate: Installed on 2015-09-22 (90 days ago)
  InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
  SourcePackage: linux-lts-wily
  UpgradeStatus: No upgrade log present (probably fresh install)
  --- 
  ApportVersion: 2.14.1-0ubuntu3.19
  Architecture: amd64
  AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
  DistroRelease: elementary OS 0.3.2
  HibernationDevice: RESUME=UUID=8f157845-797a-4638-a830-e024456ace95
  InstallationDate: Installed on 2015-09-22 (90 days ago)
  InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
  MachineType: Dell Inc. PowerEdge 2950
  Package: linux (not installed)
  ProcEnviron:
   LANGUAGE=de_DE
   TERM=xterm
   PATH=(custom, no user)
   LANG=de_DE.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 radeondrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.2.0-21-generic root=UUID=8abc8460-a790-4cff-b008-1e7f283088a0 ro rootflags=subvol=@ quiet splash vt.handoff=7
  ProcVersionSignature: Ubuntu 4.2.0-21.25~14.04.1-generic 4.2.6
  PulseList:
   Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
   No PulseAudio daemon running, or not running as session daemon.
  RelatedPackageVersions:
   linux-restricted-modules-4.2.0-21-generic N/A
   linux-backports-modules-4.2.0-21-generic  N/A
   linux-firmware                            1.127.19
  RfKill:
   
  Tags:  freya
  Uname: Linux 4.2.0-21-generic x86_64
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups:
   
  _MarkForUpload: True
  dmi.bios.date: 10/30/2010
  dmi.bios.vendor: Dell Inc.
  dmi.bios.version: 2.7.0
  dmi.board.name: 0H603H
  dmi.board.vendor: Dell Inc.
  dmi.board.version: A06
  dmi.chassis.type: 23
  dmi.chassis.vendor: Dell Inc.
  dmi.modalias: dmi:bvnDellInc.:bvr2.7.0:bd10/30/2010:svnDellInc.:pnPowerEdge2950:pvr:rvnDellInc.:rn0H603H:rvrA06:cvnDellInc.:ct23:cvr:
  dmi.product.name: PowerEdge 2950
  dmi.sys.vendor: Dell Inc.

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