task btrfs-cleaner:770 blocked for more than 120 seconds.

task btrfs-cleaner:770 blocked for more than 120 seconds.

[Михаил Гаврилов]

Hi all! I have problem with hanging btrfs file system.

[17047.652816] INFO: task btrfs-cleaner:770 blocked for more than 120 seconds.
[17047.652837]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.652853] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.652875] btrfs-cleaner   D ffff8807fe3d7a18 10264   770      2 0x00000080
[17047.652880]  ffff8807e50f7a50 0000000000000092 ffffffff811067cd
ffff880700000000
[17047.652882]  ffff8807fa344000 ffff8807e68ec000 ffff8807e50f8000
ffff880003753e90
[17047.652884]  ffff8807e68ec000 ffff8807e68ec000 ffff8807e50f7a90
ffff8807e50f7a68
[17047.652886] Call Trace:
[17047.652891]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.652894]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.652909]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
[17047.652912]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
[17047.652918]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
[17047.652923]  [<ffffffffa06e15e9>] btrfs_search_forward+0x59/0x350 [btrfs]
[17047.652927]  [<ffffffff81247cb1>] ? kmem_cache_alloc+0x281/0x310
[17047.652931]  [<ffffffffa06d92aa>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[17047.652940]  [<ffffffffa073c946>]
find_new_extents.constprop.43+0xa6/0x2d0 [btrfs]
[17047.652942]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
[17047.652943]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.652952]  [<ffffffffa0740418>] btrfs_defrag_file+0x8d8/0xd60 [btrfs]
[17047.652955]  [<ffffffff81270ad9>] ? __sb_start_write+0xc9/0x110
[17047.652963]  [<ffffffffa07197b2>] btrfs_run_defrag_inodes+0x242/0x390 [btrfs]
[17047.652971]  [<ffffffffa0719660>] ?
btrfs_run_defrag_inodes+0xf0/0x390 [btrfs]
[17047.652978]  [<ffffffffa06fce1b>] cleaner_kthread+0xcb/0x210 [btrfs]
[17047.652984]  [<ffffffffa06fcd50>] ?
btree_read_extent_buffer_pages.constprop.54+0x110/0x110 [btrfs]
[17047.652986]  [<ffffffff810d1351>] kthread+0x101/0x120
[17047.652987]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
[17047.652989]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
[17047.652991]  [<ffffffff818673af>] ret_from_fork+0x3f/0x70
[17047.652992]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
[17047.652993] 1 lock held by btrfs-cleaner/770:
[17047.652994]  #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff81270ad9>]
__sb_start_write+0xc9/0x110
[17047.652999] INFO: task btrfs-transacti:771 blocked for more than 120 seconds.
[17047.653019]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.653032] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.653053] btrfs-transacti D ffff8807fe1d7a18  9912   771      2 0x00000080
[17047.653056]  ffff8807e50fbb20 0000000000000096 ffffffff811067cd
ffff880700000000
[17047.653058]  ffff8807fa33c000 ffff8807f7140000 ffff8807e50fc000
ffff880003753e90
[17047.653060]  ffff8807f7140000 ffff8807f7140000 ffff8807e50fbb60
ffff8807e50fbb38
[17047.653062] Call Trace:
[17047.653063]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.653065]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.653074]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
[17047.653076]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
[17047.653081]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
[17047.653086]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
[17047.653092]  [<ffffffffa06e04c1>] btrfs_insert_empty_items+0x71/0xc0 [btrfs]
[17047.653101]  [<ffffffffa075e9e5>]
__btrfs_run_delayed_items+0x135/0x600 [btrfs]
[17047.653104]  [<ffffffff810e5e8c>] ? local_clock+0x1c/0x20
[17047.653113]  [<ffffffffa075f4f3>] btrfs_run_delayed_items+0x13/0x20 [btrfs]
[17047.653120]  [<ffffffffa0705fc0>]
btrfs_commit_transaction+0x2f0/0xbd0 [btrfs]
[17047.653127]  [<ffffffffa0700f48>] transaction_kthread+0x208/0x270 [btrfs]
[17047.653134]  [<ffffffffa0700d40>] ?
btrfs_cleanup_transaction+0x610/0x610 [btrfs]
[17047.653135]  [<ffffffff810d1351>] kthread+0x101/0x120
[17047.653137]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
[17047.653138]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
[17047.653140]  [<ffffffff818673af>] ret_from_fork+0x3f/0x70
[17047.653141]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
[17047.653142] 2 locks held by btrfs-transacti/771:
[17047.653143]  #0:  (&fs_info->transaction_kthread_mutex){+.+...},
at: [<ffffffffa0700db2>] transaction_kthread+0x72/0x270 [btrfs]
[17047.653151]  #1:  (&delayed_node->mutex){+.+.-.}, at:
[<ffffffffa075e9ac>] __btrfs_run_delayed_items+0xfc/0x600 [btrfs]
[17047.653190] INFO: task systemd:2059 blocked for more than 120 seconds.
[17047.653209]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.653225] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.653246] systemd         D ffff8807fe5d7a18 12696  2059      1 0x00000000
[17047.653250]  ffff8807f6d9f9b8 0000000000000082 ffffffff81f62300
0000000000000004
[17047.653252]  ffff880725b84000 ffff8807c0afc000 ffff8807f6da0000
ffff880003753e90
[17047.653253]  ffff8807c0afc000 ffff8807c0afc000 ffff8807f6d9f9f8
ffff8807f6d9f9d0
[17047.653255] Call Trace:
[17047.653257]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.653266]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
[17047.653268]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
[17047.653273]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
[17047.653278]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
[17047.653286]  [<ffffffffa0782058>] ? btrfs_crc32c+0x68/0x90 [btrfs]
[17047.653292]  [<ffffffffa06f7b68>] btrfs_lookup_dir_item+0x78/0xc0 [btrfs]
[17047.653300]  [<ffffffffa0713ab6>] btrfs_lookup_dentry+0xb6/0x550 [btrfs]
[17047.653302]  [<ffffffff81866597>] ? _raw_spin_unlock+0x27/0x40
[17047.653309]  [<ffffffffa0713f62>] btrfs_lookup+0x12/0x40 [btrfs]
[17047.653311]  [<ffffffff81277dcd>] lookup_real+0x1d/0x60
[17047.653312]  [<ffffffff81278d72>] __lookup_hash+0x42/0x60
[17047.653314]  [<ffffffff8127c2ef>] walk_component+0x1df/0x2a0
[17047.653315]  [<ffffffff8127c540>] link_path_walk+0x190/0x5a0
[17047.653317]  [<ffffffff8127bb57>] ? path_init+0x557/0x800
[17047.653318]  [<ffffffff8127bb0f>] ? path_init+0x50f/0x800
[17047.653319]  [<ffffffff8127cb8b>] path_openat+0xab/0x1260
[17047.653321]  [<ffffffff81025c09>] ? sched_clock+0x9/0x10
[17047.653323]  [<ffffffff810e5e8c>] ? local_clock+0x1c/0x20
[17047.653325]  [<ffffffff8127f1a1>] do_filp_open+0x91/0x100
[17047.653326]  [<ffffffff81866597>] ? _raw_spin_unlock+0x27/0x40
[17047.653328]  [<ffffffff8128f56f>] ? __alloc_fd+0xaf/0x180
[17047.653330]  [<ffffffff8126cb9a>] do_sys_open+0x13a/0x230
[17047.653332]  [<ffffffff8126ccae>] SyS_open+0x1e/0x20
[17047.653333]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
[17047.653335] 1 lock held by systemd/2059:
[17047.653335]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
[<ffffffff8127c2e0>] walk_component+0x1d0/0x2a0
[17047.653345] INFO: task gnome-shell:2455 blocked for more than 120 seconds.
[17047.653362]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.653377] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.653398] gnome-shell     D ffff8807fe3d7a18 11064  2455   2276 0x00000000
[17047.653401]  ffff8807b48cfb70 0000000000000096 ffff8807b5a64928
ffff880700000000
[17047.653403]  ffff8807fa344000 ffff8807b5a64000 ffff8807b48d0000
0000000000000246
[17047.653405]  ffff8807e5fa0cd0 ffff8807b5a64000 00000000ffffffff
ffff8807b48cfb88
[17047.653407] Call Trace:
[17047.653408]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.653410]  [<ffffffff81860995>] schedule_preempt_disabled+0x15/0x20
[17047.653412]  [<ffffffff81863390>] mutex_lock_nested+0x190/0x400
[17047.653413]  [<ffffffff8127c2e0>] ? walk_component+0x1d0/0x2a0
[17047.653414]  [<ffffffff8127c2e0>] ? walk_component+0x1d0/0x2a0
[17047.653416]  [<ffffffff8127c2e0>] walk_component+0x1d0/0x2a0
[17047.653417]  [<ffffffff8127c540>] link_path_walk+0x190/0x5a0
[17047.653419]  [<ffffffff8127bb57>] ? path_init+0x557/0x800
[17047.653420]  [<ffffffff8127bb0f>] ? path_init+0x50f/0x800
[17047.653421]  [<ffffffff8127ca4c>] path_lookupat+0x7c/0x110
[17047.653422]  [<ffffffff8127e5a1>] filename_lookup+0xb1/0x180
[17047.653426]  [<ffffffff811258bd>] ? rcu_read_lock_sched_held+0x6d/0x80
[17047.653428]  [<ffffffff81247cb1>] ? kmem_cache_alloc+0x281/0x310
[17047.653429]  [<ffffffff8127e1a6>] ? getname_flags+0x56/0x1f0
[17047.653432]  [<ffffffff81025c09>] ? sched_clock+0x9/0x10
[17047.653433]  [<ffffffff8127e746>] user_path_at_empty+0x36/0x40
[17047.653435]  [<ffffffff81272aa6>] vfs_fstatat+0x66/0xc0
[17047.653436]  [<ffffffff8127303e>] SYSC_newstat+0x2e/0x60
[17047.653439]  [<ffffffff8106e6a8>] ? __do_page_fault+0x1e8/0x470
[17047.653441]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
[17047.653443]  [<ffffffff81003044>] ? lockdep_sys_exit_thunk+0x12/0x14
[17047.653445]  [<ffffffff812731ce>] SyS_newstat+0xe/0x10
[17047.653446]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
[17047.653448] 1 lock held by gnome-shell/2455:
[17047.653448]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
[<ffffffff8127c2e0>] walk_component+0x1d0/0x2a0
[17047.653471] INFO: task htop:3020 blocked for more than 120 seconds.
[17047.653488]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.653502] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.653523] htop            D ffff8807fddd7a18 11800  3020   2972 0x00000000
[17047.653527]  ffff88078866bcb8 0000000000000082 ffffffffffffffff
ffff880700000000
[17047.653529]  ffffffff81e12500 ffff88078b5dc000 ffff88078866c000
ffff8807c0b66eb0
[17047.653530]  ffffffffffffffff ffff8807c0b66ec8 ffff8807c0b66e00
ffff88078866bcd0
[17047.653532] Call Trace:
[17047.653534]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.653536]  [<ffffffff81864aff>] rwsem_down_read_failed+0xcf/0x140
[17047.653539]  [<ffffffff8142af54>] call_rwsem_down_read_failed+0x14/0x30
[17047.653541]  [<ffffffff81864363>] ? down_read+0x83/0xa0
[17047.653544]  [<ffffffff812ec931>] ? proc_pid_cmdline_read+0xb1/0x560
[17047.653546]  [<ffffffff812ec931>] proc_pid_cmdline_read+0xb1/0x560
[17047.653547]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
[17047.653549]  [<ffffffff8126cf57>] __vfs_read+0x37/0x100
[17047.653551]  [<ffffffff813936b3>] ? security_file_permission+0xa3/0xc0
[17047.653553]  [<ffffffff8126da66>] vfs_read+0x86/0x130
[17047.653554]  [<ffffffff8126e7e8>] SyS_read+0x58/0xd0
[17047.653555]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
[17047.653557] 1 lock held by htop/3020:
[17047.653557]  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff812ec931>]
proc_pid_cmdline_read+0xb1/0x560
[17047.653563] INFO: task SQLyog.exe:3780 blocked for more than 120 seconds.
[17047.653579]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.653595] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.653616] SQLyog.exe      D ffff8807fe1d7a18 11192  3780   3069 0x00000000
[17047.653619]  ffff8807384f7c90 0000000000000092 ffffffff811067cd
ffff880700000000
[17047.653621]  ffff8807fa33c000 ffff88073854c000 ffff8807384f8000
ffff880003753e90
[17047.653623]  ffff88073854c000 ffff88073854c000 ffff8807384f7cd0
ffff8807384f7ca8
[17047.653624] Call Trace:
[17047.653626]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.653628]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.653637]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
[17047.653639]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
[17047.653644]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
[17047.653649]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
[17047.653650]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.653652]  [<ffffffff81863ebe>] ? mutex_unlock+0xe/0x10
[17047.653659]  [<ffffffffa070a819>] btrfs_real_readdir+0xe9/0x590 [btrfs]
[17047.653662]  [<ffffffff81282d37>] iterate_dir+0x97/0x130
[17047.653663]  [<ffffffff8128328a>] SyS_getdents+0x9a/0x130
[17047.653664]  [<ffffffff81282ed0>] ? fillonedir+0x100/0x100
[17047.653666]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
[17047.653667] 1 lock held by SQLyog.exe/3780:
[17047.653668]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
[<ffffffff81282d01>] iterate_dir+0x61/0x130
[17047.653677] INFO: task chrome:3329 blocked for more than 120 seconds.
[17047.653694]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.653710] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.653728] chrome          D ffff8807fe3d7a18 11432  3329   3267 0x00000000
[17047.653732]  ffff88076ea27dc8 0000000000000086 ffffffffffffffff
ffff880700000000
[17047.653734]  ffff8807fa344000 ffff8807706f4000 ffff88076ea28000
ffff8807f4ab00b0
[17047.653735]  ffffffffffffffff ffff8807f4ab00c8 ffff8807706f4000
ffff88076ea27de0
[17047.653737] Call Trace:
[17047.653739]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.653741]  [<ffffffff81864aff>] rwsem_down_read_failed+0xcf/0x140
[17047.653743]  [<ffffffff8142af54>] call_rwsem_down_read_failed+0x14/0x30
[17047.653745]  [<ffffffff81864363>] ? down_read+0x83/0xa0
[17047.653746]  [<ffffffff8106e89c>] ? __do_page_fault+0x3dc/0x470
[17047.653748]  [<ffffffff8106e89c>] __do_page_fault+0x3dc/0x470
[17047.653749]  [<ffffffff8126daf7>] ? vfs_read+0x117/0x130
[17047.653751]  [<ffffffff8106e95f>] do_page_fault+0x2f/0x80
[17047.653753]  [<ffffffff81869478>] page_fault+0x28/0x30
[17047.653754] 1 lock held by chrome/3329:
[17047.653755]  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8106e89c>]
__do_page_fault+0x3dc/0x470
[17047.653774] INFO: task BrowserBlocking:3499 blocked for more than
120 seconds.
[17047.653792]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.653807] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.653828] BrowserBlocking D ffff8807fddd7a18 10840  3499   3267 0x00000000
[17047.653832]  ffff880767137658 0000000000000086 ffffffff811067cd
ffff880700000000
[17047.653834]  ffffffff81e12500 ffff8807c0ac0000 ffff880767138000
ffff880003753e90
[17047.653835]  ffff8807c0ac0000 ffff8807c0ac0000 ffff880767137698
ffff880767137670
[17047.653837] Call Trace:
[17047.653839]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.653841]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.653850]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
[17047.653851]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
[17047.653856]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
[17047.653861]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
[17047.653868]  [<ffffffffa06f8959>] btrfs_lookup_file_extent+0x49/0x60 [btrfs]
[17047.653876]  [<ffffffffa071a935>] __btrfs_drop_extents+0x185/0xd90 [btrfs]
[17047.653878]  [<ffffffff8112515d>] ? debug_lockdep_rcu_enabled+0x1d/0x20
[17047.653885]  [<ffffffffa0706931>] ? start_transaction+0x91/0x610 [btrfs]
[17047.653893]  [<ffffffffa070cac6>] cow_file_range_inline+0x1b6/0x690 [btrfs]
[17047.653901]  [<ffffffffa0724c62>] ? __set_extent_bit+0x472/0x570 [btrfs]
[17047.653909]  [<ffffffffa070d2ee>] cow_file_range+0x34e/0x440 [btrfs]
[17047.653911]  [<ffffffff81866597>] ? _raw_spin_unlock+0x27/0x40
[17047.653919]  [<ffffffffa0726485>] ? test_range_bit+0xe5/0x130 [btrfs]
[17047.653927]  [<ffffffffa070e2fc>] run_delalloc_range+0x3bc/0x3f0 [btrfs]
[17047.653935]  [<ffffffffa07266b7>] ?
find_lock_delalloc_range.constprop.42+0x1e7/0x210 [btrfs]
[17047.653944]  [<ffffffffa07267e5>]
writepage_delalloc.isra.34+0x105/0x170 [btrfs]
[17047.653952]  [<ffffffffa07285f5>] __extent_writepage+0xf5/0x3d0 [btrfs]
[17047.653962]  [<ffffffffa0728bda>]
extent_write_cache_pages.isra.31.constprop.47+0x30a/0x400 [btrfs]
[17047.653965]  [<ffffffff81025c09>] ? sched_clock+0x9/0x10
[17047.653967]  [<ffffffff810e5e8c>] ? local_clock+0x1c/0x20
[17047.653977]  [<ffffffffa0729e8c>] extent_writepages+0x5c/0x90 [btrfs]
[17047.653987]  [<ffffffffa070acc0>] ? btrfs_real_readdir+0x590/0x590 [btrfs]
[17047.653994]  [<ffffffffa0708918>] btrfs_writepages+0x28/0x30 [btrfs]
[17047.653996]  [<ffffffff811efc21>] do_writepages+0x21/0x30
[17047.653998]  [<ffffffff811e08e6>] __filemap_fdatawrite_range+0xc6/0x100
[17047.654000]  [<ffffffff811e09f3>] filemap_fdatawrite_range+0x13/0x20
[17047.654008]  [<ffffffffa071cd90>] btrfs_fdatawrite_range+0x20/0x50 [btrfs]
[17047.654016]  [<ffffffffa071cdd9>] start_ordered_ops+0x19/0x30 [btrfs]
[17047.654023]  [<ffffffffa071ce73>] btrfs_sync_file+0x83/0x420 [btrfs]
[17047.654026]  [<ffffffff812a894b>] vfs_fsync_range+0x4b/0xb0
[17047.654029]  [<ffffffff8128ee4a>] ? __fget_light+0x2a/0x90
[17047.654031]  [<ffffffff812a8a0d>] do_fsync+0x3d/0x70
[17047.654032]  [<ffffffff812a8cf3>] SyS_fdatasync+0x13/0x20
[17047.654034]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
[17047.654035] 1 lock held by BrowserBlocking/3499:
[17047.654035]  #0:  (sb_internal#2){.+.+..}, at: [<ffffffff81270ad9>]
__sb_start_write+0xc9/0x110
[17047.654040] INFO: task BrowserBlocking:3500 blocked for more than
120 seconds.
[17047.654057]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.654071] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.654089] BrowserBlocking D ffff8807fe9d7a18 10840  3500   3267 0x00000000
[17047.654092]  ffff88074fc03ac8 0000000000000086 ffffffff811067cd
ffff880700000000
[17047.654094]  ffff8807fa364000 ffff880767f40000 ffff88074fc04000
ffff880003753e90
[17047.654096]  ffff880767f40000 ffff880767f40000 ffff88074fc03b08
ffff88074fc03ae0
[17047.654097] Call Trace:
[17047.654099]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.654101]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.654108]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
[17047.654109]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
[17047.654113]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
[17047.654117]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
[17047.654123]  [<ffffffffa06fa85e>] btrfs_lookup_inode+0x3e/0xc0 [btrfs]
[17047.654129]  [<ffffffffa0713059>] btrfs_iget+0xf9/0x6a0 [btrfs]
[17047.654133]  [<ffffffffa06e1869>] ? btrfs_search_forward+0x2d9/0x350 [btrfs]
[17047.654140]  [<ffffffffa0749d14>] btrfs_log_inode_parent+0xbc4/0xeb0 [btrfs]
[17047.654147]  [<ffffffffa074aff2>] btrfs_log_dentry_safe+0x62/0x80 [btrfs]
[17047.654153]  [<ffffffffa071d0ee>] btrfs_sync_file+0x2fe/0x420 [btrfs]
[17047.654154]  [<ffffffff812a894b>] vfs_fsync_range+0x4b/0xb0
[17047.654155]  [<ffffffff8128ee4a>] ? __fget_light+0x2a/0x90
[17047.654156]  [<ffffffff812a8a0d>] do_fsync+0x3d/0x70
[17047.654157]  [<ffffffff812a8cf3>] SyS_fdatasync+0x13/0x20
[17047.654158]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
[17047.654160] 2 locks held by BrowserBlocking/3500:
[17047.654160]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
[<ffffffffa071cf3f>] btrfs_sync_file+0x14f/0x420 [btrfs]
[17047.654167]  #1:  (sb_internal#2){.+.+..}, at: [<ffffffff81270ad9>]
__sb_start_write+0xc9/0x110
[17047.654170] INFO: task Chrome_DBThread:3501 blocked for more than
120 seconds.
[17047.654187]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
[17047.654201] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[17047.654218] Chrome_DBThread D ffff8807fe3d7a18 10536  3501   3267 0x00000000
[17047.654221]  ffff880759bf3cf0 0000000000000092 ffffffff811067cd
ffff880700000000
[17047.654222]  ffff8807fa344000 ffff880767f68000 ffff880759bf4000
ffff880037c60800
[17047.654224]  0000000000000001 0000000000000000 ffff880037c60780
ffff880759bf3d08
[17047.654226] Call Trace:
[17047.654227]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
[17047.654228]  [<ffffffff818605ba>] schedule+0x3a/0x90
[17047.654235]  [<ffffffffa0722434>]
btrfs_start_ordered_extent+0x164/0x1f0 [btrfs]
[17047.654237]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
[17047.654245]  [<ffffffffa0722939>] btrfs_wait_ordered_range+0xa9/0x110 [btrfs]
[17047.654252]  [<ffffffffa0711c23>] btrfs_truncate+0x43/0x2c0 [btrfs]
[17047.654260]  [<ffffffffa0712584>] btrfs_setattr+0x1f4/0x370 [btrfs]
[17047.654261]  [<ffffffff8128e095>] notify_change+0x245/0x360
[17047.654264]  [<ffffffff8126b5b7>] do_truncate+0x77/0xc0
[17047.654266]  [<ffffffff8126b942>] do_sys_ftruncate.constprop.13+0x112/0x160
[17047.654267]  [<ffffffff8126b9ce>] SyS_ftruncate+0xe/0x10
[17047.654269]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
[17047.654270] 2 locks held by Chrome_DBThread/3501:
[17047.654271]  #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff81270ad9>]
__sb_start_write+0xc9/0x110
[17047.654274]  #1:  (&sb->s_type->i_mutex_key#19){+.+.+.}, at:
[<ffffffff8126b5a9>] do_truncate+0x69/0xc0



--
Best Regards,
Mike Gavrilov.

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Liu Bo]

On Wed, Feb 03, 2016 at 01:20:22AM +0500, Михаил Гаврилов wrote:
> Hi all! I have problem with hanging btrfs file system.

It's not clear that who held the lock, any luck to find clues in
sysrq+w?

Thanks,

-liubo
> 
> [17047.652816] INFO: task btrfs-cleaner:770 blocked for more than 120 seconds.
> [17047.652837]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.652853] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.652875] btrfs-cleaner   D ffff8807fe3d7a18 10264   770      2 0x00000080
> [17047.652880]  ffff8807e50f7a50 0000000000000092 ffffffff811067cd
> ffff880700000000
> [17047.652882]  ffff8807fa344000 ffff8807e68ec000 ffff8807e50f8000
> ffff880003753e90
> [17047.652884]  ffff8807e68ec000 ffff8807e68ec000 ffff8807e50f7a90
> ffff8807e50f7a68
> [17047.652886] Call Trace:
> [17047.652891]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.652894]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.652909]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
> [17047.652912]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
> [17047.652918]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
> [17047.652923]  [<ffffffffa06e15e9>] btrfs_search_forward+0x59/0x350 [btrfs]
> [17047.652927]  [<ffffffff81247cb1>] ? kmem_cache_alloc+0x281/0x310
> [17047.652931]  [<ffffffffa06d92aa>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
> [17047.652940]  [<ffffffffa073c946>]
> find_new_extents.constprop.43+0xa6/0x2d0 [btrfs]
> [17047.652942]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
> [17047.652943]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.652952]  [<ffffffffa0740418>] btrfs_defrag_file+0x8d8/0xd60 [btrfs]
> [17047.652955]  [<ffffffff81270ad9>] ? __sb_start_write+0xc9/0x110
> [17047.652963]  [<ffffffffa07197b2>] btrfs_run_defrag_inodes+0x242/0x390 [btrfs]
> [17047.652971]  [<ffffffffa0719660>] ?
> btrfs_run_defrag_inodes+0xf0/0x390 [btrfs]
> [17047.652978]  [<ffffffffa06fce1b>] cleaner_kthread+0xcb/0x210 [btrfs]
> [17047.652984]  [<ffffffffa06fcd50>] ?
> btree_read_extent_buffer_pages.constprop.54+0x110/0x110 [btrfs]
> [17047.652986]  [<ffffffff810d1351>] kthread+0x101/0x120
> [17047.652987]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
> [17047.652989]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
> [17047.652991]  [<ffffffff818673af>] ret_from_fork+0x3f/0x70
> [17047.652992]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
> [17047.652993] 1 lock held by btrfs-cleaner/770:
> [17047.652994]  #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff81270ad9>]
> __sb_start_write+0xc9/0x110
> [17047.652999] INFO: task btrfs-transacti:771 blocked for more than 120 seconds.
> [17047.653019]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.653032] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.653053] btrfs-transacti D ffff8807fe1d7a18  9912   771      2 0x00000080
> [17047.653056]  ffff8807e50fbb20 0000000000000096 ffffffff811067cd
> ffff880700000000
> [17047.653058]  ffff8807fa33c000 ffff8807f7140000 ffff8807e50fc000
> ffff880003753e90
> [17047.653060]  ffff8807f7140000 ffff8807f7140000 ffff8807e50fbb60
> ffff8807e50fbb38
> [17047.653062] Call Trace:
> [17047.653063]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.653065]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.653074]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
> [17047.653076]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
> [17047.653081]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
> [17047.653086]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
> [17047.653092]  [<ffffffffa06e04c1>] btrfs_insert_empty_items+0x71/0xc0 [btrfs]
> [17047.653101]  [<ffffffffa075e9e5>]
> __btrfs_run_delayed_items+0x135/0x600 [btrfs]
> [17047.653104]  [<ffffffff810e5e8c>] ? local_clock+0x1c/0x20
> [17047.653113]  [<ffffffffa075f4f3>] btrfs_run_delayed_items+0x13/0x20 [btrfs]
> [17047.653120]  [<ffffffffa0705fc0>]
> btrfs_commit_transaction+0x2f0/0xbd0 [btrfs]
> [17047.653127]  [<ffffffffa0700f48>] transaction_kthread+0x208/0x270 [btrfs]
> [17047.653134]  [<ffffffffa0700d40>] ?
> btrfs_cleanup_transaction+0x610/0x610 [btrfs]
> [17047.653135]  [<ffffffff810d1351>] kthread+0x101/0x120
> [17047.653137]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
> [17047.653138]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
> [17047.653140]  [<ffffffff818673af>] ret_from_fork+0x3f/0x70
> [17047.653141]  [<ffffffff810d1250>] ? kthread_create_on_node+0x250/0x250
> [17047.653142] 2 locks held by btrfs-transacti/771:
> [17047.653143]  #0:  (&fs_info->transaction_kthread_mutex){+.+...},
> at: [<ffffffffa0700db2>] transaction_kthread+0x72/0x270 [btrfs]
> [17047.653151]  #1:  (&delayed_node->mutex){+.+.-.}, at:
> [<ffffffffa075e9ac>] __btrfs_run_delayed_items+0xfc/0x600 [btrfs]
> [17047.653190] INFO: task systemd:2059 blocked for more than 120 seconds.
> [17047.653209]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.653225] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.653246] systemd         D ffff8807fe5d7a18 12696  2059      1 0x00000000
> [17047.653250]  ffff8807f6d9f9b8 0000000000000082 ffffffff81f62300
> 0000000000000004
> [17047.653252]  ffff880725b84000 ffff8807c0afc000 ffff8807f6da0000
> ffff880003753e90
> [17047.653253]  ffff8807c0afc000 ffff8807c0afc000 ffff8807f6d9f9f8
> ffff8807f6d9f9d0
> [17047.653255] Call Trace:
> [17047.653257]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.653266]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
> [17047.653268]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
> [17047.653273]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
> [17047.653278]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
> [17047.653286]  [<ffffffffa0782058>] ? btrfs_crc32c+0x68/0x90 [btrfs]
> [17047.653292]  [<ffffffffa06f7b68>] btrfs_lookup_dir_item+0x78/0xc0 [btrfs]
> [17047.653300]  [<ffffffffa0713ab6>] btrfs_lookup_dentry+0xb6/0x550 [btrfs]
> [17047.653302]  [<ffffffff81866597>] ? _raw_spin_unlock+0x27/0x40
> [17047.653309]  [<ffffffffa0713f62>] btrfs_lookup+0x12/0x40 [btrfs]
> [17047.653311]  [<ffffffff81277dcd>] lookup_real+0x1d/0x60
> [17047.653312]  [<ffffffff81278d72>] __lookup_hash+0x42/0x60
> [17047.653314]  [<ffffffff8127c2ef>] walk_component+0x1df/0x2a0
> [17047.653315]  [<ffffffff8127c540>] link_path_walk+0x190/0x5a0
> [17047.653317]  [<ffffffff8127bb57>] ? path_init+0x557/0x800
> [17047.653318]  [<ffffffff8127bb0f>] ? path_init+0x50f/0x800
> [17047.653319]  [<ffffffff8127cb8b>] path_openat+0xab/0x1260
> [17047.653321]  [<ffffffff81025c09>] ? sched_clock+0x9/0x10
> [17047.653323]  [<ffffffff810e5e8c>] ? local_clock+0x1c/0x20
> [17047.653325]  [<ffffffff8127f1a1>] do_filp_open+0x91/0x100
> [17047.653326]  [<ffffffff81866597>] ? _raw_spin_unlock+0x27/0x40
> [17047.653328]  [<ffffffff8128f56f>] ? __alloc_fd+0xaf/0x180
> [17047.653330]  [<ffffffff8126cb9a>] do_sys_open+0x13a/0x230
> [17047.653332]  [<ffffffff8126ccae>] SyS_open+0x1e/0x20
> [17047.653333]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
> [17047.653335] 1 lock held by systemd/2059:
> [17047.653335]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
> [<ffffffff8127c2e0>] walk_component+0x1d0/0x2a0
> [17047.653345] INFO: task gnome-shell:2455 blocked for more than 120 seconds.
> [17047.653362]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.653377] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.653398] gnome-shell     D ffff8807fe3d7a18 11064  2455   2276 0x00000000
> [17047.653401]  ffff8807b48cfb70 0000000000000096 ffff8807b5a64928
> ffff880700000000
> [17047.653403]  ffff8807fa344000 ffff8807b5a64000 ffff8807b48d0000
> 0000000000000246
> [17047.653405]  ffff8807e5fa0cd0 ffff8807b5a64000 00000000ffffffff
> ffff8807b48cfb88
> [17047.653407] Call Trace:
> [17047.653408]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.653410]  [<ffffffff81860995>] schedule_preempt_disabled+0x15/0x20
> [17047.653412]  [<ffffffff81863390>] mutex_lock_nested+0x190/0x400
> [17047.653413]  [<ffffffff8127c2e0>] ? walk_component+0x1d0/0x2a0
> [17047.653414]  [<ffffffff8127c2e0>] ? walk_component+0x1d0/0x2a0
> [17047.653416]  [<ffffffff8127c2e0>] walk_component+0x1d0/0x2a0
> [17047.653417]  [<ffffffff8127c540>] link_path_walk+0x190/0x5a0
> [17047.653419]  [<ffffffff8127bb57>] ? path_init+0x557/0x800
> [17047.653420]  [<ffffffff8127bb0f>] ? path_init+0x50f/0x800
> [17047.653421]  [<ffffffff8127ca4c>] path_lookupat+0x7c/0x110
> [17047.653422]  [<ffffffff8127e5a1>] filename_lookup+0xb1/0x180
> [17047.653426]  [<ffffffff811258bd>] ? rcu_read_lock_sched_held+0x6d/0x80
> [17047.653428]  [<ffffffff81247cb1>] ? kmem_cache_alloc+0x281/0x310
> [17047.653429]  [<ffffffff8127e1a6>] ? getname_flags+0x56/0x1f0
> [17047.653432]  [<ffffffff81025c09>] ? sched_clock+0x9/0x10
> [17047.653433]  [<ffffffff8127e746>] user_path_at_empty+0x36/0x40
> [17047.653435]  [<ffffffff81272aa6>] vfs_fstatat+0x66/0xc0
> [17047.653436]  [<ffffffff8127303e>] SYSC_newstat+0x2e/0x60
> [17047.653439]  [<ffffffff8106e6a8>] ? __do_page_fault+0x1e8/0x470
> [17047.653441]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
> [17047.653443]  [<ffffffff81003044>] ? lockdep_sys_exit_thunk+0x12/0x14
> [17047.653445]  [<ffffffff812731ce>] SyS_newstat+0xe/0x10
> [17047.653446]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
> [17047.653448] 1 lock held by gnome-shell/2455:
> [17047.653448]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
> [<ffffffff8127c2e0>] walk_component+0x1d0/0x2a0
> [17047.653471] INFO: task htop:3020 blocked for more than 120 seconds.
> [17047.653488]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.653502] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.653523] htop            D ffff8807fddd7a18 11800  3020   2972 0x00000000
> [17047.653527]  ffff88078866bcb8 0000000000000082 ffffffffffffffff
> ffff880700000000
> [17047.653529]  ffffffff81e12500 ffff88078b5dc000 ffff88078866c000
> ffff8807c0b66eb0
> [17047.653530]  ffffffffffffffff ffff8807c0b66ec8 ffff8807c0b66e00
> ffff88078866bcd0
> [17047.653532] Call Trace:
> [17047.653534]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.653536]  [<ffffffff81864aff>] rwsem_down_read_failed+0xcf/0x140
> [17047.653539]  [<ffffffff8142af54>] call_rwsem_down_read_failed+0x14/0x30
> [17047.653541]  [<ffffffff81864363>] ? down_read+0x83/0xa0
> [17047.653544]  [<ffffffff812ec931>] ? proc_pid_cmdline_read+0xb1/0x560
> [17047.653546]  [<ffffffff812ec931>] proc_pid_cmdline_read+0xb1/0x560
> [17047.653547]  [<ffffffff81106739>] ? trace_hardirqs_on_caller+0x129/0x1b0
> [17047.653549]  [<ffffffff8126cf57>] __vfs_read+0x37/0x100
> [17047.653551]  [<ffffffff813936b3>] ? security_file_permission+0xa3/0xc0
> [17047.653553]  [<ffffffff8126da66>] vfs_read+0x86/0x130
> [17047.653554]  [<ffffffff8126e7e8>] SyS_read+0x58/0xd0
> [17047.653555]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
> [17047.653557] 1 lock held by htop/3020:
> [17047.653557]  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff812ec931>]
> proc_pid_cmdline_read+0xb1/0x560
> [17047.653563] INFO: task SQLyog.exe:3780 blocked for more than 120 seconds.
> [17047.653579]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.653595] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.653616] SQLyog.exe      D ffff8807fe1d7a18 11192  3780   3069 0x00000000
> [17047.653619]  ffff8807384f7c90 0000000000000092 ffffffff811067cd
> ffff880700000000
> [17047.653621]  ffff8807fa33c000 ffff88073854c000 ffff8807384f8000
> ffff880003753e90
> [17047.653623]  ffff88073854c000 ffff88073854c000 ffff8807384f7cd0
> ffff8807384f7ca8
> [17047.653624] Call Trace:
> [17047.653626]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.653628]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.653637]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
> [17047.653639]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
> [17047.653644]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
> [17047.653649]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
> [17047.653650]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.653652]  [<ffffffff81863ebe>] ? mutex_unlock+0xe/0x10
> [17047.653659]  [<ffffffffa070a819>] btrfs_real_readdir+0xe9/0x590 [btrfs]
> [17047.653662]  [<ffffffff81282d37>] iterate_dir+0x97/0x130
> [17047.653663]  [<ffffffff8128328a>] SyS_getdents+0x9a/0x130
> [17047.653664]  [<ffffffff81282ed0>] ? fillonedir+0x100/0x100
> [17047.653666]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
> [17047.653667] 1 lock held by SQLyog.exe/3780:
> [17047.653668]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
> [<ffffffff81282d01>] iterate_dir+0x61/0x130
> [17047.653677] INFO: task chrome:3329 blocked for more than 120 seconds.
> [17047.653694]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.653710] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.653728] chrome          D ffff8807fe3d7a18 11432  3329   3267 0x00000000
> [17047.653732]  ffff88076ea27dc8 0000000000000086 ffffffffffffffff
> ffff880700000000
> [17047.653734]  ffff8807fa344000 ffff8807706f4000 ffff88076ea28000
> ffff8807f4ab00b0
> [17047.653735]  ffffffffffffffff ffff8807f4ab00c8 ffff8807706f4000
> ffff88076ea27de0
> [17047.653737] Call Trace:
> [17047.653739]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.653741]  [<ffffffff81864aff>] rwsem_down_read_failed+0xcf/0x140
> [17047.653743]  [<ffffffff8142af54>] call_rwsem_down_read_failed+0x14/0x30
> [17047.653745]  [<ffffffff81864363>] ? down_read+0x83/0xa0
> [17047.653746]  [<ffffffff8106e89c>] ? __do_page_fault+0x3dc/0x470
> [17047.653748]  [<ffffffff8106e89c>] __do_page_fault+0x3dc/0x470
> [17047.653749]  [<ffffffff8126daf7>] ? vfs_read+0x117/0x130
> [17047.653751]  [<ffffffff8106e95f>] do_page_fault+0x2f/0x80
> [17047.653753]  [<ffffffff81869478>] page_fault+0x28/0x30
> [17047.653754] 1 lock held by chrome/3329:
> [17047.653755]  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8106e89c>]
> __do_page_fault+0x3dc/0x470
> [17047.653774] INFO: task BrowserBlocking:3499 blocked for more than
> 120 seconds.
> [17047.653792]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.653807] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.653828] BrowserBlocking D ffff8807fddd7a18 10840  3499   3267 0x00000000
> [17047.653832]  ffff880767137658 0000000000000086 ffffffff811067cd
> ffff880700000000
> [17047.653834]  ffffffff81e12500 ffff8807c0ac0000 ffff880767138000
> ffff880003753e90
> [17047.653835]  ffff8807c0ac0000 ffff8807c0ac0000 ffff880767137698
> ffff880767137670
> [17047.653837] Call Trace:
> [17047.653839]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.653841]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.653850]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
> [17047.653851]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
> [17047.653856]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
> [17047.653861]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
> [17047.653868]  [<ffffffffa06f8959>] btrfs_lookup_file_extent+0x49/0x60 [btrfs]
> [17047.653876]  [<ffffffffa071a935>] __btrfs_drop_extents+0x185/0xd90 [btrfs]
> [17047.653878]  [<ffffffff8112515d>] ? debug_lockdep_rcu_enabled+0x1d/0x20
> [17047.653885]  [<ffffffffa0706931>] ? start_transaction+0x91/0x610 [btrfs]
> [17047.653893]  [<ffffffffa070cac6>] cow_file_range_inline+0x1b6/0x690 [btrfs]
> [17047.653901]  [<ffffffffa0724c62>] ? __set_extent_bit+0x472/0x570 [btrfs]
> [17047.653909]  [<ffffffffa070d2ee>] cow_file_range+0x34e/0x440 [btrfs]
> [17047.653911]  [<ffffffff81866597>] ? _raw_spin_unlock+0x27/0x40
> [17047.653919]  [<ffffffffa0726485>] ? test_range_bit+0xe5/0x130 [btrfs]
> [17047.653927]  [<ffffffffa070e2fc>] run_delalloc_range+0x3bc/0x3f0 [btrfs]
> [17047.653935]  [<ffffffffa07266b7>] ?
> find_lock_delalloc_range.constprop.42+0x1e7/0x210 [btrfs]
> [17047.653944]  [<ffffffffa07267e5>]
> writepage_delalloc.isra.34+0x105/0x170 [btrfs]
> [17047.653952]  [<ffffffffa07285f5>] __extent_writepage+0xf5/0x3d0 [btrfs]
> [17047.653962]  [<ffffffffa0728bda>]
> extent_write_cache_pages.isra.31.constprop.47+0x30a/0x400 [btrfs]
> [17047.653965]  [<ffffffff81025c09>] ? sched_clock+0x9/0x10
> [17047.653967]  [<ffffffff810e5e8c>] ? local_clock+0x1c/0x20
> [17047.653977]  [<ffffffffa0729e8c>] extent_writepages+0x5c/0x90 [btrfs]
> [17047.653987]  [<ffffffffa070acc0>] ? btrfs_real_readdir+0x590/0x590 [btrfs]
> [17047.653994]  [<ffffffffa0708918>] btrfs_writepages+0x28/0x30 [btrfs]
> [17047.653996]  [<ffffffff811efc21>] do_writepages+0x21/0x30
> [17047.653998]  [<ffffffff811e08e6>] __filemap_fdatawrite_range+0xc6/0x100
> [17047.654000]  [<ffffffff811e09f3>] filemap_fdatawrite_range+0x13/0x20
> [17047.654008]  [<ffffffffa071cd90>] btrfs_fdatawrite_range+0x20/0x50 [btrfs]
> [17047.654016]  [<ffffffffa071cdd9>] start_ordered_ops+0x19/0x30 [btrfs]
> [17047.654023]  [<ffffffffa071ce73>] btrfs_sync_file+0x83/0x420 [btrfs]
> [17047.654026]  [<ffffffff812a894b>] vfs_fsync_range+0x4b/0xb0
> [17047.654029]  [<ffffffff8128ee4a>] ? __fget_light+0x2a/0x90
> [17047.654031]  [<ffffffff812a8a0d>] do_fsync+0x3d/0x70
> [17047.654032]  [<ffffffff812a8cf3>] SyS_fdatasync+0x13/0x20
> [17047.654034]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
> [17047.654035] 1 lock held by BrowserBlocking/3499:
> [17047.654035]  #0:  (sb_internal#2){.+.+..}, at: [<ffffffff81270ad9>]
> __sb_start_write+0xc9/0x110
> [17047.654040] INFO: task BrowserBlocking:3500 blocked for more than
> 120 seconds.
> [17047.654057]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.654071] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.654089] BrowserBlocking D ffff8807fe9d7a18 10840  3500   3267 0x00000000
> [17047.654092]  ffff88074fc03ac8 0000000000000086 ffffffff811067cd
> ffff880700000000
> [17047.654094]  ffff8807fa364000 ffff880767f40000 ffff88074fc04000
> ffff880003753e90
> [17047.654096]  ffff880767f40000 ffff880767f40000 ffff88074fc03b08
> ffff88074fc03ae0
> [17047.654097] Call Trace:
> [17047.654099]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.654101]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.654108]  [<ffffffffa0743ad2>] btrfs_tree_read_lock+0x102/0x160 [btrfs]
> [17047.654109]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
> [17047.654113]  [<ffffffffa06d96d4>] btrfs_read_lock_root_node+0x34/0x50 [btrfs]
> [17047.654117]  [<ffffffffa06de8ff>] btrfs_search_slot+0x73f/0x9f0 [btrfs]
> [17047.654123]  [<ffffffffa06fa85e>] btrfs_lookup_inode+0x3e/0xc0 [btrfs]
> [17047.654129]  [<ffffffffa0713059>] btrfs_iget+0xf9/0x6a0 [btrfs]
> [17047.654133]  [<ffffffffa06e1869>] ? btrfs_search_forward+0x2d9/0x350 [btrfs]
> [17047.654140]  [<ffffffffa0749d14>] btrfs_log_inode_parent+0xbc4/0xeb0 [btrfs]
> [17047.654147]  [<ffffffffa074aff2>] btrfs_log_dentry_safe+0x62/0x80 [btrfs]
> [17047.654153]  [<ffffffffa071d0ee>] btrfs_sync_file+0x2fe/0x420 [btrfs]
> [17047.654154]  [<ffffffff812a894b>] vfs_fsync_range+0x4b/0xb0
> [17047.654155]  [<ffffffff8128ee4a>] ? __fget_light+0x2a/0x90
> [17047.654156]  [<ffffffff812a8a0d>] do_fsync+0x3d/0x70
> [17047.654157]  [<ffffffff812a8cf3>] SyS_fdatasync+0x13/0x20
> [17047.654158]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
> [17047.654160] 2 locks held by BrowserBlocking/3500:
> [17047.654160]  #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at:
> [<ffffffffa071cf3f>] btrfs_sync_file+0x14f/0x420 [btrfs]
> [17047.654167]  #1:  (sb_internal#2){.+.+..}, at: [<ffffffff81270ad9>]
> __sb_start_write+0xc9/0x110
> [17047.654170] INFO: task Chrome_DBThread:3501 blocked for more than
> 120 seconds.
> [17047.654187]       Not tainted 4.3.5-300.fc23.x86_64+debug #1
> [17047.654201] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [17047.654218] Chrome_DBThread D ffff8807fe3d7a18 10536  3501   3267 0x00000000
> [17047.654221]  ffff880759bf3cf0 0000000000000092 ffffffff811067cd
> ffff880700000000
> [17047.654222]  ffff8807fa344000 ffff880767f68000 ffff880759bf4000
> ffff880037c60800
> [17047.654224]  0000000000000001 0000000000000000 ffff880037c60780
> ffff880759bf3d08
> [17047.654226] Call Trace:
> [17047.654227]  [<ffffffff811067cd>] ? trace_hardirqs_on+0xd/0x10
> [17047.654228]  [<ffffffff818605ba>] schedule+0x3a/0x90
> [17047.654235]  [<ffffffffa0722434>]
> btrfs_start_ordered_extent+0x164/0x1f0 [btrfs]
> [17047.654237]  [<ffffffff810fa7b0>] ? wake_atomic_t_function+0x70/0x70
> [17047.654245]  [<ffffffffa0722939>] btrfs_wait_ordered_range+0xa9/0x110 [btrfs]
> [17047.654252]  [<ffffffffa0711c23>] btrfs_truncate+0x43/0x2c0 [btrfs]
> [17047.654260]  [<ffffffffa0712584>] btrfs_setattr+0x1f4/0x370 [btrfs]
> [17047.654261]  [<ffffffff8128e095>] notify_change+0x245/0x360
> [17047.654264]  [<ffffffff8126b5b7>] do_truncate+0x77/0xc0
> [17047.654266]  [<ffffffff8126b942>] do_sys_ftruncate.constprop.13+0x112/0x160
> [17047.654267]  [<ffffffff8126b9ce>] SyS_ftruncate+0xe/0x10
> [17047.654269]  [<ffffffff81867032>] entry_SYSCALL_64_fastpath+0x12/0x76
> [17047.654270] 2 locks held by Chrome_DBThread/3501:
> [17047.654271]  #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff81270ad9>]
> __sb_start_write+0xc9/0x110
> [17047.654274]  #1:  (&sb->s_type->i_mutex_key#19){+.+.+.}, at:
> [<ffffffff8126b5a9>] do_truncate+0x69/0xc0
> 
> 
> 
> --
> Best Regards,
> Mike Gavrilov.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Chris Murphy]

On Tue, Feb 2, 2016 at 1:20 PM, Михаил Гаврилов
<mikhail.v.gavrilov@gmail.com> wrote:
> Hi all! I have problem with hanging btrfs file system.


Can you list the workload at the time, and also the mount options? To
do sysrq+w as Liu Bo asks for, do this:

echo 1 > /proc/sys/kernel/sysrq
echo w > /proc/sysrq-trigger

And then 'journalctl -k > kernel-sysrqw_btrfscleaner770blocked.txt'
See if that will attach to the list, and if it's too big and bounces,
put it up somewhere and post the URL.

-- 
Chris Murphy

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Chris Murphy]

On Tue, Feb 2, 2016 at 8:52 PM, Михаил Гаврилов
<mikhail.v.gavrilov@gmail.com> wrote:
> 2016-02-03 7:45 GMT+05:00 Chris Murphy <lists@colorremedies.com>:
>> journalctl -k > kernel-sysrqw_btrfscleaner770blocked.txt
>
>
> This I can do now or after next hang?

The sysrq+w should happen when the hang is happening. This dumps
hanged task info to kernel messages (dmesg) but can sometimes be
bigger than the default buffer, but all of it will be in journalctl -k
(as well as all kernel messages since boot which can sometimes be
useful).



-- 
Chris Murphy

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Chris Murphy]

Mike: From your attachment, looks like you rebooted. So do this:

echo 1 > /proc/sys/kernel/sysrq
Reproduce the problem where you get blocked task messages in dmesg
echo w > /proc/sysrq-trigger
journalctl -k > kernel-sysrqw-btrfscleaner770blocked-2.txt


Make sure you use the same mount options. Looks like you're using
autodefrag, and inode_cache. Are there others? And can you say what
the workload is? Especially because inode_cache is not a default mount
option and isn't recommended except for certain workloads, but still I
think it shouldn't hang. But that's a question for Liu Bo.


Chris Murphy

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Михаил Гаврилов]

2016-02-03 9:48 GMT+05:00 Chris Murphy <lists@colorremedies.com>:
> Mike: From your attachment, looks like you rebooted. So do this:
>
> echo 1 > /proc/sys/kernel/sysrq
> Reproduce the problem where you get blocked task messages in dmesg
> echo w > /proc/sysrq-trigger
> journalctl -k > kernel-sysrqw-btrfscleaner770blocked-2.txt
>
>
> Make sure you use the same mount options. Looks like you're using
> autodefrag, and inode_cache. Are there others? And can you say what
> the workload is? Especially because inode_cache is not a default mount
> option and isn't recommended except for certain workloads, but still I
> think it shouldn't hang. But that's a question for Liu Bo.
>
>
> Chris Murphy

Thanks Chris for clarification.
I am not have exactly algorithm for reproducing this.
But it happens with my btrfs partition again.

*Hang occured here*
echo 1 > /proc/sys/kernel/sysrq
Reproduce the problem where you get blocked task messages in dmesg
echo w > /proc/sysrq-trigger
journalctl -k > kernel-sysrqw-btrfscleaner770blocked-2.txt

Here full log: http://btrfs.sy24.ru/kernel-sysrqw-btrfscleaner770blocked-2.txt

I am so sorry if this log is useless.
If "sysrq" is needed enabled before hang then I need set this
permanently because as I said I not having exactly reproducing this.

My mount options:
UUID=82df2d84-bf54-46cb-84ba-c88e93677948 /home btrfs
subvolid=5,autodefrag,noatime,space_cache,inode_cache 0 0


--
Best Regards,
Mike Gavrilov.

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Chris Murphy]

On Wed, Feb 10, 2016 at 1:39 PM, Михаил Гаврилов
<mikhail.v.gavrilov@gmail.com> wrote:


>
> Here full log: http://btrfs.sy24.ru/kernel-sysrqw-btrfscleaner770blocked-2.txt
>
> I am so sorry if this log is useless.

Looks good to me. The blocked task happens out of no where with
nothing reported for almost an hour before the blocking. And I see the
sysrq: SysRq : Show Blocked State was issued and lots of information
is in the file.

> If "sysrq" is needed enabled before hang then I need set this
> permanently because as I said I not having exactly reproducing this.

echo 1 > /proc/sys/kernel/sysrq can happen anytime, it just enables
sysrq triggering functions which on Fedora kernels is not enabled by
default. The main thing is that the echo w to the sysrq trigger needs
to happen at the time of the problem to show the state. You did that.
Let's see what Liu Bo has to say about it.


-- 
Chris Murphy

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Liu Bo]

On Wed, Feb 10, 2016 at 02:23:00PM -0700, Chris Murphy wrote:
> On Wed, Feb 10, 2016 at 1:39 PM, Михаил Гаврилов
> <mikhail.v.gavrilov@gmail.com> wrote:
> 
> 
> >
> > Here full log: http://btrfs.sy24.ru/kernel-sysrqw-btrfscleaner770blocked-2.txt
> >
> > I am so sorry if this log is useless.
> 
> Looks good to me. The blocked task happens out of no where with
> nothing reported for almost an hour before the blocking. And I see the
> sysrq: SysRq : Show Blocked State was issued and lots of information
> is in the file.
> 
> > If "sysrq" is needed enabled before hang then I need set this
> > permanently because as I said I not having exactly reproducing this.
> 
> echo 1 > /proc/sys/kernel/sysrq can happen anytime, it just enables
> sysrq triggering functions which on Fedora kernels is not enabled by
> default. The main thing is that the echo w to the sysrq trigger needs
> to happen at the time of the problem to show the state. You did that.
> Let's see what Liu Bo has to say about it.

Really appreciate for collecting these, it should be helpful.

Unfortunately I still could not figure out who's holding fs tree's root WRITE_LOCK so that others are blocked.

A possible bug in log code (the follwing patch addressed it),

- log_new_dir_dentries() is holding log tree's leaf READ_LOCK and may try
  to get fs tree's READ_LOCK via btrfs_iget() -> btrfs_lookup().
  (This is shown in the backtrac)

- btrfs_log_inode() can call btrfs_search_forward() to get fs tree's
  leaf READ_LOCK and then call copy_items() -> btrfs_insert_empty_items()
  to acquire WRITE_LOCK of log tree's leaf and leaf's parent.  
  (In the backtrace, this is blocked by item 1 because log_new_dir_dentries is
  holding a log tree leaf's READ_LOCK() which happens to be sibling to
  the leaf that btrfs_insert_empty_items() is accessing, when doing
  split_leaf() it needs to get the sibling's WRITE_LOCK(). )

Thanks,

-liubo

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 323e12c..4a64fdd 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -4956,6 +4956,7 @@ process_leaf:
 			if (di_key.type == BTRFS_ROOT_ITEM_KEY)
 				continue;
 
+			btrfs_release_path(path);
 			di_inode = btrfs_iget(root->fs_info->sb, &di_key,
 					      root, NULL);
 			if (IS_ERR(di_inode)) {
@@ -4971,7 +4972,6 @@ process_leaf:
 			ctx->log_new_dentries = false;
 			if (type == BTRFS_FT_DIR)
 				log_mode = LOG_INODE_ALL;
-			btrfs_release_path(path);
 			ret = btrfs_log_inode(trans, root, di_inode,
 					      log_mode, 0, LLONG_MAX, ctx);
 			iput(di_inode);

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Михаил Гаврилов]

Thanks guys, I appreciate your's work.
In which kernel this patch would landed?

--
Best Regards,
Mike Gavrilov.


2016-02-12 0:18 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
>
> Really appreciate for collecting these, it should be helpful.
>
> Unfortunately I still could not figure out who's holding fs tree's root WRITE_LOCK so that others are blocked.
>
> A possible bug in log code (the follwing patch addressed it),
>
> - log_new_dir_dentries() is holding log tree's leaf READ_LOCK and may try
>   to get fs tree's READ_LOCK via btrfs_iget() -> btrfs_lookup().
>   (This is shown in the backtrac)
>
> - btrfs_log_inode() can call btrfs_search_forward() to get fs tree's
>   leaf READ_LOCK and then call copy_items() -> btrfs_insert_empty_items()
>   to acquire WRITE_LOCK of log tree's leaf and leaf's parent.
>   (In the backtrace, this is blocked by item 1 because log_new_dir_dentries is
>   holding a log tree leaf's READ_LOCK() which happens to be sibling to
>   the leaf that btrfs_insert_empty_items() is accessing, when doing
>   split_leaf() it needs to get the sibling's WRITE_LOCK(). )
>
> Thanks,
>
> -liubo
>
> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
> index 323e12c..4a64fdd 100644
> --- a/fs/btrfs/tree-log.c
> +++ b/fs/btrfs/tree-log.c
> @@ -4956,6 +4956,7 @@ process_leaf:
>                         if (di_key.type == BTRFS_ROOT_ITEM_KEY)
>                                 continue;
>
> +                       btrfs_release_path(path);
>                         di_inode = btrfs_iget(root->fs_info->sb, &di_key,
>                                               root, NULL);
>                         if (IS_ERR(di_inode)) {
> @@ -4971,7 +4972,6 @@ process_leaf:
>                         ctx->log_new_dentries = false;
>                         if (type == BTRFS_FT_DIR)
>                                 log_mode = LOG_INODE_ALL;
> -                       btrfs_release_path(path);
>                         ret = btrfs_log_inode(trans, root, di_inode,
>                                               log_mode, 0, LLONG_MAX, ctx);
>                         iput(di_inode);
>
>

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Liu Bo]

On Fri, Feb 12, 2016 at 02:03:15AM +0500, Михаил Гаврилов wrote:
> Thanks guys, I appreciate your's work.
> In which kernel this patch would landed?

You can try it on your 4.2.3 kernel or the latest 4.5, but I guess it
doesn't not fix the real deadlock you're hitting...

Thanks,

-liubo

> 
> --
> Best Regards,
> Mike Gavrilov.
> 
> 
> 2016-02-12 0:18 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
> >
> > Really appreciate for collecting these, it should be helpful.
> >
> > Unfortunately I still could not figure out who's holding fs tree's root WRITE_LOCK so that others are blocked.
> >
> > A possible bug in log code (the follwing patch addressed it),
> >
> > - log_new_dir_dentries() is holding log tree's leaf READ_LOCK and may try
> >   to get fs tree's READ_LOCK via btrfs_iget() -> btrfs_lookup().
> >   (This is shown in the backtrac)
> >
> > - btrfs_log_inode() can call btrfs_search_forward() to get fs tree's
> >   leaf READ_LOCK and then call copy_items() -> btrfs_insert_empty_items()
> >   to acquire WRITE_LOCK of log tree's leaf and leaf's parent.
> >   (In the backtrace, this is blocked by item 1 because log_new_dir_dentries is
> >   holding a log tree leaf's READ_LOCK() which happens to be sibling to
> >   the leaf that btrfs_insert_empty_items() is accessing, when doing
> >   split_leaf() it needs to get the sibling's WRITE_LOCK(). )
> >
> > Thanks,
> >
> > -liubo
> >
> > diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
> > index 323e12c..4a64fdd 100644
> > --- a/fs/btrfs/tree-log.c
> > +++ b/fs/btrfs/tree-log.c
> > @@ -4956,6 +4956,7 @@ process_leaf:
> >                         if (di_key.type == BTRFS_ROOT_ITEM_KEY)
> >                                 continue;
> >
> > +                       btrfs_release_path(path);
> >                         di_inode = btrfs_iget(root->fs_info->sb, &di_key,
> >                                               root, NULL);
> >                         if (IS_ERR(di_inode)) {
> > @@ -4971,7 +4972,6 @@ process_leaf:
> >                         ctx->log_new_dentries = false;
> >                         if (type == BTRFS_FT_DIR)
> >                                 log_mode = LOG_INODE_ALL;
> > -                       btrfs_release_path(path);
> >                         ret = btrfs_log_inode(trans, root, di_inode,
> >                                               log_mode, 0, LLONG_MAX, ctx);
> >                         iput(di_inode);
> >
> >

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Chris Murphy]

On Thu, Feb 11, 2016 at 8:22 PM, Liu Bo <bo.li.liu@oracle.com> wrote:
> On Fri, Feb 12, 2016 at 02:03:15AM +0500, Михаил Гаврилов wrote:
>> Thanks guys, I appreciate your's work.
>> In which kernel this patch would landed?
>
> You can try it on your 4.2.3 kernel or the latest 4.5, but I guess it
> doesn't not fix the real deadlock you're hitting...

I think the question is whether the patch is already in a stable
kernel, or mainline, or not yet merged?


-- 
Chris Murphy

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Михаил Гаврилов]

2016-02-12 8:22 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
> You can try it on your 4.2.3 kernel or the latest 4.5, but I guess it
> doesn't not fix the real deadlock you're hitting...

It means it is not final patch? you continue investigate problem? Can
I help you?

--
Best Regards,
Mike Gavrilov.

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Liu Bo]

On Sat, Feb 13, 2016 at 12:15:08AM +0500, Михаил Гаврилов wrote:
> 2016-02-12 8:22 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
> > You can try it on your 4.2.3 kernel or the latest 4.5, but I guess it
> > doesn't not fix the real deadlock you're hitting...
> 
> It means it is not final patch? you continue investigate problem? Can
> I help you?

Yeah, it's not the final patch, you can apply it and see if the deadlock
will happen again.

Unless we can get a way to reproduce it, I'm afraid there's little things we can  do here.

Thanks,

-liubo

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Liu Bo]

On Thu, Feb 11, 2016 at 08:38:36PM -0700, Chris Murphy wrote:
> On Thu, Feb 11, 2016 at 8:22 PM, Liu Bo <bo.li.liu@oracle.com> wrote:
> > On Fri, Feb 12, 2016 at 02:03:15AM +0500, Михаил Гаврилов wrote:
> >> Thanks guys, I appreciate your's work.
> >> In which kernel this patch would landed?
> >
> > You can try it on your 4.2.3 kernel or the latest 4.5, but I guess it
> > doesn't not fix the real deadlock you're hitting...
> 
> I think the question is whether the patch is already in a stable
> kernel, or mainline, or not yet merged?

Oh, it's not merged, just a quick patch to see if it can fix the deadlock.

Thanks,

-liubo

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Михаил Гаврилов]

Sorry, I have not yet had time to apply your patch.

And get hang again when launch web browser.

Here new logs: http://btrfs.sy24.ru/kernel-sysrqw-btrfscleaner770blocked-3.txt

Addition info: when btrfs partition hangs also hang GUI it is normal?
For grab logs I switch to tty3 (Ctrl - Alt - F3)



--
Best Regards,
Mike Gavrilov.


2016-02-13 1:34 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
> On Sat, Feb 13, 2016 at 12:15:08AM +0500, Михаил Гаврилов wrote:
>> 2016-02-12 8:22 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
>> > You can try it on your 4.2.3 kernel or the latest 4.5, but I guess it
>> > doesn't not fix the real deadlock you're hitting...
>>
>> It means it is not final patch? you continue investigate problem? Can
>> I help you?
>
> Yeah, it's not the final patch, you can apply it and see if the deadlock
> will happen again.
>
> Unless we can get a way to reproduce it, I'm afraid there's little things we can  do here.
>
> Thanks,
>
> -liubo

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Liu Bo]

Hi Mike,
On Sun, Feb 14, 2016 at 12:23:16AM +0500, Михаил Гаврилов wrote:
> Sorry, I have not yet had time to apply your patch.
> 
> And get hang again when launch web browser.
> 
> Here new logs: http://btrfs.sy24.ru/kernel-sysrqw-btrfscleaner770blocked-3.txt

The logs show,
every hung process is waiting for fs tree root's WRITE_LOCK, but someone who's
holding the WRITE_LOCK is not reflected here.

Only one suspicious process is 
"Chrome_FileThre D ffff8807fe1d7a18 10360 22486   2826 0x00000000"
it's also waiting on btrfs_tree_lock(), but I can't tell whether it
waits for the fs tree root node's lock or the children node's lock.

Hmm, sorry for not being helpful, but I was wondering if this also
occurs on the latest btrfs(4.5) or is it possible to give it a shot?

The best result is that it's been fixed by one commit in 4.5.

> 
> Addition info: when btrfs partition hangs also hang GUI it is normal?
> For grab logs I switch to tty3 (Ctrl - Alt - F3)

I'm afraid the answer is yes because GUI needs to read files (like
config files) from the underlying partition.

Thanks,

-liubo

> 
> 
> 
> --
> Best Regards,
> Mike Gavrilov.
> 
> 
> 2016-02-13 1:34 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
> > On Sat, Feb 13, 2016 at 12:15:08AM +0500, Михаил Гаврилов wrote:
> >> 2016-02-12 8:22 GMT+05:00 Liu Bo <bo.li.liu@oracle.com>:
> >> > You can try it on your 4.2.3 kernel or the latest 4.5, but I guess it
> >> > doesn't not fix the real deadlock you're hitting...
> >>
> >> It means it is not final patch? you continue investigate problem? Can
> >> I help you?
> >
> > Yeah, it's not the final patch, you can apply it and see if the deadlock
> > will happen again.
> >
> > Unless we can get a way to reproduce it, I'm afraid there's little things we can  do here.
> >
> > Thanks,
> >
> > -liubo

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Roman Mamedov]

[-- Attachment #1: Type: text/plain, Size: 1663 bytes --]

On Sun, 14 Feb 2016 13:32:24 -0800
Liu Bo <bo.li.liu@oracle.com> wrote:

> Hi Mike,
> On Sun, Feb 14, 2016 at 12:23:16AM +0500, Михаил Гаврилов wrote:
> > Sorry, I have not yet had time to apply your patch.
> > 
> > And get hang again when launch web browser.
> > 
> > Here new logs: http://btrfs.sy24.ru/kernel-sysrqw-btrfscleaner770blocked-3.txt
> 
> The logs show,
> every hung process is waiting for fs tree root's WRITE_LOCK, but someone who's
> holding the WRITE_LOCK is not reflected here.
> 
> Only one suspicious process is 
> "Chrome_FileThre D ffff8807fe1d7a18 10360 22486   2826 0x00000000"
> it's also waiting on btrfs_tree_lock(), but I can't tell whether it
> waits for the fs tree root node's lock or the children node's lock.
> 
> Hmm, sorry for not being helpful, but I was wondering if this also
> occurs on the latest btrfs(4.5) or is it possible to give it a shot?
> 
> The best result is that it's been fixed by one commit in 4.5.

FWIW I had a persistently repeating deadlock on 4.1 and 4.3, but after upgrade
to 4.4 it no longer happens. Not sure if it might be related or not, the
backtrace seems similar: http://www.spinics.net/lists/linux-btrfs/msg50951.html

My advice would be to try 4.4, but don't forget to manually add the
nocow/enospc patch: https://patchwork.kernel.org/patch/7967161/

None of the vanilla 4.1, 4.3 or 4.4 should be considered usable with Btrfs at
the moment. The latest kernel series which works out of the box was 3.18;
patched 4.4 also works fine so far, but I wonder if that patch makes it into
4.4.2 or gets forgotten/etc again.

-- 
With respect,
Roman

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Christian Rohmann]

On 02/14/2016 11:42 PM, Roman Mamedov wrote:
> FWIW I had a persistently repeating deadlock on 4.1 and 4.3, but
> after upgrade to 4.4 it no longer happens.


Apparently also with 4.4 there is some sort of blocking happening ...
just at 38580:

---- cut ----

[Wed Feb 17 16:43:48 2016] INFO: task btrfs-cleaner:38580 blocked for
more than 120 seconds.
[Wed Feb 17 16:43:48 2016]       Not tainted 4.4.0-customkernel #1
[Wed Feb 17 16:43:48 2016] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
[Wed Feb 17 16:43:48 2016] btrfs-cleaner   D ffff882c27295dc0     0
38580      2 0x00000000
[Wed Feb 17 16:43:48 2016]  ffff882c16fa6480 ffff88161a980280
ffff882a3d744000 ffff882a3d743df8
[Wed Feb 17 16:43:48 2016]  ffff8815fead7104 ffff882c16fa6480
00000000ffffffff ffff8815fead7108
[Wed Feb 17 16:43:48 2016]  ffffffff81559a31 ffff8815fead7100
ffffffff81559cba ffffffff8155b5a0
[Wed Feb 17 16:43:48 2016] Call Trace:
[Wed Feb 17 16:43:48 2016]  [<ffffffff81559a31>] ? schedule+0x31/0x80
[Wed Feb 17 16:43:48 2016]  [<ffffffff81559cba>] ?
schedule_preempt_disabled+0xa/0x10
[Wed Feb 17 16:43:48 2016]  [<ffffffff8155b5a0>] ?
__mutex_lock_slowpath+0x90/0x110
[Wed Feb 17 16:43:48 2016]  [<ffffffff8155b63b>] ? mutex_lock+0x1b/0x30
[Wed Feb 17 16:43:48 2016]  [<ffffffffa01bf51e>] ?
btrfs_delete_unused_bgs+0xee/0x3f0 [btrfs]
[Wed Feb 17 16:43:48 2016]  [<ffffffff81559396>] ? __schedule+0x286/0x8f0
[Wed Feb 17 16:43:48 2016]  [<ffffffffa01c6ff7>] ?
cleaner_kthread+0x1a7/0x200 [btrfs]
[Wed Feb 17 16:43:48 2016]  [<ffffffffa01c6e50>] ?
check_leaf+0x340/0x340 [btrfs]
[Wed Feb 17 16:43:48 2016]  [<ffffffff8108df6f>] ? kthread+0xcf/0xf0
[Wed Feb 17 16:43:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
[Wed Feb 17 16:43:48 2016]  [<ffffffff8155d74f>] ? ret_from_fork+0x3f/0x70
[Wed Feb 17 16:43:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50

[Wed Feb 17 17:23:48 2016] INFO: task btrfs-cleaner:38580 blocked for
more than 120 seconds.
[Wed Feb 17 17:23:48 2016]       Not tainted 4.4.0-customkernel #1
[Wed Feb 17 17:23:48 2016] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
[Wed Feb 17 17:23:48 2016] btrfs-cleaner   D ffff881627a35dc0     0
38580      2 0x00000000
[Wed Feb 17 17:23:48 2016]  ffff882c16fa6480 ffff88161a956f00
ffff882a3d744000 ffff882a3d743df8
[Wed Feb 17 17:23:48 2016]  ffff8815fead7104 ffff882c16fa6480
00000000ffffffff ffff8815fead7108
[Wed Feb 17 17:23:48 2016]  ffffffff81559a31 ffff8815fead7100
ffffffff81559cba ffffffff8155b5a0
[Wed Feb 17 17:23:48 2016] Call Trace:
[Wed Feb 17 17:23:48 2016]  [<ffffffff81559a31>] ? schedule+0x31/0x80
[Wed Feb 17 17:23:48 2016]  [<ffffffff81559cba>] ?
schedule_preempt_disabled+0xa/0x10
[Wed Feb 17 17:23:48 2016]  [<ffffffff8155b5a0>] ?
__mutex_lock_slowpath+0x90/0x110
[Wed Feb 17 17:23:48 2016]  [<ffffffff8155b63b>] ? mutex_lock+0x1b/0x30
[Wed Feb 17 17:23:48 2016]  [<ffffffffa01bf51e>] ?
btrfs_delete_unused_bgs+0xee/0x3f0 [btrfs]
[Wed Feb 17 17:23:48 2016]  [<ffffffff81559396>] ? __schedule+0x286/0x8f0
[Wed Feb 17 17:23:48 2016]  [<ffffffffa01c6ff7>] ?
cleaner_kthread+0x1a7/0x200 [btrfs]
[Wed Feb 17 17:23:48 2016]  [<ffffffffa01c6e50>] ?
check_leaf+0x340/0x340 [btrfs]
[Wed Feb 17 17:23:48 2016]  [<ffffffff8108df6f>] ? kthread+0xcf/0xf0
[Wed Feb 17 17:23:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
[Wed Feb 17 17:23:48 2016]  [<ffffffff8155d74f>] ? ret_from_fork+0x3f/0x70
[Wed Feb 17 17:23:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50

[Wed Feb 17 17:57:48 2016] INFO: task btrfs-cleaner:38580 blocked for
more than 120 seconds.
[Wed Feb 17 17:57:48 2016]       Not tainted 4.4.0-customkernel #1
[Wed Feb 17 17:57:48 2016] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
[Wed Feb 17 17:57:48 2016] btrfs-cleaner   D ffff881627a95dc0     0
38580      2 0x00000000
[Wed Feb 17 17:57:48 2016]  ffff882c16fa6480 ffff88161a980fc0
ffff882a3d744000 ffff882a3d743df8
[Wed Feb 17 17:57:48 2016]  ffff8815fead7104 ffff882c16fa6480
00000000ffffffff ffff8815fead7108
[Wed Feb 17 17:57:48 2016]  ffffffff81559a31 ffff8815fead7100
ffffffff81559cba ffffffff8155b5a0
[Wed Feb 17 17:57:48 2016] Call Trace:
[Wed Feb 17 17:57:48 2016]  [<ffffffff81559a31>] ? schedule+0x31/0x80
[Wed Feb 17 17:57:48 2016]  [<ffffffff81559cba>] ?
schedule_preempt_disabled+0xa/0x10
[Wed Feb 17 17:57:48 2016]  [<ffffffff8155b5a0>] ?
__mutex_lock_slowpath+0x90/0x110
[Wed Feb 17 17:57:48 2016]  [<ffffffff8155b63b>] ? mutex_lock+0x1b/0x30
[Wed Feb 17 17:57:48 2016]  [<ffffffffa01bf51e>] ?
btrfs_delete_unused_bgs+0xee/0x3f0 [btrfs]
[Wed Feb 17 17:57:48 2016]  [<ffffffff81559396>] ? __schedule+0x286/0x8f0
[Wed Feb 17 17:57:48 2016]  [<ffffffffa01c6ff7>] ?
cleaner_kthread+0x1a7/0x200 [btrfs]
[Wed Feb 17 17:57:48 2016]  [<ffffffffa01c6e50>] ?
check_leaf+0x340/0x340 [btrfs]
[Wed Feb 17 17:57:48 2016]  [<ffffffff8108df6f>] ? kthread+0xcf/0xf0
[Wed Feb 17 17:57:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
[Wed Feb 17 17:57:48 2016]  [<ffffffff8155d74f>] ? ret_from_fork+0x3f/0x70
[Wed Feb 17 17:57:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50


---- cut ----

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Liu Bo]

On Thu, Feb 18, 2016 at 01:35:24PM +0100, Christian Rohmann wrote:
> 
> 
> On 02/14/2016 11:42 PM, Roman Mamedov wrote:
> > FWIW I had a persistently repeating deadlock on 4.1 and 4.3, but
> > after upgrade to 4.4 it no longer happens.
> 
> 
> Apparently also with 4.4 there is some sort of blocking happening ...
> just at 38580:

OK, what does 'sysrq-w' say?

Thanks,

-liubo

> 
> ---- cut ----
> 
> [Wed Feb 17 16:43:48 2016] INFO: task btrfs-cleaner:38580 blocked for
> more than 120 seconds.
> [Wed Feb 17 16:43:48 2016]       Not tainted 4.4.0-customkernel #1
> [Wed Feb 17 16:43:48 2016] "echo 0 >
> /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> [Wed Feb 17 16:43:48 2016] btrfs-cleaner   D ffff882c27295dc0     0
> 38580      2 0x00000000
> [Wed Feb 17 16:43:48 2016]  ffff882c16fa6480 ffff88161a980280
> ffff882a3d744000 ffff882a3d743df8
> [Wed Feb 17 16:43:48 2016]  ffff8815fead7104 ffff882c16fa6480
> 00000000ffffffff ffff8815fead7108
> [Wed Feb 17 16:43:48 2016]  ffffffff81559a31 ffff8815fead7100
> ffffffff81559cba ffffffff8155b5a0
> [Wed Feb 17 16:43:48 2016] Call Trace:
> [Wed Feb 17 16:43:48 2016]  [<ffffffff81559a31>] ? schedule+0x31/0x80
> [Wed Feb 17 16:43:48 2016]  [<ffffffff81559cba>] ?
> schedule_preempt_disabled+0xa/0x10
> [Wed Feb 17 16:43:48 2016]  [<ffffffff8155b5a0>] ?
> __mutex_lock_slowpath+0x90/0x110
> [Wed Feb 17 16:43:48 2016]  [<ffffffff8155b63b>] ? mutex_lock+0x1b/0x30
> [Wed Feb 17 16:43:48 2016]  [<ffffffffa01bf51e>] ?
> btrfs_delete_unused_bgs+0xee/0x3f0 [btrfs]
> [Wed Feb 17 16:43:48 2016]  [<ffffffff81559396>] ? __schedule+0x286/0x8f0
> [Wed Feb 17 16:43:48 2016]  [<ffffffffa01c6ff7>] ?
> cleaner_kthread+0x1a7/0x200 [btrfs]
> [Wed Feb 17 16:43:48 2016]  [<ffffffffa01c6e50>] ?
> check_leaf+0x340/0x340 [btrfs]
> [Wed Feb 17 16:43:48 2016]  [<ffffffff8108df6f>] ? kthread+0xcf/0xf0
> [Wed Feb 17 16:43:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
> [Wed Feb 17 16:43:48 2016]  [<ffffffff8155d74f>] ? ret_from_fork+0x3f/0x70
> [Wed Feb 17 16:43:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
> 
> [Wed Feb 17 17:23:48 2016] INFO: task btrfs-cleaner:38580 blocked for
> more than 120 seconds.
> [Wed Feb 17 17:23:48 2016]       Not tainted 4.4.0-customkernel #1
> [Wed Feb 17 17:23:48 2016] "echo 0 >
> /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> [Wed Feb 17 17:23:48 2016] btrfs-cleaner   D ffff881627a35dc0     0
> 38580      2 0x00000000
> [Wed Feb 17 17:23:48 2016]  ffff882c16fa6480 ffff88161a956f00
> ffff882a3d744000 ffff882a3d743df8
> [Wed Feb 17 17:23:48 2016]  ffff8815fead7104 ffff882c16fa6480
> 00000000ffffffff ffff8815fead7108
> [Wed Feb 17 17:23:48 2016]  ffffffff81559a31 ffff8815fead7100
> ffffffff81559cba ffffffff8155b5a0
> [Wed Feb 17 17:23:48 2016] Call Trace:
> [Wed Feb 17 17:23:48 2016]  [<ffffffff81559a31>] ? schedule+0x31/0x80
> [Wed Feb 17 17:23:48 2016]  [<ffffffff81559cba>] ?
> schedule_preempt_disabled+0xa/0x10
> [Wed Feb 17 17:23:48 2016]  [<ffffffff8155b5a0>] ?
> __mutex_lock_slowpath+0x90/0x110
> [Wed Feb 17 17:23:48 2016]  [<ffffffff8155b63b>] ? mutex_lock+0x1b/0x30
> [Wed Feb 17 17:23:48 2016]  [<ffffffffa01bf51e>] ?
> btrfs_delete_unused_bgs+0xee/0x3f0 [btrfs]
> [Wed Feb 17 17:23:48 2016]  [<ffffffff81559396>] ? __schedule+0x286/0x8f0
> [Wed Feb 17 17:23:48 2016]  [<ffffffffa01c6ff7>] ?
> cleaner_kthread+0x1a7/0x200 [btrfs]
> [Wed Feb 17 17:23:48 2016]  [<ffffffffa01c6e50>] ?
> check_leaf+0x340/0x340 [btrfs]
> [Wed Feb 17 17:23:48 2016]  [<ffffffff8108df6f>] ? kthread+0xcf/0xf0
> [Wed Feb 17 17:23:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
> [Wed Feb 17 17:23:48 2016]  [<ffffffff8155d74f>] ? ret_from_fork+0x3f/0x70
> [Wed Feb 17 17:23:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
> 
> [Wed Feb 17 17:57:48 2016] INFO: task btrfs-cleaner:38580 blocked for
> more than 120 seconds.
> [Wed Feb 17 17:57:48 2016]       Not tainted 4.4.0-customkernel #1
> [Wed Feb 17 17:57:48 2016] "echo 0 >
> /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> [Wed Feb 17 17:57:48 2016] btrfs-cleaner   D ffff881627a95dc0     0
> 38580      2 0x00000000
> [Wed Feb 17 17:57:48 2016]  ffff882c16fa6480 ffff88161a980fc0
> ffff882a3d744000 ffff882a3d743df8
> [Wed Feb 17 17:57:48 2016]  ffff8815fead7104 ffff882c16fa6480
> 00000000ffffffff ffff8815fead7108
> [Wed Feb 17 17:57:48 2016]  ffffffff81559a31 ffff8815fead7100
> ffffffff81559cba ffffffff8155b5a0
> [Wed Feb 17 17:57:48 2016] Call Trace:
> [Wed Feb 17 17:57:48 2016]  [<ffffffff81559a31>] ? schedule+0x31/0x80
> [Wed Feb 17 17:57:48 2016]  [<ffffffff81559cba>] ?
> schedule_preempt_disabled+0xa/0x10
> [Wed Feb 17 17:57:48 2016]  [<ffffffff8155b5a0>] ?
> __mutex_lock_slowpath+0x90/0x110
> [Wed Feb 17 17:57:48 2016]  [<ffffffff8155b63b>] ? mutex_lock+0x1b/0x30
> [Wed Feb 17 17:57:48 2016]  [<ffffffffa01bf51e>] ?
> btrfs_delete_unused_bgs+0xee/0x3f0 [btrfs]
> [Wed Feb 17 17:57:48 2016]  [<ffffffff81559396>] ? __schedule+0x286/0x8f0
> [Wed Feb 17 17:57:48 2016]  [<ffffffffa01c6ff7>] ?
> cleaner_kthread+0x1a7/0x200 [btrfs]
> [Wed Feb 17 17:57:48 2016]  [<ffffffffa01c6e50>] ?
> check_leaf+0x340/0x340 [btrfs]
> [Wed Feb 17 17:57:48 2016]  [<ffffffff8108df6f>] ? kthread+0xcf/0xf0
> [Wed Feb 17 17:57:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
> [Wed Feb 17 17:57:48 2016]  [<ffffffff8155d74f>] ? ret_from_fork+0x3f/0x70
> [Wed Feb 17 17:57:48 2016]  [<ffffffff8108dea0>] ? kthread_park+0x50/0x50
> 
> 
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Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Christian Rohmann]

Hey liubo,

thanks for the quick response.

On 02/18/2016 05:59 PM, Liu Bo wrote:
>> Apparently also with 4.4 there is some sort of blocking happening ...
>> > just at 38580:
> OK, what does 'sysrq-w' say?

The problem has not appeared again for some time. Do I need to catch it
right when it happens? If so, what evidence should I collect and how?



Regards

Christian

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Chris Murphy]

On Fri, Feb 19, 2016 at 9:00 AM, Christian Rohmann
<crohmann@netcologne.de> wrote:
> Hey liubo,
>
> thanks for the quick response.
>
> On 02/18/2016 05:59 PM, Liu Bo wrote:
>>> Apparently also with 4.4 there is some sort of blocking happening ...
>>> > just at 38580:
>> OK, what does 'sysrq-w' say?
>
> The problem has not appeared again for some time. Do I need to catch it
> right when it happens? If so, what evidence should I collect and how?

It's uncertain how your kernel is built so full documentation is here:
https://www.kernel.org/doc/Documentation/sysrq.txt

Anytime before or during the problem:
echo 1 >/proc/sys/kernel/sysrq

Once blocked tasks show up:
echo w > /proc/sysrq-trigger

journalctl -k -o short-monotonic -l > journal_sysrqw.txt    ## example

If you're not on a systemd system, all of this should get dumped into
rsyslogd messages, so you can go in there and extract the current boot
into a file to attach. It should also appear in dmesg of course but
sometimes the output is bigger than the default kernel message buffer.

-- 
Chris Murphy

Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Roman Mamedov]

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On Tue, 15 Mar 2016 09:18:14 +0500
Михаил Гаврилов <mikhail.v.gavrilov@gmail.com> wrote:

> Yesterday btrfs again hangs on kernel 4.4.5
> It's the same or another problem?

Seems different to me, as there's also defrag involved. Try removing and not
using the defrag mount option.

> This messages say that restore failed?

So you can't mount the FS anymore? Did you try btrfsck, what does it report?

-- 
With respect,
Roman

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Re: task btrfs-cleaner:770 blocked for more than 120 seconds.

[Михаил Гаврилов]

2016-03-16 14:01 GMT+05:00 Roman Mamedov <rm@romanrm.net>:
> On Tue, 15 Mar 2016 09:18:14 +0500
> Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> wrote:
>
>> Yesterday btrfs again hangs on kernel 4.4.5
>> It's the same or another problem?
>
> Seems different to me, as there's also defrag involved. Try removing and not
> using the defrag mount option.

How then defragment FS?

>
>> This messages say that restore failed?
>
> So you can't mount the FS anymore? Did you try btrfsck, what does it report?
>

FS is mounted, but after failure mount takes a long time (more than 4
min) and Fedora  stops boot  by timeout (system suggest enter under
root for maintance) after reboot again all fine.

I'm just afraid of losing data after this messages:
[  449.949206] BTRFS warning (device sdc1): failed to load free space
cache for block group 2286562574336, rebuilding it now
[  452.619318] BTRFS: open_ctree failed

or it does not mean anything terrible?

--
Best Regards,
Mike Gavrilov.