On Mon, Apr 17, 2023 at 1:42 AM Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote: > And talking about the "100% utilization", did you mean a single CPU core > is fully utilized by some btrfs thread? No, iostat reporting the disk is at "100%" utilization. > If so, it looks like qgroup is involved. > Did you just recently deleted one or more snapshots? If so, it's almost > certain qgroup is the cause of the 100% CPU utilization. No, I used to run snapraid-btrfs (uses snapper) but both projects are effectively orphaned. There's no snapshots left, but I used to run zygo/bees also on these disks but that also has basic problems (specifically mlock' on GBs of data when it's sitting completely idle for hours at a time). bees was not running when this happened (or for the duration of the uptime of the machine). > In that case, you can disable quota for that btrfs (permanently), or use > newer kernel which has a sysfs interface: > > /sys/fs/btrfs/<UUID>/qgroups/drop_subtree_threshold Thank you, I'll give it a go after the reboot here. I don't think I have quotas enabled but I did look at it at one point (I remember toggling on then off). > If you write some value like 3 into that file, btrfs would automatically > avoid such long CPU usage caused by large snapshot dropping. > > But talking about the XFS corruption, I'm not sure how btrfs can lead to > problems in XFS... All I/O seemed to be dead on the box. I tried to remove the same data again and the task hung... this time I was able to interrupt the removal and the box recovered. [92798.210656] INFO: task sync:1282043 blocked for more than 120 seconds. [92798.210683] Not tainted 5.19.0-38-generic #39~22.04.1-Ubuntu [92798.210707] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [92798.210735] task:sync state:D stack: 0 pid:1282043 ppid:1281934 flags:0x00004002 [92798.210739] Call Trace: [92798.210741] <TASK> [92798.210743] __schedule+0x257/0x5d0 [92798.210747] schedule+0x68/0x110 [92798.210750] wait_current_trans+0xde/0x140 [btrfs] [92798.210820] ? destroy_sched_domains_rcu+0x40/0x40 [92798.210824] start_transaction+0x34d/0x5f0 [btrfs] [92798.210895] btrfs_attach_transaction_barrier+0x23/0x70 [btrfs] [92798.210966] btrfs_sync_fs+0x4a/0x1c0 [btrfs] [92798.211029] ? vfs_fsync_range+0xa0/0xa0 [92798.211033] sync_fs_one_sb+0x26/0x40 [92798.211037] iterate_supers+0x9e/0x110 [92798.211041] ksys_sync+0x62/0xb0 [92798.211045] __do_sys_sync+0xe/0x20 [92798.211049] do_syscall_64+0x59/0x90 [92798.211052] entry_SYSCALL_64_after_hwframe+0x63/0xcd [92798.211057] RIP: 0033:0x7fd08471babb [92798.211059] RSP: 002b:00007ffd344545f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 [92798.211063] RAX: ffffffffffffffda RBX: 00007ffd344547d8 RCX: 00007fd08471babb [92798.211065] RDX: 00007fd084821101 RSI: 00007ffd344547d8 RDI: 00007fd0847d9e29 [92798.211067] RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 [92798.211069] R10: 0000556ba8b21e40 R11: 0000000000000246 R12: 0000556ba8acebc0 [92798.211071] R13: 0000556ba8acc19f R14: 00007fd08481942c R15: 0000556ba8acc034 [92798.211075] </TASK> Kyle. On Mon, Apr 17, 2023 at 1:42 AM Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote: > > > > On 2023/4/17 13:20, Kyle Sanderson wrote: > > The single btrfs disk was at 100% utilization and a wa of 50~, reading > > back at around 2MB/s. df and similar would simply freeze. Leading up > > to this I removed around 2T of data from a single btrfs disk. I > > managed to get most of the services shutdown and disks unmounted, but > > when the system came back up I had to use xfs_repair (for the first > > time in a very long time) to boot into my system. I likely should have > > just pulled the power... > > I didn't see any obvious btrfs related work involved in the call trace. > Thus I believe it's not really hanging in a waiting status. > > And talking about the "100% utilization", did you mean a single CPU core > is fully utilized by some btrfs thread? > > If so, it looks like qgroup is involved. > Did you just recently deleted one or more snapshots? If so, it's almost > certain qgroup is the cause of the 100% CPU utilization. > > In that case, you can disable quota for that btrfs (permanently), or use > newer kernel which has a sysfs interface: > > /sys/fs/btrfs/<UUID>/qgroups/drop_subtree_threshold > > If you write some value like 3 into that file, btrfs would automatically > avoid such long CPU usage caused by large snapshot dropping. > > But talking about the XFS corruption, I'm not sure how btrfs can lead to > problems in XFS... > > Thanks, > Qu > > > > [1147997.255020] INFO: task happywriter:3425205 blocked for more than > > 120 seconds. > > [1147997.255088] Not tainted 5.19.0-38-generic #39~22.04.1-Ubuntu > > [1147997.255114] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > disables this message. > > [1147997.255144] task:happywriter state:D stack: 0 pid:3425205 > > ppid:557021 flags:0x00004000 > > [1147997.255151] Call Trace: > > [1147997.255155] <TASK> > > [1147997.255160] __schedule+0x257/0x5d0 > > [1147997.255169] ? __schedule+0x25f/0x5d0 > > [1147997.255173] schedule+0x68/0x110 > > [1147997.255176] rwsem_down_write_slowpath+0x2ee/0x5a0 > > [1147997.255180] ? check_heap_object+0x100/0x1e0 > > [1147997.255185] down_write+0x4f/0x70 > > [1147997.255189] do_unlinkat+0x12b/0x2d0 > > [1147997.255194] __x64_sys_unlink+0x42/0x70 > > [1147997.255197] ? syscall_exit_to_user_mode+0x2a/0x50 > > [1147997.255201] do_syscall_64+0x59/0x90 > > [1147997.255204] ? do_syscall_64+0x69/0x90 > > [1147997.255207] ? sysvec_call_function_single+0x4e/0xb0 > > [1147997.255211] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > [1147997.255216] RIP: 0033:0x1202a57 > > [1147997.255220] RSP: 002b:00007fe467ffd4c8 EFLAGS: 00000246 ORIG_RAX: > > 0000000000000057 > > [1147997.255224] RAX: ffffffffffffffda RBX: 00007fe3a4e94d28 RCX: > > 0000000001202a57 > > [1147997.255226] RDX: 0000000000000000 RSI: 0000000000000000 RDI: > > 00007fe450054b60 > > [1147997.255228] RBP: 00007fe450054b60 R08: 0000000000000000 R09: > > 00000000000000e8 > > [1147997.255231] R10: 0000000000000001 R11: 0000000000000246 R12: > > 00007fe467ffd5b0 > > [1147997.255233] R13: 00007fe467ffd5f0 R14: 00007fe467ffd5e0 R15: > > 00007fe3a4e94d28 > > [1147997.255239] </TASK> > > [1148118.087966] INFO: task happywriter:3425205 blocked for more than > > 241 seconds. > > [1148118.088022] Not tainted 5.19.0-38-generic #39~22.04.1-Ubuntu > > [1148118.088048] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > disables this message. > > [1148118.088077] task:happywriter state:D stack: 0 pid:3425205 > > ppid:557021 flags:0x00004000 > > [1148118.088083] Call Trace: > > [1148118.088087] <TASK> > > [1148118.088093] __schedule+0x257/0x5d0 > > [1148118.088101] ? __schedule+0x25f/0x5d0 > > [1148118.088105] schedule+0x68/0x110 > > [1148118.088108] rwsem_down_write_slowpath+0x2ee/0x5a0 > > [1148118.088113] ? check_heap_object+0x100/0x1e0 > > [1148118.088118] down_write+0x4f/0x70 > > [1148118.088121] do_unlinkat+0x12b/0x2d0 > > [1148118.088126] __x64_sys_unlink+0x42/0x70 > > [1148118.088129] ? syscall_exit_to_user_mode+0x2a/0x50 > > [1148118.088133] do_syscall_64+0x59/0x90 > > [1148118.088136] ? do_syscall_64+0x69/0x90 > > [1148118.088139] ? sysvec_call_function_single+0x4e/0xb0 > > [1148118.088142] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > [1148118.088148] RIP: 0033:0x1202a57 > > [1148118.088151] RSP: 002b:00007fe467ffd4c8 EFLAGS: 00000246 ORIG_RAX: > > 0000000000000057 > > [1148118.088155] RAX: ffffffffffffffda RBX: 00007fe3a4e94d28 RCX: > > 0000000001202a57 > > [1148118.088158] RDX: 0000000000000000 RSI: 0000000000000000 RDI: > > 00007fe450054b60 > > [1148118.088160] RBP: 00007fe450054b60 R08: 0000000000000000 R09: > > 00000000000000e8 > > [1148118.088162] R10: 0000000000000001 R11: 0000000000000246 R12: > > 00007fe467ffd5b0 > > [1148118.088164] R13: 00007fe467ffd5f0 R14: 00007fe467ffd5e0 R15: > > 00007fe3a4e94d28 > > [1148118.088170] </TASK> > > [1148238.912688] INFO: task kcompactd0:70 blocked for more than 120 seconds. > > [1148238.912741] Not tainted 5.19.0-38-generic #39~22.04.1-Ubuntu > > [1148238.912767] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > disables this message. > > [1148238.912796] task:kcompactd0 state:D stack: 0 pid: 70 > > ppid: 2 flags:0x00004000 > > [1148238.912803] Call Trace: > > [1148238.912806] <TASK> > > [1148238.912812] __schedule+0x257/0x5d0 > > [1148238.912821] schedule+0x68/0x110 > > [1148238.912824] io_schedule+0x46/0x80 > > [1148238.912827] folio_wait_bit_common+0x14c/0x3a0 > > [1148238.912833] ? filemap_invalidate_unlock_two+0x50/0x50 > > [1148238.912838] __folio_lock+0x17/0x30 > > [1148238.912842] __unmap_and_move.constprop.0+0x39c/0x640 > > [1148238.912847] ? free_unref_page+0xe3/0x190 > > [1148238.912852] ? move_freelist_tail+0xe0/0xe0 > > [1148238.912855] ? move_freelist_tail+0xe0/0xe0 > > [1148238.912858] unmap_and_move+0x7d/0x4e0 > > [1148238.912862] migrate_pages+0x3b8/0x770 > > [1148238.912867] ? move_freelist_tail+0xe0/0xe0 > > [1148238.912870] ? isolate_freepages+0x2f0/0x2f0 > > [1148238.912874] compact_zone+0x2ca/0x620 > > [1148238.912878] proactive_compact_node+0x8a/0xe0 > > [1148238.912883] kcompactd+0x21c/0x4e0 > > [1148238.912886] ? destroy_sched_domains_rcu+0x40/0x40 > > [1148238.912892] ? kcompactd_do_work+0x240/0x240 > > [1148238.912896] kthread+0xeb/0x120 > > [1148238.912900] ? kthread_complete_and_exit+0x20/0x20 > > [1148238.912904] ret_from_fork+0x1f/0x30 > > [1148238.912911] </TASK> > > [1148238.913163] INFO: task happywriter:3425205 blocked for more than > > 362 seconds. > > [1148238.913195] Not tainted 5.19.0-38-generic #39~22.04.1-Ubuntu > > [1148238.913220] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > disables this message. > > [1148238.913250] task:happywriter state:D stack: 0 pid:3425205 > > ppid:557021 flags:0x00004000 > > [1148238.913254] Call Trace: > > [1148238.913256] <TASK> > > [1148238.913259] __schedule+0x257/0x5d0 > > [1148238.913264] ? __schedule+0x25f/0x5d0 > > [1148238.913267] schedule+0x68/0x110 > > [1148238.913270] rwsem_down_write_slowpath+0x2ee/0x5a0 > > [1148238.913276] ? check_heap_object+0x100/0x1e0 > > [1148238.913280] down_write+0x4f/0x70 > > [1148238.913284] do_unlinkat+0x12b/0x2d0 > > [1148238.913288] __x64_sys_unlink+0x42/0x70 > > [1148238.913292] ? syscall_exit_to_user_mode+0x2a/0x50 > > [1148238.913296] do_syscall_64+0x59/0x90 > > [1148238.913299] ? do_syscall_64+0x69/0x90 > > [1148238.913301] ? sysvec_call_function_single+0x4e/0xb0 > > [1148238.913305] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > [1148238.913310] RIP: 0033:0x1202a57 > > [1148238.913315] RSP: 002b:00007fe467ffd4c8 EFLAGS: 00000246 ORIG_RAX: > > 0000000000000057 > > [1148238.913319] RAX: ffffffffffffffda RBX: 00007fe3a4e94d28 RCX: > > 0000000001202a57 > > [1148238.913321] RDX: 0000000000000000 RSI: 0000000000000000 RDI: > > 00007fe450054b60 > > [1148238.913323] RBP: 00007fe450054b60 R08: 0000000000000000 R09: > > 00000000000000e8 > > [1148238.913325] R10: 0000000000000001 R11: 0000000000000246 R12: > > 00007fe467ffd5b0 > > [1148238.913328] R13: 00007fe467ffd5f0 R14: 00007fe467ffd5e0 R15: > > 00007fe3a4e94d28 > > [1148238.913333] </TASK> > > [1148238.913429] INFO: task kworker/u16:20:3402199 blocked for more > > than 120 seconds. > > [1148238.913459] Not tainted 5.19.0-38-generic #39~22.04.1-Ubuntu > > [1148238.913496] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > disables this message. > > [1148238.913527] task:kworker/u16:20 state:D stack: 0 pid:3402199 > > ppid: 2 flags:0x00004000 > > [1148238.913533] Workqueue: events_unbound io_ring_exit_work > > [1148238.913539] Call Trace: > > [1148238.913541] <TASK> > > [1148238.913544] __schedule+0x257/0x5d0 > > [1148238.913548] schedule+0x68/0x110 > > [1148238.913551] schedule_timeout+0x122/0x160 > > [1148238.913556] __wait_for_common+0x8f/0x190 > > [1148238.913559] ? usleep_range_state+0xa0/0xa0 > > [1148238.913564] wait_for_completion+0x24/0x40 > > [1148238.913567] io_ring_exit_work+0x186/0x1e9 > > [1148238.913571] ? io_uring_del_tctx_node+0xbf/0xbf > > [1148238.913576] process_one_work+0x21c/0x400 > > [1148238.913579] worker_thread+0x50/0x3f0 > > [1148238.913583] ? rescuer_thread+0x3a0/0x3a0 > > [1148238.913586] kthread+0xeb/0x120 > > [1148238.913590] ? kthread_complete_and_exit+0x20/0x20 > > [1148238.913594] ret_from_fork+0x1f/0x30 > > [1148238.913600] </TASK> > > [1148238.913607] INFO: task stat:3434604 blocked for more than 120 seconds. > > [1148238.913633] Not tainted 5.19.0-38-generic #39~22.04.1-Ubuntu > > [1148238.913658] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > disables this message. > > [1148238.913687] task:stat state:D stack: 0 pid:3434604 > > ppid:3396625 flags:0x00004004 > > [1148238.913691] Call Trace: > > [1148238.913693] <TASK> > > [1148238.913695] __schedule+0x257/0x5d0 > > [1148238.913699] schedule+0x68/0x110 > > [1148238.913703] request_wait_answer+0x13f/0x220 > > [1148238.913708] ? destroy_sched_domains_rcu+0x40/0x40 > > [1148238.913713] fuse_simple_request+0x1bb/0x370 > > [1148238.913717] fuse_do_getattr+0xda/0x320 > > [1148238.913720] ? try_to_unlazy+0x5b/0xd0 > > [1148238.913726] fuse_update_get_attr+0xb3/0xf0 > > [1148238.913730] fuse_getattr+0x87/0xd0 > > [1148238.913733] vfs_getattr_nosec+0xba/0x100 > > [1148238.913737] vfs_statx+0xa9/0x140 > > [1148238.913741] vfs_fstatat+0x59/0x80 > > [1148238.913744] __do_sys_newlstat+0x38/0x80 > > [1148238.913750] __x64_sys_newlstat+0x16/0x20 > > [1148238.913753] do_syscall_64+0x59/0x90 > > [1148238.913757] ? handle_mm_fault+0xba/0x2a0 > > [1148238.913761] ? exit_to_user_mode_prepare+0xaf/0xd0 > > [1148238.913765] ? irqentry_exit_to_user_mode+0x9/0x20 > > [1148238.913769] ? irqentry_exit+0x43/0x50 > > [1148238.913772] ? exc_page_fault+0x92/0x1b0 > > [1148238.913776] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > [1148238.913780] RIP: 0033:0x7fa76960d6ea > > [1148238.913783] RSP: 002b:00007ffe6d011878 EFLAGS: 00000246 ORIG_RAX: > > 0000000000000006 > > [1148238.913787] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: > > 00007fa76960d6ea > > [1148238.913789] RDX: 00007ffe6d011890 RSI: 00007ffe6d011890 RDI: > > 00007ffe6d01290b > > [1148238.913791] RBP: 00007ffe6d011a70 R08: 0000000000000001 R09: > > 0000000000000000 > > [1148238.913793] R10: fffffffffffff3ce R11: 0000000000000246 R12: > > 0000000000000000 > > [1148238.913795] R13: 000055feff0d2960 R14: 00007ffe6d011a68 R15: > > 00007ffe6d01290b > > [1148238.913800] </TASK>
