INFO: task kworker/u8:7:2912 blocked for more than 145 seconds. Not tainted 6.11.0-syzkaller-11653-g3630400697a3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:7 state:D stack:20088 pid:2912 tgid:2912 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-11) Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 io_schedule+0x8d/0x110 kernel/sched/core.c:7552 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1309 folio_lock include/linux/pagemap.h:1148 [inline] writeback_get_folio mm/page-writeback.c:2496 [inline] writeback_iter+0x992/0x18d0 mm/page-writeback.c:2590 write_cache_pages+0xb1/0x230 mm/page-writeback.c:2639 bch2_writepages+0x14f/0x380 fs/bcachefs/fs-io-buffered.c:639 do_writepages+0x35d/0x870 mm/page-writeback.c:2683 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1658 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1954 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2025 wb_writeback+0x42f/0xbd0 fs/fs-writeback.c:2136 wb_check_background_flush fs/fs-writeback.c:2206 [inline] wb_do_writeback fs/fs-writeback.c:2294 [inline] wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2321 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task syz-executor:5981 blocked for more than 147 seconds. Not tainted 6.11.0-syzkaller-11653-g3630400697a3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20096 pid:5981 tgid:5981 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 kthread_stop+0x19e/0x640 kernel/kthread.c:710 bch2_copygc_stop+0x4f/0x150 fs/bcachefs/movinggc.c:405 __bch2_fs_read_only+0x47/0x430 fs/bcachefs/super.c:264 bch2_fs_read_only+0xb57/0x1200 fs/bcachefs/super.c:354 __bch2_fs_stop+0x105/0x540 fs/bcachefs/super.c:619 generic_shutdown_super+0x139/0x2d0 fs/super.c:642 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2179 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3a1e17f327 RSP: 002b:00007fff3539fd08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f3a1e17f327 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff3539fdc0 RBP: 00007fff3539fdc0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff353a0e40 R13: 00007f3a1e1f0134 R14: 000000000001ea11 R15: 00007fff353a0e80 INFO: task syz.3.106:6415 blocked for more than 149 seconds. Not tainted 6.11.0-syzkaller-11653-g3630400697a3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.106 state:D stack:25568 pid:6415 tgid:6395 ppid:6163 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 io_schedule+0x8d/0x110 kernel/sched/core.c:7552 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1309 folio_wait_writeback+0xe7/0x1e0 mm/page-writeback.c:3189 folio_prepare_writeback mm/page-writeback.c:2455 [inline] writeback_get_folio mm/page-writeback.c:2497 [inline] writeback_iter+0xb18/0x18d0 mm/page-writeback.c:2590 write_cache_pages+0xb1/0x230 mm/page-writeback.c:2639 bch2_writepages+0x14f/0x380 fs/bcachefs/fs-io-buffered.c:639 do_writepages+0x35d/0x870 mm/page-writeback.c:2683 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:398 __filemap_fdatawrite_range mm/filemap.c:431 [inline] filemap_write_and_wait_range+0x192/0x280 mm/filemap.c:685 bch2_extend fs/bcachefs/fs-io.c:378 [inline] bchfs_truncate+0x64b/0xc70 fs/bcachefs/fs-io.c:431 notify_change+0xbca/0xe90 fs/attr.c:503 do_truncate+0x220/0x310 fs/open.c:65 vfs_truncate+0x2e1/0x3b0 fs/open.c:111 do_sys_truncate+0xdb/0x190 fs/open.c:134 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7e6637dff9 RSP: 002b:00007f7e671f9038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f7e66536058 RCX: 00007f7e6637dff9 RDX: 0000000000000000 RSI: 000000000000f000 RDI: 0000000020000080 RBP: 00007f7e663f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7e66536058 R15: 00007ffeafb7f3d8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701 3 locks held by kworker/u8:7/2912: #0: ffff8881436ef148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8881436ef148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90009e47d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90009e47d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff888057be80e0 (&type->s_umount_key#115){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 2 locks held by getty/4973: #0: ffff88814ba730a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5981: #0: ffff8880728ac0e0 (&type->s_umount_key#115){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880728ac0e0 (&type->s_umount_key#115){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880728ac0e0 (&type->s_umount_key#115){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffff888060600278 (&c->state_lock){+.+.}-{3:3}, at: __bch2_fs_stop+0xfd/0x540 fs/bcachefs/super.c:618 1 lock held by syz.3.106/6396: #0: ffff888057be8420 (sb_writers#32){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x220 fs/splice.c:1163 2 locks held by syz.3.106/6415: #0: ffff888057be8420 (sb_writers#32){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff888058f708c0 (&sb->s_type->i_mutex_key#41){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] #1: ffff888058f708c0 (&sb->s_type->i_mutex_key#41){+.+.}-{3:3}, at: do_truncate+0x20c/0x310 fs/open.c:63 5 locks held by bch-copygc/loop/6411: 1 lock held by bch-reclaim/loo/6428: 1 lock held by syz-executor/6903: #0: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz.4.223/7319: #0: ffff8880728ac0e0 (&type->s_umount_key#115){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880728ac0e0 (&type->s_umount_key#115){++++}-{3:3}, at: super_lock+0x196/0x400 fs/super.c:120 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-11653-g3630400697a3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6428 Comm: bch-reclaim/loo Not tainted 6.11.0-syzkaller-11653-g3630400697a3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:5766 [inline] RIP: 0010:preempt_count_add+0xa1/0x190 kernel/sched/core.c:5789 Code: 8b 05 2b d5 a0 7e 25 ff ff ff 7f 39 d8 75 44 4c 8b 74 24 18 4c 89 f7 e8 fd 62 0e 00 85 c0 74 0a 45 31 f6 31 ff e8 ef 62 0e 00 <65> 48 8b 1c 25 80 d7 03 00 48 81 c3 c8 14 00 00 48 89 d8 48 c1 e8 RSP: 0018:ffffc90002eaf810 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff8bc66200 RDX: 0000000000000000 RSI: ffffffff8c602040 RDI: 0000000000000000 RBP: ffff88806064a500 R08: ffffffff901bb66f R09: 1ffffffff20376cd R10: dffffc0000000000 R11: fffffbfff20376ce R12: ffff88806064a500 R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555568a4b608 CR3: 000000000e734000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock+0x12/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __bch2_next_write_buffer_flush_journal_buf+0x70/0x2a0 fs/bcachefs/journal.c:871 bch2_next_write_buffer_flush_journal_buf+0xa3/0x1b0 fs/bcachefs/journal.c:904 fetch_wb_keys_from_journal fs/bcachefs/btree_write_buffer.c:486 [inline] btree_write_buffer_flush_seq+0x18c/0x1bc0 fs/bcachefs/btree_write_buffer.c:503 bch2_btree_write_buffer_journal_flush+0x4e/0x80 fs/bcachefs/btree_write_buffer.c:525 journal_flush_pins+0x5f7/0xb20 fs/bcachefs/journal_reclaim.c:565 __bch2_journal_reclaim+0x789/0xdc0 fs/bcachefs/journal_reclaim.c:698 bch2_journal_reclaim_thread+0x174/0x560 fs/bcachefs/journal_reclaim.c:740 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244