INFO: task kworker/u8:2:34 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc7-syzkaller-00012-gdccb07f2914c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:13752 pid:34    tgid:34    ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-bcachefs-1)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 __closure_sync+0x259/0x2f0 lib/closure.c:135
 closure_sync include/linux/closure.h:194 [inline]
 __bch2_write+0x5458/0x5bd0 fs/bcachefs/io_write.c:1486
 bch2_write+0x947/0x1590 fs/bcachefs/io_write.c:1610
 closure_queue include/linux/closure.h:257 [inline]
 closure_call include/linux/closure.h:390 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:468 [inline]
 __bch2_writepage+0x1416/0x2b50 fs/bcachefs/fs-io-buffered.c:615
 write_cache_pages+0xd0/0x230 mm/page-writeback.c:2569
 bch2_writepages+0x14f/0x380 fs/bcachefs/fs-io-buffered.c:658
 do_writepages+0x359/0x870 mm/page-writeback.c:2612
 __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650
 writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2012
 wb_writeback+0x46b/0xce0 fs/fs-writeback.c:2119
 wb_check_background_flush fs/fs-writeback.c:2189 [inline]
 wb_do_writeback fs/fs-writeback.c:2277 [inline]
 wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2304
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
3 locks held by kworker/u8:2/34:
 #0: ffff88801aece948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline]
 #0: ffff88801aece948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348
 #1: ffffc90000aa7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline]
 #1: ffffc90000aa7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348
 #2: ffff8880793f40e0 (&type->s_umount_key#44){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561
1 lock held by klogd/4521:
 #0: ffff8880b953e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
2 locks held by getty/4836:
 #0: ffff88802a79f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f0e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc7-syzkaller-00012-gdccb07f2914c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 kernel/hung_task.c:380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5078 Comm: strace-static-x Not tainted 6.9.0-rc7-syzkaller-00012-gdccb07f2914c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:103 [inline]
RIP: 0010:lock_is_held_type+0x6a/0x190 kernel/locking/lockdep.c:5821
Code: 00 65 4c 8b 2c 25 80 d3 03 00 41 83 bd d4 0a 00 00 00 0f 85 da 00 00 00 41 89 f6 49 89 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 <4c> 8b 24 24 fa 48 c7 c7 80 c5 ca 8b e8 55 1b 00 00 65 ff 05 6e 09
RSP: 0018:ffffc900035b7bf8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff88802967da00
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8e334e00
RBP: ffffc900035b7d60 R08: ffffffff81e0f651 R09: 0000000000000000
R10: ffffc900035b7e40 R11: fffff520006b6fcc R12: 0000000000000000
R13: ffff88802967da00 R14: 00000000ffffffff R15: ffffffff8e334e00
FS:  00000000207713c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f44aa1ff000 CR3: 0000000023e48000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_is_held include/linux/lockdep.h:231 [inline]
 __might_resched+0xa5/0x780 kernel/sched/core.c:10159
 __might_fault+0x72/0x120 mm/memory.c:6217
 clear_rseq_cs kernel/rseq.c:257 [inline]
 rseq_ip_fixup kernel/rseq.c:291 [inline]
 __rseq_handle_notify_resume+0x63a/0x14e0 kernel/rseq.c:329
 rseq_handle_notify_resume include/linux/rseq.h:38 [inline]
 resume_user_mode_work include/linux/resume_user_mode.h:62 [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+0x114/0x370 kernel/entry/common.c:218
 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x4d6ad6
Code: 00 00 00 90 31 c9 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 49 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 90 48 83 ec 28 89 54 24 14 48 89 74 24
RSP: 002b:00007ffecbf8c5f8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: 00000000000013d9 RBX: 0000000000000000 RCX: 00000000004d6ad6
RDX: 0000000040000000 RSI: 00007ffecbf8c61c RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000017 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000207773f0
R13: 00007ffecbf8c61c R14: 0000000020772b90 R15: 000000000063f160
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.166 msecs