INFO: task kworker/u8:7:2478 blocked for more than 143 seconds.
      Not tainted 6.9.0-syzkaller-10729-gb6394d6f7159 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7    state:D stack:13528 pid:2478  tgid:2478  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-bcachefs-1)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6745
 __schedule_loop kernel/sched/core.c:6822 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6837
 __closure_sync+0x259/0x2f0 lib/closure.c:135
 closure_sync include/linux/closure.h:194 [inline]
 __bch2_write+0x54a5/0x5c40 fs/bcachefs/io_write.c:1495
 bch2_write+0x947/0x1670 fs/bcachefs/io_write.c:1623
 closure_queue include/linux/closure.h:269 [inline]
 closure_call include/linux/closure.h:402 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:460 [inline]
 __bch2_writepage+0x1416/0x2b50 fs/bcachefs/fs-io-buffered.c:607
 write_cache_pages+0xd0/0x230 mm/page-writeback.c:2591
 bch2_writepages+0x14f/0x380 fs/bcachefs/fs-io-buffered.c:650
 do_writepages+0x359/0x870 mm/page-writeback.c:2634
 __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1651
 writeback_sb_inodes+0x99c/0x1380 fs/fs-writeback.c:1947
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2018
 wb_writeback+0x495/0xd40 fs/fs-writeback.c:2129
 wb_check_background_flush fs/fs-writeback.c:2199 [inline]
 wb_do_writeback fs/fs-writeback.c:2287 [inline]
 wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2314
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
 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
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
3 locks held by kworker/u8:7/2478:
 #0: ffff88801b694148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88801b694148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90009c3fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90009c3fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff8880720120e0 (&type->s_umount_key#44){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562
2 locks held by getty/4839:
 #0: ffff88802ae4d0a0 (&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
3 locks held by syz-executor384/5407:

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

NMI backtrace for cpu 1
CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.9.0-syzkaller-10729-gb6394d6f7159 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
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:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4515 Comm: syslogd Not tainted 6.9.0-syzkaller-10729-gb6394d6f7159 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:check_preemption_disabled+0x60/0x120 lib/smp_processor_id.c:19
Code: 00 48 3b 44 24 08 0f 85 ce 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 cc cc cc cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 74 c5 49 89 f6 49 89 ff 65 4c 8b 24 25 c0 d4
RSP: 0018:ffffc9000d7ff6e0 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffff88803026da00
RDX: ffff88803026da00 RSI: ffffffff8bcac560 RDI: ffffffff8c1f0d80
RBP: dffffc0000000000 R08: ffffffff8b7ad7f7 R09: 1ffffffff25ef4b0
R10: dffffc0000000000 R11: fffffbfff25ef4b1 R12: 0000000000000246
R13: ffff88803026da00 R14: 00000000ffffffff R15: ffff88802a62f9e8
FS:  00007fa073389380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f77fc3ff000 CR3: 000000007de86000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
 lock_is_held_type+0x7b/0x190 kernel/locking/lockdep.c:5824
 lock_is_held include/linux/lockdep.h:231 [inline]
 xa_entry include/linux/xarray.h:1220 [inline]
 xas_descend lib/xarray.c:207 [inline]
 xas_load+0x19c/0x5c0 lib/xarray.c:245
 filemap_get_entry+0x1fe/0x4e0 mm/filemap.c:1840
 shmem_get_folio_gfp+0x2a8/0x1f50 mm/shmem.c:1982
 shmem_get_folio mm/shmem.c:2160 [inline]
 shmem_write_begin+0x170/0x4d0 mm/shmem.c:2743
 generic_perform_write+0x322/0x640 mm/filemap.c:4015
 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2919
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa72/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa0734ddbf2
Code: 89 c7 48 89 44 24 08 e8 7b 34 fa ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6f 48 8b 15 07 a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff717c2e38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fa0734ddbf2
RDX: 000000000000009d RSI: 000055be972fbc50 RDI: 0000000000000003
RBP: 000055be972fbc50 R08: 0000000000000001 R09: 0000000000000000
R10: 00007fa07367c3a3 R11: 0000000000000246 R12: 000000000000009d
R13: 00007fa073389300 R14: 0000000000000004 R15: 000055be972fba60
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.781 msecs