INFO: task kworker/u9:1:32 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:1    state:D stack:20168 pid:32    tgid:32    ppid:2      task_flags:0x4248160 flags:0x00004000
Workqueue: writeback wb_workfn (flush-bcachefs-36)
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 __closure_sync_timeout+0x282/0x3a0
 __bch2_wait_on_allocator+0x112/0x240
 __bch2_write+0x31ef/0x3900
 __bch2_writepage+0x1536/0x2790
 write_cache_pages+0x64/0x100
 bch2_writepages+0xf9/0x2d0
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x145/0xff0
 writeback_sb_inodes+0x6c7/0x1010
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x44f/0xaf0
 wb_workfn+0xaef/0xef0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.1.216:7524 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.216       state:D stack:17448 pid:7524  tgid:7523  ppid:5848   task_flags:0x440140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 __closure_sync_timeout+0x282/0x3a0
 __bch2_wait_on_allocator+0x112/0x240
 __bch2_write+0x31ef/0x3900
 __bch2_writepage+0x1536/0x2790
 write_cache_pages+0x64/0x100
 bch2_writepages+0xf9/0x2d0
 do_writepages+0x32e/0x550
 file_write_and_wait_range+0x23e/0x340
 bch2_fsync+0x127/0x330
 bch2_write_iter+0x2822/0x2b90
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f611f38ebe9
RSP: 002b:00007f6120193038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f611f5c5fa0 RCX: 00007f611f38ebe9
RDX: 00000000ffffffc1 RSI: 0000200000000200 RDI: 0000000000000007
RBP: 00007f611f411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f611f5c6038 R14: 00007f611f5c5fa0 R15: 00007ffe41351478
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u9:1/32:
 #0: ffff88801a506948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000065fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888041b9a0e0 (&type->s_umount_key#62){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5677:
 #0: ffff888107df10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz.1.216/7524:
 #0: ffff88810c92f2f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320
 #1: ffff888041b9a428 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x211/0xb30

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:handle_softirqs+0x793/0x870
Code: c7 04 30 00 00 00 00 65 48 8b 05 78 8e 1b 11 48 3b 84 24 c0 00 00 00 0f 85 c7 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f <5d> e9 57 b9 f7 09 cc 90 0f 0b 90 eb 90 90 0f 0b 90 e9 51 ff ff ff
RSP: 0018:ffffc90000007f50 EFLAGS: 00000046
RAX: 6b4b651b8e8ae000 RBX: ffffffff8de95100 RCX: 0000000004200002
RDX: 0000000000000100 RSI: ffffffff8dba7696 RDI: ffffffff8be33880
RBP: ffffc90000007f50 R08: ffffffff8fa39037 R09: 1ffffffff1f47206
R10: dffffc0000000000 R11: fffffbfff1f47207 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000000fec R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb8b6774c40 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_call_function_single+0xa3/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20
RIP: 0010:pv_native_safe_halt+0x13/0x20
Code: 53 e7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 73 67 0e 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 00000282
RAX: 6b4b651b8e8ae000 RBX: ffffffff819683c8 RCX: 6b4b651b8e8ae000
RDX: 0000000000000001 RSI: ffffffff8d9b8241 RDI: ffffffff8be33880
RBP: ffffffff8de07eb8 R08: ffff88804b032f9b R09: 1ffff110096065f3
R10: dffffc0000000000 R11: ffffed10096065f4 R12: ffffffff8fa39030
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a20
 default_idle+0x13/0x20
 default_idle_call+0x74/0xb0
 do_idle+0x1e8/0x510
 cpu_startup_entry+0x44/0x60
 rest_init+0x2de/0x300
 start_kernel+0x3a9/0x410
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x143/0x1c0
 common_startup_64+0x13e/0x147
 </TASK>
