syzbot

INFO: task bch-copygc/loop:5858 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-copygc/loop state:D stack:20112 pid:5858  tgid:5858  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615
 __closure_sync_timeout+0x2d8/0x450 lib/closure.c:217
 closure_sync_timeout include/linux/closure.h:206 [inline]
 __bch2_wait_on_allocator+0x11a/0x250 fs/bcachefs/alloc_foreground.c:1812
 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:239 [inline]
 __bch2_write+0x562a/0x5dd0 fs/bcachefs/io_write.c:1504
 bch2_write+0x9b5/0x1760 fs/bcachefs/io_write.c:1634
 closure_queue include/linux/closure.h:270 [inline]
 closure_call include/linux/closure.h:432 [inline]
 bch2_data_update_read_done+0x22e/0x330 fs/bcachefs/data_update.c:426
 move_write fs/bcachefs/move.c:133 [inline]
 bch2_moving_ctxt_do_pending_writes+0x44c/0x8d0 fs/bcachefs/move.c:164
 bch2_move_ratelimit+0x76c/0xeb0 fs/bcachefs/move.c:492
 bch2_evacuate_bucket+0x26b3/0x3620 fs/bcachefs/move.c:702
 bch2_copygc+0x42c9/0x4ca0 fs/bcachefs/movinggc.c:240
 bch2_copygc_thread+0x737/0xc20 fs/bcachefs/movinggc.c:381
 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: 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:6720
2 locks held by getty/5592:
 #0: ffff8880310540a0 (&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-executor800/6206:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5190 Comm: klogd Not tainted 6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0033:0x7f5bf48ea500
Code: fc ff ff 45 85 db 74 22 eb cd 4c 89 c0 48 c1 e8 0c 49 33 00 48 89 04 d7 66 42 ff 0c 6f 49 c7 40 08 00 00 00 00 e9 16 04 00 00 <48> 81 fb ff 03 00 00 0f 86 9c 00 00 00 43 8d 44 24 fe 48 8d 44 c5
RSP: 002b:00007ffcb47918d0 EFLAGS: 00000246
RAX: 671de4c05b4bf30d RBX: 0000000000002010 RCX: 0000000000000000
RDX: 00007f5bf4a13b00 RSI: 0000000000000000 RDI: 0000564e23958010
RBP: 00007f5bf4a13aa0 R08: 0000000000000004 R09: 0000000000000000
R10: 000000000000020f R11: 0000000000000000 R12: 000000000000006b
R13: 00000000000001ff R14: 00007f5bf4a13b00 R15: 0000000000000000
FS:  00007f5bf47e4380 GS:  0000000000000000