syzbot

INFO: task syz-executor120:5838 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc7-syzkaller-00069-g81e4f8d68c66 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor120 state:D stack:23840 pid:5838  tgid:5838  ppid:5835   task_flags:0x400100 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75
 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+0x1a1/0x640 kernel/kthread.c:791
 bch2_copygc_stop+0x4f/0x150 fs/bcachefs/movinggc.c:413
 __bch2_fs_read_only+0x47/0x450 fs/bcachefs/super.c:265
 bch2_fs_read_only+0xbff/0x12a0 fs/bcachefs/super.c:356
 __bch2_fs_stop+0x105/0x5c0 fs/bcachefs/super.c:634
 generic_shutdown_super+0x139/0x2d0 fs/super.c:642
 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2312
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1413
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 ptrace_notify+0x2d9/0x380 kernel/signal.c:2522
 ptrace_report_syscall include/linux/ptrace.h:415 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
 syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173
 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
 syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd6d308e3c7
RSP: 002b:00007ffd102d2f08 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fd6d308e3c7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd102d2fc0
RBP: 00007ffd102d2fc0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffd102d4030
R13: 00005555647116c0 R14: 0000000000000001 R15: 431bde82d7b634db
 </TASK>
INFO: task bch-copygc/loop:5849 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc7-syzkaller-00069-g81e4f8d68c66 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-copygc/loop state:D stack:19696 pid:5849  tgid:5849  ppid:2      task_flags:0x240040 flags:0x00024000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 __closure_sync+0x259/0x2f0 lib/closure.c:146
 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:237 [inline]
 __bch2_write+0x5376/0x5a80 fs/bcachefs/io_write.c:1530
 bch2_write+0x865/0x1660 fs/bcachefs/io_write.c:1659
 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:439
 move_write fs/bcachefs/move.c:135 [inline]
 bch2_moving_ctxt_do_pending_writes+0x44c/0x8d0 fs/bcachefs/move.c:166
 bch2_move_ratelimit+0x76c/0xeb0 fs/bcachefs/move.c:512
 bch2_evacuate_bucket+0xfe9/0x3280 fs/bcachefs/move.c:747
 bch2_copygc+0x415d/0x4fa0 fs/bcachefs/movinggc.c:240
 bch2_copygc_thread+0x6ef/0xba0 fs/bcachefs/movinggc.c:383
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 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/31:
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
3 locks held by kworker/u8:7/3466:
 #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc9000c9afc60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000c9afc60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8e9d5290 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_disable+0x12/0x20 kernel/jump_label.c:247
2 locks held by getty/5579:
 #0: ffff88803269b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
2 locks held by syz-executor120/5838:
 #0: ffff88807aa0e0e0 (&type->s_umount_key#43){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88807aa0e0e0 (&type->s_umount_key#43){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88807aa0e0e0 (&type->s_umount_key#43){+.+.}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505
 #1: ffff888074480278 (&c->state_lock){+.+.}-{4:4}, at: __bch2_fs_stop+0xfd/0x5c0 fs/bcachefs/super.c:633

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc7-syzkaller-00069-g81e4f8d68c66 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111