INFO: task syz-executor:5837 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20696 pid:5837  tgid:5837  ppid:1      task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_timeout+0x9a/0x270 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+0x2bf/0x5d0 kernel/sched/completion.c:148
 kthread_stop+0x194/0x5f0 kernel/kthread.c:791
 bch2_copygc_stop+0x4f/0x150 fs/bcachefs/movinggc.c:438
 __bch2_fs_read_only+0x47/0x5b0 fs/bcachefs/super.c:280
 bch2_fs_read_only+0x42a/0xb00 fs/bcachefs/super.c:366
 __bch2_fs_stop+0x100/0x900 fs/bcachefs/super.c:677
 generic_shutdown_super+0x132/0x2c0 fs/super.c:643
 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618
 deactivate_locked_super+0xbc/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3ef3d8fc57
RSP: 002b:00007ffe17a36f98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3ef3e10925 RCX: 00007f3ef3d8fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe17a37050
RBP: 00007ffe17a37050 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe17a380e0
R13: 00007f3ef3e10925 R14: 00000000000248ce R15: 00007ffe17a38120
 </TASK>
INFO: task bch-reclaim/loo:6695 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-reclaim/loo state:D stack:26696 pid:6695  tgid:6695  ppid:2      task_flags:0x200840 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
 btree_write_buffer_flush_seq+0x18bd/0x1a40 fs/bcachefs/btree_write_buffer.c:571
 bch2_btree_write_buffer_journal_flush+0x69/0xb0 fs/bcachefs/btree_write_buffer.c:588
 journal_flush_pins+0x8e0/0xe90 fs/bcachefs/journal_reclaim.c:604
 __bch2_journal_reclaim+0x8e9/0xea0 fs/bcachefs/journal_reclaim.c:732
 bch2_journal_reclaim_thread+0x177/0x4f0 fs/bcachefs/journal_reclaim.c:774
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/1:1/43:
2 locks held by getty/5593:
 #0: ffff88814dc180a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/5837:
 #0: ffff8880796cc0e0 (&type->s_umount_key#64){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880796cc0e0 (&type->s_umount_key#64){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880796cc0e0 (&type->s_umount_key#64){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffff888053a00278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:676
3 locks held by bch-reclaim/loo/6695:
 #0: ffff888053a4af68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:773
 #1: ffff888053a04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #1: ffff888053a04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #1: ffff888053a04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7f4/0xd80 fs/bcachefs/btree_iter.c:3505
 #2: ffff888053a04740 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x18bd/0x1a40 fs/bcachefs/btree_write_buffer.c:571
3 locks held by bch-copygc/loop/6696:
 #0: ffff888053a04740 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x18bd/0x1a40 fs/bcachefs/btree_write_buffer.c:571
 #1: ffff888053a04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #1: ffff888053a04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #1: ffff888053a04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3299
 #2: ffff888053a26710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1211
1 lock held by syz.7.275/8217:
 #0: ffff8880796cc0e0 (&type->s_umount_key#64){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff8880796cc0e0 (&type->s_umount_key#64){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz-executor/8512:
 #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5206 Comm: udevd Not tainted 6.16.0-rc6-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:rw_verify_area+0x0/0x650 fs/read_write.c:452
Code: f7 4c 89 fe 4c 89 e2 4c 89 e9 5b 41 5c 41 5d 41 5e 41 5f 5d e9 81 fc ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 49 89 ce 49
RSP: 0018:ffffc90003bafc98 EFLAGS: 00000246
RAX: ffffffff82318bbb RBX: 00007ffffffff000 RCX: 0000000000000110
RDX: ffffc90003bafe60 RSI: ffff888032d10c40 RDI: 0000000000000000
RBP: ffffc90003bafe10 R08: ffff888034ae3843 R09: 1ffff1100695c708
R10: dffffc0000000000 R11: ffffed100695c709 R12: 00007ffdd37f9220
R13: 0000000000000110 R14: 1ffff92000775fa0 R15: ffff888032d10c40
FS:  00007fc50c357880(0000) GS:ffff888125d4f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5a14f81ab8 CR3: 0000000032f00000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 vfs_read+0x154/0x980 fs/read_write.c:563
 ksys_read+0x145/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc50bca7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffdd37f8fe0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fc50c357880 RCX: 00007fc50bca7407
RDX: 0000000000000110 RSI: 00007ffdd37f9220 RDI: 0000000000000007
RBP: 00000000000000cf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000564276bda100 R14: 00005642b0a10930 R15: 00007ffdd37f9220
 </TASK>