syzbot

INFO: task bch-reclaim/loo:5228 blocked for more than 143 seconds.
      Not tainted 6.11.0-syzkaller-11993-g3efc57369a0c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-reclaim/loo state:D stack:26528 pid:5228  tgid:5228  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5315 [inline]
 __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675
 __schedule_loop kernel/sched/core.c:6752 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6767
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:739
 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:6701
2 locks held by getty/4978:
 #0: ffff88802f88b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
5 locks held by syz-executor249/5218:
1 lock held by bch-reclaim/loo/5228:
 #0: ffff8880774cb0a8 (&j->reclaim_lock){+.+.}-{3:3}, at: bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:739

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-11993-g3efc57369a0c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5218 Comm: syz-executor249 Not tainted 6.11.0-syzkaller-11993-g3efc57369a0c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x35/0x90 kernel/kcov.c:294
Code: 0c 25 80 d7 03 00 65 8b 05 40 ef 6e 7e 25 00 01 ff 00 74 10 3d 00 01 00 00 75 57 83 b9 1c 16 00 00 00 74 4e 8b 81 f8 15 00 00 <83> f8 03 75 43 48 8b 91 00 16 00 00 44 8b 89 fc 15 00 00 49 c1 e1
RSP: 0018:ffffc90003b26dd8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880614000c0 RCX: ffff88802b6ebc00
RDX: 0000000000000000 RSI: 0000000406000008 RDI: 0000000d06000009
RBP: ffffc90003b26f30 R08: ffffffff842102c8 R09: 0000000000000000
R10: 0000000000000000 R11: 1400000000000000 R12: dffffc0000000000
R13: 0000000000000008 R14: 0000000d06000009 R15: 0000000406000008
FS:  0000555592158380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558d3ae2e600 CR3: 0000000078452000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __wb_key_ref_cmp fs/bcachefs/btree_write_buffer.c:28 [inline]
 wb_key_ref_cmp fs/bcachefs/btree_write_buffer.c:46 [inline]
 wb_sort+0x588/0x720 fs/bcachefs/btree_write_buffer.c:107
 bch2_btree_write_buffer_flush_locked+0x48a/0x59f0 fs/bcachefs/btree_write_buffer.c:308
 btree_write_buffer_flush_seq+0x1a43/0x1bc0 fs/bcachefs/btree_write_buffer.c:510
 bch2_btree_write_buffer_journal_flush+0x4e/0x80 fs/bcachefs/btree_write_buffer.c:525
 journal_flush_pins+0x5f7/0xb20 fs/bcachefs/journal_reclaim.c:565
 journal_flush_done+0x8e/0x260 fs/bcachefs/journal_reclaim.c:819
 bch2_journal_flush_pins+0x102/0x3a0 fs/bcachefs/journal_reclaim.c:852
 bch2_journal_flush_all_pins fs/bcachefs/journal_reclaim.h:76 [inline]
 __bch2_fs_read_only+0x124/0x430 fs/bcachefs/super.c:274
 bch2_fs_read_only+0xb57/0x1200 fs/bcachefs/super.c:354
 __bch2_fs_stop+0x105/0x540 fs/bcachefs/super.c:619
 generic_shutdown_super+0x139/0x2d0 fs/super.c:642
 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2179
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
 task_work_run+0x24f/0x310 kernel/task_work.c:228
 ptrace_notify+0x2d2/0x380 kernel/signal.c:2403
 ptrace_report_syscall include/linux/ptrace.h:415 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
 syscall_exit_work+0xc6/0x190 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+0x279/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc4f73d547
Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe9220f5b8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fdc4f73d547
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe9220f670
RBP: 00007ffe9220f670 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffe922106e0
R13: 00005555921596c0 R14: 431bde82d7b634db R15: 00007ffe92210700
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.359 msecs