INFO: task syz.0.16:5490 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16        state:D stack:19784 pid:5490  tgid:5489  ppid:5453   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 __closure_sync+0x163/0x220 lib/closure.c:146
 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:315 [inline]
 bch2_btree_update_start+0x18dc/0x1de0 fs/bcachefs/btree_update_interior.c:1293
 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1921
 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:914
 __bch2_trans_commit+0x1bb5/0x8870 fs/bcachefs/btree_trans_commit.c:1104
 bch2_trans_commit fs/bcachefs/btree_update.h:241 [inline]
 bch2_logged_op_start+0x177/0x290 fs/bcachefs/logged_ops.c:93
 bch2_truncate+0x128/0x200 fs/bcachefs/io_misc.c:324
 bchfs_truncate+0x8b1/0xc20 fs/bcachefs/fs-io.c:511
 notify_change+0xb36/0xe40 fs/attr.c:552
 do_truncate+0x1a4/0x220 fs/open.c:68
 handle_truncate fs/namei.c:3517 [inline]
 do_open fs/namei.c:3900 [inline]
 path_openat+0x306c/0x3830 fs/namei.c:4055
 do_filp_open+0x1fa/0x410 fs/namei.c:4082
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 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: 0033:0x7fd35658e929
RSP: 002b:00007fd357460038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd3567b5fa0 RCX: 00007fd35658e929
RDX: 0000000000068342 RSI: 0000200000000280 RDI: ffffffffffffff9c
RBP: 00007fd356610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000020 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd3567b5fa0 R15: 00007ffceaf8c388
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8e13f0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13f0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13f0a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5128:
 #0: ffff8880367a90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by syz.0.16/5490:
 #0: ffff88801eddc428 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff88801fcdc8e0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:874 [inline]
 #1: ffff88801fcdc8e0 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
 #2: ffff88804f080a50 (&c->snapshot_create_lock){.+.+}-{4:4}, at: bch2_truncate+0xeb/0x200 fs/bcachefs/io_misc.c:322
 #3: ffff88804f084398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #3: ffff88804f084398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #3: ffff88804f084398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7f4/0xd80 fs/bcachefs/btree_iter.c:3505
 #4: ffff88804f0a6710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1211
3 locks held by syz.1.656/6914:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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+0x70e/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>