INFO: task syz.4.193:7483 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.193       state:D stack:16232 pid:7483  tgid:7482  ppid:6123   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 bch2_direct_write+0x192/0x2ce0
 bch2_write_iter+0x18f/0x2b90
 iter_file_splice_write+0x975/0x10e0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x5a8/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcda678ebe9
RSP: 002b:00007fcda76df038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fcda69b5fa0 RCX: 00007fcda678ebe9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007fcda6811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000ff7e82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcda69b6038 R14: 00007fcda69b5fa0 R15: 00007ffd6d40c468
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/u10:0/27:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5673:
 #0: ffff8880226b10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz.4.193/7483:
 #0: ffff888024220428 (sb_writers#18){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160
 #1: ffff888113d4f330 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: bch2_direct_write+0x192/0x2ce0
4 locks held by syz.4.193/7505:
 #0: ffff888024220428 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888113d4f330 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: do_truncate+0x171/0x220
 #2: ffff888117980a50 (&c->snapshot_create_lock){.+.+}-{4:4}, at: bch2_truncate+0xeb/0x200
 #3: 
ffff8881179cb0d8 (&j->discard_lock){+.+.}-{4:4}, at: bch2_journal_do_discards+0x42/0xb40
1 lock held by syz.6.431/12579:
 #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
5 locks held by syz.6.431/12582:
1 lock held by syz.5.436/12623:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12623 Comm: syz.5.436 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:io_serial_out+0x7c/0xc0
Code: 77 70 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bc e5 d3 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 17 57 2d 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90003516d10 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000040006 RDI: 0000000000040007
RBP: 00000000000003f9 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff854f3380 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99def420 R15: 0000000000000000
FS:  00007f9909f956c0(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f9ddff8 CR3: 00000000281f4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0x5f2/0x1ba0
 console_flush_all+0x728/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 __bch2_print+0x176/0x220
 bch2_fs_recovery+0x2067/0x3a50
 bch2_fs_start+0xaaf/0xda0
 bch2_fs_get_tree+0xb39/0x1520
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f990919038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9909f94e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9909f94ef0 RCX: 00007f990919038a
RDX: 0000200000000040 RSI: 0000200000000000 RDI: 00007f9909f94eb0
RBP: 0000200000000040 R08: 00007f9909f94ef0 R09: 0000000000004000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000200000000000
R13: 00007f9909f94eb0 R14: 0000000000005939 R15: 00002000000000c0
 </TASK>
