INFO: task syz.7.93:6715 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.93        state:D stack:22856 pid:6715  tgid:6714  ppid:6131   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x9a/0x270
 wait_for_completion+0x2bf/0x5d0
 f2fs_issue_checkpoint+0x382/0x610
 f2fs_unlink+0x5eb/0xac0
 vfs_unlink+0x394/0x650
 do_unlinkat+0x345/0x560
 __x64_sys_unlinkat+0xd3/0xf0
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc6e018eec9
RSP: 002b:00007fc6e0f55038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007fc6e03e5fa0 RCX: 00007fc6e018eec9
RDX: 0000000000000000 RSI: 0000200000000380 RDI: ffffffffffffff9c
RBP: 00007fc6e0211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc6e03e6038 R14: 00007fc6e03e5fa0 R15: 00007ffc73d7f078
 </TASK>
INFO: task syz.7.93:6720 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.93        state:D stack:24648 pid:6720  tgid:6714  ppid:6131   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 path_openat+0x8da/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc6e018eec9
RSP: 002b:00007fc6de3f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc6e03e6090 RCX: 00007fc6e018eec9
RDX: 00000000000026e1 RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007fc6e0211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc6e03e6128 R14: 00007fc6e03e6090 R15: 00007ffc73d7f078
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by syslogd/5243:
 #0: ffff88823c63a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88823c624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
2 locks held by getty/5641:
 #0: ffff888170b6a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by udevd/5813:
3 locks held by syz.7.93/6715:
 #0: ffff8881141e2420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff8881bb75b718 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: do_unlinkat+0x1c7/0x560
 #2: ffff888113045200 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: vfs_unlink+0xf2/0x650
2 locks held by syz.7.93/6720:
 #0: ffff8881141e2420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff8881bb75b718 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: path_openat+0x8da/0x3830
1 lock held by syz.7.93/6721:
4 locks held by f2fs_ckpt-7:7/6716:
1 lock held by syz.7.327/8970:
 #0: ffff8881141e20e0 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x25c/0x3b0
1 lock held by syz.2.338/9162:
 #0: ffff8881141e20e0 (&type->s_umount_key#82){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/9250:
1 lock held by syz-executor/9549:
3 locks held by syz-executor/9850:
 #0: ffff8881a6228420 (sb_writers#4){++++}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff8881a8a620c0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: ext4_readdir+0x1ab6/0x3b60
 #2: ffff88823c63a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140

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

NMI backtrace for cpu 0
CPU: 0 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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9850 Comm: syz-executor 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:rcu_is_watching+0x74/0xb0
Code: 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d e9 31 eb 10 74 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f <e9> 47 66 a8 09 cc e8 01 9a 8d ff eb e8 48 c7 c7 00 30 14 8e 48 89
RSP: 0018:ffffc900055e7308 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff903b0001 RCX: 1d19a1c820c4a600
RDX: ffffc900055e7401 RSI: ffffffff8bc078c0 RDI: ffffffff8bc07880
RBP: dffffc0000000000 R08: ffffc900055e7e80 R09: 0000000000000000
R10: ffffc900055e7498 R11: fffff52000abce95 R12: ffffc900055e7e90
R13: ffffffff81731d25 R14: ffffffff8e13d320 R15: ffffffff81731d25
FS:  0000555587130500(0000) GS:ffff8882a9d0f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4a489b4198 CR3: 000000011cd48000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_release+0x4b/0x3e0
 unwind_next_frame+0x19a9/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x3d5/0x6f0
 ext4_dir_open+0x4f/0xa0
 do_dentry_open+0x953/0x13f0
 vfs_open+0x3b/0x340
 path_openat+0x2ee5/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f073eb8e7c1
Code: 44 24 18 31 c0 41 83 e2 40 75 3e 89 f0 25 00 00 41 00 3d 00 00 41 00 74 30 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 3f 48 8b 54 24 18 64 48 2b 14 25 28 00 00 00
RSP: 002b:00007ffe0d70a040 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f073ec11d7d RCX: 00007f073eb8e7c1
RDX: 0000000000090800 RSI: 00007ffe0d70b250 RDI: 00000000ffffff9c
RBP: 00007f073ec11d7d R08: 000055558715366b R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffe0d70b250
R13: 00007f073ec11d7d R14: 00005555871304a8 R15: 00007ffe0d70d410
 </TASK>
