INFO: task segctord:10175 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:segctord        state:D stack:28680 pid:10175 tgid:10175 ppid:2      task_flags:0x200040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x16e2/0x53f0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x896/0x1040
 down_write+0x1bc/0x200
 nilfs_transaction_lock+0x24a/0x4b0
 nilfs_segctor_thread+0x6be/0xdb0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75d000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u10:1/36:
2 locks held by getty/5419:
 #0: ffff88816e3e10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x13a0
2 locks held by syz.0.1754/10174:
1 lock held by segctord/10175:
 #0: ffff8881a61c32a0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_lock+0x24a/0x4b0
3 locks held by kworker/0:5/12402:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9bd/0x1470
 #1: ffffc900064bfc40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9bd/0x1470
 #2: ffff88816be43a80 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_damage_work+0x11b/0x720
10 locks held by syz.8.4403/16727:
8 locks held by syz-executor/17439:

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf9e/0xff0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 17439 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:unwind_next_frame+0x3b/0x2380
Code: 70 49 89 fe 49 bc 00 00 00 00 00 fc ff df 48 83 c7 48 48 89 f8 48 c1 e8 03 48 89 44 24 20 42 80 3c 20 00 74 05 e8 65 84 b8 00 <49> 8b 5e 48 49 8d 7e 38 49 89 fd 49 c1 ed 03 43 80 7c 25 00 00 74
RSP: 0018:ffffc9000888eb00 EFLAGS: 00000246
RAX: 1ffff92001111d7e RBX: ffffc9000888ec60 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8185a1b6 RDI: ffffc9000888ebf0
RBP: ffffc9000888ec30 R08: ffffc9000888ec70 R09: 000000000000000d
R10: ffffc9000888ebf8 R11: ffffffff81b02570 R12: dffffc0000000000
R13: 1ffff11023a4546e R14: ffffc9000888eba8 R15: ffffc9000888eba8
FS:  000055558e701500(0000) GS:ffff88818de52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000010a4cc000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 save_stack+0x122/0x230
 __set_page_owner+0x8d/0x4c0
 post_alloc_hook+0x231/0x280
 get_page_from_freelist+0x2503/0x25a0
 __alloc_frozen_pages_noprof+0x18d/0x380
 alloc_pages_mpol+0x22b/0x390
 alloc_pages_noprof+0xa8/0x190
 pte_alloc_one+0x23/0x370
 __pte_alloc+0x25/0x420
 copy_pmd_range+0x78cd/0x8140
 copy_page_range+0xbe9/0x1210
 dup_mmap+0xf09/0x1d70
 copy_mm+0x136/0x4a0
 copy_process+0x18bd/0x3d00
 kernel_clone+0x248/0x8e0
 __x64_sys_clone+0x1b6/0x230
 do_syscall_64+0x170/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0ac5c6a92
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffdb0493710 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffdb0493710 RCX: 00007fb0ac5c6a92
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffdb049389c R08: 0000000000000000 R09: 0000000000000001
R10: 000055558e7017d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000081200 R15: 00007ffdb04938f0
 </TASK>
