INFO: task blkid:5912 blocked for more than 120 seconds.
      Not tainted 4.9.82-gcdfc8df #45
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D26816  5912   2142 0x00000004
 ffff8801c0948000 0000000000000000 ffff8801cbbd24c0 ffff8801d9b73000
 ffff8801db321b98 ffff8801c09ff4e0 ffffffff838a3e0b 0000000041b58ab3
 ffffffff841937f8 00ffffff8123c030 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a53af>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838b150c>] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768
 [<ffffffff838a35be>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5172
 [<ffffffff838a6829>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff838a6829>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff838a6092>] __wait_on_bit_lock+0xc2/0x1c0 kernel/sched/wait.c:421
 [<ffffffff81432f5f>] __lock_page+0xff/0x160 mm/filemap.c:934
 [<ffffffff8145d5d3>] lock_page include/linux/pagemap.h:454 [inline]
 [<ffffffff8145d5d3>] write_cache_pages+0x833/0xec0 mm/page-writeback.c:2214
 [<ffffffff8145dd3a>] generic_writepages+0xda/0x150 mm/page-writeback.c:2333
 [<ffffffff8162b61d>] blkdev_writepages+0x1d/0x30 fs/block_dev.c:1764
 [<ffffffff8145f93d>] do_writepages+0xed/0x1c0 mm/page-writeback.c:2347
 [<ffffffff8143b4e3>] __filemap_fdatawrite_range+0x1b3/0x250 mm/filemap.c:390
 [<ffffffff8143b611>] __filemap_fdatawrite mm/filemap.c:398 [inline]
 [<ffffffff8143b611>] filemap_fdatawrite mm/filemap.c:403 [inline]
 [<ffffffff8143b611>] filemap_write_and_wait+0x61/0x120 mm/filemap.c:543
 [<ffffffff8162d860>] __sync_blockdev fs/block_dev.c:194 [inline]
 [<ffffffff8162d860>] sync_blockdev.part.28+0x50/0x70 fs/block_dev.c:203
 [<ffffffff8162de84>] sync_blockdev fs/block_dev.c:190 [inline]
 [<ffffffff8162de84>] __blkdev_put+0x184/0x7e0 fs/block_dev.c:1585
 [<ffffffff8162f2b5>] blkdev_put+0x85/0x550 fs/block_dev.c:1663
 [<ffffffff8162f80b>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1670
 [<ffffffff8157580c>] __fput+0x28c/0x6e0 fs/file_table.c:208
 [<ffffffff81575ce5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff81195855>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff81003a4c>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff81003a4c>] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161
 [<ffffffff810066d0>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff810066d0>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff810066d0>] do_syscall_64+0x370/0x490 arch/x86/entry/common.c:287
 [<ffffffff838b4e7d>] entry_SYSCALL_64_after_swapgs+0x47/0xc5

Showing all locks held in the system:
3 locks held by kworker/u4:1/22:
 #0:  ("writeback"){++++.+}, at: [<ffffffff811897b2>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("writeback"){++++.+}, at: [<ffffffff811897b2>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("writeback"){++++.+}, at: [<ffffffff811897b2>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("writeback"){++++.+}, at: [<ffffffff811897b2>] process_one_work+0x6f2/0x1610 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff811897ec>] process_one_work+0x72c/0x1610 kernel/workqueue.c:2089
 #2:  (&type->s_umount_key#22){.+.+..}, at: [<ffffffff81579d10>] trylock_super+0x20/0x100 fs/super.c:393
2 locks held by khungtaskd/515:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81373095>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81373095>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81238190>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3469:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d3c3f>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3597:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b3082>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8200a424>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by blkid/5912:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162ddbc>] __blkdev_put+0xbc/0x7e0 fs/block_dev.c:1579
1 lock held by syz-executor1/5920:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81631698>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:1976

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

NMI backtrace for cpu 0
CPU: 0 PID: 515 Comm: khungtaskd Not tainted 4.9.82-gcdfc8df #45
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d871fd00 ffffffff81d94fc9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810bb190 ffff8801d871fd38
 ffffffff81da00ed 0000000000000000 0000000000000000 ffff8801c0948418
Call Trace:
 [<ffffffff81d94fc9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94fc9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da00ed>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0227>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bb284>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81373660>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81373660>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81373660>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81373660>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119a7bd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b500c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:361
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.82-gcdfc8df #45
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9b73000 task.stack: ffff8801d9b88000
RIP: 0010:[<ffffffff8123a498>] 
c [<ffffffff8123a498>] mark_lock+0xf8/0xfd0 kernel/locking/lockdep.c:3039
RSP: 0018:ffff8801db307ca0  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000001000 RCX: 1ffff1003b36e71a
RDX: 1ffffffff0a6c194 RSI: ffff8801d9b738b0 RDI: ffffffff85360ca0
RBP: ffff8801db307ce0 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8801d9b73000 R12: ffffffff85360c70
R13: 000000000000000c R14: ffff8801d9b738d0 R15: ffff8801d9b738b0
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f87fffda9b8 CR3: 00000001c6f6e000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000248
c ffff8801c6805140
c ffff8801d9b73000
c ffff8801d9b738b0
c
 000000000000002e
c 0000000000000000
c 0000000000000000
c 0000000000000000
c
 ffff8801db307eb0
c ffffffff8123c659
c ffffffff8123c030
c ffffffff838b46c5
c
Call Trace:
 <IRQ> 
d [<ffffffff8123c659>] __lock_acquire+0x629/0x3640 kernel/locking/lockdep.c:3306
 [<ffffffff812400ae>] lock_acquire+0x12e/0x410 kernel/locking/lockdep.c:3756
 [<ffffffff812c2fb6>] seqcount_lockdep_reader_access include/linux/seqlock.h:80 [inline]
 [<ffffffff812c2fb6>] read_seqcount_begin include/linux/seqlock.h:163 [inline]
 [<ffffffff812c2fb6>] ktime_get+0x76/0x1d0 kernel/time/timekeeping.c:757
 [<ffffffff812daba3>] tick_nohz_irq_enter kernel/time/tick-sched.c:1144 [inline]
 [<ffffffff812daba3>] tick_irq_enter+0xe3/0x220 kernel/time/tick-sched.c:1165
 [<ffffffff81146ac3>] irq_enter+0xb3/0xd0 kernel/softirq.c:345
 [<ffffffff838b94ca>] smp_reschedule_interrupt+0xa/0x80 arch/x86/kernel/smp.c:264
 [<ffffffff838b7140>] reschedule_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:659
 <EOI> 
d [<ffffffff838b3af6>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
 [<ffffffff838b3125>] arch_safe_halt arch/x86/include/asm/paravirt.h:103 [inline]
 [<ffffffff838b3125>] default_idle+0x55/0x360 arch/x86/kernel/process.c:295
 [<ffffffff8106bc3a>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:286
 [<ffffffff838b3f36>] default_idle_call+0x36/0x60 kernel/sched/idle.c:97
 [<ffffffff81226790>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81226790>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81226790>] cpu_startup_entry+0x2b0/0x380 kernel/sched/idle.c:303
 [<ffffffff810b0243>] start_secondary+0x303/0x3e0 arch/x86/kernel/smpboot.c:254
Code: 
c8b 
c05 
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c72 
c04 
c85 
cc0 
c0f 
c84 
c81 
c00 
c00 
c00 
c45 
c31 
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c49 
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c24 
c30 
c48 
cb8 
c00 
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c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
cfa 
c48 
cc1 
cea 
c03 
c80 
c3c 
c02 
c00 
c<0f> 
c85 
c55 
c0d 
c00 
c00 
c49 
c85 
c5c 
c24 
c30 
c74 
c7b 
c41 
cbc 
c01 
c00 
c00 
c00 
c48 
c83 
c