Buffer I/O error on dev loop5, logical block 3, lost async page write
INFO: task syz-executor2:16668 blocked for more than 120 seconds.
      Not tainted 4.9.51-g60cc09a #52
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D26896 16668  16650 0x00000006
 ffff8801d5b36000 0000000000000000 ffff8801c515df80 ffff8801da29b000
 ffff8801db321518 ffff8801c4d672f0 ffffffff8389addb ffffffff8123b950
 ffffffff816229fb 00ff8801c4d67290 ffff8801db321e40 ffff8801db321e68
Call Trace:
 [<ffffffff8389c392>] schedule+0x92/0x1b0 kernel/sched/core.c:3625
 [<ffffffff838a85d3>] schedule_timeout+0x643/0x1220 kernel/time/timer.c:1770
 [<ffffffff8389a58e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5243
 [<ffffffff8389d809>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff8389d809>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff8389cee7>] __wait_on_bit+0x57/0x120 kernel/sched/wait.c:383
 [<ffffffff81431724>] wait_on_page_bit+0xf4/0x140 mm/filemap.c:802
 [<ffffffff81431931>] wait_on_page_writeback include/linux/pagemap.h:526 [inline]
 [<ffffffff81431931>] __filemap_fdatawait_range+0x1c1/0x2b0 mm/filemap.c:453
 [<ffffffff81431a45>] filemap_fdatawait_range+0x25/0x50 mm/filemap.c:483
 [<ffffffff8143a685>] filemap_fdatawait mm/filemap.c:533 [inline]
 [<ffffffff8143a685>] filemap_write_and_wait+0xf5/0x120 mm/filemap.c:551
 [<ffffffff8162bba0>] __sync_blockdev fs/block_dev.c:194 [inline]
 [<ffffffff8162bba0>] sync_blockdev.part.28+0x50/0x70 fs/block_dev.c:203
 [<ffffffff8162c1c4>] sync_blockdev fs/block_dev.c:190 [inline]
 [<ffffffff8162c1c4>] __blkdev_put+0x184/0x7e0 fs/block_dev.c:1583
 [<ffffffff8162d5f5>] blkdev_put+0x85/0x550 fs/block_dev.c:1661
 [<ffffffff8162db4b>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1668
 [<ffffffff81573f8c>] __fput+0x28c/0x6e0 fs/file_table.c:208
 [<ffffffff81574465>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff81195d75>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff8113d02e>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff8113d02e>] do_exit+0x82e/0x2a50 kernel/exit.c:833
 [<ffffffff81143718>] do_group_exit+0x108/0x320 kernel/exit.c:937
 [<ffffffff811663bc>] get_signal+0x55c/0x1600 kernel/signal.c:2315
 [<ffffffff81052c87>] do_signal+0x87/0x1960 arch/x86/kernel/signal.c:807
 [<ffffffff81003a35>] exit_to_usermode_loop+0xe5/0x130 arch/x86/entry/common.c:156
 [<ffffffff81006350>] prepare_exit_to_usermode arch/x86/entry/common.c:190 [inline]
 [<ffffffff81006350>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259
 [<ffffffff838ac5e6>] entry_SYSCALL_64_fastpath+0xc4/0xc6
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.51-g60cc09a #52
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d9a9fd00 ffffffff81d92f89 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810bd110 ffff8801d9a9fd38
 ffffffff81d9e09d 0000000000000001 0000000000000000 ffff8801d5b34c18
Call Trace:
 [<ffffffff81d92f89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d92f89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9e09d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9e1d7>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bd204>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813727e0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813727e0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813727e0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813727e0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119acdd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838ac7ea>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff838ab1b6