Buffer I/O error on dev loop0, logical block 6, lost async page write
Buffer I/O error on dev loop0, logical block 7, lost async page write
Buffer I/O error on dev loop0, logical block 8, lost async page write
Buffer I/O error on dev loop0, logical block 9, lost async page write
bond0 (unregistering): Released all slaves
INFO: task syz-executor3:1730 blocked for more than 120 seconds.
      Not tainted 4.16.0-rc3+ #330
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D19536  1730   4247 0x80000006
Call Trace:
 context_switch kernel/sched/core.c:2862 [inline]
 __schedule+0x905/0x2070 kernel/sched/core.c:3440
 schedule+0xf5/0x430 kernel/sched/core.c:3499
 io_schedule+0x1c/0x70 kernel/sched/core.c:5115
 wait_on_page_bit_common+0x4b3/0x770 mm/filemap.c:1099
 wait_on_page_bit mm/filemap.c:1132 [inline]
 wait_on_page_writeback include/linux/pagemap.h:546 [inline]
 __filemap_fdatawait_range+0x282/0x430 mm/filemap.c:533
 filemap_fdatawait_range mm/filemap.c:558 [inline]
 filemap_fdatawait include/linux/fs.h:2590 [inline]
 filemap_write_and_wait+0x7a/0xd0 mm/filemap.c:624
 __sync_blockdev fs/block_dev.c:448 [inline]
 sync_blockdev.part.29+0x50/0x70 fs/block_dev.c:457
 sync_blockdev fs/block_dev.c:444 [inline]
 __blkdev_put+0x18b/0x7f0 fs/block_dev.c:1763
 blkdev_put+0x85/0x4f0 fs/block_dev.c:1835
 blkdev_close+0x8b/0xb0 fs/block_dev.c:1842
 __fput+0x327/0x7e0 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x199/0x270 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9bb/0x1ad0 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 get_signal+0x73a/0x16d0 kernel/signal.c:2469
 do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
 do_syscall_64+0x6e5/0x940 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453d69
RSP: 002b:00007f890470fc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: 000000000000f000 RBX: 00007f89047106d4 RCX: 0000000000453d69
RDX: 00000000200ddff8 RSI: 0000000000000017 RDI: 0000000000000013
RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000102000001 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004a2 R14: 00000000006f6fd0 R15: 0000000000000001

Showing all locks held in the system:
3 locks held by kworker/u4:1/21:
 #0:  ((wq_completion)"writeback"){+.+.}, at: [<0000000077ccd9a8>] process_one_work+0xaaf/0x1af0 kernel/workqueue.c:2084
 #1:  ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<00000000ee834e6a>] process_one_work+0xb01/0x1af0 kernel/workqueue.c:2088
 #2:  (&type->s_umount_key#27){.+.+}, at: [<0000000000cdb93e>] trylock_super+0x20/0x100 fs/super.c:395
2 locks held by khungtaskd/798:
 #0:  (rcu_read_lock){....}, at: [<000000001ded005c>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0:  (rcu_read_lock){....}, at: [<000000001ded005c>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
 #1:  (tasklist_lock){.+.+}, at: [<000000006fef8d7f>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4046:
 #0:  (&f->f_pos_lock){+.+.}, at: [<000000005e5b3e0f>] __fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4167:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005027e814>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000007e28250f>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4168:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005027e814>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000007e28250f>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4169:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005027e814>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000007e28250f>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4170:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005027e814>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000007e28250f>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4171:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005027e814>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000007e28250f>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4172:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005027e814>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000007e28250f>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
2 locks held by getty/4173:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005027e814>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<000000007e28250f>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131
1 lock held by syz-executor3/1730:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<0000000035b53f24>] __blkdev_put+0xbc/0x7f0 fs/block_dev.c:1757
1 lock held by blkid/1748:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<00000000ed9d79be>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439

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

NMI backtrace for cpu 1
CPU: 1 PID: 798 Comm: khungtaskd Not tainted 4.16.0-rc3+ #330
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0x90c/0xd60 kernel/hung_task.c:249
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:407
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54