INFO: task blkid:22011 blocked for more than 120 seconds.
      Not tainted 4.4.105-gdcfa5fe #7
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D ffff8800b30bf548 28168 22011   1842 0x00000004
 ffff8800b30bf548 000000000031602b 0000000000029430 0000000041b58ab3
 ffffffff83fadd80 ffffffff81229100 ffff8801db51f878 ffff8801db51f8a0
 ffff8801db51ef98 ffff8801d38b8000 ffff8801d038c680 ffff8800b30b8000
Call Trace:
 [<ffffffff8373be8a>] schedule+0x9a/0x1c0 kernel/sched/core.c:3351
 [<ffffffff8374716c>] schedule_timeout+0x3fc/0xb80 kernel/time/timer.c:1508
 [<ffffffff83739e0e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4932
 [<ffffffff8373d13b>] io_schedule include/linux/sched.h:446 [inline]
 [<ffffffff8373d13b>] bit_wait_io+0x1b/0xc0 kernel/sched/wait.c:595
 [<ffffffff8373cc7f>] __wait_on_bit_lock+0x8f/0x140 kernel/sched/wait.c:434
 [<ffffffff813fdc8f>] __lock_page+0x18f/0x1f0 mm/filemap.c:888
 [<ffffffff8141bfd0>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff8141bfd0>] write_cache_pages+0x620/0xd80 mm/page-writeback.c:2216
 [<ffffffff8141c802>] generic_writepages+0xd2/0x150 mm/page-writeback.c:2335
 [<ffffffff8142209c>] do_writepages+0xdc/0x1d0 mm/page-writeback.c:2349
 [<ffffffff81402c5f>] __filemap_fdatawrite_range+0x16f/0x200 mm/filemap.c:347
 [<ffffffff81402d61>] __filemap_fdatawrite mm/filemap.c:355 [inline]
 [<ffffffff81402d61>] filemap_fdatawrite mm/filemap.c:360 [inline]
 [<ffffffff81402d61>] filemap_write_and_wait+0x51/0xf0 mm/filemap.c:499
 [<ffffffff815a783b>] __sync_blockdev fs/block_dev.c:178 [inline]
 [<ffffffff815a783b>] sync_blockdev.part.21+0x4b/0x60 fs/block_dev.c:187
 [<ffffffff815a7d98>] sync_blockdev fs/block_dev.c:174 [inline]
 [<ffffffff815a7d98>] __blkdev_put+0x168/0x740 fs/block_dev.c:1522
 [<ffffffff815a9103>] blkdev_put+0x73/0x4c0 fs/block_dev.c:1600
 [<ffffffff815a95d8>] blkdev_close+0x88/0xd0 fs/block_dev.c:1607
 [<ffffffff814fc722>] __fput+0x202/0x6c0 fs/file_table.c:208
 [<ffffffff814fcc49>] ____fput+0x9/0x10 fs/file_table.c:244
 [<ffffffff8117f618>] task_work_run+0xd8/0x160 kernel/task_work.c:115
 [<ffffffff810035b9>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff810035b9>] exit_to_usermode_loop+0x109/0x120 arch/x86/entry/common.c:251
 [<ffffffff81006376>] prepare_exit_to_usermode arch/x86/entry/common.c:282 [inline]
 [<ffffffff81006376>] syscall_return_slowpath+0x186/0x1c0 arch/x86/entry/common.c:347
 [<ffffffff8374a79e>] int_ret_from_sys_call+0x25/0x9f
1 lock held by blkid/22011:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff815a7ce9>] __blkdev_put+0xb9/0x740 fs/block_dev.c:1516
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 484 Comm: khungtaskd Not tainted 4.4.105-gdcfa5fe #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb371780 task.stack: ffff8800bb1f0000
RIP: 0010:[<ffffffff810bf397>]  [<ffffffff810bf397>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bf397>]  [<ffffffff810bf397>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bf397>]  [<ffffffff810bf397>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bf397>]  [<ffffffff810bf397>] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bb1f7cb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bb1f7ce0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: ffffffff8426aba0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c42327f000 CR3: 00000001d4de7000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426aba0 ffffffff847e7480 ffffffff847e4a24 0000000000000001
 dffffc0000000000 ffff8800bb1f7d00 ffffffff810b4ecb fffffbfff08fc944
 00000000000194a0 ffff8800bb1f7d68 ffffffff81cd3418 ffff8800bb1f7d28
Call Trace:
 [<ffffffff810b4ecb>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81cd3418>] nmi_trigger_all_cpu_backtrace+0x428/0x590 lib/nmi_backtrace.c:85
 [<ffffffff810b4f64>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8134cf46>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8134cf46>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8134cf46>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8134cf46>] watchdog+0x636/0xa20 kernel/hung_task.c:238
 [<ffffffff81184115>] kthread+0x245/0x310 kernel/kthread.c:211
 [<ffffffff8374a9ef>] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:468
Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 3b 97 16 00 4c 89 e7 57 9d 0f 1f 
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.105-gdcfa5fe #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801da691780 task.stack: ffff8801da6a0000
RIP: 0010:[<ffffffff81273b90>]  [<ffffffff81273b90>] __rcu_read_unlock+0x0/0x1a0 kernel/rcu/update.c:242
RSP: 0018:ffff8801da6a7d90  EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 1ffffffff08fc661
RDX: 0000000000000000 RSI: ffffffff839fd420 RDI: ffffffff847e3308
RBP: ffff8801da6a7db8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 1ffff1003b4d4f7e R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c4234e5020 CR3: 00000001d4de7000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff811889b0 ffffffff81188930 ffff8801da6a8000 ffffffff847d5588
 0000000000000000 ffff8801da6a7dc8 ffffffff811250f5 ffff8801da6a7dd8
 ffffffff8102829e ffff8801da6a7ea8 ffffffff812135a4 ffffffff812288db
Call Trace:
 [<ffffffff811250f5>] idle_notifier_call_chain+0x15/0x20 kernel/cpu.c:865
 [<ffffffff8102829e>] __exit_idle arch/x86/kernel/process.c:248 [inline]
 [<ffffffff8102829e>] arch_cpu_idle_exit+0x1e/0x20 arch/x86/kernel/process.c:269
 [<ffffffff812135a4>] cpu_idle_loop kernel/sched/idle.c:255 [inline]
 [<ffffffff812135a4>] cpu_startup_entry+0x2b4/0x820 kernel/sched/idle.c:301
 [<ffffffff810a9394>] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:251
Code: c0 74 f3 48 c7 c7 00 76 2b 84 e8 ac f6 fa ff 5d c3 e8 c5 68 26 00 eb 84 e8 be 68 26 00 eb b4 66 90 66 2e 0f 1f 84 00 00 00 00 00 <48> b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 54 53 65 48 8b 1c