sd 0:0:1:0: [sda] tag#708 abort
sd 0:0:1:0: [sda] tag#707 abort
sd 0:0:1:0: [sda] tag#706 abort
sd 0:0:1:0: [sda] tag#705 abort
sd 0:0:1:0: [sda] tag#704 abort
INFO: task kworker/u4:0:6 blocked for more than 120 seconds.
      Not tainted 4.9.100-g73fdfa3 #29
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:0    D26536     6      2 0x00000000
Workqueue: writeback wb_workfn (flush-8:0)
 ffff8801d9a38000 0000000000000000 ffff8801c1c8ca80 ffff8801d5ca1800
 ffff8801db321b98 ffff8801d9a47390 ffffffff839e373d 0000000000000002
 ffff8801d9a47328 ffff8801d9a47328 00ffffff8121f1e0 ffff8801db322468
Call Trace:
 [<ffffffff839e4d3f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff8189fb97>] jbd2_log_wait_commit+0x297/0x3e0 fs/jbd2/journal.c:721
 [<ffffffff818a6198>] __jbd2_journal_force_commit+0x108/0x210 fs/jbd2/journal.c:572
 [<ffffffff818a62b5>] jbd2_journal_force_commit_nested+0x15/0x20 fs/jbd2/journal.c:591
 [<ffffffff8174e6b0>] ext4_writepages+0x17b0/0x2e50 fs/ext4/inode.c:2844
 [<ffffffff8145ca7f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2347
 [<ffffffff815ff0c9>] __writeback_single_inode+0xd9/0x1020 fs/fs-writeback.c:1320
 [<ffffffff81600b5c>] writeback_sb_inodes+0x4ac/0xe70 fs/fs-writeback.c:1584
 [<ffffffff8160161b>] __writeback_inodes_wb+0xfb/0x1e0 fs/fs-writeback.c:1653
 [<ffffffff81601da2>] wb_writeback+0x512/0xbd0 fs/fs-writeback.c:1762
 [<ffffffff8160b6d0>] wb_check_old_data_flush fs/fs-writeback.c:1877 [inline]
 [<ffffffff8160b6d0>] wb_do_writeback fs/fs-writeback.c:1901 [inline]
 [<ffffffff8160b6d0>] wb_workfn+0x850/0xdb0 fs/fs-writeback.c:1930
 [<ffffffff8118ae31>] process_one_work+0x7e1/0x1500 kernel/workqueue.c:2092
 [<ffffffff8118bc26>] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226
 [<ffffffff8119ad5d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f47dc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
4 locks held by kworker/u4:0/6:
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118ad3e>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118ad3e>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118ad3e>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118ad3e>] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff8118ad78>] process_one_work+0x728/0x1500 kernel/workqueue.c:2089
 #2:  (&type->s_umount_key#23){++++.+}, at: [<ffffffff81579ef0>] trylock_super+0x20/0xf0 fs/super.c:393
 #3:  (&sbi->s_journal_flag_rwsem){.+.+.+}, at: [<ffffffff8145ca7f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2347
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646ec>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646ec>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423c00>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3686:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d56bc>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3783:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f27e2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211cc32>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
3 locks held by syz-executor4/8116:
 #0:  (&sbi->s_journal_flag_rwsem){.+.+.+}, at: [<ffffffff8145ca7f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2347
 #1:  (jbd2_handle){++++..}, at: [<ffffffff81880bd3>] start_this_handle+0x443/0xe40 fs/jbd2/transaction.c:387
 #2:  (&ei->i_data_sem){++++..}, at: [<ffffffff8173f993>] ext4_map_blocks+0x6d3/0x16d0 fs/ext4/inode.c:605
2 locks held by syz-executor3/8124:
 #0:  (sb_writers#3){.+.+.+}, at: [<ffffffff81565efb>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#3){.+.+.+}, at: [<ffffffff81565efb>] vfs_fallocate+0x2fb/0x600 fs/open.c:328
 #1:  (&sb->s_type->i_mutex_key#9){++++++}, at: [<ffffffff81800237>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#9){++++++}, at: [<ffffffff81800237>] ext4_fallocate+0x5c7/0x1d70 fs/ext4/extents.c:4968

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.100-g73fdfa3 #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d846fd08 ffffffff81eb0f09 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b7da0 ffff8801d846fd40
 ffffffff81ebc207 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb0f09>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0f09>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebc207>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebc19a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b7ea4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81364c84>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364c84>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364c84>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364c84>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad5d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f47dc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff839f3246