INFO: task kworker/u4:0:6 blocked for more than 140 seconds.
      Not tainted 4.9.128+ #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:0    D24632     6      2 0x80000000
Workqueue: writeback wb_workfn (flush-8:0)
 ffff8801da678000 0000000000000000 ffff8801d4c60580 ffff8801da6b2f80
 ffff8801db721018 ffff8801da687130 ffffffff827e7bc2 ffff8801da678000
 0000000000000000 0000000000000000 0000000000000000 ffff8801db7218f0
Call Trace:
 [<ffffffff827e90ef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff817e4b65>] wait_transaction_locked+0x1a5/0x230 fs/jbd2/transaction.c:163
 [<ffffffff817e5038>] add_transaction_credits+0x408/0x980 fs/jbd2/transaction.c:191
 [<ffffffff817e59f0>] start_this_handle+0x340/0xe40 fs/jbd2/transaction.c:361
 [<ffffffff817e78a6>] jbd2__journal_start+0x306/0x8b0 fs/jbd2/transaction.c:457
 [<ffffffff8178d38c>] __ext4_journal_start_sb+0x10c/0x460 fs/ext4/ext4_jbd2.c:76
 [<ffffffff816d5335>] __ext4_journal_start fs/ext4/ext4_jbd2.h:318 [inline]
 [<ffffffff816d5335>] ext4_writepages+0xe75/0x2e00 fs/ext4/inode.c:2767
 [<ffffffff8143384f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2331
 [<ffffffff8159e6b9>] __writeback_single_inode+0xd9/0x1020 fs/fs-writeback.c:1320
 [<ffffffff8159faac>] writeback_sb_inodes+0x4ac/0xe70 fs/fs-writeback.c:1584
 [<ffffffff815a056b>] __writeback_inodes_wb+0xfb/0x1e0 fs/fs-writeback.c:1653
 [<ffffffff815a0b62>] wb_writeback+0x512/0xbd0 fs/fs-writeback.c:1762
 [<ffffffff815a42dc>] wb_check_old_data_flush fs/fs-writeback.c:1877 [inline]
 [<ffffffff815a42dc>] wb_do_writeback fs/fs-writeback.c:1901 [inline]
 [<ffffffff815a42dc>] wb_workfn+0x8bc/0xe90 fs/fs-writeback.c:1930
 [<ffffffff81130bb1>] process_one_work+0x831/0x1530 kernel/workqueue.c:2092
 [<ffffffff81131986>] worker_thread+0xd6/0x1140 kernel/workqueue.c:2226
 [<ffffffff8114272d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff827f801c>] 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: [<ffffffff81130abc>] process_one_work+0x73c/0x1530 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff81130af4>] process_one_work+0x774/0x1530 kernel/workqueue.c:2089
 #2:  (&type->s_umount_key#32){++++.+}, at: [<ffffffff81514650>] trylock_super+0x20/0xf0 fs/super.c:393
 #3:  (&sbi->s_journal_flag_rwsem){.+.+.+}, at: [<ffffffff8143384f>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2331
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131b80c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131b80c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fded4>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
3 locks held by rs:main Q:Reg/1887:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156c8dc>] __fdget_pos+0xac/0xd0 fs/file.c:781
 #1:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150aa5b>] file_start_write include/linux/fs.h:2640 [inline]
 #1:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150aa5b>] vfs_write+0x3eb/0x520 fs/read_write.c:556
 #2:  (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<ffffffff816b2832>] inode_lock include/linux/fs.h:766 [inline]
 #2:  (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<ffffffff816b2832>] ext4_file_write_iter+0x122/0xd70 fs/ext4/file.c:100
2 locks held by getty/2017:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff827f5f12>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81d1fc82>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
2 locks held by init/2148:
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150aa5b>] file_start_write include/linux/fs.h:2640 [inline]
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff8150aa5b>] vfs_write+0x3eb/0x520 fs/read_write.c:556
 #1:  (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<ffffffff816b2832>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<ffffffff816b2832>] ext4_file_write_iter+0x122/0xd70 fs/ext4/file.c:100

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.128+ #42
 ffff8801d9907d08 ffffffff81b2b9e9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff81098180 ffff8801d9907d40
 ffffffff81b36af9 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81b2b9e9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b2b9e9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b36af9>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b36a8c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff81098284>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131bd9d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131bd9d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131bd9d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131bd9d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff8114272d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff827f801c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2146 Comm: syz-executor541 Not tainted 4.9.128+ #42
task: ffff8801cc0a97c0 task.stack: ffff8801cb308000
RIP: 0010:[<ffffffff817732b3>] 
c [<ffffffff817732b3>] ext4_find_extent+0x43/0x940 fs/ext4/extents.c:875
RSP: 0018:ffff8801cb30f640  EFLAGS: 00000a03
RAX: dffffc0000000000 RBX: ffff8801cbf1eac0 RCX: 0000000040000000
RDX: 1ffff100397e3d1a RSI: ffffffff8177329e RDI: ffff8801cbf1e8d6
RBP: ffff8801cb30f6a0 R08: 000000000000000c R09: ffff8801cb30f390
R10: ffffed0039661e65 R11: ffff8801cb30f32f R12: 00000000c37f30da
R13: ffff8801cb30f8f8 R14: ffff8801cbf1e8d0 R15: 0000000000008002
FS:  00000000008fe880(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 00000001cb069000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffed0039661e65
c ffff8801cb30f6f8
c ffff8801cbf1eac0
c c37f30da40000000
c
 ffff8801cf481400
c ffff8801cb30f6a0
c ffffffff81772b9e
c ffff8801cf481400
c
 00000000c37f30da
c ffff8801cb30f8f8
c ffff8801cbf1eac0
c 0000000000008002
c
Call Trace:
 [<ffffffff817b9526>] get_ext_path fs/ext4/move_extent.c:39 [inline]
 [<ffffffff817b9526>] mext_check_coverage.constprop.2+0x256/0x400 fs/ext4/move_extent.c:106
 [<ffffffff817baf3b>] move_extent_per_page fs/ext4/move_extent.c:333 [inline]
 [<ffffffff817baf3b>] ext4_move_extents+0x17bb/0x2a50 fs/ext4/move_extent.c:681
 [<ffffffff816ed29c>] ext4_ioctl+0x27fc/0x3620 fs/ext4/ioctl.c:594
 [<ffffffff81546a4c>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff81546a4c>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff81546a4c>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff81547acf>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff81547acf>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff827f7e53>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c83 
cec 
c38 
c48 
c89 
c7d 
cb0 
c48 
c89 
c55 
ca8 
c89 
c75 
cbc 
c89 
c4d 
cb8 
ce8 
c02 
c7f 
cba 
cff 
c49 
c8d 
c7e 
c06 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
cfa 
c48 
cc1 
cea 
c03 
c<0f> 
cb6 
c14 
c02 
c48 
c89 
cf8 
c83 
ce0 
c07 
c83 
cc0 
c01 
c38 
cd0 
c7c 
c08 
c84 
cd2 
c0f 
c85 
c