INFO: task syz-executor4:15960 blocked for more than 120 seconds.
      Not tainted 4.9.107-gdb2c520 #49
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D28928 15960   3896 0x00000004
 ffff8801d426b000 ffff8801d98ed500 ffff8801d98ef480 ffff88018b206000
 ffff8801db321c18 ffff8801d803f890 ffffffff839e8c1d 1ffff1003b007f06
 ffffffff855802f0 0000000041b58ab3 00ffffff843c2388 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f6631>] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768
 [<ffffffff839e83fa>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180
 [<ffffffff839eb669>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff839eb669>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff839eaf0e>] __wait_on_bit_lock+0xce/0x1c0 kernel/sched/wait.c:421
 [<ffffffff8143451f>] __lock_page+0xff/0x160 mm/filemap.c:934
 [<ffffffff8143a2e9>] lock_page include/linux/pagemap.h:454 [inline]
 [<ffffffff8143a2e9>] pagecache_get_page+0x409/0x720 mm/filemap.c:1216
 [<ffffffff8146bbe6>] find_lock_page include/linux/pagemap.h:284 [inline]
 [<ffffffff8146bbe6>] truncate_inode_pages_range+0xca6/0x1290 mm/truncate.c:320
 [<ffffffff816327fd>] blkdev_fallocate+0x21d/0x440 fs/block_dev.c:1817
 [<ffffffff81568629>] vfs_fallocate+0x359/0x600 fs/open.c:329
 [<ffffffff8156b533>] SYSC_fallocate fs/open.c:352 [inline]
 [<ffffffff8156b533>] SyS_fallocate+0x53/0x90 fs/open.c:346
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136662c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136662c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425cb7>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3775:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f7cc2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211fc62>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor4/15960:
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff815685cb>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff815685cb>] vfs_fallocate+0x2fb/0x600 fs/open.c:328
1 lock held by syz-executor4/16008:
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff815685cb>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff815685cb>] vfs_fallocate+0x2fb/0x600 fs/open.c:328

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.107-gdb2c520 #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8487d08 ffffffff81eb3da9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d8487d40
 ffffffff81ebf0a7 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb3da9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3da9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf0a7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf03a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b97a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366bc4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366bc4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366bc4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366bc4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9cdc>] 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
CPU: 1 PID: 3676 Comm: rs:main Q:Reg Not tainted 4.9.107-gdb2c520 #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801c5a76000 task.stack: ffff8801c4e80000
RIP: 0010:[<ffffffff812365fb>] 
c [<ffffffff812365fb>] mark_irqflags kernel/locking/lockdep.c:2908 [inline]
RIP: 0010:[<ffffffff812365fb>] 
c [<ffffffff812365fb>] __lock_acquire+0x49b/0x4070 kernel/locking/lockdep.c:3302
RSP: 0018:ffff8801c4e871e0  EFLAGS: 00000097
RAX: 0000000000000000 RBX: ffff8801c5a769b8 RCX: ffff8801c5a769d9
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8801c5a769dc
RBP: ffff8801c4e87388 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8801c5a76000 R11: 1ffff10038b4ed36 R12: 000000000000035c
R13: 0000000000000006 R14: ffff8801c5a768b4 R15: 0000000000000003
FS:  00007fc8e2a92700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000192eb10 CR3: 00000001c5881000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 000000000000035c
c 0000000000000005
c 0000000000000000
c ffff8801c5a769b2
c
 ffff8801c4e873c0
c ffff8801c5a769b8
c 0000000000000024
c 0000000000000006
c
 ffff8801c5a768b4
c 0000000000000000
c ffff8801c4e873e8
c ffffffff812367b4
c
Call Trace:
 [<ffffffff8123ac40>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff839f8eb6>] __raw_spin_lock include/linux/spinlock_api_smp.h:144 [inline]
 [<ffffffff839f8eb6>] _raw_spin_lock+0x36/0x50 kernel/locking/spinlock.c:151
 [<ffffffff8174cab1>] spin_lock include/linux/spinlock.h:302 [inline]
 [<ffffffff8174cab1>] ext4_do_update_inode fs/ext4/inode.c:4915 [inline]
 [<ffffffff8174cab1>] ext4_mark_iloc_dirty+0x1d1/0x2780 fs/ext4/inode.c:5482
 [<ffffffff8174f59f>] ext4_mark_inode_dirty+0x3bf/0xb40 fs/ext4/inode.c:5598
 [<ffffffff817ff4aa>] ext4_ext_truncate+0x9a/0x280 fs/ext4/extents.c:4642
 [<ffffffff817547b5>] ext4_truncate+0xa15/0x12c0 fs/ext4/inode.c:4259
 [<ffffffff8175694b>] ext4_truncate_failed_write fs/ext4/truncate.h:15 [inline]
 [<ffffffff8175694b>] ext4_da_write_begin+0x4eb/0x1020 fs/ext4/inode.c:3015
 [<ffffffff81435c91>] generic_perform_write+0x301/0x510 mm/filemap.c:2740
 [<ffffffff8143d722>] __generic_file_write_iter+0x352/0x540 mm/filemap.c:2865
 [<ffffffff8172cea3>] ext4_file_write_iter+0x463/0xd90 fs/ext4/file.c:165
 [<ffffffff8156ead0>] new_sync_write fs/read_write.c:496 [inline]
 [<ffffffff8156ead0>] __vfs_write+0x3e0/0x580 fs/read_write.c:509
 [<ffffffff815728c7>] vfs_write+0x187/0x530 fs/read_write.c:557
 [<ffffffff815766f9>] SYSC_write fs/read_write.c:604 [inline]
 [<ffffffff815766f9>] SyS_write+0xd9/0x1c0 fs/read_write.c:596
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c43 
c24 
c0f 
c84 
cc7 
c01 
c00 
c00 
c48 
c8d 
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c21 
c48 
cb8 
c00 
c00 
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c00 
c00 
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cff 
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c48 
c89 
cca 
c48 
cc1 
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c03 
c0f 
cb6 
c04 
c02 
c48 
c89 
cca 
c83 
ce2 
c07 
c38 
cd0 
c7f 
c08 
c<84> 
cc0 
c0f 
c85 
c21 
c11 
c00 
c00 
c4c 
c8d 
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c22 
c0f 
cb6 
c53 
c21 
c48 
cb8 
c00 
c00 
c00 
c