kworker/u4:6(11548): getblk(): executed=9 bh_count=0 bh_state=0
kworker/u4:6(11548): getblk(): executed=9 bh_count=0 bh_state=0
kworker/u4:6(11548): getblk(): executed=9 bh_count=0 bh_state=0
kworker/u4:6(11548): getblk(): executed=9 bh_count=0 bh_state=0
kworker/u4:6(11548): getblk(): executed=9 bh_count=0 bh_state=0
INFO: task syz-executor4:22509 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc6-next-20181005+ #88
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D24472 22509  20373 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2830 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3479
 schedule+0xfe/0x460 kernel/sched/core.c:3523
 wb_wait_for_completion+0x1f9/0x2d0 fs/fs-writeback.c:221
 sync_inodes_sb+0x33e/0x480 fs/fs-writeback.c:2417
 sync_inodes_one_sb+0x59/0x70 fs/sync.c:74
 iterate_supers+0x149/0x290 fs/super.c:724
 ksys_sync+0xec/0x1e0 fs/sync.c:113
 __ia32_sys_sync+0xe/0x20 fs/sync.c:124
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: Bad RIP value.
RSP: 002b:00007f4581bccc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 000000000072bf08 RCX: 0000000000457579
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4581bcd6d4
R13: 00000000004c2ec2 R14: 00000000004d7ad0 R15: 00000000ffffffff
INFO: task syz-executor4:22511 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc6-next-20181005+ #88
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D23240 22511  20373 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2830 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3479
 schedule+0xfe/0x460 kernel/sched/core.c:3523
 wb_wait_for_completion+0x1f9/0x2d0 fs/fs-writeback.c:221
 sync_inodes_sb+0x33e/0x480 fs/fs-writeback.c:2417
 sync_inodes_one_sb+0x59/0x70 fs/sync.c:74
 iterate_supers+0x149/0x290 fs/super.c:724
 ksys_sync+0xec/0x1e0 fs/sync.c:113
 __ia32_sys_sync+0xe/0x20 fs/sync.c:124
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: Bad RIP value.
RSP: 002b:00007f4581babc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 000000000072bfa8 RCX: 0000000000457579
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4581bac6d4
R13: 00000000004c2ec2 R14: 00000000004d7ad0 R15: 00000000ffffffff
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 980 Comm: khungtaskd Not tainted 4.19.0-rc6-next-20181005+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1c2/0x22c 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:144 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
 watchdog+0xb39/0x1050 kernel/hung_task.c:265
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.395 msecs
NMI backtrace for cpu 0
CPU: 0 PID: 11548 Comm: kworker/u4:6 Not tainted 4.19.0-rc6-next-20181005+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:trace_hardirqs_off+0xfd/0x310 kernel/trace/trace_preemptirq.c:40
Code: 28 00 00 00 0f 85 e6 01 00 00 48 83 c4 78 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 9f ed f9 ff 48 8b 45 00 4c 8b 75 08 48 8b 40 08 <48> 89 85 70 ff ff ff 0f 1f 44 00 00 eb 9f e8 80 ed f9 ff 4c 8d 6d
RSP: 0018:ffff88017d7d6108 EFLAGS: 00000093
RAX: ffffffff81dff703 RBX: 1ffff1002fafac24 RCX: ffffffff81838fe5
RDX: 0000000000000000 RSI: ffffffff81839031 RDI: 0000000000000005
RBP: ffff88017d7d61a8 R08: ffff8801c4760400 R09: fffff94000d9fd1e
R10: fffff94000d9fd1e R11: ffffea0006cfe8f7 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff81dfe56d R15: 1ffff1002fafac8d
FS:  0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001d5b67000 CR4: 00000000001406f0
Call Trace:
 lookup_bh_lru fs/buffer.c:1290 [inline]
 __find_get_block+0x14d/0xf10 fs/buffer.c:1321
 __getblk_slow fs/buffer.c:1058 [inline]
 __getblk_gfp+0x3d3/0x1030 fs/buffer.c:1351
 __bread_gfp+0x2d/0x300 fs/buffer.c:1385
 sb_bread include/linux/buffer_head.h:307 [inline]
 __fat_write_inode+0x347/0xb60 fs/fat/inode.c:860
 fat_write_inode+0x97/0x180 fs/fat/inode.c:909
 write_inode fs/fs-writeback.c:1176 [inline]
 __writeback_single_inode+0xf4a/0x1650 fs/fs-writeback.c:1375
 writeback_sb_inodes+0x71f/0x1210 fs/fs-writeback.c:1580
 __writeback_inodes_wb+0x1b9/0x340 fs/fs-writeback.c:1649
 wb_writeback+0xa64/0xfb0 fs/fs-writeback.c:1758
 wb_check_start_all fs/fs-writeback.c:1882 [inline]
 wb_do_writeback fs/fs-writeback.c:1908 [inline]
 wb_workfn+0xedf/0x1780 fs/fs-writeback.c:1942
 process_one_work+0xc8b/0x1b80 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352