INFO: task syz-executor2:891 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc3-next-20180706+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D21248   891  27095 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 io_schedule+0x1c/0x70 kernel/sched/core.c:5168
 bit_wait_io+0x18/0x90 kernel/sched/wait_bit.c:207
 __wait_on_bit+0xb3/0x130 kernel/sched/wait_bit.c:48
 out_of_line_wait_on_bit+0x213/0x3c0 kernel/sched/wait_bit.c:63
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 __wait_on_buffer fs/buffer.c:119 [inline]
 wait_on_buffer include/linux/buffer_head.h:354 [inline]
 __bread_slow fs/buffer.c:1177 [inline]
 __bread_gfp+0x2bd/0x310 fs/buffer.c:1358
 sb_bread include/linux/buffer_head.h:307 [inline]
 read_super_block+0x88/0x930 fs/reiserfs/super.c:1619
 reiserfs_fill_super+0xe08/0x3930 fs/reiserfs/super.c:1982
 mount_bdev+0x314/0x3e0 fs/super.c:1352
 get_super_block+0x3c/0x50 fs/reiserfs/super.c:2608
 legacy_get_tree+0x118/0x440 fs/fs_context.c:659
 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751
 do_new_mount fs/namespace.c:2567 [inline]
 do_mount+0x6c1/0x1fb0 fs/namespace.c:2889
 ksys_mount+0x12d/0x140 fs/namespace.c:3105
 __do_sys_mount fs/namespace.c:3119 [inline]
 __se_sys_mount fs/namespace.c:3116 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4585da
Code: 05 5b cb d4 01 48 89 04 24 e8 52 70 fb ff 48 8b ac 24 80 00 00 00 48 81 c4 88 00 00 00 c3 e8 dd 18 fd ff 0f 0b e8 d6 18 00 00 <e9> 91 fd ff ff cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 37 
RSP: 002b:00007f5ee91dca88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5ee91dcb30 RCX: 00000000004585da
RDX: 00007f5ee91dcad0 RSI: 0000000020000100 RDI: 00007f5ee91dcaf0
RBP: 0000000020000100 R08: 00007f5ee91dcb30 R09: 00007f5ee91dcad0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000015
R13: 0000000000000000 R14: 00000000004d39c0 R15: 0000000000000005
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 897 Comm: khungtaskd Not tainted 4.18.0-rc3-next-20180706+ #1
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+0x1c9/0x2b4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.5+0x19/0xce lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x151/0x192 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:143 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
 watchdog+0xb39/0x10b0 kernel/hung_task.c:265
 kthread+0x345/0x410 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 931 Comm: loop2 Not tainted 4.18.0-rc3-next-20180706+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:146
Code: 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 <55> 65 48 8b 04 25 40 ee 01 00 65 8b 15 5f 73 85 7e 48 89 e5 81 e2 
RSP: 0018:ffff88019f93e810 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff10033f27d05 RCX: ffffffff81a6251e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffff88019f93e970 R08: ffff88019f9c6500 R09: ffffed0033f27cc5
R10: ffffed0033f27cc5 R11: 0000000000000003 R12: ffffea0007186240
R13: ffff88019f93e948 R14: ffffea0007186240 R15: ffffea0006ec5388
FS:  0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001ca80e000 CR4: 00000000001406f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 find_lock_entry+0x1f4/0x8c0 mm/filemap.c:1461
 shmem_getpage_gfp+0x3cd/0x3ec0 mm/shmem.c:1610
 shmem_getpage mm/shmem.c:132 [inline]
 shmem_file_read_iter+0x399/0x1090 mm/shmem.c:2433
 call_read_iter include/linux/fs.h:1816 [inline]
 do_iter_readv_writev+0x790/0xa90 fs/read_write.c:678
 do_iter_read+0x26e/0x650 fs/read_write.c:922
 vfs_iter_read+0x77/0xb0 fs/read_write.c:936
 lo_read_simple drivers/block/loop.c:350 [inline]
 do_req_filebacked drivers/block/loop.c:615 [inline]
 loop_handle_cmd drivers/block/loop.c:1786 [inline]
 loop_queue_work+0x9ce/0x3afc drivers/block/loop.c:1800
 kthread_worker_fn+0x35f/0xa50 kernel/kthread.c:656
 loop_kthread_worker_fn+0x51/0x60 drivers/block/loop.c:892
 kthread+0x345/0x410 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.333 msecs