list_del corruption. next->prev should be 0000000003ec60cd, but was           (null)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:56!
invalid opcode: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3487 Comm: kworker/u4:5 Not tainted 4.15.0-rc3-next-20171213+ #66
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:__list_del_entry_valid+0x86/0x90 lib/list_debug.c:54
RSP: 0018:ffffc90002d93a80 EFLAGS: 00010082
RAX: 0000000000000054 RBX: ffff8801de2af000 RCX: ffffffff8123df0e
RDX: 0000000000000000 RSI: ffff88021fd136f8 RDI: ffff88021fd136f8
RBP: ffffc90002d93a80 R08: 0000000000000001 R09: 000000000000000c
R10: ffffc90002d93a50 R11: 000000000000000c R12: ffff8802151f4c50
R13: ffff8802153ab2d0 R14: ffff8802153ab2d0 R15: ffff880215339000
FS:  0000000000000000(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002009cd8 CR3: 00000001e2309000 CR4: 00000000001426e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000002
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 __list_del_entry include/linux/list.h:117 [inline]
 list_del_init include/linux/list.h:159 [inline]
 cfq_remove_request+0x33/0x200 block/cfq-iosched.c:2501
 cfq_dispatch_insert+0x5a/0x150 block/cfq-iosched.c:2993
 cfq_dispatch_request block/cfq-iosched.c:3510 [inline]
 cfq_dispatch_requests+0x4a9/0x1130 block/cfq-iosched.c:3544
 elv_next_request block/blk-core.c:2697 [inline]
 blk_peek_request+0x298/0x500 block/blk-core.c:2723
 scsi_request_fn+0x3b/0x7a0 drivers/scsi/scsi_lib.c:1796
 __blk_run_queue_uncond block/blk-core.c:409 [inline]
 __blk_run_queue+0x83/0x120 block/blk-core.c:429
 queue_unplugged+0x76/0x230 block/blk-core.c:3488
 blk_flush_plug_list+0x2fb/0x3a0 block/blk-core.c:3600
 blk_finish_plug+0x41/0x60 block/blk-core.c:3609
 wb_writeback+0x22e/0x690 fs/fs-writeback.c:1798
 wb_do_writeback fs/fs-writeback.c:1907 [inline]
 wb_workfn+0xaf/0x820 fs/fs-writeback.c:1948
 process_one_work+0x288/0x7a0 kernel/workqueue.c:2112
 worker_thread+0x43/0x4d0 kernel/workqueue.c:2246
 kthread+0x149/0x170 kernel/kthread.c:238
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524
Code: 78 30 e8 82 e8 74 e2 ae ff 0f 0b 48 89 f2 48 89 fe 48 c7 c7 b0 30 e8 82 e8 60 e2 ae ff 0f 0b 48 c7 c7 f0 30 e8 82 e8 52 e2 ae ff <0f> 0b 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41 56 41 55 41 
RIP: __list_del_entry_valid+0x86/0x90 lib/list_debug.c:54 RSP: ffffc90002d93a80
---[ end trace 22155b79e38fb2fb ]---
Kernel panic - not syncing: Fatal exception
Shutting down cpus with NMI
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..