Buffer I/O error on dev loop0, logical block 64, async page read INFO: task syz-executor6:14662 blocked for more than 120 seconds. Not tainted 4.15.0-rc4-next-20171221+ #78 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D24000 14662 3374 0x00000004 Call Trace: context_switch kernel/sched/core.c:2800 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3376 schedule+0xf5/0x430 kernel/sched/core.c:3435 io_schedule+0x1c/0x70 kernel/sched/core.c:5043 wait_on_page_bit_common mm/filemap.c:1099 [inline] __lock_page+0x574/0x720 mm/filemap.c:1272 lock_page include/linux/pagemap.h:483 [inline] write_cache_pages+0xb32/0x14b0 mm/page-writeback.c:2206 generic_writepages+0xe9/0x150 mm/page-writeback.c:2325 blkdev_writepages+0x1d/0x30 fs/block_dev.c:1939 do_writepages+0xff/0x170 mm/page-writeback.c:2340 __filemap_fdatawrite_range+0x32f/0x460 mm/filemap.c:444 SYSC_sync_file_range fs/sync.c:347 [inline] SyS_sync_file_range+0x1ac/0x210 fs/sync.c:283 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452ac9 RSP: 002b:00007fa16cf35c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000115 RAX: ffffffffffffffda RBX: 000000000071bf58 RCX: 0000000000452ac9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000014 RBP: 00000000000000be R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000212 R12: 00000000006ef270 R13: 00000000ffffffff R14: 00007fa16cf366d4 R15: 000000000000000c Showing all locks held in the system: 3 locks held by kworker/u4:2/27: #0: ((wq_completion)"writeback"){+.+.}, at: [<000000009a068d42>] process_one_work+0xaaf/0x1af0 kernel/workqueue.c:2083 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<00000000d0768c81>] process_one_work+0xb01/0x1af0 kernel/workqueue.c:2087 #2: (&type->s_umount_key#25){.+.+}, at: [<00000000923049cb>] trylock_super+0x20/0x100 fs/super.c:395 2 locks held by khungtaskd/676: #0: (rcu_read_lock){....}, at: [<0000000096a41f07>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<0000000096a41f07>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000001ff92064>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 1 lock held by rsyslogd/3001: #0: (&f->f_pos_lock){+.+.}, at: [<000000002a2698bb>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/3123: #0: (&tty->ldisc_sem){++++}, at: [<00000000f7c565f5>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e46f20f3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3124: #0: (&tty->ldisc_sem){++++}, at: [<00000000f7c565f5>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e46f20f3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3125: #0: (&tty->ldisc_sem){++++}, at: [<00000000f7c565f5>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e46f20f3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3126: #0: (&tty->ldisc_sem){++++}, at: [<00000000f7c565f5>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e46f20f3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3127: #0: (&tty->ldisc_sem){++++}, at: [<00000000f7c565f5>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e46f20f3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3128: #0: (&tty->ldisc_sem){++++}, at: [<00000000f7c565f5>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e46f20f3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3129: #0: (&tty->ldisc_sem){++++}, at: [<00000000f7c565f5>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e46f20f3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 676 Comm: khungtaskd Not tainted 4.15.0-rc4-next-20171221+ #78 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc4-next-20171221+ #78 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RIP: 0010:__lock_acquire+0x210/0x3e00 kernel/locking/lockdep.c:3318 RSP: 0018:ffff8801db207750 EFLAGS: 00000006 RAX: ffffffff875b66a0 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 1ffffffff0f52ffa RSI: 0000000000000000 RDI: ffffffff87a97fd0 RBP: ffff8801db207ae0 R08: ffffffff8163f4ce R09: 0000000000000001 R10: 0000000000000000 R11: ffffffff87a97fc8 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000002 R15: ffffffff8642c340 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42003d840 CR3: 0000000006422003 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] ktime_get+0x12f/0x3a0 kernel/time/timekeeping.c:762 tick_nohz_irq_enter kernel/time/tick-sched.c:1102 [inline] tick_irq_enter+0x9e/0x390 kernel/time/tick-sched.c:1123 irq_enter+0xb6/0xd0 kernel/softirq.c:346 scheduler_ipi+0x23d/0x820 kernel/sched/core.c:1794 smp_reschedule_interrupt+0xe6/0x670 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:944 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff86407c38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff0c80f8a RCX: 0000000000000000 RDX: 1ffffffff0c990a8 RSI: 0000000000000001 RDI: ffffffff864c8540 RBP: ffffffff86407c38 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff86407cf0 R14: ffffffff86be46e0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline] default_idle+0xbf/0x430 arch/x86/kernel/process.c:354 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:345 default_idle_call+0x36/0x90 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:246 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:351 rest_init+0xed/0xf0 init/main.c:436 start_kernel+0x7f1/0x819 init/main.c:716 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 Code: fc ff ff 8b 8d e0 fc ff ff 44 8b 8d d8 fc ff ff 4c 8b 85 d0 fc ff ff 44 8b 95 c8 fc ff ff 0f 84 9b 07 00 00 f0 ff 80 38 01 00 00 <49> 8d bf 70 08 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 fe 48