Buffer I/O error on dev loop0, logical block 6, lost async page write Buffer I/O error on dev loop0, logical block 7, lost async page write Buffer I/O error on dev loop0, logical block 8, lost async page write Buffer I/O error on dev loop0, logical block 9, lost async page write Buffer I/O error on dev loop0, logical block 10, lost async page write INFO: task syz-executor0:16227 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #278 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D22576 16227 4437 0x20020004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 io_schedule+0x1c/0x70 kernel/sched/core.c:5115 wait_on_page_bit_common+0x4b3/0x770 mm/filemap.c:1099 wait_on_page_bit mm/filemap.c:1132 [inline] wait_on_page_writeback include/linux/pagemap.h:546 [inline] __filemap_fdatawait_range+0x282/0x430 mm/filemap.c:533 filemap_fdatawait_range mm/filemap.c:558 [inline] filemap_fdatawait include/linux/fs.h:2591 [inline] filemap_write_and_wait+0x7a/0xd0 mm/filemap.c:624 __sync_blockdev fs/block_dev.c:448 [inline] sync_blockdev.part.30+0x50/0x70 fs/block_dev.c:457 sync_blockdev fs/block_dev.c:444 [inline] __blkdev_put+0x18b/0x760 fs/block_dev.c:1781 blkdev_put+0x85/0x4f0 fs/block_dev.c:1850 blkdev_close+0x8b/0xb0 fs/block_dev.c:1857 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_32_irqs_on arch/x86/entry/common.c:336 [inline] do_fast_syscall_32+0xbe6/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f50c99 RSP: 002b:00000000f774c09c EFLAGS: 00000286 ORIG_RAX: 0000000000000036 RAX: 0000000000000000 RBX: 0000000000000014 RCX: 0000000000004c01 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/869: #0: (rcu_read_lock){....}, at: [<000000004b29a644>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000004b29a644>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000004eafdc16>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4368: #0: (&tty->ldisc_sem){++++}, at: [<00000000da4af207>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b987d67c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4369: #0: (&tty->ldisc_sem){++++}, at: [<00000000da4af207>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b987d67c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4370: #0: (&tty->ldisc_sem){++++}, at: [<00000000da4af207>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b987d67c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4371: #0: (&tty->ldisc_sem){++++}, at: [<00000000da4af207>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b987d67c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4372: #0: (&tty->ldisc_sem){++++}, at: [<00000000da4af207>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b987d67c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4373: #0: (&tty->ldisc_sem){++++}, at: [<00000000da4af207>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b987d67c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4374: #0: (&tty->ldisc_sem){++++}, at: [<00000000da4af207>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000b987d67c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 3 locks held by kworker/u4:10/6324: #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000e3ad4cac>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000e3ad4cac>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000e3ad4cac>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000e3ad4cac>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<00000000c2f3e7df>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (&type->s_umount_key#33){++++}, at: [<000000000a5c1c2b>] trylock_super+0x20/0x100 fs/super.c:395 1 lock held by syz-executor0/16227: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000a9d3761b>] __blkdev_put+0xbc/0x760 fs/block_dev.c:1775 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 869 Comm: khungtaskd Not tainted 4.16.0-rc7+ #278 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+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 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+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.16.0-rc7+ #278 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:find_busiest_group+0x0/0x1c60 kernel/sched/fair.c:8028 RSP: 0018:ffff8801db307418 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff8801d9a62580 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff8801db31f618 RDI: ffff8801db307750 RBP: ffff8801db307818 R08: ffff8801db3078c0 R09: dffffc0000000000 R10: ffff8801d9a6c7d8 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8801db3077f0 R14: ffff8801db307750 R15: ffffed003b660ef1 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000007a22006 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rebalance_domains+0x786/0xcc0 kernel/sched/fair.c:9183 run_rebalance_domains+0x378/0x770 kernel/sched/fair.c:9405 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 scheduler_ipi+0x318/0x820 kernel/sched/core.c:1804 smp_reschedule_interrupt+0xe6/0x650 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:881 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffff8801d9b1fcb0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b363f99 RCX: 0000000000000000 RDX: 1ffffffff0f59580 RSI: 0000000000000001 RDI: ffffffff87acac00 RBP: ffff8801d9b1fcb0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801d9b1fd68 R14: ffffffff883b4a20 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [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 start_secondary+0x40a/0x590 arch/x86/kernel/smpboot.c:267 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 Code: e9 71 dd ff ff e8 01 e0 57 00 e9 30 de ff ff e8 17 e0 57 00 e9 6a f0 ff ff e8 8d e0 57 00 e9 e4 ed ff ff 0f 1f 84 00 00 00 00 00 <55> 48 ba 00 00 00 00 00 fc ff df 49 89 f8 48 89 e5 41 57 41 56