Buffer I/O error on dev loop0, logical block 122, lost async page write Buffer I/O error on dev loop0, logical block 116, lost async page write Buffer I/O error on dev loop0, logical block 124, lost async page write buffer_io_error: 5 callbacks suppressed Buffer I/O error on dev loop0, logical block 0, async page read INFO: task syz-executor1:12878 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #5 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D16688 12878 7829 0x00000006 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 mm/filemap.c:1099 [inline] __lock_page+0x574/0x720 mm/filemap.c:1272 lock_page include/linux/pagemap.h:483 [inline] write_cache_pages+0xb33/0x14b0 mm/page-writeback.c:2206 generic_writepages+0xe9/0x150 mm/page-writeback.c:2325 blkdev_writepages+0x1d/0x30 fs/block_dev.c:1954 do_writepages+0xff/0x170 mm/page-writeback.c:2340 __filemap_fdatawrite_range+0x32f/0x460 mm/filemap.c:444 filemap_write_and_wait_range+0x59/0xc0 mm/filemap.c:655 __generic_file_write_iter+0x456/0x5b0 mm/filemap.c:3249 blkdev_write_iter+0x207/0x3e0 fs/block_dev.c:1908 call_write_iter include/linux/fs.h:1782 [inline] do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 vfs_iter_write+0x77/0xb0 fs/read_write.c:945 iter_file_splice_write+0x7db/0xf30 fs/splice.c:749 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x125/0x180 fs/splice.c:1018 splice_direct_to_actor+0x2c1/0x820 fs/splice.c:973 do_splice_direct+0x29b/0x3c0 fs/splice.c:1061 do_sendfile+0x5c9/0xe80 fs/read_write.c:1413 SYSC_sendfile64 fs/read_write.c:1468 [inline] SyS_sendfile64+0xbd/0x160 fs/read_write.c:1460 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4548b9 RSP: 002b:00007fbc3edcec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fbc3edcf6d4 RCX: 00000000004548b9 RDX: 0000000020000080 RSI: 0000000000000013 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000102000004 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004c5 R14: 00000000006f9318 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/868: #0: (rcu_read_lock){....}, at: [<0000000021c76590>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<0000000021c76590>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000f5bc59ac>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4403: #0: (&tty->ldisc_sem){++++}, at: [<00000000cdeaf373>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009656f194>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4404: #0: (&tty->ldisc_sem){++++}, at: [<00000000cdeaf373>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009656f194>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4405: #0: (&tty->ldisc_sem){++++}, at: [<00000000cdeaf373>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009656f194>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4406: #0: (&tty->ldisc_sem){++++}, at: [<00000000cdeaf373>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009656f194>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4407: #0: (&tty->ldisc_sem){++++}, at: [<00000000cdeaf373>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009656f194>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4408: #0: (&tty->ldisc_sem){++++}, at: [<00000000cdeaf373>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009656f194>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4409: #0: (&tty->ldisc_sem){++++}, at: [<00000000cdeaf373>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009656f194>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 3 locks held by kworker/u4:13/14522: #0: ((wq_completion)"writeback"){+.+.}, at: [<000000004bec0366>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000004bec0366>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000004bec0366>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000004bec0366>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<00000000852dedd1>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (&type->s_umount_key#33){++++}, at: [<000000001727767b>] trylock_super+0x20/0x100 fs/super.c:395 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 868 Comm: khungtaskd Not tainted 4.16.0-rc7+ #5 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.16.0-rc7+ #5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xa/0x50 kernel/kcov.c:100 RSP: 0018:ffff8801db207ac0 EFLAGS: 00000046 RAX: ffffffff87a2d200 RBX: 0000000000000001 RCX: ffffffff8161d042 RDX: 1ffff1003b644ccb RSI: 00000072dd88f396 RDI: ffff8801db226658 RBP: ffff8801db207b28 R08: 0000000000000000 R09: 1ffff1003b640f1e R10: dffffc0000000000 R11: 0000000000000000 R12: ffff8801db226620 R13: 00000072dd88c5c0 R14: 00000000000f4240 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc8805bae30 CR3: 0000000007a22002 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: tick_sched_timer+0xb6/0x120 kernel/time/tick-sched.c:1202 __run_hrtimer kernel/time/hrtimer.c:1349 [inline] __hrtimer_run_queues+0x39c/0xec0 kernel/time/hrtimer.c:1411 hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff87a07c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff12 RAX: dffffc0000000000 RBX: 1ffffffff0f40f8a RCX: 0000000000000000 RDX: 1ffffffff0f59580 RSI: 0000000000000001 RDI: ffffffff87acac00 RBP: ffffffff87a07c38 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff87a07cf0 R14: ffffffff883b4820 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 rest_init+0xed/0xf0 init/main.c:437 start_kernel+0x7f1/0x819 init/main.c:717 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:239 Code: 32 fd ff ff 48 8b bd d0 fe ff ff e8 61 47 38 00 e9 c3 fc ff ff 90 90 90 90 90 90 90 90 90 90 90 90 55 65 48 8b 04 25 c0 ed 01 00 <48> 89 e5 65 8b 15 1c 24 90 7e 81 e2 00 01 1f 00 48 8b 4d 08 75