INFO: task blkid:21659 blocked for more than 120 seconds. Not tainted 4.15.0-rc8+ #180 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D20976 21659 3635 0x80000006 Call Trace: context_switch kernel/sched/core.c:2799 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 schedule+0xf5/0x430 kernel/sched/core.c:3434 io_schedule+0x1c/0x70 kernel/sched/core.c:5042 wait_on_page_bit_common mm/filemap.c:1100 [inline] __lock_page+0x574/0x720 mm/filemap.c:1273 lock_page include/linux/pagemap.h:483 [inline] truncate_inode_pages_range+0x1945/0x1f90 mm/truncate.c:452 truncate_inode_pages+0x24/0x30 mm/truncate.c:482 kill_bdev+0xbc/0xf0 fs/block_dev.c:86 __blkdev_put+0x198/0x7f0 fs/block_dev.c:1764 blkdev_put+0x85/0x4f0 fs/block_dev.c:1835 blkdev_close+0x8b/0xb0 fs/block_dev.c:1842 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73f/0x16c0 kernel/signal.c:2335 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 RIP: 0033:0x7fc6e78f2310 RSP: 002b:00007ffe776e8018 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffffc RBX: 0000000000000000 RCX: 00007fc6e78f2310 RDX: 0000000000000400 RSI: 0000000000e4fc58 RDI: 0000000000000003 RBP: 0000000000e4fc30 R08: 0000000000000028 R09: 0000000001680000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000e4f030 R13: 0000000000000400 R14: 0000000000e4f080 R15: 0000000000e4fc48 Showing all locks held in the system: 2 locks held by khungtaskd/746: #0: (rcu_read_lock){....}, at: [<00000000641daed1>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000641daed1>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000725ea6c9>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 1 lock held by rsyslogd/3503: #0: (&f->f_pos_lock){+.+.}, at: [<00000000e7a1d0ed>] __fdget_pos+0x12b/0x190 fs/file.c:770 2 locks held by getty/3625: #0: (&tty->ldisc_sem){++++}, at: [<000000007238c9dd>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ed9e3ff2>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3626: #0: (&tty->ldisc_sem){++++}, at: [<000000007238c9dd>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ed9e3ff2>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3627: #0: (&tty->ldisc_sem){++++}, at: [<000000007238c9dd>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ed9e3ff2>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3628: #0: (&tty->ldisc_sem){++++}, at: [<000000007238c9dd>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ed9e3ff2>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3629: #0: (&tty->ldisc_sem){++++}, at: [<000000007238c9dd>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ed9e3ff2>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3630: #0: (&tty->ldisc_sem){++++}, at: [<000000007238c9dd>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ed9e3ff2>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3631: #0: (&tty->ldisc_sem){++++}, at: [<000000007238c9dd>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ed9e3ff2>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 1 lock held by blkid/21659: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000a31b7574>] __blkdev_put+0xbc/0x7f0 fs/block_dev.c:1757 1 lock held by syz-executor1/3709: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002c66219b>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:2145 1 lock held by syz-executor1/3721: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002c66219b>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:2145 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 746 Comm: khungtaskd Not tainted 4.15.0-rc8+ #180 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+0x3a/0x50 arch/x86/entry/entry_64.S:541 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54