INFO: task blkid:13929 blocked for more than 120 seconds. Not tainted 4.14.0-rc4+ #125 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D23368 13929 2965 0x00000004 Call Trace: context_switch kernel/sched/core.c:2790 [inline] __schedule+0x8eb/0x2080 kernel/sched/core.c:3366 schedule+0xf5/0x430 kernel/sched/core.c:3425 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3483 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xadb/0x19d0 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 blkdev_get+0x3a1/0xad0 fs/block_dev.c:1601 blkdev_open+0x1e4/0x270 fs/block_dev.c:1759 do_dentry_open+0x67f/0xd70 fs/open.c:752 vfs_open+0x107/0x230 fs/open.c:866 do_last fs/namei.c:3387 [inline] path_openat+0x1157/0x3520 fs/namei.c:3527 do_filp_open+0x25b/0x3b0 fs/namei.c:3562 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7f241faf3120 RSP: 002b:00007ffc87a14ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f241faf3120 RDX: 00007ffc87a15f34 RSI: 0000000000000000 RDI: 00007ffc87a15f34 RBP: 0000000000000086 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000234d030 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 2 locks held by khungtaskd/644: #0: (rcu_read_lock){....}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4552 1 lock held by rsyslogd/2875: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x131/0x1a0 fs/file.c:767 2 locks held by getty/2957: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2958: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2959: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2960: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2961: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2962: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2963: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 1 lock held by syz-executor7/13910: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xa7/0x7c0 fs/block_dev.c:1767 1 lock held by blkid/13929: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 1 lock held by syz-executor6/13950: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 1 lock held by syz-executor6/13958: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 1 lock held by syz-executor7/13980: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 1 lock held by syz-executor7/13983: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 644 Comm: khungtaskd Not tainted 4.14.0-rc4+ #125 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 nmi_cpu_backtrace+0x20e/0x240 lib/nmi_backtrace.c:102 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:61 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 trigger_all_cpu_backtrace include/linux/nmi.h:137 [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+0x39c/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff84d412c6