INFO: task kworker/u4:3:17110 blocked for more than 143 seconds. Not tainted 5.1.0-rc5-next-20190416 #26 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:3 D24120 17110 2 0x80000000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2876 [inline] __schedule+0x813/0x1cc0 kernel/sched/core.c:3517 schedule+0x92/0x180 kernel/sched/core.c:3561 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu+0x2dc/0x3e8 kernel/rcu/srcutree.c:999 fsnotify_connector_destroy_workfn+0x4e/0xa0 fs/notify/mark.c:177 process_one_work+0x98e/0x1790 kernel/workqueue.c:2274 worker_thread+0x98/0xe40 kernel/workqueue.c:2420 kthread+0x357/0x430 kernel/kthread.c:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task kworker/u4:5:20888 blocked for more than 143 seconds. Not tainted 5.1.0-rc5-next-20190416 #26 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:5 D24552 20888 2 0x80000000 Workqueue: events_unbound fsnotify_mark_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2876 [inline] __schedule+0x813/0x1cc0 kernel/sched/core.c:3517 schedule+0x92/0x180 kernel/sched/core.c:3561 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline] synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997 fsnotify_mark_destroy_workfn+0x110/0x3b0 fs/notify/mark.c:827 process_one_work+0x98e/0x1790 kernel/workqueue.c:2274 worker_thread+0x98/0xe40 kernel/workqueue.c:2420 kthread+0x357/0x430 kernel/kthread.c:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.3:24868 blocked for more than 144 seconds. Not tainted 5.1.0-rc5-next-20190416 #26 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28384 24868 15097 0x00000004 Call Trace: context_switch kernel/sched/core.c:2876 [inline] __schedule+0x813/0x1cc0 kernel/sched/core.c:3517 schedule+0x92/0x180 kernel/sched/core.c:3561 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline] synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997 blk_mq_quiesce_queue+0x14e/0x1d0 block/blk-mq.c:241 nbd_clear_que+0x68/0xf0 drivers/block/nbd.c:749 nbd_clear_sock drivers/block/nbd.c:1099 [inline] nbd_config_put+0x189/0x7e0 drivers/block/nbd.c:1114 nbd_release+0xf6/0x140 drivers/block/nbd.c:1379 __blkdev_put+0x4d3/0x810 fs/block_dev.c:1844 blkdev_put+0x98/0x560 fs/block_dev.c:1906 blkdev_close+0x8b/0xb0 fs/block_dev.c:1913 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4129e1 Code: bb c8 00 00 00 ff 15 1e 6e 24 00 85 c0 89 c5 0f 85 7e fc ff ff e9 32 ff ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 48 <89> 5c 24 d0 4c 89 6c 24 e8 48 89 d3 48 89 6c 24 d8 4c 89 64 24 e0 RSP: 002b:00007fff10389320 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00000000004129e1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000740e80 R08: 0000000094085a24 R09: 0000000094085a28 R10: 00007fff103893f0 R11: 0000000000000293 R12: 0000000000000001 R13: 0000000000219827 R14: 0000000000219854 R15: 000000000073bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 000000003a0bcfd4 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5056 1 lock held by rsyslogd/7625: #0: 00000000dff7a24a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7714: #0: 00000000e7210556 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003920d608 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7715: #0: 000000003a5edd04 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008befc311 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7716: #0: 0000000084a27a11 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a0fbcf95 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7717: #0: 00000000f65a574c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000458f1170 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7718: #0: 00000000b8513fd6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000072261af7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7719: #0: 00000000d82627f7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000051b51454 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7720: #0: 000000003b5081af (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000044a0eba3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by kworker/u4:3/17110: #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2245 #1: 000000004f3759c9 (connector_reaper_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2249 3 locks held by kworker/0:3/24648: 2 locks held by kworker/u4:5/20888: #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000004d1d976f ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2245 #1: 00000000a89f34ca ((reaper_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2249 2 locks held by syz-executor.3/24868: #0: 000000003ac545a0 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xbb/0x810 fs/block_dev.c:1831 #1: 00000000497f38b6 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock lib/refcount.c:319 [inline] #1: 00000000497f38b6 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock+0x56/0x90 lib/refcount.c:314 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc5-next-20190416 #26 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: