INFO: task kworker/u4:4:350 blocked for more than 143 seconds. Not tainted 5.4.0-rc5-next-20191031 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:4 D24344 350 2 0x80004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 io_schedule+0x1c/0x70 kernel/sched/core.c:5788 wait_on_page_bit_common mm/filemap.c:1175 [inline] __lock_page+0x422/0xab0 mm/filemap.c:1383 lock_page include/linux/pagemap.h:480 [inline] mpage_prepare_extent_to_map+0xb3f/0xf90 fs/ext4/inode.c:2668 ext4_writepages+0x954/0x2e70 fs/ext4/inode.c:2822 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __writeback_single_inode+0x136/0x1400 fs/fs-writeback.c:1449 writeback_sb_inodes+0x596/0xf20 fs/fs-writeback.c:1713 __writeback_inodes_wb+0xc3/0x260 fs/fs-writeback.c:1782 wb_writeback+0x910/0xd90 fs/fs-writeback.c:1891 wb_check_old_data_flush fs/fs-writeback.c:1993 [inline] wb_do_writeback fs/fs-writeback.c:2046 [inline] wb_workfn+0xba5/0x1220 fs/fs-writeback.c:2075 process_one_work+0x9af/0x1740 kernel/workqueue.c:2263 worker_thread+0x98/0xe40 kernel/workqueue.c:2409 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task khugepaged:1088 blocked for more than 144 seconds. Not tainted 5.4.0-rc5-next-20191031 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D27840 1088 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 io_schedule+0x1c/0x70 kernel/sched/core.c:5788 wait_on_page_bit_common mm/filemap.c:1175 [inline] __lock_page+0x422/0xab0 mm/filemap.c:1383 lock_page include/linux/pagemap.h:480 [inline] mpage_prepare_extent_to_map+0xb3f/0xf90 fs/ext4/inode.c:2668 ext4_writepages+0x954/0x2e70 fs/ext4/inode.c:2822 ? 0xffffffff81000000 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __filemap_fdatawrite_range+0x2bc/0x3b0 mm/filemap.c:421 __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0x24/0x30 mm/filemap.c:456 collapse_file+0x36b1/0x41a0 mm/khugepaged.c:1652 khugepaged_scan_file mm/khugepaged.c:1890 [inline] khugepaged_scan_mm_slot mm/khugepaged.c:1988 [inline] khugepaged_do_scan mm/khugepaged.c:2072 [inline] khugepaged+0x2da9/0x4360 mm/khugepaged.c:2117 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 4 locks held by kworker/u4:4/350: #0: ffff8880a7e7d128 ((wq_completion)writeback){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a7e7d128 ((wq_completion)writeback){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a7e7d128 ((wq_completion)writeback){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a7e7d128 ((wq_completion)writeback){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a7e7d128 ((wq_completion)writeback){+.+.}, at: set_work_data kernel/workqueue.c:614 [inline] #0: ffff8880a7e7d128 ((wq_completion)writeback){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:641 [inline] #0: ffff8880a7e7d128 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2234 #1: ffff8880a920fdc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2238 #2: ffff88809b2320d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 fs/super.c:418 #3: ffff88809b234990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 1 lock held by khungtaskd/1081: #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by khugepaged/1088: #0: ffff88809b234990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 3 locks held by udevd/4003: #0: ffff8880ae934d58 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8880ae934d58 (&rq->lock){-.-.}, at: __schedule+0x266/0x1e70 kernel/sched/core.c:4018 #1: ffff88806e20dc80 (&of->mutex){+.+.}, at: kernfs_fop_write+0x1bc/0x4a0 fs/kernfs/file.c:306 #2: ffff8880a3460708 (kn->count#2){++++}, at: kernfs_fop_write+0x1df/0x4a0 fs/kernfs/file.c:307 1 lock held by rsyslogd/8625: #0: ffff88809bdd13e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8714: #0: ffff8880a4376090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8715: #0: ffff8880985bc090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8716: #0: ffff888099341090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f3d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8717: #0: ffff888096504090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f492e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8718: #0: ffff8880a034a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8719: #0: ffff888090c6e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8720: #0: ffff88809b273090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/10730: #0: ffffffff899b90e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 4 locks held by syz-executor.3/10743: 1 lock held by syz-executor.1/10731: 1 lock held by syz-executor.1/10737: #0: ffffffff899b90e0 (rtnl_mutex){+.+.}, at: __netlink_dump_start+0x10c/0x7d0 net/netlink/af_netlink.c:2316 1 lock held by syz-executor.0/10733: #0: ffffffff88ff0980 (event_mutex){+.+.}, at: perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:241 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1081 Comm: khungtaskd Not tainted 5.4.0-rc5-next-20191031 #0 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+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:269 [inline] watchdog+0xc8f/0x1350 kernel/hung_task.c:353 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4003 Comm: udevd Not tainted 5.4.0-rc5-next-20191031 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x1b/0x20 kernel/kcov.c:177 Code: 4d 08 e8 18 ff ff ff 5d c3 66 0f 1f 44 00 00 55 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 48 89 e5 48 8b 4d 08 e8 f6 fe ff ff 5d 0f 1f 40 00 55 0f b7 d6 0f b7 f7 bf 03 00 00 00 48 89 e5 48 8b RSP: 0018:ffff888095c57558 EFLAGS: 00000093 RAX: 0000000000000000 RBX: ffffffff87acd365 RCX: ffffffff875376ac RDX: 000000000000002e RSI: 0000000000000025 RDI: 0000000000000001 RBP: ffff888095c57610 R08: ffff888095c4c000 R09: ffffed1012b8af0f R10: ffffed1012b8af0e R11: ffff888095c57870 R12: ffff888095c57690 R13: dffffc0000000000 R14: ffff888095c575e8 R15: 000000000000002e FS: 00007f8b498107a0(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8b49817000 CR3: 0000000096364000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x17e/0x19a0 lib/vsprintf.c:2508 sprintf+0xc0/0x100 lib/vsprintf.c:2758 print_time kernel/printk/printk.c:1271 [inline] print_prefix kernel/printk/printk.c:1297 [inline] msg_print_text+0x535/0x5c0 kernel/printk/printk.c:1316 console_unlock+0x38d/0xf00 kernel/printk/printk.c:2448 vprintk_emit+0x2a0/0x700 kernel/printk/printk.c:1996 vprintk_default+0x28/0x30 kernel/printk/printk.c:2023 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:386 printk+0xba/0xed kernel/printk/printk.c:2056 fill_kobj_path lib/kobject.c:160 [inline] kobject_get_path.cold+0x38/0x47 lib/kobject.c:182 kobject_uevent_env+0x3ab/0x1023 lib/kobject_uevent.c:528 kobject_synth_uevent.cold+0xa0/0x10a lib/kobject_uevent.c:208 uevent_store+0x25/0x60 drivers/base/core.c:1421 dev_attr_store+0x57/0x80 drivers/base/core.c:1124 sysfs_kf_write+0x116/0x170 fs/sysfs/file.c:138 kernfs_fop_write+0x270/0x4a0 fs/kernfs/file.c:315 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f8b48f18370 Code: 73 01 c3 48 8b 0d c8 4a 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d 85 a2 2b 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 0e 8a 01 00 48 89 04 24 RSP: 002b:00007ffc010c8d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001a68ac0 RCX: 00007f8b48f18370 RDX: 0000000000000006 RSI: 000000000041f4f9 RDI: 000000000000000b RBP: 0000000001a68600 R08: 000000000041f4f1 R09: 00007f8b48f6e7d0 R10: 7269762f73656369 R11: 0000000000000246 R12: 000000000000000b R13: 0000000000000000 R14: 0000000001a68ac0 R15: 0000000001a67250