INFO: task kworker/u4:5:3076 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:20784 pid: 3076 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 hfsplus_cat_write_inode+0x210/0x8d0 fs/hfsplus/inode.c:613 write_inode fs/fs-writeback.c:1505 [inline] __writeback_single_inode+0x6c4/0xda0 fs/fs-writeback.c:1715 writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011 wb_writeback+0x45e/0xbc0 fs/fs-writeback.c:2116 wb_check_background_flush fs/fs-writeback.c:2182 [inline] wb_do_writeback fs/fs-writeback.c:2270 [inline] wb_workfn+0xbd6/0xf20 fs/fs-writeback.c:2298 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff8880195e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff888022a620e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88802b8540b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 1 lock held by khungtaskd/27: #0: ffffffff8c31ef20 ( rcu_read_lock ){....}-{1:2} , at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:1/144: #0: ffff8880195e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000168fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff8880260ee0e0 (&type->s_umount_key#54){.+.+}-{3:3} , at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff8880782940b0 ( &tree->tree_lock ){+.+.}-{3:3} , at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 4 locks held by kworker/u4:2/154: #0: ffff8880195e0138 ( (wq_completion)writeback ){+.+.}-{0:0} , at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90001fa7d00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff8880241560e0 ( &type->s_umount_key #54 ){.+.+}-{3:3} , at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff8880230d40b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 4 locks held by kworker/u4:3/155: #0: ffff8880195e0138 ( (wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90001fb7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff88801bff40e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff8880249620b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 2 locks held by kworker/0:3/1325: #0: ffff888016c72138 ( (wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90005077d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 4 locks held by kworker/u4:5/3076: #0: ffff8880195e0138