INFO: task kworker/u4:1:11 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D
 stack:21896 pid:11    ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn
 (flush-7:0)

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
 hfsplus_cat_write_inode+0x1e3/0x820 fs/hfsplus/inode.c:590
 write_inode fs/fs-writeback.c:1470 [inline]
 __writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1687
 writeback_sb_inodes+0xad8/0x17d0 fs/fs-writeback.c:1913
 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984
 wb_writeback+0x47a/0xd00 fs/fs-writeback.c:2089
 wb_check_background_flush fs/fs-writeback.c:2155 [inline]
 wb_do_writeback fs/fs-writeback.c:2243 [inline]
 wb_workfn+0xbdd/0xec0 fs/fs-writeback.c:2270
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u4:1/11:
 #0: 
ffff88801aee9138
 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: 
ffffc90000107d00
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: 
ffff888079df80e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
 #3: ffff888079dfc0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8c92bab0 (
rcu_tasks.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: 
ffffffff8c92c2d0 (
rcu_tasks_trace.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8c92b120
 (
rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
4 locks held by kworker/u4:2/34:
 #0: 
ffff88801aee9138
 (
(wq_completion)writeback
){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000ab7d00 ((work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: 
ffff88807a7180e0
 (
&type->s_umount_key
#53){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
 #3: 
ffff8880735ce0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:3/46:
 #0: 
ffff88801aee9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000b77d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff8880768fa0e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
 #3: ffff888076f9c0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
2 locks held by getty/4025:
 #0: ffff88814cf74098
 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
4 locks held by kworker/u4:5/4434:
 #0: ffff88801aee9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003fd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff88807c1800e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
 #3: ffff8880296640b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
6 locks held by syz.0.17/4435:
4 locks held by kworker/u4:6/4436:
 #0: ffff88801aee9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc900033c7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffff88805b8c20e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
 #3: ffff88805b8c60b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
4 locks held by syz.1.18/4463:
4 locks held by syz.2.19/4485:
4 locks held by syz.3.20/4514:
3 locks held by kworker/u4:9/4520:
 #0: 
ffff8880b8e3aad8
 (
&rq->__lock
){-.-.}-{2:2}