INFO: task kworker/u4:8:4240 blocked for more than 144 seconds.
      Not tainted 5.15.167-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:8    state:D stack:    0 pid: 4240 ppid:     2 flags:0x00000008
Workqueue: writeback wb_workfn (flush-7:0)
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6373
 schedule+0x11c/0x1c8 kernel/sched/core.c:6456
 rwsem_down_write_slowpath+0xd94/0x17e0 kernel/locking/rwsem.c:1165
 __down_write_common kernel/locking/rwsem.c:1292 [inline]
 __down_write kernel/locking/rwsem.c:1301 [inline]
 down_write+0xe8/0x12c kernel/locking/rwsem.c:1552
 f2fs_balance_fs+0x3e8/0x6a0 fs/f2fs/segment.c:528
 f2fs_write_inode+0x42c/0x4a0 fs/f2fs/inode.c:736
 write_inode fs/fs-writeback.c:1495 [inline]
 __writeback_single_inode+0x584/0x13a4 fs/fs-writeback.c:1705
 writeback_sb_inodes+0x94c/0x1654 fs/fs-writeback.c:1930
 __writeback_inodes_wb+0x110/0x39c fs/fs-writeback.c:2001
 wb_writeback+0x410/0xfc8 fs/fs-writeback.c:2106
 wb_check_background_flush fs/fs-writeback.c:2172 [inline]
 wb_do_writeback fs/fs-writeback.c:2260 [inline]
 wb_workfn+0xc44/0x1070 fs/fs-writeback.c:2288
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014c917e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
3 locks held by kworker/u4:1/136:
2 locks held by getty/3777:
 #0: ffff0000d36d7098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001d69e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
2 locks held by kworker/u4:7/4129:
4 locks held by kworker/u4:8/4240:
 #0: ffff0000c21d8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff800020647c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
 #2: ffff0000d75a80e0 (&type->s_umount_key#72){++++}-{3:3}, at: trylock_super+0x28/0xf8 fs/super.c:418
 #3: ffff0000d7455108 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3e8/0x6a0 fs/f2fs/segment.c:528
4 locks held by syz.0.101/4575:
1 lock held by syz.2.714/7429:
2 locks held by syz.4.725/7466:
3 locks held by syz.3.727/7479:
2 locks held by syz.1.728/7484:
 #0: ffff0000d549e0e0 (&type->s_umount_key#58/1){+.+.}-{3:3}, at: alloc_super+0x1b8/0x844 fs/super.c:229
 #1: ffff800014d1bc48 (lock#3){+.+.}-{3:3}, at: __lru_add_drain_all+0x88/0x9d0 mm/swap.c:782

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