INFO: task syz-executor:6536 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:6536  tgid:6536  ppid:1      task_flags:0x400140 flags:0x00000001
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7058
 wb_wait_for_completion+0x150/0x280 fs/fs-writeback.c:216
 __writeback_inodes_sb_nr+0x1b0/0x218 fs/fs-writeback.c:2748
 writeback_inodes_sb_nr fs/fs-writeback.c:2765 [inline]
 writeback_inodes_sb+0x78/0x8c fs/fs-writeback.c:2780
 sync_filesystem+0xa0/0x218 fs/sync.c:54
 generic_shutdown_super+0x70/0x2b8 fs/super.c:622
 bch2_kill_sb+0x40/0x58 fs/bcachefs/fs.c:2618
 deactivate_locked_super+0xc4/0x12c fs/super.c:474
 deactivate_super+0xe0/0x100 fs/super.c:507
 cleanup_mnt+0x31c/0x3ac fs/namespace.c:1375
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1382
 task_work_run+0x1dc/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xfc/0x168 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
 el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:745
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Showing all locks held in the system:
2 locks held by kworker/u8:1/14:
 #0: ffff0000c1f72948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3210
 #1: ffff800097c57be0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3210
1 lock held by khungtaskd/32:
 #0: ffff80008f9c92e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
2 locks held by pr/ttyAMA-1/43:
2 locks held by getty/6311:
 #0: ffff0000d32520a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009bbce2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa4 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/6536:
 #0: ffff0000f88220e0 (&type->s_umount_key#74){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff0000f88220e0 (&type->s_umount_key#74){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff0000f88220e0 (&type->s_umount_key#74){+.+.}-{4:4}, at: deactivate_super+0xd8/0x100 fs/super.c:506
4 locks held by bch-reclaim/loo/7642:
 #0: ffff0000ed4caf68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x12c/0x480 fs/bcachefs/journal_reclaim.c:773
 #1: ffff0000ed484398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire+0x18/0x54 include/linux/srcu.h:160
 #2: ffff0000ed484740 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x1078/0x11c0 fs/bcachefs/btree_write_buffer.c:571
 #3: ffff0000ed4a6710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x468/0x1ab8 fs/bcachefs/btree_update_interior.c:1211

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