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Date:   Mon, 22 May 2023 20:33:58 -0700
Message-ID: <000000000000be039005fc540ed7@google.com>
Subject: [syzbot] [reiserfs?] INFO: task hung in flush_old_commits
From:   syzbot <syzbot+0a684c061589dcc30e51@syzkaller.appspotmail.com>
To:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        reiserfs-devel@vger.kernel.org, syzkaller-bugs@googlegroups.com
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Hello,

syzbot found the following issue on:

HEAD commit:    f1fcbaa18b28 Linux 6.4-rc2
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=16a6382e280000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3dc1cdd68141cdc3
dashboard link: https://syzkaller.appspot.com/bug?extid=0a684c061589dcc30e51
compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=163079f9280000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1239f37e280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f9e1748cceea/disk-f1fcbaa1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6dea99343621/vmlinux-f1fcbaa1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f5a93f86012d/Image-f1fcbaa1.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/f87acf2fade6/mount_1.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0a684c061589dcc30e51@syzkaller.appspotmail.com

INFO: task kworker/0:2:1599 blocked for more than 143 seconds.
      Not tainted 6.4.0-rc2-syzkaller-gf1fcbaa18b28 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2     state:D stack:0     pid:1599  ppid:2      flags:0x00000008
Workqueue: events_long flush_old_commits
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:556
 context_switch kernel/sched/core.c:5343 [inline]
 __schedule+0x1368/0x23b8 kernel/sched/core.c:6669
 schedule+0xc4/0x170 kernel/sched/core.c:6745
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6804
 __mutex_lock_common+0xbd8/0x21a0 kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799
 reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
 reiserfs_sync_fs fs/reiserfs/super.c:76 [inline]
 flush_old_commits+0x1b0/0x2b8 fs/reiserfs/super.c:111
 process_one_work+0x788/0x12d4 kernel/workqueue.c:2405
 worker_thread+0x8e0/0xfe8 kernel/workqueue.c:2552
 kthread+0x288/0x310 kernel/kthread.c:379
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/13:
 #0: 
ffff8000160810d0
 (
rcu_tasks.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:518
1 lock held by rcu_tasks_trace/14:
 #0: 
ffff800016081490
 (
rcu_tasks_trace.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:518
1 lock held by khungtaskd/28:
 #0: 
ffff800016080f00
 (
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:326
4 locks held by kworker/0:2/1599:
 #0: 
ffff0000c0021538
 (
(wq_completion)events_long
){+.+.}-{0:0}
, at: process_one_work+0x664/0x12d4 kernel/workqueue.c:2378
 #1: 
ffff800022d77c20
 (
(work_completion)(&(&sbi->old_work)->work)
){+.+.}-{0:0}
, at: process_one_work+0x6a8/0x12d4 kernel/workqueue.c:2380
 #2: 
ffff0000df14e0e0
 (
&type->s_umount_key
#40
){++++}-{3:3}
, at: flush_old_commits+0xcc/0x2b8 fs/reiserfs/super.c:97
 #3: 
ffff0000c5d07090
 (
&sbi->lock
){+.+.}-{3:3}
, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
2 locks held by getty/5732:
 #0: 
ffff0000d4c6f098
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: 
ffff80001ae302f0
 (
&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2176
7 locks held by syz-executor247/6003:

=============================================


---
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