reiserfs: enabling write barrier flush mode
REISERFS (device loop2): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc3-syzkaller-00106-g6172a5180fcc #0 Not tainted
------------------------------------------------------
syz-executor.2/14264 is trying to acquire lock:
ffff8880307b8418 (sb_writers#17){.+.+}-{0:0}, at: reiserfs_ioctl+0x194/0x2e0 fs/reiserfs/ioctl.c:103

but task is already holding lock:
ffff88802cb31090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0x100 fs/reiserfs/lock.c:27

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sbi->lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x175/0x9d0 kernel/locking/mutex.c:747
       reiserfs_write_lock+0x79/0x100 fs/reiserfs/lock.c:27
       reiserfs_dirty_inode+0xe6/0x270 fs/reiserfs/super.c:704
       __mark_inode_dirty+0x1e0/0xd60 fs/fs-writeback.c:2452
       generic_update_time+0xcf/0xf0 fs/inode.c:1943
       inode_update_time fs/inode.c:1956 [inline]
       touch_atime+0x4eb/0x5d0 fs/inode.c:2028
       file_accessed include/linux/fs.h:2360 [inline]
       iterate_dir+0x437/0x5b0 fs/readdir.c:109
       __do_sys_getdents64 fs/readdir.c:405 [inline]
       __se_sys_getdents64 fs/readdir.c:390 [inline]
       __x64_sys_getdents64+0x14f/0x2e0 fs/readdir.c:390
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (sb_writers#17){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2433/0x3b20 kernel/locking/lockdep.c:5137
       lock_acquire kernel/locking/lockdep.c:5754 [inline]
       lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1635 [inline]
       sb_start_write include/linux/fs.h:1710 [inline]
       mnt_want_write_file+0x98/0x600 fs/namespace.c:448
       reiserfs_ioctl+0x194/0x2e0 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:871 [inline]
       __se_sys_ioctl fs/ioctl.c:857 [inline]
       __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->lock);
                               lock(sb_writers#17);
                               lock(&sbi->lock);
  rlock(sb_writers#17);

 *** DEADLOCK ***

1 lock held by syz-executor.2/14264:
 #0: ffff88802cb31090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0x100 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 3 PID: 14264 Comm: syz-executor.2 Not tainted 6.7.0-rc3-syzkaller-00106-g6172a5180fcc #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 check_noncircular+0x317/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2433/0x3b20 kernel/locking/lockdep.c:5137
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1635 [inline]
 sb_start_write include/linux/fs.h:1710 [inline]
 mnt_want_write_file+0x98/0x600 fs/namespace.c:448
 reiserfs_ioctl+0x194/0x2e0 fs/reiserfs/ioctl.c:103
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7ff23a27cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff23b07a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff23a39bf80 RCX: 00007ff23a27cae9
RDX: 0000000020000140 RSI: 0000000040087602 RDI: 0000000000000005
RBP: 00007ff23a2c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007ff23a39bf80 R15: 00007ffccc5e9aa8
 </TASK>