option from the mount to silence this warning.
==========
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L      
------------------------------------------------------
syz.1.123/6063 is trying to acquire lock:
ffff8880237bd7d8 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: iterate_dir+0x287/0x880 fs/readdir.c:106

but task is already holding lock:
ffff88805ac4de58 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
ffff88805ac4de58 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: vfs_rmdir+0xf8/0x6a0 fs/namei.c:5542

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}:
       down_read+0x45/0x320 kernel/locking/rwsem.c:1574
       inode_lock_shared include/linux/fs.h:1039 [inline]
       lookup_slow+0x46/0x80 fs/namei.c:1935
       ovl_lookup_positive_unlocked fs/overlayfs/namei.c:216 [inline]
       ovl_lookup_single+0x323/0xe90 fs/overlayfs/namei.c:260
       ovl_lookup_layer+0x377/0x440 fs/overlayfs/namei.c:365
       ovl_lookup_layers fs/overlayfs/namei.c:1168 [inline]
       ovl_lookup+0x9ae/0x1c80 fs/overlayfs/namei.c:1403
       lookup_open+0x94b/0x1970 fs/namei.c:4559
       open_last_lookups fs/namei.c:4798 [inline]
       path_openat+0x673/0x1da0 fs/namei.c:5037
       do_file_open+0x23e/0x4a0 fs/namei.c:5069
       do_sys_openat2+0x115/0x200 fs/open.c:1442
       do_sys_open fs/open.c:1448 [inline]
       __do_sys_openat fs/open.c:1788 [inline]
       __se_sys_openat fs/open.c:1783 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1783
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (DCACHE_PAR_LOOKUP){+.+.}-{0:0}:
       d_wait_lookup fs/dcache.c:2840 [inline]
       __d_alloc_parallel+0xc32/0x1700 fs/dcache.c:2944
       __lookup_slow+0x82/0x2f0 fs/namei.c:1904
       lookup_slow+0x59/0x80 fs/namei.c:1936
       walk_component fs/namei.c:2311 [inline]
       link_path_walk+0xd22/0x1910 fs/namei.c:2685
       path_parentat fs/namei.c:2889 [inline]
       __filename_parentat+0x287/0x6f0 fs/namei.c:2913
       filename_parentat fs/namei.c:2931 [inline]
       filename_unlinkat+0x104/0x610 fs/namei.c:5730
       __do_sys_unlink fs/namei.c:5796 [inline]
       __se_sys_unlink+0x2e/0x140 fs/namei.c:5793
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&type->i_mutex_dir_key#5){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
       down_read_killable+0x4b/0x3b0 kernel/locking/rwsem.c:1599
       iterate_dir+0x287/0x880 fs/readdir.c:106
       ovl_dir_read+0x141/0x4a0 fs/overlayfs/readdir.c:388
       ovl_dir_read_merged+0x402/0x520 fs/overlayfs/readdir.c:461
       ovl_check_empty_dir+0xbd/0x500 fs/overlayfs/readdir.c:1083
       ovl_do_remove+0x1ad/0xdc0 fs/overlayfs/dir.c:944
       vfs_rmdir+0x3e6/0x6a0 fs/namei.c:5557
       filename_rmdir+0x292/0x520 fs/namei.c:5614
       __do_sys_unlinkat fs/namei.c:5789 [inline]
       __se_sys_unlinkat+0x71/0x1a0 fs/namei.c:5782
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &type->i_mutex_dir_key#5 --> DCACHE_PAR_LOOKUP --> &ovl_i_mutex_dir_key[depth]

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ovl_i_mutex_dir_key[depth]);
                               lock(DCACHE_PAR_LOOKUP);
                               lock(&ovl_i_mutex_dir_key[depth]);
  rlock(&type->i_mutex_dir_key#5);

 *** DEADLOCK ***

locks held by syz.1.123/6063: 3, last CPU#1:
 #0: ffff88802d47c460 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:527
 #1: ffff88805ac4e3d0 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff88805ac4e3d0 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2947 [inline]
 #1: ffff88805ac4e3d0 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2971 [inline]
 #1: ffff88805ac4e3d0 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5607
 #2: ffff88805ac4de58 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #2: ffff88805ac4de58 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: vfs_rmdir+0xf8/0x6a0 fs/namei.c:5542

stack backtrace:
CPU: 1 UID: 0 PID: 6063 Comm: syz.1.123 Tainted: G             L       syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 down_read_killable+0x4b/0x3b0 kernel/locking/rwsem.c:1599
 iterate_dir+0x287/0x880 fs/readdir.c:106
 ovl_dir_read+0x141/0x4a0 fs/overlayfs/readdir.c:388
 ovl_dir_read_merged+0x402/0x520 fs/overlayfs/readdir.c:461
 ovl_check_empty_dir+0xbd/0x500 fs/overlayfs/readdir.c:1083
 ovl_do_remove+0x1ad/0xdc0 fs/overlayfs/dir.c:944
 vfs_rmdir+0x3e6/0x6a0 fs/namei.c:5557
 filename_rmdir+0x292/0x520 fs/namei.c:5614
 __do_sys_unlinkat fs/namei.c:5789 [inline]
 __se_sys_unlinkat+0x71/0x1a0 fs/namei.c:5782
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f07d0d9e1d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f07d1caf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f07d1025fa0 RCX: 00007f07d0d9e1d9
RDX: 0000000000000200 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f07d0e35888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f07d1026038 R14: 00007f07d1025fa0 R15: 00007ffc264bc2e8
 </TASK>