============================================
WARNING: possible recursive locking detected
6.13.0-rc3-next-20241220-syzkaller #0 Not tainted
--------------------------------------------
syz.9.457/9151 is trying to acquire lock:
ffff88804e69cd38 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: inode_lock include/linux/fs.h:863 [inline]
ffff88804e69cd38 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:836

but task is already holding lock:
ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: inode_lock include/linux/fs.h:863 [inline]
ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline]
ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline]
ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline]
ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_copy_up_flags+0x199a/0x4790 fs/overlayfs/copy_up.c:1257

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&sb->s_type->i_mutex_key#43);
  lock(&sb->s_type->i_mutex_key#43);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

6 locks held by syz.9.457/9151:
 #0: ffff888059562420 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:548
 #1: ffff88806f059e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:898 [inline]
 #1: ffff88806f059e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4574
 #2: ffff88806f05b570 (&ovl_i_mutex_key[depth]#2){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:863 [inline]
 #2: ffff88806f05b570 (&ovl_i_mutex_key[depth]#2){+.+.}-{4:4}, at: vfs_unlink+0xe4/0x650 fs/namei.c:4512
 #3: ffff88806f05b928 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:650 [inline]
 #3: ffff88806f05b928 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:727
 #4: ffff88805f77c420 (sb_writers#41){.+.+}-{0:0}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:781 [inline]
 #4: ffff88805f77c420 (sb_writers#41){.+.+}-{0:0}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline]
 #4: ffff88805f77c420 (sb_writers#41){.+.+}-{0:0}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline]
 #4: ffff88805f77c420 (sb_writers#41){.+.+}-{0:0}, at: ovl_copy_up_flags+0x1983/0x4790 fs/overlayfs/copy_up.c:1257
 #5: ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: inode_lock include/linux/fs.h:863 [inline]
 #5: ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline]
 #5: ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline]
 #5: ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline]
 #5: ffff88804e69be08 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: ovl_copy_up_flags+0x199a/0x4790 fs/overlayfs/copy_up.c:1257

stack backtrace:
CPU: 0 UID: 0 PID: 9151 Comm: syz.9.457 Not tainted 6.13.0-rc3-next-20241220-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
 check_deadlock kernel/locking/lockdep.c:3089 [inline]
 validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 down_write+0x99/0x220 kernel/locking/rwsem.c:1577
 inode_lock include/linux/fs.h:863 [inline]
 bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:836
 vfs_symlink+0x137/0x2e0 fs/namei.c:4669
 ovl_do_symlink+0x85/0xd0 fs/overlayfs/overlayfs.h:267
 ovl_create_real+0x346/0x550 fs/overlayfs/dir.c:206
 ovl_copy_up_workdir fs/overlayfs/copy_up.c:783 [inline]
 ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline]
 ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline]
 ovl_copy_up_flags+0x19cd/0x4790 fs/overlayfs/copy_up.c:1257
 ovl_nlink_start+0x9c/0x400 fs/overlayfs/util.c:1165
 ovl_do_remove+0x1fa/0xd90 fs/overlayfs/dir.c:920
 vfs_unlink+0x365/0x650 fs/namei.c:4523
 do_unlinkat+0x4ae/0x830 fs/namei.c:4587
 __do_sys_unlink fs/namei.c:4635 [inline]
 __se_sys_unlink fs/namei.c:4633 [inline]
 __x64_sys_unlink+0x47/0x50 fs/namei.c:4633
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff3d9585d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3d73f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007ff3d9776160 RCX: 00007ff3d9585d29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000440
RBP: 00007ff3d9601b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff3d9776160 R15: 00007fff9a3eab58
 </TASK>
syz.9.457 (9151) used greatest stack depth: 10864 bytes left