============================================
WARNING: possible recursive locking detected
6.13.0-syzkaller-00918-g95ec54a420b8 #0 Not tainted
--------------------------------------------
syz.1.2/5924 is trying to acquire lock:
ffff888057df88e0 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline]
ffff888057df88e0 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:839

but task is already holding lock:
ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline]
ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline]
ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline]
ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline]
ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_copy_up_flags+0x19c0/0x47b0 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#25);
  lock(&sb->s_type->i_mutex_key#25);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

6 locks held by syz.1.2/5924:
 #0: ffff8880626d0420 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547
 #1: ffff88805f6d46c8 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:867 [inline]
 #1: ffff88805f6d46c8 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: filename_create+0x260/0x540 fs/namei.c:4080
 #2: ffff888057cf0cf8 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline]
 #2: ffff888057cf0cf8 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: vfs_link+0x3b2/0x6e0 fs/namei.c:4784
 #3: ffff888057cf10b0 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:650 [inline]
 #3: ffff888057cf10b0 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:727
 #4: ffff888035b32420 (sb_writers#17){.+.+}-{0:0}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:781 [inline]
 #4: ffff888035b32420 (sb_writers#17){.+.+}-{0:0}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline]
 #4: ffff888035b32420 (sb_writers#17){.+.+}-{0:0}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline]
 #4: ffff888035b32420 (sb_writers#17){.+.+}-{0:0}, at: ovl_copy_up_flags+0x19a9/0x47b0 fs/overlayfs/copy_up.c:1257
 #5: ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline]
 #5: ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline]
 #5: ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline]
 #5: ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline]
 #5: ffff88805f743e08 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: ovl_copy_up_flags+0x19c0/0x47b0 fs/overlayfs/copy_up.c:1257

stack backtrace:
CPU: 0 UID: 0 PID: 5924 Comm: syz.1.2 Not tainted 6.13.0-syzkaller-00918-g95ec54a420b8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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:832 [inline]
 bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:839
 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+0x19f3/0x47b0 fs/overlayfs/copy_up.c:1257
 ovl_link+0x85/0x320 fs/overlayfs/dir.c:730
 vfs_link+0x4f0/0x6e0 fs/namei.c:4793
 do_linkat+0x555/0x6f0 fs/namei.c:4863
 __do_sys_link fs/namei.c:4897 [inline]
 __se_sys_link fs/namei.c:4895 [inline]
 __x64_sys_link+0x82/0x90 fs/namei.c:4895
 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: 0033:0x7fd63e785d29
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:00007fd63f5d3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007fd63e975fa0 RCX: 00007fd63e785d29
RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000020000280
RBP: 00007fd63e801b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd63e975fa0 R15: 00007ffe99b6aa68
 </TASK>
syz.1.2 (5924) used greatest stack depth: 12920 bytes left