syzbot

ntfs3(loop0): ino=19, mi_enum_attr
ntfs3(loop0): Mark volume as dirty due to NTFS errors
============================================
WARNING: possible recursive locking detected
6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 Not tainted
--------------------------------------------
syz-executor156/5819 is trying to acquire lock:
ffff88804bbe1e60 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1105 [inline]
ffff88804bbe1e60 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: mi_read+0x2d4/0x5a0 fs/ntfs3/record.c:148

but task is already holding lock:
ffff88804bb40100 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1105 [inline]
ffff88804bb40100 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_link+0xf6/0x280 fs/ntfs3/namei.c:141

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

       CPU0
       ----
  lock(&ni->ni_lock#2/5);
  lock(&ni->ni_lock#2/5);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

6 locks held by syz-executor156/5819:
 #0: ffff88807d8c4420 (sb_writers#8){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
 #1: ffff88804bbe6a68 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline]
 #1: ffff88804bbe6a68 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132
 #2: ffff88804bb40398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #2: ffff88804bb40398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: vfs_link+0x3b4/0x6e0 fs/namei.c:4838
 #3: ffff88804bbe67d0 (&ni->ni_lock#2/6){+.+.}-{4:4}, at: ni_lock_dir fs/ntfs3/ntfs_fs.h:1110 [inline]
 #3: ffff88804bbe67d0 (&ni->ni_lock#2/6){+.+.}-{4:4}, at: ntfs_link+0xdb/0x280 fs/ntfs3/namei.c:139
 #4: ffff88804bb40100 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1105 [inline]
 #4: ffff88804bb40100 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_link+0xf6/0x280 fs/ntfs3/namei.c:141
 #5: ffff88807d878128 (&wnd->rw_lock/1){+.+.}-{4:4}, at: ntfs_look_free_mft+0x163/0xd50 fs/ntfs3/fsntfs.c:571

stack backtrace:
CPU: 0 UID: 0 PID: 5819 Comm: syz-executor156 Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3042
 check_deadlock kernel/locking/lockdep.c:3094 [inline]
 validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3896
 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
 __mutex_lock_common kernel/locking/mutex.c:601 [inline]
 __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
 ni_lock fs/ntfs3/ntfs_fs.h:1105 [inline]
 mi_read+0x2d4/0x5a0 fs/ntfs3/record.c:148
 mi_format_new+0x1a3/0x610 fs/ntfs3/record.c:434
 ni_add_subrecord+0xd0/0x440 fs/ntfs3/frecord.c:321
 ntfs_look_free_mft+0x6aa/0xd50 fs/ntfs3/fsntfs.c:715
 ni_create_attr_list+0x8ff/0x13d0 fs/ntfs3/frecord.c:826
 ni_ins_attr_ext+0x43e/0xb50 fs/ntfs3/frecord.c:924
 ni_insert_attr fs/ntfs3/frecord.c:1091 [inline]
 ni_insert_resident fs/ntfs3/frecord.c:1475 [inline]
 ni_add_name+0x6df/0xc90 fs/ntfs3/frecord.c:2987
 ntfs_link_inode+0x132/0x180 fs/ntfs3/inode.c:1698
 ntfs_link+0x118/0x280 fs/ntfs3/namei.c:146
 vfs_link+0x4ea/0x6e0 fs/namei.c:4847
 do_linkat+0x272/0x560 fs/namei.c:4917
 __do_sys_link fs/namei.c:4951 [inline]
 __se_sys_link fs/namei.c:4949 [inline]
 __x64_sys_link+0x82/0x90 fs/namei.c:4949
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb608ddde19
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffeed9309c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 0000200000000080 RCX: 00007fb608ddde19
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 00002000000001c0
RBP: 0031656c69662f2e R08: 000055555860c4c0 R09: 000055555860c4c0
R10: 000055555860c4c0 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007ffeed930c18 R14: 431bde82d7b634db R15: 00007fb608e2703b
 </TASK>