hfsplus: inconsistency in B*Tree (9,1,255,1,0)
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.3.2760/19157 is trying to acquire lock:
ffff88807bf9d8c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff88807bf9b708 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990 fs/hfsplus/extents.c:455

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

       CPU0
       ----
  lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

6 locks held by syz.3.2760/19157:
 #0: ffff8880646ee420 (sb_writers#35){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508
 #1: ffff88807bf9c678 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
 #1: ffff88807bf9c678 (&sb->s_type->i_mutex_key#43){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320
 #2: ffff8880646ea0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28
 #3: ffff8880646e80b0 (&tree->tree_lock/2){+.+.}-{4:4}, at: hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28
 #4: ffff88807bf9b708 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990 fs/hfsplus/extents.c:455
 #5: ffff8880656508f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 0 UID: 0 PID: 19157 Comm: syz.3.2760 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041
 check_deadlock kernel/locking/lockdep.c:3093 [inline]
 validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/mutex.c:598 [inline]
 __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260
 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420
 filemap_read_folio+0x117/0x380 mm/filemap.c:2444
 do_read_cache_folio+0x350/0x590 mm/filemap.c:4024
 do_read_cache_page mm/filemap.c:4090 [inline]
 read_cache_page+0x5d/0x170 mm/filemap.c:4099
 read_mapping_page include/linux/pagemap.h:993 [inline]
 hfsplus_block_allocate+0xe4/0x9b0 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:466
 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358
 hfsplus_create_attr+0x1a9/0x3a0 fs/hfsplus/attributes.c:221
 __hfsplus_setxattr+0x661/0x1fe0 fs/hfsplus/xattr.c:358
 hfsplus_setxattr+0x11e/0x180 fs/hfsplus/xattr.c:436
 hfsplus_trusted_setxattr+0x40/0x60 fs/hfsplus/xattr_trusted.c:30
 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200
 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234
 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:321
 do_setxattr fs/xattr.c:636 [inline]
 filename_setxattr+0x274/0x600 fs/xattr.c:665
 path_setxattrat+0x364/0x3a0 fs/xattr.c:713
 __do_sys_setxattr fs/xattr.c:747 [inline]
 __se_sys_setxattr fs/xattr.c:743 [inline]
 __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:743
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb9b218eec9
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:00007fb9b2f44038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007fb9b23e5fa0 RCX: 00007fb9b218eec9
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000200000000100
RBP: 00007fb9b2211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb9b23e6038 R14: 00007fb9b23e5fa0 R15: 00007ffdcc0ba258
 </TASK>