loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.17/4324 is trying to acquire lock:
ffff88807ce39548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x38f/0x1520 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff88807ce387c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1ca/0x1a40 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

5 locks held by syz.0.17/4324:
 #0: ffff888078c5e0e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
 #1: ffff88802c425998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_fill_super+0x13ff/0x1e20 fs/hfsplus/super.c:574
 #2: ffff88807c6600b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
 #3: ffff88807ce387c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1ca/0x1a40 fs/hfsplus/extents.c:455
 #4: ffff88802c4258f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x92/0x8d0 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 0 PID: 4324 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 __lock_acquire+0x1247/0x7b50 kernel/locking/lockdep.c:-1
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 hfsplus_get_block+0x38f/0x1520 fs/hfsplus/extents.c:260
 block_read_full_page+0x308/0xd20 fs/buffer.c:2290
 do_read_cache_page+0x882/0x1010 mm/filemap.c:-1
 read_mapping_page include/linux/pagemap.h:515 [inline]
 hfsplus_block_allocate+0xdc/0x8d0 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xb17/0x1a40 fs/hfsplus/extents.c:466
 hfsplus_bmap_reserve+0x107/0x510 fs/hfsplus/btree.c:357
 hfsplus_create_cat+0x1bd/0x1090 fs/hfsplus/catalog.c:272
 hfsplus_fill_super+0x147d/0x1e20 fs/hfsplus/super.c:581
 mount_bdev+0x28a/0x3c0 fs/super.c:1411
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1541
 do_new_mount+0x247/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f64278563ca
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffc62cf1678 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffc62cf1700 RCX: 00007f64278563ca
RDX: 0000200000000100 RSI: 0000200000002900 RDI: 00007ffc62cf16c0
RBP: 0000200000000100 R08: 00007ffc62cf1700 R09: 0000000002000010
R10: 0000000002000010 R11: 0000000000000246 R12: 0000200000002900
R13: 00007ffc62cf16c0 R14: 00000000000006f1 R15: 0000200000000c00
 </TASK>