loop4: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.4.1885/13728 is trying to acquire lock:
ffff88802f119548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x393/0x1520 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff88802f1187c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x213/0x1af0 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.4.1885/13728:
 #0: ffff88803138a0e0 (&type->s_umount_key#98){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88803138a0e0 (&type->s_umount_key#98){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88803138a0e0 (&type->s_umount_key#98){+.+.}-{3:3}, at: mount_bdev+0x1da/0x2c0 fs/super.c:1649
 #1: ffff888031f94198 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_fill_super+0x1403/0x1e20 fs/hfsplus/super.c:574
 #2: ffff88805edec0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
 #3: ffff88802f1187c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x213/0x1af0 fs/hfsplus/extents.c:455
 #4: ffff888031f940f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x92/0x900 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 1 PID: 13728 Comm: syz.4.1885 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x6809/0x7d80 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
 hfsplus_get_block+0x393/0x1520 fs/hfsplus/extents.c:260
 block_read_full_folio+0x47b/0xff0 fs/buffer.c:2406
 filemap_read_folio+0x16b/0x790 mm/filemap.c:2420
 do_read_cache_folio+0x485/0x7f0 mm/filemap.c:3809
 do_read_cache_page+0x32/0x260 mm/filemap.c:3875
 read_mapping_page include/linux/pagemap.h:892 [inline]
 hfsplus_block_allocate+0xe7/0x900 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xb92/0x1af0 fs/hfsplus/extents.c:466
 hfsplus_bmap_reserve+0x10b/0x510 fs/hfsplus/btree.c:358
 hfsplus_create_cat+0x1c1/0x1070 fs/hfsplus/catalog.c:272
 hfsplus_fill_super+0x1481/0x1e20 fs/hfsplus/super.c:581
 mount_bdev+0x21c/0x2c0 fs/super.c:1651
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1772
 do_new_mount+0x24a/0xa40 fs/namespace.c:3386
 do_mount fs/namespace.c:3726 [inline]
 __do_sys_mount fs/namespace.c:3935 [inline]
 __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdd5bd9f3ca
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:00007fdd5cc43e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fdd5cc43ee0 RCX: 00007fdd5bd9f3ca
RDX: 0000200000000100 RSI: 0000200000002900 RDI: 00007fdd5cc43ea0
RBP: 0000200000000100 R08: 00007fdd5cc43ee0 R09: 0000000002000010
R10: 0000000002000010 R11: 0000000000000246 R12: 0000200000002900
R13: 00007fdd5cc43ea0 R14: 00000000000006f1 R15: 0000200000000c00
 </TASK>