loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.17/4470 is trying to acquire lock:
ffff0000d6191548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x2c0/0x11a0 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff0000d61907c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x18c/0x13b4 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.0.17/4470:
 #0: ffff0000db0480e0 (&type->s_umount_key#50/1){+.+.}-{3:3}, at: alloc_super+0x1a4/0x800 fs/super.c:228
 #1: ffff0000d3e9e998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_fill_super+0xf10/0x1654 fs/hfsplus/super.c:572
 #2: ffff0000cf28c0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
 #3: ffff0000d61907c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x18c/0x13b4 fs/hfsplus/extents.c:455
 #4: ffff0000d3e9e8f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x88/0x7e4 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 1 PID: 4470 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call trace:
 dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 __lock_acquire+0x15cc/0x6800 kernel/locking/lockdep.c:-1
 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662
 __mutex_lock_common+0x190/0x1f60 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 hfsplus_get_block+0x2c0/0x11a0 fs/hfsplus/extents.c:260
 block_read_full_folio+0x2f4/0x980 fs/buffer.c:2271
 hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28
 filemap_read_folio+0x134/0x384 mm/filemap.c:2490
 do_read_cache_folio+0x24c/0x538 mm/filemap.c:3659
 do_read_cache_page mm/filemap.c:3701 [inline]
 read_cache_page+0x6c/0x184 mm/filemap.c:3710
 read_mapping_page include/linux/pagemap.h:793 [inline]
 hfsplus_block_allocate+0xd8/0x7e4 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0x7a0/0x13b4 fs/hfsplus/extents.c:466
 hfsplus_bmap_reserve+0xe8/0x494 fs/hfsplus/btree.c:358
 hfsplus_create_cat+0x19c/0xe24 fs/hfsplus/catalog.c:272
 hfsplus_fill_super+0xf74/0x1654 fs/hfsplus/super.c:579
 mount_bdev+0x264/0x358 fs/super.c:1443
 hfsplus_mount+0x44/0x58 fs/hfsplus/super.c:660
 legacy_get_tree+0xd4/0x16c fs/fs_context.c:632
 vfs_get_tree+0x90/0x274 fs/super.c:1573
 do_new_mount+0x228/0x810 fs/namespace.c:3078
 path_mount+0x5bc/0xe80 fs/namespace.c:3408
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount fs/namespace.c:3606 [inline]
 __arm64_sys_mount+0x49c/0x59c fs/namespace.c:3606
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
hfsplus: b-tree write err: -5, ino 25