loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
6.1.140-syzkaller #0 Not tainted
--------------------------------------------
syz.0.27/4501 is trying to acquire lock:
ffff0000de2e9548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x2bc/0x1154 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff0000d7e28108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x180/0x1324 fs/hfsplus/extents.c:458

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

4 locks held by syz.0.27/4501:
 #0: ffff0000d3f1c460 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:393
 #1: ffff0000d7e28300 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff0000d7e28300 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: do_truncate+0x164/0x1f0 fs/open.c:63
 #2: ffff0000d7e28108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x180/0x1324 fs/hfsplus/extents.c:458
 #3: ffff0000d376e0f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x88/0x7d8 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 1 PID: 4501 Comm: syz.0.27 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 dump_backtrace+0x1c8/0x1f4 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+0xf8/0x160 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 __lock_acquire+0x18b4/0x6544 kernel/locking/lockdep.c:-1
 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662
 __mutex_lock_common+0x190/0x1f38 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+0x2bc/0x1154 fs/hfsplus/extents.c:260
 block_read_full_folio+0x2e4/0x97c fs/buffer.c:2271
 hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28
 filemap_read_folio+0x130/0x37c mm/filemap.c:2490
 do_read_cache_folio+0x24c/0x544 mm/filemap.c:3627
 do_read_cache_page mm/filemap.c:3669 [inline]
 read_cache_page+0x6c/0x184 mm/filemap.c:3678
 read_mapping_page include/linux/pagemap.h:791 [inline]
 hfsplus_block_allocate+0xdc/0x7d8 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0x73c/0x1324 fs/hfsplus/extents.c:469
 hfsplus_get_block+0x314/0x1154 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x34c/0x13b8 fs/buffer.c:1991
 __block_write_begin fs/buffer.c:2041 [inline]
 block_write_begin fs/buffer.c:2102 [inline]
 cont_write_begin+0x548/0x780 fs/buffer.c:2456
 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52
 cont_expand_zero fs/buffer.c:2383 [inline]
 cont_write_begin+0x268/0x780 fs/buffer.c:2446
 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52
 generic_cont_expand_simple+0x12c/0x1fc fs/buffer.c:2347
 hfsplus_setattr+0x148/0x258 fs/hfsplus/inode.c:263
 notify_change+0xb0c/0xdcc fs/attr.c:499
 do_truncate+0x178/0x1f0 fs/open.c:65
 vfs_truncate+0x23c/0x2b0 fs/open.c:111
 do_sys_truncate+0xe8/0x1b0 fs/open.c:134
 __do_sys_truncate fs/open.c:146 [inline]
 __se_sys_truncate fs/open.c:144 [inline]
 __arm64_sys_truncate+0x5c/0x70 fs/open.c:144
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 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