=======================================================
============================================
WARNING: possible recursive locking detected
6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Not tainted
--------------------------------------------
syz-executor143/5080 is trying to acquire lock:
ffff888079211548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x383/0x14f0 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff888079213048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x21b/0x1b70 fs/hfsplus/extents.c:457

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-executor143/5080:
 #0: ffff888023fe2420 (sb_writers#9){.+.+}-{0:0}, at: do_ftruncate+0x294/0x590 fs/open.c:178
 #1: ffff888079213240 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
 #1: ffff888079213240 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: do_truncate fs/open.c:63 [inline]
 #1: ffff888079213240 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: do_ftruncate+0x457/0x590 fs/open.c:181
 #2: ffff888079213048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x21b/0x1b70 fs/hfsplus/extents.c:457
 #3: ffff88802e4330f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x9e/0x8c0 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 0 PID: 5080 Comm: syz-executor143 Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
 hfsplus_get_block+0x383/0x14f0 fs/hfsplus/extents.c:260
 block_read_full_folio+0x42e/0xe10 fs/buffer.c:2407
 filemap_read_folio+0x1a0/0x790 mm/filemap.c:2355
 do_read_cache_folio+0x134/0x820 mm/filemap.c:3788
 do_read_cache_page+0x30/0x200 mm/filemap.c:3854
 read_mapping_page include/linux/pagemap.h:888 [inline]
 hfsplus_block_allocate+0xee/0x8c0 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xade/0x1b70 fs/hfsplus/extents.c:468
 hfsplus_get_block+0x406/0x14f0 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2128
 __block_write_begin fs/buffer.c:2177 [inline]
 block_write_begin+0x9b/0x1e0 fs/buffer.c:2236
 cont_write_begin+0x645/0x890 fs/buffer.c:2590
 hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
 cont_expand_zero fs/buffer.c:2517 [inline]
 cont_write_begin+0x319/0x890 fs/buffer.c:2580
 hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
 generic_cont_expand_simple+0x18f/0x2b0 fs/buffer.c:2481
 hfsplus_setattr+0x178/0x280 fs/hfsplus/inode.c:259
 notify_change+0xb9d/0xe70 fs/attr.c:497
 do_truncate fs/open.c:65 [inline]
 do_ftruncate+0x46b/0x590 fs/open.c:181
 do_sys_ftruncate fs/open.c:199 [inline]
 __do_sys_ftruncate fs/open.c:207 [inline]
 __se_sys_ftruncate fs/open.c:205 [inline]
 __x64_sys_ftruncate+0x95/0xf0 fs/open.c:205
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a0e43e679
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdd2a91128 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007ffdd2a912f8 RCX: 00007f6a0e43e679