loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 Not tainted
--------------------------------------------
syz-executor374/5306 is trying to acquire lock:
ffff8880439b9548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x383/0x14f0 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff8880439ba988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21b/0x1b70 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-executor374/5306:
 #0: ffff888043326420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3023 [inline]
 #0: ffff888043326420 (sb_writers#9){.+.+}-{0:0}, at: vfs_writev+0x2d6/0xbc0 fs/read_write.c:1048
 #1: ffff8880439bab78 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:865 [inline]
 #1: ffff8880439bab78 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: generic_file_write_iter+0xe0/0x5b0 mm/filemap.c:4313
 #2: ffff8880439ba988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21b/0x1b70 fs/hfsplus/extents.c:458
 #3: ffff888011df60f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x9e/0x8c0 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 0 UID: 0 PID: 5306 Comm: syz-executor374 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3039
 check_deadlock kernel/locking/lockdep.c:3091 [inline]
 validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
 hfsplus_get_block+0x383/0x14f0 fs/hfsplus/extents.c:260
 block_read_full_folio+0x3ee/0xae0 fs/buffer.c:2396
 filemap_read_folio+0x148/0x3b0 mm/filemap.c:2390
 do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3960
 do_read_cache_page mm/filemap.c:4026 [inline]
 read_cache_page+0x5b/0x170 mm/filemap.c:4035
 read_mapping_page include/linux/pagemap.h:1017 [inline]
 hfsplus_block_allocate+0xee/0x8c0 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xade/0x1b70 fs/hfsplus/extents.c:469
 hfsplus_get_block+0x406/0x14f0 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x692/0x19a0 fs/buffer.c:2116
 block_write_begin fs/buffer.c:2226 [inline]
 cont_write_begin+0x77f/0xb40 fs/buffer.c:2577
 hfsplus_write_begin+0x68/0xb0 fs/hfsplus/inode.c:46
 cont_expand_zero fs/buffer.c:2504 [inline]
 cont_write_begin+0x32b/0xb40 fs/buffer.c:2567
 hfsplus_write_begin+0x68/0xb0 fs/hfsplus/inode.c:46
 generic_perform_write+0x346/0x990 mm/filemap.c:4189
 generic_file_write_iter+0x10c/0x5b0 mm/filemap.c:4316
 do_iter_readv_writev+0x71a/0x9d0
 vfs_writev+0x38b/0xbc0 fs/read_write.c:1050
 do_pwritev fs/read_write.c:1146 [inline]
 __do_sys_pwritev2 fs/read_write.c:1204 [inline]
 __se_sys_pwritev2+0x196/0x2b0 fs/read_write.c:1195
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd7d3e11ad9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 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:00007ffef4d6efb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 0032656c69662f2e RCX: 00007fd7d3e11ad9
RDX: 0000000000000001 RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00007fd7d3e855f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000005405 R11: 0000000000000246 R12: 00007ffef4d6eff0
R13: 00007ffef4d6f218 R14: 431bde82d7b634db R15: 00007fd7d3e5a03b
 </TASK>