syzbot

loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 Not tainted
--------------------------------------------
syz-executor113/5835 is trying to acquire lock:
ffff888034c51548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff888034c52988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x294/0xb40 fs/hfsplus/extents.c:577

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-executor113/5835:
 #0: ffff8880293e8428 (sb_writers#8){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff888034c52b78 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:874 [inline]
 #1: ffff888034c52b78 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
 #2: ffff888034c52988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x294/0xb40 fs/hfsplus/extents.c:577
 #3: ffff8880283338f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_free+0xbe/0x550 fs/hfsplus/bitmap.c:182

stack backtrace:
CPU: 0 UID: 0 PID: 5835 Comm: syz-executor113 Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3044
 check_deadlock kernel/locking/lockdep.c:3096 [inline]
 validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3898
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 __mutex_lock_common kernel/locking/mutex.c:602 [inline]
 __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747
 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260
 block_read_full_folio+0x29c/0x830 fs/buffer.c:2427
 filemap_read_folio+0x114/0x380 mm/filemap.c:2412
 do_read_cache_folio+0x350/0x590 mm/filemap.c:3894
 do_read_cache_page mm/filemap.c:3960 [inline]
 read_cache_page+0x5d/0x170 mm/filemap.c:3969
 read_mapping_page include/linux/pagemap.h:966 [inline]
 hfsplus_block_free+0x121/0x550 fs/hfsplus/bitmap.c:185
 hfsplus_free_extents+0x176/0xae0 fs/hfsplus/extents.c:363
 hfsplus_file_truncate+0x736/0xb40 fs/hfsplus/extents.c:592
 hfsplus_setattr+0x1c4/0x270 fs/hfsplus/inode.c:264
 notify_change+0xb33/0xe40 fs/attr.c:552
 do_truncate+0x1a4/0x220 fs/open.c:68
 handle_truncate fs/namei.c:3517 [inline]
 do_open fs/namei.c:3900 [inline]
 path_openat+0x306c/0x3830 fs/namei.c:4055
 do_filp_open+0x1fa/0x410 fs/namei.c:4082
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_creat fs/open.c:1530 [inline]
 __se_sys_creat fs/open.c:1524 [inline]
 __x64_sys_creat+0x8f/0xc0 fs/open.c:1524
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6f4914e9f9
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:00007fff21b4ceb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f6f4919705e RCX: 00007f6f4914e9f9
RDX: 00007f6f4914da91 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 0000200000000000 R08: 00000000000005ee R09: 0000000000000000
R10: 00007fff21b4cd80 R11: 0000000000000246 R12: 0031656c69662f2e
R13: 00007fff21b4d098 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
hfsplus: unable to mark blocks fre