syzbot

loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
6.15.0-rc7-syzkaller-00002-gb36ddb9210e6 #0 Not tainted
--------------------------------------------
syz-executor143/5823 is trying to acquire lock:
ffff888063d807c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff888063d81c08 (&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-executor143/5823:
 #0: ffff88807d434420 (sb_writers#8){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
 #1: ffff888063d81df8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff888063d81df8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: do_truncate+0x186/0x220 fs/open.c:63
 #2: ffff888063d81c08 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x294/0xb40 fs/hfsplus/extents.c:577
 #3: ffff888027e210f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_free+0xc3/0x4c0 fs/hfsplus/bitmap.c:182

stack backtrace:
CPU: 0 UID: 0 PID: 5823 Comm: syz-executor143 Not tainted 6.15.0-rc7-syzkaller-00002-gb36ddb9210e6 #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:3042
 check_deadlock kernel/locking/lockdep.c:3094 [inline]
 validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3896
 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
 __mutex_lock_common kernel/locking/mutex.c:601 [inline]
 __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260
 block_read_full_folio+0x29f/0x830 fs/buffer.c:2425
 filemap_read_folio+0x117/0x380 mm/filemap.c:2401
 do_read_cache_folio+0x354/0x590 mm/filemap.c:3885
 do_read_cache_page mm/filemap.c:3951 [inline]
 read_cache_page+0x5d/0x170 mm/filemap.c:3960
 read_mapping_page include/linux/pagemap.h:989 [inline]
 hfsplus_block_free+0x12c/0x4c0 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+0xb36/0xe40 fs/attr.c:552
 do_truncate+0x19a/0x220 fs/open.c:65
 handle_truncate fs/namei.c:3501 [inline]
 do_open fs/namei.c:3884 [inline]
 path_openat+0x306c/0x3830 fs/namei.c:4039
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1455
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93421aba99
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:00007fff6d28a648 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f93421aba99
RDX: 0000000078841291 RSI: 0000200000000000 RDI: 00000000ffffff9c
RBP: 0031656c69662f2e R08: 0000000000000688 R09: 000055557ad734c0
R10: 00000000000000c0 R11: 0000000000000246 R12: 00007fff6d28a670
R13: 00007fff6d28a898 R14: 431bde82d7b634db R15: 00007f93421f403b
 </TASK>
hfsplus: request for non-existent node 16777216 in B*Tree
hfsplus: request for non-existent node 16777216 in B*Tree
hfsplus: request for non-existent node 16777216 in B*Tree
hfsplus: request for non-existent node 16777216 in B*Tree
hfsplus: request for non-existent node 16777216 in B*Tree
hfsplus: request for non-existent node 16777216 in B*Tree
hfsplus: unable to mark blocks free: error -5
hfsplus: can't free extent