============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.6.965/14407 is trying to acquire lock:
ffff88802a68d378 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39a/0x1600 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff88802a689ef8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1f8/0x1c40 fs/hfsplus/extents.c:453

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.6.965/14407:
 #0: ffff888038994480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
 #1: ffff88802a68a158 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1032 [inline]
 #1: ffff88802a68a158 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
 #2: ffff88802a689ef8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1f8/0x1c40 fs/hfsplus/extents.c:453
 #3: ffff8880762940e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa7/0xd10 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 1 UID: 0 PID: 14407 Comm: syz.6.965 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
 check_deadlock kernel/locking/lockdep.c:3093 [inline]
 validate_chain kernel/locking/lockdep.c:3895 [inline]
 __lock_acquire+0x2540/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
 hfsplus_get_block+0x39a/0x1600 fs/hfsplus/extents.c:260
 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420
 filemap_read_folio+0x117/0x380 mm/filemap.c:2496
 do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4096
 do_read_cache_page mm/filemap.c:4162 [inline]
 read_cache_page+0x5d/0x170 mm/filemap.c:4171
 read_mapping_page include/linux/pagemap.h:1011 [inline]
 hfsplus_block_allocate+0xf3/0xd10 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xa9a/0x1c40 fs/hfsplus/extents.c:464
 hfsplus_get_block+0x40c/0x1600 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
 block_write_begin fs/buffer.c:2256 [inline]
 cont_write_begin+0x78c/0xb50 fs/buffer.c:2594
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 cont_expand_zero fs/buffer.c:2522 [inline]
 cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 generic_cont_expand_simple+0x13f/0x210 fs/buffer.c:2485
 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280
 notify_change+0xc18/0xf60 fs/attr.c:546
 do_truncate+0x1a4/0x220 fs/open.c:68
 vfs_truncate+0x493/0x520 fs/open.c:118
 do_sys_truncate+0xdb/0x190 fs/open.c:141
 __do_sys_truncate fs/open.c:153 [inline]
 __se_sys_truncate fs/open.c:151 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:151
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe1df07f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe1dd2e6038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fe1df2d5fa0 RCX: 00007fe1df07f749
RDX: 0000000000000000 RSI: 0000000003000000 RDI: 0000200000000900
RBP: 00007fe1df103f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe1df2d6038 R14: 00007fe1df2d5fa0 R15: 00007fff7a19ba38
 </TASK>
hfsplus: invalid file type 00355 for inode 17
hfsplus: invalid file type 00355 for inode 17
hfsplus: invalid file type 00355 for inode 17