============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.13/5990 is trying to acquire lock:
ffff888034d95378 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453

but task is already holding lock:
ffff888062492df8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x215/0x1d70 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.0.13/5990:
 #0: ffff888037360480 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff888062493058 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1033 [inline]
 #1: ffff888062493058 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63
 #2: ffff888062492df8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453
 #3: ffff8880360000a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28

stack backtrace:
CPU: 0 UID: 0 PID: 5990 Comm: syz.0.13 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+0x253f/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0xf0/0x2e0 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_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453
 hfsplus_bmap_reserve+0x128/0x520 fs/hfsplus/btree.c:358
 __hfsplus_ext_write_extent+0x2b0/0x5e0 fs/hfsplus/extents.c:104
 __hfsplus_ext_cache_extent+0x9b/0x780 fs/hfsplus/extents.c:186
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x4af/0x1d70 fs/hfsplus/extents.c:457
 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142
 block_write_begin fs/buffer.c:2253 [inline]
 cont_write_begin+0x737/0xae0 fs/buffer.c:2591
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 cont_expand_zero fs/buffer.c:2519 [inline]
 cont_write_begin+0x2e7/0xae0 fs/buffer.c:2581
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2482
 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280
 notify_change+0xc18/0xf60 fs/attr.c:556
 do_truncate+0x1c2/0x250 fs/open.c:68
 vfs_truncate+0x4b7/0x540 fs/open.c:118
 do_sys_truncate+0xf3/0x1c0 fs/open.c:142
 __do_sys_truncate fs/open.c:154 [inline]
 __se_sys_truncate fs/open.c:152 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:152
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feef643c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feef468e028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007feef66b5fa0 RCX: 00007feef643c799
RDX: 0000000000000000 RSI: 0000000002fffffd RDI: 0000200000000940
RBP: 00007feef64d2bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feef66b6038 R14: 00007feef66b5fa0 R15: 00007ffd37078178
 </TASK>