syzbot

hfs: continuing without an alternate MDB
============================================
WARNING: possible recursive locking detected
6.14.0-rc4-syzkaller-00278-gece144f151ac #0 Not tainted
--------------------------------------------
syz-executor332/5823 is trying to acquire lock:
ffff888059e820b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x16e/0x1f0

but task is already holding lock:
ffff888059e820b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x16e/0x1f0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&tree->tree_lock/1);
  lock(&tree->tree_lock/1);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

5 locks held by syz-executor332/5823:
 #0: ffff888059ed6420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547
 #1: ffff888058799620 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
 #1: ffff888058799620 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: do_truncate+0x20c/0x310 fs/open.c:63
 #2: ffff888058799478 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xff/0x13e0 fs/hfs/extent.c:397
 #3: ffff888059e820b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x16e/0x1f0
 #4: ffff8880587980f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xff/0x13e0 fs/hfs/extent.c:397

stack backtrace:
CPU: 0 UID: 0 PID: 5823 Comm: syz-executor332 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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
 hfs_find_init+0x16e/0x1f0
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x31b/0x13e0 fs/hfs/extent.c:401
 hfs_bmap_reserve+0xd9/0x400 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x22e/0x4f0 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6a/0x990 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x344/0x13e0 fs/hfs/extent.c:401
 hfs_get_block+0x3e4/0xb60 fs/hfs/extent.c:353
 __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
 hfs_write_begin+0x68/0xb0 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2504 [inline]
 cont_write_begin+0x32b/0xb40 fs/buffer.c:2567
 hfs_write_begin+0x68/0xb0 fs/hfs/inode.c:52
 hfs_file_truncate+0x1ed/0xa20 fs/hfs/extent.c:494
 hfs_inode_setattr+0x458/0x620 fs/hfs/inode.c:654
 notify_change+0xbca/0xe90 fs/attr.c:552
 do_truncate+0x220/0x310 fs/open.c:65
 vfs_truncate+0x492/0x530 fs/open.c:115
 do_sys_truncate+0xdb/0x190 fs/open.c:138
 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: 0033:0x7fc55b0419f9
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:00007ffc8ccb0058 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007fc55b0419f9
RDX: 00007fc55b0419f9 RSI: 00000000087ffffe RDI: 0000400000000080
RBP: 00007fc55b08a05e R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000002f8 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc8ccb0238 R14: 0000000000000001 R15: 0000000000000001
 </TASK>