============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.8.459/10666 is trying to acquire lock:
ffff88803ea58098 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403

but task is already holding lock:
ffff88803ea5e218 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403

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

       CPU0
       ----
  lock(&HFS_I(tree->inode)->extents_lock);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

locks held by syz.8.459/10666: 5, last CPU#0:
 #0: ffff888034462510 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:531
 #1: ffff88803ea5f0f0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff88803ea5f0f0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
 #1: ffff88803ea5f0f0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
 #1: ffff88803ea5f0f0 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5102
 #2: ffff88803aaf00a0 (&tree->tree_lock){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1
 #3: ffff88803ea5e218 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403
 #4: ffff8880344660a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 0 UID: 0 PID: 10666 Comm: syz.8.459 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3085
 check_deadlock kernel/locking/lockdep.c:3137 [inline]
 validate_chain kernel/locking/lockdep.c:3939 [inline]
 __lock_acquire+0x25db/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
 mutex_lock_nested+0x55/0x1d0 kernel/locking/rtmutex_api.c:580
 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:403
 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402
 __hfs_ext_write_extent+0x200/0x620 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:180
 hfs_ext_read_extent fs/hfs/extent.c:208 [inline]
 hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:407
 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402
 hfs_cat_create+0x23d/0x870 fs/hfs/catalog.c:104
 hfs_mkdir+0x73/0xe0 fs/hfs/dir.c:226
 vfs_mkdir+0x414/0x630 fs/namei.c:5420
 filename_mkdirat+0x289/0x520 fs/namei.c:5453
 __do_sys_mkdirat fs/namei.c:5474 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5471
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbff217f559
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:00007fbff038c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fbff2406180 RCX: 00007fbff217f559
RDX: 00000000000001ff RSI: 0000200000021e40 RDI: ffffffffffffff9c
RBP: 00007fbff2216b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbff2406218 R14: 00007fbff2406180 R15: 00007fff822f4f38
 </TASK>
hfs: new node 0 already hashed?
------------[ cut here ]------------
1
WARNING: fs/hfs/bnode.c:478 at hfs_bnode_create+0x45a/0x4e0 fs/hfs/bnode.c:478, CPU#0: syz.8.459/10666
Modules linked in:
CPU: 0 UID: 0 PID: 10666 Comm: syz.8.459 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:hfs_bnode_create+0x45a/0x4e0 fs/hfs/bnode.c:478
Code: a9 8b 89 ee e8 07 17 76 fe e9 d6 fc ff ff e8 2d 6f 15 ff 4c 89 ef e8 f5 8d ad 08 48 c7 c7 60 72 a9 8b 89 ee e8 e7 16 76 fe 90 <0f> 0b 90 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c dd fb ff ff
RSP: 0018:ffffc90006207528 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff888034466000 RCX: 9f0234ae8520a600
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000c40e55 R12: 0000000000000000
R13: ffff8880344660d0 R14: ffff8880272ca800 R15: dffffc0000000000
FS:  00007fbff038c6c0(0000) GS:ffff8881247ad000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbff21ccc40 CR3: 000000003e2f4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 hfs_btree_inc_height+0xf9/0xac0 fs/hfs/brec.c:490
 hfs_brec_insert+0x7eb/0xc80 fs/hfs/brec.c:148
 __hfs_ext_write_extent+0x34b/0x620 fs/hfs/extent.c:124
 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:180
 hfs_ext_read_extent fs/hfs/extent.c:208 [inline]
 hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:407
 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:402
 hfs_cat_create+0x23d/0x870 fs/hfs/catalog.c:104
 hfs_mkdir+0x73/0xe0 fs/hfs/dir.c:226
 vfs_mkdir+0x414/0x630 fs/namei.c:5420
 filename_mkdirat+0x289/0x520 fs/namei.c:5453
 __do_sys_mkdirat fs/namei.c:5474 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5471
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbff217f559
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:00007fbff038c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fbff2406180 RCX: 00007fbff217f559
RDX: 00000000000001ff RSI: 0000200000021e40 RDI: ffffffffffffff9c
RBP: 00007fbff2216b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbff2406218 R14: 00007fbff2406180 R15: 00007fff822f4f38
 </TASK>