============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.3.80/6321 is trying to acquire lock:
ffff888029940d98 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397

but task is already holding lock:
ffff888029940718 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397

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.3.80/6321: 5, last CPU#1:
 #0: ffff88802bec0510 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff888029940270 (&type->i_mutex_dir_key#19/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff888029940270 (&type->i_mutex_dir_key#19/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
 #1: ffff888029940270 (&type->i_mutex_dir_key#19/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
 #1: ffff888029940270 (&type->i_mutex_dir_key#19/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5092
 #2: ffff888065dda0a0 (&tree->tree_lock#2){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1
 #3: ffff888029940718 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397
 #4: ffff888065ddc0a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 1 UID: 0 PID: 6321 Comm: syz.3.80 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3057
 check_deadlock kernel/locking/lockdep.c:3109 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x261c/0x2e40 kernel/locking/lockdep.c:5254
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
 __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578
 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397
 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399
 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:401
 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399
 hfs_cat_create+0x23d/0x870 fs/hfs/catalog.c:104
 hfs_mkdir+0x73/0xe0 fs/hfs/dir.c:226
 vfs_mkdir+0x408/0x620 fs/namei.c:5410
 filename_mkdirat+0x289/0x520 fs/namei.c:5443
 __do_sys_mkdirat fs/namei.c:5464 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5461
 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: 0033:0x7f53d9eae159
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:00007f53d8106028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f53da135fa0 RCX: 00007f53d9eae159
RDX: 00000000000001ff RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f53d9f45024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f53da136038 R14: 00007f53da135fa0 R15: 00007fff15781e28
 </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#1: syz.3.80/6321
Modules linked in:
CPU: 1 UID: 0 PID: 6321 Comm: syz.3.80 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:hfs_bnode_create+0x45a/0x4e0 fs/hfs/bnode.c:478
Code: 89 8b 89 ee e8 07 2d 78 fe e9 d6 fc ff ff e8 dd 3a 17 ff 4c 89 ef e8 e5 72 a8 08 48 c7 c7 80 48 89 8b 89 ee e8 e7 2c 78 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:ffffc900063b7548 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff888065ddc000 RCX: b99fc9f8f503e200
RDX: ffffc9000f491000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000c76e55 R12: 0000000000000000
R13: ffff888065ddc0d0 R14: ffff8880410ed400 R15: dffffc0000000000
FS:  00007f53d81066c0(0000) GS:ffff888125cd6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000018000 CR3: 000000003b966000 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+0x2a3/0x470 fs/hfs/extent.c:124
 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:401
 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399
 hfs_cat_create+0x23d/0x870 fs/hfs/catalog.c:104
 hfs_mkdir+0x73/0xe0 fs/hfs/dir.c:226
 vfs_mkdir+0x408/0x620 fs/namei.c:5410
 filename_mkdirat+0x289/0x520 fs/namei.c:5443
 __do_sys_mkdirat fs/namei.c:5464 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5461
 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: 0033:0x7f53d9eae159
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:00007f53d8106028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f53da135fa0 RCX: 00007f53d9eae159
RDX: 00000000000001ff RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f53d9f45024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f53da136038 R14: 00007f53da135fa0 R15: 00007fff15781e28
 </TASK>