loop2: detected capacity change from 0 to 64
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.2.24/6064 is trying to acquire lock:
ffff8881251000f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1230

but task is already holding lock:
ffff888125100778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1230

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

5 locks held by syz.2.24/6064:
 #0: ffff88810a722428 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888125100fa0 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: path_openat+0x8da/0x3830
 #2: ffff88810f3ce0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfs_find_init+0x184/0x200
 #3: ffff888125100778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1230
 #4: ffff88810f3cc0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x184/0x200

stack backtrace:
CPU: 1 UID: 0 PID: 6064 Comm: syz.2.24 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_deadlock_bug+0x28b/0x2a0
 validate_chain+0x1a3f/0x2140
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 __mutex_lock+0x187/0x1350
 hfs_extend_file+0xda/0x1230
 hfs_bmap_reserve+0x107/0x430
 __hfs_ext_write_extent+0x1fa/0x470
 __hfs_ext_cache_extent+0x6b/0x9b0
 hfs_extend_file+0x316/0x1230
 hfs_bmap_reserve+0x107/0x430
 hfs_cat_create+0x1b3/0x640
 hfs_create+0x66/0xe0
 path_openat+0x14f4/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29e278ebe9
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:00007f29e3582038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f29e29b5fa0 RCX: 00007f29e278ebe9
RDX: 0000000000000042 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f29e2811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001ff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f29e29b6038 R14: 00007f29e29b5fa0 R15: 00007ffe13e5bcc8
 </TASK>
hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6064 at fs/hfs/bnode.c:520 hfs_bnode_create+0x461/0x4f0
Modules linked in:
CPU: 1 UID: 0 PID: 6064 Comm: syz.2.24 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:hfs_bnode_create+0x461/0x4f0
Code: a1 8b 89 ee e8 c0 da 8d fe e9 cf fc ff ff e8 a6 e6 25 ff 4c 89 ef e8 1e 78 e2 08 48 c7 c7 e0 cd a1 8b 89 ee e8 a0 da 8d fe 90 <0f> 0b 90 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c d6 fb ff ff
RSP: 0018:ffffc900069d7040 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff88810f3cc000 RCX: 4ce4381655ae8500
RDX: ffffc9000f3f1000 RSI: 00000000000211d3 RDI: 00000000000211d4
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1ec R12: 0000000000000000
R13: ffff88810f3cc0e0 R14: ffff88801da97400 R15: dffffc0000000000
FS:  00007f29e35826c0(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557aac85c8 CR3: 0000000028938000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x5bb/0x640
 hfs_btree_inc_height+0xf6/0xac0
 hfs_brec_insert+0x743/0xbd0
 __hfs_ext_write_extent+0x2a1/0x470
 __hfs_ext_cache_extent+0x6b/0x9b0
 hfs_extend_file+0x316/0x1230
 hfs_bmap_reserve+0x107/0x430
 hfs_cat_create+0x1b3/0x640
 hfs_create+0x66/0xe0
 path_openat+0x14f4/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29e278ebe9
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:00007f29e3582038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f29e29b5fa0 RCX: 00007f29e278ebe9
RDX: 0000000000000042 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f29e2811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001ff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f29e29b6038 R14: 00007f29e29b5fa0 R15: 00007ffe13e5bcc8
 </TASK>
