hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: fs/hfs/bnode.c:520 at hfs_bnode_create+0x461/0x4f0, CPU#1: kworker/u10:0/27
Modules linked in:
CPU: 1 UID: 0 PID: 27 Comm: kworker/u10:0 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
Workqueue: writeback wb_workfn (flush-7:7)
RIP: 0010:hfs_bnode_create+0x461/0x4f0
Code: 82 8b 89 ee e8 20 b1 85 fe e9 cf fc ff ff e8 e6 b7 1f ff 4c 89 ef e8 fe a4 bb 08 48 c7 c7 00 b7 82 8b 89 ee e8 00 b1 85 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:ffffc90000a26be0 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff8881a84b6000 RCX: dfa3eebf1ba6d400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc90000a26907 R09: 1ffff92000144d20
R10: dffffc0000000000 R11: fffff52000144d21 R12: 0000000000000000
R13: ffff8881a84b60e0 R14: ffff88816a67a600 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8882a9e3a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faa1a22a378 CR3: 000000011644e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x5bb/0x640
 hfs_btree_inc_height+0xf6/0xac0
 hfs_brec_insert+0x7ee/0xc80
 __hfs_ext_write_extent+0x2a1/0x470
 hfs_ext_write_extent+0x161/0x1e0
 hfs_write_inode+0xc6/0x8a0
 __writeback_single_inode+0x7e1/0x1240
 writeback_sb_inodes+0x93a/0x1870
 wb_writeback+0x42b/0xaa0
 wb_workfn+0x3f9/0xed0
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>
