hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: fs/hfs/bnode.c:520 at hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520, CPU#0: kworker/u9:0/26
Modules linked in:
CPU: 0 UID: 0 PID: 26 Comm: kworker/u9:0 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-7:2)
RIP: 0010:hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520
Code: c1 8b 89 ee e8 90 b1 8a fe e9 cf fc ff ff e8 b6 63 23 ff 4c 89 ef e8 ae 68 e3 08 48 c7 c7 20 f4 c1 8b 89 ee e8 70 b1 8a 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:ffffc900001eec00 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff888105842000 RCX: 97e605ffaea22b00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc900001ee927 R09: 1ffff9200003dd24
R10: dffffc0000000000 R11: fffff5200003dd25 R12: 0000000000000000
R13: ffff8881058420e0 R14: ffff888024876700 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b840a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555680355c8 CR3: 0000000108f42000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 hfs_bmap_alloc+0x5bb/0x640 fs/hfs/btree.c:326
 hfs_btree_inc_height+0xf6/0xac0 fs/hfs/brec.c:471
 hfs_brec_insert+0x743/0xbd0 fs/hfs/brec.c:148
 __hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
 hfs_ext_write_extent+0x161/0x1e0 fs/hfs/extent.c:144
 hfs_write_inode+0x91/0x7d0 fs/hfs/inode.c:429
 write_inode fs/fs-writeback.c:1564 [inline]
 __writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1784
 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015
 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195
 wb_do_writeback fs/fs-writeback.c:2342 [inline]
 wb_workfn+0x409/0xef0 fs/fs-writeback.c:2382
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
