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: kworker/u8:13/2888
Modules linked in:
CPU: 0 UID: 0 PID: 2888 Comm: kworker/u8:13 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Workqueue: writeback wb_workfn (flush-7:7)
RIP: 0010:hfs_bnode_create+0x45a/0x4e0 fs/hfs/bnode.c:478
Code: a9 8b 89 ee e8 07 2e 6d fe e9 d6 fc ff ff e8 4d a0 0d ff 4c 89 ef e8 25 af bd 08 48 c7 c7 e0 fb a9 8b 89 ee e8 e7 2d 6d 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:ffffc9000e8eece8 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff888031b6a000 RCX: 1bf08900c3144200
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52001d1dd4d R12: 0000000000000000
R13: ffff888031b6a0d0 R14: ffff888026d30e00 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88812470f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8823931000 CR3: 0000000039cb0000 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_write_extent+0x17d/0x210 fs/hfs/extent.c:150
 hfs_write_inode+0x117/0xa00 fs/hfs/inode.c:475
 write_inode fs/fs-writeback.c:1629 [inline]
 __writeback_single_inode+0x6a0/0x1230 fs/fs-writeback.c:1872
 writeback_sb_inodes+0x9db/0x1aa0 fs/fs-writeback.c:2120
 wb_writeback+0x41c/0xad0 fs/fs-writeback.c:2305
 wb_do_writeback fs/fs-writeback.c:2473 [inline]
 wb_workfn+0x437/0x10f0 fs/fs-writeback.c:2518
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>