Re: [PATCH 3/6] xfs_repair: enforce that inode btree chunks can't point to AG headers

Eric Sandeen
2019-12-12T19:11:19Z

On 12/5/19 10:28 AM, Darrick J. Wong wrote:
> On Thu, Dec 05, 2019 at 09:37:27AM -0500, Brian Foster wrote:
>> On Wed, Dec 04, 2019 at 09:04:43AM -0800, Darrick J. Wong wrote:
>>> From: Darrick J. Wong <darrick.wong@oracle.com>
>>>
>>> xfs_repair has a very old check that evidently excuses the AG 0 inode
>>> btrees pointing to blocks that are already marked XR_E_INUSE_FS* (e.g.
>>> AG headers). mkfs never formats filesystems that way and it looks like
>>> an error, so purge the check. After this, we always complain if inodes
>>> overlap with AG headers because that should never happen.
>>>
>>> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
>>> ---
>>
>> Strange.. This seems reasonable to me, but any idea on how this might
>> have been used in the past?
>
> I don't have a clue -- this code has been there since the start of the
> xfsprogs git repo and I don't have the pre-git history. Dave said
> "hysterical raisins".

Going back to 2001, I still don't know. It was in the original import.

-Eric