[PATCH 3/4] xfs: log recovery needs to validate against sb_meta_uuid

[Eric Sandeen]

On 8/3/15 9:41 AM, Eric Sandeen wrote:
> On 8/3/15 12:40 AM, Dave Chinner wrote:
>> From: Dave Chinner <dchinner at redhat.com>
>>
>> Now that sb_uuid can be changed by the user, we cannot use this to
>> validate the metadata blocks being recovered belong to this
>> filesystem. We must check against the sb_meta_uuid as that will
>> remain unchanged.
>>
>> There is a complication in this code - the superblock itself. We can
>> not check the sb_meta_uuid unconditionally, as that may not be set
>> on disk. Hence we must verify the superblock sb_uuid matches between
>> the log record and the in-core superblock.
>>
>> Found by inspection after the previous two problems were found.
> 
> So, I also had this in my older patchset, I think it's needed for
> proper log recovery as well.  I'm not sure why I didn't hit the
> xlog_recover_get_buf_lsn problem, though:

Oh god, all this is is a difference in unlikely's upstream.  Kill me now!

-Eric