On 09/21/2016 08:43 AM, Michael Paquier wrote:
>> page_stats / page_items should not be used on the metadata page.
>>
>> As these functions are marked as superuser only it is expected that people
>> provides the correct input, especially since the raw page structure is used
>> as the input.
>
> btree functions use the block number to do some sanity checks. You
> cannot do that here as only bytea functions are available, but you
> could do it in verify_hash_page by looking at the opaque data and look
> at LH_META_PAGE. Then add a boolean argument into verify_hash_page to
> see if the caller expects a meta page or not and just issue an error.
> Actually it would be a good idea to put in those safeguards, even if I
> agree with you that calling those functions is at the risk of the
> user... Could you update the patch in this sense?
>
> I had fun doing the same tests, aka running the items and stats
> functions on a meta page, and the meta function on a non-meta page,
> but at my surprise I did not see a crash, so perhaps I was lucky and
> perhaps that was because of OSX.
>
Attached is v5, which add basic page verification.
Thanks for the feedback !
Best regards,
Jesper
