Re: [patch] Fix checksum verification in base backups for zero page headers - Mailing list pgsql-hackers

From Anastasia Lubennikova
Subject Re: [patch] Fix checksum verification in base backups for zero page headers
Date
Msg-id ce25a60e-bd70-6554-1e8f-7e4dc9f6ce59@postgrespro.ru
Whole thread Raw
In response to Re: [patch] Fix checksum verification in base backups for zero page headers  (Michael Paquier <michael@paquier.xyz>)
Responses Re: [patch] Fix checksum verification in base backups for zero page headers
List pgsql-hackers
On 26.10.2020 04:13, Michael Paquier wrote:
> On Fri, Oct 23, 2020 at 08:00:08AM +0900, Michael Paquier wrote:
>> Yeah, we could try to make the logic a bit more complicated like
>> that.  However, for any code path relying on a page read without any
>> locking insurance, we cannot really have a lot of trust in any of the
>> fields assigned to the page as this could just be random corruption
>> garbage, and the only thing I am ready to trust here a checksum
>> mismatch check, because that's the only field on the page that's
>> linked to its full contents on the 8k page.  This also keeps the code
>> simpler.
> A small update here.  I have extracted the refactored part for
> PageIsVerified() and committed it as that's independently useful.
> This makes the patch proposed here simpler on HEAD, leading to the
> attached.
> --
> Michael

Thank you for committing the first part.

In case you need a second opinion on the remaining patch, it still looks 
good to me.

-- 
Anastasia Lubennikova
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company




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