On Wed, Jun 21, 2017 at 9:42 AM, Amit Langote <langote_amit...@lab.ntt.co.jp> wrote: > On 2017/06/20 20:37, Amit Kapila wrote: >> On Tue, Jun 20, 2017 at 1:50 PM, Amit Langote >> <langote_amit...@lab.ntt.co.jp> wrote: >>> On 2017/06/19 23:31, Tom Lane wrote: >>>> I'd suggest a rule like "if pd_lower is smaller than SizeOfPageHeaderData >>>> then don't trust it, but assume all of the page is valid data". >>> >>> Actually, such a check is already in place in the tool, whose condition >>> looks like: >>> >>> if (PageGetPageSize(header) == BLCKSZ && >>> PageGetPageLayoutVersion(header) == PG_PAGE_LAYOUT_VERSION && >>> (header->pd_flags & ~PD_VALID_FLAG_BITS) == 0 && >>> header->pd_lower >= SizeOfPageHeaderData && >>> header->pd_lower <= header->pd_upper && >>> header->pd_upper <= header->pd_special && >>> header->pd_special <= BLCKSZ && >>> header->pd_special == MAXALIGN(header->pd_special) && ... >>> >>> which even GIN metapage passes, making it an eligible data page and hence >>> for omitting the hole between pd_lower and pd_upper. >>> >> >> Won't checking for GIN_META in header->pd_flags gives you what you want? > > GIN_META flag is not written into pd_flags but GinPageOpaqueData.flags, > which still requires including GIN's private header.
Did you check this patch with wal_consistency_checking? I am getting failures so your patch does not have the masking of GIN pages completely right: FATAL: inconsistent page found, rel 1663/16385/28133, forknum 0, blkno 0 CONTEXT: WAL redo at 0/39379EB8 for Gin/UPDATE_META_PAGE: That's easily reproducible with installcheck and a standby replaying the changes. I did not look at the code in details to see what you may be missing here. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
