Re: pgsql: Fix page modification outside of critical section in GIN

Alexander Korotkov <akorotkov@postgresql.org> writes:
> Fix page modification outside of critical section in GIN
> By oversight 52ac6cd2d0 makes ginDeletePage() sets pd_prune_xid of page to be
> deleted before entering the critical section.  It appears that only versions 11
> and later were affected by this oversight.

I happened to notice, while reviewing stuff for the release notes,
that this patch does not do what the commit message says.  The
previous code modified the pd_prune_xid of the "dBuffer" page,
but now it's modifying the pd_prune_xid of the "lBuffer" page.
Is that actually correct?  If it isn't, maybe you need to move
the GinPageSetDeleteXid call down a bit further, next to the
GinPageSetDeleted call (by which time the "page" variable has
been restored to the right thing).

Another idea which would be safer if a bit more invasive is to stop
using the single "page" variable for two purposes.

            regards, tom lane