On Thu, Apr 22, 2021 at 11:36 AM Dilip Kumar <dilipbal...@gmail.com> wrote: > > On Thu, Apr 22, 2021 at 10:40 AM Bharath Rupireddy > <bharath.rupireddyforpostg...@gmail.com> wrote: > > > > Hi, > > > > In the PageGetItemIdCareful() introduced by commit a9ce839a, it seems > > like we are using btree page pd_special structure BTPageOpaqueData for > > error case without max aligning it. > > if (ItemIdGetOffset(itemid) + ItemIdGetLength(itemid) > > > BLCKSZ - sizeof(BTPageOpaqueData)) > > ereport(ERROR, > > > > I'm not sure if it is intentional. ISTM that this was actually not a > > problem because the BTPageOpaqueData already has all-aligned(???) > > members (3 uint32, 2 uint16). But it might be a problem if we add > > unaligned bytes. PageInit always max aligns this structure, when we > > initialize the btree page in _bt_pageini and in all other places we > > max align it before use. Since this is an error throwing path, I think > > we should max align it just to be on the safer side. While on it, I > > think we can also replace BLCKSZ with PageGetPageSize(page). > > > > Attaching a small patch. Thoughts? > > +1 for changing to MAXALIGN(sizeof(BTPageOpaqueData)).
Thanks for taking a look at it. I added a CF entry https://commitfest.postgresql.org/33/3089/ so that we don't lose track of it. With Regards, Bharath Rupireddy. EnterpriseDB: http://www.enterprisedb.com
