Thank you very much for your review. We refactored our patch with new names and comments.
For ReadBufferExtended hook, yes, Readbuffer with P_NEW will then call smgrextend. But in smgrextend, we cannot get the oid of a relation, and it will take some time to get the oid via smgrrelation. We would like to add a hook just before the smgrextend to get the oid and avoid use RelidByRelfilenode(). New patch is attached in the attachment. Thank a lot! Regards, Haozhou On Wed, Nov 21, 2018 at 10:48 PM Robert Haas <robertmh...@gmail.com> wrote: > On Tue, Nov 20, 2018 at 2:20 AM Haozhou Wang <haw...@pivotal.io> wrote: > > We prepared a patch that includes the hook points. And such hook points > are needed for disk quota extension. > > There are two hooks. > > One is SmgrStat_hook. It's used to perform ad-hoc logic in storage when > doing smgr create/extend/truncate in general. As for disk quota extension, > this hook is used to detect active tables(new created tables, tables > extending new blocks, or tables being truncated) > > The other is BufferExtendCheckPerms_hook. It's used to perform ad-hoc > logic when buffer extend a new block. Since ReadBufferExtended is a hot > function, we call this hook only when blockNum == P_NEW. As for disk quota > extension, this hook is used to do query enforcement during the query is > loading data. > > > > Any comments are appreciated. > > +1 for adding some hooks to support this kind of thing, but I think > the names you've chosen are not very good. The hook name should > describe the place from which it is called, not the purpose for which > one imagines that it will be used, because somebody else might imagine > another use. Both BufferExtendCheckPerms_hook_type and > SmgrStat_hook_type are imagining that they know what the hook does - > CheckPerms in the first case and Stat in the second case. > > For this particular purpose, I don't immediately see why you need a > hook in both places. If ReadBuffer is called with P_NEW, aren't we > guaranteed to end up in smgrextend()? > > -- > Robert Haas > EnterpriseDB: http://www.enterprisedb.com > The Enterprise PostgreSQL Company >
disk_quota_hooks_v2.patch
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