Re: [PATCH] `pg_dump -Fd` doesn't check write return status...

On Tue, Apr 22, 2014 at 03:19:15PM -0400, Bruce Momjian wrote:
> On Sat, Mar 1, 2014 at 12:27:19PM -0800, Sean Chittenden wrote:
> > The attached patch fixes the case when `pg_dump -Fd …` is called
> > on a partition where write(2) fails for some reason or another. In
> > this case, backup jobs were returning with a successful exit code even
> > though most of the files in the dump directory were all zero length.
> >
> > I haven’t tested this patch’s failure conditions but the fix seems
> > simple enough: cfwrite() needs to have its return status checked
> > everywhere and exit_horribly() upon any failure. In this case,
> > callers of _WriteData() were not checking the return status and were
> > discarding the negative return status (e.g. ENOSPC).
> >
> > I made a cursory pass over the code and found one other instance where
> > write status wasn’t being checked and also included that.
>
> As is often the case with pg_dump, the problems you saw are a small part
> of a larger set of problems in that code --- there is general ignoring of
> read and write errors.
>
> I have developed a comprehensive patch that addresses all the issues I
> could find. The use of function pointers and the calling of functions
> directly and through function pointers makes the fix quite complex. I
> ended up placing checks at the lowest level and removing checks at
> higher layers where they were sporadically placed.
>
> Patch attached. I have tested dump/restore of all four dump output
> formats with the 9.3 regression database and all tests passed. I
> believe this patch is too complex to backpatch, and I don't know how it
> could be fixed more simply.

Patch applied. Thanks for the report.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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