Re: Use pg_pwritev_with_retry() instead of write() in dir_open_for_write() to avoid partial writes?

On Thu, Oct 27, 2022 at 11:24 AM Michael Paquier <michael(at)paquier(dot)xyz> wrote:
>
> On Thu, Sep 29, 2022 at 08:09:56PM -0700, Nathan Bossart wrote:
> > Looks reasonable to me.
>
> 0001, to move pg_pwritev_with_retry() to a new home, seems fine, so
> applied.

Thanks.

> Regarding 0002, using pg_pwrite_zeros() as a routine name, as
> suggested by Thomas, sounds good to me.

Changed.

> However, I am not really a
> fan of its dependency with PGAlignedXLogBlock, because it should be
> able to work with any buffers of any sizes, as long as the input
> buffer is aligned, shouldn't it? For example, what about
> PGAlignedBlock? So, should we make this more extensible? My guess
> would be the addition of the block size and the block pointer to the
> arguments of pg_pwrite_zeros(), in combination with a check to make
> sure that the input buffer is MAXALIGN()'d (with an Assert() rather
> than just an elog/pg_log_error?).

+1 to pass in the aligned buffer, its size and an assertion on the buffer size.

Please see the attached v7 patch.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com