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

On Fri, Aug 05, 2022 at 03:55:26PM +0530, Bharath Rupireddy wrote:
> I noticed that dir_open_for_write() in walmethods.c uses write() for
> WAL file initialization (note that this code is used by pg_receivewal
> and pg_basebackup) as opposed to core using pg_pwritev_with_retry() in
> XLogFileInitInternal() to avoid partial writes. Do we need to fix
> this?

0d56acfb has moved pg_pwritev_with_retry to be backend-only in fd.c :/

> Thoughts?

Makes sense to me for the WAL segment pre-padding initialization, as
we still want to point to the beginning of the segment after we are
done with the pre-padding, and the code has an extra lseek().
--
Michael