Horton

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

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Nathan Bossart <nathandbossart@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-11-08T04:07:57Z
Lists: pgsql-hackers 
On Tue, Nov 01, 2022 at 08:32:48AM +0530, Bharath Rupireddy wrote:
> I'm attaching the v9 patch from upthread here again for further review
> and to make CF bot happy.

So, I have looked at that, and at the end concluded that Andres'
suggestion to use PGAlignedBlock in pg_write_zeros() will serve better
in the long run.  Thomas has mentioned upthread that some of the
comments don't need to be that long, so I have tweaked these to be
minimal, and updated a few more areas.  Note that this has been split
into two commits: one to introduce the new routine in file_utils.c and
a second for the switch in walmethods.c.
--
Michael

Commits

  1. Revise pg_pwrite_zeros()

  2. Use pg_pwrite_zeros() in walmethods.c

  3. Introduce pg_pwrite_zeros() in fileutils.c

  4. Move pg_pwritev_with_retry() to src/common/file_utils.c

  5. Restore pg_pread and friends.

  6. Remove dead pread and pwrite replacement code.