Horton

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

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

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From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: andres@anarazel.de
Cc: bharath.rupireddyforpostgres@gmail.com, michael@paquier.xyz, alvherre@alvh.no-ip.org, nathandbossart@gmail.com, thomas.munro@gmail.com, pgsql-hackers@lists.postgresql.org
Date: 2023-02-15T01:28:37Z
Lists: pgsql-hackers 
At Tue, 14 Feb 2023 16:55:25 -0800, Andres Freund <andres@anarazel.de> wrote in 
> Hi,
> 
> On 2023-02-14 18:00:00 +0530, Bharath Rupireddy wrote:
> > Done, PSA v2 patch.
> 
> This feels way too complicated to me.  How about something more like the
> attached?

I like this one, but the parameters offset and size are in a different
order from pwrite(fd, buf, count, offset).  I perfer the arrangement
suggested by Bharath. And isn't it better to use Min(remaining_size,
BLCKSZ) instead of a bare if statement?

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

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.