fix "Success" error messages

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

To: pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2019-06-18T12:35:02Z

Lists: pgsql-hackers

Attachments

0001-Better-error-messages-for-short-reads-writes-in-SLRU.patch (text/plain) patch 0001
0002-Use-consistent-style-for-checking-return-from-system.patch (text/plain) patch 0002

In a case of a corrupted database, I saw an error message like

    Could not read from file ...: Success.

from the SLRU module.  This is because it checks that it reads or writes
exactly BLCKSZ, and else goes to the error path.  The attached patch
gives a different error message in this case.

Because of the structure of this code, we don't have the information to
do the usual "read %d of %zu", but at least this is better than
reporting a "success" error.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Better error messages for short reads/writes in SLRU
- 6ef121647f7f 12.0 landed
- 396e4afdbcbf 13.0 landed
pg_checksums: Handle read and write returns correctly
- 3e20b7fa408f 12.0 landed
- 1d7a6e3eb459 13.0 landed
Use consistent style for checking return from system calls
- 7e9a4c5c3dca 13.0 landed