pgsql: Ensure that creation of an empty relfile is fsync'd at checkpoin - Mailing list pgsql-committers

From Heikki Linnakangas
Subject pgsql: Ensure that creation of an empty relfile is fsync'd at checkpoin
Date
Msg-id E1qGi03-001tAU-F3@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Ensure that creation of an empty relfile is fsync'd at checkpoint.

If you create a table and don't insert any data into it, the relation file
is never fsync'd. You don't lose data, because an empty table doesn't have
any data to begin with, but if you crash and lose the file, subsequent
operations on the table will fail with "could not open file" error.

To fix, register an fsync request in mdcreate(), like we do for mdwrite().

Per discussion, we probably should also fsync the containing directory
after creating a new file. But that's a separate and much wider issue.

Backpatch to all supported versions.

Reviewed-by: Andres Freund, Thomas Munro
Discussion: https://www.postgresql.org/message-id/d47d8122-415e-425c-d0a2-e0160829702d%40iki.fi

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/4b4798e1384ce12e19a558708e66c829276cf8d7

Modified Files
--------------
src/backend/storage/smgr/md.c | 3 +++
1 file changed, 3 insertions(+)


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