Fix handling of pg_stat_statements.stat temporary file

Write the file to a temporary name and then rename() it into the
permanent name, to ensure it can't end up half-written and corrupt
in case of a crash during shutdown.

Unlink the file after it has been read so it's removed from the data
directory and not included in base backups going to replication slaves.
This commit is contained in:
Magnus Hagander 2012-05-27 10:54:31 +02:00
parent 532fe28dad
commit 2b97db61dd

View File

@ -511,6 +511,13 @@ pgss_shmem_startup(void)
pfree(buffer);
FreeFile(file);
/*
* Remove the file so it's not included in backups/replication
* slaves, etc. A new file will be written on next shutdown.
*/
unlink(PGSS_DUMP_FILE);
return;
error:
@ -552,7 +559,7 @@ pgss_shmem_shutdown(int code, Datum arg)
if (!pgss_save)
return;
file = AllocateFile(PGSS_DUMP_FILE, PG_BINARY_W);
file = AllocateFile(PGSS_DUMP_FILE ".tmp", PG_BINARY_W);
if (file == NULL)
goto error;
@ -578,16 +585,25 @@ pgss_shmem_shutdown(int code, Datum arg)
goto error;
}
/*
* Rename file into place, so we atomically replace the old one.
*/
if (rename(PGSS_DUMP_FILE ".tmp", PGSS_DUMP_FILE) != 0)
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not rename pg_stat_statement file \"%s\": %m",
PGSS_DUMP_FILE ".tmp")));
return;
error:
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not write pg_stat_statement file \"%s\": %m",
PGSS_DUMP_FILE)));
PGSS_DUMP_FILE ".tmp")));
if (file)
FreeFile(file);
unlink(PGSS_DUMP_FILE);
unlink(PGSS_DUMP_FILE ".tmp");
}
/*