From 8232d6df4c943a30c08e65d7ea893cb762bc5612 Mon Sep 17 00:00:00 2001 From: Magnus Hagander Date: Wed, 28 May 2014 12:40:45 +0200 Subject: [PATCH] Ensure cleanup in case of early errors in streaming base backups Move the code that sends the initial status information as well as the calculation of paths inside the ENSURE_ERROR_CLEANUP block. If this code failed, we would "leak" a counter of number of concurrent backups, thereby making the system always believe it was in backup mode. This could happen if the sending failed (which it probably never did given that the small amount of data to send would never cause a flush) or if the psprintf calls ran out of memory. Both are very low risk, but all operations after do_pg_start_backup should be protected. --- src/backend/replication/basebackup.c | 29 +++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c index a3bf5001ec..b387612c09 100644 --- a/src/backend/replication/basebackup.c +++ b/src/backend/replication/basebackup.c @@ -134,19 +134,12 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir) startptr = do_pg_start_backup(opt->label, opt->fastcheckpoint, &starttli, &labelfile); - SendXlogRecPtrResult(startptr, starttli); - /* - * Calculate the relative path of temporary statistics directory in order - * to skip the files which are located in that directory later. + * Once do_pg_start_backup has been called, ensure that any failure causes + * us to abort the backup so we don't "leak" a backup counter. For this reason, + * *all* functionality between do_pg_start_backup() and do_pg_stop_backup() + * should be inside the error cleanup block! */ - if (is_absolute_path(pgstat_stat_directory) && - strncmp(pgstat_stat_directory, DataDir, datadirpathlen) == 0) - statrelpath = psprintf("./%s", pgstat_stat_directory + datadirpathlen + 1); - else if (strncmp(pgstat_stat_directory, "./", 2) != 0) - statrelpath = psprintf("./%s", pgstat_stat_directory); - else - statrelpath = pgstat_stat_directory; PG_ENSURE_ERROR_CLEANUP(base_backup_cleanup, (Datum) 0); { @@ -155,6 +148,20 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir) struct dirent *de; tablespaceinfo *ti; + SendXlogRecPtrResult(startptr, starttli); + + /* + * Calculate the relative path of temporary statistics directory in order + * to skip the files which are located in that directory later. + */ + if (is_absolute_path(pgstat_stat_directory) && + strncmp(pgstat_stat_directory, DataDir, datadirpathlen) == 0) + statrelpath = psprintf("./%s", pgstat_stat_directory + datadirpathlen + 1); + else if (strncmp(pgstat_stat_directory, "./", 2) != 0) + statrelpath = psprintf("./%s", pgstat_stat_directory); + else + statrelpath = pgstat_stat_directory; + /* Collect information about all tablespaces */ while ((de = ReadDir(tblspcdir, "pg_tblspc")) != NULL) {