From f9b50b7c18c8ce7de1fee59409fe23c58d438190 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Mon, 19 Aug 2013 17:48:17 -0400 Subject: [PATCH] Fix removal of files in pgstats directories Instead of deleting all files in stats_temp_directory and the permanent directory on a crash, only remove those files that match the pattern of files we actually write in them, to avoid possibly clobbering existing unrelated contents of the temporary directory. Per complaint from Jeff Janes, and subsequent discussion, starting at message CAMkU=1z9+7RsDODnT4=cDFBRBp8wYQbd_qsLcMtKEf-oFwuOdQ@mail.gmail.com Also, fix a bug in the same routine to avoid removing files from the permanent directory twice (instead of once from that directory and then from the temporary directory), also per report from Jeff Janes, in message CAMkU=1wbk947=-pAosDMX5VC+sQw9W4ttq6RM9rXu=MjNeEQKA@mail.gmail.com --- src/backend/postmaster/pgstat.c | 33 ++++++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c index a52377fc9d..c16dd036c0 100644 --- a/src/backend/postmaster/pgstat.c +++ b/src/backend/postmaster/pgstat.c @@ -563,15 +563,37 @@ pgstat_reset_remove_files(const char *directory) struct dirent *entry; char fname[MAXPGPATH]; - dir = AllocateDir(pgstat_stat_directory); - while ((entry = ReadDir(dir, pgstat_stat_directory)) != NULL) + dir = AllocateDir(directory); + while ((entry = ReadDir(dir, directory)) != NULL) { - if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) + int nitems; + Oid tmp_oid; + char tmp_type[8]; + char tmp_rest[2]; + + if (strncmp(entry->d_name, ".", 2) == 0 || + strncmp(entry->d_name, "..", 3) == 0) continue; - /* XXX should we try to ignore files other than the ones we write? */ + /* + * Skip directory entries that don't match the file names we write. + * See get_dbstat_filename for the database-specific pattern. + */ + nitems = sscanf(entry->d_name, "db_%u.%5s%1s", + &tmp_oid, tmp_type, tmp_rest); + if (nitems != 2) + { + nitems = sscanf(entry->d_name, "global.%5s%1s", + tmp_type, tmp_rest); + if (nitems != 1) + continue; + } + + if (strncmp(tmp_type, "tmp", 4) != 0 && + strncmp(tmp_type, "stat", 5) != 0) + continue; - snprintf(fname, MAXPGPATH, "%s/%s", pgstat_stat_directory, + snprintf(fname, MAXPGPATH, "%s/%s", directory, entry->d_name); unlink(fname); } @@ -3631,6 +3653,7 @@ get_dbstat_filename(bool permanent, bool tempname, Oid databaseid, { int printed; + /* NB -- pgstat_reset_remove_files knows about the pattern this uses */ printed = snprintf(filename, len, "%s/db_%u.%s", permanent ? PGSTAT_STAT_PERMANENT_DIRECTORY : pgstat_stat_directory, -- 2.40.0