Remove unportable code of IsDir

Michael Paquier · Michael Paquier · commit b84334b8f340 · 2016-01-19T20:51:38.000+09:00
IsDir was somewhat optimized on systems where DT_DIR (dirent.d_type
being not part of the POSIX spec) is present on some systems leading
to more complex logic depending on the file system used, particularly
on XFS this routine was actually broken. Having a call to stat()
should not be that expensive to check if a path is a directory or
not and this is proving to be far more stable coding, so just rely
on that, that's more portable anyway and will avoid future surprises.

Report by Yury Zhuravlev, though I did not use his patch.
diff --git a/catalog.c b/catalog.c
@@ -90,24 +90,14 @@ catalog_get_backup(time_t timestamp)
 }
 
 static bool
-IsDir(const char *dirpath, const DIR *dir, const struct dirent *ent)
+IsDir(const char *dirpath, const char *entry)
 {
-#if defined(DT_DIR)
-	return ent->d_type == DT_DIR;
-#elif defined(_finddata_t)
-	/* Optimization for VC++ on Windows. */
-	return (dir->dd_dta.attrib & FILE_ATTRIBUTE_DIRECTORY) != 0;
-#else
-	/* Portable implementation because dirent.d_type is not in POSIX. */
 	char		path[MAXPGPATH];
 	struct stat	st;
 
-	strlcpy(path, dirpath, MAXPGPATH);
-	strlcat(path, "/", MAXPGPATH);
-	strlcat(path, ent->d_name, MAXPGPATH);
+	snprintf(path, MAXPGPATH, "%s/%s", dirpath, entry);
 
 	return stat(path, &st) == 0 && S_ISDIR(st.st_mode);
-#endif
 }
 
 /*
@@ -157,7 +147,7 @@ catalog_get_backup_list(const pgBackupRange *range)
 	for (; (date_ent = readdir(date_dir)) != NULL; errno = 0)
 	{
 		/* skip not-directory entries and hidden entries */
-		if (!IsDir(backup_path, date_dir, date_ent) || date_ent->d_name[0] == '.')
+		if (!IsDir(backup_path, date_ent->d_name) || date_ent->d_name[0] == '.')
 			continue;
 
 		/* skip online WAL backup directory */
@@ -183,20 +173,21 @@ catalog_get_backup_list(const pgBackupRange *range)
 		{
 			char ini_path[MAXPGPATH];
 
-			/* skip not-directory and hidden directories */
-			if (!IsDir(date_path, date_dir, time_ent) || time_ent->d_name[0] == '.')
+			/* skip entries that are directories and hidden directories */
+			if (!IsDir(date_path, time_ent->d_name) || time_ent->d_name[0] == '.')
 				continue;
 
 			/* If the time is out of range, skip it. */
 			if (pgBackupRangeIsValid(range) &&
-					(strcmp(begin_time, time_ent->d_name) > 0 ||
-									strcmp(end_time, time_ent->d_name) < 0))
+				(strcmp(begin_time, time_ent->d_name) > 0 ||
+				 strcmp(end_time, time_ent->d_name) < 0))
 				continue;
 
 			/* read backup information from backup.ini */
 			snprintf(ini_path, MAXPGPATH, "%s/%s/%s", date_path,
-				time_ent->d_name, BACKUP_INI_FILE);
+					 time_ent->d_name, BACKUP_INI_FILE);
 			backup = catalog_read_ini(ini_path);
+
 			/* ignore corrupted backup */
 			if (backup)
 			{
