rbd: ignore failures when reading from default conf location

If we are reading from the default config location, ignore any failures.
It is perfectly legal for the user to specify exactly the options they need
and to not rely on any config file.
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/rbd.c

@@ -298,11 +298,8 @@ static int qemu_rbd_create(const char *filename, QEMUOptionParameter *options)
     }
 
     if (strstr(conf, "conf=") == NULL) {
-        if (rados_conf_read_file(cluster, NULL) < 0) {
-            error_report("error reading config file");
-            rados_shutdown(cluster);
-            return -EIO;
-        }
+        /* try default location, but ignore failure */
+        rados_conf_read_file(cluster, NULL);
     }
 
     if (conf[0] != '\0' &&
@@ -441,11 +438,8 @@ static int qemu_rbd_open(BlockDriverState *bs, const char *filename, int flags)
     }
 
     if (strstr(conf, "conf=") == NULL) {
-        r = rados_conf_read_file(s->cluster, NULL);
-        if (r < 0) {
-            error_report("error reading config file");
-            goto failed_shutdown;
-        }
+        /* try default location, but ignore failure */
+        rados_conf_read_file(s->cluster, NULL);
     }
 
     if (conf[0] != '\0') {