Emit a warning message when no controller-id is specified

diff --git a/nvme.c b/nvme.c
index e2e2abf15b67c661f531cb29a90e173df7fdde72..df803ef1c61b275aa6456f0d9949bdee66fe3363 100644 (file)
--- a/nvme.c
+++ b/nvme.c
@@ -1058,7 +1058,7 @@ static int nvme_attach_ns(int argc, char **argv, int attach, const char *desc, s
        __u16 ctrlist[2048];
 
        const char *namespace_id = "namespace to attach";
-       const char *cont = "comma-sep controller id list";
+       const char *cont = "optional comma-sep controller id list";
 
        struct config {
                char  *cntlist;
@@ -1088,7 +1088,11 @@ static int nvme_attach_ns(int argc, char **argv, int attach, const char *desc, s
        }
 
        num = argconfig_parse_comma_sep_array(cfg.cntlist, list, 2047);
-       if (num < 1) {
+       if (!num) {
+               fprintf(stderr, "warning: empty controller-id list will result in no actual change in namespace attachment\n");
+       }
+
+       if (num == -1) {
                fprintf(stderr, "%s: controller id list is required\n",
                                                cmd->name);
                err = -EINVAL;