tree: make nvme_ctrl_scan_namespace() idempotent

When issuing a rescan the list of namespaces is not cleared, so
just blindly adding new entries might not yield the expected result.
This patch clears out old entries from the controller namespace list
before adding new ones, ensuring that we only ever have one namespace
with a given name in the list of controller namespaces.

Signed-off-by: Hannes Reinecke <[email protected]>

Author: hreinecke

src/nvme/tree.c

@@ -1840,7 +1840,7 @@ nvme_ns_t nvme_scan_namespace(const char *name)
 static int nvme_ctrl_scan_namespace(nvme_root_t r, struct nvme_ctrl *c,
 				    char *name)
 {
-	struct nvme_ns *n;
+	struct nvme_ns *n, *_n, *__n;
 
 	nvme_msg(r, LOG_DEBUG, "scan controller %s namespace %s\n",
 		 c->name, name);
@@ -1854,7 +1854,11 @@ static int nvme_ctrl_scan_namespace(nvme_root_t r, struct nvme_ctrl *c,
 		nvme_msg(r, LOG_DEBUG, "failed to scan namespace %s\n", name);
 		return -1;
 	}
-
+	nvme_ctrl_for_each_ns_safe(c, _n, __n) {
+		if (strcmp(n->name, _n->name))
+			continue;
+		__nvme_free_ns(_n);
+	}
 	n->s = c->s;
 	n->c = c;
 	list_add(&c->namespaces, &n->entry);