devlink: load port-ifname map on demand

So far, the port-ifname map was loaded during devlink init
no matter if actually needed or not. Port dump cmd which is utilized
for this in kernel takes lock for every devlink instance.
That may lead to unnecessary blockage of command.

Load the map only in time it is needed to lookup ifname.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/devlink/devlink.c b/devlink/devlink.c
index b69c89778804ee1e3e11a693630c794dfe82242b..b2439aef4d10f1cbf406e1f4d3ae09e12df49d24 100644 (file)
--- a/devlink/devlink.c
+++ b/devlink/devlink.c
@@ -374,6 +374,7 @@ struct dl {
        bool verbose;
        bool stats;
        bool hex;
+       bool map_loaded;
        struct {
                bool present;
                char *bus_name;
@@ -817,13 +818,15 @@ static void ifname_map_fini(struct dl *dl)
        }
 }
 
-static int ifname_map_init(struct dl *dl)
+static void ifname_map_init(struct dl *dl)
 {
-       struct nlmsghdr *nlh;
-       int err;
-
        INIT_LIST_HEAD(&dl->ifname_map_list);
+}
 
+static int ifname_map_load(struct dl *dl)
+{
+       struct nlmsghdr *nlh;
+       int err;
 
        nlh = mnlu_gen_socket_cmd_prepare(&dl->nlg, DEVLINK_CMD_PORT_GET,
                               NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
@@ -841,7 +844,16 @@ static int ifname_map_lookup(struct dl *dl, const char *ifname,
                             uint32_t *p_port_index)
 {
        struct ifname_map *ifname_map;
+       int err;
 
+       if (!dl->map_loaded) {
+               err = ifname_map_load(dl);
+               if (err) {
+                       pr_err("Failed to create index map\n");
+                       return err;
+               }
+               dl->map_loaded = true;
+       }
        list_for_each_entry(ifname_map, &dl->ifname_map_list, list) {
                if (strcmp(ifname, ifname_map->ifname) == 0) {
                        *p_bus_name = ifname_map->bus_name;
@@ -9622,17 +9634,10 @@ static int dl_init(struct dl *dl)
                return -errno;
        }
 
-       err = ifname_map_init(dl);
-       if (err) {
-               pr_err("Failed to create index map\n");
-               goto err_ifname_map_create;
-       }
+       ifname_map_init(dl);
+
        new_json_obj_plain(dl->json_output);
        return 0;
-
-err_ifname_map_create:
-       mnlu_gen_socket_close(&dl->nlg);
-       return err;
 }
 
 static void dl_fini(struct dl *dl)