[PATCH iproute2-next 2/7] devlink: Move dpipe tables query to resources show callback

[Tariq Toukan <tariqt@nvidia.com>]

From: Ido Schimmel <idosch@nvidia.com>

As previously explained, as part of showing device resources, devlink
queries the device's dpipe tables so that it will be able to show the
association between resources and dpipe tables.

Currently, the dpipe tables are queried before the device resources.
This will become a problem when devlink is extended to support dumping
the resources of all available devices.

Therefore, in preparation for resource dump support, move the querying
of the device's dpipe tables to the resources show callback which is
invoked per-device.

There is no difference in the output of the resource show command, but
one functional difference is that errors in dpipe tables query are not
considered fatal. This seems reasonable given that errors are unlikely
and that displaying the dpipe tables is secondary to showing the device
resources.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 devlink/devlink.c | 82 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 62 insertions(+), 20 deletions(-)

diff --git a/devlink/devlink.c b/devlink/devlink.c
index d998520cfd88..7a8be3ad9b6a 100644
--- a/devlink/devlink.c
+++ b/devlink/devlink.c
@@ -8818,6 +8818,9 @@ static void resource_dpipe_tables_show(const struct resource *resource,
 	struct dl *dl = ctx->dl;
 	bool array = false;
 
+	if (!ctx->tables)
+		return;
+
 	list_for_each_entry(table, &ctx->tables->table_list, list)
 		if (table->resource_id == resource->id &&
 		    table->resource_valid)
@@ -8888,17 +8891,75 @@ static void resource_show(struct resource *resource,
 	pr_out_array_end(dl);
 }
 
+static void resources_dpipe_tables_init(struct dpipe_ctx *dpipe_ctx,
+					struct resource_ctx *resource_ctx,
+					struct nlattr **tb)
+{
+	const char *bus_name = mnl_attr_get_str(tb[DEVLINK_ATTR_BUS_NAME]);
+	const char *dev_name = mnl_attr_get_str(tb[DEVLINK_ATTR_DEV_NAME]);
+	struct mnlu_gen_socket nlg_dpipe;
+	struct dl *dl = resource_ctx->dl;
+	struct nlmsghdr *nlh;
+	int err;
+
+	err = dpipe_ctx_init(dpipe_ctx, dl);
+	if (err)
+		return;
+
+	err = mnlu_gen_socket_open(&nlg_dpipe, DEVLINK_GENL_NAME,
+				   DEVLINK_GENL_VERSION);
+	if (err)
+		goto ctx_fini;
+
+	nlh = mnlu_gen_socket_cmd_prepare(&nlg_dpipe,
+					  DEVLINK_CMD_DPIPE_TABLE_GET,
+					  NLM_F_REQUEST);
+
+	mnl_attr_put_strz(nlh, DEVLINK_ATTR_BUS_NAME, bus_name);
+	mnl_attr_put_strz(nlh, DEVLINK_ATTR_DEV_NAME, dev_name);
+
+	err = mnlu_gen_socket_sndrcv(&nlg_dpipe, nlh, cmd_dpipe_table_show_cb,
+				     dpipe_ctx);
+	if (err)
+		goto socket_close;
+
+	resource_ctx->tables = dpipe_ctx->tables;
+	mnlu_gen_socket_close(&nlg_dpipe);
+
+	return;
+
+socket_close:
+	mnlu_gen_socket_close(&nlg_dpipe);
+ctx_fini:
+	dpipe_ctx_fini(dpipe_ctx);
+}
+
+static void resources_dpipe_tables_fini(struct dpipe_ctx *dpipe_ctx,
+					struct resource_ctx *resource_ctx)
+{
+	if (!resource_ctx->tables)
+		return;
+
+	resource_ctx->tables = NULL;
+	dpipe_ctx_fini(dpipe_ctx);
+}
+
 static void
 resources_show(struct resource_ctx *ctx, struct nlattr **tb)
 {
 	struct resources *resources = ctx->resources;
+	struct dpipe_ctx dpipe_ctx = {};
 	struct resource *resource;
 
+	resources_dpipe_tables_init(&dpipe_ctx, ctx, tb);
+
 	list_for_each_entry(resource, &resources->resource_list, list) {
 		pr_out_handle_start_arr(ctx->dl, tb);
 		resource_show(resource, ctx);
 		pr_out_handle_end(ctx->dl);
 	}
+
+	resources_dpipe_tables_fini(&dpipe_ctx, ctx);
 }
 
 static int resources_get(struct resource_ctx *ctx, struct nlattr **tb)
@@ -8933,7 +8994,6 @@ static int cmd_resource_dump_cb(const struct nlmsghdr *nlh, void *data)
 static int cmd_resource_show(struct dl *dl)
 {
 	struct nlmsghdr *nlh;
-	struct dpipe_ctx dpipe_ctx = {};
 	struct resource_ctx resource_ctx = {};
 	int err;
 
@@ -8941,27 +9001,11 @@ static int cmd_resource_show(struct dl *dl)
 	if (err)
 		return err;
 
-	nlh = mnlu_gen_socket_cmd_prepare(&dl->nlg, DEVLINK_CMD_DPIPE_TABLE_GET,
-			       NLM_F_REQUEST);
-	dl_opts_put(nlh, dl);
-
-	err = dpipe_ctx_init(&dpipe_ctx, dl);
-	if (err)
-		return err;
-
-	err = mnlu_gen_socket_sndrcv(&dl->nlg, nlh, cmd_dpipe_table_show_cb,
-				  &dpipe_ctx);
-	if (err) {
-		pr_err("error get tables %s\n", strerror(dpipe_ctx.err));
-		goto out;
-	}
-
 	err = resource_ctx_init(&resource_ctx, dl);
 	if (err)
-		goto out;
+		return err;
 
 	resource_ctx.print_resources = true;
-	resource_ctx.tables = dpipe_ctx.tables;
 	nlh = mnlu_gen_socket_cmd_prepare(&dl->nlg, DEVLINK_CMD_RESOURCE_DUMP,
 			       NLM_F_REQUEST | NLM_F_ACK);
 	dl_opts_put(nlh, dl);
@@ -8970,8 +9014,6 @@ static int cmd_resource_show(struct dl *dl)
 				  &resource_ctx);
 	pr_out_section_end(dl);
 	resource_ctx_fini(&resource_ctx);
-out:
-	dpipe_ctx_fini(&dpipe_ctx);
 	return err;
 }
 
-- 
2.44.0