devlink: convert linecards dump to devlink_nl_instance_iter_dump()

Benefit from recently introduced instance iteration and convert
linecards .dumpit generic netlink callback to use it.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/devlink/devl_internal.h

@@ -167,6 +167,7 @@ extern const struct devlink_gen_cmd devl_gen_info;
 extern const struct devlink_gen_cmd devl_gen_trap;
 extern const struct devlink_gen_cmd devl_gen_trap_group;
 extern const struct devlink_gen_cmd devl_gen_trap_policer;
+extern const struct devlink_gen_cmd devl_gen_linecard;
 
 /* Ports */
 int devlink_port_netdevice_event(struct notifier_block *nb,

net/devlink/leftover.c

@@ -2105,20 +2105,14 @@ static int devlink_nl_cmd_linecard_get_doit(struct sk_buff *skb,
 	return genlmsg_reply(msg, info);
 }
 
-static int devlink_nl_cmd_linecard_get_dumpit(struct sk_buff *msg,
+static int devlink_nl_cmd_linecard_get_dump_one(struct sk_buff *msg,
+						struct devlink *devlink,
 						struct netlink_callback *cb)
 {
 	struct devlink_nl_dump_state *state = devlink_dump_state(cb);
 	struct devlink_linecard *linecard;
-	struct devlink *devlink;
-	int err;
-
-	devlink_dump_for_each_instance_get(msg, state, devlink) {
 	int idx = 0;
-
-		devl_lock(devlink);
-		if (!devl_is_registered(devlink))
-			goto next_devlink;
+	int err = 0;
 
 	list_for_each_entry(linecard, &devlink->linecard_list, list) {
 		if (idx < state->idx) {
@@ -2134,21 +2128,19 @@ static int devlink_nl_cmd_linecard_get_dumpit(struct sk_buff *msg,
 					       cb->extack);
 		mutex_unlock(&linecard->state_lock);
 		if (err) {
-				devl_unlock(devlink);
-				devlink_put(devlink);
 			state->idx = idx;
-				goto out;
+			break;
 		}
 		idx++;
 	}
-next_devlink:
-		devl_unlock(devlink);
-		devlink_put(devlink);
-	}
-out:
-	return msg->len;
+
+	return err;
 }
 
+const struct devlink_gen_cmd devl_gen_linecard = {
+	.dump_one		= devlink_nl_cmd_linecard_get_dump_one,
+};
+
 static struct devlink_linecard_type *
 devlink_linecard_type_lookup(struct devlink_linecard *linecard,
 			     const char *type)
@@ -9010,7 +9002,7 @@ const struct genl_small_ops devlink_nl_ops[56] = {
 	{
 		.cmd = DEVLINK_CMD_LINECARD_GET,
 		.doit = devlink_nl_cmd_linecard_get_doit,
-		.dumpit = devlink_nl_cmd_linecard_get_dumpit,
+		.dumpit = devlink_nl_instance_iter_dump,
 		.internal_flags = DEVLINK_NL_FLAG_NEED_LINECARD,
 		/* can be retrieved by unprivileged users */
 	},

net/devlink/netlink.c

@@ -191,6 +191,7 @@ static const struct devlink_gen_cmd *devl_gen_cmds[] = {
 	[DEVLINK_CMD_TRAP_GET]		= &devl_gen_trap,
 	[DEVLINK_CMD_TRAP_GROUP_GET]	= &devl_gen_trap_group,
 	[DEVLINK_CMD_TRAP_POLICER_GET]	= &devl_gen_trap_policer,
+	[DEVLINK_CMD_LINECARD_GET]	= &devl_gen_linecard,
 	[DEVLINK_CMD_SELFTESTS_GET]	= &devl_gen_selftests,
 };