kdbus: simplify collecting metadata on messages

Instead of collecting metadata on the call-side for each message origin,
move it to the core: Handle it directly before allocating the message
slice.

The number of times we call into the helper stays exactly the same, but
the code paths are reduced significantly.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

4 files changed, 16 insertions, 39 deletions

diff --git a/ipc/kdbus/bus.c b/ipc/kdbus/bus.c
index 16f69acfec8a..bc3c3c0383cb 100644
--- a/ipc/kdbus/bus.c
+++ b/ipc/kdbus/bus.c
@@ -284,13 +284,6 @@ void kdbus_bus_broadcast(struct kdbus_bus *bus,
 			 */
 			if (!kdbus_conn_policy_talk(conn_dst, NULL, conn_src))
 				continue;
-
-			ret = kdbus_kmsg_collect_metadata(kmsg, conn_src,
-							  conn_dst);
-			if (ret < 0) {
-				kdbus_conn_lost_message(conn_dst);
-				continue;
-			}
 		} else {
 			/*
 			 * Check if there is a policy db that prevents the
@@ -338,15 +331,6 @@ void kdbus_bus_eavesdrop(struct kdbus_bus *bus,
 
 	down_read(&bus->conn_rwlock);
 	list_for_each_entry(conn_dst, &bus->monitors_list, monitor_entry) {
-		if (conn_src) {
-			ret = kdbus_kmsg_collect_metadata(kmsg, conn_src,
-							  conn_dst);
-			if (ret < 0) {
-				kdbus_conn_lost_message(conn_dst);
-				continue;
-			}
-		}
-
 		ret = kdbus_conn_entry_insert(conn_src, conn_dst, kmsg, NULL,
 					      NULL);
 		if (ret < 0)
diff --git a/ipc/kdbus/connection.c b/ipc/kdbus/connection.c
index 2ce63ccca3b4..25e49455b24b 100644
--- a/ipc/kdbus/connection.c
+++ b/ipc/kdbus/connection.c
@@ -813,7 +813,12 @@ static int kdbus_conn_entry_sync_attach(struct kdbus_conn *conn_dst,
 {
 	struct kdbus_queue_entry *entry;
 	int remote_ret;
-	int ret = 0;
+	int ret;
+
+	ret = kdbus_kmsg_collect_metadata(kmsg, reply_wake->reply_src,
+					  conn_dst);
+	if (ret < 0)
+		return ret;
 
 	mutex_lock(&reply_wake->reply_dst->lock);
 
@@ -879,6 +884,12 @@ int kdbus_conn_entry_insert(struct kdbus_conn *conn_src,
 	struct kdbus_queue_entry *entry;
 	int ret;
 
+	if (conn_src) {
+		ret = kdbus_kmsg_collect_metadata(kmsg, conn_src, conn_dst);
+		if (ret < 0)
+			return ret;
+	}
+
 	kdbus_conn_lock2(conn_src, conn_dst);
 
 	entry = kdbus_conn_entry_make(conn_src, conn_dst, kmsg);
@@ -1132,12 +1143,6 @@ static int kdbus_conn_reply(struct kdbus_conn *src, struct kdbus_kmsg *kmsg)
 		goto exit;
 	}
 
-	/* attach metadata */
-
-	ret = kdbus_kmsg_collect_metadata(kmsg, src, dst);
-	if (ret < 0)
-		goto exit;
-
 	/* send message */
 
 	kdbus_bus_eavesdrop(bus, src, kmsg);
@@ -1210,12 +1215,6 @@ static struct kdbus_reply *kdbus_conn_call(struct kdbus_conn *src,
 		goto exit;
 	}
 
-	/* attach metadata */
-
-	ret = kdbus_kmsg_collect_metadata(kmsg, src, dst);
-	if (ret < 0)
-		goto exit;
-
 	/* send message */
 
 	kdbus_bus_eavesdrop(bus, src, kmsg);
@@ -1279,12 +1278,6 @@ static int kdbus_conn_unicast(struct kdbus_conn *src, struct kdbus_kmsg *kmsg)
 		}
 	}
 
-	/* attach metadata */
-
-	ret = kdbus_kmsg_collect_metadata(kmsg, src, dst);
-	if (ret < 0)
-		goto exit;
-
 	/* send message */
 
 	if (!is_signal)
diff --git a/ipc/kdbus/message.c b/ipc/kdbus/message.c
index 974e8c4f6039..9346a04e10ef 100644
--- a/ipc/kdbus/message.c
+++ b/ipc/kdbus/message.c
@@ -619,8 +619,8 @@ exit_free:
  *
  * Return: 0 on success, negative error code on failure.
  */
-int kdbus_kmsg_collect_metadata(struct kdbus_kmsg *kmsg, struct kdbus_conn *src,
-				struct kdbus_conn *dst)
+int kdbus_kmsg_collect_metadata(const struct kdbus_kmsg *kmsg,
+				struct kdbus_conn *src, struct kdbus_conn *dst)
 {
 	u64 attach;
 	int ret;
diff --git a/ipc/kdbus/message.h b/ipc/kdbus/message.h
index 88e2366e49b6..9a11389d9f27 100644
--- a/ipc/kdbus/message.h
+++ b/ipc/kdbus/message.h
@@ -125,7 +125,7 @@ struct kdbus_kmsg *kdbus_kmsg_new(struct kdbus_bus *bus, size_t extra_size);
 struct kdbus_kmsg *kdbus_kmsg_new_from_cmd(struct kdbus_conn *conn,
 					   struct kdbus_cmd_send *cmd_send);
 void kdbus_kmsg_free(struct kdbus_kmsg *kmsg);
-int kdbus_kmsg_collect_metadata(struct kdbus_kmsg *kmsg, struct kdbus_conn *src,
-				struct kdbus_conn *dst);
+int kdbus_kmsg_collect_metadata(const struct kdbus_kmsg *kmsg,
+				struct kdbus_conn *src, struct kdbus_conn *dst);
 
 #endif