tipc: Optimize detection of duplicate media registration

Streamlines the detection of an attempt to register a TIPC media structure
using an already registered name or type identifier. The revised logic now
reuses an existing routine to detect an existing name and no longer
unnecessarily manipulates the media type counter during an unsuccessful
registration attempt.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

net/tipc/bearer.c

@@ -80,6 +80,21 @@ static struct media *media_find(const char *name)
 	return NULL;
 }
 
+/**
+ * media_find_id - locates specified media object by type identifier
+ */
+
+static struct media *media_find_id(u8 type)
+{
+	u32 i;
+
+	for (i = 0; i < media_count; i++) {
+		if (media_list[i].type_id == type)
+			return &media_list[i];
+	}
+	return NULL;
+}
+
 /**
  * tipc_register_media - register a media type
  *
@@ -88,8 +103,6 @@ static struct media *media_find(const char *name)
 
 int  tipc_register_media(struct media *m_ptr)
 {
-	u32 media_id;
-	u32 i;
 	int res = -EINVAL;
 
 	write_lock_bh(&tipc_net_lock);
@@ -121,29 +134,18 @@ int  tipc_register_media(struct media *m_ptr)
 		goto exit;
 	}
 
-	media_id = media_count++;
-	if (media_id >= MAX_MEDIA) {
+	if (media_count >= MAX_MEDIA) {
 		warn("Media <%s> rejected, media limit reached (%u)\n",
 		     m_ptr->name, MAX_MEDIA);
-		media_count--;
 		goto exit;
 	}
-	for (i = 0; i < media_id; i++) {
-		if (media_list[i].type_id == m_ptr->type_id) {
-			warn("Media <%s> rejected, duplicate type (%u)\n",
-			     m_ptr->name, m_ptr->type_id);
-			media_count--;
-			goto exit;
-		}
-		if (!strcmp(m_ptr->name, media_list[i].name)) {
-			warn("Media <%s> rejected, duplicate name\n",
-			     m_ptr->name);
-			media_count--;
-			goto exit;
-		}
+	if (media_find(m_ptr->name) || media_find_id(m_ptr->type_id)) {
+		warn("Media <%s> rejected, already registered\n", m_ptr->name);
+		goto exit;
 	}
 
-	media_list[media_id] = *m_ptr;
+	media_list[media_count] = *m_ptr;
+	media_count++;
 	res = 0;
 exit:
 	write_unlock_bh(&tipc_net_lock);