dlm: convert connections_lock in a mutex

The semaphore connections_lock is used as a mutex.  Convert it to the mutex
API.

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lowcomms.c

@@ -50,6 +50,7 @@
 #include <linux/pagemap.h>
 #include <linux/idr.h>
 #include <linux/file.h>
+#include <linux/mutex.h>
 #include <linux/sctp.h>
 #include <net/sctp/user.h>
 
@@ -138,7 +139,7 @@ static struct workqueue_struct *recv_workqueue;
 static struct workqueue_struct *send_workqueue;
 
 static DEFINE_IDR(connections_idr);
-static DECLARE_MUTEX(connections_lock);
+static DEFINE_MUTEX(connections_lock);
 static int max_nodeid;
 static struct kmem_cache *con_cache;
 
@@ -205,9 +206,9 @@ static struct connection *nodeid2con(int nodeid, gfp_t allocation)
 {
 	struct connection *con;
 
-	down(&connections_lock);
+	mutex_lock(&connections_lock);
 	con = __nodeid2con(nodeid, allocation);
-	up(&connections_lock);
+	mutex_unlock(&connections_lock);
 
 	return con;
 }
@@ -218,15 +219,15 @@ static struct connection *assoc2con(int assoc_id)
 	int i;
 	struct connection *con;
 
-	down(&connections_lock);
+	mutex_lock(&connections_lock);
 	for (i=0; i<=max_nodeid; i++) {
 		con = __nodeid2con(i, 0);
 		if (con && con->sctp_assoc == assoc_id) {
-			up(&connections_lock);
+			mutex_unlock(&connections_lock);
 			return con;
 		}
 	}
-	up(&connections_lock);
+	mutex_unlock(&connections_lock);
 	return NULL;
 }
 
@@ -381,7 +382,7 @@ static void sctp_init_failed(void)
 	int i;
 	struct connection *con;
 
-	down(&connections_lock);
+	mutex_lock(&connections_lock);
 	for (i=1; i<=max_nodeid; i++) {
 		con = __nodeid2con(i, 0);
 		if (!con)
@@ -393,7 +394,7 @@ static void sctp_init_failed(void)
 			}
 		}
 	}
-	up(&connections_lock);
+	mutex_unlock(&connections_lock);
 }
 
 /* Something happened to an association */
@@ -1417,7 +1418,7 @@ void dlm_lowcomms_stop(void)
 	/* Set all the flags to prevent any
 	   socket activity.
 	*/
-	down(&connections_lock);
+	mutex_lock(&connections_lock);
 	for (i = 0; i <= max_nodeid; i++) {
 		con = __nodeid2con(i, 0);
 		if (con) {
@@ -1426,11 +1427,11 @@ void dlm_lowcomms_stop(void)
 				con->sock->sk->sk_user_data = NULL;
 		}
 	}
-	up(&connections_lock);
+	mutex_unlock(&connections_lock);
 
 	work_stop();
 
-	down(&connections_lock);
+	mutex_lock(&connections_lock);
 	clean_writequeues();
 
 	for (i = 0; i <= max_nodeid; i++) {
@@ -1443,7 +1444,7 @@ void dlm_lowcomms_stop(void)
 		}
 	}
 	max_nodeid = 0;
-	up(&connections_lock);
+	mutex_unlock(&connections_lock);
 	kmem_cache_destroy(con_cache);
 	idr_init(&connections_idr);
 }