fs: dlm: use GFP_ZERO for page buffer

This patch uses GFP_ZERO for allocate a page for the internal dlm
sending buffer allocator instead of calling memset zero after every
allocation. An already allocated space will never be reused again.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lock.c

@@ -3541,8 +3541,6 @@ static int _create_message(struct dlm_ls *ls, int mb_len,
 	if (!mh)
 		return -ENOBUFS;
 
-	memset(mb, 0, mb_len);
-
 	ms = (struct dlm_message *) mb;
 
 	ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);

fs/dlm/lowcomms.c

@@ -1355,7 +1355,7 @@ static struct writequeue_entry *new_writequeue_entry(struct connection *con,
 	if (!entry)
 		return NULL;
 
-	entry->page = alloc_page(allocation);
+	entry->page = alloc_page(allocation | __GFP_ZERO);
 	if (!entry->page) {
 		kfree(entry);
 		return NULL;

fs/dlm/rcom.c

@@ -41,7 +41,6 @@ static int create_rcom(struct dlm_ls *ls, int to_nodeid, int type, int len,
 			  to_nodeid, type, len);
 		return -ENOBUFS;
 	}
-	memset(mb, 0, mb_len);
 
 	rc = (struct dlm_rcom *) mb;
 
@@ -462,7 +461,6 @@ int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
 	mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
 	if (!mh)
 		return -ENOBUFS;
-	memset(mb, 0, mb_len);
 
 	rc = (struct dlm_rcom *) mb;