RDS: use get_user_pages_fast()

Use the new function that is simpler and faster.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds/info.c

@@ -188,10 +188,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval,
 		ret = -ENOMEM;
 		goto out;
 	}
-	down_read(&current->mm->mmap_sem);
-	ret = get_user_pages(current, current->mm, start, nr_pages, 1, 0,
-			     pages, NULL);
-	up_read(&current->mm->mmap_sem);
+	ret = get_user_pages_fast(start, nr_pages, 1, pages);
 	if (ret != nr_pages) {
 		if (ret > 0)
 			nr_pages = ret;

net/rds/rdma.c

@@ -150,10 +150,7 @@ static int rds_pin_pages(unsigned long user_addr, unsigned int nr_pages,
 {
 	int ret;
 
-	down_read(&current->mm->mmap_sem);
-	ret = get_user_pages(current, current->mm, user_addr,
-			     nr_pages, write, 0, pages, NULL);
-	up_read(&current->mm->mmap_sem);
+	ret = get_user_pages_fast(user_addr, nr_pages, write, pages);
 
 	if (ret >= 0 && ret < nr_pages) {
 		while (ret--)