RDS: Do not set op_active in r_m_copy_from_user().

Do not allocate sgs for data for 0-length datagrams

Set data.op_active in rds_sendmsg() instead of
rds_message_copy_from_user().

Signed-off-by: Andy Grover <andy.grover@oracle.com>

2 files changed, 8 insertions, 7 deletions

diff --git a/net/rds/message.c b/net/rds/message.c
index 4bd9504ca048..f4c3be0878e9 100644
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -330,8 +330,6 @@ int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
                         sg++;
         }
 
-        rm->data.op_active = 1;
-
 out:
         return ret;
 }
diff --git a/net/rds/send.c b/net/rds/send.c
index 66dc6b045261..ad89a63c4304 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -970,11 +970,14 @@ int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
                 goto out;
         }
 
-        rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
-        /* XXX fix this to not allocate memory */
-        ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
-        if (ret)
-                goto out;
+        /* Attach data to the rm */
+        if (payload_len) {
+                rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
+                ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
+                if (ret)
+                        goto out;
+        }
+        rm->data.op_active = 1;
 
         rm->m_daddr = daddr;