rds: Make rds_message_copy_from_user() return 0 on success.

Commit 083735f4b01b ("rds: switch rds_message_copy_from_user() to iov_iter")
breaks rds_message_copy_from_user() semantics on success, and causes it
to return nbytes copied, when it should return 0.  This commit fixes that bug.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/rds/message.c b/net/rds/message.c
index 5a21e6f5986f1b822e41077f54f5f6235fe47068..756c73729126d45c18a29bd5859aa04596a1ed0f 100644 (file)
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -266,7 +266,7 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
 
 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from)
 {
-       unsigned long to_copy;
+       unsigned long to_copy, nbytes;
        unsigned long sg_off;
        struct scatterlist *sg;
        int ret = 0;
@@ -293,9 +293,9 @@ int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from)
                                sg->length - sg_off);
 
                rds_stats_add(s_copy_from_user, to_copy);
-               ret = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
-                                         to_copy, from);
-               if (ret != to_copy)
+               nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
+                                            to_copy, from);
+               if (nbytes != to_copy)
                        return -EFAULT;
 
                sg_off += to_copy;