[PATCHv2] rds: Make rds_message_copy_from_user() return 0 on success.

From: Sowmini Varadhan
Date: Thu Feb 05 2015 - 17:41:56 EST




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@xxxxxxxxxx>
---
changes from v1: incorporate Al.Viro comment.

net/rds/message.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/rds/message.c b/net/rds/message.c
index 5a21e6f..756c737 100644
--- 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;
--
1.7.1

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