[RFC 15/15] net/rds: rds_sendmsg should not discard payload_len

[Allison Henderson <achender@kernel.org>]

From: Allison Henderson <allison.henderson@oracle.com>

Commit 3db6e0d172c9 ("rds: use RCU to synchronize work-enqueue with
connection teardown") modifies rds_sendmsg to avoid enqueueing work
while a tear down is in progress. However, it also changed the return
value of rds_sendmsg to that of rds_send_xmit instead of the
payload_len. This means the user may incorrectly receive errno values
when it should have simply received a payload of 0 while the peer
attempts a reconnections.  So this patch corrects the teardown handling
code to only use the out error path in that case, thus restoring the
original payload_len return value.

Fixes: 3db6e0d172c9 ("rds: use RCU to synchronize work-enqueue with connection teardown")
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
 net/rds/send.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/rds/send.c b/net/rds/send.c
index 8b051f1dfc6a..3d0d914eb027 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -1418,9 +1418,11 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 		else
 			queue_delayed_work(cpath->cp_wq, &cpath->cp_send_w, 1);
 		rcu_read_unlock();
+
+		if (ret)
+			goto out;
 	}
-	if (ret)
-		goto out;
+
 	rds_message_put(rm);
 
 	for (ind = 0; ind < vct.indx; ind++)
-- 
2.43.0