[3.16.y-ckt stable] Patch "9p: forgetting to cancel request on interrupted zero-copy RPC" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    9p: forgetting to cancel request on interrupted zero-copy RPC

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt15.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 73a0766834dbe8109e403520a93d22e473ddc6c2 Mon Sep 17 00:00:00 2001
From: Al Viro <viro at zeniv.linux.org.uk>
Date: Sat, 4 Jul 2015 16:04:19 -0400
Subject: 9p: forgetting to cancel request on interrupted zero-copy RPC

commit a84b69cb6e0a41e86bc593904faa6def3b957343 upstream.

If we'd already sent a request and decide to abort it, we *must*
issue TFLUSH properly and not just blindly reuse the tag, or
we'll get seriously screwed when response eventually arrives
and we confuse it for response to later request that had reused
the same tag.

Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/9p/client.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/9p/client.c b/net/9p/client.c
index 0004cbaac4a4..55a55ce92dc1 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -850,7 +850,8 @@ static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 	if (err < 0) {
 		if (err == -EIO)
 			c->status = Disconnected;
-		goto reterr;
+		if (err != -ERESTARTSYS)
+			goto reterr;
 	}
 	if (req->status == REQ_STATUS_ERROR) {
 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);