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@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/9p/client.c b/net/9p/client.c
index 854ca7a911c427f753ebe2b5d93a71a1c10df041..e95817801fc7f24c4b582b3948aa6fa8080f908c 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -824,7 +824,8 @@ 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_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);