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: Zefan Li <lizefan@huawei.com>

diff --git a/net/9p/client.c b/net/9p/client.c
index b23a17c431c87ae8ae3c000349ad52f048286bff..32df0a3de2772267d026328154f5d400ae2331ce 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -833,7 +833,8 @@ 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);