Merge tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel

[linux.git] / net / 9p / client.c

diff --git a/net/9p/client.c b/net/9p/client.c
index 9186550d77a61b84c8f310ad7cd8e602ed116980..0004cbaac4a41d9737e017e257c9083df4969b8a 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -415,9 +415,17 @@ static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
  * req: request received
  *
  */
-void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 {
        p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
+
+       /*
+        * This barrier is needed to make sure any change made to req before
+        * the other thread wakes up will indeed be seen by the waiting side.
+        */
+       smp_wmb();
+       req->status = status;
+
        wake_up(req->wq);
        p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 }
@@ -655,16 +663,13 @@ static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
        if (IS_ERR(req))
                return PTR_ERR(req);
 
-
        /*
         * if we haven't received a response for oldreq,
         * remove it from the list
         */
-       if (oldreq->status == REQ_STATUS_FLSH) {
-               spin_lock(&c->lock);
-               list_del(&oldreq->req_list);
-               spin_unlock(&c->lock);
-       }
+       if (oldreq->status == REQ_STATUS_SENT)
+               if (c->trans_mod->cancelled)
+                       c->trans_mod->cancelled(c, oldreq);
 
        p9_free_req(c, req);
        return 0;
@@ -751,6 +756,12 @@ again:
        err = wait_event_interruptible(*req->wq,
                                       req->status >= REQ_STATUS_RCVD);
 
+       /*
+        * Make sure our req is coherent with regard to updates in other
+        * threads - echoes to wmb() in the callback
+        */
+       smp_rmb();
+
        if ((err == -ERESTARTSYS) && (c->status == Connected)
                                  && (type == P9_TFLUSH)) {
                sigpending = 1;