9p: make rpc code common and rework flush code

This code moves the rpc function to the common client base,
reorganizes the flush code to be more simple and stable, and
makes the necessary adjustments to the underlying transports
to adapt to the new structure.

This reduces the overall amount of code duplication between the
transports and should make adding new transports more straightforward.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 24 insertions, 61 deletions

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index e18de14..2d7781e 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -126,17 +126,16 @@ static void req_done(struct virtqueue *vq)
 	struct virtio_chan *chan = vq->vdev->priv;
 	struct p9_fcall *rc;
 	unsigned int len;
-	unsigned long flags;
 	struct p9_req_t *req;
 
-	spin_lock_irqsave(&chan->lock, flags);
+	P9_DPRINTK(P9_DEBUG_TRANS, ": request done\n");
+
 	while ((rc = chan->vq->vq_ops->get_buf(chan->vq, &len)) != NULL) {
+		P9_DPRINTK(P9_DEBUG_TRANS, ": rc %p\n", rc);
+		P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);
 		req = p9_tag_lookup(chan->client, rc->tag);
-		req->status = REQ_STATUS_RCVD;
-		wake_up(req->wq);
+		p9_client_cb(chan->client, req);
 	}
-	/* In case queue is stopped waiting for more buffers. */
-	spin_unlock_irqrestore(&chan->lock, flags);
 }
 
 /**
@@ -173,8 +172,14 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data,
 	return index-start;
 }
 
+/* We don't currently allow canceling of virtio requests */
+static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
+{
+	return 1;
+}
+
 /**
- * p9_virtio_rpc - issue a request and wait for a response
+ * p9_virtio_request - issue a request
  * @t: transport state
  * @tc: &p9_fcall request to transmit
  * @rc: &p9_fcall to put reponse into
@@ -182,44 +187,22 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data,
  */
 
 static int
-p9_virtio_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
+p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 {
 	int in, out;
-	int n, err, size;
-	struct virtio_chan *chan = c->trans;
-	char *rdata;
-	struct p9_req_t *req;
-	unsigned long flags;
-
-	if (*rc == NULL) {
-		*rc = kmalloc(sizeof(struct p9_fcall) + c->msize, GFP_KERNEL);
-		if (!*rc)
-			return -ENOMEM;
-	}
-
-	rdata = (char *)*rc+sizeof(struct p9_fcall);
-
-	n = P9_NOTAG;
-	if (tc->id != P9_TVERSION) {
-		n = p9_idpool_get(c->tagpool);
-		if (n < 0)
-			return -ENOMEM;
-	}
-
-	spin_lock_irqsave(&chan->lock, flags);
-	req = p9_tag_alloc(c, n);
-	spin_unlock_irqrestore(&chan->lock, flags);
-
-	p9_set_tag(tc, n);
+	struct virtio_chan *chan = client->trans;
+	char *rdata = (char *)req->rc+sizeof(struct p9_fcall);
 
-	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc tag %d\n", n);
+	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n");
 
-	out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, tc->sdata, tc->size);
-	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, c->msize);
+	out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, req->tc->sdata,
+								req->tc->size);
+	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata,
+								client->msize);
 
 	req->status = REQ_STATUS_SENT;
 
-	if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, tc)) {
+	if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc)) {
 		P9_DPRINTK(P9_DEBUG_TRANS,
 			"9p debug: virtio rpc add_buf returned failure");
 		return -EIO;
@@ -227,28 +210,7 @@ p9_virtio_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
 
 	chan->vq->vq_ops->kick(chan->vq);
 
-	wait_event(*req->wq, req->status == REQ_STATUS_RCVD);
-
-	size = le32_to_cpu(*(__le32 *) rdata);
-
-	err = p9_deserialize_fcall(rdata, size, *rc, c->dotu);
-	if (err < 0) {
-		P9_DPRINTK(P9_DEBUG_TRANS,
-			"9p debug: virtio rpc deserialize returned %d\n", err);
-		return err;
-	}
-
-#ifdef CONFIG_NET_9P_DEBUG
-	if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
-		char buf[150];
-
-		p9_printfcall(buf, sizeof(buf), *rc, c->dotu);
-		printk(KERN_NOTICE ">>> %p %s\n", c, buf);
-	}
-#endif
-
-	p9_free_req(c, req);
-
+	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");
 	return 0;
 }
 
@@ -394,7 +356,8 @@ static struct p9_trans_module p9_virtio_trans = {
 	.name = "virtio",
 	.create = p9_virtio_create,
 	.close = p9_virtio_close,
-	.rpc = p9_virtio_rpc,
+	.request = p9_virtio_request,
+	.cancel = p9_virtio_cancel,
 	.maxsize = PAGE_SIZE*16,
 	.def = 0,
 	.owner = THIS_MODULE,