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Commit 419b3956 authored by Venkateswararao Jujjuri (JV)'s avatar Venkateswararao Jujjuri (JV) Committed by Eric Van Hensbergen
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[net/9p]Serialize virtqueue operations to make VirtIO transport SMP safe. 



Signed-off-by: default avatarVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
parent 329176cc

net/9p/trans_virtio.c

+24 −10
Original line number Diff line number Diff line
@@ -134,16 +134,24 @@ static void req_done(struct virtqueue *vq) 
	struct p9_fcall *rc;

	unsigned int len;

	struct p9_req_t *req;

	unsigned long flags;



	P9_DPRINTK(P9_DEBUG_TRANS, ": request done\n");



	while ((rc = virtqueue_get_buf(chan->vq, &len)) != NULL) {

	do {

		spin_lock_irqsave(&chan->lock, flags);

		rc = virtqueue_get_buf(chan->vq, &len);

		spin_unlock_irqrestore(&chan->lock, flags);



		if (rc != NULL) {

			P9_DPRINTK(P9_DEBUG_TRANS, ": rc %p\n", rc);

		P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);

			P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n",

					rc->tag);

			req = p9_tag_lookup(chan->client, rc->tag);

			req->status = REQ_STATUS_RCVD;

			p9_client_cb(chan->client, req);

		}

	} while (rc != NULL);

}



/**
@@ -199,23 +207,29 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req) 
	int in, out;

	struct virtio_chan *chan = client->trans;

	char *rdata = (char *)req->rc+sizeof(struct p9_fcall);

	unsigned long flags;

	int err;



	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n");



	req->status = REQ_STATUS_SENT;



	spin_lock_irqsave(&chan->lock, flags);

	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 (virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc) < 0) {

	err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc);

	if (err < 0) {

		spin_unlock_irqrestore(&chan->lock, flags);

		P9_DPRINTK(P9_DEBUG_TRANS,

			"9p debug: virtio rpc add_buf returned failure");

		return -EIO;

	}



	virtqueue_kick(chan->vq);

	spin_unlock_irqrestore(&chan->lock, flags);



	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");

	return 0;