[net/9p]Serialize virtqueue operations to make VirtIO transport SMP safe.
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index b885159..8ae0859 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -134,16 +134,24 @@
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) {
- 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;
- p9_client_cb(chan->client, req);
- }
+ 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);
+ 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 @@
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;