9p/trans_virtio.c: use virtio_add_sgs[]

virtio_add_buf() is going away, replaced with virtio_add_sgs() which
takes multiple terminated scatterlists.

Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 74dea37..568d1c9 100644 (file)
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -194,11 +194,14 @@ static int pack_sg_list(struct scatterlist *sg, int start,
                if (s > count)
                        s = count;
                BUG_ON(index > limit);
+               /* Make sure we don't terminate early. */
+               sg_unmark_end(&sg[index]);
                sg_set_buf(&sg[index++], data, s);
                count -= s;
                data += s;
        }
-
+       if (index-start)
+               sg_mark_end(&sg[index - 1]);
        return index-start;
 }
 
@@ -236,12 +239,17 @@ pack_sg_list_p(struct scatterlist *sg, int start, int limit,
                s = rest_of_page(data);
                if (s > count)
                        s = count;
+               /* Make sure we don't terminate early. */
+               sg_unmark_end(&sg[index]);
                sg_set_page(&sg[index++], pdata[i++], s, data_off);
                data_off = 0;
                data += s;
                count -= s;
                nr_pages--;
        }
+
+       if (index-start)
+               sg_mark_end(&sg[index - 1]);
        return index - start;
 }
 
@@ -256,9 +264,10 @@ static int
 p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 {
        int err;
-       int in, out;
+       int in, out, out_sgs, in_sgs;
        unsigned long flags;
        struct virtio_chan *chan = client->trans;
+       struct scatterlist *sgs[2];
 
        p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
 
@@ -266,14 +275,19 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 req_retry:
        spin_lock_irqsave(&chan->lock, flags);
 
+       out_sgs = in_sgs = 0;
        /* Handle out VirtIO ring buffers */
        out = pack_sg_list(chan->sg, 0,
                           VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
+       if (out)
+               sgs[out_sgs++] = chan->sg;
 
        in = pack_sg_list(chan->sg, out,
                          VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
+       if (in)
+               sgs[out_sgs + in_sgs++] = chan->sg + out;
 
-       err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc,
+       err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
                                GFP_ATOMIC);
        if (err < 0) {
                if (err == -ENOSPC) {
@@ -289,7 +303,7 @@ req_retry:
                } else {
                        spin_unlock_irqrestore(&chan->lock, flags);
                        p9_debug(P9_DEBUG_TRANS,
-                                "virtio rpc add_buf returned failure\n");
+                                "virtio rpc add_sgs returned failure\n");
                        return -EIO;
                }
        }
@@ -351,11 +365,12 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
                     char *uidata, char *uodata, int inlen,
                     int outlen, int in_hdr_len, int kern_buf)
 {
-       int in, out, err;
+       int in, out, err, out_sgs, in_sgs;
        unsigned long flags;
        int in_nr_pages = 0, out_nr_pages = 0;
        struct page **in_pages = NULL, **out_pages = NULL;
        struct virtio_chan *chan = client->trans;
+       struct scatterlist *sgs[4];
 
        p9_debug(P9_DEBUG_TRANS, "virtio request\n");
 
@@ -396,13 +411,22 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
        req->status = REQ_STATUS_SENT;
 req_retry_pinned:
        spin_lock_irqsave(&chan->lock, flags);
+
+       out_sgs = in_sgs = 0;
+
        /* out data */
        out = pack_sg_list(chan->sg, 0,
                           VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
 
-       if (out_pages)
+       if (out)
+               sgs[out_sgs++] = chan->sg;
+
+       if (out_pages) {
+               sgs[out_sgs++] = chan->sg + out;
                out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
                                      out_pages, out_nr_pages, uodata, outlen);
+       }
+               
        /*
         * Take care of in data
         * For example TREAD have 11.
@@ -412,11 +436,17 @@ req_retry_pinned:
         */
        in = pack_sg_list(chan->sg, out,
                          VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
-       if (in_pages)
+       if (in)
+               sgs[out_sgs + in_sgs++] = chan->sg + out;
+
+       if (in_pages) {
+               sgs[out_sgs + in_sgs++] = chan->sg + out + in;
                in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
                                     in_pages, in_nr_pages, uidata, inlen);
+       }
 
-       err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc,
+       BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
+       err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
                                GFP_ATOMIC);
        if (err < 0) {
                if (err == -ENOSPC) {
@@ -432,7 +462,7 @@ req_retry_pinned:
                } else {
                        spin_unlock_irqrestore(&chan->lock, flags);
                        p9_debug(P9_DEBUG_TRANS,
-                                "virtio rpc add_buf returned failure\n");
+                                "virtio rpc add_sgs returned failure\n");
                        err = -EIO;
                        goto err_out;
                }