Exemple #1
0
static int
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);

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

	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, req->tc) < 0) {
		P9_DPRINTK(P9_DEBUG_TRANS,
			"9p debug: virtio rpc add_buf returned failure");
		return -EIO;
	}

	chan->vq->vq_ops->kick(chan->vq);

	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");
	return 0;
}
static int
p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
{
	int err;
	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");

	req->status = REQ_STATUS_SENT;
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_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
				GFP_ATOMIC);
	if (err < 0) {
		if (err == -ENOSPC) {
			chan->ring_bufs_avail = 0;
			spin_unlock_irqrestore(&chan->lock, flags);
			err = wait_event_interruptible(*chan->vc_wq,
							chan->ring_bufs_avail);
			if (err  == -ERESTARTSYS)
				return err;

			p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
			goto req_retry;
		} else {
			spin_unlock_irqrestore(&chan->lock, flags);
			p9_debug(P9_DEBUG_TRANS,
				 "virtio rpc add_sgs returned failure\n");
			return -EIO;
		}
	}
	virtqueue_kick(chan->vq);
	spin_unlock_irqrestore(&chan->lock, flags);

	p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
	return 0;
}
/**
 * p9_virtio_zc_request - issue a zero copy request
 * @client: client instance issuing the request
 * @req: request to be issued
 * @uidata: user bffer that should be ued for zero copy read
 * @uodata: user buffer that shoud be user for zero copy write
 * @inlen: read buffer size
 * @olen: write buffer size
 * @hdrlen: reader header size, This is the size of response protocol data
 *
 */
static int
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, 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");

	if (uodata) {
		out_nr_pages = p9_nr_pages(uodata, outlen);
		out_pages = kmalloc(sizeof(struct page *) * out_nr_pages,
				    GFP_NOFS);
		if (!out_pages) {
			err = -ENOMEM;
			goto err_out;
		}
		out_nr_pages = p9_get_mapped_pages(chan, out_pages, uodata,
						   out_nr_pages, 0, kern_buf);
		if (out_nr_pages < 0) {
			err = out_nr_pages;
			kfree(out_pages);
			out_pages = NULL;
			goto err_out;
		}
	}
	if (uidata) {
		in_nr_pages = p9_nr_pages(uidata, inlen);
		in_pages = kmalloc(sizeof(struct page *) * in_nr_pages,
				   GFP_NOFS);
		if (!in_pages) {
			err = -ENOMEM;
			goto err_out;
		}
		in_nr_pages = p9_get_mapped_pages(chan, in_pages, uidata,
						  in_nr_pages, 1, kern_buf);
		if (in_nr_pages < 0) {
			err = in_nr_pages;
			kfree(in_pages);
			in_pages = NULL;
			goto err_out;
		}
	}
	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)
		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.
	 * 11 is the read/write header = PDU Header(7) + IO Size (4).
	 * Arrange in such a way that server places header in the
	 * alloced memory and payload onto the user buffer.
	 */
	in = pack_sg_list(chan->sg, out,
			  VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
	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);
	}

	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) {
			chan->ring_bufs_avail = 0;
			spin_unlock_irqrestore(&chan->lock, flags);
			err = wait_event_interruptible(*chan->vc_wq,
						       chan->ring_bufs_avail);
			if (err  == -ERESTARTSYS)
				goto err_out;

			p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
			goto req_retry_pinned;
		} else {
			spin_unlock_irqrestore(&chan->lock, flags);
			p9_debug(P9_DEBUG_TRANS,
				 "virtio rpc add_sgs returned failure\n");
			err = -EIO;
			goto err_out;
		}
	}
	virtqueue_kick(chan->vq);
	spin_unlock_irqrestore(&chan->lock, flags);
	p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
	err = wait_event_interruptible(*req->wq,
				       req->status >= REQ_STATUS_RCVD);
	/*
	 * Non kernel buffers are pinned, unpin them
	 */
err_out:
	if (!kern_buf) {
		if (in_pages) {
			p9_release_pages(in_pages, in_nr_pages);
			atomic_sub(in_nr_pages, &vp_pinned);
		}
		if (out_pages) {
			p9_release_pages(out_pages, out_nr_pages);
			atomic_sub(out_nr_pages, &vp_pinned);
		}
		/* wakeup anybody waiting for slots to pin pages */
		wake_up(&vp_wq);
	}
	kfree(in_pages);
	kfree(out_pages);
	return err;
}