From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Venkateswararao Jujjuri (JV)" Subject: [RFC] [PATCH 1/7] [net/9p] Additional elements to p9_fcall to accomodate zero copy. Date: Sun, 6 Feb 2011 23:21:20 -0800 Message-ID: <1297063283-2180-5-git-send-email-jvrao@linux.vnet.ibm.com> References: <1297063283-2180-1-git-send-email-jvrao@linux.vnet.ibm.com> Cc: linux-fsdevel@vger.kernel.org, "Venkateswararao Jujjuri (JV)" To: v9fs-developer@lists.sourceforge.net Return-path: Received: from e4.ny.us.ibm.com ([32.97.182.144]:47089 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752514Ab1BGGoc (ORCPT ); Mon, 7 Feb 2011 01:44:32 -0500 Received: from d01dlp01.pok.ibm.com (d01dlp01.pok.ibm.com [9.56.224.56]) by e4.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p176Pr3F001115 for ; Mon, 7 Feb 2011 01:26:00 -0500 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 8FAB172804B for ; Mon, 7 Feb 2011 01:44:25 -0500 (EST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p176iOVf163294 for ; Mon, 7 Feb 2011 01:44:25 -0500 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p176iOCA018117 for ; Sun, 6 Feb 2011 23:44:24 -0700 In-Reply-To: <1297063283-2180-1-git-send-email-jvrao@linux.vnet.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Signed-off-by: Venkateswararao Jujjuri --- net/9p/trans_virtio.c | 85 +++++++++++++++++++++++++++++++++++++++++++++--- 1 files changed, 79 insertions(+), 6 deletions(-) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index c8f3f72..607f064 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -45,6 +45,7 @@ #include #include #include +#include "trans_common.h" #define VIRTQUEUE_NUM 128 @@ -155,6 +156,12 @@ static void req_done(struct virtqueue *vq) rc->tag); req = p9_tag_lookup(chan->client, rc->tag); req->status = REQ_STATUS_RCVD; + if (req->tc->private) { + /*Release pages */ + p9_release_req_pages(req->tc->private); + kfree(req->tc->private); + req->tc->private = NULL; + } p9_client_cb(chan->client, req); } else { spin_unlock_irqrestore(&chan->lock, flags); @@ -202,6 +209,30 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) return 1; } +static int +pack_sg_list_p(struct scatterlist *sg, int start, int limit, size_t pdata_off, + struct page **pdata, int count) +{ + int s; + int i = 0; + int index = start; + + if (pdata_off) { + s = min((int)(PAGE_SIZE - pdata_off), count); + sg_set_page(&sg[index++], pdata[i++], s, pdata_off); + count -= s; + } + + while (count) { + BUG_ON(index > limit); + s = min((int)PAGE_SIZE, count); + sg_set_page(&sg[index++], pdata[i++], s, 0); + count -= s; + } + + return index-start; +} + /** * p9_virtio_request - issue a request * @client: client instance issuing the request @@ -212,22 +243,64 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) static int p9_virtio_request(struct p9_client *client, struct p9_req_t *req) { - int in, out; + int in, out, inp, outp; struct virtio_chan *chan = client->trans; char *rdata = (char *)req->rc+sizeof(struct p9_fcall); unsigned long flags; - int err; + size_t pdata_off=0; + virtio_rpage_info_t *rpinfo; + int err, pdata_len=0; P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n"); req_retry: req->status = REQ_STATUS_SENT; + if (req->tc->pbuf_size && + (req->tc->pbuf && !segment_eq(get_fs(), KERNEL_DS))) { + err = payload_gup(req, &pdata_off, &pdata_len, + req->tc->id == P9_TREAD ? 1 : 0 ); + if (err < 0) + return err; + } + rpinfo = (virtio_rpage_info_t *)req->tc->private; + 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); + + /* Handle out VirtIO ring buffers */ + if (req->tc->pbuf_size && (req->tc->id == P9_TWRITE)) { + /* We have additional write payload buffer to take care */ + out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, req->tc->sdata, + req->tc->size); + outp = pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM, + pdata_off, rpinfo->vp_data, pdata_len); + out += outp; + } else { + out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, req->tc->sdata, + req->tc->size); + } + + /* Handle in VirtIO ring buffers */ + if (req->tc->pbuf_size && (req->tc->id == P9_TREAD)) { + /* We have additional Read payload buffer to take care */ + inp = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, rdata, 11); + /* + * Running executables in the filesystem may result in + * a read request with kernel buffer as opposed to user buffer. + */ + if (req->tc->pbuf && !segment_eq(get_fs(), KERNEL_DS)) { + in = pack_sg_list_p(chan->sg, out+inp, VIRTQUEUE_NUM, + pdata_off, rpinfo->vp_data, pdata_len); + } else { + in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, + (char *)req->tc->pbuf, + req->tc->pbuf_size); + } + in += inp; + } else { + in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, rdata, + client->msize); + } err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc); if (err < 0) { -- 1.6.5.2