From patchwork Fri Feb 11 01:25:08 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: jvrao X-Patchwork-Id: 548451 X-Patchwork-Delegate: ericvh@gmail.com Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p1B0lqHU023961 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Fri, 11 Feb 2011 00:48:13 GMT Received: from localhost ([127.0.0.1] helo=sfs-ml-3.v29.ch3.sourceforge.com) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.74) (envelope-from ) id 1PnhAb-0003e6-SL; Fri, 11 Feb 2011 00:47:33 +0000 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.74) (envelope-from ) id 1PnhAb-0003du-1U for v9fs-developer@lists.sourceforge.net; Fri, 11 Feb 2011 00:47:33 +0000 X-ACL-Warn: Received: from e35.co.us.ibm.com ([32.97.110.153]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.74) id 1PnhAZ-00058x-UD for v9fs-developer@lists.sourceforge.net; Fri, 11 Feb 2011 00:47:33 +0000 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e35.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p1B0XDu3003626 for ; Thu, 10 Feb 2011 17:33:13 -0700 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p1B0lQ6K107148 for ; Thu, 10 Feb 2011 17:47:26 -0700 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 p1B0lP8t028081 for ; Thu, 10 Feb 2011 17:47:25 -0700 Received: from localhost.localdomain (elm3c187.beaverton.ibm.com [9.47.69.187]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p1B0lM9E027941; Thu, 10 Feb 2011 17:47:24 -0700 From: "Venkateswararao Jujjuri (JV)" To: v9fs-developer@lists.sourceforge.net Date: Thu, 10 Feb 2011 17:25:08 -0800 Message-Id: <1297387511-2697-5-git-send-email-jvrao@linux.vnet.ibm.com> X-Mailer: git-send-email 1.6.0.6 In-Reply-To: <1297387511-2697-1-git-send-email-jvrao@linux.vnet.ibm.com> References: <1297387511-2697-1-git-send-email-jvrao@linux.vnet.ibm.com> X-Spam-Score: -0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Headers-End: 1PnhAZ-00058x-UD Cc: linux-fsdevel@vger.kernel.org Subject: [V9fs-developer] [RFC-V3 4/7] [net/9p] Add gup/zero_copy support to VirtIO transport layer. X-BeenThere: v9fs-developer@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: v9fs-developer-bounces@lists.sourceforge.net X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Fri, 11 Feb 2011 00:48:13 +0000 (UTC) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index c8f3f72..e0c301f 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 +156,14 @@ 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) { + struct trans_rpage_info *rp = req->tc->private; + /*Release pages */ + p9_release_req_pages(rp); + if (rp->rp_alloc) + kfree(rp); + req->tc->private = NULL; + } p9_client_cb(chan->client, req); } else { spin_unlock_irqrestore(&chan->lock, flags); @@ -202,6 +211,30 @@ 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 +245,82 @@ 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; + struct trans_rpage_info *rpinfo = NULL; + 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->pubuf && !segment_eq(get_fs(), KERNEL_DS))) { + int nr_pages = p9_nr_pages(req); + int rpinfo_size = sizeof(struct trans_rpage_info) + + sizeof(struct page *) * nr_pages; + + if (rpinfo_size <= (req->tc->capacity - req->tc->size)) { + /* We can use sdata */ + req->tc->private = req->tc->sdata + req->tc->size; + rpinfo = (struct trans_rpage_info *)req->tc->private; + rpinfo->rp_alloc = 0; + } else { + req->tc->private = kmalloc(rpinfo_size, GFP_KERNEL); + rpinfo = (struct trans_rpage_info *)req->tc->private; + rpinfo->rp_alloc = 1; + } + + err = p9_payload_gup(req, &pdata_off, &pdata_len, nr_pages, + req->tc->id == P9_TREAD ? 1 : 0); + if (err < 0) { + if (rpinfo->rp_alloc) + kfree(rpinfo); + return err; + } + } + 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->rp_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->pubuf && !segment_eq(get_fs(), KERNEL_DS)) { + in = pack_sg_list_p(chan->sg, out+inp, VIRTQUEUE_NUM, + pdata_off, rpinfo->rp_data, pdata_len); + } else { + char *pbuf = req->tc->pubuf ? req->tc->pubuf : + req->tc->pkbuf; + in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, + 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) { @@ -246,6 +339,8 @@ req_retry: P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: " "virtio rpc add_buf returned failure"); + if (rpinfo && rpinfo->rp_alloc) + kfree(rpinfo); return -EIO; } }