From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Venkateswararao Jujjuri (JV)" Subject: [PATCH 1/2] [RFC][net/9p]Serialize virtqueue operations to make VirtIO transport SMP safe. Date: Thu, 30 Sep 2010 12:41:56 -0700 Message-ID: <1285875717-13096-1-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]:49813 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755869Ab0I3T0C (ORCPT ); Thu, 30 Sep 2010 15:26:02 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e4.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id o8UJAKWP005842 for ; Thu, 30 Sep 2010 15:10:20 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o8UJQ023448982 for ; Thu, 30 Sep 2010 15:26:00 -0400 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 o8UJPwh6003656 for ; Thu, 30 Sep 2010 13:26:00 -0600 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Signed-off-by: Venkateswararao Jujjuri --- net/9p/trans_virtio.c | 34 ++++++++++++++++++++++++---------- 1 files changed, 24 insertions(+), 10 deletions(-) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index dcfbe99..0df84bf 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -134,16 +134,24 @@ static void req_done(struct virtqueue *vq) 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 @@ 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); + 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; -- 1.6.5.2