From patchwork Wed Aug 10 08:39:42 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 1052072 X-Patchwork-Delegate: ericvh@gmail.com Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p7A8eFIt030424 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 10 Aug 2011 08:40:37 GMT Received: from localhost ([127.0.0.1] helo=sfs-ml-1.v29.ch3.sourceforge.com) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Qr4KR-0004dn-Ez; Wed, 10 Aug 2011 08:39:55 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Qr4KQ-0004dR-Mn for v9fs-developer@lists.sourceforge.net; Wed, 10 Aug 2011 08:39:54 +0000 X-ACL-Warn: Received: from e23smtp07.au.ibm.com ([202.81.31.140]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1Qr4KP-0001oq-Hz for v9fs-developer@lists.sourceforge.net; Wed, 10 Aug 2011 08:39:54 +0000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.31.245]) by e23smtp07.au.ibm.com (8.14.4/8.13.1) with ESMTP id p7A8dktp025524 for ; Wed, 10 Aug 2011 18:39:46 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p7A8dkbD1638596 for ; Wed, 10 Aug 2011 18:39:46 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p7A8dktF018447 for ; Wed, 10 Aug 2011 18:39:46 +1000 Received: from skywalker.in.ibm.com ([9.124.35.49]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p7A8dijK018412; Wed, 10 Aug 2011 18:39:45 +1000 From: "Aneesh Kumar K.V" To: v9fs-developer@lists.sourceforge.net Date: Wed, 10 Aug 2011 14:09:42 +0530 Message-Id: <1312965582-19538-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.4.1 X-Spam-Score: 0.2 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.8 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 1.1 AWL AWL: From: address is in the auto white-list X-Headers-End: 1Qr4KP-0001oq-Hz Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [V9fs-developer] [PATCH] net/9p: Fix kernel crash with msize 512K 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]); Wed, 10 Aug 2011 08:40:37 +0000 (UTC) With msize equal to 512K (PAGE_SIZE * VIRTQUEUE_NUM), we hit multiple crashes. This patch fix those. Signed-off-by: Aneesh Kumar K.V --- net/9p/trans_virtio.c | 12 +++++++++--- 1 files changed, 9 insertions(+), 3 deletions(-) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index e03cde0..ffebb6c 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -256,7 +256,7 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req) int in, out; unsigned long flags; struct virtio_chan *chan = client->trans; - char *rdata = (char *)req->rc+sizeof(struct p9_fcall); + char *rdata = (char *)req->rc + sizeof(struct p9_fcall); P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n"); @@ -269,7 +269,7 @@ req_retry_pinned: req->tc->size); in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM, - rdata, req->rc->capacity); + rdata, req->rc->capacity - sizeof(struct p9_fcall)); err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc); if (err < 0) { @@ -665,7 +665,13 @@ static struct p9_trans_module p9_virtio_trans = { .request = p9_virtio_request, .zc_request = p9_virtio_zc_request, .cancel = p9_virtio_cancel, - .maxsize = PAGE_SIZE*VIRTQUEUE_NUM, + /* + * We leave one entry for input and one entry for response + * headers. We also skip one more entry to accomodate, address + * that are not at page boundary, that can result in an extra + * page in zero copy. + */ + .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3), .def = 0, .owner = THIS_MODULE, };