From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:53106)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <stefanha@gmail.com>) id 1Wsu10-0000x6-IG
	for qemu-devel@nongnu.org; Fri, 06 Jun 2014 09:17:11 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <stefanha@gmail.com>) id 1Wsu0r-0006zk-HX
	for qemu-devel@nongnu.org; Fri, 06 Jun 2014 09:17:02 -0400
Received: from mail-we0-x22a.google.com ([2a00:1450:400c:c03::22a]:62352)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <stefanha@gmail.com>) id 1Wsu0r-0006zZ-BI
	for qemu-devel@nongnu.org; Fri, 06 Jun 2014 09:16:53 -0400
Received: by mail-we0-f170.google.com with SMTP id u57so2854791wes.15
	for <qemu-devel@nongnu.org>; Fri, 06 Jun 2014 06:16:52 -0700 (PDT)
Date: Fri, 6 Jun 2014 15:16:49 +0200
From: Stefan Hajnoczi <stefanha@gmail.com>
Message-ID: <20140606131649.GE14322@stefanha-thinkpad>
References: <1402019610-2985-1-git-send-email-famz@redhat.com>
	<1402019610-2985-10-git-send-email-famz@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1402019610-2985-10-git-send-email-famz@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v3 9/9] virtio-blk: Fix and clean up the
 in_sg and out_sg check
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Fam Zheng <famz@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>

On Fri, Jun 06, 2014 at 09:53:30AM +0800, Fam Zheng wrote:
> @@ -353,19 +355,18 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req,
>          exit(1);
>      }
>  
> -    if (req->elem->out_sg[0].iov_len < sizeof(req->out) ||
> -        req->elem->in_sg[req->elem->in_num - 1].iov_len < sizeof(*req->in)) {
> -        error_report("virtio-blk header not in correct element");
> -        exit(1);
> -    }
> -
>      if (unlikely(iov_to_buf(iov, out_num, 0, &req->out,
>                              sizeof(req->out)) != sizeof(req->out))) {
>          error_report("virtio-blk request outhdr too short");
>          exit(1);
>      }
>      iov_discard_front(&iov, &out_num, sizeof(req->out));
> -    req->in = (void *)req->elem->in_sg[req->elem->in_num - 1].iov_base;
> +    assert(in_iov[in_num - 1].iov_len >=
> +           sizeof(struct virtio_blk_inhdr));

Why use assert() when the rest of the function uses error_report() +
exit(1)?  Please keep the code consistent.