From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:53577)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1aLV5r-0003tG-9f
	for qemu-devel@nongnu.org; Tue, 19 Jan 2016 07:09:06 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1aLV5q-0008BW-74
	for qemu-devel@nongnu.org; Tue, 19 Jan 2016 07:09:03 -0500
Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
References: <1453204208-10776-1-git-send-email-berrange@redhat.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <569E2753.8020607@redhat.com>
Date: Tue, 19 Jan 2016 13:08:51 +0100
MIME-Version: 1.0
In-Reply-To: <1453204208-10776-1-git-send-email-berrange@redhat.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH] nbd: use client_close() when negotiate
	phase fails
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: "Daniel P. Berrange" <berrange@redhat.com>, qemu-devel@nongnu.org
Cc: Fam Zheng <famz@redhat.com>, qemu-block@nongnu.org



On 19/01/2016 12:50, Daniel P. Berrange wrote:
> When nbd_negotiate() fails, nbd_co_client_start() is
> directly calling client->close(). This eventually
> ends up calling nbd_client_put(), which does an
> assert(client->closing). Unfortunately we have not
> set the 'closing' flag, so the code now aborts. This
> bug was accidentally introduced in
> 
>   commit ee7d7aabdaea4484e069cb99c9fc54e8cb24b56f
>   Author: Fam Zheng <famz@redhat.com>
>   Date:   Thu Jan 14 16:41:01 2016 +0800
> 
>     nbd: Always call "close_fn" in nbd_client_new
> 
> The simple fix is to not directly call client->close()
> but instead call the client_close() method, which
> takes care todo the right sequence of steps to close
> the client.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Good catch, thanks.

Paolo

> ---
>  nbd/server.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/nbd/server.c b/nbd/server.c
> index eead339..c29ba5f 100644
> --- a/nbd/server.c
> +++ b/nbd/server.c
> @@ -1080,8 +1080,7 @@ static coroutine_fn void nbd_co_client_start(void *opaque)
>          nbd_export_get(exp);
>      }
>      if (nbd_negotiate(data)) {
> -        shutdown(client->sock, 2);
> -        client->close(client);
> +        client_close(client);
>          goto out;
>      }
>      qemu_co_mutex_init(&client->send_lock);
>