From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751408AbaEYVyJ (ORCPT ); Sun, 25 May 2014 17:54:09 -0400 Received: from mail-we0-f175.google.com ([74.125.82.175]:47420 "EHLO mail-we0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751191AbaEYVyH (ORCPT ); Sun, 25 May 2014 17:54:07 -0400 Date: Sun, 25 May 2014 22:54:02 +0100 From: Hani Benhabiles To: Paul Clements Cc: "nbd-general@lists.sourceforge.net" , kernel list Subject: Re: [PATCH] nbd: Zero from and len fields in NBD_CMD_DISCONNECT. Message-ID: <20140525215402.GE3588@Inspiron-3521> References: <1400283807-27930-1-git-send-email-kroosec@gmail.com> <20140518091113.GA3770@Inspiron-3521> <20140525101840.GA3588@Inspiron-3521> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 25, 2014 at 02:11:13PM -0400, Paul Clements wrote: > On Sun, May 25, 2014 at 6:18 AM, Hani Benhabiles wrote: > > On Sun, May 18, 2014 at 10:11:13AM +0100, Hani Benhabiles wrote: > >> On Fri, May 16, 2014 at 10:56:33PM -0400, Paul Clements wrote: > >> > Agreed. But better yet, the request structure should just be zeroed when > >> > it's allocated. > >> > > >> > >> It is already initialized in __nbd_ioctl() with the blk_rq_init() call which > >> sets the __sector value to -1 (which is 0xfffffffffffffe00 after the left shifts.) > >> > >> This is the only (non-ugly / non-intrusive) way to do it afaict. > >> > > > > Ping! > > > > Anything blocking this patch ? > > It's cleaner to just zero the struct and get rid of the conditional > zeroing of specific fields. I'll prepare a patch in the next few days. > Sorry, I misunderstood which struct you were talking about! Will send a v2 shortly. > Thanks, > Paul > > >> > On Fri, May 16, 2014 at 7:43 PM, Hani Benhabiles wrote: > >> > > >> > > Len field is already set to zero, but not the from field which is sent as > >> > > 0xfffffffffffffe00. This makes no sense, and may cause confuse server > >> > > implementations doing sanity checks (qemu-nbd is an example.) > >> > > > >> > > Signed-off-by: Hani Benhabiles > >> > > --- > >> > > drivers/block/nbd.c | 2 +- > >> > > 1 file changed, 1 insertion(+), 1 deletion(-) > >> > > > >> > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > >> > > index 3a70ea2..657bdac 100644 > >> > > --- a/drivers/block/nbd.c > >> > > +++ b/drivers/block/nbd.c > >> > > @@ -246,7 +246,7 @@ static int nbd_send_req(struct nbd_device *nbd, struct > >> > > request *req) > >> > > request.magic = htonl(NBD_REQUEST_MAGIC); > >> > > request.type = htonl(nbd_cmd(req)); > >> > > > >> > > - if (nbd_cmd(req) == NBD_CMD_FLUSH) { > >> > > + if (nbd_cmd(req) == NBD_CMD_FLUSH || nbd_cmd(req) == NBD_CMD_DISC) > >> > > { > >> > > /* Other values are reserved for FLUSH requests. */ > >> > > request.from = 0; > >> > > request.len = 0; > >> > > -- > >> > > 1.8.3.2 > >> > > > >> > >