From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [GIT PULL] for-2.6.32/bug-fixes Date: Tue, 17 May 2011 11:57:46 -0400 Message-ID: <20110517155746.GB3657@dumpdata.com> References: <20110516203535.GA871@dumpdata.com> <4DD260700200007800041962@vpn.id2.novell.com> <20110517141629.GC6816@dumpdata.com> <4DD2AAF80200007800041AC9@vpn.id2.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4DD2AAF80200007800041AC9@vpn.id2.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich Cc: Jeremy Fitzhardinge , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org > > No attaching of data to the barrier. > > Sure, this direction we agree about. But your change is enforcing > it the other way around (if barrier then no data), which wasn't the > case so far. OK, even if the code that actually does the bio submission does not attach any data to the bio? The end result is the same - no data with barriers. > > >> Hence shouldn't you clear the sector number only when > >> req->nr_segments is zero? Or alternatively, shouldn't > > > > We could do that too. > > > >> vbd_translate() simply not fail when req->nr_sects is zero? > > > > It does not fail when req->nr_sects is zero. It fails when it is -1. > > > >> > >> Additionally, looking at the check in vbd_translate(), wouldn't you > >> think there ought to be overflow checking for the addition, too? > > > > Sure, could add that in. Albeit it seems incorrect to do it in that > > function. It checks to see if the sector is correct, and -1 is definitly > > wrong. > > Hmm, depends on your perspective - I'd say that any sector_number > is valid when nr_sects is zero. I concur. The value that is passed by the frontend is not zero. It is -1.