From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH 2/6] xen-blkfront: handle backend CLOSED without CLOSING Date: Tue, 9 Oct 2012 12:30:23 -0400 Message-ID: <20121009163023.GG31499@phenom.dumpdata.com> References: <1348243464-15903-1-git-send-email-david.vrabel@citrix.com> <1348243464-15903-3-git-send-email-david.vrabel@citrix.com> <5061EFB2.1080407@citrix.com> <5069D097.60606@citrix.com> <20121002200255.GA668@phenom.dumpdata.com> <506EC79D.5080206@citrix.com> <506EE6CD020000780009FF4E@nat28.tlf.novell.com> <506F0370.6050905@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <506F0370.6050905@citrix.com> Sender: linux-kernel-owner@vger.kernel.org To: David Vrabel Cc: Jan Beulich , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" List-Id: xen-devel@lists.xenproject.org On Fri, Oct 05, 2012 at 04:57:36PM +0100, David Vrabel wrote: > On 05/10/12 12:55, Jan Beulich wrote: > >>>> On 05.10.12 at 13:42, David Vrabel wrote: > >> On 02/10/12 21:02, Konrad Rzeszutek Wilk wrote: > >>> On Mon, Oct 01, 2012 at 06:19:19PM +0100, David Vrabel wrote: > >>>> On 25/09/12 18:53, David Vrabel wrote: > >>>>> On 21/09/12 17:04, David Vrabel wrote: > >>>>>> From: David Vrabel > >>>>>> > >>>>>> Backend drivers shouldn't transistion to CLOSED unless the frontend is > >>>>>> CLOSED. If a backend does transition to CLOSED too soon then the > >>>>>> frontend may not see the CLOSING state and will not properly shutdown. > >>>>>> > >>>>>> So, treat an unexpected backend CLOSED state the same as CLOSING. > >>>>> > >>>>> Didn't handle the frontend block device being mounted. Updated patch here. > >>>> > >>>> Konrad, can you ack this updated patch if you're happy with it. > >>> > >>> Acked-by: Konrad Rzeszutek Wilk > >>> > >>> Or should I just carry it in my for-jens-3.7 bug-fixes queue and ask > >>> Jen to pull it once rc0 is out? > >> > >> This seems easiest, if Jan is happy with the patch. > > > > I see the point of your explanation yesterday, but am still not > > convinced that the early cleanup in spite of active users of the > > disk can't cause any problems (like dangling pointers or NULL > > dereferences). > > I tested it some more and it is broken. Please apply the first version > instead. OK, can we do this once more - can you repost the patches, but CC the invidiual maintainers? The FB and KBD need to go through Florian I think? > > blkfront needs to cancel and complete with an error requests that are > are still on the ring after the backend has disconnected and it needs to > complete with an error all requests submitted while disconnected. > Otherwise, if there is outstanding requests or new requests then > del_gendisk() blocks waiting for the I/O to complete. > > David