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Date: Thu, 20 Oct 2011 20:06:24 -0400
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>,
        "hch@infradead.org" <hch@infradead.org>,
        "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
        Dong Yang Li <lidongyang@suse.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [Xen-devel] [PATCH 3/3] xen/blk[front|back]: Enhance discard
 support with secure erasing support.
Message-ID: <20111021000624.GA23358@phenom.dumpdata.com>
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On Mon, Oct 17, 2011 at 02:23:01PM +0100, Jan Beulich wrote:
> >>> On 11.10.11 at 22:57, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> wrote:
> > --- a/drivers/block/xen-blkfront.c
> > +++ b/drivers/block/xen-blkfront.c
> >...
> > @@ -705,7 +711,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
> >  static void blkif_completion(struct blk_shadow *s)
> >  {
> >  	int i;
> 
> This function gets called for all types of requests, and hence must filter
> discard ones now that what would be nr_segments can be non-zero,


Oooh, nice catch.

> e.g.
> 
> 	if (s->req.operation == BLKIF_OP_DISCARD)
> 		return;
> 
> Jan
> 
> > -	for (i = 0; i < s->req.nr_segments; i++)
> > +	for (i = 0; i < s->req.u1.nr_segments; i++)
> >  		gnttab_end_foreign_access(s->req.u.rw.seg[i].gref, 0, 0UL);
> >  }
> >  
>