Messages in this thread | | | Date | Mon, 28 Jan 2013 11:09:15 +0000 | From | "Jan Beulich" <> | Subject | Re: [Xen-devel] [PATCH 1/3] xen/blkback: Don't trust the handle from the frontend. |
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>>> On 25.01.13 at 18:32, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> wrote: > The 'handle' is the device that the request is from. For the life-time > of the ring we copy it from a request to a response so that the frontend > is not surprised by it. But we do not need it - when we start processing > I/Os we have our own 'struct phys_req' which has only most essential > information about the request. In fact the 'vbd_translate' ends up > over-writing the preq.dev with a value from the backend. > > This assignment of preq.dev with the 'handle' value is superfluous > so lets not do it. > > Cc: stable@vger.kernel.org
Is this really stable material? It fixes nothing but the (wrong) impression that the driver might be using frontend provided data without checking.
Jan
> Acked-by: Jan Beulich <jbeulich@suse.com> > Acked-by: Ian Campbell <ian.campbell@citrix.com> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > drivers/block/xen-blkback/blkback.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/block/xen-blkback/blkback.c > b/drivers/block/xen-blkback/blkback.c > index 742871d..2de3da9 100644 > --- a/drivers/block/xen-blkback/blkback.c > +++ b/drivers/block/xen-blkback/blkback.c > @@ -890,7 +890,6 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, > goto fail_response; > } > > - preq.dev = req->u.rw.handle; > preq.sector_number = req->u.rw.sector_number; > preq.nr_sects = 0; > > -- > 1.8.0.2 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel
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