xen/blkback: Don't trust the handle from the frontend.

commit 01c681d4c70d64cb72142a2823f27c4146a02e63 upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index c6decb901e5e16f4ba09ccef7db33675aeecb189..73d8c9276b9b29a98cf6d0a3f22dc33f873869e7 100644 (file)
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -623,7 +623,6 @@ 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;