xen-blkfront: restore the non-persistent data path
authorRoger Pau Monne <roger.pau@citrix.com>
Tue, 29 Oct 2013 17:31:14 +0000 (18:31 +0100)
committerJens Axboe <axboe@kernel.dk>
Fri, 8 Nov 2013 16:10:30 +0000 (09:10 -0700)
commitbfe11d6de1c416cea4f3f0f35f864162063ce3fa
tree25bc44562e7794cc41327c7c447cd49a9935a876
parentf1a3c6191369632ada5b709997b91a7f15045ff4
xen-blkfront: restore the non-persistent data path

When persistent grants were added they were always used, even if the
backend doesn't have this feature (there's no harm in always using the
same set of pages). This restores the old data path when the backend
doesn't have persistent grants, removing the burden of doing a memcpy
when it is not actually needed.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-by: Felipe Franciosi <felipe.franciosi@citrix.com>
Cc: Felipe Franciosi <felipe.franciosi@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Fix up whitespace issues]
drivers/block/xen-blkfront.c