virtio-blk: Treat read/write beyond end as invalid
The block layer fails such reads and writes just fine. However, they
then get treated like valid operations that fail: the error action
gets executed. Unwanted; reporting the error to the guest is the only
sensible action.
Reject them before passing them to the block layer. This bypasses the
error action and I/O accounting.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>