raw_bsd: Convert to byte-based interface
Since the raw format driver is just passing things through, we can
do byte-based read and write if the underlying protocol does
likewise.
There's one tricky part - if we probed the image format, we document
that we restrict operations on the initial sector. It's easiest to
keep this guarantee by enforcing read-modify-write on sub-sector
operations (yes, this partially reverts commit
ad82be2f).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id:
1468624988-423-20-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>