The sparsify function can be used to make an image sparse by replacing
runs of zeros with holes. This change adds a wrapper for the basic
rbd_sparsify function and accompanying tests.
Signed-off-by: John Mulligan <jmulligan@redhat.com>
In order to avoid external dependencies on implementation details,
this change replaces RBDError with the unexported rbdError. In case
some application really needs access to the integer value, it can use
the pattern
var errno interface{ Errno() int }
if errors.As(err, errno) { ... errno.Errno() ... }
Signed-off-by: Sven Anderson <sven@redhat.com>