These will freeze and thaw filesystems within guest specified by
@mountpoints parameters. The parameters can be NULL and 0, then all
mounted filesystems are frozen or thawed. @flags parameter, which are
currently not used, is for future extensions.
Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama@hds.com>
Signed-off-by: NEric Blake <eblake@redhat.com>