--- a/usr/src/lib/libzfs/common/libzfs.h	Thu Jan 07 21:27:35 2010 +0100
+++ b/usr/src/lib/libzfs/common/libzfs.h	Thu Jan 07 13:33:12 2010 -0700
@@ -529,6 +529,7 @@
 extern int zfs_release(zfs_handle_t *, const char *, const char *, boolean_t);
 extern int zfs_release_range(zfs_handle_t *, const char *, const char *,
     const char *);
+extern uint64_t zvol_volsize_to_reservation(uint64_t, nvlist_t *);
 
 typedef int (*zfs_userspace_cb_t)(void *arg, const char *domain,
     uid_t rid, uint64_t space);