MTD_UBIVOLUME
if (mtd->type == MTD_ABSENT || mtd->type == MTD_UBIVOLUME)
if (mtd->type != MTD_ABSENT && mtd->type != MTD_UBIVOLUME)
case MTD_UBIVOLUME:
if (mtd->type == MTD_UBIVOLUME) {
mtd->type = MTD_UBIVOLUME;
#define jffs2_ubivol(c) (c->mtd->type == MTD_UBIVOLUME)