XFS_FEAT_DAX_NEVER
{ XFS_FEAT_DAX_NEVER, ",dax=never" },
mp->m_features &= ~(XFS_FEAT_DAX_ALWAYS | XFS_FEAT_DAX_NEVER);
mp->m_features &= ~XFS_FEAT_DAX_NEVER;
mp->m_features |= XFS_FEAT_DAX_NEVER;