UFS_NEEDSWAP
ump->um_flags |= UFS_NEEDSWAP;
if (mp->um_flags & UFS_NEEDSWAP)
if (mp->um_flags & UFS_NEEDSWAP)
if (ump->um_flags & UFS_NEEDSWAP) {
#define UFS_MPNEEDSWAP(ump) ((ump)->um_flags & UFS_NEEDSWAP)