DP_DISCARD
(bio_op(bio) == REQ_OP_DISCARD ? DP_DISCARD : 0) |
(DP_ZEROES |(!(bio->bi_opf & REQ_NOUNMAP) ? DP_DISCARD : 0))
: DP_DISCARD)
if (dp_flags & (DP_DISCARD|DP_ZEROES)) {
if (dpf & DP_DISCARD)
if (dp_flags & DP_DISCARD)