blk_flush
msg->any.blk_flush.keyid = sc->keyid;
msg->any.blk_flush.offset = bio->bio_offset;
msg->any.blk_flush.bytes = bp->b_bcount;
bp->b_bcount = msg->any.blk_flush.bytes;
bio->bio_offset = msg->any.blk_flush.offset;
error = blk_flush(di);
error = blk_flush(di);
error = blk_flush(di);
error = blk_flush(di);
dmsg_blk_flush_t blk_flush;