> @@ -328,6 +328,29 @@ int bio_split_io_at(struct bio *bio, const struct
> queue_limits *lim,
> unsigned nsegs = 0, bytes = 0, gaps = 0;
> struct bvec_iter iter;
>
> + if (bio_flagged(bio, BIO_DMA_TOKEN)) {
> + int offset = offset_in_page(bio->bi_iter.bi_bvec_done);
> +
> + nsegs = ALIGN(bio->bi_iter.bi_size + offset, PAGE_SIZE);
> + nsegs >>= PAGE_SHIFT;
> +
> + if (offset & lim->dma_alignment || bytes & len_align_mask)
> + return -EINVAL;
bytes == 0 is a dead check here. Probably you would like to check the
length of the first and last segment to match with what the normal path
below is doing.
