-/* We want read requests to align with chunks where possible,
- * but write requests don't need to.
- */
-static int raid5_mergeable_bvec(struct mddev *mddev,
- struct bvec_merge_data *bvm,
- struct bio_vec *biovec)
-{
- sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
- int max;
- unsigned int chunk_sectors = mddev->chunk_sectors;
- unsigned int bio_sectors = bvm->bi_size >> 9;
-
- /*
- * always allow writes to be mergeable, read as well if array
- * is degraded as we'll go through stripe cache anyway.
- */
- if ((bvm->bi_rw & 1) == WRITE || mddev->degraded)
- return biovec->bv_len;
-
- if (mddev->new_chunk_sectors < mddev->chunk_sectors)
- chunk_sectors = mddev->new_chunk_sectors;
- max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
- if (max < 0) max = 0;
- if (max <= biovec->bv_len && bio_sectors == 0)
- return biovec->bv_len;
- else
- return max;
-}
-