-}
-
-/* This is called by bio_add_page().
- *
- * q->max_hw_sectors and other global limits are already enforced there.
- *
- * We need to call down to our lower level device,
- * in case it has special restrictions.
- *
- * We also may need to enforce configured max-bio-bvecs limits.
- *
- * As long as the BIO is empty we have to allow at least one bvec,
- * regardless of size and offset, so no need to ask lower levels.
- */
-int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec)
-{
- struct drbd_device *device = (struct drbd_device *) q->queuedata;
- unsigned int bio_size = bvm->bi_size;
- int limit = DRBD_MAX_BIO_SIZE;
- int backing_limit;
-
- if (bio_size && get_ldev(device)) {
- unsigned int max_hw_sectors = queue_max_hw_sectors(q);
- struct request_queue * const b =
- device->ldev->backing_bdev->bd_disk->queue;
- if (b->merge_bvec_fn) {
- bvm->bi_bdev = device->ldev->backing_bdev;
- backing_limit = b->merge_bvec_fn(b, bvm, bvec);
- limit = min(limit, backing_limit);
- }
- put_ldev(device);
- if ((limit >> 9) > max_hw_sectors)
- limit = max_hw_sectors << 9;
- }
- return limit;