static int req_gap_to_prev(struct request *req, struct request *next)
{
struct bio *prev = req->biotail;
return bvec_gap_to_prev(&prev->bi_io_vec[prev->bi_vcnt - 1],
next->bio->bi_io_vec[0].bv_offset);
}
/**
* bio_integrity_add_page - Attach integrity metadata
* @bio: bio to update
* @page: page containing integrity metadata
* @len: number of bytes of integrity metadata in page
* @offset: start offset within page
*
* Description: Attach a page containing integrity metadata to bio.
*/
int bio_integrity_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct bio_vec *iv;
if (bip->bip_vcnt >= bip->bip_max_vcnt) {
printk(KERN_ERR "%s: bip_vec full\n", __func__);
return 0;
}
iv = bip->bip_vec + bip->bip_vcnt;
if (bip->bip_vcnt &&
bvec_gap_to_prev(bdev_get_queue(bio->bi_bdev),
&bip->bip_vec[bip->bip_vcnt - 1], offset))
return 0;
iv->bv_page = page;
iv->bv_len = len;
iv->bv_offset = offset;
bip->bip_vcnt++;
return len;
}
bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
{
struct request_queue *q = rq->q;
if (!rq_mergeable(rq) || !bio_mergeable(bio))
return false;
if (!blk_check_merge_flags(rq->cmd_flags, bio->bi_rw))
return false;
/* different data direction or already started, don't merge */
if (bio_data_dir(bio) != rq_data_dir(rq))
return false;
/* must be same device and not a special request */
if (rq->rq_disk != bio->bi_bdev->bd_disk || req_no_special_merge(rq))
return false;
/* only merge integrity protected bio into ditto rq */
if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
return false;
/* must be using the same buffer */
if (rq->cmd_flags & REQ_WRITE_SAME &&
!blk_write_same_mergeable(rq->bio, bio))
return false;
/* Only check gaps if the bio carries data */
if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && bio_has_data(bio)) {
struct bio_vec *bprev;
bprev = &rq->biotail->bi_io_vec[rq->biotail->bi_vcnt - 1];
if (bvec_gap_to_prev(bprev, bio->bi_io_vec[0].bv_offset))
return false;
}
return true;
}