static inline int ll_new_hw_segment(struct request_queue *q,
struct request *req,
struct bio *bio)
{
int nr_phys_segs = bio_phys_segments(q, bio);
if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q))
goto no_merge;
if (blk_integrity_merge_bio(q, req, bio) == false)
goto no_merge;
/*
* This will form the start of a new hw segment. Bump both
* counters.
*/
req->nr_phys_segments += nr_phys_segs;
return 1;
no_merge:
req->cmd_flags |= REQ_NOMERGE;
if (req == q->last_merge)
q->last_merge = NULL;
return 0;
}
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
bio->bi_vcnt < queue_max_segments(q))
bio->bi_phys_segments = bio->bi_vcnt;
else {
struct bio *nxt = bio->bi_next;
bio->bi_next = NULL;
bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false);
bio->bi_next = nxt;
}
bio->bi_flags |= (1 << BIO_SEG_VALID);
}
static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
struct request *next)
{
int total_phys_segments;
unsigned int seg_size =
req->biotail->bi_seg_back_size + next->bio->bi_seg_front_size;
/*
* First check if the either of the requests are re-queued
* requests. Can't merge them if they are.
*/
if (req_no_special_merge(req) || req_no_special_merge(next))
return 0;
if (test_bit(QUEUE_FLAG_SG_GAPS, &q->queue_flags) &&
req_gap_to_prev(req, next))
return 0;
/*
* Will it become too large?
*/
if ((blk_rq_sectors(req) + blk_rq_sectors(next)) >
blk_rq_get_max_sectors(req))
return 0;
total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
if (blk_phys_contig_segment(q, req->biotail, next->bio)) {
if (req->nr_phys_segments == 1)
req->bio->bi_seg_front_size = seg_size;
if (next->nr_phys_segments == 1)
next->biotail->bi_seg_back_size = seg_size;
total_phys_segments--;
}
if (total_phys_segments > queue_max_segments(q))
return 0;
if (blk_integrity_merge_rq(q, req, next) == false)
return 0;
/* Merge is OK... */
req->nr_phys_segments = total_phys_segments;
return 1;
}
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
bool no_sg_merge = !!test_bit(QUEUE_FLAG_NO_SG_MERGE,
&q->queue_flags);
if (no_sg_merge && !bio_flagged(bio, BIO_CLONED) &&
bio->bi_vcnt < queue_max_segments(q))
bio->bi_phys_segments = bio->bi_vcnt;
else {
struct bio *nxt = bio->bi_next;
bio->bi_next = NULL;
bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio,
no_sg_merge);
bio->bi_next = nxt;
}
bio->bi_flags |= (1 << BIO_SEG_VALID);
}
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
unsigned short seg_cnt;
/* estimate segment number by bi_vcnt for non-cloned bio */
if (bio_flagged(bio, BIO_CLONED))
seg_cnt = bio_segments(bio);
else
seg_cnt = bio->bi_vcnt;
if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
(seg_cnt < queue_max_segments(q)))
bio->bi_phys_segments = seg_cnt;
else {
struct bio *nxt = bio->bi_next;
bio->bi_next = NULL;
bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false);
bio->bi_next = nxt;
}
bio->bi_flags |= (1 << BIO_SEG_VALID);
}
static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
{
return queue_var_show(queue_max_segments(q), (page));
}
