static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
struct bio *nxt)
{
if (!blk_queue_cluster(q))
return 0;
if (bio->bi_seg_back_size + nxt->bi_seg_front_size >
queue_max_segment_size(q))
return 0;
if (!bio_has_data(bio))
return 1;
if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)))
return 0;
/*
* bio and nxt are contiguous in memory; check if the queue allows
* these two to be merged into one
*/
if (BIO_SEG_BOUNDARY(q, bio, nxt))
return 1;
return 0;
}
static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
{
if (blk_queue_cluster(q))
return queue_var_show(queue_max_segment_size(q), (page));
return queue_var_show(PAGE_CACHE_SIZE, (page));
}
static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
struct bio *nxt)
{
struct bio_vec end_bv = { NULL }, nxt_bv;
struct bvec_iter iter;
if (!blk_queue_cluster(q))
return 0;
if (bio->bi_seg_back_size + nxt->bi_seg_front_size >
queue_max_segment_size(q))
return 0;
if (!bio_has_data(bio))
return 1;
bio_for_each_segment(end_bv, bio, iter)
if (end_bv.bv_len == iter.bi_size)
break;
nxt_bv = bio_iovec(nxt);
if (!BIOVEC_PHYS_MERGEABLE(&end_bv, &nxt_bv))
return 0;
/*
* bio and nxt are contiguous in memory; check if the queue allows
* these two to be merged into one
*/
if (BIOVEC_SEG_BOUNDARY(q, &end_bv, &nxt_bv))
return 1;
return 0;
}
static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
struct bio *bio)
{
struct bio_vec *bv, *bvprv = NULL;
int cluster, i, high, highprv = 1;
unsigned int seg_size, nr_phys_segs;
struct bio *fbio, *bbio;
if (!bio)
return 0;
fbio = bio;
cluster = blk_queue_cluster(q);
seg_size = 0;
nr_phys_segs = 0;
for_each_bio(bio) {
bio_for_each_segment(bv, bio, i) {
/*
*/
high = page_to_pfn(bv->bv_page) > queue_bounce_pfn(q);
if (high || highprv)
goto new_segment;
if (cluster) {
if (seg_size + bv->bv_len
> queue_max_segment_size(q))
goto new_segment;
if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
goto new_segment;
if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
goto new_segment;
if ((bvprv->bv_page != bv->bv_page) &&
(bvprv->bv_page + 1) != bv->bv_page)
goto new_segment;
seg_size += bv->bv_len;
bvprv = bv;
continue;
}
new_segment:
if (nr_phys_segs == 1 && seg_size >
fbio->bi_seg_front_size)
fbio->bi_seg_front_size = seg_size;
nr_phys_segs++;
bvprv = bv;
seg_size = bv->bv_len;
highprv = high;
}
bbio = bio;
}
static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
struct bio *bio)
{
unsigned int phys_size;
struct bio_vec *bv, *bvprv = NULL;
int cluster, i, high, highprv = 1;
unsigned int seg_size, nr_phys_segs;
struct bio *fbio, *bbio;
if (!bio)
return 0;
fbio = bio;
cluster = blk_queue_cluster(q);
seg_size = 0;
phys_size = nr_phys_segs = 0;
for_each_bio(bio) {
bio_for_each_segment(bv, bio, i) {
/*
* the trick here is making sure that a high page is
* never considered part of another segment, since that
* might change with the bounce page.
*/
high = page_to_pfn(bv->bv_page) > queue_bounce_pfn(q);
if (high || highprv)
goto new_segment;
if (cluster) {
if (seg_size + bv->bv_len
> queue_max_segment_size(q))
goto new_segment;
if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
goto new_segment;
if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
goto new_segment;
seg_size += bv->bv_len;
bvprv = bv;
continue;
}
new_segment:
if (nr_phys_segs == 1 && seg_size >
fbio->bi_seg_front_size)
fbio->bi_seg_front_size = seg_size;
nr_phys_segs++;
bvprv = bv;
seg_size = bv->bv_len;
highprv = high;
}
bbio = bio;
}
static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
struct bio *bio)
{
struct bio_vec *bv, *bvprv = NULL;
int cluster, i, high, highprv = 1;
unsigned int seg_size, nr_phys_segs;
struct bio *fbio, *bbio;
if (!bio)
return 0;
fbio = bio;
cluster = blk_queue_cluster(q);
seg_size = 0;
nr_phys_segs = 0;
for_each_bio(bio) {
bio_for_each_segment(bv, bio, i) {
/*
* the trick here is making sure that a high page is
* never considered part of another segment, since that
* might change with the bounce page.
*/
high = page_to_pfn(bv->bv_page) > queue_bounce_pfn(q);
if (high || highprv)
goto new_segment;
if (cluster) {
if (seg_size + bv->bv_len
> queue_max_segment_size(q))
goto new_segment;
if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
goto new_segment;
if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
goto new_segment;
<<<<<<< HEAD
if ((bvprv->bv_page != bv->bv_page) &&
(bvprv->bv_page + 1) != bv->bv_page)
goto new_segment;
=======
<<<<<<< HEAD
if ((bvprv->bv_page != bv->bv_page) &&
(bvprv->bv_page + 1) != bv->bv_page)
goto new_segment;
=======
>>>>>>> 58a75b6a81be54a8b491263ca1af243e9d8617b9
>>>>>>> ae1773bb70f3d7cf73324ce8fba787e01d8fa9f2
/*
* map a request to scatterlist, return number of sg entries setup. Caller
* must make sure sg can hold rq->nr_phys_segments entries
*/
int blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sglist)
{
struct bio_vec *bvec, *bvprv;
struct req_iterator iter;
struct scatterlist *sg;
int nsegs, cluster;
nsegs = 0;
cluster = blk_queue_cluster(q);
/*
* for each bio in rq
*/
bvprv = NULL;
sg = NULL;
rq_for_each_segment(bvec, rq, iter) {
__blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg,
&nsegs, &cluster);
} /* segments in rq */
static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio,
struct scatterlist *sglist,
struct scatterlist **sg)
{
struct bio_vec bvec, bvprv = { NULL };
struct bvec_iter iter;
int nsegs, cluster;
nsegs = 0;
cluster = blk_queue_cluster(q);
if (bio->bi_rw & REQ_DISCARD) {
/*
* This is a hack - drivers should be neither modifying the
* biovec, nor relying on bi_vcnt - but because of
* blk_add_request_payload(), a discard bio may or may not have
* a payload we need to set up here (thank you Christoph) and
* bi_vcnt is really the only way of telling if we need to.
*/
if (bio->bi_vcnt)
goto single_segment;
return 0;
}
if (bio->bi_rw & REQ_WRITE_SAME) {
single_segment:
*sg = sglist;
bvec = bio_iovec(bio);
sg_set_page(*sg, bvec.bv_page, bvec.bv_len, bvec.bv_offset);
return 1;
}
for_each_bio(bio)
bio_for_each_segment(bvec, bio, iter)
__blk_segment_map_sg(q, &bvec, sglist, &bvprv, sg,
&nsegs, &cluster);
return nsegs;
}
static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
struct bio *bio,
bool no_sg_merge)
{
struct bio_vec bv, bvprv = { NULL };
int cluster, high, highprv = 1;
unsigned int seg_size, nr_phys_segs;
struct bio *fbio, *bbio;
struct bvec_iter iter;
if (!bio)
return 0;
/*
* This should probably be returning 0, but blk_add_request_payload()
* (Christoph!!!!)
*/
if (bio->bi_rw & REQ_DISCARD)
return 1;
if (bio->bi_rw & REQ_WRITE_SAME)
return 1;
fbio = bio;
cluster = blk_queue_cluster(q);
seg_size = 0;
nr_phys_segs = 0;
high = 0;
for_each_bio(bio) {
bio_for_each_segment(bv, bio, iter) {
/*
* If SG merging is disabled, each bio vector is
* a segment
*/
if (no_sg_merge)
goto new_segment;
/*
* the trick here is making sure that a high page is
* never considered part of another segment, since
* that might change with the bounce page.
*/
high = page_to_pfn(bv.bv_page) > queue_bounce_pfn(q);
if (!high && !highprv && cluster) {
if (seg_size + bv.bv_len
> queue_max_segment_size(q))
goto new_segment;
if (!BIOVEC_PHYS_MERGEABLE(&bvprv, &bv))
goto new_segment;
if (!BIOVEC_SEG_BOUNDARY(q, &bvprv, &bv))
goto new_segment;
seg_size += bv.bv_len;
bvprv = bv;
continue;
}
new_segment:
if (nr_phys_segs == 1 && seg_size >
fbio->bi_seg_front_size)
fbio->bi_seg_front_size = seg_size;
nr_phys_segs++;
bvprv = bv;
seg_size = bv.bv_len;
highprv = high;
}
bbio = bio;
}
if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size)
fbio->bi_seg_front_size = seg_size;
if (seg_size > bbio->bi_seg_back_size)
bbio->bi_seg_back_size = seg_size;
return nr_phys_segs;
}