#include "blk.h"
+static struct bio *blk_bio_discard_split(struct request_queue *q,
+ struct bio *bio,
+ struct bio_set *bs,
+ unsigned *nsegs)
+{
+ unsigned int max_discard_sectors, granularity;
+ int alignment;
+ sector_t tmp;
+ unsigned split_sectors;
+
+ *nsegs = 1;
+
+ /* Zero-sector (unknown) and one-sector granularities are the same. */
+ granularity = max(q->limits.discard_granularity >> 9, 1U);
+
+ max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+ max_discard_sectors -= max_discard_sectors % granularity;
+
+ if (unlikely(!max_discard_sectors)) {
+ /* XXX: warn */
+ return NULL;
+ }
+
+ if (bio_sectors(bio) <= max_discard_sectors)
+ return NULL;
+
+ split_sectors = max_discard_sectors;
+
+ /*
+ * If the next starting sector would be misaligned, stop the discard at
+ * the previous aligned sector.
+ */
+ alignment = (q->limits.discard_alignment >> 9) % granularity;
+
+ tmp = bio->bi_iter.bi_sector + split_sectors - alignment;
+ tmp = sector_div(tmp, granularity);
+
+ if (split_sectors > tmp)
+ split_sectors -= tmp;
+
+ return bio_split(bio, split_sectors, GFP_NOIO, bs);
+}
+
+static struct bio *blk_bio_write_same_split(struct request_queue *q,
+ struct bio *bio,
+ struct bio_set *bs,
+ unsigned *nsegs)
+{
+ *nsegs = 1;
+
+ if (!q->limits.max_write_same_sectors)
+ return NULL;
+
+ if (bio_sectors(bio) <= q->limits.max_write_same_sectors)
+ return NULL;
+
+ return bio_split(bio, q->limits.max_write_same_sectors, GFP_NOIO, bs);
+}
+
+static inline unsigned get_max_io_size(struct request_queue *q,
+ struct bio *bio)
+{
+ unsigned sectors = blk_max_size_offset(q, bio->bi_iter.bi_sector);
+ unsigned mask = queue_logical_block_size(q) - 1;
+
+ /* aligned to logical block size */
+ sectors &= ~(mask >> 9);
+
+ return sectors;
+}
+
+static struct bio *blk_bio_segment_split(struct request_queue *q,
+ struct bio *bio,
+ struct bio_set *bs,
+ unsigned *segs)
+{
+ struct bio_vec bv, bvprv, *bvprvp = NULL;
+ struct bvec_iter iter;
+ unsigned seg_size = 0, nsegs = 0, sectors = 0;
+ unsigned front_seg_size = bio->bi_seg_front_size;
+ bool do_split = true;
+ struct bio *new = NULL;
+ const unsigned max_sectors = get_max_io_size(q, bio);
+
+ bio_for_each_segment(bv, bio, iter) {
+ /*
+ * If the queue doesn't support SG gaps and adding this
+ * offset would create a gap, disallow it.
+ */
+ if (bvprvp && bvec_gap_to_prev(q, bvprvp, bv.bv_offset))
+ goto split;
+
+ if (sectors + (bv.bv_len >> 9) > max_sectors) {
+ /*
+ * Consider this a new segment if we're splitting in
+ * the middle of this vector.
+ */
+ if (nsegs < queue_max_segments(q) &&
+ sectors < max_sectors) {
+ nsegs++;
+ sectors = max_sectors;
+ }
+ if (sectors)
+ goto split;
+ /* Make this single bvec as the 1st segment */
+ }
+
+ if (bvprvp && blk_queue_cluster(q)) {
+ if (seg_size + bv.bv_len > queue_max_segment_size(q))
+ goto new_segment;
+ if (!BIOVEC_PHYS_MERGEABLE(bvprvp, &bv))
+ goto new_segment;
+ if (!BIOVEC_SEG_BOUNDARY(q, bvprvp, &bv))
+ goto new_segment;
+
+ seg_size += bv.bv_len;
+ bvprv = bv;
+ bvprvp = &bvprv;
+ sectors += bv.bv_len >> 9;
+
+ if (nsegs == 1 && seg_size > front_seg_size)
+ front_seg_size = seg_size;
+ continue;
+ }
+new_segment:
+ if (nsegs == queue_max_segments(q))
+ goto split;
+
+ nsegs++;
+ bvprv = bv;
+ bvprvp = &bvprv;
+ seg_size = bv.bv_len;
+ sectors += bv.bv_len >> 9;
+
+ if (nsegs == 1 && seg_size > front_seg_size)
+ front_seg_size = seg_size;
+ }
+
+ do_split = false;
+split:
+ *segs = nsegs;
+
+ if (do_split) {
+ new = bio_split(bio, sectors, GFP_NOIO, bs);
+ if (new)
+ bio = new;
+ }
+
+ bio->bi_seg_front_size = front_seg_size;
+ if (seg_size > bio->bi_seg_back_size)
+ bio->bi_seg_back_size = seg_size;
+
+ return do_split ? new : NULL;
+}
+
+void blk_queue_split(struct request_queue *q, struct bio **bio,
+ struct bio_set *bs)
+{
+ struct bio *split, *res;
+ unsigned nsegs;
+
+ if ((*bio)->bi_rw & REQ_DISCARD)
+ split = blk_bio_discard_split(q, *bio, bs, &nsegs);
+ else if ((*bio)->bi_rw & REQ_WRITE_SAME)
+ split = blk_bio_write_same_split(q, *bio, bs, &nsegs);
+ else
+ split = blk_bio_segment_split(q, *bio, q->bio_split, &nsegs);
+
+ /* physical segments can be figured out during splitting */
+ res = split ? split : *bio;
+ res->bi_phys_segments = nsegs;
+ bio_set_flag(res, BIO_SEG_VALID);
+
+ if (split) {
+ /* there isn't chance to merge the splitted bio */
+ split->bi_rw |= REQ_NOMERGE;
+
+ bio_chain(split, *bio);
+ generic_make_request(*bio);
+ *bio = split;
+ }
+}
+EXPORT_SYMBOL(blk_queue_split);
+
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;
+ int cluster, prev = 0;
unsigned int seg_size, nr_phys_segs;
struct bio *fbio, *bbio;
struct bvec_iter iter;
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 (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 (prev && cluster) {
if (seg_size + bv.bv_len
> queue_max_segment_size(q))
goto new_segment;
nr_phys_segs++;
bvprv = bv;
+ prev = 1;
seg_size = bv.bv_len;
- highprv = high;
}
bbio = bio;
}
bio->bi_next = nxt;
}
- bio->bi_flags |= (1 << BIO_SEG_VALID);
+ bio_set_flag(bio, BIO_SEG_VALID);
}
EXPORT_SYMBOL(blk_recount_segments);
if (rq->cmd_flags & REQ_WRITE)
memset(q->dma_drain_buffer, 0, q->dma_drain_size);
- sg->page_link &= ~0x02;
+ sg_unmark_end(sg);
sg = sg_next(sg);
sg_set_page(sg, virt_to_page(q->dma_drain_buffer),
q->dma_drain_size,
if (sg)
sg_mark_end(sg);
+ /*
+ * Something must have been wrong if the figured number of
+ * segment is bigger than number of req's physical segments
+ */
+ WARN_ON(nsegs > rq->nr_phys_segments);
+
return nsegs;
}
EXPORT_SYMBOL(blk_rq_map_sg);
int ll_back_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio)
{
+ if (req_gap_back_merge(req, bio))
+ return 0;
+ if (blk_integrity_rq(req) &&
+ integrity_req_gap_back_merge(req, bio))
+ return 0;
if (blk_rq_sectors(req) + bio_sectors(bio) >
blk_rq_get_max_sectors(req)) {
req->cmd_flags |= REQ_NOMERGE;
int ll_front_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio)
{
+
+ if (req_gap_front_merge(req, bio))
+ return 0;
+ if (blk_integrity_rq(req) &&
+ integrity_req_gap_front_merge(req, bio))
+ return 0;
if (blk_rq_sectors(req) + bio_sectors(bio) >
blk_rq_get_max_sectors(req)) {
req->cmd_flags |= REQ_NOMERGE;
return !q->mq_ops && req->special;
}
-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);
-}
-
static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
struct request *next)
{
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))
+ if (req_gap_back_merge(req, next->bio))
return 0;
/*
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;
!blk_write_same_mergeable(rq->bio, bio))
return false;
- if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS)) {
- 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;
}
Code Review / kvmfornfv.git / blobdiff