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-rw-r--r--block/blk-merge.c129
1 files changed, 25 insertions, 104 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 5efc9e7a68b7..908d3e11ac52 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -11,7 +11,7 @@
void blk_recalc_rq_sectors(struct request *rq, int nsect)
{
- if (blk_fs_request(rq)) {
+ if (blk_fs_request(rq) || blk_discard_rq(rq)) {
rq->hard_sector += nsect;
rq->hard_nr_sectors -= nsect;
@@ -41,12 +41,9 @@ void blk_recalc_rq_sectors(struct request *rq, int nsect)
void blk_recalc_rq_segments(struct request *rq)
{
int nr_phys_segs;
- int nr_hw_segs;
unsigned int phys_size;
- unsigned int hw_size;
struct bio_vec *bv, *bvprv = NULL;
int seg_size;
- int hw_seg_size;
int cluster;
struct req_iterator iter;
int high, highprv = 1;
@@ -56,8 +53,8 @@ void blk_recalc_rq_segments(struct request *rq)
return;
cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
- hw_seg_size = seg_size = 0;
- phys_size = hw_size = nr_phys_segs = nr_hw_segs = 0;
+ seg_size = 0;
+ phys_size = nr_phys_segs = 0;
rq_for_each_segment(bv, rq, iter) {
/*
* the trick here is making sure that a high page is never
@@ -66,7 +63,7 @@ void blk_recalc_rq_segments(struct request *rq)
*/
high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
if (high || highprv)
- goto new_hw_segment;
+ goto new_segment;
if (cluster) {
if (seg_size + bv->bv_len > q->max_segment_size)
goto new_segment;
@@ -74,40 +71,19 @@ void blk_recalc_rq_segments(struct request *rq)
goto new_segment;
if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
goto new_segment;
- if (BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))
- goto new_hw_segment;
seg_size += bv->bv_len;
- hw_seg_size += bv->bv_len;
bvprv = bv;
continue;
}
new_segment:
- if (BIOVEC_VIRT_MERGEABLE(bvprv, bv) &&
- !BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))
- hw_seg_size += bv->bv_len;
- else {
-new_hw_segment:
- if (nr_hw_segs == 1 &&
- hw_seg_size > rq->bio->bi_hw_front_size)
- rq->bio->bi_hw_front_size = hw_seg_size;
- hw_seg_size = BIOVEC_VIRT_START_SIZE(bv) + bv->bv_len;
- nr_hw_segs++;
- }
-
nr_phys_segs++;
bvprv = bv;
seg_size = bv->bv_len;
highprv = high;
}
- if (nr_hw_segs == 1 &&
- hw_seg_size > rq->bio->bi_hw_front_size)
- rq->bio->bi_hw_front_size = hw_seg_size;
- if (hw_seg_size > rq->biotail->bi_hw_back_size)
- rq->biotail->bi_hw_back_size = hw_seg_size;
rq->nr_phys_segments = nr_phys_segs;
- rq->nr_hw_segments = nr_hw_segs;
}
void blk_recount_segments(struct request_queue *q, struct bio *bio)
@@ -120,7 +96,6 @@ void blk_recount_segments(struct request_queue *q, struct bio *bio)
blk_recalc_rq_segments(&rq);
bio->bi_next = nxt;
bio->bi_phys_segments = rq.nr_phys_segments;
- bio->bi_hw_segments = rq.nr_hw_segments;
bio->bi_flags |= (1 << BIO_SEG_VALID);
}
EXPORT_SYMBOL(blk_recount_segments);
@@ -131,13 +106,17 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
if (!test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
return 0;
- if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)))
- return 0;
if (bio->bi_size + nxt->bi_size > q->max_segment_size)
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 contigous in memory, check if the queue allows
+ * 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))
@@ -146,22 +125,6 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
return 0;
}
-static int blk_hw_contig_segment(struct request_queue *q, struct bio *bio,
- struct bio *nxt)
-{
- if (!bio_flagged(bio, BIO_SEG_VALID))
- blk_recount_segments(q, bio);
- if (!bio_flagged(nxt, BIO_SEG_VALID))
- blk_recount_segments(q, nxt);
- if (!BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)) ||
- BIOVEC_VIRT_OVERSIZE(bio->bi_hw_back_size + nxt->bi_hw_front_size))
- return 0;
- if (bio->bi_hw_back_size + nxt->bi_hw_front_size > q->max_segment_size)
- return 0;
-
- return 1;
-}
-
/*
* map a request to scatterlist, return number of sg entries setup. Caller
* must make sure sg can hold rq->nr_phys_segments entries
@@ -275,10 +238,9 @@ static inline int ll_new_hw_segment(struct request_queue *q,
struct request *req,
struct bio *bio)
{
- int nr_hw_segs = bio_hw_segments(q, bio);
int nr_phys_segs = bio_phys_segments(q, bio);
- if (req->nr_hw_segments + nr_hw_segs > q->max_hw_segments
+ if (req->nr_phys_segments + nr_phys_segs > q->max_hw_segments
|| req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
req->cmd_flags |= REQ_NOMERGE;
if (req == q->last_merge)
@@ -290,7 +252,6 @@ static inline int ll_new_hw_segment(struct request_queue *q,
* This will form the start of a new hw segment. Bump both
* counters.
*/
- req->nr_hw_segments += nr_hw_segs;
req->nr_phys_segments += nr_phys_segs;
return 1;
}
@@ -299,7 +260,6 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio)
{
unsigned short max_sectors;
- int len;
if (unlikely(blk_pc_request(req)))
max_sectors = q->max_hw_sectors;
@@ -316,19 +276,6 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
blk_recount_segments(q, req->biotail);
if (!bio_flagged(bio, BIO_SEG_VALID))
blk_recount_segments(q, bio);
- len = req->biotail->bi_hw_back_size + bio->bi_hw_front_size;
- if (BIOVEC_VIRT_MERGEABLE(__BVEC_END(req->biotail), __BVEC_START(bio))
- && !BIOVEC_VIRT_OVERSIZE(len)) {
- int mergeable = ll_new_mergeable(q, req, bio);
-
- if (mergeable) {
- if (req->nr_hw_segments == 1)
- req->bio->bi_hw_front_size = len;
- if (bio->bi_hw_segments == 1)
- bio->bi_hw_back_size = len;
- }
- return mergeable;
- }
return ll_new_hw_segment(q, req, bio);
}
@@ -337,7 +284,6 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio)
{
unsigned short max_sectors;
- int len;
if (unlikely(blk_pc_request(req)))
max_sectors = q->max_hw_sectors;
@@ -351,23 +297,10 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
q->last_merge = NULL;
return 0;
}
- len = bio->bi_hw_back_size + req->bio->bi_hw_front_size;
if (!bio_flagged(bio, BIO_SEG_VALID))
blk_recount_segments(q, bio);
if (!bio_flagged(req->bio, BIO_SEG_VALID))
blk_recount_segments(q, req->bio);
- if (BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(req->bio)) &&
- !BIOVEC_VIRT_OVERSIZE(len)) {
- int mergeable = ll_new_mergeable(q, req, bio);
-
- if (mergeable) {
- if (bio->bi_hw_segments == 1)
- bio->bi_hw_front_size = len;
- if (req->nr_hw_segments == 1)
- req->biotail->bi_hw_back_size = len;
- }
- return mergeable;
- }
return ll_new_hw_segment(q, req, bio);
}
@@ -376,7 +309,6 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
struct request *next)
{
int total_phys_segments;
- int total_hw_segments;
/*
* First check if the either of the requests are re-queued
@@ -398,26 +330,11 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
if (total_phys_segments > q->max_phys_segments)
return 0;
- total_hw_segments = req->nr_hw_segments + next->nr_hw_segments;
- if (blk_hw_contig_segment(q, req->biotail, next->bio)) {
- int len = req->biotail->bi_hw_back_size +
- next->bio->bi_hw_front_size;
- /*
- * propagate the combined length to the end of the requests
- */
- if (req->nr_hw_segments == 1)
- req->bio->bi_hw_front_size = len;
- if (next->nr_hw_segments == 1)
- next->biotail->bi_hw_back_size = len;
- total_hw_segments--;
- }
-
- if (total_hw_segments > q->max_hw_segments)
+ if (total_phys_segments > q->max_hw_segments)
return 0;
/* Merge is OK... */
req->nr_phys_segments = total_phys_segments;
- req->nr_hw_segments = total_hw_segments;
return 1;
}
@@ -470,17 +387,21 @@ static int attempt_merge(struct request_queue *q, struct request *req,
elv_merge_requests(q, req, next);
if (req->rq_disk) {
- struct hd_struct *part
- = get_part(req->rq_disk, req->sector);
- disk_round_stats(req->rq_disk);
- req->rq_disk->in_flight--;
- if (part) {
- part_round_stats(part);
- part->in_flight--;
- }
+ struct hd_struct *part;
+ int cpu;
+
+ cpu = part_stat_lock();
+ part = disk_map_sector_rcu(req->rq_disk, req->sector);
+
+ part_round_stats(cpu, part);
+ part_dec_in_flight(part);
+
+ part_stat_unlock();
}
req->ioprio = ioprio_best(req->ioprio, next->ioprio);
+ if (blk_rq_cpu_valid(next))
+ req->cpu = next->cpu;
__blk_put_request(q, next);
return 1;