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;
}
}
-void blk_recalc_rq_segments(struct request *rq)
+static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
+ struct bio *bio)
{
- 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;
- struct request_queue *q = rq->q;
+ int cluster, i, high, highprv = 1;
+ unsigned int seg_size, nr_phys_segs;
+ struct bio *fbio, *bbio;
- if (!rq->bio)
- return;
+ if (!bio)
+ return 0;
+ fbio = bio;
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;
- rq_for_each_segment(bv, rq, iter) {
- /*
- * 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) > q->bounce_pfn;
- if (high || highprv)
- goto new_hw_segment;
- if (cluster) {
- if (seg_size + bv->bv_len > q->max_segment_size)
+ 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) > q->bounce_pfn;
+ if (high || highprv)
goto new_segment;
- if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
- 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;
+ if (cluster) {
+ if (seg_size + bv->bv_len > q->max_segment_size)
+ 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;
- seg_size += bv->bv_len;
- hw_seg_size += bv->bv_len;
+ nr_phys_segs++;
bvprv = bv;
- continue;
+ seg_size = bv->bv_len;
+ highprv = high;
}
-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;
+ bbio = bio;
}
- 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;
+ 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;
+}
+
+void blk_recalc_rq_segments(struct request *rq)
+{
+ rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio);
}
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
- struct request rq;
struct bio *nxt = bio->bi_next;
- rq.q = q;
- rq.bio = rq.biotail = bio;
+
bio->bi_next = NULL;
- blk_recalc_rq_segments(&rq);
+ bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio);
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);
if (!test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
return 0;
- if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)))
+ if (bio->bi_seg_back_size + nxt->bi_seg_front_size >
+ q->max_segment_size)
return 0;
- if (bio->bi_size + nxt->bi_size > q->max_segment_size)
+
+ 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))
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
}
EXPORT_SYMBOL(blk_rq_map_sg);
-static inline int ll_new_mergeable(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 > q->max_phys_segments) {
- req->cmd_flags |= REQ_NOMERGE;
- if (req == q->last_merge)
- q->last_merge = NULL;
- return 0;
- }
-
- /*
- * A hw segment is just getting larger, bump just the phys
- * counter.
- */
- req->nr_phys_segments += nr_phys_segs;
- return 1;
-}
-
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)
* 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;
}
struct bio *bio)
{
unsigned short max_sectors;
- int len;
if (unlikely(blk_pc_request(req)))
max_sectors = q->max_hw_sectors;
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);
}
struct bio *bio)
{
unsigned short max_sectors;
- int len;
if (unlikely(blk_pc_request(req)))
max_sectors = q->max_hw_sectors;
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);
}
struct request *next)
{
int total_phys_segments;
- int total_hw_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
return 0;
total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
- if (blk_phys_contig_segment(q, req->biotail, next->bio))
+ 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 > 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;
}
+static void blk_account_io_merge(struct request *req)
+{
+ if (blk_do_io_stat(req)) {
+ 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();
+ }
+}
+
/*
* Has to be called with the request spinlock acquired
*/
|| next->special)
return 0;
+ if (blk_integrity_rq(req) != blk_integrity_rq(next))
+ return 0;
+
/*
* If we are allowed to merge, then append bio list
* from next to rq and release next. merge_requests_fn
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--;
- }
- }
+ /*
+ * 'next' is going away, so update stats accordingly
+ */
+ blk_account_io_merge(next);
req->ioprio = ioprio_best(req->ioprio, next->ioprio);
+ if (blk_rq_cpu_valid(next))
+ req->cpu = next->cpu;
+ /* owner-ship of bio passed from next to req */
+ next->bio = NULL;
__blk_put_request(q, next);
return 1;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff