aboutsummaryrefslogtreecommitdiffstats
path: root/block/blk-merge.c
diff options
context:
space:
mode:
Diffstat (limited to 'block/blk-merge.c')
-rw-r--r--block/blk-merge.c93
1 files changed, 49 insertions, 44 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index b92f5b0866b0..5a244f05360f 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -38,72 +38,77 @@ void blk_recalc_rq_sectors(struct request *rq, int nsect)
38 } 38 }
39} 39}
40 40
41void blk_recalc_rq_segments(struct request *rq) 41static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
42 struct bio *bio)
42{ 43{
43 int nr_phys_segs;
44 unsigned int phys_size; 44 unsigned int phys_size;
45 struct bio_vec *bv, *bvprv = NULL; 45 struct bio_vec *bv, *bvprv = NULL;
46 int seg_size; 46 int cluster, i, high, highprv = 1;
47 int cluster; 47 unsigned int seg_size, nr_phys_segs;
48 struct req_iterator iter; 48 struct bio *fbio, *bbio;
49 int high, highprv = 1;
50 struct request_queue *q = rq->q;
51 49
52 if (!rq->bio) 50 if (!bio)
53 return; 51 return 0;
54 52
53 fbio = bio;
55 cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); 54 cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
56 seg_size = 0; 55 seg_size = 0;
57 phys_size = nr_phys_segs = 0; 56 phys_size = nr_phys_segs = 0;
58 rq_for_each_segment(bv, rq, iter) { 57 for_each_bio(bio) {
59 /* 58 bio_for_each_segment(bv, bio, i) {
60 * the trick here is making sure that a high page is never 59 /*
61 * considered part of another segment, since that might 60 * the trick here is making sure that a high page is
62 * change with the bounce page. 61 * never considered part of another segment, since that
63 */ 62 * might change with the bounce page.
64 high = page_to_pfn(bv->bv_page) > q->bounce_pfn; 63 */
65 if (high || highprv) 64 high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
66 goto new_segment; 65 if (high || highprv)
67 if (cluster) {
68 if (seg_size + bv->bv_len > q->max_segment_size)
69 goto new_segment;
70 if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
71 goto new_segment;
72 if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
73 goto new_segment; 66 goto new_segment;
67 if (cluster) {
68 if (seg_size + bv->bv_len > q->max_segment_size)
69 goto new_segment;
70 if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
71 goto new_segment;
72 if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
73 goto new_segment;
74
75 seg_size += bv->bv_len;
76 bvprv = bv;
77 continue;
78 }
79new_segment:
80 if (nr_phys_segs == 1 && seg_size >
81 fbio->bi_seg_front_size)
82 fbio->bi_seg_front_size = seg_size;
74 83
75 seg_size += bv->bv_len; 84 nr_phys_segs++;
76 bvprv = bv; 85 bvprv = bv;
77 continue; 86 seg_size = bv->bv_len;
87 highprv = high;
78 } 88 }
79new_segment: 89 bbio = bio;
80 if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size)
81 rq->bio->bi_seg_front_size = seg_size;
82
83 nr_phys_segs++;
84 bvprv = bv;
85 seg_size = bv->bv_len;
86 highprv = high;
87 } 90 }
88 91
89 if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size) 92 if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size)
90 rq->bio->bi_seg_front_size = seg_size; 93 fbio->bi_seg_front_size = seg_size;
91 if (seg_size > rq->biotail->bi_seg_back_size) 94 if (seg_size > bbio->bi_seg_back_size)
92 rq->biotail->bi_seg_back_size = seg_size; 95 bbio->bi_seg_back_size = seg_size;
96
97 return nr_phys_segs;
98}
93 99
94 rq->nr_phys_segments = nr_phys_segs; 100void blk_recalc_rq_segments(struct request *rq)
101{
102 rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio);
95} 103}
96 104
97void blk_recount_segments(struct request_queue *q, struct bio *bio) 105void blk_recount_segments(struct request_queue *q, struct bio *bio)
98{ 106{
99 struct request rq;
100 struct bio *nxt = bio->bi_next; 107 struct bio *nxt = bio->bi_next;
101 rq.q = q; 108
102 rq.bio = rq.biotail = bio;
103 bio->bi_next = NULL; 109 bio->bi_next = NULL;
104 blk_recalc_rq_segments(&rq); 110 bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio);
105 bio->bi_next = nxt; 111 bio->bi_next = nxt;
106 bio->bi_phys_segments = rq.nr_phys_segments;
107 bio->bi_flags |= (1 << BIO_SEG_VALID); 112 bio->bi_flags |= (1 << BIO_SEG_VALID);
108} 113}
109EXPORT_SYMBOL(blk_recount_segments); 114EXPORT_SYMBOL(blk_recount_segments);