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authorMartin K. Petersen2010-09-10 13:50:10 -0500
committerJens Axboe2010-09-10 13:50:10 -0500
commit13f05c8d8e98bbdce89158bfdb2e380940695a88 (patch)
tree055215e7e2b1bdc684ead64daa61b30b35eaa3c5 /block
parentc8bf1336824ebd698d37b71763e1c43190f2229a (diff)
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block/scsi: Provide a limit on the number of integrity segments
Some controllers have a hardware limit on the number of protection information scatter-gather list segments they can handle. Introduce a max_integrity_segments limit in the block layer and provide a new scsi_host_template setting that allows HBA drivers to provide a value suitable for the hardware. Add support for honoring the integrity segment limit when merging both bios and requests. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-integrity.c93
-rw-r--r--block/blk-merge.c23
-rw-r--r--block/blk-settings.c3
-rw-r--r--block/blk-sysfs.c11
-rw-r--r--block/blk.h8
5 files changed, 100 insertions, 38 deletions
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index edce1ef7933..885cbb59967 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -32,24 +32,37 @@ static struct kmem_cache *integrity_cachep;
32 32
33/** 33/**
34 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements 34 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
35 * @rq: request with integrity metadata attached 35 * @q: request queue
36 * @bio: bio with integrity metadata attached
36 * 37 *
37 * Description: Returns the number of elements required in a 38 * Description: Returns the number of elements required in a
38 * scatterlist corresponding to the integrity metadata in a request. 39 * scatterlist corresponding to the integrity metadata in a bio.
39 */ 40 */
40int blk_rq_count_integrity_sg(struct request *rq) 41int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
41{ 42{
42 struct bio_vec *iv, *ivprv; 43 struct bio_vec *iv, *ivprv = NULL;
43 struct req_iterator iter; 44 unsigned int segments = 0;
44 unsigned int segments; 45 unsigned int seg_size = 0;
46 unsigned int i = 0;
45 47
46 ivprv = NULL; 48 bio_for_each_integrity_vec(iv, bio, i) {
47 segments = 0;
48 49
49 rq_for_each_integrity_segment(iv, rq, iter) { 50 if (ivprv) {
51 if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
52 goto new_segment;
53
54 if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
55 goto new_segment;
56
57 if (seg_size + iv->bv_len > queue_max_segment_size(q))
58 goto new_segment;
50 59
51 if (!ivprv || !BIOVEC_PHYS_MERGEABLE(ivprv, iv)) 60 seg_size += iv->bv_len;
61 } else {
62new_segment:
52 segments++; 63 segments++;
64 seg_size = iv->bv_len;
65 }
53 66
54 ivprv = iv; 67 ivprv = iv;
55 } 68 }
@@ -60,30 +73,34 @@ EXPORT_SYMBOL(blk_rq_count_integrity_sg);
60 73
61/** 74/**
62 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist 75 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
63 * @rq: request with integrity metadata attached 76 * @q: request queue
77 * @bio: bio with integrity metadata attached
64 * @sglist: target scatterlist 78 * @sglist: target scatterlist
65 * 79 *
66 * Description: Map the integrity vectors in request into a 80 * Description: Map the integrity vectors in request into a
67 * scatterlist. The scatterlist must be big enough to hold all 81 * scatterlist. The scatterlist must be big enough to hold all
68 * elements. I.e. sized using blk_rq_count_integrity_sg(). 82 * elements. I.e. sized using blk_rq_count_integrity_sg().
69 */ 83 */
70int blk_rq_map_integrity_sg(struct request *rq, struct scatterlist *sglist) 84int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
85 struct scatterlist *sglist)
71{ 86{
72 struct bio_vec *iv, *ivprv; 87 struct bio_vec *iv, *ivprv = NULL;
73 struct req_iterator iter; 88 struct scatterlist *sg = NULL;
74 struct scatterlist *sg; 89 unsigned int segments = 0;
75 unsigned int segments; 90 unsigned int i = 0;
76 91
77 ivprv = NULL; 92 bio_for_each_integrity_vec(iv, bio, i) {
78 sg = NULL;
79 segments = 0;
80
81 rq_for_each_integrity_segment(iv, rq, iter) {
82 93
83 if (ivprv) { 94 if (ivprv) {
84 if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv)) 95 if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
85 goto new_segment; 96 goto new_segment;
86 97
98 if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
99 goto new_segment;
100
101 if (sg->length + iv->bv_len > queue_max_segment_size(q))
102 goto new_segment;
103
87 sg->length += iv->bv_len; 104 sg->length += iv->bv_len;
88 } else { 105 } else {
89new_segment: 106new_segment:
@@ -162,6 +179,40 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
162} 179}
163EXPORT_SYMBOL(blk_integrity_compare); 180EXPORT_SYMBOL(blk_integrity_compare);
164 181
182int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
183 struct request *next)
184{
185 if (blk_integrity_rq(req) != blk_integrity_rq(next))
186 return -1;
187
188 if (req->nr_integrity_segments + next->nr_integrity_segments >
189 q->limits.max_integrity_segments)
190 return -1;
191
192 return 0;
193}
194EXPORT_SYMBOL(blk_integrity_merge_rq);
195
196int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
197 struct bio *bio)
198{
199 int nr_integrity_segs;
200 struct bio *next = bio->bi_next;
201
202 bio->bi_next = NULL;
203 nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
204 bio->bi_next = next;
205
206 if (req->nr_integrity_segments + nr_integrity_segs >
207 q->limits.max_integrity_segments)
208 return -1;
209
210 req->nr_integrity_segments += nr_integrity_segs;
211
212 return 0;
213}
214EXPORT_SYMBOL(blk_integrity_merge_bio);
215
165struct integrity_sysfs_entry { 216struct integrity_sysfs_entry {
166 struct attribute attr; 217 struct attribute attr;
167 ssize_t (*show)(struct blk_integrity *, char *); 218 ssize_t (*show)(struct blk_integrity *, char *);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 3b0cd424967..6a725461654 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -205,12 +205,11 @@ static inline int ll_new_hw_segment(struct request_queue *q,
205{ 205{
206 int nr_phys_segs = bio_phys_segments(q, bio); 206 int nr_phys_segs = bio_phys_segments(q, bio);
207 207
208 if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q)) { 208 if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q))
209 req->cmd_flags |= REQ_NOMERGE; 209 goto no_merge;
210 if (req == q->last_merge) 210
211 q->last_merge = NULL; 211 if (bio_integrity(bio) && blk_integrity_merge_bio(q, req, bio))
212 return 0; 212 goto no_merge;
213 }
214 213
215 /* 214 /*
216 * This will form the start of a new hw segment. Bump both 215 * This will form the start of a new hw segment. Bump both
@@ -218,6 +217,12 @@ static inline int ll_new_hw_segment(struct request_queue *q,
218 */ 217 */
219 req->nr_phys_segments += nr_phys_segs; 218 req->nr_phys_segments += nr_phys_segs;
220 return 1; 219 return 1;
220
221no_merge:
222 req->cmd_flags |= REQ_NOMERGE;
223 if (req == q->last_merge)
224 q->last_merge = NULL;
225 return 0;
221} 226}
222 227
223int ll_back_merge_fn(struct request_queue *q, struct request *req, 228int ll_back_merge_fn(struct request_queue *q, struct request *req,
@@ -301,6 +306,9 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
301 if (total_phys_segments > queue_max_segments(q)) 306 if (total_phys_segments > queue_max_segments(q))
302 return 0; 307 return 0;
303 308
309 if (blk_integrity_rq(req) && blk_integrity_merge_rq(q, req, next))
310 return 0;
311
304 /* Merge is OK... */ 312 /* Merge is OK... */
305 req->nr_phys_segments = total_phys_segments; 313 req->nr_phys_segments = total_phys_segments;
306 return 1; 314 return 1;
@@ -372,9 +380,6 @@ static int attempt_merge(struct request_queue *q, struct request *req,
372 || next->special) 380 || next->special)
373 return 0; 381 return 0;
374 382
375 if (blk_integrity_rq(req) != blk_integrity_rq(next))
376 return 0;
377
378 /* 383 /*
379 * If we are allowed to merge, then append bio list 384 * If we are allowed to merge, then append bio list
380 * from next to rq and release next. merge_requests_fn 385 * from next to rq and release next. merge_requests_fn
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 8d592b559bd..f8f2ddf2061 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -111,6 +111,7 @@ EXPORT_SYMBOL_GPL(blk_queue_lld_busy);
111void blk_set_default_limits(struct queue_limits *lim) 111void blk_set_default_limits(struct queue_limits *lim)
112{ 112{
113 lim->max_segments = BLK_MAX_SEGMENTS; 113 lim->max_segments = BLK_MAX_SEGMENTS;
114 lim->max_integrity_segments = 0;
114 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; 115 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
115 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; 116 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
116 lim->max_sectors = BLK_DEF_MAX_SECTORS; 117 lim->max_sectors = BLK_DEF_MAX_SECTORS;
@@ -509,6 +510,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
509 b->seg_boundary_mask); 510 b->seg_boundary_mask);
510 511
511 t->max_segments = min_not_zero(t->max_segments, b->max_segments); 512 t->max_segments = min_not_zero(t->max_segments, b->max_segments);
513 t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
514 b->max_integrity_segments);
512 515
513 t->max_segment_size = min_not_zero(t->max_segment_size, 516 t->max_segment_size = min_not_zero(t->max_segment_size,
514 b->max_segment_size); 517 b->max_segment_size);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 001ab18078f..b014f7739e9 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -112,6 +112,11 @@ static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
112 return queue_var_show(queue_max_segments(q), (page)); 112 return queue_var_show(queue_max_segments(q), (page));
113} 113}
114 114
115static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
116{
117 return queue_var_show(q->limits.max_integrity_segments, (page));
118}
119
115static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) 120static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
116{ 121{
117 if (test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags)) 122 if (test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
@@ -288,6 +293,11 @@ static struct queue_sysfs_entry queue_max_segments_entry = {
288 .show = queue_max_segments_show, 293 .show = queue_max_segments_show,
289}; 294};
290 295
296static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
297 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
298 .show = queue_max_integrity_segments_show,
299};
300
291static struct queue_sysfs_entry queue_max_segment_size_entry = { 301static struct queue_sysfs_entry queue_max_segment_size_entry = {
292 .attr = {.name = "max_segment_size", .mode = S_IRUGO }, 302 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
293 .show = queue_max_segment_size_show, 303 .show = queue_max_segment_size_show,
@@ -375,6 +385,7 @@ static struct attribute *default_attrs[] = {
375 &queue_max_hw_sectors_entry.attr, 385 &queue_max_hw_sectors_entry.attr,
376 &queue_max_sectors_entry.attr, 386 &queue_max_sectors_entry.attr,
377 &queue_max_segments_entry.attr, 387 &queue_max_segments_entry.attr,
388 &queue_max_integrity_segments_entry.attr,
378 &queue_max_segment_size_entry.attr, 389 &queue_max_segment_size_entry.attr,
379 &queue_iosched_entry.attr, 390 &queue_iosched_entry.attr,
380 &queue_hw_sector_size_entry.attr, 391 &queue_hw_sector_size_entry.attr,
diff --git a/block/blk.h b/block/blk.h
index 6e7dc87141e..6738831ba44 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -132,14 +132,6 @@ static inline int queue_congestion_off_threshold(struct request_queue *q)
132 return q->nr_congestion_off; 132 return q->nr_congestion_off;
133} 133}
134 134
135#if defined(CONFIG_BLK_DEV_INTEGRITY)
136
137#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
138 __rq_for_each_bio(_iter.bio, _rq) \
139 bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
140
141#endif /* BLK_DEV_INTEGRITY */
142
143static inline int blk_cpu_to_group(int cpu) 135static inline int blk_cpu_to_group(int cpu)
144{ 136{
145#ifdef CONFIG_SCHED_MC 137#ifdef CONFIG_SCHED_MC