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1/*
2 * blk-integrity.c - Block layer data integrity extensions
3 *
4 * Copyright (C) 2007, 2008 Oracle Corporation
5 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; see the file COPYING. If not, write to
18 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
19 * USA.
20 *
21 */
22
23#include <linux/blkdev.h>
24#include <linux/backing-dev.h>
25#include <linux/mempool.h>
26#include <linux/bio.h>
27#include <linux/scatterlist.h>
28#include <linux/export.h>
29#include <linux/slab.h>
30
31#include "blk.h"
32
33/**
34 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
35 * @q: request queue
36 * @bio: bio with integrity metadata attached
37 *
38 * Description: Returns the number of elements required in a
39 * scatterlist corresponding to the integrity metadata in a bio.
40 */
41int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
42{
43 struct bio_vec iv, ivprv = { NULL };
44 unsigned int segments = 0;
45 unsigned int seg_size = 0;
46 struct bvec_iter iter;
47 int prev = 0;
48
49 bio_for_each_integrity_vec(iv, bio, iter) {
50
51 if (prev) {
52 if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
53 goto new_segment;
54
55 if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
56 goto new_segment;
57
58 if (seg_size + iv.bv_len > queue_max_segment_size(q))
59 goto new_segment;
60
61 seg_size += iv.bv_len;
62 } else {
63new_segment:
64 segments++;
65 seg_size = iv.bv_len;
66 }
67
68 prev = 1;
69 ivprv = iv;
70 }
71
72 return segments;
73}
74EXPORT_SYMBOL(blk_rq_count_integrity_sg);
75
76/**
77 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
78 * @q: request queue
79 * @bio: bio with integrity metadata attached
80 * @sglist: target scatterlist
81 *
82 * Description: Map the integrity vectors in request into a
83 * scatterlist. The scatterlist must be big enough to hold all
84 * elements. I.e. sized using blk_rq_count_integrity_sg().
85 */
86int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
87 struct scatterlist *sglist)
88{
89 struct bio_vec iv, ivprv = { NULL };
90 struct scatterlist *sg = NULL;
91 unsigned int segments = 0;
92 struct bvec_iter iter;
93 int prev = 0;
94
95 bio_for_each_integrity_vec(iv, bio, iter) {
96
97 if (prev) {
98 if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
99 goto new_segment;
100
101 if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
102 goto new_segment;
103
104 if (sg->length + iv.bv_len > queue_max_segment_size(q))
105 goto new_segment;
106
107 sg->length += iv.bv_len;
108 } else {
109new_segment:
110 if (!sg)
111 sg = sglist;
112 else {
113 sg_unmark_end(sg);
114 sg = sg_next(sg);
115 }
116
117 sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
118 segments++;
119 }
120
121 prev = 1;
122 ivprv = iv;
123 }
124
125 if (sg)
126 sg_mark_end(sg);
127
128 return segments;
129}
130EXPORT_SYMBOL(blk_rq_map_integrity_sg);
131
132/**
133 * blk_integrity_compare - Compare integrity profile of two disks
134 * @gd1: Disk to compare
135 * @gd2: Disk to compare
136 *
137 * Description: Meta-devices like DM and MD need to verify that all
138 * sub-devices use the same integrity format before advertising to
139 * upper layers that they can send/receive integrity metadata. This
140 * function can be used to check whether two gendisk devices have
141 * compatible integrity formats.
142 */
143int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
144{
145 struct blk_integrity *b1 = &gd1->queue->integrity;
146 struct blk_integrity *b2 = &gd2->queue->integrity;
147
148 if (!b1->profile && !b2->profile)
149 return 0;
150
151 if (!b1->profile || !b2->profile)
152 return -1;
153
154 if (b1->interval_exp != b2->interval_exp) {
155 pr_err("%s: %s/%s protection interval %u != %u\n",
156 __func__, gd1->disk_name, gd2->disk_name,
157 1 << b1->interval_exp, 1 << b2->interval_exp);
158 return -1;
159 }
160
161 if (b1->tuple_size != b2->tuple_size) {
162 pr_err("%s: %s/%s tuple sz %u != %u\n", __func__,
163 gd1->disk_name, gd2->disk_name,
164 b1->tuple_size, b2->tuple_size);
165 return -1;
166 }
167
168 if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
169 pr_err("%s: %s/%s tag sz %u != %u\n", __func__,
170 gd1->disk_name, gd2->disk_name,
171 b1->tag_size, b2->tag_size);
172 return -1;
173 }
174
175 if (b1->profile != b2->profile) {
176 pr_err("%s: %s/%s type %s != %s\n", __func__,
177 gd1->disk_name, gd2->disk_name,
178 b1->profile->name, b2->profile->name);
179 return -1;
180 }
181
182 return 0;
183}
184EXPORT_SYMBOL(blk_integrity_compare);
185
186bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
187 struct request *next)
188{
189 if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
190 return true;
191
192 if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
193 return false;
194
195 if (bio_integrity(req->bio)->bip_flags !=
196 bio_integrity(next->bio)->bip_flags)
197 return false;
198
199 if (req->nr_integrity_segments + next->nr_integrity_segments >
200 q->limits.max_integrity_segments)
201 return false;
202
203 if (integrity_req_gap_back_merge(req, next->bio))
204 return false;
205
206 return true;
207}
208EXPORT_SYMBOL(blk_integrity_merge_rq);
209
210bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
211 struct bio *bio)
212{
213 int nr_integrity_segs;
214 struct bio *next = bio->bi_next;
215
216 if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
217 return true;
218
219 if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
220 return false;
221
222 if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
223 return false;
224
225 bio->bi_next = NULL;
226 nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
227 bio->bi_next = next;
228
229 if (req->nr_integrity_segments + nr_integrity_segs >
230 q->limits.max_integrity_segments)
231 return false;
232
233 req->nr_integrity_segments += nr_integrity_segs;
234
235 return true;
236}
237EXPORT_SYMBOL(blk_integrity_merge_bio);
238
239struct integrity_sysfs_entry {
240 struct attribute attr;
241 ssize_t (*show)(struct blk_integrity *, char *);
242 ssize_t (*store)(struct blk_integrity *, const char *, size_t);
243};
244
245static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
246 char *page)
247{
248 struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
249 struct blk_integrity *bi = &disk->queue->integrity;
250 struct integrity_sysfs_entry *entry =
251 container_of(attr, struct integrity_sysfs_entry, attr);
252
253 return entry->show(bi, page);
254}
255
256static ssize_t integrity_attr_store(struct kobject *kobj,
257 struct attribute *attr, const char *page,
258 size_t count)
259{
260 struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
261 struct blk_integrity *bi = &disk->queue->integrity;
262 struct integrity_sysfs_entry *entry =
263 container_of(attr, struct integrity_sysfs_entry, attr);
264 ssize_t ret = 0;
265
266 if (entry->store)
267 ret = entry->store(bi, page, count);
268
269 return ret;
270}
271
272static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
273{
274 if (bi->profile && bi->profile->name)
275 return sprintf(page, "%s\n", bi->profile->name);
276 else
277 return sprintf(page, "none\n");
278}
279
280static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
281{
282 return sprintf(page, "%u\n", bi->tag_size);
283}
284
285static ssize_t integrity_interval_show(struct blk_integrity *bi, char *page)
286{
287 return sprintf(page, "%u\n",
288 bi->interval_exp ? 1 << bi->interval_exp : 0);
289}
290
291static ssize_t integrity_verify_store(struct blk_integrity *bi,
292 const char *page, size_t count)
293{
294 char *p = (char *) page;
295 unsigned long val = simple_strtoul(p, &p, 10);
296
297 if (val)
298 bi->flags |= BLK_INTEGRITY_VERIFY;
299 else
300 bi->flags &= ~BLK_INTEGRITY_VERIFY;
301
302 return count;
303}
304
305static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
306{
307 return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
308}
309
310static ssize_t integrity_generate_store(struct blk_integrity *bi,
311 const char *page, size_t count)
312{
313 char *p = (char *) page;
314 unsigned long val = simple_strtoul(p, &p, 10);
315
316 if (val)
317 bi->flags |= BLK_INTEGRITY_GENERATE;
318 else
319 bi->flags &= ~BLK_INTEGRITY_GENERATE;
320
321 return count;
322}
323
324static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
325{
326 return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
327}
328
329static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
330{
331 return sprintf(page, "%u\n",
332 (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
333}
334
335static struct integrity_sysfs_entry integrity_format_entry = {
336 .attr = { .name = "format", .mode = S_IRUGO },
337 .show = integrity_format_show,
338};
339
340static struct integrity_sysfs_entry integrity_tag_size_entry = {
341 .attr = { .name = "tag_size", .mode = S_IRUGO },
342 .show = integrity_tag_size_show,
343};
344
345static struct integrity_sysfs_entry integrity_interval_entry = {
346 .attr = { .name = "protection_interval_bytes", .mode = S_IRUGO },
347 .show = integrity_interval_show,
348};
349
350static struct integrity_sysfs_entry integrity_verify_entry = {
351 .attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
352 .show = integrity_verify_show,
353 .store = integrity_verify_store,
354};
355
356static struct integrity_sysfs_entry integrity_generate_entry = {
357 .attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
358 .show = integrity_generate_show,
359 .store = integrity_generate_store,
360};
361
362static struct integrity_sysfs_entry integrity_device_entry = {
363 .attr = { .name = "device_is_integrity_capable", .mode = S_IRUGO },
364 .show = integrity_device_show,
365};
366
367static struct attribute *integrity_attrs[] = {
368 &integrity_format_entry.attr,
369 &integrity_tag_size_entry.attr,
370 &integrity_interval_entry.attr,
371 &integrity_verify_entry.attr,
372 &integrity_generate_entry.attr,
373 &integrity_device_entry.attr,
374 NULL,
375};
376
377static const struct sysfs_ops integrity_ops = {
378 .show = &integrity_attr_show,
379 .store = &integrity_attr_store,
380};
381
382static struct kobj_type integrity_ktype = {
383 .default_attrs = integrity_attrs,
384 .sysfs_ops = &integrity_ops,
385};
386
387static int blk_integrity_nop_fn(struct blk_integrity_iter *iter)
388{
389 return 0;
390}
391
392static struct blk_integrity_profile nop_profile = {
393 .name = "nop",
394 .generate_fn = blk_integrity_nop_fn,
395 .verify_fn = blk_integrity_nop_fn,
396};
397
398/**
399 * blk_integrity_register - Register a gendisk as being integrity-capable
400 * @disk: struct gendisk pointer to make integrity-aware
401 * @template: block integrity profile to register
402 *
403 * Description: When a device needs to advertise itself as being able to
404 * send/receive integrity metadata it must use this function to register
405 * the capability with the block layer. The template is a blk_integrity
406 * struct with values appropriate for the underlying hardware. See
407 * Documentation/block/data-integrity.txt.
408 */
409void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
410{
411 struct blk_integrity *bi = &disk->queue->integrity;
412
413 bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
414 template->flags;
415 bi->interval_exp = ilog2(queue_logical_block_size(disk->queue));
416 bi->profile = template->profile ? template->profile : &nop_profile;
417 bi->tuple_size = template->tuple_size;
418 bi->tag_size = template->tag_size;
419
420 blk_integrity_revalidate(disk);
421}
422EXPORT_SYMBOL(blk_integrity_register);
423
424/**
425 * blk_integrity_unregister - Unregister block integrity profile
426 * @disk: disk whose integrity profile to unregister
427 *
428 * Description: This function unregisters the integrity capability from
429 * a block device.
430 */
431void blk_integrity_unregister(struct gendisk *disk)
432{
433 blk_integrity_revalidate(disk);
434 memset(&disk->queue->integrity, 0, sizeof(struct blk_integrity));
435}
436EXPORT_SYMBOL(blk_integrity_unregister);
437
438void blk_integrity_revalidate(struct gendisk *disk)
439{
440 struct blk_integrity *bi = &disk->queue->integrity;
441
442 if (!(disk->flags & GENHD_FL_UP))
443 return;
444
445 if (bi->profile)
446 disk->queue->backing_dev_info.capabilities |=
447 BDI_CAP_STABLE_WRITES;
448 else
449 disk->queue->backing_dev_info.capabilities &=
450 ~BDI_CAP_STABLE_WRITES;
451}
452
453void blk_integrity_add(struct gendisk *disk)
454{
455 if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
456 &disk_to_dev(disk)->kobj, "%s", "integrity"))
457 return;
458
459 kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
460}
461
462void blk_integrity_del(struct gendisk *disk)
463{
464 kobject_uevent(&disk->integrity_kobj, KOBJ_REMOVE);
465 kobject_del(&disk->integrity_kobj);
466 kobject_put(&disk->integrity_kobj);
467}
1/*
2 * blk-integrity.c - Block layer data integrity extensions
3 *
4 * Copyright (C) 2007, 2008 Oracle Corporation
5 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; see the file COPYING. If not, write to
18 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
19 * USA.
20 *
21 */
22
23#include <linux/blkdev.h>
24#include <linux/mempool.h>
25#include <linux/bio.h>
26#include <linux/scatterlist.h>
27#include <linux/slab.h>
28
29#include "blk.h"
30
31static struct kmem_cache *integrity_cachep;
32
33static const char *bi_unsupported_name = "unsupported";
34
35/**
36 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
37 * @q: request queue
38 * @bio: bio with integrity metadata attached
39 *
40 * Description: Returns the number of elements required in a
41 * scatterlist corresponding to the integrity metadata in a bio.
42 */
43int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
44{
45 struct bio_vec *iv, *ivprv = NULL;
46 unsigned int segments = 0;
47 unsigned int seg_size = 0;
48 unsigned int i = 0;
49
50 bio_for_each_integrity_vec(iv, bio, i) {
51
52 if (ivprv) {
53 if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
54 goto new_segment;
55
56 if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
57 goto new_segment;
58
59 if (seg_size + iv->bv_len > queue_max_segment_size(q))
60 goto new_segment;
61
62 seg_size += iv->bv_len;
63 } else {
64new_segment:
65 segments++;
66 seg_size = iv->bv_len;
67 }
68
69 ivprv = iv;
70 }
71
72 return segments;
73}
74EXPORT_SYMBOL(blk_rq_count_integrity_sg);
75
76/**
77 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
78 * @q: request queue
79 * @bio: bio with integrity metadata attached
80 * @sglist: target scatterlist
81 *
82 * Description: Map the integrity vectors in request into a
83 * scatterlist. The scatterlist must be big enough to hold all
84 * elements. I.e. sized using blk_rq_count_integrity_sg().
85 */
86int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
87 struct scatterlist *sglist)
88{
89 struct bio_vec *iv, *ivprv = NULL;
90 struct scatterlist *sg = NULL;
91 unsigned int segments = 0;
92 unsigned int i = 0;
93
94 bio_for_each_integrity_vec(iv, bio, i) {
95
96 if (ivprv) {
97 if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
98 goto new_segment;
99
100 if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv))
101 goto new_segment;
102
103 if (sg->length + iv->bv_len > queue_max_segment_size(q))
104 goto new_segment;
105
106 sg->length += iv->bv_len;
107 } else {
108new_segment:
109 if (!sg)
110 sg = sglist;
111 else {
112 sg->page_link &= ~0x02;
113 sg = sg_next(sg);
114 }
115
116 sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset);
117 segments++;
118 }
119
120 ivprv = iv;
121 }
122
123 if (sg)
124 sg_mark_end(sg);
125
126 return segments;
127}
128EXPORT_SYMBOL(blk_rq_map_integrity_sg);
129
130/**
131 * blk_integrity_compare - Compare integrity profile of two disks
132 * @gd1: Disk to compare
133 * @gd2: Disk to compare
134 *
135 * Description: Meta-devices like DM and MD need to verify that all
136 * sub-devices use the same integrity format before advertising to
137 * upper layers that they can send/receive integrity metadata. This
138 * function can be used to check whether two gendisk devices have
139 * compatible integrity formats.
140 */
141int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
142{
143 struct blk_integrity *b1 = gd1->integrity;
144 struct blk_integrity *b2 = gd2->integrity;
145
146 if (!b1 && !b2)
147 return 0;
148
149 if (!b1 || !b2)
150 return -1;
151
152 if (b1->sector_size != b2->sector_size) {
153 printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
154 gd1->disk_name, gd2->disk_name,
155 b1->sector_size, b2->sector_size);
156 return -1;
157 }
158
159 if (b1->tuple_size != b2->tuple_size) {
160 printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
161 gd1->disk_name, gd2->disk_name,
162 b1->tuple_size, b2->tuple_size);
163 return -1;
164 }
165
166 if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
167 printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
168 gd1->disk_name, gd2->disk_name,
169 b1->tag_size, b2->tag_size);
170 return -1;
171 }
172
173 if (strcmp(b1->name, b2->name)) {
174 printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
175 gd1->disk_name, gd2->disk_name,
176 b1->name, b2->name);
177 return -1;
178 }
179
180 return 0;
181}
182EXPORT_SYMBOL(blk_integrity_compare);
183
184int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
185 struct request *next)
186{
187 if (blk_integrity_rq(req) != blk_integrity_rq(next))
188 return -1;
189
190 if (req->nr_integrity_segments + next->nr_integrity_segments >
191 q->limits.max_integrity_segments)
192 return -1;
193
194 return 0;
195}
196EXPORT_SYMBOL(blk_integrity_merge_rq);
197
198int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
199 struct bio *bio)
200{
201 int nr_integrity_segs;
202 struct bio *next = bio->bi_next;
203
204 bio->bi_next = NULL;
205 nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
206 bio->bi_next = next;
207
208 if (req->nr_integrity_segments + nr_integrity_segs >
209 q->limits.max_integrity_segments)
210 return -1;
211
212 req->nr_integrity_segments += nr_integrity_segs;
213
214 return 0;
215}
216EXPORT_SYMBOL(blk_integrity_merge_bio);
217
218struct integrity_sysfs_entry {
219 struct attribute attr;
220 ssize_t (*show)(struct blk_integrity *, char *);
221 ssize_t (*store)(struct blk_integrity *, const char *, size_t);
222};
223
224static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
225 char *page)
226{
227 struct blk_integrity *bi =
228 container_of(kobj, struct blk_integrity, kobj);
229 struct integrity_sysfs_entry *entry =
230 container_of(attr, struct integrity_sysfs_entry, attr);
231
232 return entry->show(bi, page);
233}
234
235static ssize_t integrity_attr_store(struct kobject *kobj,
236 struct attribute *attr, const char *page,
237 size_t count)
238{
239 struct blk_integrity *bi =
240 container_of(kobj, struct blk_integrity, kobj);
241 struct integrity_sysfs_entry *entry =
242 container_of(attr, struct integrity_sysfs_entry, attr);
243 ssize_t ret = 0;
244
245 if (entry->store)
246 ret = entry->store(bi, page, count);
247
248 return ret;
249}
250
251static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
252{
253 if (bi != NULL && bi->name != NULL)
254 return sprintf(page, "%s\n", bi->name);
255 else
256 return sprintf(page, "none\n");
257}
258
259static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
260{
261 if (bi != NULL)
262 return sprintf(page, "%u\n", bi->tag_size);
263 else
264 return sprintf(page, "0\n");
265}
266
267static ssize_t integrity_read_store(struct blk_integrity *bi,
268 const char *page, size_t count)
269{
270 char *p = (char *) page;
271 unsigned long val = simple_strtoul(p, &p, 10);
272
273 if (val)
274 bi->flags |= INTEGRITY_FLAG_READ;
275 else
276 bi->flags &= ~INTEGRITY_FLAG_READ;
277
278 return count;
279}
280
281static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
282{
283 return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
284}
285
286static ssize_t integrity_write_store(struct blk_integrity *bi,
287 const char *page, size_t count)
288{
289 char *p = (char *) page;
290 unsigned long val = simple_strtoul(p, &p, 10);
291
292 if (val)
293 bi->flags |= INTEGRITY_FLAG_WRITE;
294 else
295 bi->flags &= ~INTEGRITY_FLAG_WRITE;
296
297 return count;
298}
299
300static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
301{
302 return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
303}
304
305static struct integrity_sysfs_entry integrity_format_entry = {
306 .attr = { .name = "format", .mode = S_IRUGO },
307 .show = integrity_format_show,
308};
309
310static struct integrity_sysfs_entry integrity_tag_size_entry = {
311 .attr = { .name = "tag_size", .mode = S_IRUGO },
312 .show = integrity_tag_size_show,
313};
314
315static struct integrity_sysfs_entry integrity_read_entry = {
316 .attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
317 .show = integrity_read_show,
318 .store = integrity_read_store,
319};
320
321static struct integrity_sysfs_entry integrity_write_entry = {
322 .attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
323 .show = integrity_write_show,
324 .store = integrity_write_store,
325};
326
327static struct attribute *integrity_attrs[] = {
328 &integrity_format_entry.attr,
329 &integrity_tag_size_entry.attr,
330 &integrity_read_entry.attr,
331 &integrity_write_entry.attr,
332 NULL,
333};
334
335static const struct sysfs_ops integrity_ops = {
336 .show = &integrity_attr_show,
337 .store = &integrity_attr_store,
338};
339
340static int __init blk_dev_integrity_init(void)
341{
342 integrity_cachep = kmem_cache_create("blkdev_integrity",
343 sizeof(struct blk_integrity),
344 0, SLAB_PANIC, NULL);
345 return 0;
346}
347subsys_initcall(blk_dev_integrity_init);
348
349static void blk_integrity_release(struct kobject *kobj)
350{
351 struct blk_integrity *bi =
352 container_of(kobj, struct blk_integrity, kobj);
353
354 kmem_cache_free(integrity_cachep, bi);
355}
356
357static struct kobj_type integrity_ktype = {
358 .default_attrs = integrity_attrs,
359 .sysfs_ops = &integrity_ops,
360 .release = blk_integrity_release,
361};
362
363bool blk_integrity_is_initialized(struct gendisk *disk)
364{
365 struct blk_integrity *bi = blk_get_integrity(disk);
366
367 return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
368}
369EXPORT_SYMBOL(blk_integrity_is_initialized);
370
371/**
372 * blk_integrity_register - Register a gendisk as being integrity-capable
373 * @disk: struct gendisk pointer to make integrity-aware
374 * @template: optional integrity profile to register
375 *
376 * Description: When a device needs to advertise itself as being able
377 * to send/receive integrity metadata it must use this function to
378 * register the capability with the block layer. The template is a
379 * blk_integrity struct with values appropriate for the underlying
380 * hardware. If template is NULL the new profile is allocated but
381 * not filled out. See Documentation/block/data-integrity.txt.
382 */
383int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
384{
385 struct blk_integrity *bi;
386
387 BUG_ON(disk == NULL);
388
389 if (disk->integrity == NULL) {
390 bi = kmem_cache_alloc(integrity_cachep,
391 GFP_KERNEL | __GFP_ZERO);
392 if (!bi)
393 return -1;
394
395 if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
396 &disk_to_dev(disk)->kobj,
397 "%s", "integrity")) {
398 kmem_cache_free(integrity_cachep, bi);
399 return -1;
400 }
401
402 kobject_uevent(&bi->kobj, KOBJ_ADD);
403
404 bi->flags |= INTEGRITY_FLAG_READ | INTEGRITY_FLAG_WRITE;
405 bi->sector_size = queue_logical_block_size(disk->queue);
406 disk->integrity = bi;
407 } else
408 bi = disk->integrity;
409
410 /* Use the provided profile as template */
411 if (template != NULL) {
412 bi->name = template->name;
413 bi->generate_fn = template->generate_fn;
414 bi->verify_fn = template->verify_fn;
415 bi->tuple_size = template->tuple_size;
416 bi->set_tag_fn = template->set_tag_fn;
417 bi->get_tag_fn = template->get_tag_fn;
418 bi->tag_size = template->tag_size;
419 } else
420 bi->name = bi_unsupported_name;
421
422 return 0;
423}
424EXPORT_SYMBOL(blk_integrity_register);
425
426/**
427 * blk_integrity_unregister - Remove block integrity profile
428 * @disk: disk whose integrity profile to deallocate
429 *
430 * Description: This function frees all memory used by the block
431 * integrity profile. To be called at device teardown.
432 */
433void blk_integrity_unregister(struct gendisk *disk)
434{
435 struct blk_integrity *bi;
436
437 if (!disk || !disk->integrity)
438 return;
439
440 bi = disk->integrity;
441
442 kobject_uevent(&bi->kobj, KOBJ_REMOVE);
443 kobject_del(&bi->kobj);
444 kobject_put(&bi->kobj);
445 disk->integrity = NULL;
446}
447EXPORT_SYMBOL(blk_integrity_unregister);