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