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7ba1ba12 MP |
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> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
7ba1ba12 MP |
28 | |
29 | #include "blk.h" | |
30 | ||
31 | static struct kmem_cache *integrity_cachep; | |
32 | ||
33 | /** | |
34 | * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements | |
13f05c8d MP |
35 | * @q: request queue |
36 | * @bio: bio with integrity metadata attached | |
7ba1ba12 MP |
37 | * |
38 | * Description: Returns the number of elements required in a | |
13f05c8d | 39 | * scatterlist corresponding to the integrity metadata in a bio. |
7ba1ba12 | 40 | */ |
13f05c8d | 41 | int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio) |
7ba1ba12 | 42 | { |
13f05c8d MP |
43 | struct bio_vec *iv, *ivprv = NULL; |
44 | unsigned int segments = 0; | |
45 | unsigned int seg_size = 0; | |
46 | unsigned int i = 0; | |
7ba1ba12 | 47 | |
13f05c8d | 48 | bio_for_each_integrity_vec(iv, bio, i) { |
7ba1ba12 | 49 | |
13f05c8d MP |
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; | |
7ba1ba12 | 59 | |
13f05c8d MP |
60 | seg_size += iv->bv_len; |
61 | } else { | |
62 | new_segment: | |
7ba1ba12 | 63 | segments++; |
13f05c8d MP |
64 | seg_size = iv->bv_len; |
65 | } | |
7ba1ba12 MP |
66 | |
67 | ivprv = iv; | |
68 | } | |
69 | ||
70 | return segments; | |
71 | } | |
72 | EXPORT_SYMBOL(blk_rq_count_integrity_sg); | |
73 | ||
74 | /** | |
75 | * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist | |
13f05c8d MP |
76 | * @q: request queue |
77 | * @bio: bio with integrity metadata attached | |
7ba1ba12 MP |
78 | * @sglist: target scatterlist |
79 | * | |
80 | * Description: Map the integrity vectors in request into a | |
81 | * scatterlist. The scatterlist must be big enough to hold all | |
82 | * elements. I.e. sized using blk_rq_count_integrity_sg(). | |
83 | */ | |
13f05c8d MP |
84 | int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio, |
85 | struct scatterlist *sglist) | |
7ba1ba12 | 86 | { |
13f05c8d MP |
87 | struct bio_vec *iv, *ivprv = NULL; |
88 | struct scatterlist *sg = NULL; | |
89 | unsigned int segments = 0; | |
90 | unsigned int i = 0; | |
7ba1ba12 | 91 | |
13f05c8d | 92 | bio_for_each_integrity_vec(iv, bio, i) { |
7ba1ba12 MP |
93 | |
94 | if (ivprv) { | |
95 | if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv)) | |
96 | goto new_segment; | |
97 | ||
13f05c8d MP |
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 | ||
7ba1ba12 MP |
104 | sg->length += iv->bv_len; |
105 | } else { | |
106 | new_segment: | |
107 | if (!sg) | |
108 | sg = sglist; | |
109 | else { | |
110 | sg->page_link &= ~0x02; | |
111 | sg = sg_next(sg); | |
112 | } | |
113 | ||
114 | sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset); | |
115 | segments++; | |
116 | } | |
117 | ||
118 | ivprv = iv; | |
119 | } | |
120 | ||
121 | if (sg) | |
122 | sg_mark_end(sg); | |
123 | ||
124 | return segments; | |
125 | } | |
126 | EXPORT_SYMBOL(blk_rq_map_integrity_sg); | |
127 | ||
128 | /** | |
ad7fce93 MP |
129 | * blk_integrity_compare - Compare integrity profile of two disks |
130 | * @gd1: Disk to compare | |
131 | * @gd2: Disk to compare | |
7ba1ba12 MP |
132 | * |
133 | * Description: Meta-devices like DM and MD need to verify that all | |
134 | * sub-devices use the same integrity format before advertising to | |
135 | * upper layers that they can send/receive integrity metadata. This | |
ad7fce93 | 136 | * function can be used to check whether two gendisk devices have |
7ba1ba12 MP |
137 | * compatible integrity formats. |
138 | */ | |
ad7fce93 | 139 | int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2) |
7ba1ba12 | 140 | { |
ad7fce93 MP |
141 | struct blk_integrity *b1 = gd1->integrity; |
142 | struct blk_integrity *b2 = gd2->integrity; | |
7ba1ba12 | 143 | |
ad7fce93 MP |
144 | if (!b1 && !b2) |
145 | return 0; | |
7ba1ba12 MP |
146 | |
147 | if (!b1 || !b2) | |
ad7fce93 | 148 | return -1; |
7ba1ba12 MP |
149 | |
150 | if (b1->sector_size != b2->sector_size) { | |
151 | printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__, | |
ad7fce93 | 152 | gd1->disk_name, gd2->disk_name, |
7ba1ba12 MP |
153 | b1->sector_size, b2->sector_size); |
154 | return -1; | |
155 | } | |
156 | ||
157 | if (b1->tuple_size != b2->tuple_size) { | |
158 | printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__, | |
ad7fce93 | 159 | gd1->disk_name, gd2->disk_name, |
7ba1ba12 MP |
160 | b1->tuple_size, b2->tuple_size); |
161 | return -1; | |
162 | } | |
163 | ||
164 | if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) { | |
165 | printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__, | |
ad7fce93 | 166 | gd1->disk_name, gd2->disk_name, |
7ba1ba12 MP |
167 | b1->tag_size, b2->tag_size); |
168 | return -1; | |
169 | } | |
170 | ||
171 | if (strcmp(b1->name, b2->name)) { | |
172 | printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__, | |
ad7fce93 | 173 | gd1->disk_name, gd2->disk_name, |
7ba1ba12 MP |
174 | b1->name, b2->name); |
175 | return -1; | |
176 | } | |
177 | ||
178 | return 0; | |
179 | } | |
180 | EXPORT_SYMBOL(blk_integrity_compare); | |
181 | ||
13f05c8d MP |
182 | int 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 | } | |
194 | EXPORT_SYMBOL(blk_integrity_merge_rq); | |
195 | ||
196 | int 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 | } | |
214 | EXPORT_SYMBOL(blk_integrity_merge_bio); | |
215 | ||
7ba1ba12 MP |
216 | struct integrity_sysfs_entry { |
217 | struct attribute attr; | |
218 | ssize_t (*show)(struct blk_integrity *, char *); | |
219 | ssize_t (*store)(struct blk_integrity *, const char *, size_t); | |
220 | }; | |
221 | ||
222 | static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr, | |
223 | char *page) | |
224 | { | |
225 | struct blk_integrity *bi = | |
226 | container_of(kobj, struct blk_integrity, kobj); | |
227 | struct integrity_sysfs_entry *entry = | |
228 | container_of(attr, struct integrity_sysfs_entry, attr); | |
229 | ||
230 | return entry->show(bi, page); | |
231 | } | |
232 | ||
b984679e JA |
233 | static ssize_t integrity_attr_store(struct kobject *kobj, |
234 | struct attribute *attr, const char *page, | |
235 | size_t count) | |
7ba1ba12 MP |
236 | { |
237 | struct blk_integrity *bi = | |
238 | container_of(kobj, struct blk_integrity, kobj); | |
239 | struct integrity_sysfs_entry *entry = | |
240 | container_of(attr, struct integrity_sysfs_entry, attr); | |
241 | ssize_t ret = 0; | |
242 | ||
243 | if (entry->store) | |
244 | ret = entry->store(bi, page, count); | |
245 | ||
246 | return ret; | |
247 | } | |
248 | ||
249 | static ssize_t integrity_format_show(struct blk_integrity *bi, char *page) | |
250 | { | |
251 | if (bi != NULL && bi->name != NULL) | |
252 | return sprintf(page, "%s\n", bi->name); | |
253 | else | |
254 | return sprintf(page, "none\n"); | |
255 | } | |
256 | ||
257 | static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page) | |
258 | { | |
259 | if (bi != NULL) | |
260 | return sprintf(page, "%u\n", bi->tag_size); | |
261 | else | |
262 | return sprintf(page, "0\n"); | |
263 | } | |
264 | ||
265 | static ssize_t integrity_read_store(struct blk_integrity *bi, | |
266 | const char *page, size_t count) | |
267 | { | |
268 | char *p = (char *) page; | |
269 | unsigned long val = simple_strtoul(p, &p, 10); | |
270 | ||
271 | if (val) | |
b24498d4 | 272 | bi->flags |= INTEGRITY_FLAG_READ; |
7ba1ba12 | 273 | else |
b24498d4 | 274 | bi->flags &= ~INTEGRITY_FLAG_READ; |
7ba1ba12 MP |
275 | |
276 | return count; | |
277 | } | |
278 | ||
279 | static ssize_t integrity_read_show(struct blk_integrity *bi, char *page) | |
280 | { | |
b24498d4 | 281 | return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0); |
7ba1ba12 MP |
282 | } |
283 | ||
284 | static ssize_t integrity_write_store(struct blk_integrity *bi, | |
285 | const char *page, size_t count) | |
286 | { | |
287 | char *p = (char *) page; | |
288 | unsigned long val = simple_strtoul(p, &p, 10); | |
289 | ||
290 | if (val) | |
b24498d4 | 291 | bi->flags |= INTEGRITY_FLAG_WRITE; |
7ba1ba12 | 292 | else |
b24498d4 | 293 | bi->flags &= ~INTEGRITY_FLAG_WRITE; |
7ba1ba12 MP |
294 | |
295 | return count; | |
296 | } | |
297 | ||
298 | static ssize_t integrity_write_show(struct blk_integrity *bi, char *page) | |
299 | { | |
b24498d4 | 300 | return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0); |
7ba1ba12 MP |
301 | } |
302 | ||
303 | static struct integrity_sysfs_entry integrity_format_entry = { | |
304 | .attr = { .name = "format", .mode = S_IRUGO }, | |
305 | .show = integrity_format_show, | |
306 | }; | |
307 | ||
308 | static struct integrity_sysfs_entry integrity_tag_size_entry = { | |
309 | .attr = { .name = "tag_size", .mode = S_IRUGO }, | |
310 | .show = integrity_tag_size_show, | |
311 | }; | |
312 | ||
313 | static struct integrity_sysfs_entry integrity_read_entry = { | |
314 | .attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR }, | |
315 | .show = integrity_read_show, | |
316 | .store = integrity_read_store, | |
317 | }; | |
318 | ||
319 | static struct integrity_sysfs_entry integrity_write_entry = { | |
320 | .attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR }, | |
321 | .show = integrity_write_show, | |
322 | .store = integrity_write_store, | |
323 | }; | |
324 | ||
325 | static struct attribute *integrity_attrs[] = { | |
326 | &integrity_format_entry.attr, | |
327 | &integrity_tag_size_entry.attr, | |
328 | &integrity_read_entry.attr, | |
329 | &integrity_write_entry.attr, | |
330 | NULL, | |
331 | }; | |
332 | ||
52cf25d0 | 333 | static const struct sysfs_ops integrity_ops = { |
7ba1ba12 MP |
334 | .show = &integrity_attr_show, |
335 | .store = &integrity_attr_store, | |
336 | }; | |
337 | ||
338 | static int __init blk_dev_integrity_init(void) | |
339 | { | |
340 | integrity_cachep = kmem_cache_create("blkdev_integrity", | |
341 | sizeof(struct blk_integrity), | |
342 | 0, SLAB_PANIC, NULL); | |
343 | return 0; | |
344 | } | |
345 | subsys_initcall(blk_dev_integrity_init); | |
346 | ||
347 | static void blk_integrity_release(struct kobject *kobj) | |
348 | { | |
349 | struct blk_integrity *bi = | |
350 | container_of(kobj, struct blk_integrity, kobj); | |
351 | ||
352 | kmem_cache_free(integrity_cachep, bi); | |
353 | } | |
354 | ||
355 | static struct kobj_type integrity_ktype = { | |
356 | .default_attrs = integrity_attrs, | |
357 | .sysfs_ops = &integrity_ops, | |
358 | .release = blk_integrity_release, | |
359 | }; | |
360 | ||
361 | /** | |
362 | * blk_integrity_register - Register a gendisk as being integrity-capable | |
363 | * @disk: struct gendisk pointer to make integrity-aware | |
32231638 | 364 | * @template: optional integrity profile to register |
7ba1ba12 MP |
365 | * |
366 | * Description: When a device needs to advertise itself as being able | |
367 | * to send/receive integrity metadata it must use this function to | |
368 | * register the capability with the block layer. The template is a | |
369 | * blk_integrity struct with values appropriate for the underlying | |
32231638 MP |
370 | * hardware. If template is NULL the new profile is allocated but |
371 | * not filled out. See Documentation/block/data-integrity.txt. | |
7ba1ba12 MP |
372 | */ |
373 | int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template) | |
374 | { | |
375 | struct blk_integrity *bi; | |
376 | ||
377 | BUG_ON(disk == NULL); | |
7ba1ba12 MP |
378 | |
379 | if (disk->integrity == NULL) { | |
b984679e | 380 | bi = kmem_cache_alloc(integrity_cachep, |
32231638 | 381 | GFP_KERNEL | __GFP_ZERO); |
7ba1ba12 MP |
382 | if (!bi) |
383 | return -1; | |
384 | ||
385 | if (kobject_init_and_add(&bi->kobj, &integrity_ktype, | |
ed9e1982 TH |
386 | &disk_to_dev(disk)->kobj, |
387 | "%s", "integrity")) { | |
7ba1ba12 MP |
388 | kmem_cache_free(integrity_cachep, bi); |
389 | return -1; | |
390 | } | |
391 | ||
392 | kobject_uevent(&bi->kobj, KOBJ_ADD); | |
393 | ||
b24498d4 | 394 | bi->flags |= INTEGRITY_FLAG_READ | INTEGRITY_FLAG_WRITE; |
e1defc4f | 395 | bi->sector_size = queue_logical_block_size(disk->queue); |
7ba1ba12 MP |
396 | disk->integrity = bi; |
397 | } else | |
398 | bi = disk->integrity; | |
399 | ||
400 | /* Use the provided profile as template */ | |
32231638 MP |
401 | if (template != NULL) { |
402 | bi->name = template->name; | |
403 | bi->generate_fn = template->generate_fn; | |
404 | bi->verify_fn = template->verify_fn; | |
405 | bi->tuple_size = template->tuple_size; | |
406 | bi->set_tag_fn = template->set_tag_fn; | |
407 | bi->get_tag_fn = template->get_tag_fn; | |
408 | bi->tag_size = template->tag_size; | |
409 | } else | |
410 | bi->name = "unsupported"; | |
7ba1ba12 MP |
411 | |
412 | return 0; | |
413 | } | |
414 | EXPORT_SYMBOL(blk_integrity_register); | |
415 | ||
416 | /** | |
417 | * blk_integrity_unregister - Remove block integrity profile | |
418 | * @disk: disk whose integrity profile to deallocate | |
419 | * | |
420 | * Description: This function frees all memory used by the block | |
421 | * integrity profile. To be called at device teardown. | |
422 | */ | |
423 | void blk_integrity_unregister(struct gendisk *disk) | |
424 | { | |
425 | struct blk_integrity *bi; | |
426 | ||
427 | if (!disk || !disk->integrity) | |
428 | return; | |
429 | ||
430 | bi = disk->integrity; | |
431 | ||
432 | kobject_uevent(&bi->kobj, KOBJ_REMOVE); | |
433 | kobject_del(&bi->kobj); | |
3839e4b2 | 434 | kobject_put(&bi->kobj); |
0c032ab8 | 435 | disk->integrity = NULL; |
7ba1ba12 MP |
436 | } |
437 | EXPORT_SYMBOL(blk_integrity_unregister); |