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Source at commit b13e7eb172b6f08e5fc22da162bdde5fcde201b5 created 11 years 11 months ago. By Maarten ter Huurne, fbcon: Add 6x10 font | |
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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/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 | |
32 | static struct kmem_cache *integrity_cachep; |
33 | |
34 | static 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 | */ |
44 | int 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 { |
65 | new_segment: |
66 | segments++; |
67 | seg_size = iv->bv_len; |
68 | } |
69 | |
70 | ivprv = iv; |
71 | } |
72 | |
73 | return segments; |
74 | } |
75 | EXPORT_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 | */ |
87 | int 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 { |
109 | new_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 | } |
129 | EXPORT_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 | */ |
142 | int 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 | } |
183 | EXPORT_SYMBOL(blk_integrity_compare); |
184 | |
185 | int 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 | } |
197 | EXPORT_SYMBOL(blk_integrity_merge_rq); |
198 | |
199 | int 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 | } |
217 | EXPORT_SYMBOL(blk_integrity_merge_bio); |
218 | |
219 | struct 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 | |
225 | static 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 | |
236 | static 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 | |
252 | static 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 | |
260 | static 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 | |
268 | static 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 | |
282 | static 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 | |
287 | static 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 | |
301 | static 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 | |
306 | static struct integrity_sysfs_entry integrity_format_entry = { |
307 | .attr = { .name = "format", .mode = S_IRUGO }, |
308 | .show = integrity_format_show, |
309 | }; |
310 | |
311 | static struct integrity_sysfs_entry integrity_tag_size_entry = { |
312 | .attr = { .name = "tag_size", .mode = S_IRUGO }, |
313 | .show = integrity_tag_size_show, |
314 | }; |
315 | |
316 | static 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 | |
322 | static 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 | |
328 | static 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 | |
336 | static const struct sysfs_ops integrity_ops = { |
337 | .show = &integrity_attr_show, |
338 | .store = &integrity_attr_store, |
339 | }; |
340 | |
341 | static 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 | } |
348 | subsys_initcall(blk_dev_integrity_init); |
349 | |
350 | static 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 | |
358 | static struct kobj_type integrity_ktype = { |
359 | .default_attrs = integrity_attrs, |
360 | .sysfs_ops = &integrity_ops, |
361 | .release = blk_integrity_release, |
362 | }; |
363 | |
364 | bool 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 | } |
370 | EXPORT_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 | */ |
384 | int 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 | } |
425 | EXPORT_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 | */ |
434 | void 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 | } |
448 | EXPORT_SYMBOL(blk_integrity_unregister); |
449 |
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