blob: 03cf7179e8ef1aac2f1698eae57377e65a94f275 [file] [log] [blame]
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001/*
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>
Paul Gortmakerd5decd32011-05-26 16:00:52 -040027#include <linux/export.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020029
30#include "blk.h"
31
32static struct kmem_cache *integrity_cachep;
33
Mike Snitzera63a5cf2011-04-01 21:02:31 +020034static const char *bi_unsupported_name = "unsupported";
35
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020036/**
37 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
Martin K. Petersen13f05c82010-09-10 20:50:10 +020038 * @q: request queue
39 * @bio: bio with integrity metadata attached
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020040 *
41 * Description: Returns the number of elements required in a
Martin K. Petersen13f05c82010-09-10 20:50:10 +020042 * scatterlist corresponding to the integrity metadata in a bio.
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020043 */
Martin K. Petersen13f05c82010-09-10 20:50:10 +020044int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020045{
Martin K. Petersen13f05c82010-09-10 20:50:10 +020046 struct bio_vec *iv, *ivprv = NULL;
47 unsigned int segments = 0;
48 unsigned int seg_size = 0;
49 unsigned int i = 0;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020050
Martin K. Petersen13f05c82010-09-10 20:50:10 +020051 bio_for_each_integrity_vec(iv, bio, i) {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020052
Martin K. Petersen13f05c82010-09-10 20:50:10 +020053 if (ivprv) {
54 if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
55 goto new_segment;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020056
Martin K. Petersen13f05c82010-09-10 20:50:10 +020057 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:
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020066 segments++;
Martin K. Petersen13f05c82010-09-10 20:50:10 +020067 seg_size = iv->bv_len;
68 }
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020069
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
Martin K. Petersen13f05c82010-09-10 20:50:10 +020079 * @q: request queue
80 * @bio: bio with integrity metadata attached
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020081 * @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 */
Martin K. Petersen13f05c82010-09-10 20:50:10 +020087int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
88 struct scatterlist *sglist)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020089{
Martin K. Petersen13f05c82010-09-10 20:50:10 +020090 struct bio_vec *iv, *ivprv = NULL;
91 struct scatterlist *sg = NULL;
92 unsigned int segments = 0;
93 unsigned int i = 0;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020094
Martin K. Petersen13f05c82010-09-10 20:50:10 +020095 bio_for_each_integrity_vec(iv, bio, i) {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020096
97 if (ivprv) {
98 if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
99 goto new_segment;
100
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200101 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
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200107 sg->length += iv->bv_len;
108 } else {
109new_segment:
110 if (!sg)
111 sg = sglist;
112 else {
Paolo Bonzinic8164d82013-03-20 15:37:08 +1030113 sg_unmark_end(sg);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200114 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/**
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400132 * blk_integrity_compare - Compare integrity profile of two disks
133 * @gd1: Disk to compare
134 * @gd2: Disk to compare
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200135 *
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
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400139 * function can be used to check whether two gendisk devices have
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200140 * compatible integrity formats.
141 */
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400142int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200143{
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400144 struct blk_integrity *b1 = gd1->integrity;
145 struct blk_integrity *b2 = gd2->integrity;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200146
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400147 if (!b1 && !b2)
148 return 0;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200149
150 if (!b1 || !b2)
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400151 return -1;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200152
153 if (b1->sector_size != b2->sector_size) {
154 printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400155 gd1->disk_name, gd2->disk_name,
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200156 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__,
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400162 gd1->disk_name, gd2->disk_name,
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200163 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__,
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400169 gd1->disk_name, gd2->disk_name,
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200170 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__,
Martin K. Petersenad7fce92008-10-01 03:38:39 -0400176 gd1->disk_name, gd2->disk_name,
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200177 b1->name, b2->name);
178 return -1;
179 }
180
181 return 0;
182}
183EXPORT_SYMBOL(blk_integrity_compare);
184
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200185int 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
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200219struct 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
Jens Axboeb9846792008-06-17 19:05:48 +0200236static ssize_t integrity_attr_store(struct kobject *kobj,
237 struct attribute *attr, const char *page,
238 size_t count)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200239{
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)
Jens Axboeb24498d2008-06-27 09:12:09 +0200275 bi->flags |= INTEGRITY_FLAG_READ;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200276 else
Jens Axboeb24498d2008-06-27 09:12:09 +0200277 bi->flags &= ~INTEGRITY_FLAG_READ;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200278
279 return count;
280}
281
282static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
283{
Jens Axboeb24498d2008-06-27 09:12:09 +0200284 return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200285}
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)
Jens Axboeb24498d2008-06-27 09:12:09 +0200294 bi->flags |= INTEGRITY_FLAG_WRITE;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200295 else
Jens Axboeb24498d2008-06-27 09:12:09 +0200296 bi->flags &= ~INTEGRITY_FLAG_WRITE;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200297
298 return count;
299}
300
301static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
302{
Jens Axboeb24498d2008-06-27 09:12:09 +0200303 return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200304}
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
Emese Revfy52cf25d2010-01-19 02:58:23 +0100336static const struct sysfs_ops integrity_ops = {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200337 .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
Mike Snitzera63a5cf2011-04-01 21:02:31 +0200364bool 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
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200372/**
373 * blk_integrity_register - Register a gendisk as being integrity-capable
374 * @disk: struct gendisk pointer to make integrity-aware
Martin K. Petersen32231632009-01-04 02:43:40 -0500375 * @template: optional integrity profile to register
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200376 *
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
Martin K. Petersen32231632009-01-04 02:43:40 -0500381 * hardware. If template is NULL the new profile is allocated but
382 * not filled out. See Documentation/block/data-integrity.txt.
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200383 */
384int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
385{
386 struct blk_integrity *bi;
387
388 BUG_ON(disk == NULL);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200389
390 if (disk->integrity == NULL) {
Jens Axboeb9846792008-06-17 19:05:48 +0200391 bi = kmem_cache_alloc(integrity_cachep,
Martin K. Petersen32231632009-01-04 02:43:40 -0500392 GFP_KERNEL | __GFP_ZERO);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200393 if (!bi)
394 return -1;
395
396 if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
Tejun Heoed9e1982008-08-25 19:56:05 +0900397 &disk_to_dev(disk)->kobj,
398 "%s", "integrity")) {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200399 kmem_cache_free(integrity_cachep, bi);
400 return -1;
401 }
402
403 kobject_uevent(&bi->kobj, KOBJ_ADD);
404
Jens Axboeb24498d2008-06-27 09:12:09 +0200405 bi->flags |= INTEGRITY_FLAG_READ | INTEGRITY_FLAG_WRITE;
Martin K. Petersene1defc42009-05-22 17:17:49 -0400406 bi->sector_size = queue_logical_block_size(disk->queue);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200407 disk->integrity = bi;
408 } else
409 bi = disk->integrity;
410
411 /* Use the provided profile as template */
Martin K. Petersen32231632009-01-04 02:43:40 -0500412 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
Mike Snitzera63a5cf2011-04-01 21:02:31 +0200421 bi->name = bi_unsupported_name;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200422
Darrick J. Wong7d311cd2013-02-21 16:42:48 -0800423 disk->queue->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;
424
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200425 return 0;
426}
427EXPORT_SYMBOL(blk_integrity_register);
428
429/**
430 * blk_integrity_unregister - Remove block integrity profile
431 * @disk: disk whose integrity profile to deallocate
432 *
433 * Description: This function frees all memory used by the block
434 * integrity profile. To be called at device teardown.
435 */
436void blk_integrity_unregister(struct gendisk *disk)
437{
438 struct blk_integrity *bi;
439
440 if (!disk || !disk->integrity)
441 return;
442
Darrick J. Wong7d311cd2013-02-21 16:42:48 -0800443 disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;
444
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200445 bi = disk->integrity;
446
447 kobject_uevent(&bi->kobj, KOBJ_REMOVE);
448 kobject_del(&bi->kobj);
Xiaotian Feng3839e4b2009-07-28 09:11:14 +0200449 kobject_put(&bi->kobj);
Martin K. Petersen0c032ab2008-10-01 03:38:38 -0400450 disk->integrity = NULL;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200451}
452EXPORT_SYMBOL(blk_integrity_unregister);