1 // SPDX-License-Identifier: GPL-2.0
3 * blk-integrity.c - Block layer data integrity extensions
5 * Copyright (C) 2007, 2008 Oracle Corporation
6 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
9 #include <linux/blkdev.h>
10 #include <linux/backing-dev.h>
11 #include <linux/mempool.h>
12 #include <linux/bio.h>
13 #include <linux/scatterlist.h>
14 #include <linux/export.h>
15 #include <linux/slab.h>
20 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
22 * @bio: bio with integrity metadata attached
24 * Description: Returns the number of elements required in a
25 * scatterlist corresponding to the integrity metadata in a bio.
27 int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
29 struct bio_vec iv, ivprv = { NULL };
30 unsigned int segments = 0;
31 unsigned int seg_size = 0;
32 struct bvec_iter iter;
35 bio_for_each_integrity_vec(iv, bio, iter) {
38 if (!biovec_phys_mergeable(q, &ivprv, &iv))
40 if (seg_size + iv.bv_len > queue_max_segment_size(q))
43 seg_size += iv.bv_len;
56 EXPORT_SYMBOL(blk_rq_count_integrity_sg);
59 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
61 * @bio: bio with integrity metadata attached
62 * @sglist: target scatterlist
64 * Description: Map the integrity vectors in request into a
65 * scatterlist. The scatterlist must be big enough to hold all
66 * elements. I.e. sized using blk_rq_count_integrity_sg().
68 int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
69 struct scatterlist *sglist)
71 struct bio_vec iv, ivprv = { NULL };
72 struct scatterlist *sg = NULL;
73 unsigned int segments = 0;
74 struct bvec_iter iter;
77 bio_for_each_integrity_vec(iv, bio, iter) {
80 if (!biovec_phys_mergeable(q, &ivprv, &iv))
82 if (sg->length + iv.bv_len > queue_max_segment_size(q))
85 sg->length += iv.bv_len;
95 sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
108 EXPORT_SYMBOL(blk_rq_map_integrity_sg);
111 * blk_integrity_compare - Compare integrity profile of two disks
112 * @gd1: Disk to compare
113 * @gd2: Disk to compare
115 * Description: Meta-devices like DM and MD need to verify that all
116 * sub-devices use the same integrity format before advertising to
117 * upper layers that they can send/receive integrity metadata. This
118 * function can be used to check whether two gendisk devices have
119 * compatible integrity formats.
121 int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
123 struct blk_integrity *b1 = &gd1->queue->integrity;
124 struct blk_integrity *b2 = &gd2->queue->integrity;
126 if (!b1->profile && !b2->profile)
129 if (!b1->profile || !b2->profile)
132 if (b1->interval_exp != b2->interval_exp) {
133 pr_err("%s: %s/%s protection interval %u != %u\n",
134 __func__, gd1->disk_name, gd2->disk_name,
135 1 << b1->interval_exp, 1 << b2->interval_exp);
139 if (b1->tuple_size != b2->tuple_size) {
140 pr_err("%s: %s/%s tuple sz %u != %u\n", __func__,
141 gd1->disk_name, gd2->disk_name,
142 b1->tuple_size, b2->tuple_size);
146 if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
147 pr_err("%s: %s/%s tag sz %u != %u\n", __func__,
148 gd1->disk_name, gd2->disk_name,
149 b1->tag_size, b2->tag_size);
153 if (b1->profile != b2->profile) {
154 pr_err("%s: %s/%s type %s != %s\n", __func__,
155 gd1->disk_name, gd2->disk_name,
156 b1->profile->name, b2->profile->name);
162 EXPORT_SYMBOL(blk_integrity_compare);
164 bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
165 struct request *next)
167 if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
170 if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
173 if (bio_integrity(req->bio)->bip_flags !=
174 bio_integrity(next->bio)->bip_flags)
177 if (req->nr_integrity_segments + next->nr_integrity_segments >
178 q->limits.max_integrity_segments)
181 if (integrity_req_gap_back_merge(req, next->bio))
187 bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
190 int nr_integrity_segs;
191 struct bio *next = bio->bi_next;
193 if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
196 if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
199 if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
203 nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
206 if (req->nr_integrity_segments + nr_integrity_segs >
207 q->limits.max_integrity_segments)
210 req->nr_integrity_segments += nr_integrity_segs;
215 struct integrity_sysfs_entry {
216 struct attribute attr;
217 ssize_t (*show)(struct blk_integrity *, char *);
218 ssize_t (*store)(struct blk_integrity *, const char *, size_t);
221 static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
224 struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
225 struct blk_integrity *bi = &disk->queue->integrity;
226 struct integrity_sysfs_entry *entry =
227 container_of(attr, struct integrity_sysfs_entry, attr);
229 return entry->show(bi, page);
232 static ssize_t integrity_attr_store(struct kobject *kobj,
233 struct attribute *attr, const char *page,
236 struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
237 struct blk_integrity *bi = &disk->queue->integrity;
238 struct integrity_sysfs_entry *entry =
239 container_of(attr, struct integrity_sysfs_entry, attr);
243 ret = entry->store(bi, page, count);
248 static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
250 if (bi->profile && bi->profile->name)
251 return sprintf(page, "%s\n", bi->profile->name);
253 return sprintf(page, "none\n");
256 static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
258 return sprintf(page, "%u\n", bi->tag_size);
261 static ssize_t integrity_interval_show(struct blk_integrity *bi, char *page)
263 return sprintf(page, "%u\n",
264 bi->interval_exp ? 1 << bi->interval_exp : 0);
267 static ssize_t integrity_verify_store(struct blk_integrity *bi,
268 const char *page, size_t count)
270 char *p = (char *) page;
271 unsigned long val = simple_strtoul(p, &p, 10);
274 bi->flags |= BLK_INTEGRITY_VERIFY;
276 bi->flags &= ~BLK_INTEGRITY_VERIFY;
281 static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
283 return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
286 static ssize_t integrity_generate_store(struct blk_integrity *bi,
287 const char *page, size_t count)
289 char *p = (char *) page;
290 unsigned long val = simple_strtoul(p, &p, 10);
293 bi->flags |= BLK_INTEGRITY_GENERATE;
295 bi->flags &= ~BLK_INTEGRITY_GENERATE;
300 static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
302 return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
305 static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
307 return sprintf(page, "%u\n",
308 (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
311 static struct integrity_sysfs_entry integrity_format_entry = {
312 .attr = { .name = "format", .mode = 0444 },
313 .show = integrity_format_show,
316 static struct integrity_sysfs_entry integrity_tag_size_entry = {
317 .attr = { .name = "tag_size", .mode = 0444 },
318 .show = integrity_tag_size_show,
321 static struct integrity_sysfs_entry integrity_interval_entry = {
322 .attr = { .name = "protection_interval_bytes", .mode = 0444 },
323 .show = integrity_interval_show,
326 static struct integrity_sysfs_entry integrity_verify_entry = {
327 .attr = { .name = "read_verify", .mode = 0644 },
328 .show = integrity_verify_show,
329 .store = integrity_verify_store,
332 static struct integrity_sysfs_entry integrity_generate_entry = {
333 .attr = { .name = "write_generate", .mode = 0644 },
334 .show = integrity_generate_show,
335 .store = integrity_generate_store,
338 static struct integrity_sysfs_entry integrity_device_entry = {
339 .attr = { .name = "device_is_integrity_capable", .mode = 0444 },
340 .show = integrity_device_show,
343 static struct attribute *integrity_attrs[] = {
344 &integrity_format_entry.attr,
345 &integrity_tag_size_entry.attr,
346 &integrity_interval_entry.attr,
347 &integrity_verify_entry.attr,
348 &integrity_generate_entry.attr,
349 &integrity_device_entry.attr,
352 ATTRIBUTE_GROUPS(integrity);
354 static const struct sysfs_ops integrity_ops = {
355 .show = &integrity_attr_show,
356 .store = &integrity_attr_store,
359 static struct kobj_type integrity_ktype = {
360 .default_groups = integrity_groups,
361 .sysfs_ops = &integrity_ops,
364 static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter)
369 static void blk_integrity_nop_prepare(struct request *rq)
373 static void blk_integrity_nop_complete(struct request *rq,
374 unsigned int nr_bytes)
378 static const struct blk_integrity_profile nop_profile = {
380 .generate_fn = blk_integrity_nop_fn,
381 .verify_fn = blk_integrity_nop_fn,
382 .prepare_fn = blk_integrity_nop_prepare,
383 .complete_fn = blk_integrity_nop_complete,
387 * blk_integrity_register - Register a gendisk as being integrity-capable
388 * @disk: struct gendisk pointer to make integrity-aware
389 * @template: block integrity profile to register
391 * Description: When a device needs to advertise itself as being able to
392 * send/receive integrity metadata it must use this function to register
393 * the capability with the block layer. The template is a blk_integrity
394 * struct with values appropriate for the underlying hardware. See
395 * Documentation/block/data-integrity.rst.
397 void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
399 struct blk_integrity *bi = &disk->queue->integrity;
401 bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
403 bi->interval_exp = template->interval_exp ? :
404 ilog2(queue_logical_block_size(disk->queue));
405 bi->profile = template->profile ? template->profile : &nop_profile;
406 bi->tuple_size = template->tuple_size;
407 bi->tag_size = template->tag_size;
409 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue);
411 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
412 if (disk->queue->ksm) {
413 pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together. Disabling hardware inline encryption.\n");
414 blk_ksm_unregister(disk->queue);
418 EXPORT_SYMBOL(blk_integrity_register);
421 * blk_integrity_unregister - Unregister block integrity profile
422 * @disk: disk whose integrity profile to unregister
424 * Description: This function unregisters the integrity capability from
427 void blk_integrity_unregister(struct gendisk *disk)
429 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, disk->queue);
430 memset(&disk->queue->integrity, 0, sizeof(struct blk_integrity));
432 EXPORT_SYMBOL(blk_integrity_unregister);
434 void blk_integrity_add(struct gendisk *disk)
436 if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
437 &disk_to_dev(disk)->kobj, "%s", "integrity"))
440 kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
443 void blk_integrity_del(struct gendisk *disk)
445 kobject_uevent(&disk->integrity_kobj, KOBJ_REMOVE);
446 kobject_del(&disk->integrity_kobj);
447 kobject_put(&disk->integrity_kobj);