1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * blk-integrity.c - Block layer data integrity extensions
4  *
5  * Copyright (C) 2007, 2008 Oracle Corporation
6  * Written by: Martin K. Petersen <martin.petersen@oracle.com>
7  */
8 
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>
16 
17 #include "blk.h"
18 
19 /**
20  * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
21  * @q:		request queue
22  * @bio:	bio with integrity metadata attached
23  *
24  * Description: Returns the number of elements required in a
25  * scatterlist corresponding to the integrity metadata in a bio.
26  */
blk_rq_count_integrity_sg(struct request_queue * q,struct bio * bio)27 int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
28 {
29 	struct bio_vec iv, ivprv = { NULL };
30 	unsigned int segments = 0;
31 	unsigned int seg_size = 0;
32 	struct bvec_iter iter;
33 	int prev = 0;
34 
35 	bio_for_each_integrity_vec(iv, bio, iter) {
36 
37 		if (prev) {
38 			if (!biovec_phys_mergeable(q, &ivprv, &iv))
39 				goto new_segment;
40 			if (seg_size + iv.bv_len > queue_max_segment_size(q))
41 				goto new_segment;
42 
43 			seg_size += iv.bv_len;
44 		} else {
45 new_segment:
46 			segments++;
47 			seg_size = iv.bv_len;
48 		}
49 
50 		prev = 1;
51 		ivprv = iv;
52 	}
53 
54 	return segments;
55 }
56 EXPORT_SYMBOL(blk_rq_count_integrity_sg);
57 
58 /**
59  * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
60  * @q:		request queue
61  * @bio:	bio with integrity metadata attached
62  * @sglist:	target scatterlist
63  *
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().
67  */
blk_rq_map_integrity_sg(struct request_queue * q,struct bio * bio,struct scatterlist * sglist)68 int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
69 			    struct scatterlist *sglist)
70 {
71 	struct bio_vec iv, ivprv = { NULL };
72 	struct scatterlist *sg = NULL;
73 	unsigned int segments = 0;
74 	struct bvec_iter iter;
75 	int prev = 0;
76 
77 	bio_for_each_integrity_vec(iv, bio, iter) {
78 
79 		if (prev) {
80 			if (!biovec_phys_mergeable(q, &ivprv, &iv))
81 				goto new_segment;
82 			if (sg->length + iv.bv_len > queue_max_segment_size(q))
83 				goto new_segment;
84 
85 			sg->length += iv.bv_len;
86 		} else {
87 new_segment:
88 			if (!sg)
89 				sg = sglist;
90 			else {
91 				sg_unmark_end(sg);
92 				sg = sg_next(sg);
93 			}
94 
95 			sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
96 			segments++;
97 		}
98 
99 		prev = 1;
100 		ivprv = iv;
101 	}
102 
103 	if (sg)
104 		sg_mark_end(sg);
105 
106 	return segments;
107 }
108 EXPORT_SYMBOL(blk_rq_map_integrity_sg);
109 
110 /**
111  * blk_integrity_compare - Compare integrity profile of two disks
112  * @gd1:	Disk to compare
113  * @gd2:	Disk to compare
114  *
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.
120  */
blk_integrity_compare(struct gendisk * gd1,struct gendisk * gd2)121 int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
122 {
123 	struct blk_integrity *b1 = &gd1->queue->integrity;
124 	struct blk_integrity *b2 = &gd2->queue->integrity;
125 
126 	if (!b1->profile && !b2->profile)
127 		return 0;
128 
129 	if (!b1->profile || !b2->profile)
130 		return -1;
131 
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);
136 		return -1;
137 	}
138 
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);
143 		return -1;
144 	}
145 
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);
150 		return -1;
151 	}
152 
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);
157 		return -1;
158 	}
159 
160 	return 0;
161 }
162 EXPORT_SYMBOL(blk_integrity_compare);
163 
blk_integrity_merge_rq(struct request_queue * q,struct request * req,struct request * next)164 bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
165 			    struct request *next)
166 {
167 	if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
168 		return true;
169 
170 	if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
171 		return false;
172 
173 	if (bio_integrity(req->bio)->bip_flags !=
174 	    bio_integrity(next->bio)->bip_flags)
175 		return false;
176 
177 	if (req->nr_integrity_segments + next->nr_integrity_segments >
178 	    q->limits.max_integrity_segments)
179 		return false;
180 
181 	if (integrity_req_gap_back_merge(req, next->bio))
182 		return false;
183 
184 	return true;
185 }
186 
blk_integrity_merge_bio(struct request_queue * q,struct request * req,struct bio * bio)187 bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
188 			     struct bio *bio)
189 {
190 	int nr_integrity_segs;
191 	struct bio *next = bio->bi_next;
192 
193 	if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
194 		return true;
195 
196 	if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
197 		return false;
198 
199 	if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
200 		return false;
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 false;
209 
210 	req->nr_integrity_segments += nr_integrity_segs;
211 
212 	return true;
213 }
214 
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);
219 };
220 
integrity_attr_show(struct kobject * kobj,struct attribute * attr,char * page)221 static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
222 				   char *page)
223 {
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);
228 
229 	return entry->show(bi, page);
230 }
231 
integrity_attr_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t count)232 static ssize_t integrity_attr_store(struct kobject *kobj,
233 				    struct attribute *attr, const char *page,
234 				    size_t count)
235 {
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);
240 	ssize_t ret = 0;
241 
242 	if (entry->store)
243 		ret = entry->store(bi, page, count);
244 
245 	return ret;
246 }
247 
integrity_format_show(struct blk_integrity * bi,char * page)248 static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
249 {
250 	if (bi->profile && bi->profile->name)
251 		return sprintf(page, "%s\n", bi->profile->name);
252 	else
253 		return sprintf(page, "none\n");
254 }
255 
integrity_tag_size_show(struct blk_integrity * bi,char * page)256 static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
257 {
258 	return sprintf(page, "%u\n", bi->tag_size);
259 }
260 
integrity_interval_show(struct blk_integrity * bi,char * page)261 static ssize_t integrity_interval_show(struct blk_integrity *bi, char *page)
262 {
263 	return sprintf(page, "%u\n",
264 		       bi->interval_exp ? 1 << bi->interval_exp : 0);
265 }
266 
integrity_verify_store(struct blk_integrity * bi,const char * page,size_t count)267 static ssize_t integrity_verify_store(struct blk_integrity *bi,
268 				      const char *page, size_t count)
269 {
270 	char *p = (char *) page;
271 	unsigned long val = simple_strtoul(p, &p, 10);
272 
273 	if (val)
274 		bi->flags |= BLK_INTEGRITY_VERIFY;
275 	else
276 		bi->flags &= ~BLK_INTEGRITY_VERIFY;
277 
278 	return count;
279 }
280 
integrity_verify_show(struct blk_integrity * bi,char * page)281 static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
282 {
283 	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
284 }
285 
integrity_generate_store(struct blk_integrity * bi,const char * page,size_t count)286 static ssize_t integrity_generate_store(struct blk_integrity *bi,
287 					const char *page, size_t count)
288 {
289 	char *p = (char *) page;
290 	unsigned long val = simple_strtoul(p, &p, 10);
291 
292 	if (val)
293 		bi->flags |= BLK_INTEGRITY_GENERATE;
294 	else
295 		bi->flags &= ~BLK_INTEGRITY_GENERATE;
296 
297 	return count;
298 }
299 
integrity_generate_show(struct blk_integrity * bi,char * page)300 static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
301 {
302 	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
303 }
304 
integrity_device_show(struct blk_integrity * bi,char * page)305 static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
306 {
307 	return sprintf(page, "%u\n",
308 		       (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
309 }
310 
311 static struct integrity_sysfs_entry integrity_format_entry = {
312 	.attr = { .name = "format", .mode = 0444 },
313 	.show = integrity_format_show,
314 };
315 
316 static struct integrity_sysfs_entry integrity_tag_size_entry = {
317 	.attr = { .name = "tag_size", .mode = 0444 },
318 	.show = integrity_tag_size_show,
319 };
320 
321 static struct integrity_sysfs_entry integrity_interval_entry = {
322 	.attr = { .name = "protection_interval_bytes", .mode = 0444 },
323 	.show = integrity_interval_show,
324 };
325 
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,
330 };
331 
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,
336 };
337 
338 static struct integrity_sysfs_entry integrity_device_entry = {
339 	.attr = { .name = "device_is_integrity_capable", .mode = 0444 },
340 	.show = integrity_device_show,
341 };
342 
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,
350 	NULL,
351 };
352 ATTRIBUTE_GROUPS(integrity);
353 
354 static const struct sysfs_ops integrity_ops = {
355 	.show	= &integrity_attr_show,
356 	.store	= &integrity_attr_store,
357 };
358 
359 static struct kobj_type integrity_ktype = {
360 	.default_groups = integrity_groups,
361 	.sysfs_ops	= &integrity_ops,
362 };
363 
blk_integrity_nop_fn(struct blk_integrity_iter * iter)364 static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter)
365 {
366 	return BLK_STS_OK;
367 }
368 
blk_integrity_nop_prepare(struct request * rq)369 static void blk_integrity_nop_prepare(struct request *rq)
370 {
371 }
372 
blk_integrity_nop_complete(struct request * rq,unsigned int nr_bytes)373 static void blk_integrity_nop_complete(struct request *rq,
374 		unsigned int nr_bytes)
375 {
376 }
377 
378 static const struct blk_integrity_profile nop_profile = {
379 	.name = "nop",
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,
384 };
385 
386 /**
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
390  *
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.
396  */
blk_integrity_register(struct gendisk * disk,struct blk_integrity * template)397 void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
398 {
399 	struct blk_integrity *bi = &disk->queue->integrity;
400 
401 	bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
402 		template->flags;
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;
408 
409 	blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue);
410 
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);
415 	}
416 #endif
417 }
418 EXPORT_SYMBOL(blk_integrity_register);
419 
420 /**
421  * blk_integrity_unregister - Unregister block integrity profile
422  * @disk:	disk whose integrity profile to unregister
423  *
424  * Description: This function unregisters the integrity capability from
425  * a block device.
426  */
blk_integrity_unregister(struct gendisk * disk)427 void blk_integrity_unregister(struct gendisk *disk)
428 {
429 	struct blk_integrity *bi = &disk->queue->integrity;
430 
431 	if (!bi->profile)
432 		return;
433 
434 	/* ensure all bios are off the integrity workqueue */
435 	blk_flush_integrity();
436 	blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, disk->queue);
437 	memset(bi, 0, sizeof(*bi));
438 }
439 EXPORT_SYMBOL(blk_integrity_unregister);
440 
blk_integrity_add(struct gendisk * disk)441 int blk_integrity_add(struct gendisk *disk)
442 {
443 	int ret;
444 
445 	ret = kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
446 				   &disk_to_dev(disk)->kobj, "%s", "integrity");
447 	if (!ret)
448 		kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
449 	return ret;
450 }
451 
blk_integrity_del(struct gendisk * disk)452 void blk_integrity_del(struct gendisk *disk)
453 {
454 	kobject_uevent(&disk->integrity_kobj, KOBJ_REMOVE);
455 	kobject_del(&disk->integrity_kobj);
456 	kobject_put(&disk->integrity_kobj);
457 }
458