xref: /openbmc/linux/block/blk-integrity.c (revision 2e91ea29)
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/blk-integrity.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 
dev_to_bi(struct device * dev)215 static inline struct blk_integrity *dev_to_bi(struct device *dev)
216 {
217 	return &dev_to_disk(dev)->queue->integrity;
218 }
219 
format_show(struct device * dev,struct device_attribute * attr,char * page)220 static ssize_t format_show(struct device *dev, struct device_attribute *attr,
221 			   char *page)
222 {
223 	struct blk_integrity *bi = dev_to_bi(dev);
224 
225 	if (bi->profile && bi->profile->name)
226 		return sysfs_emit(page, "%s\n", bi->profile->name);
227 	return sysfs_emit(page, "none\n");
228 }
229 
tag_size_show(struct device * dev,struct device_attribute * attr,char * page)230 static ssize_t tag_size_show(struct device *dev, struct device_attribute *attr,
231 			     char *page)
232 {
233 	struct blk_integrity *bi = dev_to_bi(dev);
234 
235 	return sysfs_emit(page, "%u\n", bi->tag_size);
236 }
237 
protection_interval_bytes_show(struct device * dev,struct device_attribute * attr,char * page)238 static ssize_t protection_interval_bytes_show(struct device *dev,
239 					      struct device_attribute *attr,
240 					      char *page)
241 {
242 	struct blk_integrity *bi = dev_to_bi(dev);
243 
244 	return sysfs_emit(page, "%u\n",
245 			  bi->interval_exp ? 1 << bi->interval_exp : 0);
246 }
247 
read_verify_store(struct device * dev,struct device_attribute * attr,const char * page,size_t count)248 static ssize_t read_verify_store(struct device *dev,
249 				 struct device_attribute *attr,
250 				 const char *page, size_t count)
251 {
252 	struct blk_integrity *bi = dev_to_bi(dev);
253 	char *p = (char *) page;
254 	unsigned long val = simple_strtoul(p, &p, 10);
255 
256 	if (val)
257 		bi->flags |= BLK_INTEGRITY_VERIFY;
258 	else
259 		bi->flags &= ~BLK_INTEGRITY_VERIFY;
260 
261 	return count;
262 }
263 
read_verify_show(struct device * dev,struct device_attribute * attr,char * page)264 static ssize_t read_verify_show(struct device *dev,
265 				struct device_attribute *attr, char *page)
266 {
267 	struct blk_integrity *bi = dev_to_bi(dev);
268 
269 	return sysfs_emit(page, "%d\n", !!(bi->flags & BLK_INTEGRITY_VERIFY));
270 }
271 
write_generate_store(struct device * dev,struct device_attribute * attr,const char * page,size_t count)272 static ssize_t write_generate_store(struct device *dev,
273 				    struct device_attribute *attr,
274 				    const char *page, size_t count)
275 {
276 	struct blk_integrity *bi = dev_to_bi(dev);
277 
278 	char *p = (char *) page;
279 	unsigned long val = simple_strtoul(p, &p, 10);
280 
281 	if (val)
282 		bi->flags |= BLK_INTEGRITY_GENERATE;
283 	else
284 		bi->flags &= ~BLK_INTEGRITY_GENERATE;
285 
286 	return count;
287 }
288 
write_generate_show(struct device * dev,struct device_attribute * attr,char * page)289 static ssize_t write_generate_show(struct device *dev,
290 				   struct device_attribute *attr, char *page)
291 {
292 	struct blk_integrity *bi = dev_to_bi(dev);
293 
294 	return sysfs_emit(page, "%d\n", !!(bi->flags & BLK_INTEGRITY_GENERATE));
295 }
296 
device_is_integrity_capable_show(struct device * dev,struct device_attribute * attr,char * page)297 static ssize_t device_is_integrity_capable_show(struct device *dev,
298 						struct device_attribute *attr,
299 						char *page)
300 {
301 	struct blk_integrity *bi = dev_to_bi(dev);
302 
303 	return sysfs_emit(page, "%u\n",
304 			  !!(bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE));
305 }
306 
307 static DEVICE_ATTR_RO(format);
308 static DEVICE_ATTR_RO(tag_size);
309 static DEVICE_ATTR_RO(protection_interval_bytes);
310 static DEVICE_ATTR_RW(read_verify);
311 static DEVICE_ATTR_RW(write_generate);
312 static DEVICE_ATTR_RO(device_is_integrity_capable);
313 
314 static struct attribute *integrity_attrs[] = {
315 	&dev_attr_format.attr,
316 	&dev_attr_tag_size.attr,
317 	&dev_attr_protection_interval_bytes.attr,
318 	&dev_attr_read_verify.attr,
319 	&dev_attr_write_generate.attr,
320 	&dev_attr_device_is_integrity_capable.attr,
321 	NULL
322 };
323 
324 const struct attribute_group blk_integrity_attr_group = {
325 	.name = "integrity",
326 	.attrs = integrity_attrs,
327 };
328 
blk_integrity_nop_fn(struct blk_integrity_iter * iter)329 static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter)
330 {
331 	return BLK_STS_OK;
332 }
333 
blk_integrity_nop_prepare(struct request * rq)334 static void blk_integrity_nop_prepare(struct request *rq)
335 {
336 }
337 
blk_integrity_nop_complete(struct request * rq,unsigned int nr_bytes)338 static void blk_integrity_nop_complete(struct request *rq,
339 		unsigned int nr_bytes)
340 {
341 }
342 
343 static const struct blk_integrity_profile nop_profile = {
344 	.name = "nop",
345 	.generate_fn = blk_integrity_nop_fn,
346 	.verify_fn = blk_integrity_nop_fn,
347 	.prepare_fn = blk_integrity_nop_prepare,
348 	.complete_fn = blk_integrity_nop_complete,
349 };
350 
351 /**
352  * blk_integrity_register - Register a gendisk as being integrity-capable
353  * @disk:	struct gendisk pointer to make integrity-aware
354  * @template:	block integrity profile to register
355  *
356  * Description: When a device needs to advertise itself as being able to
357  * send/receive integrity metadata it must use this function to register
358  * the capability with the block layer. The template is a blk_integrity
359  * struct with values appropriate for the underlying hardware. See
360  * Documentation/block/data-integrity.rst.
361  */
blk_integrity_register(struct gendisk * disk,struct blk_integrity * template)362 void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
363 {
364 	struct blk_integrity *bi = &disk->queue->integrity;
365 
366 	bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
367 		template->flags;
368 	bi->interval_exp = template->interval_exp ? :
369 		ilog2(queue_logical_block_size(disk->queue));
370 	bi->profile = template->profile ? template->profile : &nop_profile;
371 	bi->tuple_size = template->tuple_size;
372 	bi->tag_size = template->tag_size;
373 
374 	blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue);
375 
376 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
377 	if (disk->queue->crypto_profile) {
378 		pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together. Disabling hardware inline encryption.\n");
379 		disk->queue->crypto_profile = NULL;
380 	}
381 #endif
382 }
383 EXPORT_SYMBOL(blk_integrity_register);
384 
385 /**
386  * blk_integrity_unregister - Unregister block integrity profile
387  * @disk:	disk whose integrity profile to unregister
388  *
389  * Description: This function unregisters the integrity capability from
390  * a block device.
391  */
blk_integrity_unregister(struct gendisk * disk)392 void blk_integrity_unregister(struct gendisk *disk)
393 {
394 	struct blk_integrity *bi = &disk->queue->integrity;
395 
396 	if (!bi->profile)
397 		return;
398 
399 	blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, disk->queue);
400 	memset(bi, 0, sizeof(*bi));
401 }
402 EXPORT_SYMBOL(blk_integrity_unregister);
403