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 */ 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 */ 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 */ 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); 163 164 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 } 186 187 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 static inline struct blk_integrity *dev_to_bi(struct device *dev) 216 { 217 return &dev_to_disk(dev)->queue->integrity; 218 } 219 220 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 } 229 230 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 } 237 238 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 } 247 248 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 } 263 264 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 } 271 272 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 } 288 289 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 } 296 297 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 }; 328 329 static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter) 330 { 331 return BLK_STS_OK; 332 } 333 334 static void blk_integrity_nop_prepare(struct request *rq) 335 { 336 } 337 338 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 */ 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 */ 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 /* ensure all bios are off the integrity workqueue */ 400 blk_flush_integrity(); 401 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, disk->queue); 402 memset(bi, 0, sizeof(*bi)); 403 } 404 EXPORT_SYMBOL(blk_integrity_unregister); 405