block/blk-integrity.c

   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);