LXR linux/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 */
  27int 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 {
  45new_segment:
  46                        segments++;
  47                        seg_size = iv.bv_len;
  48                }
  49
  50                prev = 1;
  51                ivprv = iv;
  52        }
  53
  54        return segments;
  55}
  56EXPORT_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 */
  68int 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 {
  87new_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}
 108EXPORT_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 */
 121int 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}
 162EXPORT_SYMBOL(blk_integrity_compare);
 163
 164bool 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
 187bool 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
 215static inline struct blk_integrity *dev_to_bi(struct device *dev)
 216{
 217        return &dev_to_disk(dev)->queue->integrity;
 218}
 219
 220static 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
 230static 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
 238static 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
 248static 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
 264static 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
 272static 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
 289static 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
 297static 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
 307static DEVICE_ATTR_RO(format);
 308static DEVICE_ATTR_RO(tag_size);
 309static DEVICE_ATTR_RO(protection_interval_bytes);
 310static DEVICE_ATTR_RW(read_verify);
 311static DEVICE_ATTR_RW(write_generate);
 312static DEVICE_ATTR_RO(device_is_integrity_capable);
 313
 314static 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
 324const struct attribute_group blk_integrity_attr_group = {
 325        .name = "integrity",
 326        .attrs = integrity_attrs,
 327};
 328
 329static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter)
 330{
 331        return BLK_STS_OK;
 332}
 333
 334static void blk_integrity_nop_prepare(struct request *rq)
 335{
 336}
 337
 338static void blk_integrity_nop_complete(struct request *rq,
 339                unsigned int nr_bytes)
 340{
 341}
 342
 343static 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 */
 362void 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}
 383EXPORT_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 */
 392void 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}
 404EXPORT_SYMBOL(blk_integrity_unregister);
 405