linux/fs/bio-integrity.c
<<
>>
Prefs
   1/*
   2 * bio-integrity.c - bio data integrity extensions
   3 *
   4 * Copyright (C) 2007, 2008, 2009 Oracle Corporation
   5 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License version
   9 * 2 as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; see the file COPYING.  If not, write to
  18 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
  19 * USA.
  20 *
  21 */
  22
  23#include <linux/blkdev.h>
  24#include <linux/mempool.h>
  25#include <linux/bio.h>
  26#include <linux/workqueue.h>
  27#include <linux/slab.h>
  28
  29struct integrity_slab {
  30        struct kmem_cache *slab;
  31        unsigned short nr_vecs;
  32        char name[8];
  33};
  34
  35#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) }
  36struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = {
  37        IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES),
  38};
  39#undef IS
  40
  41static struct workqueue_struct *kintegrityd_wq;
  42
  43static inline unsigned int vecs_to_idx(unsigned int nr)
  44{
  45        switch (nr) {
  46        case 1:
  47                return 0;
  48        case 2 ... 4:
  49                return 1;
  50        case 5 ... 16:
  51                return 2;
  52        case 17 ... 64:
  53                return 3;
  54        case 65 ... 128:
  55                return 4;
  56        case 129 ... BIO_MAX_PAGES:
  57                return 5;
  58        default:
  59                BUG();
  60        }
  61}
  62
  63static inline int use_bip_pool(unsigned int idx)
  64{
  65        if (idx == BIOVEC_MAX_IDX)
  66                return 1;
  67
  68        return 0;
  69}
  70
  71/**
  72 * bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
  73 * @bio:        bio to attach integrity metadata to
  74 * @gfp_mask:   Memory allocation mask
  75 * @nr_vecs:    Number of integrity metadata scatter-gather elements
  76 * @bs:         bio_set to allocate from
  77 *
  78 * Description: This function prepares a bio for attaching integrity
  79 * metadata.  nr_vecs specifies the maximum number of pages containing
  80 * integrity metadata that can be attached.
  81 */
  82struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
  83                                                         gfp_t gfp_mask,
  84                                                         unsigned int nr_vecs,
  85                                                         struct bio_set *bs)
  86{
  87        struct bio_integrity_payload *bip;
  88        unsigned int idx = vecs_to_idx(nr_vecs);
  89
  90        BUG_ON(bio == NULL);
  91        bip = NULL;
  92
  93        /* Lower order allocations come straight from slab */
  94        if (!use_bip_pool(idx))
  95                bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);
  96
  97        /* Use mempool if lower order alloc failed or max vecs were requested */
  98        if (bip == NULL) {
  99                idx = BIOVEC_MAX_IDX;  /* so we free the payload properly later */
 100                bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
 101
 102                if (unlikely(bip == NULL)) {
 103                        printk(KERN_ERR "%s: could not alloc bip\n", __func__);
 104                        return NULL;
 105                }
 106        }
 107
 108        memset(bip, 0, sizeof(*bip));
 109
 110        bip->bip_slab = idx;
 111        bip->bip_bio = bio;
 112        bio->bi_integrity = bip;
 113
 114        return bip;
 115}
 116EXPORT_SYMBOL(bio_integrity_alloc_bioset);
 117
 118/**
 119 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
 120 * @bio:        bio to attach integrity metadata to
 121 * @gfp_mask:   Memory allocation mask
 122 * @nr_vecs:    Number of integrity metadata scatter-gather elements
 123 *
 124 * Description: This function prepares a bio for attaching integrity
 125 * metadata.  nr_vecs specifies the maximum number of pages containing
 126 * integrity metadata that can be attached.
 127 */
 128struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
 129                                                  gfp_t gfp_mask,
 130                                                  unsigned int nr_vecs)
 131{
 132        return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
 133}
 134EXPORT_SYMBOL(bio_integrity_alloc);
 135
 136/**
 137 * bio_integrity_free - Free bio integrity payload
 138 * @bio:        bio containing bip to be freed
 139 * @bs:         bio_set this bio was allocated from
 140 *
 141 * Description: Used to free the integrity portion of a bio. Usually
 142 * called from bio_free().
 143 */
 144void bio_integrity_free(struct bio *bio, struct bio_set *bs)
 145{
 146        struct bio_integrity_payload *bip = bio->bi_integrity;
 147
 148        BUG_ON(bip == NULL);
 149
 150        /* A cloned bio doesn't own the integrity metadata */
 151        if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
 152            && bip->bip_buf != NULL)
 153                kfree(bip->bip_buf);
 154
 155        if (use_bip_pool(bip->bip_slab))
 156                mempool_free(bip, bs->bio_integrity_pool);
 157        else
 158                kmem_cache_free(bip_slab[bip->bip_slab].slab, bip);
 159
 160        bio->bi_integrity = NULL;
 161}
 162EXPORT_SYMBOL(bio_integrity_free);
 163
 164/**
 165 * bio_integrity_add_page - Attach integrity metadata
 166 * @bio:        bio to update
 167 * @page:       page containing integrity metadata
 168 * @len:        number of bytes of integrity metadata in page
 169 * @offset:     start offset within page
 170 *
 171 * Description: Attach a page containing integrity metadata to bio.
 172 */
 173int bio_integrity_add_page(struct bio *bio, struct page *page,
 174                           unsigned int len, unsigned int offset)
 175{
 176        struct bio_integrity_payload *bip = bio->bi_integrity;
 177        struct bio_vec *iv;
 178
 179        if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_slab)) {
 180                printk(KERN_ERR "%s: bip_vec full\n", __func__);
 181                return 0;
 182        }
 183
 184        iv = bip_vec_idx(bip, bip->bip_vcnt);
 185        BUG_ON(iv == NULL);
 186
 187        iv->bv_page = page;
 188        iv->bv_len = len;
 189        iv->bv_offset = offset;
 190        bip->bip_vcnt++;
 191
 192        return len;
 193}
 194EXPORT_SYMBOL(bio_integrity_add_page);
 195
 196static int bdev_integrity_enabled(struct block_device *bdev, int rw)
 197{
 198        struct blk_integrity *bi = bdev_get_integrity(bdev);
 199
 200        if (bi == NULL)
 201                return 0;
 202
 203        if (rw == READ && bi->verify_fn != NULL &&
 204            (bi->flags & INTEGRITY_FLAG_READ))
 205                return 1;
 206
 207        if (rw == WRITE && bi->generate_fn != NULL &&
 208            (bi->flags & INTEGRITY_FLAG_WRITE))
 209                return 1;
 210
 211        return 0;
 212}
 213
 214/**
 215 * bio_integrity_enabled - Check whether integrity can be passed
 216 * @bio:        bio to check
 217 *
 218 * Description: Determines whether bio_integrity_prep() can be called
 219 * on this bio or not.  bio data direction and target device must be
 220 * set prior to calling.  The functions honors the write_generate and
 221 * read_verify flags in sysfs.
 222 */
 223int bio_integrity_enabled(struct bio *bio)
 224{
 225        /* Already protected? */
 226        if (bio_integrity(bio))
 227                return 0;
 228
 229        return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
 230}
 231EXPORT_SYMBOL(bio_integrity_enabled);
 232
 233/**
 234 * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
 235 * @bi:         blk_integrity profile for device
 236 * @sectors:    Number of 512 sectors to convert
 237 *
 238 * Description: The block layer calculates everything in 512 byte
 239 * sectors but integrity metadata is done in terms of the hardware
 240 * sector size of the storage device.  Convert the block layer sectors
 241 * to physical sectors.
 242 */
 243static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
 244                                                    unsigned int sectors)
 245{
 246        /* At this point there are only 512b or 4096b DIF/EPP devices */
 247        if (bi->sector_size == 4096)
 248                return sectors >>= 3;
 249
 250        return sectors;
 251}
 252
 253/**
 254 * bio_integrity_tag_size - Retrieve integrity tag space
 255 * @bio:        bio to inspect
 256 *
 257 * Description: Returns the maximum number of tag bytes that can be
 258 * attached to this bio. Filesystems can use this to determine how
 259 * much metadata to attach to an I/O.
 260 */
 261unsigned int bio_integrity_tag_size(struct bio *bio)
 262{
 263        struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 264
 265        BUG_ON(bio->bi_size == 0);
 266
 267        return bi->tag_size * (bio->bi_size / bi->sector_size);
 268}
 269EXPORT_SYMBOL(bio_integrity_tag_size);
 270
 271int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
 272{
 273        struct bio_integrity_payload *bip = bio->bi_integrity;
 274        struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 275        unsigned int nr_sectors;
 276
 277        BUG_ON(bip->bip_buf == NULL);
 278
 279        if (bi->tag_size == 0)
 280                return -1;
 281
 282        nr_sectors = bio_integrity_hw_sectors(bi,
 283                                        DIV_ROUND_UP(len, bi->tag_size));
 284
 285        if (nr_sectors * bi->tuple_size > bip->bip_size) {
 286                printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
 287                       __func__, nr_sectors * bi->tuple_size, bip->bip_size);
 288                return -1;
 289        }
 290
 291        if (set)
 292                bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
 293        else
 294                bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
 295
 296        return 0;
 297}
 298
 299/**
 300 * bio_integrity_set_tag - Attach a tag buffer to a bio
 301 * @bio:        bio to attach buffer to
 302 * @tag_buf:    Pointer to a buffer containing tag data
 303 * @len:        Length of the included buffer
 304 *
 305 * Description: Use this function to tag a bio by leveraging the extra
 306 * space provided by devices formatted with integrity protection.  The
 307 * size of the integrity buffer must be <= to the size reported by
 308 * bio_integrity_tag_size().
 309 */
 310int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
 311{
 312        BUG_ON(bio_data_dir(bio) != WRITE);
 313
 314        return bio_integrity_tag(bio, tag_buf, len, 1);
 315}
 316EXPORT_SYMBOL(bio_integrity_set_tag);
 317
 318/**
 319 * bio_integrity_get_tag - Retrieve a tag buffer from a bio
 320 * @bio:        bio to retrieve buffer from
 321 * @tag_buf:    Pointer to a buffer for the tag data
 322 * @len:        Length of the target buffer
 323 *
 324 * Description: Use this function to retrieve the tag buffer from a
 325 * completed I/O. The size of the integrity buffer must be <= to the
 326 * size reported by bio_integrity_tag_size().
 327 */
 328int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
 329{
 330        BUG_ON(bio_data_dir(bio) != READ);
 331
 332        return bio_integrity_tag(bio, tag_buf, len, 0);
 333}
 334EXPORT_SYMBOL(bio_integrity_get_tag);
 335
 336/**
 337 * bio_integrity_generate - Generate integrity metadata for a bio
 338 * @bio:        bio to generate integrity metadata for
 339 *
 340 * Description: Generates integrity metadata for a bio by calling the
 341 * block device's generation callback function.  The bio must have a
 342 * bip attached with enough room to accommodate the generated
 343 * integrity metadata.
 344 */
 345static void bio_integrity_generate(struct bio *bio)
 346{
 347        struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 348        struct blk_integrity_exchg bix;
 349        struct bio_vec *bv;
 350        sector_t sector = bio->bi_sector;
 351        unsigned int i, sectors, total;
 352        void *prot_buf = bio->bi_integrity->bip_buf;
 353
 354        total = 0;
 355        bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
 356        bix.sector_size = bi->sector_size;
 357
 358        bio_for_each_segment(bv, bio, i) {
 359                void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
 360                bix.data_buf = kaddr + bv->bv_offset;
 361                bix.data_size = bv->bv_len;
 362                bix.prot_buf = prot_buf;
 363                bix.sector = sector;
 364
 365                bi->generate_fn(&bix);
 366
 367                sectors = bv->bv_len / bi->sector_size;
 368                sector += sectors;
 369                prot_buf += sectors * bi->tuple_size;
 370                total += sectors * bi->tuple_size;
 371                BUG_ON(total > bio->bi_integrity->bip_size);
 372
 373                kunmap_atomic(kaddr, KM_USER0);
 374        }
 375}
 376
 377static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
 378{
 379        if (bi)
 380                return bi->tuple_size;
 381
 382        return 0;
 383}
 384
 385/**
 386 * bio_integrity_prep - Prepare bio for integrity I/O
 387 * @bio:        bio to prepare
 388 *
 389 * Description: Allocates a buffer for integrity metadata, maps the
 390 * pages and attaches them to a bio.  The bio must have data
 391 * direction, target device and start sector set priot to calling.  In
 392 * the WRITE case, integrity metadata will be generated using the
 393 * block device's integrity function.  In the READ case, the buffer
 394 * will be prepared for DMA and a suitable end_io handler set up.
 395 */
 396int bio_integrity_prep(struct bio *bio)
 397{
 398        struct bio_integrity_payload *bip;
 399        struct blk_integrity *bi;
 400        struct request_queue *q;
 401        void *buf;
 402        unsigned long start, end;
 403        unsigned int len, nr_pages;
 404        unsigned int bytes, offset, i;
 405        unsigned int sectors;
 406
 407        bi = bdev_get_integrity(bio->bi_bdev);
 408        q = bdev_get_queue(bio->bi_bdev);
 409        BUG_ON(bi == NULL);
 410        BUG_ON(bio_integrity(bio));
 411
 412        sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
 413
 414        /* Allocate kernel buffer for protection data */
 415        len = sectors * blk_integrity_tuple_size(bi);
 416        buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
 417        if (unlikely(buf == NULL)) {
 418                printk(KERN_ERR "could not allocate integrity buffer\n");
 419                return -ENOMEM;
 420        }
 421
 422        end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 423        start = ((unsigned long) buf) >> PAGE_SHIFT;
 424        nr_pages = end - start;
 425
 426        /* Allocate bio integrity payload and integrity vectors */
 427        bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
 428        if (unlikely(bip == NULL)) {
 429                printk(KERN_ERR "could not allocate data integrity bioset\n");
 430                kfree(buf);
 431                return -EIO;
 432        }
 433
 434        bip->bip_buf = buf;
 435        bip->bip_size = len;
 436        bip->bip_sector = bio->bi_sector;
 437
 438        /* Map it */
 439        offset = offset_in_page(buf);
 440        for (i = 0 ; i < nr_pages ; i++) {
 441                int ret;
 442                bytes = PAGE_SIZE - offset;
 443
 444                if (len <= 0)
 445                        break;
 446
 447                if (bytes > len)
 448                        bytes = len;
 449
 450                ret = bio_integrity_add_page(bio, virt_to_page(buf),
 451                                             bytes, offset);
 452
 453                if (ret == 0)
 454                        return 0;
 455
 456                if (ret < bytes)
 457                        break;
 458
 459                buf += bytes;
 460                len -= bytes;
 461                offset = 0;
 462        }
 463
 464        /* Install custom I/O completion handler if read verify is enabled */
 465        if (bio_data_dir(bio) == READ) {
 466                bip->bip_end_io = bio->bi_end_io;
 467                bio->bi_end_io = bio_integrity_endio;
 468        }
 469
 470        /* Auto-generate integrity metadata if this is a write */
 471        if (bio_data_dir(bio) == WRITE)
 472                bio_integrity_generate(bio);
 473
 474        return 0;
 475}
 476EXPORT_SYMBOL(bio_integrity_prep);
 477
 478/**
 479 * bio_integrity_verify - Verify integrity metadata for a bio
 480 * @bio:        bio to verify
 481 *
 482 * Description: This function is called to verify the integrity of a
 483 * bio.  The data in the bio io_vec is compared to the integrity
 484 * metadata returned by the HBA.
 485 */
 486static int bio_integrity_verify(struct bio *bio)
 487{
 488        struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 489        struct blk_integrity_exchg bix;
 490        struct bio_vec *bv;
 491        sector_t sector = bio->bi_integrity->bip_sector;
 492        unsigned int i, sectors, total, ret;
 493        void *prot_buf = bio->bi_integrity->bip_buf;
 494
 495        ret = total = 0;
 496        bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
 497        bix.sector_size = bi->sector_size;
 498
 499        bio_for_each_segment(bv, bio, i) {
 500                void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
 501                bix.data_buf = kaddr + bv->bv_offset;
 502                bix.data_size = bv->bv_len;
 503                bix.prot_buf = prot_buf;
 504                bix.sector = sector;
 505
 506                ret = bi->verify_fn(&bix);
 507
 508                if (ret) {
 509                        kunmap_atomic(kaddr, KM_USER0);
 510                        return ret;
 511                }
 512
 513                sectors = bv->bv_len / bi->sector_size;
 514                sector += sectors;
 515                prot_buf += sectors * bi->tuple_size;
 516                total += sectors * bi->tuple_size;
 517                BUG_ON(total > bio->bi_integrity->bip_size);
 518
 519                kunmap_atomic(kaddr, KM_USER0);
 520        }
 521
 522        return ret;
 523}
 524
 525/**
 526 * bio_integrity_verify_fn - Integrity I/O completion worker
 527 * @work:       Work struct stored in bio to be verified
 528 *
 529 * Description: This workqueue function is called to complete a READ
 530 * request.  The function verifies the transferred integrity metadata
 531 * and then calls the original bio end_io function.
 532 */
 533static void bio_integrity_verify_fn(struct work_struct *work)
 534{
 535        struct bio_integrity_payload *bip =
 536                container_of(work, struct bio_integrity_payload, bip_work);
 537        struct bio *bio = bip->bip_bio;
 538        int error;
 539
 540        error = bio_integrity_verify(bio);
 541
 542        /* Restore original bio completion handler */
 543        bio->bi_end_io = bip->bip_end_io;
 544        bio_endio(bio, error);
 545}
 546
 547/**
 548 * bio_integrity_endio - Integrity I/O completion function
 549 * @bio:        Protected bio
 550 * @error:      Pointer to errno
 551 *
 552 * Description: Completion for integrity I/O
 553 *
 554 * Normally I/O completion is done in interrupt context.  However,
 555 * verifying I/O integrity is a time-consuming task which must be run
 556 * in process context.  This function postpones completion
 557 * accordingly.
 558 */
 559void bio_integrity_endio(struct bio *bio, int error)
 560{
 561        struct bio_integrity_payload *bip = bio->bi_integrity;
 562
 563        BUG_ON(bip->bip_bio != bio);
 564
 565        /* In case of an I/O error there is no point in verifying the
 566         * integrity metadata.  Restore original bio end_io handler
 567         * and run it.
 568         */
 569        if (error) {
 570                bio->bi_end_io = bip->bip_end_io;
 571                bio_endio(bio, error);
 572
 573                return;
 574        }
 575
 576        INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
 577        queue_work(kintegrityd_wq, &bip->bip_work);
 578}
 579EXPORT_SYMBOL(bio_integrity_endio);
 580
 581/**
 582 * bio_integrity_mark_head - Advance bip_vec skip bytes
 583 * @bip:        Integrity vector to advance
 584 * @skip:       Number of bytes to advance it
 585 */
 586void bio_integrity_mark_head(struct bio_integrity_payload *bip,
 587                             unsigned int skip)
 588{
 589        struct bio_vec *iv;
 590        unsigned int i;
 591
 592        bip_for_each_vec(iv, bip, i) {
 593                if (skip == 0) {
 594                        bip->bip_idx = i;
 595                        return;
 596                } else if (skip >= iv->bv_len) {
 597                        skip -= iv->bv_len;
 598                } else { /* skip < iv->bv_len) */
 599                        iv->bv_offset += skip;
 600                        iv->bv_len -= skip;
 601                        bip->bip_idx = i;
 602                        return;
 603                }
 604        }
 605}
 606
 607/**
 608 * bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
 609 * @bip:        Integrity vector to truncate
 610 * @len:        New length of integrity vector
 611 */
 612void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
 613                             unsigned int len)
 614{
 615        struct bio_vec *iv;
 616        unsigned int i;
 617
 618        bip_for_each_vec(iv, bip, i) {
 619                if (len == 0) {
 620                        bip->bip_vcnt = i;
 621                        return;
 622                } else if (len >= iv->bv_len) {
 623                        len -= iv->bv_len;
 624                } else { /* len < iv->bv_len) */
 625                        iv->bv_len = len;
 626                        len = 0;
 627                }
 628        }
 629}
 630
 631/**
 632 * bio_integrity_advance - Advance integrity vector
 633 * @bio:        bio whose integrity vector to update
 634 * @bytes_done: number of data bytes that have been completed
 635 *
 636 * Description: This function calculates how many integrity bytes the
 637 * number of completed data bytes correspond to and advances the
 638 * integrity vector accordingly.
 639 */
 640void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
 641{
 642        struct bio_integrity_payload *bip = bio->bi_integrity;
 643        struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 644        unsigned int nr_sectors;
 645
 646        BUG_ON(bip == NULL);
 647        BUG_ON(bi == NULL);
 648
 649        nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
 650        bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
 651}
 652EXPORT_SYMBOL(bio_integrity_advance);
 653
 654/**
 655 * bio_integrity_trim - Trim integrity vector
 656 * @bio:        bio whose integrity vector to update
 657 * @offset:     offset to first data sector
 658 * @sectors:    number of data sectors
 659 *
 660 * Description: Used to trim the integrity vector in a cloned bio.
 661 * The ivec will be advanced corresponding to 'offset' data sectors
 662 * and the length will be truncated corresponding to 'len' data
 663 * sectors.
 664 */
 665void bio_integrity_trim(struct bio *bio, unsigned int offset,
 666                        unsigned int sectors)
 667{
 668        struct bio_integrity_payload *bip = bio->bi_integrity;
 669        struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 670        unsigned int nr_sectors;
 671
 672        BUG_ON(bip == NULL);
 673        BUG_ON(bi == NULL);
 674        BUG_ON(!bio_flagged(bio, BIO_CLONED));
 675
 676        nr_sectors = bio_integrity_hw_sectors(bi, sectors);
 677        bip->bip_sector = bip->bip_sector + offset;
 678        bio_integrity_mark_head(bip, offset * bi->tuple_size);
 679        bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
 680}
 681EXPORT_SYMBOL(bio_integrity_trim);
 682
 683/**
 684 * bio_integrity_split - Split integrity metadata
 685 * @bio:        Protected bio
 686 * @bp:         Resulting bio_pair
 687 * @sectors:    Offset
 688 *
 689 * Description: Splits an integrity page into a bio_pair.
 690 */
 691void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
 692{
 693        struct blk_integrity *bi;
 694        struct bio_integrity_payload *bip = bio->bi_integrity;
 695        unsigned int nr_sectors;
 696
 697        if (bio_integrity(bio) == 0)
 698                return;
 699
 700        bi = bdev_get_integrity(bio->bi_bdev);
 701        BUG_ON(bi == NULL);
 702        BUG_ON(bip->bip_vcnt != 1);
 703
 704        nr_sectors = bio_integrity_hw_sectors(bi, sectors);
 705
 706        bp->bio1.bi_integrity = &bp->bip1;
 707        bp->bio2.bi_integrity = &bp->bip2;
 708
 709        bp->iv1 = bip->bip_vec[0];
 710        bp->iv2 = bip->bip_vec[0];
 711
 712        bp->bip1.bip_vec[0] = bp->iv1;
 713        bp->bip2.bip_vec[0] = bp->iv2;
 714
 715        bp->iv1.bv_len = sectors * bi->tuple_size;
 716        bp->iv2.bv_offset += sectors * bi->tuple_size;
 717        bp->iv2.bv_len -= sectors * bi->tuple_size;
 718
 719        bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
 720        bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
 721
 722        bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
 723        bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
 724}
 725EXPORT_SYMBOL(bio_integrity_split);
 726
 727/**
 728 * bio_integrity_clone - Callback for cloning bios with integrity metadata
 729 * @bio:        New bio
 730 * @bio_src:    Original bio
 731 * @gfp_mask:   Memory allocation mask
 732 * @bs:         bio_set to allocate bip from
 733 *
 734 * Description: Called to allocate a bip when cloning a bio
 735 */
 736int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 737                        gfp_t gfp_mask, struct bio_set *bs)
 738{
 739        struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
 740        struct bio_integrity_payload *bip;
 741
 742        BUG_ON(bip_src == NULL);
 743
 744        bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
 745
 746        if (bip == NULL)
 747                return -EIO;
 748
 749        memcpy(bip->bip_vec, bip_src->bip_vec,
 750               bip_src->bip_vcnt * sizeof(struct bio_vec));
 751
 752        bip->bip_sector = bip_src->bip_sector;
 753        bip->bip_vcnt = bip_src->bip_vcnt;
 754        bip->bip_idx = bip_src->bip_idx;
 755
 756        return 0;
 757}
 758EXPORT_SYMBOL(bio_integrity_clone);
 759
 760int bioset_integrity_create(struct bio_set *bs, int pool_size)
 761{
 762        unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
 763
 764        if (bs->bio_integrity_pool)
 765                return 0;
 766
 767        bs->bio_integrity_pool =
 768                mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
 769
 770        if (!bs->bio_integrity_pool)
 771                return -1;
 772
 773        return 0;
 774}
 775EXPORT_SYMBOL(bioset_integrity_create);
 776
 777void bioset_integrity_free(struct bio_set *bs)
 778{
 779        if (bs->bio_integrity_pool)
 780                mempool_destroy(bs->bio_integrity_pool);
 781}
 782EXPORT_SYMBOL(bioset_integrity_free);
 783
 784void __init bio_integrity_init(void)
 785{
 786        unsigned int i;
 787
 788        /*
 789         * kintegrityd won't block much but may burn a lot of CPU cycles.
 790         * Make it highpri CPU intensive wq with max concurrency of 1.
 791         */
 792        kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
 793                                         WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
 794        if (!kintegrityd_wq)
 795                panic("Failed to create kintegrityd\n");
 796
 797        for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
 798                unsigned int size;
 799
 800                size = sizeof(struct bio_integrity_payload)
 801                        + bip_slab[i].nr_vecs * sizeof(struct bio_vec);
 802
 803                bip_slab[i].slab =
 804                        kmem_cache_create(bip_slab[i].name, size, 0,
 805                                          SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 806        }
 807}
 808
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.