fs/bio-integrity.c

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