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) && !bio_flagged(bio, BIO_FS_INTEGRITY)
 111             && bip->bip_buf != NULL)
 112                 kfree(bip->bip_buf);
 113
 114         bvec_free_bs(bs, bip->bip_vec, bip->bip_pool);
 115         mempool_free(bip, bs->bio_integrity_pool);
 116
 117         bio->bi_integrity = NULL;
 118 }
 119 EXPORT_SYMBOL(bio_integrity_free);
 120
 121 /**
 122  * bio_integrity_add_page - Attach integrity metadata
 123  * @bio:        bio to update
 124  * @page:       page containing integrity metadata
 125  * @len:        number of bytes of integrity metadata in page
 126  * @offset:     start offset within page
 127  *
 128  * Description: Attach a page containing integrity metadata to bio.
 129  */
 130 int bio_integrity_add_page(struct bio *bio, struct page *page,
 131                            unsigned int len, unsigned int offset)
 132 {
 133         struct bio_integrity_payload *bip = bio->bi_integrity;
 134         struct bio_vec *iv;
 135
 136         if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_pool)) {
 137                 printk(KERN_ERR "%s: bip_vec full\n", __func__);
 138                 return 0;
 139         }
 140
 141         iv = bip_vec_idx(bip, bip->bip_vcnt);
 142         BUG_ON(iv == 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 int bdev_integrity_enabled(struct block_device *bdev, int rw)
 154 {
 155         struct blk_integrity *bi = bdev_get_integrity(bdev);
 156
 157         if (bi == NULL)
 158                 return 0;
 159
 160         if (rw == READ && bi->verify_fn != NULL &&
 161             (bi->flags & INTEGRITY_FLAG_READ))
 162                 return 1;
 163
 164         if (rw == WRITE && bi->generate_fn != NULL &&
 165             (bi->flags & INTEGRITY_FLAG_WRITE))
 166                 return 1;
 167
 168         return 0;
 169 }
 170
 171 /**
 172  * bio_integrity_enabled - Check whether integrity can be passed
 173  * @bio:        bio to check
 174  *
 175  * Description: Determines whether bio_integrity_prep() can be called
 176  * on this bio or not.  bio data direction and target device must be
 177  * set prior to calling.  The functions honors the write_generate and
 178  * read_verify flags in sysfs.
 179  */
 180 int bio_integrity_enabled(struct bio *bio)
 181 {
 182         /* Already protected? */
 183         if (bio_integrity(bio))
 184                 return 0;
 185
 186         return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
 187 }
 188 EXPORT_SYMBOL(bio_integrity_enabled);
 189
 190 /**
 191  * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
 192  * @bi:         blk_integrity profile for device
 193  * @sectors:    Number of 512 sectors to convert
 194  *
 195  * Description: The block layer calculates everything in 512 byte
 196  * sectors but integrity metadata is done in terms of the hardware
 197  * sector size of the storage device.  Convert the block layer sectors
 198  * to physical sectors.
 199  */
 200 static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
 201                                                     unsigned int sectors)
 202 {
 203         /* At this point there are only 512b or 4096b DIF/EPP devices */
 204         if (bi->sector_size == 4096)
 205                 return sectors >>= 3;
 206
 207         return sectors;
 208 }
 209
 210 /**
 211  * bio_integrity_tag_size - Retrieve integrity tag space
 212  * @bio:        bio to inspect
 213  *
 214  * Description: Returns the maximum number of tag bytes that can be
 215  * attached to this bio. Filesystems can use this to determine how
 216  * much metadata to attach to an I/O.
 217  */
 218 unsigned int bio_integrity_tag_size(struct bio *bio)
 219 {
 220         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 221
 222         BUG_ON(bio->bi_size == 0);
 223
 224         return bi->tag_size * (bio->bi_size / bi->sector_size);
 225 }
 226 EXPORT_SYMBOL(bio_integrity_tag_size);
 227
 228 int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
 229 {
 230         struct bio_integrity_payload *bip = bio->bi_integrity;
 231         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 232         unsigned int nr_sectors;
 233
 234         BUG_ON(bip->bip_buf == NULL);
 235
 236         if (bi->tag_size == 0)
 237                 return -1;
 238
 239         nr_sectors = bio_integrity_hw_sectors(bi,
 240                                         DIV_ROUND_UP(len, bi->tag_size));
 241
 242         if (nr_sectors * bi->tuple_size > bip->bip_size) {
 243                 printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
 244                        __func__, nr_sectors * bi->tuple_size, bip->bip_size);
 245                 return -1;
 246         }
 247
 248         if (set)
 249                 bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
 250         else
 251                 bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
 252
 253         return 0;
 254 }
 255
 256 /**
 257  * bio_integrity_set_tag - Attach a tag buffer to a bio
 258  * @bio:        bio to attach buffer to
 259  * @tag_buf:    Pointer to a buffer containing tag data
 260  * @len:        Length of the included buffer
 261  *
 262  * Description: Use this function to tag a bio by leveraging the extra
 263  * space provided by devices formatted with integrity protection.  The
 264  * size of the integrity buffer must be <= to the size reported by
 265  * bio_integrity_tag_size().
 266  */
 267 int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
 268 {
 269         BUG_ON(bio_data_dir(bio) != WRITE);
 270
 271         return bio_integrity_tag(bio, tag_buf, len, 1);
 272 }
 273 EXPORT_SYMBOL(bio_integrity_set_tag);
 274
 275 /**
 276  * bio_integrity_get_tag - Retrieve a tag buffer from a bio
 277  * @bio:        bio to retrieve buffer from
 278  * @tag_buf:    Pointer to a buffer for the tag data
 279  * @len:        Length of the target buffer
 280  *
 281  * Description: Use this function to retrieve the tag buffer from a
 282  * completed I/O. The size of the integrity buffer must be <= to the
 283  * size reported by bio_integrity_tag_size().
 284  */
 285 int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
 286 {
 287         BUG_ON(bio_data_dir(bio) != READ);
 288
 289         return bio_integrity_tag(bio, tag_buf, len, 0);
 290 }
 291 EXPORT_SYMBOL(bio_integrity_get_tag);
 292
 293 /**
 294  * bio_integrity_generate - Generate integrity metadata for a bio
 295  * @bio:        bio to generate integrity metadata for
 296  *
 297  * Description: Generates integrity metadata for a bio by calling the
 298  * block device's generation callback function.  The bio must have a
 299  * bip attached with enough room to accommodate the generated
 300  * integrity metadata.
 301  */
 302 static void bio_integrity_generate(struct bio *bio)
 303 {
 304         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 305         struct blk_integrity_exchg bix;
 306         struct bio_vec *bv;
 307         sector_t sector = bio->bi_sector;
 308         unsigned int i, sectors, total;
 309         void *prot_buf = bio->bi_integrity->bip_buf;
 310
 311         total = 0;
 312         bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
 313         bix.sector_size = bi->sector_size;
 314
 315         bio_for_each_segment(bv, bio, i) {
 316                 void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
 317                 bix.data_buf = kaddr + bv->bv_offset;
 318                 bix.data_size = bv->bv_len;
 319                 bix.prot_buf = prot_buf;
 320                 bix.sector = sector;
 321
 322                 bi->generate_fn(&bix);
 323
 324                 sectors = bv->bv_len / bi->sector_size;
 325                 sector += sectors;
 326                 prot_buf += sectors * bi->tuple_size;
 327                 total += sectors * bi->tuple_size;
 328                 BUG_ON(total > bio->bi_integrity->bip_size);
 329
 330                 kunmap_atomic(kaddr, KM_USER0);
 331         }
 332 }
 333
 334 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
 335 {
 336         if (bi)
 337                 return bi->tuple_size;
 338
 339         return 0;
 340 }
 341
 342 /**
 343  * bio_integrity_prep - Prepare bio for integrity I/O
 344  * @bio:        bio to prepare
 345  *
 346  * Description: Allocates a buffer for integrity metadata, maps the
 347  * pages and attaches them to a bio.  The bio must have data
 348  * direction, target device and start sector set priot to calling.  In
 349  * the WRITE case, integrity metadata will be generated using the
 350  * block device's integrity function.  In the READ case, the buffer
 351  * will be prepared for DMA and a suitable end_io handler set up.
 352  */
 353 int bio_integrity_prep(struct bio *bio)
 354 {
 355         struct bio_integrity_payload *bip;
 356         struct blk_integrity *bi;
 357         struct request_queue *q;
 358         void *buf;
 359         unsigned long start, end;
 360         unsigned int len, nr_pages;
 361         unsigned int bytes, offset, i;
 362         unsigned int sectors;
 363
 364         bi = bdev_get_integrity(bio->bi_bdev);
 365         q = bdev_get_queue(bio->bi_bdev);
 366         BUG_ON(bi == NULL);
 367         BUG_ON(bio_integrity(bio));
 368
 369         sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
 370
 371         /* Allocate kernel buffer for protection data */
 372         len = sectors * blk_integrity_tuple_size(bi);
 373         buf = kmalloc(len, GFP_NOIO | __GFP_NOFAIL | q->bounce_gfp);
 374         if (unlikely(buf == NULL)) {
 375                 printk(KERN_ERR "could not allocate integrity buffer\n");
 376                 return -EIO;
 377         }
 378
 379         end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 380         start = ((unsigned long) buf) >> PAGE_SHIFT;
 381         nr_pages = end - start;
 382
 383         /* Allocate bio integrity payload and integrity vectors */
 384         bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
 385         if (unlikely(bip == NULL)) {
 386                 printk(KERN_ERR "could not allocate data integrity bioset\n");
 387                 kfree(buf);
 388                 return -EIO;
 389         }
 390
 391         bip->bip_buf = buf;
 392         bip->bip_size = len;
 393         bip->bip_sector = bio->bi_sector;
 394
 395         /* Map it */
 396         offset = offset_in_page(buf);
 397         for (i = 0 ; i < nr_pages ; i++) {
 398                 int ret;
 399                 bytes = PAGE_SIZE - offset;
 400
 401                 if (len <= 0)
 402                         break;
 403
 404                 if (bytes > len)
 405                         bytes = len;
 406
 407                 ret = bio_integrity_add_page(bio, virt_to_page(buf),
 408                                              bytes, offset);
 409
 410                 if (ret == 0)
 411                         return 0;
 412
 413                 if (ret < bytes)
 414                         break;
 415
 416                 buf += bytes;
 417                 len -= bytes;
 418                 offset = 0;
 419         }
 420
 421         /* Install custom I/O completion handler if read verify is enabled */
 422         if (bio_data_dir(bio) == READ) {
 423                 bip->bip_end_io = bio->bi_end_io;
 424                 bio->bi_end_io = bio_integrity_endio;
 425         }
 426
 427         /* Auto-generate integrity metadata if this is a write */
 428         if (bio_data_dir(bio) == WRITE)
 429                 bio_integrity_generate(bio);
 430
 431         return 0;
 432 }
 433 EXPORT_SYMBOL(bio_integrity_prep);
 434
 435 /**
 436  * bio_integrity_verify - Verify integrity metadata for a bio
 437  * @bio:        bio to verify
 438  *
 439  * Description: This function is called to verify the integrity of a
 440  * bio.  The data in the bio io_vec is compared to the integrity
 441  * metadata returned by the HBA.
 442  */
 443 static int bio_integrity_verify(struct bio *bio)
 444 {
 445         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 446         struct blk_integrity_exchg bix;
 447         struct bio_vec *bv;
 448         sector_t sector = bio->bi_integrity->bip_sector;
 449         unsigned int i, sectors, total, ret;
 450         void *prot_buf = bio->bi_integrity->bip_buf;
 451
 452         ret = total = 0;
 453         bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
 454         bix.sector_size = bi->sector_size;
 455
 456         bio_for_each_segment(bv, bio, i) {
 457                 void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
 458                 bix.data_buf = kaddr + bv->bv_offset;
 459                 bix.data_size = bv->bv_len;
 460                 bix.prot_buf = prot_buf;
 461                 bix.sector = sector;
 462
 463                 ret = bi->verify_fn(&bix);
 464
 465                 if (ret) {
 466                         kunmap_atomic(kaddr, KM_USER0);
 467                         return ret;
 468                 }
 469
 470                 sectors = bv->bv_len / bi->sector_size;
 471                 sector += sectors;
 472                 prot_buf += sectors * bi->tuple_size;
 473                 total += sectors * bi->tuple_size;
 474                 BUG_ON(total > bio->bi_integrity->bip_size);
 475
 476                 kunmap_atomic(kaddr, KM_USER0);
 477         }
 478
 479         return ret;
 480 }
 481
 482 /**
 483  * bio_integrity_verify_fn - Integrity I/O completion worker
 484  * @work:       Work struct stored in bio to be verified
 485  *
 486  * Description: This workqueue function is called to complete a READ
 487  * request.  The function verifies the transferred integrity metadata
 488  * and then calls the original bio end_io function.
 489  */
 490 static void bio_integrity_verify_fn(struct work_struct *work)
 491 {
 492         struct bio_integrity_payload *bip =
 493                 container_of(work, struct bio_integrity_payload, bip_work);
 494         struct bio *bio = bip->bip_bio;
 495         int error;
 496
 497         error = bio_integrity_verify(bio);
 498
 499         /* Restore original bio completion handler */
 500         bio->bi_end_io = bip->bip_end_io;
 501         bio_endio(bio, error);
 502 }
 503
 504 /**
 505  * bio_integrity_endio - Integrity I/O completion function
 506  * @bio:        Protected bio
 507  * @error:      Pointer to errno
 508  *
 509  * Description: Completion for integrity I/O
 510  *
 511  * Normally I/O completion is done in interrupt context.  However,
 512  * verifying I/O integrity is a time-consuming task which must be run
 513  * in process context.  This function postpones completion
 514  * accordingly.
 515  */
 516 void bio_integrity_endio(struct bio *bio, int error)
 517 {
 518         struct bio_integrity_payload *bip = bio->bi_integrity;
 519
 520         BUG_ON(bip->bip_bio != bio);
 521
 522         /* In case of an I/O error there is no point in verifying the
 523          * integrity metadata.  Restore original bio end_io handler
 524          * and run it.
 525          */
 526         if (error) {
 527                 bio->bi_end_io = bip->bip_end_io;
 528                 bio_endio(bio, error);
 529
 530                 return;
 531         }
 532
 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  * @gfp_mask:   Memory allocation mask
 689  * @bs:         bio_set to allocate bip from
 690  *
 691  * Description: Called to allocate a bip when cloning a bio
 692  */
 693 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 694                         gfp_t gfp_mask, struct bio_set *bs)
 695 {
 696         struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
 697         struct bio_integrity_payload *bip;
 698
 699         BUG_ON(bip_src == NULL);
 700
 701         bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
 702
 703         if (bip == NULL)
 704                 return -EIO;
 705
 706         memcpy(bip->bip_vec, bip_src->bip_vec,
 707                bip_src->bip_vcnt * sizeof(struct bio_vec));
 708
 709         bip->bip_sector = bip_src->bip_sector;
 710         bip->bip_vcnt = bip_src->bip_vcnt;
 711         bip->bip_idx = bip_src->bip_idx;
 712
 713         return 0;
 714 }
 715 EXPORT_SYMBOL(bio_integrity_clone);
 716
 717 int bioset_integrity_create(struct bio_set *bs, int pool_size)
 718 {
 719         bs->bio_integrity_pool = mempool_create_slab_pool(pool_size,
 720                                                           bio_integrity_slab);
 721         if (!bs->bio_integrity_pool)
 722                 return -1;
 723
 724         return 0;
 725 }
 726 EXPORT_SYMBOL(bioset_integrity_create);
 727
 728 void bioset_integrity_free(struct bio_set *bs)
 729 {
 730         if (bs->bio_integrity_pool)
 731                 mempool_destroy(bs->bio_integrity_pool);
 732 }
 733 EXPORT_SYMBOL(bioset_integrity_free);
 734
 735 void __init bio_integrity_init_slab(void)
 736 {
 737         bio_integrity_slab = KMEM_CACHE(bio_integrity_payload,
 738                                         SLAB_HWCACHE_ALIGN|SLAB_PANIC);
 739 }
 740
 741 static int __init integrity_init(void)
 742 {
 743         kintegrityd_wq = create_workqueue("kintegrityd");
 744
 745         if (!kintegrityd_wq)
 746                 panic("Failed to create kintegrityd\n");
 747
 748         return 0;
 749 }
 750 subsys_initcall(integrity_init);