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