fs/bio-integrity.c

   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
  29 struct 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) }
  36 struct 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
  41 static struct workqueue_struct *kintegrityd_wq;
  42
  43 static 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
  63 static 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  */
  82 struct 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 }
 116 EXPORT_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  */
 128 struct 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 }
 134 EXPORT_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  */
 144 void 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 }
 162 EXPORT_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  */
 173 int 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 }
 194 EXPORT_SYMBOL(bio_integrity_add_page);
 195
 196 static 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  */
 223 int 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 }
 231 EXPORT_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  */
 243 static 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  */
 261 unsigned 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 }
 269 EXPORT_SYMBOL(bio_integrity_tag_size);
 270
 271 int 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  */
 310 int 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 }
 316 EXPORT_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  */
 328 int 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 }
 334 EXPORT_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  */
 345 static 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
 377 static 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  */
 396 int 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 | __GFP_NOFAIL | q->bounce_gfp);
 417         if (unlikely(buf == NULL)) {
 418                 printk(KERN_ERR "could not allocate integrity buffer\n");
 419                 return -EIO;
 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 }
 476 EXPORT_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  */
 486 static 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  */
 533 static 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  */
 559 void 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 }
 579 EXPORT_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  */
 586 void 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  */
 612 void 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  */
 640 void 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 }
 652 EXPORT_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  */
 665 void 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 }
 681 EXPORT_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  */
 691 void 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 }
 725 EXPORT_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  */
 736 int 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 }
 758 EXPORT_SYMBOL(bio_integrity_clone);
 759
 760 int bioset_integrity_create(struct bio_set *bs, int pool_size)
 761 {
 762         unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
 763
 764         bs->bio_integrity_pool =
 765                 mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
 766
 767         if (!bs->bio_integrity_pool)
 768                 return -1;
 769
 770         return 0;
 771 }
 772 EXPORT_SYMBOL(bioset_integrity_create);
 773
 774 void bioset_integrity_free(struct bio_set *bs)
 775 {
 776         if (bs->bio_integrity_pool)
 777                 mempool_destroy(bs->bio_integrity_pool);
 778 }
 779 EXPORT_SYMBOL(bioset_integrity_free);
 780
 781 void __init bio_integrity_init(void)
 782 {
 783         unsigned int i;
 784
 785         kintegrityd_wq = create_workqueue("kintegrityd");
 786         if (!kintegrityd_wq)
 787                 panic("Failed to create kintegrityd\n");
 788
 789         for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
 790                 unsigned int size;
 791
 792                 size = sizeof(struct bio_integrity_payload)
 793                         + bip_slab[i].nr_vecs * sizeof(struct bio_vec);
 794
 795                 bip_slab[i].slab =
 796                         kmem_cache_create(bip_slab[i].name, size, 0,
 797                                           SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 798         }
 799 }