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