block/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 #define BIP_INLINE_VECS 4
  31
  32 static struct kmem_cache *bip_slab;
  33 static struct workqueue_struct *kintegrityd_wq;
  34
  35 /**
  36  * bio_integrity_alloc - Allocate integrity payload and attach it to bio
  37  * @bio:        bio to attach integrity metadata to
  38  * @gfp_mask:   Memory allocation mask
  39  * @nr_vecs:    Number of integrity metadata scatter-gather elements
  40  *
  41  * Description: This function prepares a bio for attaching integrity
  42  * metadata.  nr_vecs specifies the maximum number of pages containing
  43  * integrity metadata that can be attached.
  44  */
  45 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
  46                                                   gfp_t gfp_mask,
  47                                                   unsigned int nr_vecs)
  48 {
  49         struct bio_integrity_payload *bip;
  50         struct bio_set *bs = bio->bi_pool;
  51         unsigned long idx = BIO_POOL_NONE;
  52         unsigned inline_vecs;
  53
  54         if (!bs) {
  55                 bip = kmalloc(sizeof(struct bio_integrity_payload) +
  56                               sizeof(struct bio_vec) * nr_vecs, gfp_mask);
  57                 inline_vecs = nr_vecs;
  58         } else {
  59                 bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
  60                 inline_vecs = BIP_INLINE_VECS;
  61         }
  62
  63         if (unlikely(!bip))
  64                 return NULL;
  65
  66         memset(bip, 0, sizeof(*bip));
  67
  68         if (nr_vecs > inline_vecs) {
  69                 bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
  70                                           bs->bvec_integrity_pool);
  71                 if (!bip->bip_vec)
  72                         goto err;
  73                 bip->bip_max_vcnt = bvec_nr_vecs(idx);
  74         } else {
  75                 bip->bip_vec = bip->bip_inline_vecs;
  76                 bip->bip_max_vcnt = inline_vecs;
  77         }
  78
  79         bip->bip_slab = idx;
  80         bip->bip_bio = bio;
  81         bio->bi_integrity = bip;
  82
  83         return bip;
  84 err:
  85         mempool_free(bip, bs->bio_integrity_pool);
  86         return NULL;
  87 }
  88 EXPORT_SYMBOL(bio_integrity_alloc);
  89
  90 /**
  91  * bio_integrity_free - Free bio integrity payload
  92  * @bio:        bio containing bip to be freed
  93  *
  94  * Description: Used to free the integrity portion of a bio. Usually
  95  * called from bio_free().
  96  */
  97 void bio_integrity_free(struct bio *bio)
  98 {
  99         struct bio_integrity_payload *bip = bio->bi_integrity;
 100         struct bio_set *bs = bio->bi_pool;
 101
 102         if (bip->bip_owns_buf)
 103                 kfree(bip->bip_buf);
 104
 105         if (bs) {
 106                 if (bip->bip_slab != BIO_POOL_NONE)
 107                         bvec_free(bs->bvec_integrity_pool, bip->bip_vec,
 108                                   bip->bip_slab);
 109
 110                 mempool_free(bip, bs->bio_integrity_pool);
 111         } else {
 112                 kfree(bip);
 113         }
 114
 115         bio->bi_integrity = NULL;
 116 }
 117 EXPORT_SYMBOL(bio_integrity_free);
 118
 119 /**
 120  * bio_integrity_add_page - Attach integrity metadata
 121  * @bio:        bio to update
 122  * @page:       page containing integrity metadata
 123  * @len:        number of bytes of integrity metadata in page
 124  * @offset:     start offset within page
 125  *
 126  * Description: Attach a page containing integrity metadata to bio.
 127  */
 128 int bio_integrity_add_page(struct bio *bio, struct page *page,
 129                            unsigned int len, unsigned int offset)
 130 {
 131         struct bio_integrity_payload *bip = bio->bi_integrity;
 132         struct bio_vec *iv;
 133
 134         if (bip->bip_vcnt >= bip->bip_max_vcnt) {
 135                 printk(KERN_ERR "%s: bip_vec full\n", __func__);
 136                 return 0;
 137         }
 138
 139         iv = bip->bip_vec + bip->bip_vcnt;
 140
 141         iv->bv_page = page;
 142         iv->bv_len = len;
 143         iv->bv_offset = offset;
 144         bip->bip_vcnt++;
 145
 146         return len;
 147 }
 148 EXPORT_SYMBOL(bio_integrity_add_page);
 149
 150 static int bdev_integrity_enabled(struct block_device *bdev, int rw)
 151 {
 152         struct blk_integrity *bi = bdev_get_integrity(bdev);
 153
 154         if (bi == NULL)
 155                 return 0;
 156
 157         if (rw == READ && bi->verify_fn != NULL &&
 158             (bi->flags & INTEGRITY_FLAG_READ))
 159                 return 1;
 160
 161         if (rw == WRITE && bi->generate_fn != NULL &&
 162             (bi->flags & INTEGRITY_FLAG_WRITE))
 163                 return 1;
 164
 165         return 0;
 166 }
 167
 168 /**
 169  * bio_integrity_enabled - Check whether integrity can be passed
 170  * @bio:        bio to check
 171  *
 172  * Description: Determines whether bio_integrity_prep() can be called
 173  * on this bio or not.  bio data direction and target device must be
 174  * set prior to calling.  The functions honors the write_generate and
 175  * read_verify flags in sysfs.
 176  */
 177 int bio_integrity_enabled(struct bio *bio)
 178 {
 179         if (!bio_is_rw(bio))
 180                 return 0;
 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 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
 211                                                unsigned int sectors)
 212 {
 213         return bio_integrity_hw_sectors(bi, sectors) * bi->tuple_size;
 214 }
 215
 216 /**
 217  * bio_integrity_tag_size - Retrieve integrity tag space
 218  * @bio:        bio to inspect
 219  *
 220  * Description: Returns the maximum number of tag bytes that can be
 221  * attached to this bio. Filesystems can use this to determine how
 222  * much metadata to attach to an I/O.
 223  */
 224 unsigned int bio_integrity_tag_size(struct bio *bio)
 225 {
 226         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 227
 228         BUG_ON(bio->bi_iter.bi_size == 0);
 229
 230         return bi->tag_size * (bio->bi_iter.bi_size / bi->sector_size);
 231 }
 232 EXPORT_SYMBOL(bio_integrity_tag_size);
 233
 234 static int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len,
 235                              int set)
 236 {
 237         struct bio_integrity_payload *bip = bio->bi_integrity;
 238         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 239         unsigned int nr_sectors;
 240
 241         BUG_ON(bip->bip_buf == NULL);
 242
 243         if (bi->tag_size == 0)
 244                 return -1;
 245
 246         nr_sectors = bio_integrity_hw_sectors(bi,
 247                                         DIV_ROUND_UP(len, bi->tag_size));
 248
 249         if (nr_sectors * bi->tuple_size > bip->bip_iter.bi_size) {
 250                 printk(KERN_ERR "%s: tag too big for bio: %u > %u\n", __func__,
 251                        nr_sectors * bi->tuple_size, bip->bip_iter.bi_size);
 252                 return -1;
 253         }
 254
 255         if (set)
 256                 bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
 257         else
 258                 bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
 259
 260         return 0;
 261 }
 262
 263 /**
 264  * bio_integrity_set_tag - Attach a tag buffer to a bio
 265  * @bio:        bio to attach buffer to
 266  * @tag_buf:    Pointer to a buffer containing tag data
 267  * @len:        Length of the included buffer
 268  *
 269  * Description: Use this function to tag a bio by leveraging the extra
 270  * space provided by devices formatted with integrity protection.  The
 271  * size of the integrity buffer must be <= to the size reported by
 272  * bio_integrity_tag_size().
 273  */
 274 int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
 275 {
 276         BUG_ON(bio_data_dir(bio) != WRITE);
 277
 278         return bio_integrity_tag(bio, tag_buf, len, 1);
 279 }
 280 EXPORT_SYMBOL(bio_integrity_set_tag);
 281
 282 /**
 283  * bio_integrity_get_tag - Retrieve a tag buffer from a bio
 284  * @bio:        bio to retrieve buffer from
 285  * @tag_buf:    Pointer to a buffer for the tag data
 286  * @len:        Length of the target buffer
 287  *
 288  * Description: Use this function to retrieve the tag buffer from a
 289  * completed I/O. The size of the integrity buffer must be <= to the
 290  * size reported by bio_integrity_tag_size().
 291  */
 292 int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
 293 {
 294         BUG_ON(bio_data_dir(bio) != READ);
 295
 296         return bio_integrity_tag(bio, tag_buf, len, 0);
 297 }
 298 EXPORT_SYMBOL(bio_integrity_get_tag);
 299
 300 /**
 301  * bio_integrity_generate_verify - Generate/verify integrity metadata for a bio
 302  * @bio:        bio to generate/verify integrity metadata for
 303  * @operate:    operate number, 1 for generate, 0 for verify
 304  */
 305 static int bio_integrity_generate_verify(struct bio *bio, int operate)
 306 {
 307         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 308         struct blk_integrity_exchg bix;
 309         struct bio_vec *bv;
 310         sector_t sector;
 311         unsigned int sectors, ret = 0, i;
 312         void *prot_buf = bio->bi_integrity->bip_buf;
 313
 314         if (operate)
 315                 sector = bio->bi_iter.bi_sector;
 316         else
 317                 sector = bio->bi_integrity->bip_iter.bi_sector;
 318
 319         bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
 320         bix.sector_size = bi->sector_size;
 321
 322         bio_for_each_segment_all(bv, bio, i) {
 323                 void *kaddr = kmap_atomic(bv->bv_page);
 324                 bix.data_buf = kaddr + bv->bv_offset;
 325                 bix.data_size = bv->bv_len;
 326                 bix.prot_buf = prot_buf;
 327                 bix.sector = sector;
 328
 329                 if (operate)
 330                         bi->generate_fn(&bix);
 331                 else {
 332                         ret = bi->verify_fn(&bix);
 333                         if (ret) {
 334                                 kunmap_atomic(kaddr);
 335                                 return ret;
 336                         }
 337                 }
 338
 339                 sectors = bv->bv_len / bi->sector_size;
 340                 sector += sectors;
 341                 prot_buf += sectors * bi->tuple_size;
 342
 343                 kunmap_atomic(kaddr);
 344         }
 345         return ret;
 346 }
 347
 348 /**
 349  * bio_integrity_generate - Generate integrity metadata for a bio
 350  * @bio:        bio to generate integrity metadata for
 351  *
 352  * Description: Generates integrity metadata for a bio by calling the
 353  * block device's generation callback function.  The bio must have a
 354  * bip attached with enough room to accommodate the generated
 355  * integrity metadata.
 356  */
 357 static void bio_integrity_generate(struct bio *bio)
 358 {
 359         bio_integrity_generate_verify(bio, 1);
 360 }
 361
 362 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
 363 {
 364         if (bi)
 365                 return bi->tuple_size;
 366
 367         return 0;
 368 }
 369
 370 /**
 371  * bio_integrity_prep - Prepare bio for integrity I/O
 372  * @bio:        bio to prepare
 373  *
 374  * Description: Allocates a buffer for integrity metadata, maps the
 375  * pages and attaches them to a bio.  The bio must have data
 376  * direction, target device and start sector set priot to calling.  In
 377  * the WRITE case, integrity metadata will be generated using the
 378  * block device's integrity function.  In the READ case, the buffer
 379  * will be prepared for DMA and a suitable end_io handler set up.
 380  */
 381 int bio_integrity_prep(struct bio *bio)
 382 {
 383         struct bio_integrity_payload *bip;
 384         struct blk_integrity *bi;
 385         struct request_queue *q;
 386         void *buf;
 387         unsigned long start, end;
 388         unsigned int len, nr_pages;
 389         unsigned int bytes, offset, i;
 390         unsigned int sectors;
 391
 392         bi = bdev_get_integrity(bio->bi_bdev);
 393         q = bdev_get_queue(bio->bi_bdev);
 394         BUG_ON(bi == NULL);
 395         BUG_ON(bio_integrity(bio));
 396
 397         sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
 398
 399         /* Allocate kernel buffer for protection data */
 400         len = sectors * blk_integrity_tuple_size(bi);
 401         buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
 402         if (unlikely(buf == NULL)) {
 403                 printk(KERN_ERR "could not allocate integrity buffer\n");
 404                 return -ENOMEM;
 405         }
 406
 407         end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 408         start = ((unsigned long) buf) >> PAGE_SHIFT;
 409         nr_pages = end - start;
 410
 411         /* Allocate bio integrity payload and integrity vectors */
 412         bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
 413         if (unlikely(bip == NULL)) {
 414                 printk(KERN_ERR "could not allocate data integrity bioset\n");
 415                 kfree(buf);
 416                 return -EIO;
 417         }
 418
 419         bip->bip_owns_buf = 1;
 420         bip->bip_buf = buf;
 421         bip->bip_iter.bi_size = len;
 422         bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 423
 424         /* Map it */
 425         offset = offset_in_page(buf);
 426         for (i = 0 ; i < nr_pages ; i++) {
 427                 int ret;
 428                 bytes = PAGE_SIZE - offset;
 429
 430                 if (len <= 0)
 431                         break;
 432
 433                 if (bytes > len)
 434                         bytes = len;
 435
 436                 ret = bio_integrity_add_page(bio, virt_to_page(buf),
 437                                              bytes, offset);
 438
 439                 if (ret == 0)
 440                         return 0;
 441
 442                 if (ret < bytes)
 443                         break;
 444
 445                 buf += bytes;
 446                 len -= bytes;
 447                 offset = 0;
 448         }
 449
 450         /* Install custom I/O completion handler if read verify is enabled */
 451         if (bio_data_dir(bio) == READ) {
 452                 bip->bip_end_io = bio->bi_end_io;
 453                 bio->bi_end_io = bio_integrity_endio;
 454         }
 455
 456         /* Auto-generate integrity metadata if this is a write */
 457         if (bio_data_dir(bio) == WRITE)
 458                 bio_integrity_generate(bio);
 459
 460         return 0;
 461 }
 462 EXPORT_SYMBOL(bio_integrity_prep);
 463
 464 /**
 465  * bio_integrity_verify - Verify integrity metadata for a bio
 466  * @bio:        bio to verify
 467  *
 468  * Description: This function is called to verify the integrity of a
 469  * bio.  The data in the bio io_vec is compared to the integrity
 470  * metadata returned by the HBA.
 471  */
 472 static int bio_integrity_verify(struct bio *bio)
 473 {
 474         return bio_integrity_generate_verify(bio, 0);
 475 }
 476
 477 /**
 478  * bio_integrity_verify_fn - Integrity I/O completion worker
 479  * @work:       Work struct stored in bio to be verified
 480  *
 481  * Description: This workqueue function is called to complete a READ
 482  * request.  The function verifies the transferred integrity metadata
 483  * and then calls the original bio end_io function.
 484  */
 485 static void bio_integrity_verify_fn(struct work_struct *work)
 486 {
 487         struct bio_integrity_payload *bip =
 488                 container_of(work, struct bio_integrity_payload, bip_work);
 489         struct bio *bio = bip->bip_bio;
 490         int error;
 491
 492         error = bio_integrity_verify(bio);
 493
 494         /* Restore original bio completion handler */
 495         bio->bi_end_io = bip->bip_end_io;
 496         bio_endio_nodec(bio, error);
 497 }
 498
 499 /**
 500  * bio_integrity_endio - Integrity I/O completion function
 501  * @bio:        Protected bio
 502  * @error:      Pointer to errno
 503  *
 504  * Description: Completion for integrity I/O
 505  *
 506  * Normally I/O completion is done in interrupt context.  However,
 507  * verifying I/O integrity is a time-consuming task which must be run
 508  * in process context.  This function postpones completion
 509  * accordingly.
 510  */
 511 void bio_integrity_endio(struct bio *bio, int error)
 512 {
 513         struct bio_integrity_payload *bip = bio->bi_integrity;
 514
 515         BUG_ON(bip->bip_bio != bio);
 516
 517         /* In case of an I/O error there is no point in verifying the
 518          * integrity metadata.  Restore original bio end_io handler
 519          * and run it.
 520          */
 521         if (error) {
 522                 bio->bi_end_io = bip->bip_end_io;
 523                 bio_endio_nodec(bio, error);
 524
 525                 return;
 526         }
 527
 528         INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
 529         queue_work(kintegrityd_wq, &bip->bip_work);
 530 }
 531 EXPORT_SYMBOL(bio_integrity_endio);
 532
 533 /**
 534  * bio_integrity_advance - Advance integrity vector
 535  * @bio:        bio whose integrity vector to update
 536  * @bytes_done: number of data bytes that have been completed
 537  *
 538  * Description: This function calculates how many integrity bytes the
 539  * number of completed data bytes correspond to and advances the
 540  * integrity vector accordingly.
 541  */
 542 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
 543 {
 544         struct bio_integrity_payload *bip = bio->bi_integrity;
 545         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 546         unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
 547
 548         bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
 549 }
 550 EXPORT_SYMBOL(bio_integrity_advance);
 551
 552 /**
 553  * bio_integrity_trim - Trim integrity vector
 554  * @bio:        bio whose integrity vector to update
 555  * @offset:     offset to first data sector
 556  * @sectors:    number of data sectors
 557  *
 558  * Description: Used to trim the integrity vector in a cloned bio.
 559  * The ivec will be advanced corresponding to 'offset' data sectors
 560  * and the length will be truncated corresponding to 'len' data
 561  * sectors.
 562  */
 563 void bio_integrity_trim(struct bio *bio, unsigned int offset,
 564                         unsigned int sectors)
 565 {
 566         struct bio_integrity_payload *bip = bio->bi_integrity;
 567         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 568
 569         bio_integrity_advance(bio, offset << 9);
 570         bip->bip_iter.bi_size = bio_integrity_bytes(bi, sectors);
 571 }
 572 EXPORT_SYMBOL(bio_integrity_trim);
 573
 574 /**
 575  * bio_integrity_clone - Callback for cloning bios with integrity metadata
 576  * @bio:        New bio
 577  * @bio_src:    Original bio
 578  * @gfp_mask:   Memory allocation mask
 579  *
 580  * Description: Called to allocate a bip when cloning a bio
 581  */
 582 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 583                         gfp_t gfp_mask)
 584 {
 585         struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
 586         struct bio_integrity_payload *bip;
 587
 588         BUG_ON(bip_src == NULL);
 589
 590         bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
 591
 592         if (bip == NULL)
 593                 return -EIO;
 594
 595         memcpy(bip->bip_vec, bip_src->bip_vec,
 596                bip_src->bip_vcnt * sizeof(struct bio_vec));
 597
 598         bip->bip_vcnt = bip_src->bip_vcnt;
 599         bip->bip_iter = bip_src->bip_iter;
 600
 601         return 0;
 602 }
 603 EXPORT_SYMBOL(bio_integrity_clone);
 604
 605 int bioset_integrity_create(struct bio_set *bs, int pool_size)
 606 {
 607         if (bs->bio_integrity_pool)
 608                 return 0;
 609
 610         bs->bio_integrity_pool = mempool_create_slab_pool(pool_size, bip_slab);
 611         if (!bs->bio_integrity_pool)
 612                 return -1;
 613
 614         bs->bvec_integrity_pool = biovec_create_pool(pool_size);
 615         if (!bs->bvec_integrity_pool) {
 616                 mempool_destroy(bs->bio_integrity_pool);
 617                 return -1;
 618         }
 619
 620         return 0;
 621 }
 622 EXPORT_SYMBOL(bioset_integrity_create);
 623
 624 void bioset_integrity_free(struct bio_set *bs)
 625 {
 626         if (bs->bio_integrity_pool)
 627                 mempool_destroy(bs->bio_integrity_pool);
 628
 629         if (bs->bvec_integrity_pool)
 630                 mempool_destroy(bs->bvec_integrity_pool);
 631 }
 632 EXPORT_SYMBOL(bioset_integrity_free);
 633
 634 void __init bio_integrity_init(void)
 635 {
 636         /*
 637          * kintegrityd won't block much but may burn a lot of CPU cycles.
 638          * Make it highpri CPU intensive wq with max concurrency of 1.
 639          */
 640         kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
 641                                          WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
 642         if (!kintegrityd_wq)
 643                 panic("Failed to create kintegrityd\n");
 644
 645         bip_slab = kmem_cache_create("bio_integrity_payload",
 646                                      sizeof(struct bio_integrity_payload) +
 647                                      sizeof(struct bio_vec) * BIP_INLINE_VECS,
 648                                      0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 649         if (!bip_slab)
 650                 panic("Failed to create slab\n");
 651 }