include/linux/bio.h

   1 /*
   2  * 2.5 block I/O model
   3  *
   4  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public Licens
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  19  */
  20 #ifndef __LINUX_BIO_H
  21 #define __LINUX_BIO_H
  22
  23 #include <linux/highmem.h>
  24 #include <linux/mempool.h>
  25 #include <linux/ioprio.h>
  26
  27 #ifdef CONFIG_BLOCK
  28
  29 #include <asm/io.h>
  30
  31 #define BIO_DEBUG
  32
  33 #ifdef BIO_DEBUG
  34 #define BIO_BUG_ON      BUG_ON
  35 #else
  36 #define BIO_BUG_ON
  37 #endif
  38
  39 #define BIO_MAX_PAGES           256
  40 #define BIO_MAX_SIZE            (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
  41 #define BIO_MAX_SECTORS         (BIO_MAX_SIZE >> 9)
  42
  43 /*
  44  * was unsigned short, but we might as well be ready for > 64kB I/O pages
  45  */
  46 struct bio_vec {
  47         struct page     *bv_page;
  48         unsigned int    bv_len;
  49         unsigned int    bv_offset;
  50 };
  51
  52 struct bio_set;
  53 struct bio;
  54 struct bio_integrity_payload;
  55 typedef void (bio_end_io_t) (struct bio *, int);
  56 typedef void (bio_destructor_t) (struct bio *);
  57
  58 /*
  59  * main unit of I/O for the block layer and lower layers (ie drivers and
  60  * stacking drivers)
  61  */
  62 struct bio {
  63         sector_t                bi_sector;      /* device address in 512 byte
  64                                                    sectors */
  65         struct bio              *bi_next;       /* request queue link */
  66         struct block_device     *bi_bdev;
  67         unsigned long           bi_flags;       /* status, command, etc */
  68         unsigned long           bi_rw;          /* bottom bits READ/WRITE,
  69                                                  * top bits priority
  70                                                  */
  71
  72         unsigned short          bi_vcnt;        /* how many bio_vec's */
  73         unsigned short          bi_idx;         /* current index into bvl_vec */
  74
  75         /* Number of segments in this BIO after
  76          * physical address coalescing is performed.
  77          */
  78         unsigned int            bi_phys_segments;
  79
  80         unsigned int            bi_size;        /* residual I/O count */
  81
  82         /*
  83          * To keep track of the max segment size, we account for the
  84          * sizes of the first and last mergeable segments in this bio.
  85          */
  86         unsigned int            bi_seg_front_size;
  87         unsigned int            bi_seg_back_size;
  88
  89         unsigned int            bi_max_vecs;    /* max bvl_vecs we can hold */
  90
  91         unsigned int            bi_comp_cpu;    /* completion CPU */
  92
  93         struct bio_vec          *bi_io_vec;     /* the actual vec list */
  94
  95         bio_end_io_t            *bi_end_io;
  96         atomic_t                bi_cnt;         /* pin count */
  97
  98         void                    *bi_private;
  99 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 100         struct bio_integrity_payload *bi_integrity;  /* data integrity */
 101 #endif
 102
 103         bio_destructor_t        *bi_destructor; /* destructor */
 104 };
 105
 106 /*
 107  * bio flags
 108  */
 109 #define BIO_UPTODATE    0       /* ok after I/O completion */
 110 #define BIO_RW_BLOCK    1       /* RW_AHEAD set, and read/write would block */
 111 #define BIO_EOF         2       /* out-out-bounds error */
 112 #define BIO_SEG_VALID   3       /* bi_phys_segments valid */
 113 #define BIO_CLONED      4       /* doesn't own data */
 114 #define BIO_BOUNCED     5       /* bio is a bounce bio */
 115 #define BIO_USER_MAPPED 6       /* contains user pages */
 116 #define BIO_EOPNOTSUPP  7       /* not supported */
 117 #define BIO_CPU_AFFINE  8       /* complete bio on same CPU as submitted */
 118 #define BIO_NULL_MAPPED 9       /* contains invalid user pages */
 119 #define BIO_FS_INTEGRITY 10     /* fs owns integrity data, not block layer */
 120 #define bio_flagged(bio, flag)  ((bio)->bi_flags & (1 << (flag)))
 121
 122 /*
 123  * top 4 bits of bio flags indicate the pool this bio came from
 124  */
 125 #define BIO_POOL_BITS           (4)
 126 #define BIO_POOL_OFFSET         (BITS_PER_LONG - BIO_POOL_BITS)
 127 #define BIO_POOL_MASK           (1UL << BIO_POOL_OFFSET)
 128 #define BIO_POOL_IDX(bio)       ((bio)->bi_flags >> BIO_POOL_OFFSET)
 129
 130 /*
 131  * bio bi_rw flags
 132  *
 133  * bit 0 -- data direction
 134  *      If not set, bio is a read from device. If set, it's a write to device.
 135  * bit 1 -- rw-ahead when set
 136  * bit 2 -- barrier
 137  *      Insert a serialization point in the IO queue, forcing previously
 138  *      submitted IO to be completed before this oen is issued.
 139  * bit 3 -- synchronous I/O hint: the block layer will unplug immediately
 140  *      Note that this does NOT indicate that the IO itself is sync, just
 141  *      that the block layer will not postpone issue of this IO by plugging.
 142  * bit 4 -- metadata request
 143  *      Used for tracing to differentiate metadata and data IO. May also
 144  *      get some preferential treatment in the IO scheduler
 145  * bit 5 -- discard sectors
 146  *      Informs the lower level device that this range of sectors is no longer
 147  *      used by the file system and may thus be freed by the device. Used
 148  *      for flash based storage.
 149  * bit 6 -- fail fast device errors
 150  * bit 7 -- fail fast transport errors
 151  * bit 8 -- fail fast driver errors
 152  *      Don't want driver retries for any fast fail whatever the reason.
 153  */
 154 #define BIO_RW          0       /* Must match RW in req flags (blkdev.h) */
 155 #define BIO_RW_AHEAD    1       /* Must match FAILFAST in req flags */
 156 #define BIO_RW_BARRIER  2
 157 #define BIO_RW_SYNC     3
 158 #define BIO_RW_META     4
 159 #define BIO_RW_DISCARD  5
 160 #define BIO_RW_FAILFAST_DEV             6
 161 #define BIO_RW_FAILFAST_TRANSPORT       7
 162 #define BIO_RW_FAILFAST_DRIVER          8
 163
 164 /*
 165  * upper 16 bits of bi_rw define the io priority of this bio
 166  */
 167 #define BIO_PRIO_SHIFT  (8 * sizeof(unsigned long) - IOPRIO_BITS)
 168 #define bio_prio(bio)   ((bio)->bi_rw >> BIO_PRIO_SHIFT)
 169 #define bio_prio_valid(bio)     ioprio_valid(bio_prio(bio))
 170
 171 #define bio_set_prio(bio, prio)         do {                    \
 172         WARN_ON(prio >= (1 << IOPRIO_BITS));                    \
 173         (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);          \
 174         (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);     \
 175 } while (0)
 176
 177 /*
 178  * various member access, note that bio_data should of course not be used
 179  * on highmem page vectors
 180  */
 181 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
 182 #define bio_iovec(bio)          bio_iovec_idx((bio), (bio)->bi_idx)
 183 #define bio_page(bio)           bio_iovec((bio))->bv_page
 184 #define bio_offset(bio)         bio_iovec((bio))->bv_offset
 185 #define bio_segments(bio)       ((bio)->bi_vcnt - (bio)->bi_idx)
 186 #define bio_sectors(bio)        ((bio)->bi_size >> 9)
 187 #define bio_barrier(bio)        ((bio)->bi_rw & (1 << BIO_RW_BARRIER))
 188 #define bio_sync(bio)           ((bio)->bi_rw & (1 << BIO_RW_SYNC))
 189 #define bio_failfast_dev(bio)   ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DEV))
 190 #define bio_failfast_transport(bio)     \
 191         ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_TRANSPORT))
 192 #define bio_failfast_driver(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DRIVER))
 193 #define bio_rw_ahead(bio)       ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
 194 #define bio_rw_meta(bio)        ((bio)->bi_rw & (1 << BIO_RW_META))
 195 #define bio_discard(bio)        ((bio)->bi_rw & (1 << BIO_RW_DISCARD))
 196 #define bio_empty_barrier(bio)  (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
 197
 198 static inline unsigned int bio_cur_sectors(struct bio *bio)
 199 {
 200         if (bio->bi_vcnt)
 201                 return bio_iovec(bio)->bv_len >> 9;
 202         else /* dataless requests such as discard */
 203                 return bio->bi_size >> 9;
 204 }
 205
 206 static inline void *bio_data(struct bio *bio)
 207 {
 208         if (bio->bi_vcnt)
 209                 return page_address(bio_page(bio)) + bio_offset(bio);
 210
 211         return NULL;
 212 }
 213
 214 /*
 215  * will die
 216  */
 217 #define bio_to_phys(bio)        (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
 218 #define bvec_to_phys(bv)        (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
 219
 220 /*
 221  * queues that have highmem support enabled may still need to revert to
 222  * PIO transfers occasionally and thus map high pages temporarily. For
 223  * permanent PIO fall back, user is probably better off disabling highmem
 224  * I/O completely on that queue (see ide-dma for example)
 225  */
 226 #define __bio_kmap_atomic(bio, idx, kmtype)                             \
 227         (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) +    \
 228                 bio_iovec_idx((bio), (idx))->bv_offset)
 229
 230 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
 231
 232 /*
 233  * merge helpers etc
 234  */
 235
 236 #define __BVEC_END(bio)         bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
 237 #define __BVEC_START(bio)       bio_iovec_idx((bio), (bio)->bi_idx)
 238
 239 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
 240 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)     \
 241         ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 242
 243 /*
 244  * allow arch override, for eg virtualized architectures (put in asm/io.h)
 245  */
 246 #ifndef BIOVEC_PHYS_MERGEABLE
 247 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)       \
 248         __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
 249 #endif
 250
 251 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
 252         (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
 253 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
 254         __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
 255 #define BIO_SEG_BOUNDARY(q, b1, b2) \
 256         BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
 257
 258 #define bio_io_error(bio) bio_endio((bio), -EIO)
 259
 260 /*
 261  * drivers should not use the __ version unless they _really_ want to
 262  * run through the entire bio and not just pending pieces
 263  */
 264 #define __bio_for_each_segment(bvl, bio, i, start_idx)                  \
 265         for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);  \
 266              i < (bio)->bi_vcnt;                                        \
 267              bvl++, i++)
 268
 269 #define bio_for_each_segment(bvl, bio, i)                               \
 270         __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
 271
 272 /*
 273  * get a reference to a bio, so it won't disappear. the intended use is
 274  * something like:
 275  *
 276  * bio_get(bio);
 277  * submit_bio(rw, bio);
 278  * if (bio->bi_flags ...)
 279  *      do_something
 280  * bio_put(bio);
 281  *
 282  * without the bio_get(), it could potentially complete I/O before submit_bio
 283  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 284  * runs
 285  */
 286 #define bio_get(bio)    atomic_inc(&(bio)->bi_cnt)
 287
 288 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 289 /*
 290  * bio integrity payload
 291  */
 292 struct bio_integrity_payload {
 293         struct bio              *bip_bio;       /* parent bio */
 294         struct bio_vec          *bip_vec;       /* integrity data vector */
 295
 296         sector_t                bip_sector;     /* virtual start sector */
 297
 298         void                    *bip_buf;       /* generated integrity data */
 299         bio_end_io_t            *bip_end_io;    /* saved I/O completion fn */
 300
 301         int                     bip_error;      /* saved I/O error */
 302         unsigned int            bip_size;
 303
 304         unsigned short          bip_pool;       /* pool the ivec came from */
 305         unsigned short          bip_vcnt;       /* # of integrity bio_vecs */
 306         unsigned short          bip_idx;        /* current bip_vec index */
 307
 308         struct work_struct      bip_work;       /* I/O completion */
 309 };
 310 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 311
 312 /*
 313  * A bio_pair is used when we need to split a bio.
 314  * This can only happen for a bio that refers to just one
 315  * page of data, and in the unusual situation when the
 316  * page crosses a chunk/device boundary
 317  *
 318  * The address of the master bio is stored in bio1.bi_private
 319  * The address of the pool the pair was allocated from is stored
 320  *   in bio2.bi_private
 321  */
 322 struct bio_pair {
 323         struct bio                      bio1, bio2;
 324         struct bio_vec                  bv1, bv2;
 325 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 326         struct bio_integrity_payload    bip1, bip2;
 327         struct bio_vec                  iv1, iv2;
 328 #endif
 329         atomic_t                        cnt;
 330         int                             error;
 331 };
 332 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
 333 extern void bio_pair_release(struct bio_pair *dbio);
 334
 335 extern struct bio_set *bioset_create(int, int);
 336 extern void bioset_free(struct bio_set *);
 337
 338 extern struct bio *bio_alloc(gfp_t, int);
 339 extern struct bio *bio_kmalloc(gfp_t, int);
 340 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
 341 extern void bio_put(struct bio *);
 342 extern void bio_free(struct bio *, struct bio_set *);
 343
 344 extern void bio_endio(struct bio *, int);
 345 struct request_queue;
 346 extern int bio_phys_segments(struct request_queue *, struct bio *);
 347
 348 extern void __bio_clone(struct bio *, struct bio *);
 349 extern struct bio *bio_clone(struct bio *, gfp_t);
 350
 351 extern void bio_init(struct bio *);
 352
 353 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 354 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 355                            unsigned int, unsigned int);
 356 extern int bio_get_nr_vecs(struct block_device *);
 357 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
 358 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
 359                                 unsigned long, unsigned int, int, gfp_t);
 360 struct sg_iovec;
 361 struct rq_map_data;
 362 extern struct bio *bio_map_user_iov(struct request_queue *,
 363                                     struct block_device *,
 364                                     struct sg_iovec *, int, int, gfp_t);
 365 extern void bio_unmap_user(struct bio *);
 366 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
 367                                 gfp_t);
 368 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
 369                                  gfp_t, int);
 370 extern void bio_set_pages_dirty(struct bio *bio);
 371 extern void bio_check_pages_dirty(struct bio *bio);
 372 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
 373                                  unsigned long, unsigned int, int, gfp_t);
 374 extern struct bio *bio_copy_user_iov(struct request_queue *,
 375                                      struct rq_map_data *, struct sg_iovec *,
 376                                      int, int, gfp_t);
 377 extern int bio_uncopy_user(struct bio *);
 378 void zero_fill_bio(struct bio *bio);
 379 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
 380 extern unsigned int bvec_nr_vecs(unsigned short idx);
 381
 382 /*
 383  * Allow queuer to specify a completion CPU for this bio
 384  */
 385 static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
 386 {
 387         bio->bi_comp_cpu = cpu;
 388 }
 389
 390 /*
 391  * bio_set is used to allow other portions of the IO system to
 392  * allocate their own private memory pools for bio and iovec structures.
 393  * These memory pools in turn all allocate from the bio_slab
 394  * and the bvec_slabs[].
 395  */
 396 #define BIO_POOL_SIZE 2
 397 #define BIOVEC_NR_POOLS 6
 398
 399 struct bio_set {
 400         mempool_t *bio_pool;
 401 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 402         mempool_t *bio_integrity_pool;
 403 #endif
 404         mempool_t *bvec_pools[BIOVEC_NR_POOLS];
 405 };
 406
 407 struct biovec_slab {
 408         int nr_vecs;
 409         char *name;
 410         struct kmem_cache *slab;
 411 };
 412
 413 extern struct bio_set *fs_bio_set;
 414
 415 /*
 416  * a small number of entries is fine, not going to be performance critical.
 417  * basically we just need to survive
 418  */
 419 #define BIO_SPLIT_ENTRIES 2
 420
 421 #ifdef CONFIG_HIGHMEM
 422 /*
 423  * remember to add offset! and never ever reenable interrupts between a
 424  * bvec_kmap_irq and bvec_kunmap_irq!!
 425  *
 426  * This function MUST be inlined - it plays with the CPU interrupt flags.
 427  */
 428 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
 429 {
 430         unsigned long addr;
 431
 432         /*
 433          * might not be a highmem page, but the preempt/irq count
 434          * balancing is a lot nicer this way
 435          */
 436         local_irq_save(*flags);
 437         addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
 438
 439         BUG_ON(addr & ~PAGE_MASK);
 440
 441         return (char *) addr + bvec->bv_offset;
 442 }
 443
 444 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
 445 {
 446         unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
 447
 448         kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
 449         local_irq_restore(*flags);
 450 }
 451
 452 #else
 453 #define bvec_kmap_irq(bvec, flags)      (page_address((bvec)->bv_page) + (bvec)->bv_offset)
 454 #define bvec_kunmap_irq(buf, flags)     do { *(flags) = 0; } while (0)
 455 #endif
 456
 457 static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
 458                                    unsigned long *flags)
 459 {
 460         return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
 461 }
 462 #define __bio_kunmap_irq(buf, flags)    bvec_kunmap_irq(buf, flags)
 463
 464 #define bio_kmap_irq(bio, flags) \
 465         __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
 466 #define bio_kunmap_irq(buf,flags)       __bio_kunmap_irq(buf, flags)
 467
 468 /*
 469  * Check whether this bio carries any data or not. A NULL bio is allowed.
 470  */
 471 static inline int bio_has_data(struct bio *bio)
 472 {
 473         return bio && bio->bi_io_vec != NULL;
 474 }
 475
 476 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 477
 478 #define bip_vec_idx(bip, idx)   (&(bip->bip_vec[(idx)]))
 479 #define bip_vec(bip)            bip_vec_idx(bip, 0)
 480
 481 #define __bip_for_each_vec(bvl, bip, i, start_idx)                      \
 482         for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx);    \
 483              i < (bip)->bip_vcnt;                                       \
 484              bvl++, i++)
 485
 486 #define bip_for_each_vec(bvl, bip, i)                                   \
 487         __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
 488
 489 #define bio_integrity(bio) (bio->bi_integrity != NULL)
 490
 491 extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
 492 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
 493 extern void bio_integrity_free(struct bio *, struct bio_set *);
 494 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
 495 extern int bio_integrity_enabled(struct bio *bio);
 496 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
 497 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
 498 extern int bio_integrity_prep(struct bio *);
 499 extern void bio_integrity_endio(struct bio *, int);
 500 extern void bio_integrity_advance(struct bio *, unsigned int);
 501 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
 502 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
 503 extern int bio_integrity_clone(struct bio *, struct bio *, struct bio_set *);
 504 extern int bioset_integrity_create(struct bio_set *, int);
 505 extern void bioset_integrity_free(struct bio_set *);
 506 extern void bio_integrity_init_slab(void);
 507
 508 #else /* CONFIG_BLK_DEV_INTEGRITY */
 509
 510 #define bio_integrity(a)                (0)
 511 #define bioset_integrity_create(a, b)   (0)
 512 #define bio_integrity_prep(a)           (0)
 513 #define bio_integrity_enabled(a)        (0)
 514 #define bio_integrity_clone(a, b, c)    (0)
 515 #define bioset_integrity_free(a)        do { } while (0)
 516 #define bio_integrity_free(a, b)        do { } while (0)
 517 #define bio_integrity_endio(a, b)       do { } while (0)
 518 #define bio_integrity_advance(a, b)     do { } while (0)
 519 #define bio_integrity_trim(a, b, c)     do { } while (0)
 520 #define bio_integrity_split(a, b, c)    do { } while (0)
 521 #define bio_integrity_set_tag(a, b, c)  do { } while (0)
 522 #define bio_integrity_get_tag(a, b, c)  do { } while (0)
 523 #define bio_integrity_init_slab(a)      do { } while (0)
 524
 525 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 526
 527 #endif /* CONFIG_BLOCK */
 528 #endif /* __LINUX_BIO_H */