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 #include <linux/bug.h>
  27
  28 #ifdef CONFIG_BLOCK
  29
  30 #include <asm/io.h>
  31
  32 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
  33 #include <linux/blk_types.h>
  34
  35 #define BIO_DEBUG
  36
  37 #ifdef BIO_DEBUG
  38 #define BIO_BUG_ON      BUG_ON
  39 #else
  40 #define BIO_BUG_ON
  41 #endif
  42
  43 #define BIO_MAX_PAGES           256
  44 #define BIO_MAX_SIZE            (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
  45 #define BIO_MAX_SECTORS         (BIO_MAX_SIZE >> 9)
  46
  47 /*
  48  * upper 16 bits of bi_rw define the io priority of this bio
  49  */
  50 #define BIO_PRIO_SHIFT  (8 * sizeof(unsigned long) - IOPRIO_BITS)
  51 #define bio_prio(bio)   ((bio)->bi_rw >> BIO_PRIO_SHIFT)
  52 #define bio_prio_valid(bio)     ioprio_valid(bio_prio(bio))
  53
  54 #define bio_set_prio(bio, prio)         do {                    \
  55         WARN_ON(prio >= (1 << IOPRIO_BITS));                    \
  56         (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);          \
  57         (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);     \
  58 } while (0)
  59
  60 /*
  61  * various member access, note that bio_data should of course not be used
  62  * on highmem page vectors
  63  */
  64 #define __bvec_iter_bvec(bvec, iter)    (&(bvec)[(iter).bi_idx])
  65
  66 #define bvec_iter_page(bvec, iter)                              \
  67         (__bvec_iter_bvec((bvec), (iter))->bv_page)
  68
  69 #define bvec_iter_len(bvec, iter)                               \
  70         min((iter).bi_size,                                     \
  71             __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
  72
  73 #define bvec_iter_offset(bvec, iter)                            \
  74         (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
  75
  76 #define bvec_iter_bvec(bvec, iter)                              \
  77 ((struct bio_vec) {                                             \
  78         .bv_page        = bvec_iter_page((bvec), (iter)),       \
  79         .bv_len         = bvec_iter_len((bvec), (iter)),        \
  80         .bv_offset      = bvec_iter_offset((bvec), (iter)),     \
  81 })
  82
  83 #define bio_iter_iovec(bio, iter)                               \
  84         bvec_iter_bvec((bio)->bi_io_vec, (iter))
  85
  86 #define bio_iter_page(bio, iter)                                \
  87         bvec_iter_page((bio)->bi_io_vec, (iter))
  88 #define bio_iter_len(bio, iter)                                 \
  89         bvec_iter_len((bio)->bi_io_vec, (iter))
  90 #define bio_iter_offset(bio, iter)                              \
  91         bvec_iter_offset((bio)->bi_io_vec, (iter))
  92
  93 #define bio_page(bio)           bio_iter_page((bio), (bio)->bi_iter)
  94 #define bio_offset(bio)         bio_iter_offset((bio), (bio)->bi_iter)
  95 #define bio_iovec(bio)          bio_iter_iovec((bio), (bio)->bi_iter)
  96
  97 #define bio_multiple_segments(bio)                              \
  98         ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
  99 #define bio_sectors(bio)        ((bio)->bi_iter.bi_size >> 9)
 100 #define bio_end_sector(bio)     ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
 101
 102 /*
 103  * Check whether this bio carries any data or not. A NULL bio is allowed.
 104  */
 105 static inline bool bio_has_data(struct bio *bio)
 106 {
 107         if (bio &&
 108             bio->bi_iter.bi_size &&
 109             !(bio->bi_rw & REQ_DISCARD))
 110                 return true;
 111
 112         return false;
 113 }
 114
 115 static inline bool bio_is_rw(struct bio *bio)
 116 {
 117         if (!bio_has_data(bio))
 118                 return false;
 119
 120         if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
 121                 return false;
 122
 123         return true;
 124 }
 125
 126 static inline bool bio_mergeable(struct bio *bio)
 127 {
 128         if (bio->bi_rw & REQ_NOMERGE_FLAGS)
 129                 return false;
 130
 131         return true;
 132 }
 133
 134 static inline unsigned int bio_cur_bytes(struct bio *bio)
 135 {
 136         if (bio_has_data(bio))
 137                 return bio_iovec(bio).bv_len;
 138         else /* dataless requests such as discard */
 139                 return bio->bi_iter.bi_size;
 140 }
 141
 142 static inline void *bio_data(struct bio *bio)
 143 {
 144         if (bio_has_data(bio))
 145                 return page_address(bio_page(bio)) + bio_offset(bio);
 146
 147         return NULL;
 148 }
 149
 150 /*
 151  * will die
 152  */
 153 #define bio_to_phys(bio)        (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
 154 #define bvec_to_phys(bv)        (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
 155
 156 /*
 157  * queues that have highmem support enabled may still need to revert to
 158  * PIO transfers occasionally and thus map high pages temporarily. For
 159  * permanent PIO fall back, user is probably better off disabling highmem
 160  * I/O completely on that queue (see ide-dma for example)
 161  */
 162 #define __bio_kmap_atomic(bio, iter)                            \
 163         (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) +   \
 164                 bio_iter_iovec((bio), (iter)).bv_offset)
 165
 166 #define __bio_kunmap_atomic(addr)       kunmap_atomic(addr)
 167
 168 /*
 169  * merge helpers etc
 170  */
 171
 172 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
 173 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)     \
 174         ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 175
 176 /*
 177  * allow arch override, for eg virtualized architectures (put in asm/io.h)
 178  */
 179 #ifndef BIOVEC_PHYS_MERGEABLE
 180 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)       \
 181         __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
 182 #endif
 183
 184 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
 185         (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
 186 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
 187         __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
 188
 189 #define bio_io_error(bio) bio_endio((bio), -EIO)
 190
 191 /*
 192  * drivers should _never_ use the all version - the bio may have been split
 193  * before it got to the driver and the driver won't own all of it
 194  */
 195 #define bio_for_each_segment_all(bvl, bio, i)                           \
 196         for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
 197
 198 static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
 199                                      unsigned bytes)
 200 {
 201         WARN_ONCE(bytes > iter->bi_size,
 202                   "Attempted to advance past end of bvec iter\n");
 203
 204         while (bytes) {
 205                 unsigned len = min(bytes, bvec_iter_len(bv, *iter));
 206
 207                 bytes -= len;
 208                 iter->bi_size -= len;
 209                 iter->bi_bvec_done += len;
 210
 211                 if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
 212                         iter->bi_bvec_done = 0;
 213                         iter->bi_idx++;
 214                 }
 215         }
 216 }
 217
 218 #define for_each_bvec(bvl, bio_vec, iter, start)                        \
 219         for ((iter) = start;                                            \
 220              (bvl) = bvec_iter_bvec((bio_vec), (iter)),                 \
 221                 (iter).bi_size;                                         \
 222              bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
 223
 224
 225 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
 226                                     unsigned bytes)
 227 {
 228         iter->bi_sector += bytes >> 9;
 229
 230         if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
 231                 iter->bi_size -= bytes;
 232         else
 233                 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
 234 }
 235
 236 #define __bio_for_each_segment(bvl, bio, iter, start)                   \
 237         for (iter = (start);                                            \
 238              (iter).bi_size &&                                          \
 239                 ((bvl = bio_iter_iovec((bio), (iter))), 1);             \
 240              bio_advance_iter((bio), &(iter), (bvl).bv_len))
 241
 242 #define bio_for_each_segment(bvl, bio, iter)                            \
 243         __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
 244
 245 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
 246
 247 static inline unsigned bio_segments(struct bio *bio)
 248 {
 249         unsigned segs = 0;
 250         struct bio_vec bv;
 251         struct bvec_iter iter;
 252
 253         /*
 254          * We special case discard/write same, because they interpret bi_size
 255          * differently:
 256          */
 257
 258         if (bio->bi_rw & REQ_DISCARD)
 259                 return 1;
 260
 261         if (bio->bi_rw & REQ_WRITE_SAME)
 262                 return 1;
 263
 264         bio_for_each_segment(bv, bio, iter)
 265                 segs++;
 266
 267         return segs;
 268 }
 269
 270 /*
 271  * get a reference to a bio, so it won't disappear. the intended use is
 272  * something like:
 273  *
 274  * bio_get(bio);
 275  * submit_bio(rw, bio);
 276  * if (bio->bi_flags ...)
 277  *      do_something
 278  * bio_put(bio);
 279  *
 280  * without the bio_get(), it could potentially complete I/O before submit_bio
 281  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 282  * runs
 283  */
 284 #define bio_get(bio)    atomic_inc(&(bio)->bi_cnt)
 285
 286 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 287 /*
 288  * bio integrity payload
 289  */
 290 struct bio_integrity_payload {
 291         struct bio              *bip_bio;       /* parent bio */
 292
 293         struct bvec_iter        bip_iter;
 294
 295         /* kill - should just use bip_vec */
 296         void                    *bip_buf;       /* generated integrity data */
 297
 298         bio_end_io_t            *bip_end_io;    /* saved I/O completion fn */
 299
 300         unsigned short          bip_slab;       /* slab the bip came from */
 301         unsigned short          bip_vcnt;       /* # of integrity bio_vecs */
 302         unsigned                bip_owns_buf:1; /* should free bip_buf */
 303
 304         struct work_struct      bip_work;       /* I/O completion */
 305
 306         struct bio_vec          *bip_vec;
 307         struct bio_vec          bip_inline_vecs[0];/* embedded bvec array */
 308 };
 309 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 310
 311 extern void bio_trim(struct bio *bio, int offset, int size);
 312 extern struct bio *bio_split(struct bio *bio, int sectors,
 313                              gfp_t gfp, struct bio_set *bs);
 314
 315 /**
 316  * bio_next_split - get next @sectors from a bio, splitting if necessary
 317  * @bio:        bio to split
 318  * @sectors:    number of sectors to split from the front of @bio
 319  * @gfp:        gfp mask
 320  * @bs:         bio set to allocate from
 321  *
 322  * Returns a bio representing the next @sectors of @bio - if the bio is smaller
 323  * than @sectors, returns the original bio unchanged.
 324  */
 325 static inline struct bio *bio_next_split(struct bio *bio, int sectors,
 326                                          gfp_t gfp, struct bio_set *bs)
 327 {
 328         if (sectors >= bio_sectors(bio))
 329                 return bio;
 330
 331         return bio_split(bio, sectors, gfp, bs);
 332 }
 333
 334 extern struct bio_set *bioset_create(unsigned int, unsigned int);
 335 extern void bioset_free(struct bio_set *);
 336 extern mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries);
 337
 338 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
 339 extern void bio_put(struct bio *);
 340
 341 extern void __bio_clone_fast(struct bio *, struct bio *);
 342 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
 343 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
 344
 345 extern struct bio_set *fs_bio_set;
 346 unsigned int bio_integrity_tag_size(struct bio *bio);
 347
 348 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 349 {
 350         return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
 351 }
 352
 353 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
 354 {
 355         return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
 356 }
 357
 358 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 359 {
 360         return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
 361 }
 362
 363 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
 364 {
 365         return bio_clone_bioset(bio, gfp_mask, NULL);
 366
 367 }
 368
 369 extern void bio_endio(struct bio *, int);
 370 extern void bio_endio_nodec(struct bio *, int);
 371 struct request_queue;
 372 extern int bio_phys_segments(struct request_queue *, struct bio *);
 373
 374 extern int submit_bio_wait(int rw, struct bio *bio);
 375 extern void bio_advance(struct bio *, unsigned);
 376
 377 extern void bio_init(struct bio *);
 378 extern void bio_reset(struct bio *);
 379 void bio_chain(struct bio *, struct bio *);
 380
 381 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 382 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 383                            unsigned int, unsigned int);
 384 extern int bio_get_nr_vecs(struct block_device *);
 385 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
 386                                 unsigned long, unsigned int, int, gfp_t);
 387 struct sg_iovec;
 388 struct rq_map_data;
 389 extern struct bio *bio_map_user_iov(struct request_queue *,
 390                                     struct block_device *,
 391                                     struct sg_iovec *, int, int, gfp_t);
 392 extern void bio_unmap_user(struct bio *);
 393 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
 394                                 gfp_t);
 395 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
 396                                  gfp_t, int);
 397 extern void bio_set_pages_dirty(struct bio *bio);
 398 extern void bio_check_pages_dirty(struct bio *bio);
 399
 400 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 401 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 402 #endif
 403 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 404 extern void bio_flush_dcache_pages(struct bio *bi);
 405 #else
 406 static inline void bio_flush_dcache_pages(struct bio *bi)
 407 {
 408 }
 409 #endif
 410
 411 extern void bio_copy_data(struct bio *dst, struct bio *src);
 412 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
 413
 414 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
 415                                  unsigned long, unsigned int, int, gfp_t);
 416 extern struct bio *bio_copy_user_iov(struct request_queue *,
 417                                      struct rq_map_data *, struct sg_iovec *,
 418                                      int, int, gfp_t);
 419 extern int bio_uncopy_user(struct bio *);
 420 void zero_fill_bio(struct bio *bio);
 421 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
 422 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
 423 extern unsigned int bvec_nr_vecs(unsigned short idx);
 424
 425 #ifdef CONFIG_BLK_CGROUP
 426 int bio_associate_current(struct bio *bio);
 427 void bio_disassociate_task(struct bio *bio);
 428 #else   /* CONFIG_BLK_CGROUP */
 429 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
 430 static inline void bio_disassociate_task(struct bio *bio) { }
 431 #endif  /* CONFIG_BLK_CGROUP */
 432
 433 #ifdef CONFIG_HIGHMEM
 434 /*
 435  * remember never ever reenable interrupts between a bvec_kmap_irq and
 436  * bvec_kunmap_irq!
 437  */
 438 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
 439 {
 440         unsigned long addr;
 441
 442         /*
 443          * might not be a highmem page, but the preempt/irq count
 444          * balancing is a lot nicer this way
 445          */
 446         local_irq_save(*flags);
 447         addr = (unsigned long) kmap_atomic(bvec->bv_page);
 448
 449         BUG_ON(addr & ~PAGE_MASK);
 450
 451         return (char *) addr + bvec->bv_offset;
 452 }
 453
 454 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
 455 {
 456         unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
 457
 458         kunmap_atomic((void *) ptr);
 459         local_irq_restore(*flags);
 460 }
 461
 462 #else
 463 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
 464 {
 465         return page_address(bvec->bv_page) + bvec->bv_offset;
 466 }
 467
 468 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
 469 {
 470         *flags = 0;
 471 }
 472 #endif
 473
 474 static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
 475                                    unsigned long *flags)
 476 {
 477         return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
 478 }
 479 #define __bio_kunmap_irq(buf, flags)    bvec_kunmap_irq(buf, flags)
 480
 481 #define bio_kmap_irq(bio, flags) \
 482         __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
 483 #define bio_kunmap_irq(buf,flags)       __bio_kunmap_irq(buf, flags)
 484
 485 /*
 486  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
 487  *
 488  * A bio_list anchors a singly-linked list of bios chained through the bi_next
 489  * member of the bio.  The bio_list also caches the last list member to allow
 490  * fast access to the tail.
 491  */
 492 struct bio_list {
 493         struct bio *head;
 494         struct bio *tail;
 495 };
 496
 497 static inline int bio_list_empty(const struct bio_list *bl)
 498 {
 499         return bl->head == NULL;
 500 }
 501
 502 static inline void bio_list_init(struct bio_list *bl)
 503 {
 504         bl->head = bl->tail = NULL;
 505 }
 506
 507 #define BIO_EMPTY_LIST  { NULL, NULL }
 508
 509 #define bio_list_for_each(bio, bl) \
 510         for (bio = (bl)->head; bio; bio = bio->bi_next)
 511
 512 static inline unsigned bio_list_size(const struct bio_list *bl)
 513 {
 514         unsigned sz = 0;
 515         struct bio *bio;
 516
 517         bio_list_for_each(bio, bl)
 518                 sz++;
 519
 520         return sz;
 521 }
 522
 523 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
 524 {
 525         bio->bi_next = NULL;
 526
 527         if (bl->tail)
 528                 bl->tail->bi_next = bio;
 529         else
 530                 bl->head = bio;
 531
 532         bl->tail = bio;
 533 }
 534
 535 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
 536 {
 537         bio->bi_next = bl->head;
 538
 539         bl->head = bio;
 540
 541         if (!bl->tail)
 542                 bl->tail = bio;
 543 }
 544
 545 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
 546 {
 547         if (!bl2->head)
 548                 return;
 549
 550         if (bl->tail)
 551                 bl->tail->bi_next = bl2->head;
 552         else
 553                 bl->head = bl2->head;
 554
 555         bl->tail = bl2->tail;
 556 }
 557
 558 static inline void bio_list_merge_head(struct bio_list *bl,
 559                                        struct bio_list *bl2)
 560 {
 561         if (!bl2->head)
 562                 return;
 563
 564         if (bl->head)
 565                 bl2->tail->bi_next = bl->head;
 566         else
 567                 bl->tail = bl2->tail;
 568
 569         bl->head = bl2->head;
 570 }
 571
 572 static inline struct bio *bio_list_peek(struct bio_list *bl)
 573 {
 574         return bl->head;
 575 }
 576
 577 static inline struct bio *bio_list_pop(struct bio_list *bl)
 578 {
 579         struct bio *bio = bl->head;
 580
 581         if (bio) {
 582                 bl->head = bl->head->bi_next;
 583                 if (!bl->head)
 584                         bl->tail = NULL;
 585
 586                 bio->bi_next = NULL;
 587         }
 588
 589         return bio;
 590 }
 591
 592 static inline struct bio *bio_list_get(struct bio_list *bl)
 593 {
 594         struct bio *bio = bl->head;
 595
 596         bl->head = bl->tail = NULL;
 597
 598         return bio;
 599 }
 600
 601 /*
 602  * bio_set is used to allow other portions of the IO system to
 603  * allocate their own private memory pools for bio and iovec structures.
 604  * These memory pools in turn all allocate from the bio_slab
 605  * and the bvec_slabs[].
 606  */
 607 #define BIO_POOL_SIZE 2
 608 #define BIOVEC_NR_POOLS 6
 609 #define BIOVEC_MAX_IDX  (BIOVEC_NR_POOLS - 1)
 610
 611 struct bio_set {
 612         struct kmem_cache *bio_slab;
 613         unsigned int front_pad;
 614
 615         mempool_t *bio_pool;
 616         mempool_t *bvec_pool;
 617 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 618         mempool_t *bio_integrity_pool;
 619         mempool_t *bvec_integrity_pool;
 620 #endif
 621
 622         /*
 623          * Deadlock avoidance for stacking block drivers: see comments in
 624          * bio_alloc_bioset() for details
 625          */
 626         spinlock_t              rescue_lock;
 627         struct bio_list         rescue_list;
 628         struct work_struct      rescue_work;
 629         struct workqueue_struct *rescue_workqueue;
 630 };
 631
 632 struct biovec_slab {
 633         int nr_vecs;
 634         char *name;
 635         struct kmem_cache *slab;
 636 };
 637
 638 /*
 639  * a small number of entries is fine, not going to be performance critical.
 640  * basically we just need to survive
 641  */
 642 #define BIO_SPLIT_ENTRIES 2
 643
 644 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 645
 646
 647
 648 #define bip_vec_idx(bip, idx)   (&(bip->bip_vec[(idx)]))
 649
 650 #define bip_for_each_vec(bvl, bip, iter)                                \
 651         for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
 652
 653 #define bio_for_each_integrity_vec(_bvl, _bio, _iter)                   \
 654         for_each_bio(_bio)                                              \
 655                 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
 656
 657 #define bio_integrity(bio) (bio->bi_integrity != NULL)
 658
 659 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
 660 extern void bio_integrity_free(struct bio *);
 661 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
 662 extern int bio_integrity_enabled(struct bio *bio);
 663 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
 664 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
 665 extern int bio_integrity_prep(struct bio *);
 666 extern void bio_integrity_endio(struct bio *, int);
 667 extern void bio_integrity_advance(struct bio *, unsigned int);
 668 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
 669 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
 670 extern int bioset_integrity_create(struct bio_set *, int);
 671 extern void bioset_integrity_free(struct bio_set *);
 672 extern void bio_integrity_init(void);
 673
 674 #else /* CONFIG_BLK_DEV_INTEGRITY */
 675
 676 static inline int bio_integrity(struct bio *bio)
 677 {
 678         return 0;
 679 }
 680
 681 static inline int bio_integrity_enabled(struct bio *bio)
 682 {
 683         return 0;
 684 }
 685
 686 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
 687 {
 688         return 0;
 689 }
 690
 691 static inline void bioset_integrity_free (struct bio_set *bs)
 692 {
 693         return;
 694 }
 695
 696 static inline int bio_integrity_prep(struct bio *bio)
 697 {
 698         return 0;
 699 }
 700
 701 static inline void bio_integrity_free(struct bio *bio)
 702 {
 703         return;
 704 }
 705
 706 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 707                                       gfp_t gfp_mask)
 708 {
 709         return 0;
 710 }
 711
 712 static inline void bio_integrity_advance(struct bio *bio,
 713                                          unsigned int bytes_done)
 714 {
 715         return;
 716 }
 717
 718 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
 719                                       unsigned int sectors)
 720 {
 721         return;
 722 }
 723
 724 static inline void bio_integrity_init(void)
 725 {
 726         return;
 727 }
 728
 729 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 730
 731 #endif /* CONFIG_BLOCK */
 732 #endif /* __LINUX_BIO_H */