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         atomic_t                bi_cnt;         /* pin count */
  94
  95         struct bio_vec          *bi_io_vec;     /* the actual vec list */
  96
  97         bio_end_io_t            *bi_end_io;
  98
  99         void                    *bi_private;
 100 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 101         struct bio_integrity_payload *bi_integrity;  /* data integrity */
 102 #endif
 103
 104         bio_destructor_t        *bi_destructor; /* destructor */
 105
 106         /*
 107          * We can inline a number of vecs at the end of the bio, to avoid
 108          * double allocations for a small number of bio_vecs. This member
 109          * MUST obviously be kept at the very end of the bio.
 110          */
 111         struct bio_vec          bi_inline_vecs[0];
 112 };
 113
 114 /*
 115  * bio flags
 116  */
 117 #define BIO_UPTODATE    0       /* ok after I/O completion */
 118 #define BIO_RW_BLOCK    1       /* RW_AHEAD set, and read/write would block */
 119 #define BIO_EOF         2       /* out-out-bounds error */
 120 #define BIO_SEG_VALID   3       /* bi_phys_segments valid */
 121 #define BIO_CLONED      4       /* doesn't own data */
 122 #define BIO_BOUNCED     5       /* bio is a bounce bio */
 123 #define BIO_USER_MAPPED 6       /* contains user pages */
 124 #define BIO_EOPNOTSUPP  7       /* not supported */
 125 #define BIO_CPU_AFFINE  8       /* complete bio on same CPU as submitted */
 126 #define BIO_NULL_MAPPED 9       /* contains invalid user pages */
 127 #define BIO_FS_INTEGRITY 10     /* fs owns integrity data, not block layer */
 128 #define BIO_QUIET       11      /* Make BIO Quiet */
 129 #define bio_flagged(bio, flag)  ((bio)->bi_flags & (1 << (flag)))
 130
 131 /*
 132  * top 4 bits of bio flags indicate the pool this bio came from
 133  */
 134 #define BIO_POOL_BITS           (4)
 135 #define BIO_POOL_NONE           ((1UL << BIO_POOL_BITS) - 1)
 136 #define BIO_POOL_OFFSET         (BITS_PER_LONG - BIO_POOL_BITS)
 137 #define BIO_POOL_MASK           (1UL << BIO_POOL_OFFSET)
 138 #define BIO_POOL_IDX(bio)       ((bio)->bi_flags >> BIO_POOL_OFFSET)
 139
 140 /*
 141  * bio bi_rw flags
 142  *
 143  * bit 0 -- data direction
 144  *      If not set, bio is a read from device. If set, it's a write to device.
 145  * bit 1 -- fail fast device errors
 146  * bit 2 -- fail fast transport errors
 147  * bit 3 -- fail fast driver errors
 148  * bit 4 -- rw-ahead when set
 149  * bit 5 -- barrier
 150  *      Insert a serialization point in the IO queue, forcing previously
 151  *      submitted IO to be completed before this one is issued.
 152  * bit 6 -- synchronous I/O hint.
 153  * bit 7 -- Unplug the device immediately after submitting this bio.
 154  * bit 8 -- metadata request
 155  *      Used for tracing to differentiate metadata and data IO. May also
 156  *      get some preferential treatment in the IO scheduler
 157  * bit 9 -- discard sectors
 158  *      Informs the lower level device that this range of sectors is no longer
 159  *      used by the file system and may thus be freed by the device. Used
 160  *      for flash based storage.
 161  *      Don't want driver retries for any fast fail whatever the reason.
 162  * bit 10 -- Tell the IO scheduler not to wait for more requests after this
 163         one has been submitted, even if it is a SYNC request.
 164  */
 165 enum bio_rw_flags {
 166         BIO_RW,
 167         BIO_RW_FAILFAST_DEV,
 168         BIO_RW_FAILFAST_TRANSPORT,
 169         BIO_RW_FAILFAST_DRIVER,
 170         /* above flags must match REQ_* */
 171         BIO_RW_AHEAD,
 172         BIO_RW_BARRIER,
 173         BIO_RW_SYNCIO,
 174         BIO_RW_UNPLUG,
 175         BIO_RW_META,
 176         BIO_RW_DISCARD,
 177         BIO_RW_NOIDLE,
 178 };
 179
 180 #define bio_rw_flagged(bio, flag)       ((bio)->bi_rw & (1 << (flag)))
 181
 182 /*
 183  * Old defines, these should eventually be replaced by direct usage of
 184  * bio_rw_flagged()
 185  */
 186 #define bio_barrier(bio)        bio_rw_flagged(bio, BIO_RW_BARRIER)
 187 #define bio_sync(bio)           bio_rw_flagged(bio, BIO_RW_SYNCIO)
 188 #define bio_unplug(bio)         bio_rw_flagged(bio, BIO_RW_UNPLUG)
 189 #define bio_failfast_dev(bio)   bio_rw_flagged(bio, BIO_RW_FAILFAST_DEV)
 190 #define bio_failfast_transport(bio)     \
 191                 bio_rw_flagged(bio, BIO_RW_FAILFAST_TRANSPORT)
 192 #define bio_failfast_driver(bio)        \
 193                 bio_rw_flagged(bio, BIO_RW_FAILFAST_DRIVER)
 194 #define bio_rw_ahead(bio)       bio_rw_flagged(bio, BIO_RW_AHEAD)
 195 #define bio_rw_meta(bio)        bio_rw_flagged(bio, BIO_RW_META)
 196 #define bio_discard(bio)        bio_rw_flagged(bio, BIO_RW_DISCARD)
 197 #define bio_noidle(bio)         bio_rw_flagged(bio, BIO_RW_NOIDLE)
 198
 199 /*
 200  * upper 16 bits of bi_rw define the io priority of this bio
 201  */
 202 #define BIO_PRIO_SHIFT  (8 * sizeof(unsigned long) - IOPRIO_BITS)
 203 #define bio_prio(bio)   ((bio)->bi_rw >> BIO_PRIO_SHIFT)
 204 #define bio_prio_valid(bio)     ioprio_valid(bio_prio(bio))
 205
 206 #define bio_set_prio(bio, prio)         do {                    \
 207         WARN_ON(prio >= (1 << IOPRIO_BITS));                    \
 208         (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);          \
 209         (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);     \
 210 } while (0)
 211
 212 /*
 213  * various member access, note that bio_data should of course not be used
 214  * on highmem page vectors
 215  */
 216 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
 217 #define bio_iovec(bio)          bio_iovec_idx((bio), (bio)->bi_idx)
 218 #define bio_page(bio)           bio_iovec((bio))->bv_page
 219 #define bio_offset(bio)         bio_iovec((bio))->bv_offset
 220 #define bio_segments(bio)       ((bio)->bi_vcnt - (bio)->bi_idx)
 221 #define bio_sectors(bio)        ((bio)->bi_size >> 9)
 222 #define bio_empty_barrier(bio)  (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
 223
 224 static inline unsigned int bio_cur_bytes(struct bio *bio)
 225 {
 226         if (bio->bi_vcnt)
 227                 return bio_iovec(bio)->bv_len;
 228         else /* dataless requests such as discard */
 229                 return bio->bi_size;
 230 }
 231
 232 static inline void *bio_data(struct bio *bio)
 233 {
 234         if (bio->bi_vcnt)
 235                 return page_address(bio_page(bio)) + bio_offset(bio);
 236
 237         return NULL;
 238 }
 239
 240 static inline int bio_has_allocated_vec(struct bio *bio)
 241 {
 242         return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
 243 }
 244
 245 /*
 246  * will die
 247  */
 248 #define bio_to_phys(bio)        (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
 249 #define bvec_to_phys(bv)        (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
 250
 251 /*
 252  * queues that have highmem support enabled may still need to revert to
 253  * PIO transfers occasionally and thus map high pages temporarily. For
 254  * permanent PIO fall back, user is probably better off disabling highmem
 255  * I/O completely on that queue (see ide-dma for example)
 256  */
 257 #define __bio_kmap_atomic(bio, idx, kmtype)                             \
 258         (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) +    \
 259                 bio_iovec_idx((bio), (idx))->bv_offset)
 260
 261 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
 262
 263 /*
 264  * merge helpers etc
 265  */
 266
 267 #define __BVEC_END(bio)         bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
 268 #define __BVEC_START(bio)       bio_iovec_idx((bio), (bio)->bi_idx)
 269
 270 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
 271 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)     \
 272         ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 273
 274 /*
 275  * allow arch override, for eg virtualized architectures (put in asm/io.h)
 276  */
 277 #ifndef BIOVEC_PHYS_MERGEABLE
 278 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)       \
 279         __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
 280 #endif
 281
 282 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
 283         (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
 284 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
 285         __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
 286 #define BIO_SEG_BOUNDARY(q, b1, b2) \
 287         BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
 288
 289 #define bio_io_error(bio) bio_endio((bio), -EIO)
 290
 291 /*
 292  * drivers should not use the __ version unless they _really_ want to
 293  * run through the entire bio and not just pending pieces
 294  */
 295 #define __bio_for_each_segment(bvl, bio, i, start_idx)                  \
 296         for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);  \
 297              i < (bio)->bi_vcnt;                                        \
 298              bvl++, i++)
 299
 300 #define bio_for_each_segment(bvl, bio, i)                               \
 301         __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
 302
 303 /*
 304  * get a reference to a bio, so it won't disappear. the intended use is
 305  * something like:
 306  *
 307  * bio_get(bio);
 308  * submit_bio(rw, bio);
 309  * if (bio->bi_flags ...)
 310  *      do_something
 311  * bio_put(bio);
 312  *
 313  * without the bio_get(), it could potentially complete I/O before submit_bio
 314  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 315  * runs
 316  */
 317 #define bio_get(bio)    atomic_inc(&(bio)->bi_cnt)
 318
 319 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 320 /*
 321  * bio integrity payload
 322  */
 323 struct bio_integrity_payload {
 324         struct bio              *bip_bio;       /* parent bio */
 325
 326         sector_t                bip_sector;     /* virtual start sector */
 327
 328         void                    *bip_buf;       /* generated integrity data */
 329         bio_end_io_t            *bip_end_io;    /* saved I/O completion fn */
 330
 331         unsigned int            bip_size;
 332
 333         unsigned short          bip_slab;       /* slab the bip came from */
 334         unsigned short          bip_vcnt;       /* # of integrity bio_vecs */
 335         unsigned short          bip_idx;        /* current bip_vec index */
 336
 337         struct work_struct      bip_work;       /* I/O completion */
 338         struct bio_vec          bip_vec[0];     /* embedded bvec array */
 339 };
 340 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 341
 342 /*
 343  * A bio_pair is used when we need to split a bio.
 344  * This can only happen for a bio that refers to just one
 345  * page of data, and in the unusual situation when the
 346  * page crosses a chunk/device boundary
 347  *
 348  * The address of the master bio is stored in bio1.bi_private
 349  * The address of the pool the pair was allocated from is stored
 350  *   in bio2.bi_private
 351  */
 352 struct bio_pair {
 353         struct bio                      bio1, bio2;
 354         struct bio_vec                  bv1, bv2;
 355 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 356         struct bio_integrity_payload    bip1, bip2;
 357         struct bio_vec                  iv1, iv2;
 358 #endif
 359         atomic_t                        cnt;
 360         int                             error;
 361 };
 362 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
 363 extern void bio_pair_release(struct bio_pair *dbio);
 364
 365 extern struct bio_set *bioset_create(unsigned int, unsigned int);
 366 extern void bioset_free(struct bio_set *);
 367
 368 extern struct bio *bio_alloc(gfp_t, int);
 369 extern struct bio *bio_kmalloc(gfp_t, int);
 370 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
 371 extern void bio_put(struct bio *);
 372 extern void bio_free(struct bio *, struct bio_set *);
 373
 374 extern void bio_endio(struct bio *, int);
 375 struct request_queue;
 376 extern int bio_phys_segments(struct request_queue *, struct bio *);
 377
 378 extern void __bio_clone(struct bio *, struct bio *);
 379 extern struct bio *bio_clone(struct bio *, gfp_t);
 380
 381 extern void bio_init(struct bio *);
 382
 383 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 384 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 385                            unsigned int, unsigned int);
 386 extern int bio_get_nr_vecs(struct block_device *);
 387 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
 388 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
 389                                 unsigned long, unsigned int, int, gfp_t);
 390 struct sg_iovec;
 391 struct rq_map_data;
 392 extern struct bio *bio_map_user_iov(struct request_queue *,
 393                                     struct block_device *,
 394                                     struct sg_iovec *, int, int, gfp_t);
 395 extern void bio_unmap_user(struct bio *);
 396 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
 397                                 gfp_t);
 398 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
 399                                  gfp_t, int);
 400 extern void bio_set_pages_dirty(struct bio *bio);
 401 extern void bio_check_pages_dirty(struct bio *bio);
 402 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
 403                                  unsigned long, unsigned int, int, gfp_t);
 404 extern struct bio *bio_copy_user_iov(struct request_queue *,
 405                                      struct rq_map_data *, struct sg_iovec *,
 406                                      int, int, gfp_t);
 407 extern int bio_uncopy_user(struct bio *);
 408 void zero_fill_bio(struct bio *bio);
 409 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
 410 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
 411 extern unsigned int bvec_nr_vecs(unsigned short idx);
 412
 413 /*
 414  * Allow queuer to specify a completion CPU for this bio
 415  */
 416 static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
 417 {
 418         bio->bi_comp_cpu = cpu;
 419 }
 420
 421 /*
 422  * bio_set is used to allow other portions of the IO system to
 423  * allocate their own private memory pools for bio and iovec structures.
 424  * These memory pools in turn all allocate from the bio_slab
 425  * and the bvec_slabs[].
 426  */
 427 #define BIO_POOL_SIZE 2
 428 #define BIOVEC_NR_POOLS 6
 429 #define BIOVEC_MAX_IDX  (BIOVEC_NR_POOLS - 1)
 430
 431 struct bio_set {
 432         struct kmem_cache *bio_slab;
 433         unsigned int front_pad;
 434
 435         mempool_t *bio_pool;
 436 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 437         mempool_t *bio_integrity_pool;
 438 #endif
 439         mempool_t *bvec_pool;
 440 };
 441
 442 struct biovec_slab {
 443         int nr_vecs;
 444         char *name;
 445         struct kmem_cache *slab;
 446 };
 447
 448 extern struct bio_set *fs_bio_set;
 449 extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
 450
 451 /*
 452  * a small number of entries is fine, not going to be performance critical.
 453  * basically we just need to survive
 454  */
 455 #define BIO_SPLIT_ENTRIES 2
 456
 457 #ifdef CONFIG_HIGHMEM
 458 /*
 459  * remember never ever reenable interrupts between a bvec_kmap_irq and
 460  * bvec_kunmap_irq!
 461  *
 462  * This function MUST be inlined - it plays with the CPU interrupt flags.
 463  */
 464 static __always_inline char *bvec_kmap_irq(struct bio_vec *bvec,
 465                 unsigned long *flags)
 466 {
 467         unsigned long addr;
 468
 469         /*
 470          * might not be a highmem page, but the preempt/irq count
 471          * balancing is a lot nicer this way
 472          */
 473         local_irq_save(*flags);
 474         addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
 475
 476         BUG_ON(addr & ~PAGE_MASK);
 477
 478         return (char *) addr + bvec->bv_offset;
 479 }
 480
 481 static __always_inline void bvec_kunmap_irq(char *buffer,
 482                 unsigned long *flags)
 483 {
 484         unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
 485
 486         kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
 487         local_irq_restore(*flags);
 488 }
 489
 490 #else
 491 #define bvec_kmap_irq(bvec, flags)      (page_address((bvec)->bv_page) + (bvec)->bv_offset)
 492 #define bvec_kunmap_irq(buf, flags)     do { *(flags) = 0; } while (0)
 493 #endif
 494
 495 static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
 496                                    unsigned long *flags)
 497 {
 498         return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
 499 }
 500 #define __bio_kunmap_irq(buf, flags)    bvec_kunmap_irq(buf, flags)
 501
 502 #define bio_kmap_irq(bio, flags) \
 503         __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
 504 #define bio_kunmap_irq(buf,flags)       __bio_kunmap_irq(buf, flags)
 505
 506 /*
 507  * Check whether this bio carries any data or not. A NULL bio is allowed.
 508  */
 509 static inline int bio_has_data(struct bio *bio)
 510 {
 511         return bio && bio->bi_io_vec != NULL;
 512 }
 513
 514 /*
 515  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
 516  *
 517  * A bio_list anchors a singly-linked list of bios chained through the bi_next
 518  * member of the bio.  The bio_list also caches the last list member to allow
 519  * fast access to the tail.
 520  */
 521 struct bio_list {
 522         struct bio *head;
 523         struct bio *tail;
 524 };
 525
 526 static inline int bio_list_empty(const struct bio_list *bl)
 527 {
 528         return bl->head == NULL;
 529 }
 530
 531 static inline void bio_list_init(struct bio_list *bl)
 532 {
 533         bl->head = bl->tail = NULL;
 534 }
 535
 536 #define bio_list_for_each(bio, bl) \
 537         for (bio = (bl)->head; bio; bio = bio->bi_next)
 538
 539 static inline unsigned bio_list_size(const struct bio_list *bl)
 540 {
 541         unsigned sz = 0;
 542         struct bio *bio;
 543
 544         bio_list_for_each(bio, bl)
 545                 sz++;
 546
 547         return sz;
 548 }
 549
 550 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
 551 {
 552         bio->bi_next = NULL;
 553
 554         if (bl->tail)
 555                 bl->tail->bi_next = bio;
 556         else
 557                 bl->head = bio;
 558
 559         bl->tail = bio;
 560 }
 561
 562 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
 563 {
 564         bio->bi_next = bl->head;
 565
 566         bl->head = bio;
 567
 568         if (!bl->tail)
 569                 bl->tail = bio;
 570 }
 571
 572 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
 573 {
 574         if (!bl2->head)
 575                 return;
 576
 577         if (bl->tail)
 578                 bl->tail->bi_next = bl2->head;
 579         else
 580                 bl->head = bl2->head;
 581
 582         bl->tail = bl2->tail;
 583 }
 584
 585 static inline void bio_list_merge_head(struct bio_list *bl,
 586                                        struct bio_list *bl2)
 587 {
 588         if (!bl2->head)
 589                 return;
 590
 591         if (bl->head)
 592                 bl2->tail->bi_next = bl->head;
 593         else
 594                 bl->tail = bl2->tail;
 595
 596         bl->head = bl2->head;
 597 }
 598
 599 static inline struct bio *bio_list_peek(struct bio_list *bl)
 600 {
 601         return bl->head;
 602 }
 603
 604 static inline struct bio *bio_list_pop(struct bio_list *bl)
 605 {
 606         struct bio *bio = bl->head;
 607
 608         if (bio) {
 609                 bl->head = bl->head->bi_next;
 610                 if (!bl->head)
 611                         bl->tail = NULL;
 612
 613                 bio->bi_next = NULL;
 614         }
 615
 616         return bio;
 617 }
 618
 619 static inline struct bio *bio_list_get(struct bio_list *bl)
 620 {
 621         struct bio *bio = bl->head;
 622
 623         bl->head = bl->tail = NULL;
 624
 625         return bio;
 626 }
 627
 628 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 629
 630 #define bip_vec_idx(bip, idx)   (&(bip->bip_vec[(idx)]))
 631 #define bip_vec(bip)            bip_vec_idx(bip, 0)
 632
 633 #define __bip_for_each_vec(bvl, bip, i, start_idx)                      \
 634         for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx);    \
 635              i < (bip)->bip_vcnt;                                       \
 636              bvl++, i++)
 637
 638 #define bip_for_each_vec(bvl, bip, i)                                   \
 639         __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
 640
 641 #define bio_integrity(bio) (bio->bi_integrity != NULL)
 642
 643 extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
 644 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
 645 extern void bio_integrity_free(struct bio *, struct bio_set *);
 646 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
 647 extern int bio_integrity_enabled(struct bio *bio);
 648 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
 649 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
 650 extern int bio_integrity_prep(struct bio *);
 651 extern void bio_integrity_endio(struct bio *, int);
 652 extern void bio_integrity_advance(struct bio *, unsigned int);
 653 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
 654 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
 655 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t, struct bio_set *);
 656 extern int bioset_integrity_create(struct bio_set *, int);
 657 extern void bioset_integrity_free(struct bio_set *);
 658 extern void bio_integrity_init(void);
 659
 660 #else /* CONFIG_BLK_DEV_INTEGRITY */
 661
 662 #define bio_integrity(a)                (0)
 663 #define bioset_integrity_create(a, b)   (0)
 664 #define bio_integrity_prep(a)           (0)
 665 #define bio_integrity_enabled(a)        (0)
 666 #define bio_integrity_clone(a, b, c, d) (0)
 667 #define bioset_integrity_free(a)        do { } while (0)
 668 #define bio_integrity_free(a, b)        do { } while (0)
 669 #define bio_integrity_endio(a, b)       do { } while (0)
 670 #define bio_integrity_advance(a, b)     do { } while (0)
 671 #define bio_integrity_trim(a, b, c)     do { } while (0)
 672 #define bio_integrity_split(a, b, c)    do { } while (0)
 673 #define bio_integrity_set_tag(a, b, c)  do { } while (0)
 674 #define bio_integrity_get_tag(a, b, c)  do { } while (0)
 675 #define bio_integrity_init(a)           do { } while (0)
 676
 677 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 678
 679 #endif /* CONFIG_BLOCK */
 680 #endif /* __LINUX_BIO_H */