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  * Request flags.  For use in the cmd_flags field of struct request, and in
 142  * bi_rw of struct bio.  Note that some flags are only valid in either one.
 143  */
 144 enum rq_flag_bits {
 145         /* common flags */
 146         __REQ_WRITE,            /* not set, read. set, write */
 147         __REQ_FAILFAST_DEV,     /* no driver retries of device errors */
 148         __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
 149         __REQ_FAILFAST_DRIVER,  /* no driver retries of driver errors */
 150
 151         __REQ_HARDBARRIER,      /* may not be passed by drive either */
 152         __REQ_SYNC,             /* request is sync (sync write or read) */
 153         __REQ_META,             /* metadata io request */
 154         __REQ_DISCARD,          /* request to discard sectors */
 155         __REQ_NOIDLE,           /* don't anticipate more IO after this one */
 156
 157         /* bio only flags */
 158         __REQ_UNPLUG,           /* unplug the immediately after submission */
 159         __REQ_RAHEAD,           /* read ahead, can fail anytime */
 160
 161         /* request only flags */
 162         __REQ_SORTED,           /* elevator knows about this request */
 163         __REQ_SOFTBARRIER,      /* may not be passed by ioscheduler */
 164         __REQ_FUA,              /* forced unit access */
 165         __REQ_NOMERGE,          /* don't touch this for merging */
 166         __REQ_STARTED,          /* drive already may have started this one */
 167         __REQ_DONTPREP,         /* don't call prep for this one */
 168         __REQ_QUEUED,           /* uses queueing */
 169         __REQ_ELVPRIV,          /* elevator private data attached */
 170         __REQ_FAILED,           /* set if the request failed */
 171         __REQ_QUIET,            /* don't worry about errors */
 172         __REQ_PREEMPT,          /* set for "ide_preempt" requests */
 173         __REQ_ORDERED_COLOR,    /* is before or after barrier */
 174         __REQ_ALLOCED,          /* request came from our alloc pool */
 175         __REQ_COPY_USER,        /* contains copies of user pages */
 176         __REQ_INTEGRITY,        /* integrity metadata has been remapped */
 177         __REQ_IO_STAT,          /* account I/O stat */
 178         __REQ_MIXED_MERGE,      /* merge of different types, fail separately */
 179         __REQ_NR_BITS,          /* stops here */
 180 };
 181
 182 #define REQ_WRITE               (1 << __REQ_WRITE)
 183 #define REQ_FAILFAST_DEV        (1 << __REQ_FAILFAST_DEV)
 184 #define REQ_FAILFAST_TRANSPORT  (1 << __REQ_FAILFAST_TRANSPORT)
 185 #define REQ_FAILFAST_DRIVER     (1 << __REQ_FAILFAST_DRIVER)
 186 #define REQ_HARDBARRIER         (1 << __REQ_HARDBARRIER)
 187 #define REQ_SYNC                (1 << __REQ_SYNC)
 188 #define REQ_META                (1 << __REQ_META)
 189 #define REQ_DISCARD             (1 << __REQ_DISCARD)
 190 #define REQ_NOIDLE              (1 << __REQ_NOIDLE)
 191
 192 #define REQ_FAILFAST_MASK \
 193         (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 194 #define REQ_COMMON_MASK \
 195         (REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
 196          REQ_META| REQ_DISCARD | REQ_NOIDLE)
 197
 198 #define REQ_UNPLUG              (1 << __REQ_UNPLUG)
 199 #define REQ_RAHEAD              (1 << __REQ_RAHEAD)
 200
 201 #define REQ_SORTED              (1 << __REQ_SORTED)
 202 #define REQ_SOFTBARRIER         (1 << __REQ_SOFTBARRIER)
 203 #define REQ_FUA                 (1 << __REQ_FUA)
 204 #define REQ_NOMERGE             (1 << __REQ_NOMERGE)
 205 #define REQ_STARTED             (1 << __REQ_STARTED)
 206 #define REQ_DONTPREP            (1 << __REQ_DONTPREP)
 207 #define REQ_QUEUED              (1 << __REQ_QUEUED)
 208 #define REQ_ELVPRIV             (1 << __REQ_ELVPRIV)
 209 #define REQ_FAILED              (1 << __REQ_FAILED)
 210 #define REQ_QUIET               (1 << __REQ_QUIET)
 211 #define REQ_PREEMPT             (1 << __REQ_PREEMPT)
 212 #define REQ_ORDERED_COLOR       (1 << __REQ_ORDERED_COLOR)
 213 #define REQ_ALLOCED             (1 << __REQ_ALLOCED)
 214 #define REQ_COPY_USER           (1 << __REQ_COPY_USER)
 215 #define REQ_INTEGRITY           (1 << __REQ_INTEGRITY)
 216 #define REQ_IO_STAT             (1 << __REQ_IO_STAT)
 217 #define REQ_MIXED_MERGE         (1 << __REQ_MIXED_MERGE)
 218
 219 /*
 220  * upper 16 bits of bi_rw define the io priority of this bio
 221  */
 222 #define BIO_PRIO_SHIFT  (8 * sizeof(unsigned long) - IOPRIO_BITS)
 223 #define bio_prio(bio)   ((bio)->bi_rw >> BIO_PRIO_SHIFT)
 224 #define bio_prio_valid(bio)     ioprio_valid(bio_prio(bio))
 225
 226 #define bio_set_prio(bio, prio)         do {                    \
 227         WARN_ON(prio >= (1 << IOPRIO_BITS));                    \
 228         (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);          \
 229         (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);     \
 230 } while (0)
 231
 232 /*
 233  * various member access, note that bio_data should of course not be used
 234  * on highmem page vectors
 235  */
 236 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
 237 #define bio_iovec(bio)          bio_iovec_idx((bio), (bio)->bi_idx)
 238 #define bio_page(bio)           bio_iovec((bio))->bv_page
 239 #define bio_offset(bio)         bio_iovec((bio))->bv_offset
 240 #define bio_segments(bio)       ((bio)->bi_vcnt - (bio)->bi_idx)
 241 #define bio_sectors(bio)        ((bio)->bi_size >> 9)
 242 #define bio_empty_barrier(bio) \
 243         ((bio->bi_rw & REQ_HARDBARRIER) && \
 244          !bio_has_data(bio) && \
 245          !(bio->bi_rw & REQ_DISCARD))
 246
 247 static inline unsigned int bio_cur_bytes(struct bio *bio)
 248 {
 249         if (bio->bi_vcnt)
 250                 return bio_iovec(bio)->bv_len;
 251         else /* dataless requests such as discard */
 252                 return bio->bi_size;
 253 }
 254
 255 static inline void *bio_data(struct bio *bio)
 256 {
 257         if (bio->bi_vcnt)
 258                 return page_address(bio_page(bio)) + bio_offset(bio);
 259
 260         return NULL;
 261 }
 262
 263 static inline int bio_has_allocated_vec(struct bio *bio)
 264 {
 265         return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
 266 }
 267
 268 /*
 269  * will die
 270  */
 271 #define bio_to_phys(bio)        (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
 272 #define bvec_to_phys(bv)        (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
 273
 274 /*
 275  * queues that have highmem support enabled may still need to revert to
 276  * PIO transfers occasionally and thus map high pages temporarily. For
 277  * permanent PIO fall back, user is probably better off disabling highmem
 278  * I/O completely on that queue (see ide-dma for example)
 279  */
 280 #define __bio_kmap_atomic(bio, idx, kmtype)                             \
 281         (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) +    \
 282                 bio_iovec_idx((bio), (idx))->bv_offset)
 283
 284 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
 285
 286 /*
 287  * merge helpers etc
 288  */
 289
 290 #define __BVEC_END(bio)         bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
 291 #define __BVEC_START(bio)       bio_iovec_idx((bio), (bio)->bi_idx)
 292
 293 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
 294 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)     \
 295         ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 296
 297 /*
 298  * allow arch override, for eg virtualized architectures (put in asm/io.h)
 299  */
 300 #ifndef BIOVEC_PHYS_MERGEABLE
 301 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)       \
 302         __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
 303 #endif
 304
 305 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
 306         (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
 307 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
 308         __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
 309 #define BIO_SEG_BOUNDARY(q, b1, b2) \
 310         BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
 311
 312 #define bio_io_error(bio) bio_endio((bio), -EIO)
 313
 314 /*
 315  * drivers should not use the __ version unless they _really_ want to
 316  * run through the entire bio and not just pending pieces
 317  */
 318 #define __bio_for_each_segment(bvl, bio, i, start_idx)                  \
 319         for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);  \
 320              i < (bio)->bi_vcnt;                                        \
 321              bvl++, i++)
 322
 323 #define bio_for_each_segment(bvl, bio, i)                               \
 324         __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
 325
 326 /*
 327  * get a reference to a bio, so it won't disappear. the intended use is
 328  * something like:
 329  *
 330  * bio_get(bio);
 331  * submit_bio(rw, bio);
 332  * if (bio->bi_flags ...)
 333  *      do_something
 334  * bio_put(bio);
 335  *
 336  * without the bio_get(), it could potentially complete I/O before submit_bio
 337  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 338  * runs
 339  */
 340 #define bio_get(bio)    atomic_inc(&(bio)->bi_cnt)
 341
 342 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 343 /*
 344  * bio integrity payload
 345  */
 346 struct bio_integrity_payload {
 347         struct bio              *bip_bio;       /* parent bio */
 348
 349         sector_t                bip_sector;     /* virtual start sector */
 350
 351         void                    *bip_buf;       /* generated integrity data */
 352         bio_end_io_t            *bip_end_io;    /* saved I/O completion fn */
 353
 354         unsigned int            bip_size;
 355
 356         unsigned short          bip_slab;       /* slab the bip came from */
 357         unsigned short          bip_vcnt;       /* # of integrity bio_vecs */
 358         unsigned short          bip_idx;        /* current bip_vec index */
 359
 360         struct work_struct      bip_work;       /* I/O completion */
 361         struct bio_vec          bip_vec[0];     /* embedded bvec array */
 362 };
 363 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 364
 365 /*
 366  * A bio_pair is used when we need to split a bio.
 367  * This can only happen for a bio that refers to just one
 368  * page of data, and in the unusual situation when the
 369  * page crosses a chunk/device boundary
 370  *
 371  * The address of the master bio is stored in bio1.bi_private
 372  * The address of the pool the pair was allocated from is stored
 373  *   in bio2.bi_private
 374  */
 375 struct bio_pair {
 376         struct bio                      bio1, bio2;
 377         struct bio_vec                  bv1, bv2;
 378 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 379         struct bio_integrity_payload    bip1, bip2;
 380         struct bio_vec                  iv1, iv2;
 381 #endif
 382         atomic_t                        cnt;
 383         int                             error;
 384 };
 385 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
 386 extern void bio_pair_release(struct bio_pair *dbio);
 387
 388 extern struct bio_set *bioset_create(unsigned int, unsigned int);
 389 extern void bioset_free(struct bio_set *);
 390
 391 extern struct bio *bio_alloc(gfp_t, int);
 392 extern struct bio *bio_kmalloc(gfp_t, int);
 393 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
 394 extern void bio_put(struct bio *);
 395 extern void bio_free(struct bio *, struct bio_set *);
 396
 397 extern void bio_endio(struct bio *, int);
 398 struct request_queue;
 399 extern int bio_phys_segments(struct request_queue *, struct bio *);
 400
 401 extern void __bio_clone(struct bio *, struct bio *);
 402 extern struct bio *bio_clone(struct bio *, gfp_t);
 403
 404 extern void bio_init(struct bio *);
 405
 406 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 407 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 408                            unsigned int, unsigned int);
 409 extern int bio_get_nr_vecs(struct block_device *);
 410 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
 411 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
 412                                 unsigned long, unsigned int, int, gfp_t);
 413 struct sg_iovec;
 414 struct rq_map_data;
 415 extern struct bio *bio_map_user_iov(struct request_queue *,
 416                                     struct block_device *,
 417                                     struct sg_iovec *, int, int, gfp_t);
 418 extern void bio_unmap_user(struct bio *);
 419 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
 420                                 gfp_t);
 421 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
 422                                  gfp_t, int);
 423 extern void bio_set_pages_dirty(struct bio *bio);
 424 extern void bio_check_pages_dirty(struct bio *bio);
 425
 426 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 427 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 428 #endif
 429 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 430 extern void bio_flush_dcache_pages(struct bio *bi);
 431 #else
 432 static inline void bio_flush_dcache_pages(struct bio *bi)
 433 {
 434 }
 435 #endif
 436
 437 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
 438                                  unsigned long, unsigned int, int, gfp_t);
 439 extern struct bio *bio_copy_user_iov(struct request_queue *,
 440                                      struct rq_map_data *, struct sg_iovec *,
 441                                      int, int, gfp_t);
 442 extern int bio_uncopy_user(struct bio *);
 443 void zero_fill_bio(struct bio *bio);
 444 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
 445 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
 446 extern unsigned int bvec_nr_vecs(unsigned short idx);
 447
 448 /*
 449  * Allow queuer to specify a completion CPU for this bio
 450  */
 451 static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
 452 {
 453         bio->bi_comp_cpu = cpu;
 454 }
 455
 456 /*
 457  * bio_set is used to allow other portions of the IO system to
 458  * allocate their own private memory pools for bio and iovec structures.
 459  * These memory pools in turn all allocate from the bio_slab
 460  * and the bvec_slabs[].
 461  */
 462 #define BIO_POOL_SIZE 2
 463 #define BIOVEC_NR_POOLS 6
 464 #define BIOVEC_MAX_IDX  (BIOVEC_NR_POOLS - 1)
 465
 466 struct bio_set {
 467         struct kmem_cache *bio_slab;
 468         unsigned int front_pad;
 469
 470         mempool_t *bio_pool;
 471 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 472         mempool_t *bio_integrity_pool;
 473 #endif
 474         mempool_t *bvec_pool;
 475 };
 476
 477 struct biovec_slab {
 478         int nr_vecs;
 479         char *name;
 480         struct kmem_cache *slab;
 481 };
 482
 483 extern struct bio_set *fs_bio_set;
 484 extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
 485
 486 /*
 487  * a small number of entries is fine, not going to be performance critical.
 488  * basically we just need to survive
 489  */
 490 #define BIO_SPLIT_ENTRIES 2
 491
 492 #ifdef CONFIG_HIGHMEM
 493 /*
 494  * remember never ever reenable interrupts between a bvec_kmap_irq and
 495  * bvec_kunmap_irq!
 496  */
 497 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
 498 {
 499         unsigned long addr;
 500
 501         /*
 502          * might not be a highmem page, but the preempt/irq count
 503          * balancing is a lot nicer this way
 504          */
 505         local_irq_save(*flags);
 506         addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
 507
 508         BUG_ON(addr & ~PAGE_MASK);
 509
 510         return (char *) addr + bvec->bv_offset;
 511 }
 512
 513 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
 514 {
 515         unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
 516
 517         kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
 518         local_irq_restore(*flags);
 519 }
 520
 521 #else
 522 #define bvec_kmap_irq(bvec, flags)      (page_address((bvec)->bv_page) + (bvec)->bv_offset)
 523 #define bvec_kunmap_irq(buf, flags)     do { *(flags) = 0; } while (0)
 524 #endif
 525
 526 static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
 527                                    unsigned long *flags)
 528 {
 529         return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
 530 }
 531 #define __bio_kunmap_irq(buf, flags)    bvec_kunmap_irq(buf, flags)
 532
 533 #define bio_kmap_irq(bio, flags) \
 534         __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
 535 #define bio_kunmap_irq(buf,flags)       __bio_kunmap_irq(buf, flags)
 536
 537 /*
 538  * Check whether this bio carries any data or not. A NULL bio is allowed.
 539  */
 540 static inline int bio_has_data(struct bio *bio)
 541 {
 542         return bio && bio->bi_io_vec != NULL;
 543 }
 544
 545 /*
 546  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
 547  *
 548  * A bio_list anchors a singly-linked list of bios chained through the bi_next
 549  * member of the bio.  The bio_list also caches the last list member to allow
 550  * fast access to the tail.
 551  */
 552 struct bio_list {
 553         struct bio *head;
 554         struct bio *tail;
 555 };
 556
 557 static inline int bio_list_empty(const struct bio_list *bl)
 558 {
 559         return bl->head == NULL;
 560 }
 561
 562 static inline void bio_list_init(struct bio_list *bl)
 563 {
 564         bl->head = bl->tail = NULL;
 565 }
 566
 567 #define bio_list_for_each(bio, bl) \
 568         for (bio = (bl)->head; bio; bio = bio->bi_next)
 569
 570 static inline unsigned bio_list_size(const struct bio_list *bl)
 571 {
 572         unsigned sz = 0;
 573         struct bio *bio;
 574
 575         bio_list_for_each(bio, bl)
 576                 sz++;
 577
 578         return sz;
 579 }
 580
 581 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
 582 {
 583         bio->bi_next = NULL;
 584
 585         if (bl->tail)
 586                 bl->tail->bi_next = bio;
 587         else
 588                 bl->head = bio;
 589
 590         bl->tail = bio;
 591 }
 592
 593 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
 594 {
 595         bio->bi_next = bl->head;
 596
 597         bl->head = bio;
 598
 599         if (!bl->tail)
 600                 bl->tail = bio;
 601 }
 602
 603 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
 604 {
 605         if (!bl2->head)
 606                 return;
 607
 608         if (bl->tail)
 609                 bl->tail->bi_next = bl2->head;
 610         else
 611                 bl->head = bl2->head;
 612
 613         bl->tail = bl2->tail;
 614 }
 615
 616 static inline void bio_list_merge_head(struct bio_list *bl,
 617                                        struct bio_list *bl2)
 618 {
 619         if (!bl2->head)
 620                 return;
 621
 622         if (bl->head)
 623                 bl2->tail->bi_next = bl->head;
 624         else
 625                 bl->tail = bl2->tail;
 626
 627         bl->head = bl2->head;
 628 }
 629
 630 static inline struct bio *bio_list_peek(struct bio_list *bl)
 631 {
 632         return bl->head;
 633 }
 634
 635 static inline struct bio *bio_list_pop(struct bio_list *bl)
 636 {
 637         struct bio *bio = bl->head;
 638
 639         if (bio) {
 640                 bl->head = bl->head->bi_next;
 641                 if (!bl->head)
 642                         bl->tail = NULL;
 643
 644                 bio->bi_next = NULL;
 645         }
 646
 647         return bio;
 648 }
 649
 650 static inline struct bio *bio_list_get(struct bio_list *bl)
 651 {
 652         struct bio *bio = bl->head;
 653
 654         bl->head = bl->tail = NULL;
 655
 656         return bio;
 657 }
 658
 659 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 660
 661 #define bip_vec_idx(bip, idx)   (&(bip->bip_vec[(idx)]))
 662 #define bip_vec(bip)            bip_vec_idx(bip, 0)
 663
 664 #define __bip_for_each_vec(bvl, bip, i, start_idx)                      \
 665         for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx);    \
 666              i < (bip)->bip_vcnt;                                       \
 667              bvl++, i++)
 668
 669 #define bip_for_each_vec(bvl, bip, i)                                   \
 670         __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
 671
 672 #define bio_integrity(bio) (bio->bi_integrity != NULL)
 673
 674 extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
 675 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
 676 extern void bio_integrity_free(struct bio *, struct bio_set *);
 677 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
 678 extern int bio_integrity_enabled(struct bio *bio);
 679 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
 680 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
 681 extern int bio_integrity_prep(struct bio *);
 682 extern void bio_integrity_endio(struct bio *, int);
 683 extern void bio_integrity_advance(struct bio *, unsigned int);
 684 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
 685 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
 686 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t, struct bio_set *);
 687 extern int bioset_integrity_create(struct bio_set *, int);
 688 extern void bioset_integrity_free(struct bio_set *);
 689 extern void bio_integrity_init(void);
 690
 691 #else /* CONFIG_BLK_DEV_INTEGRITY */
 692
 693 #define bio_integrity(a)                (0)
 694 #define bioset_integrity_create(a, b)   (0)
 695 #define bio_integrity_prep(a)           (0)
 696 #define bio_integrity_enabled(a)        (0)
 697 #define bio_integrity_clone(a, b, c, d) (0)
 698 #define bioset_integrity_free(a)        do { } while (0)
 699 #define bio_integrity_free(a, b)        do { } while (0)
 700 #define bio_integrity_endio(a, b)       do { } while (0)
 701 #define bio_integrity_advance(a, b)     do { } while (0)
 702 #define bio_integrity_trim(a, b, c)     do { } while (0)
 703 #define bio_integrity_split(a, b, c)    do { } while (0)
 704 #define bio_integrity_set_tag(a, b, c)  do { } while (0)
 705 #define bio_integrity_get_tag(a, b, c)  do { } while (0)
 706 #define bio_integrity_init(a)           do { } while (0)
 707
 708 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 709
 710 #endif /* CONFIG_BLOCK */
 711 #endif /* __LINUX_BIO_H */