LCOV - code coverage report
Current view: top level - include/linux - bio.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 3 3 100.0 %
Date: 2017-01-25 Functions: 0 0 -

          Line data    Source code
       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           1 : typedef void (bio_end_io_t) (struct bio *, int);
      56           1 : typedef void (bio_destructor_t) (struct bio *);
      57           1 : 
      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             : /*
     181             :  * First four bits must match between bio->bi_rw and rq->cmd_flags, make
     182             :  * that explicit here.
     183             :  */
     184             : #define BIO_RW_RQ_MASK          0xf
     185             : 
     186             : static inline bool bio_rw_flagged(struct bio *bio, enum bio_rw_flags flag)
     187             : {
     188             :         return (bio->bi_rw & (1 << flag)) != 0;
     189             : }
     190             : 
     191             : /*
     192             :  * upper 16 bits of bi_rw define the io priority of this bio
     193             :  */
     194             : #define BIO_PRIO_SHIFT  (8 * sizeof(unsigned long) - IOPRIO_BITS)
     195             : #define bio_prio(bio)   ((bio)->bi_rw >> BIO_PRIO_SHIFT)
     196             : #define bio_prio_valid(bio)     ioprio_valid(bio_prio(bio))
     197             : 
     198             : #define bio_set_prio(bio, prio)         do {                    \
     199             :         WARN_ON(prio >= (1 << IOPRIO_BITS));                   \
     200             :         (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);             \
     201             :         (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);    \
     202             : } while (0)
     203             : 
     204             : /*
     205             :  * various member access, note that bio_data should of course not be used
     206             :  * on highmem page vectors
     207             :  */
     208             : #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
     209             : #define bio_iovec(bio)          bio_iovec_idx((bio), (bio)->bi_idx)
     210             : #define bio_page(bio)           bio_iovec((bio))->bv_page
     211             : #define bio_offset(bio)         bio_iovec((bio))->bv_offset
     212             : #define bio_segments(bio)       ((bio)->bi_vcnt - (bio)->bi_idx)
     213             : #define bio_sectors(bio)        ((bio)->bi_size >> 9)
     214             : #define bio_empty_barrier(bio)  (bio_rw_flagged(bio, BIO_RW_BARRIER) && !bio_has_data(bio) && !bio_rw_flagged(bio, BIO_RW_DISCARD))
     215             : 
     216             : static inline unsigned int bio_cur_bytes(struct bio *bio)
     217             : {
     218             :         if (bio->bi_vcnt)
     219             :                 return bio_iovec(bio)->bv_len;
     220             :         else /* dataless requests such as discard */
     221             :                 return bio->bi_size;
     222             : }
     223             : 
     224             : static inline void *bio_data(struct bio *bio)
     225             : {
     226             :         if (bio->bi_vcnt)
     227             :                 return page_address(bio_page(bio)) + bio_offset(bio);
     228             : 
     229             :         return NULL;
     230             : }
     231             : 
     232             : static inline int bio_has_allocated_vec(struct bio *bio)
     233             : {
     234             :         return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
     235             : }
     236             : 
     237             : /*
     238             :  * will die
     239             :  */
     240             : #define bio_to_phys(bio)        (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
     241             : #define bvec_to_phys(bv)        (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
     242             : 
     243             : /*
     244             :  * queues that have highmem support enabled may still need to revert to
     245             :  * PIO transfers occasionally and thus map high pages temporarily. For
     246             :  * permanent PIO fall back, user is probably better off disabling highmem
     247             :  * I/O completely on that queue (see ide-dma for example)
     248             :  */
     249             : #define __bio_kmap_atomic(bio, idx, kmtype)                             \
     250             :         (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
     251             :                 bio_iovec_idx((bio), (idx))->bv_offset)
     252             : 
     253             : #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
     254             : 
     255             : /*
     256             :  * merge helpers etc
     257             :  */
     258             : 
     259             : #define __BVEC_END(bio)         bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
     260             : #define __BVEC_START(bio)       bio_iovec_idx((bio), (bio)->bi_idx)
     261             : 
     262             : /* Default implementation of BIOVEC_PHYS_MERGEABLE */
     263             : #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)     \
     264             :         ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
     265             : 
     266             : /*
     267             :  * allow arch override, for eg virtualized architectures (put in asm/io.h)
     268             :  */
     269             : #ifndef BIOVEC_PHYS_MERGEABLE
     270             : #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)       \
     271             :         __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
     272             : #endif
     273             : 
     274             : #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
     275             :         (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
     276             : #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
     277             :         __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
     278             : #define BIO_SEG_BOUNDARY(q, b1, b2) \
     279             :         BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
     280             : 
     281             : #define bio_io_error(bio) bio_endio((bio), -EIO)
     282             : 
     283             : /*
     284             :  * drivers should not use the __ version unless they _really_ want to
     285             :  * run through the entire bio and not just pending pieces
     286             :  */
     287             : #define __bio_for_each_segment(bvl, bio, i, start_idx)                  \
     288             :         for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);  \
     289             :              i < (bio)->bi_vcnt;                                  \
     290             :              bvl++, i++)
     291             : 
     292             : #define bio_for_each_segment(bvl, bio, i)                               \
     293             :         __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
     294             : 
     295             : /*
     296             :  * get a reference to a bio, so it won't disappear. the intended use is
     297             :  * something like:
     298             :  *
     299             :  * bio_get(bio);
     300             :  * submit_bio(rw, bio);
     301             :  * if (bio->bi_flags ...)
     302             :  *      do_something
     303             :  * bio_put(bio);
     304             :  *
     305             :  * without the bio_get(), it could potentially complete I/O before submit_bio
     306             :  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
     307             :  * runs
     308             :  */
     309             : #define bio_get(bio)    atomic_inc(&(bio)->bi_cnt)
     310             : 
     311             : #if defined(CONFIG_BLK_DEV_INTEGRITY)
     312             : /*
     313             :  * bio integrity payload
     314             :  */
     315             : struct bio_integrity_payload {
     316             :         struct bio              *bip_bio;       /* parent bio */
     317             : 
     318             :         sector_t                bip_sector;     /* virtual start sector */
     319             : 
     320             :         void                    *bip_buf;       /* generated integrity data */
     321             :         bio_end_io_t            *bip_end_io;    /* saved I/O completion fn */
     322             : 
     323             :         unsigned int            bip_size;
     324             : 
     325             :         unsigned short          bip_slab;       /* slab the bip came from */
     326             :         unsigned short          bip_vcnt;       /* # of integrity bio_vecs */
     327             :         unsigned short          bip_idx;        /* current bip_vec index */
     328             : 
     329             :         struct work_struct      bip_work;       /* I/O completion */
     330             :         struct bio_vec          bip_vec[0];     /* embedded bvec array */
     331             : };
     332             : #endif /* CONFIG_BLK_DEV_INTEGRITY */
     333             : 
     334             : /*
     335             :  * A bio_pair is used when we need to split a bio.
     336             :  * This can only happen for a bio that refers to just one
     337             :  * page of data, and in the unusual situation when the
     338             :  * page crosses a chunk/device boundary
     339             :  *
     340             :  * The address of the master bio is stored in bio1.bi_private
     341             :  * The address of the pool the pair was allocated from is stored
     342             :  *   in bio2.bi_private
     343             :  */
     344             : struct bio_pair {
     345             :         struct bio                      bio1, bio2;
     346             :         struct bio_vec                  bv1, bv2;
     347             : #if defined(CONFIG_BLK_DEV_INTEGRITY)
     348             :         struct bio_integrity_payload    bip1, bip2;
     349             :         struct bio_vec                  iv1, iv2;
     350             : #endif
     351             :         atomic_t                        cnt;
     352             :         int                             error;
     353             : };
     354             : extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
     355             : extern void bio_pair_release(struct bio_pair *dbio);
     356             : 
     357             : extern struct bio_set *bioset_create(unsigned int, unsigned int);
     358             : extern void bioset_free(struct bio_set *);
     359             : 
     360             : extern struct bio *bio_alloc(gfp_t, int);
     361             : extern struct bio *bio_kmalloc(gfp_t, int);
     362             : extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
     363             : extern void bio_put(struct bio *);
     364             : extern void bio_free(struct bio *, struct bio_set *);
     365             : 
     366             : extern void bio_endio(struct bio *, int);
     367             : struct request_queue;
     368             : extern int bio_phys_segments(struct request_queue *, struct bio *);
     369             : 
     370             : extern void __bio_clone(struct bio *, struct bio *);
     371             : extern struct bio *bio_clone(struct bio *, gfp_t);
     372             : 
     373             : extern void bio_init(struct bio *);
     374             : 
     375             : extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
     376             : extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
     377             :                            unsigned int, unsigned int);
     378             : extern int bio_get_nr_vecs(struct block_device *);
     379             : extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
     380             : extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
     381             :                                 unsigned long, unsigned int, int, gfp_t);
     382             : struct sg_iovec;
     383             : struct rq_map_data;
     384             : extern struct bio *bio_map_user_iov(struct request_queue *,
     385             :                                     struct block_device *,
     386             :                                     struct sg_iovec *, int, int, gfp_t);
     387             : extern void bio_unmap_user(struct bio *);
     388             : extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
     389             :                                 gfp_t);
     390             : extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
     391             :                                  gfp_t, int);
     392             : extern void bio_set_pages_dirty(struct bio *bio);
     393             : extern void bio_check_pages_dirty(struct bio *bio);
     394             : 
     395             : #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
     396             : # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
     397             : #endif
     398             : #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
     399             : extern void bio_flush_dcache_pages(struct bio *bi);
     400             : #else
     401             : static inline void bio_flush_dcache_pages(struct bio *bi)
     402             : {
     403             : }
     404             : #endif
     405             : 
     406             : extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
     407             :                                  unsigned long, unsigned int, int, gfp_t);
     408             : extern struct bio *bio_copy_user_iov(struct request_queue *,
     409             :                                      struct rq_map_data *, struct sg_iovec *,
     410             :                                      int, int, gfp_t);
     411             : extern int bio_uncopy_user(struct bio *);
     412             : void zero_fill_bio(struct bio *bio);
     413             : extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
     414             : extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
     415             : extern unsigned int bvec_nr_vecs(unsigned short idx);
     416             : 
     417             : /*
     418             :  * Allow queuer to specify a completion CPU for this bio
     419             :  */
     420             : static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
     421             : {
     422             :         bio->bi_comp_cpu = cpu;
     423             : }
     424             : 
     425             : /*
     426             :  * bio_set is used to allow other portions of the IO system to
     427             :  * allocate their own private memory pools for bio and iovec structures.
     428             :  * These memory pools in turn all allocate from the bio_slab
     429             :  * and the bvec_slabs[].
     430             :  */
     431             : #define BIO_POOL_SIZE 2
     432             : #define BIOVEC_NR_POOLS 6
     433             : #define BIOVEC_MAX_IDX  (BIOVEC_NR_POOLS - 1)
     434             : 
     435             : struct bio_set {
     436             :         struct kmem_cache *bio_slab;
     437             :         unsigned int front_pad;
     438             : 
     439             :         mempool_t *bio_pool;
     440             : #if defined(CONFIG_BLK_DEV_INTEGRITY)
     441             :         mempool_t *bio_integrity_pool;
     442             : #endif
     443             :         mempool_t *bvec_pool;
     444             : };
     445             : 
     446             : struct biovec_slab {
     447             :         int nr_vecs;
     448             :         char *name;
     449             :         struct kmem_cache *slab;
     450             : };
     451             : 
     452             : extern struct bio_set *fs_bio_set;
     453             : extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
     454             : 
     455             : /*
     456             :  * a small number of entries is fine, not going to be performance critical.
     457             :  * basically we just need to survive
     458             :  */
     459             : #define BIO_SPLIT_ENTRIES 2
     460             : 
     461             : #ifdef CONFIG_HIGHMEM
     462             : /*
     463             :  * remember never ever reenable interrupts between a bvec_kmap_irq and
     464             :  * bvec_kunmap_irq!
     465             :  */
     466             : static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
     467             : {
     468             :         unsigned long addr;
     469             : 
     470             :         /*
     471             :          * might not be a highmem page, but the preempt/irq count
     472             :          * balancing is a lot nicer this way
     473             :          */
     474             :         local_irq_save(*flags);
     475             :         addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
     476             : 
     477             :         BUG_ON(addr & ~PAGE_MASK);
     478             : 
     479             :         return (char *) addr + bvec->bv_offset;
     480             : }
     481             : 
     482             : static inline void bvec_kunmap_irq(char *buffer, 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 */

Generated by: LCOV version 1.10