include/linux/blk_types.h

   1 /*
   2  * Block data types and constants.  Directly include this file only to
   3  * break include dependency loop.
   4  */
   5 #ifndef __LINUX_BLK_TYPES_H
   6 #define __LINUX_BLK_TYPES_H
   7
   8 #ifdef CONFIG_BLOCK
   9
  10 #include <linux/types.h>
  11
  12 struct bio_set;
  13 struct bio;
  14 struct bio_integrity_payload;
  15 struct page;
  16 struct block_device;
  17 typedef void (bio_end_io_t) (struct bio *, int);
  18 typedef void (bio_destructor_t) (struct bio *);
  19
  20 /*
  21  * was unsigned short, but we might as well be ready for > 64kB I/O pages
  22  */
  23 struct bio_vec {
  24         struct page     *bv_page;
  25         unsigned int    bv_len;
  26         unsigned int    bv_offset;
  27 };
  28
  29 /*
  30  * main unit of I/O for the block layer and lower layers (ie drivers and
  31  * stacking drivers)
  32  */
  33 struct bio {
  34         sector_t                bi_sector;      /* device address in 512 byte
  35                                                    sectors */
  36         struct bio              *bi_next;       /* request queue link */
  37         struct block_device     *bi_bdev;
  38         unsigned long           bi_flags;       /* status, command, etc */
  39         unsigned long           bi_rw;          /* bottom bits READ/WRITE,
  40                                                  * top bits priority
  41                                                  */
  42
  43         unsigned short          bi_vcnt;        /* how many bio_vec's */
  44         unsigned short          bi_idx;         /* current index into bvl_vec */
  45
  46         /* Number of segments in this BIO after
  47          * physical address coalescing is performed.
  48          */
  49         unsigned int            bi_phys_segments;
  50
  51         unsigned int            bi_size;        /* residual I/O count */
  52
  53         /*
  54          * To keep track of the max segment size, we account for the
  55          * sizes of the first and last mergeable segments in this bio.
  56          */
  57         unsigned int            bi_seg_front_size;
  58         unsigned int            bi_seg_back_size;
  59
  60         unsigned int            bi_max_vecs;    /* max bvl_vecs we can hold */
  61
  62         unsigned int            bi_comp_cpu;    /* completion CPU */
  63
  64         atomic_t                bi_cnt;         /* pin count */
  65
  66         struct bio_vec          *bi_io_vec;     /* the actual vec list */
  67
  68         bio_end_io_t            *bi_end_io;
  69
  70         void                    *bi_private;
  71 #if defined(CONFIG_BLK_DEV_INTEGRITY)
  72         struct bio_integrity_payload *bi_integrity;  /* data integrity */
  73 #endif
  74
  75         bio_destructor_t        *bi_destructor; /* destructor */
  76
  77         /*
  78          * We can inline a number of vecs at the end of the bio, to avoid
  79          * double allocations for a small number of bio_vecs. This member
  80          * MUST obviously be kept at the very end of the bio.
  81          */
  82         struct bio_vec          bi_inline_vecs[0];
  83 };
  84
  85 /*
  86  * bio flags
  87  */
  88 #define BIO_UPTODATE    0       /* ok after I/O completion */
  89 #define BIO_RW_BLOCK    1       /* RW_AHEAD set, and read/write would block */
  90 #define BIO_EOF         2       /* out-out-bounds error */
  91 #define BIO_SEG_VALID   3       /* bi_phys_segments valid */
  92 #define BIO_CLONED      4       /* doesn't own data */
  93 #define BIO_BOUNCED     5       /* bio is a bounce bio */
  94 #define BIO_USER_MAPPED 6       /* contains user pages */
  95 #define BIO_EOPNOTSUPP  7       /* not supported */
  96 #define BIO_CPU_AFFINE  8       /* complete bio on same CPU as submitted */
  97 #define BIO_NULL_MAPPED 9       /* contains invalid user pages */
  98 #define BIO_FS_INTEGRITY 10     /* fs owns integrity data, not block layer */
  99 #define BIO_QUIET       11      /* Make BIO Quiet */
 100 #define BIO_MAPPED_INTEGRITY 12/* integrity metadata has been remapped */
 101 #define bio_flagged(bio, flag)  ((bio)->bi_flags & (1 << (flag)))
 102
 103 /*
 104  * top 4 bits of bio flags indicate the pool this bio came from
 105  */
 106 #define BIO_POOL_BITS           (4)
 107 #define BIO_POOL_NONE           ((1UL << BIO_POOL_BITS) - 1)
 108 #define BIO_POOL_OFFSET         (BITS_PER_LONG - BIO_POOL_BITS)
 109 #define BIO_POOL_MASK           (1UL << BIO_POOL_OFFSET)
 110 #define BIO_POOL_IDX(bio)       ((bio)->bi_flags >> BIO_POOL_OFFSET)
 111
 112 #endif /* CONFIG_BLOCK */
 113
 114 /*
 115  * Request flags.  For use in the cmd_flags field of struct request, and in
 116  * bi_rw of struct bio.  Note that some flags are only valid in either one.
 117  */
 118 enum rq_flag_bits {
 119         /* common flags */
 120         __REQ_WRITE,            /* not set, read. set, write */
 121         __REQ_FAILFAST_DEV,     /* no driver retries of device errors */
 122         __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
 123         __REQ_FAILFAST_DRIVER,  /* no driver retries of driver errors */
 124
 125         __REQ_SYNC,             /* request is sync (sync write or read) */
 126         __REQ_META,             /* metadata io request */
 127         __REQ_DISCARD,          /* request to discard sectors */
 128         __REQ_NOIDLE,           /* don't anticipate more IO after this one */
 129
 130         /* bio only flags */
 131         __REQ_RAHEAD,           /* read ahead, can fail anytime */
 132         __REQ_THROTTLED,        /* This bio has already been subjected to
 133                                  * throttling rules. Don't do it again. */
 134
 135         /* request only flags */
 136         __REQ_SORTED,           /* elevator knows about this request */
 137         __REQ_SOFTBARRIER,      /* may not be passed by ioscheduler */
 138         __REQ_FUA,              /* forced unit access */
 139         __REQ_NOMERGE,          /* don't touch this for merging */
 140         __REQ_STARTED,          /* drive already may have started this one */
 141         __REQ_DONTPREP,         /* don't call prep for this one */
 142         __REQ_QUEUED,           /* uses queueing */
 143         __REQ_ELVPRIV,          /* elevator private data attached */
 144         __REQ_FAILED,           /* set if the request failed */
 145         __REQ_QUIET,            /* don't worry about errors */
 146         __REQ_PREEMPT,          /* set for "ide_preempt" requests */
 147         __REQ_ALLOCED,          /* request came from our alloc pool */
 148         __REQ_COPY_USER,        /* contains copies of user pages */
 149         __REQ_FLUSH,            /* request for cache flush */
 150         __REQ_FLUSH_SEQ,        /* request for flush sequence */
 151         __REQ_IO_STAT,          /* account I/O stat */
 152         __REQ_MIXED_MERGE,      /* merge of different types, fail separately */
 153         __REQ_SECURE,           /* secure discard (used with __REQ_DISCARD) */
 154         __REQ_ON_PLUG,          /* on plug list */
 155         __REQ_NR_BITS,          /* stops here */
 156 };
 157
 158 #define REQ_WRITE               (1 << __REQ_WRITE)
 159 #define REQ_FAILFAST_DEV        (1 << __REQ_FAILFAST_DEV)
 160 #define REQ_FAILFAST_TRANSPORT  (1 << __REQ_FAILFAST_TRANSPORT)
 161 #define REQ_FAILFAST_DRIVER     (1 << __REQ_FAILFAST_DRIVER)
 162 #define REQ_SYNC                (1 << __REQ_SYNC)
 163 #define REQ_META                (1 << __REQ_META)
 164 #define REQ_DISCARD             (1 << __REQ_DISCARD)
 165 #define REQ_NOIDLE              (1 << __REQ_NOIDLE)
 166
 167 #define REQ_FAILFAST_MASK \
 168         (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 169 #define REQ_COMMON_MASK \
 170         (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_DISCARD | \
 171          REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
 172 #define REQ_CLONE_MASK          REQ_COMMON_MASK
 173
 174 #define REQ_RAHEAD              (1 << __REQ_RAHEAD)
 175 #define REQ_THROTTLED           (1 << __REQ_THROTTLED)
 176
 177 #define REQ_SORTED              (1 << __REQ_SORTED)
 178 #define REQ_SOFTBARRIER         (1 << __REQ_SOFTBARRIER)
 179 #define REQ_FUA                 (1 << __REQ_FUA)
 180 #define REQ_NOMERGE             (1 << __REQ_NOMERGE)
 181 #define REQ_STARTED             (1 << __REQ_STARTED)
 182 #define REQ_DONTPREP            (1 << __REQ_DONTPREP)
 183 #define REQ_QUEUED              (1 << __REQ_QUEUED)
 184 #define REQ_ELVPRIV             (1 << __REQ_ELVPRIV)
 185 #define REQ_FAILED              (1 << __REQ_FAILED)
 186 #define REQ_QUIET               (1 << __REQ_QUIET)
 187 #define REQ_PREEMPT             (1 << __REQ_PREEMPT)
 188 #define REQ_ALLOCED             (1 << __REQ_ALLOCED)
 189 #define REQ_COPY_USER           (1 << __REQ_COPY_USER)
 190 #define REQ_FLUSH               (1 << __REQ_FLUSH)
 191 #define REQ_FLUSH_SEQ           (1 << __REQ_FLUSH_SEQ)
 192 #define REQ_IO_STAT             (1 << __REQ_IO_STAT)
 193 #define REQ_MIXED_MERGE         (1 << __REQ_MIXED_MERGE)
 194 #define REQ_SECURE              (1 << __REQ_SECURE)
 195 #define REQ_ON_PLUG             (1 << __REQ_ON_PLUG)
 196
 197 #endif /* __LINUX_BLK_TYPES_H */