include/linux/blk_types.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Block data types and constants.  Directly include this file only to
   4  * break include dependency loop.
   5  */
   6 #ifndef __LINUX_BLK_TYPES_H
   7 #define __LINUX_BLK_TYPES_H
   8
   9 #include <linux/types.h>
  10 #include <linux/bvec.h>
  11
  12 struct bio_set;
  13 struct bio;
  14 struct bio_integrity_payload;
  15 struct page;
  16 struct block_device;
  17 struct io_context;
  18 struct cgroup_subsys_state;
  19 typedef void (bio_end_io_t) (struct bio *);
  20
  21 /*
  22  * Block error status values.  See block/blk-core:blk_errors for the details.
  23  */
  24 typedef u8 __bitwise blk_status_t;
  25 #define BLK_STS_OK 0
  26 #define BLK_STS_NOTSUPP         ((__force blk_status_t)1)
  27 #define BLK_STS_TIMEOUT         ((__force blk_status_t)2)
  28 #define BLK_STS_NOSPC           ((__force blk_status_t)3)
  29 #define BLK_STS_TRANSPORT       ((__force blk_status_t)4)
  30 #define BLK_STS_TARGET          ((__force blk_status_t)5)
  31 #define BLK_STS_NEXUS           ((__force blk_status_t)6)
  32 #define BLK_STS_MEDIUM          ((__force blk_status_t)7)
  33 #define BLK_STS_PROTECTION      ((__force blk_status_t)8)
  34 #define BLK_STS_RESOURCE        ((__force blk_status_t)9)
  35 #define BLK_STS_IOERR           ((__force blk_status_t)10)
  36
  37 /* hack for device mapper, don't use elsewhere: */
  38 #define BLK_STS_DM_REQUEUE    ((__force blk_status_t)11)
  39
  40 #define BLK_STS_AGAIN           ((__force blk_status_t)12)
  41
  42 struct blk_issue_stat {
  43         u64 stat;
  44 };
  45
  46 /*
  47  * main unit of I/O for the block layer and lower layers (ie drivers and
  48  * stacking drivers)
  49  */
  50 struct bio {
  51         struct bio              *bi_next;       /* request queue link */
  52         struct gendisk          *bi_disk;
  53         u8                      bi_partno;
  54         blk_status_t            bi_status;
  55         unsigned int            bi_opf;         /* bottom bits req flags,
  56                                                  * top bits REQ_OP. Use
  57                                                  * accessors.
  58                                                  */
  59         unsigned short          bi_flags;       /* status, etc and bvec pool number */
  60         unsigned short          bi_ioprio;
  61         unsigned short          bi_write_hint;
  62
  63         struct bvec_iter        bi_iter;
  64
  65         /* Number of segments in this BIO after
  66          * physical address coalescing is performed.
  67          */
  68         unsigned int            bi_phys_segments;
  69
  70         /*
  71          * To keep track of the max segment size, we account for the
  72          * sizes of the first and last mergeable segments in this bio.
  73          */
  74         unsigned int            bi_seg_front_size;
  75         unsigned int            bi_seg_back_size;
  76
  77         atomic_t                __bi_remaining;
  78
  79         bio_end_io_t            *bi_end_io;
  80
  81         void                    *bi_private;
  82 #ifdef CONFIG_BLK_CGROUP
  83         /*
  84          * Optional ioc and css associated with this bio.  Put on bio
  85          * release.  Read comment on top of bio_associate_current().
  86          */
  87         struct io_context       *bi_ioc;
  88         struct cgroup_subsys_state *bi_css;
  89 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
  90         void                    *bi_cg_private;
  91         struct blk_issue_stat   bi_issue_stat;
  92 #endif
  93 #endif
  94         union {
  95 #if defined(CONFIG_BLK_DEV_INTEGRITY)
  96                 struct bio_integrity_payload *bi_integrity; /* data integrity */
  97 #endif
  98         };
  99
 100         unsigned short          bi_vcnt;        /* how many bio_vec's */
 101
 102         /*
 103          * Everything starting with bi_max_vecs will be preserved by bio_reset()
 104          */
 105
 106         unsigned short          bi_max_vecs;    /* max bvl_vecs we can hold */
 107
 108         atomic_t                __bi_cnt;       /* pin count */
 109
 110         struct bio_vec          *bi_io_vec;     /* the actual vec list */
 111
 112         struct bio_set          *bi_pool;
 113
 114         /*
 115          * We can inline a number of vecs at the end of the bio, to avoid
 116          * double allocations for a small number of bio_vecs. This member
 117          * MUST obviously be kept at the very end of the bio.
 118          */
 119         struct bio_vec          bi_inline_vecs[0];
 120 };
 121
 122 #define BIO_RESET_BYTES         offsetof(struct bio, bi_max_vecs)
 123
 124 /*
 125  * bio flags
 126  */
 127 #define BIO_SEG_VALID   1       /* bi_phys_segments valid */
 128 #define BIO_CLONED      2       /* doesn't own data */
 129 #define BIO_BOUNCED     3       /* bio is a bounce bio */
 130 #define BIO_USER_MAPPED 4       /* contains user pages */
 131 #define BIO_NULL_MAPPED 5       /* contains invalid user pages */
 132 #define BIO_QUIET       6       /* Make BIO Quiet */
 133 #define BIO_CHAIN       7       /* chained bio, ->bi_remaining in effect */
 134 #define BIO_REFFED      8       /* bio has elevated ->bi_cnt */
 135 #define BIO_THROTTLED   9       /* This bio has already been subjected to
 136                                  * throttling rules. Don't do it again. */
 137 #define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
 138                                  * of this bio. */
 139 /* See BVEC_POOL_OFFSET below before adding new flags */
 140
 141 /*
 142  * We support 6 different bvec pools, the last one is magic in that it
 143  * is backed by a mempool.
 144  */
 145 #define BVEC_POOL_NR            6
 146 #define BVEC_POOL_MAX           (BVEC_POOL_NR - 1)
 147
 148 /*
 149  * Top 3 bits of bio flags indicate the pool the bvecs came from.  We add
 150  * 1 to the actual index so that 0 indicates that there are no bvecs to be
 151  * freed.
 152  */
 153 #define BVEC_POOL_BITS          (3)
 154 #define BVEC_POOL_OFFSET        (16 - BVEC_POOL_BITS)
 155 #define BVEC_POOL_IDX(bio)      ((bio)->bi_flags >> BVEC_POOL_OFFSET)
 156 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
 157 # error "BVEC_POOL_BITS is too small"
 158 #endif
 159
 160 /*
 161  * Flags starting here get preserved by bio_reset() - this includes
 162  * only BVEC_POOL_IDX()
 163  */
 164 #define BIO_RESET_BITS  BVEC_POOL_OFFSET
 165
 166 /*
 167  * Operations and flags common to the bio and request structures.
 168  * We use 8 bits for encoding the operation, and the remaining 24 for flags.
 169  *
 170  * The least significant bit of the operation number indicates the data
 171  * transfer direction:
 172  *
 173  *   - if the least significant bit is set transfers are TO the device
 174  *   - if the least significant bit is not set transfers are FROM the device
 175  *
 176  * If a operation does not transfer data the least significant bit has no
 177  * meaning.
 178  */
 179 #define REQ_OP_BITS     8
 180 #define REQ_OP_MASK     ((1 << REQ_OP_BITS) - 1)
 181 #define REQ_FLAG_BITS   24
 182
 183 enum req_opf {
 184         /* read sectors from the device */
 185         REQ_OP_READ             = 0,
 186         /* write sectors to the device */
 187         REQ_OP_WRITE            = 1,
 188         /* flush the volatile write cache */
 189         REQ_OP_FLUSH            = 2,
 190         /* discard sectors */
 191         REQ_OP_DISCARD          = 3,
 192         /* get zone information */
 193         REQ_OP_ZONE_REPORT      = 4,
 194         /* securely erase sectors */
 195         REQ_OP_SECURE_ERASE     = 5,
 196         /* seset a zone write pointer */
 197         REQ_OP_ZONE_RESET       = 6,
 198         /* write the same sector many times */
 199         REQ_OP_WRITE_SAME       = 7,
 200         /* write the zero filled sector many times */
 201         REQ_OP_WRITE_ZEROES     = 9,
 202
 203         /* SCSI passthrough using struct scsi_request */
 204         REQ_OP_SCSI_IN          = 32,
 205         REQ_OP_SCSI_OUT         = 33,
 206         /* Driver private requests */
 207         REQ_OP_DRV_IN           = 34,
 208         REQ_OP_DRV_OUT          = 35,
 209
 210         REQ_OP_LAST,
 211 };
 212
 213 enum req_flag_bits {
 214         __REQ_FAILFAST_DEV =    /* no driver retries of device errors */
 215                 REQ_OP_BITS,
 216         __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
 217         __REQ_FAILFAST_DRIVER,  /* no driver retries of driver errors */
 218         __REQ_SYNC,             /* request is sync (sync write or read) */
 219         __REQ_META,             /* metadata io request */
 220         __REQ_PRIO,             /* boost priority in cfq */
 221         __REQ_NOMERGE,          /* don't touch this for merging */
 222         __REQ_IDLE,             /* anticipate more IO after this one */
 223         __REQ_INTEGRITY,        /* I/O includes block integrity payload */
 224         __REQ_FUA,              /* forced unit access */
 225         __REQ_PREFLUSH,         /* request for cache flush */
 226         __REQ_RAHEAD,           /* read ahead, can fail anytime */
 227         __REQ_BACKGROUND,       /* background IO */
 228
 229         /* command specific flags for REQ_OP_WRITE_ZEROES: */
 230         __REQ_NOUNMAP,          /* do not free blocks when zeroing */
 231
 232         __REQ_NOWAIT,           /* Don't wait if request will block */
 233         __REQ_NR_BITS,          /* stops here */
 234 };
 235
 236 #define REQ_FAILFAST_DEV        (1ULL << __REQ_FAILFAST_DEV)
 237 #define REQ_FAILFAST_TRANSPORT  (1ULL << __REQ_FAILFAST_TRANSPORT)
 238 #define REQ_FAILFAST_DRIVER     (1ULL << __REQ_FAILFAST_DRIVER)
 239 #define REQ_SYNC                (1ULL << __REQ_SYNC)
 240 #define REQ_META                (1ULL << __REQ_META)
 241 #define REQ_PRIO                (1ULL << __REQ_PRIO)
 242 #define REQ_NOMERGE             (1ULL << __REQ_NOMERGE)
 243 #define REQ_IDLE                (1ULL << __REQ_IDLE)
 244 #define REQ_INTEGRITY           (1ULL << __REQ_INTEGRITY)
 245 #define REQ_FUA                 (1ULL << __REQ_FUA)
 246 #define REQ_PREFLUSH            (1ULL << __REQ_PREFLUSH)
 247 #define REQ_RAHEAD              (1ULL << __REQ_RAHEAD)
 248 #define REQ_BACKGROUND          (1ULL << __REQ_BACKGROUND)
 249
 250 #define REQ_NOUNMAP             (1ULL << __REQ_NOUNMAP)
 251 #define REQ_NOWAIT              (1ULL << __REQ_NOWAIT)
 252
 253 #define REQ_FAILFAST_MASK \
 254         (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 255
 256 #define REQ_NOMERGE_FLAGS \
 257         (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
 258
 259 #define bio_op(bio) \
 260         ((bio)->bi_opf & REQ_OP_MASK)
 261 #define req_op(req) \
 262         ((req)->cmd_flags & REQ_OP_MASK)
 263
 264 /* obsolete, don't use in new code */
 265 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
 266                 unsigned op_flags)
 267 {
 268         bio->bi_opf = op | op_flags;
 269 }
 270
 271 static inline bool op_is_write(unsigned int op)
 272 {
 273         return (op & 1);
 274 }
 275
 276 /*
 277  * Check if the bio or request is one that needs special treatment in the
 278  * flush state machine.
 279  */
 280 static inline bool op_is_flush(unsigned int op)
 281 {
 282         return op & (REQ_FUA | REQ_PREFLUSH);
 283 }
 284
 285 /*
 286  * Reads are always treated as synchronous, as are requests with the FUA or
 287  * PREFLUSH flag.  Other operations may be marked as synchronous using the
 288  * REQ_SYNC flag.
 289  */
 290 static inline bool op_is_sync(unsigned int op)
 291 {
 292         return (op & REQ_OP_MASK) == REQ_OP_READ ||
 293                 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
 294 }
 295
 296 typedef unsigned int blk_qc_t;
 297 #define BLK_QC_T_NONE           -1U
 298 #define BLK_QC_T_SHIFT          16
 299 #define BLK_QC_T_INTERNAL       (1U << 31)
 300
 301 static inline bool blk_qc_t_valid(blk_qc_t cookie)
 302 {
 303         return cookie != BLK_QC_T_NONE;
 304 }
 305
 306 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
 307                                        bool internal)
 308 {
 309         blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
 310
 311         if (internal)
 312                 ret |= BLK_QC_T_INTERNAL;
 313
 314         return ret;
 315 }
 316
 317 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
 318 {
 319         return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
 320 }
 321
 322 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
 323 {
 324         return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
 325 }
 326
 327 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
 328 {
 329         return (cookie & BLK_QC_T_INTERNAL) != 0;
 330 }
 331
 332 struct blk_rq_stat {
 333         s64 mean;
 334         u64 min;
 335         u64 max;
 336         s32 nr_samples;
 337         s32 nr_batch;
 338         u64 batch;
 339 };
 340
 341 #endif /* __LINUX_BLK_TYPES_H */