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  * Alpha cannot write a byte atomically, so we need to use 32-bit value.
  24  */
  25 #if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
  26 typedef u32 __bitwise blk_status_t;
  27 #else
  28 typedef u8 __bitwise blk_status_t;
  29 #endif
  30 #define BLK_STS_OK 0
  31 #define BLK_STS_NOTSUPP         ((__force blk_status_t)1)
  32 #define BLK_STS_TIMEOUT         ((__force blk_status_t)2)
  33 #define BLK_STS_NOSPC           ((__force blk_status_t)3)
  34 #define BLK_STS_TRANSPORT       ((__force blk_status_t)4)
  35 #define BLK_STS_TARGET          ((__force blk_status_t)5)
  36 #define BLK_STS_NEXUS           ((__force blk_status_t)6)
  37 #define BLK_STS_MEDIUM          ((__force blk_status_t)7)
  38 #define BLK_STS_PROTECTION      ((__force blk_status_t)8)
  39 #define BLK_STS_RESOURCE        ((__force blk_status_t)9)
  40 #define BLK_STS_IOERR           ((__force blk_status_t)10)
  41
  42 /* hack for device mapper, don't use elsewhere: */
  43 #define BLK_STS_DM_REQUEUE    ((__force blk_status_t)11)
  44
  45 #define BLK_STS_AGAIN           ((__force blk_status_t)12)
  46
  47 struct blk_issue_stat {
  48         u64 stat;
  49 };
  50
  51 /*
  52  * main unit of I/O for the block layer and lower layers (ie drivers and
  53  * stacking drivers)
  54  */
  55 struct bio {
  56         struct bio              *bi_next;       /* request queue link */
  57         struct gendisk          *bi_disk;
  58         unsigned int            bi_opf;         /* bottom bits req flags,
  59                                                  * top bits REQ_OP. Use
  60                                                  * accessors.
  61                                                  */
  62         unsigned short          bi_flags;       /* status, etc and bvec pool number */
  63         unsigned short          bi_ioprio;
  64         unsigned short          bi_write_hint;
  65         blk_status_t            bi_status;
  66         u8                      bi_partno;
  67
  68         /* Number of segments in this BIO after
  69          * physical address coalescing is performed.
  70          */
  71         unsigned int            bi_phys_segments;
  72
  73         /*
  74          * To keep track of the max segment size, we account for the
  75          * sizes of the first and last mergeable segments in this bio.
  76          */
  77         unsigned int            bi_seg_front_size;
  78         unsigned int            bi_seg_back_size;
  79
  80         struct bvec_iter        bi_iter;
  81
  82         atomic_t                __bi_remaining;
  83         bio_end_io_t            *bi_end_io;
  84
  85         void                    *bi_private;
  86 #ifdef CONFIG_BLK_CGROUP
  87         /*
  88          * Optional ioc and css associated with this bio.  Put on bio
  89          * release.  Read comment on top of bio_associate_current().
  90          */
  91         struct io_context       *bi_ioc;
  92         struct cgroup_subsys_state *bi_css;
  93 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
  94         void                    *bi_cg_private;
  95         struct blk_issue_stat   bi_issue_stat;
  96 #endif
  97 #endif
  98         union {
  99 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 100                 struct bio_integrity_payload *bi_integrity; /* data integrity */
 101 #endif
 102         };
 103
 104         unsigned short          bi_vcnt;        /* how many bio_vec's */
 105
 106         /*
 107          * Everything starting with bi_max_vecs will be preserved by bio_reset()
 108          */
 109
 110         unsigned short          bi_max_vecs;    /* max bvl_vecs we can hold */
 111
 112         atomic_t                __bi_cnt;       /* pin count */
 113
 114         struct bio_vec          *bi_io_vec;     /* the actual vec list */
 115
 116         struct bio_set          *bi_pool;
 117
 118         /*
 119          * We can inline a number of vecs at the end of the bio, to avoid
 120          * double allocations for a small number of bio_vecs. This member
 121          * MUST obviously be kept at the very end of the bio.
 122          */
 123         struct bio_vec          bi_inline_vecs[0];
 124 };
 125
 126 #define BIO_RESET_BYTES         offsetof(struct bio, bi_max_vecs)
 127
 128 /*
 129  * bio flags
 130  */
 131 #define BIO_SEG_VALID   1       /* bi_phys_segments valid */
 132 #define BIO_CLONED      2       /* doesn't own data */
 133 #define BIO_BOUNCED     3       /* bio is a bounce bio */
 134 #define BIO_USER_MAPPED 4       /* contains user pages */
 135 #define BIO_NULL_MAPPED 5       /* contains invalid user pages */
 136 #define BIO_QUIET       6       /* Make BIO Quiet */
 137 #define BIO_CHAIN       7       /* chained bio, ->bi_remaining in effect */
 138 #define BIO_REFFED      8       /* bio has elevated ->bi_cnt */
 139 #define BIO_THROTTLED   9       /* This bio has already been subjected to
 140                                  * throttling rules. Don't do it again. */
 141 #define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
 142                                  * of this bio. */
 143 /* See BVEC_POOL_OFFSET below before adding new flags */
 144
 145 /*
 146  * We support 6 different bvec pools, the last one is magic in that it
 147  * is backed by a mempool.
 148  */
 149 #define BVEC_POOL_NR            6
 150 #define BVEC_POOL_MAX           (BVEC_POOL_NR - 1)
 151
 152 /*
 153  * Top 3 bits of bio flags indicate the pool the bvecs came from.  We add
 154  * 1 to the actual index so that 0 indicates that there are no bvecs to be
 155  * freed.
 156  */
 157 #define BVEC_POOL_BITS          (3)
 158 #define BVEC_POOL_OFFSET        (16 - BVEC_POOL_BITS)
 159 #define BVEC_POOL_IDX(bio)      ((bio)->bi_flags >> BVEC_POOL_OFFSET)
 160 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
 161 # error "BVEC_POOL_BITS is too small"
 162 #endif
 163
 164 /*
 165  * Flags starting here get preserved by bio_reset() - this includes
 166  * only BVEC_POOL_IDX()
 167  */
 168 #define BIO_RESET_BITS  BVEC_POOL_OFFSET
 169
 170 typedef __u32 __bitwise blk_mq_req_flags_t;
 171
 172 /*
 173  * Operations and flags common to the bio and request structures.
 174  * We use 8 bits for encoding the operation, and the remaining 24 for flags.
 175  *
 176  * The least significant bit of the operation number indicates the data
 177  * transfer direction:
 178  *
 179  *   - if the least significant bit is set transfers are TO the device
 180  *   - if the least significant bit is not set transfers are FROM the device
 181  *
 182  * If a operation does not transfer data the least significant bit has no
 183  * meaning.
 184  */
 185 #define REQ_OP_BITS     8
 186 #define REQ_OP_MASK     ((1 << REQ_OP_BITS) - 1)
 187 #define REQ_FLAG_BITS   24
 188
 189 enum req_opf {
 190         /* read sectors from the device */
 191         REQ_OP_READ             = 0,
 192         /* write sectors to the device */
 193         REQ_OP_WRITE            = 1,
 194         /* flush the volatile write cache */
 195         REQ_OP_FLUSH            = 2,
 196         /* discard sectors */
 197         REQ_OP_DISCARD          = 3,
 198         /* get zone information */
 199         REQ_OP_ZONE_REPORT      = 4,
 200         /* securely erase sectors */
 201         REQ_OP_SECURE_ERASE     = 5,
 202         /* seset a zone write pointer */
 203         REQ_OP_ZONE_RESET       = 6,
 204         /* write the same sector many times */
 205         REQ_OP_WRITE_SAME       = 7,
 206         /* write the zero filled sector many times */
 207         REQ_OP_WRITE_ZEROES     = 9,
 208
 209         /* SCSI passthrough using struct scsi_request */
 210         REQ_OP_SCSI_IN          = 32,
 211         REQ_OP_SCSI_OUT         = 33,
 212         /* Driver private requests */
 213         REQ_OP_DRV_IN           = 34,
 214         REQ_OP_DRV_OUT          = 35,
 215
 216         REQ_OP_LAST,
 217 };
 218
 219 enum req_flag_bits {
 220         __REQ_FAILFAST_DEV =    /* no driver retries of device errors */
 221                 REQ_OP_BITS,
 222         __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
 223         __REQ_FAILFAST_DRIVER,  /* no driver retries of driver errors */
 224         __REQ_SYNC,             /* request is sync (sync write or read) */
 225         __REQ_META,             /* metadata io request */
 226         __REQ_PRIO,             /* boost priority in cfq */
 227         __REQ_NOMERGE,          /* don't touch this for merging */
 228         __REQ_IDLE,             /* anticipate more IO after this one */
 229         __REQ_INTEGRITY,        /* I/O includes block integrity payload */
 230         __REQ_FUA,              /* forced unit access */
 231         __REQ_PREFLUSH,         /* request for cache flush */
 232         __REQ_RAHEAD,           /* read ahead, can fail anytime */
 233         __REQ_BACKGROUND,       /* background IO */
 234         __REQ_NOWAIT,           /* Don't wait if request will block */
 235
 236         /* command specific flags for REQ_OP_WRITE_ZEROES: */
 237         __REQ_NOUNMAP,          /* do not free blocks when zeroing */
 238
 239         /* for driver use */
 240         __REQ_DRV,
 241
 242         __REQ_NR_BITS,          /* stops here */
 243 };
 244
 245 #define REQ_FAILFAST_DEV        (1ULL << __REQ_FAILFAST_DEV)
 246 #define REQ_FAILFAST_TRANSPORT  (1ULL << __REQ_FAILFAST_TRANSPORT)
 247 #define REQ_FAILFAST_DRIVER     (1ULL << __REQ_FAILFAST_DRIVER)
 248 #define REQ_SYNC                (1ULL << __REQ_SYNC)
 249 #define REQ_META                (1ULL << __REQ_META)
 250 #define REQ_PRIO                (1ULL << __REQ_PRIO)
 251 #define REQ_NOMERGE             (1ULL << __REQ_NOMERGE)
 252 #define REQ_IDLE                (1ULL << __REQ_IDLE)
 253 #define REQ_INTEGRITY           (1ULL << __REQ_INTEGRITY)
 254 #define REQ_FUA                 (1ULL << __REQ_FUA)
 255 #define REQ_PREFLUSH            (1ULL << __REQ_PREFLUSH)
 256 #define REQ_RAHEAD              (1ULL << __REQ_RAHEAD)
 257 #define REQ_BACKGROUND          (1ULL << __REQ_BACKGROUND)
 258 #define REQ_NOWAIT              (1ULL << __REQ_NOWAIT)
 259
 260 #define REQ_NOUNMAP             (1ULL << __REQ_NOUNMAP)
 261
 262 #define REQ_DRV                 (1ULL << __REQ_DRV)
 263
 264 #define REQ_FAILFAST_MASK \
 265         (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 266
 267 #define REQ_NOMERGE_FLAGS \
 268         (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
 269
 270 #define bio_op(bio) \
 271         ((bio)->bi_opf & REQ_OP_MASK)
 272 #define req_op(req) \
 273         ((req)->cmd_flags & REQ_OP_MASK)
 274
 275 /* obsolete, don't use in new code */
 276 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
 277                 unsigned op_flags)
 278 {
 279         bio->bi_opf = op | op_flags;
 280 }
 281
 282 static inline bool op_is_write(unsigned int op)
 283 {
 284         return (op & 1);
 285 }
 286
 287 /*
 288  * Check if the bio or request is one that needs special treatment in the
 289  * flush state machine.
 290  */
 291 static inline bool op_is_flush(unsigned int op)
 292 {
 293         return op & (REQ_FUA | REQ_PREFLUSH);
 294 }
 295
 296 /*
 297  * Reads are always treated as synchronous, as are requests with the FUA or
 298  * PREFLUSH flag.  Other operations may be marked as synchronous using the
 299  * REQ_SYNC flag.
 300  */
 301 static inline bool op_is_sync(unsigned int op)
 302 {
 303         return (op & REQ_OP_MASK) == REQ_OP_READ ||
 304                 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
 305 }
 306
 307 typedef unsigned int blk_qc_t;
 308 #define BLK_QC_T_NONE           -1U
 309 #define BLK_QC_T_SHIFT          16
 310 #define BLK_QC_T_INTERNAL       (1U << 31)
 311
 312 static inline bool blk_qc_t_valid(blk_qc_t cookie)
 313 {
 314         return cookie != BLK_QC_T_NONE;
 315 }
 316
 317 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
 318                                        bool internal)
 319 {
 320         blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
 321
 322         if (internal)
 323                 ret |= BLK_QC_T_INTERNAL;
 324
 325         return ret;
 326 }
 327
 328 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
 329 {
 330         return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
 331 }
 332
 333 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
 334 {
 335         return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
 336 }
 337
 338 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
 339 {
 340         return (cookie & BLK_QC_T_INTERNAL) != 0;
 341 }
 342
 343 struct blk_rq_stat {
 344         u64 mean;
 345         u64 min;
 346         u64 max;
 347         u32 nr_samples;
 348         u64 batch;
 349 };
 350
 351 #endif /* __LINUX_BLK_TYPES_H */