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