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 #include <linux/device.h>
  12 #include <linux/ktime.h>
  13
  14 struct bio_set;
  15 struct bio;
  16 struct bio_integrity_payload;
  17 struct page;
  18 struct io_context;
  19 struct cgroup_subsys_state;
  20 typedef void (bio_end_io_t) (struct bio *);
  21 struct bio_crypt_ctx;
  22
  23 struct block_device {
  24         sector_t                bd_start_sect;
  25         struct disk_stats __percpu *bd_stats;
  26         unsigned long           bd_stamp;
  27         bool                    bd_read_only;   /* read-only policy */
  28         dev_t                   bd_dev;
  29         int                     bd_openers;
  30         struct inode *          bd_inode;       /* will die */
  31         struct super_block *    bd_super;
  32         struct mutex            bd_mutex;       /* open/close mutex */
  33         void *                  bd_claiming;
  34         struct device           bd_device;
  35         void *                  bd_holder;
  36         int                     bd_holders;
  37         bool                    bd_write_holder;
  38 #ifdef CONFIG_SYSFS
  39         struct list_head        bd_holder_disks;
  40 #endif
  41         struct kobject          *bd_holder_dir;
  42         u8                      bd_partno;
  43         /* number of times partitions within this device have been opened. */
  44         unsigned                bd_part_count;
  45
  46         spinlock_t              bd_size_lock; /* for bd_inode->i_size updates */
  47         struct gendisk *        bd_disk;
  48         struct backing_dev_info *bd_bdi;
  49
  50         /* The counter of freeze processes */
  51         int                     bd_fsfreeze_count;
  52         /* Mutex for freeze */
  53         struct mutex            bd_fsfreeze_mutex;
  54         struct super_block      *bd_fsfreeze_sb;
  55
  56         struct partition_meta_info *bd_meta_info;
  57 #ifdef CONFIG_FAIL_MAKE_REQUEST
  58         bool                    bd_make_it_fail;
  59 #endif
  60 } __randomize_layout;
  61
  62 #define bdev_whole(_bdev) \
  63         ((_bdev)->bd_disk->part0)
  64
  65 #define dev_to_bdev(device) \
  66         container_of((device), struct block_device, bd_device)
  67
  68 #define bdev_kobj(_bdev) \
  69         (&((_bdev)->bd_device.kobj))
  70
  71 /*
  72  * Block error status values.  See block/blk-core:blk_errors for the details.
  73  * Alpha cannot write a byte atomically, so we need to use 32-bit value.
  74  */
  75 #if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
  76 typedef u32 __bitwise blk_status_t;
  77 #else
  78 typedef u8 __bitwise blk_status_t;
  79 #endif
  80 #define BLK_STS_OK 0
  81 #define BLK_STS_NOTSUPP         ((__force blk_status_t)1)
  82 #define BLK_STS_TIMEOUT         ((__force blk_status_t)2)
  83 #define BLK_STS_NOSPC           ((__force blk_status_t)3)
  84 #define BLK_STS_TRANSPORT       ((__force blk_status_t)4)
  85 #define BLK_STS_TARGET          ((__force blk_status_t)5)
  86 #define BLK_STS_NEXUS           ((__force blk_status_t)6)
  87 #define BLK_STS_MEDIUM          ((__force blk_status_t)7)
  88 #define BLK_STS_PROTECTION      ((__force blk_status_t)8)
  89 #define BLK_STS_RESOURCE        ((__force blk_status_t)9)
  90 #define BLK_STS_IOERR           ((__force blk_status_t)10)
  91
  92 /* hack for device mapper, don't use elsewhere: */
  93 #define BLK_STS_DM_REQUEUE    ((__force blk_status_t)11)
  94
  95 #define BLK_STS_AGAIN           ((__force blk_status_t)12)
  96
  97 /*
  98  * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
  99  * device related resources are unavailable, but the driver can guarantee
 100  * that the queue will be rerun in the future once resources become
 101  * available again. This is typically the case for device specific
 102  * resources that are consumed for IO. If the driver fails allocating these
 103  * resources, we know that inflight (or pending) IO will free these
 104  * resource upon completion.
 105  *
 106  * This is different from BLK_STS_RESOURCE in that it explicitly references
 107  * a device specific resource. For resources of wider scope, allocation
 108  * failure can happen without having pending IO. This means that we can't
 109  * rely on request completions freeing these resources, as IO may not be in
 110  * flight. Examples of that are kernel memory allocations, DMA mappings, or
 111  * any other system wide resources.
 112  */
 113 #define BLK_STS_DEV_RESOURCE    ((__force blk_status_t)13)
 114
 115 /*
 116  * BLK_STS_ZONE_RESOURCE is returned from the driver to the block layer if zone
 117  * related resources are unavailable, but the driver can guarantee the queue
 118  * will be rerun in the future once the resources become available again.
 119  *
 120  * This is different from BLK_STS_DEV_RESOURCE in that it explicitly references
 121  * a zone specific resource and IO to a different zone on the same device could
 122  * still be served. Examples of that are zones that are write-locked, but a read
 123  * to the same zone could be served.
 124  */
 125 #define BLK_STS_ZONE_RESOURCE   ((__force blk_status_t)14)
 126
 127 /*
 128  * BLK_STS_ZONE_OPEN_RESOURCE is returned from the driver in the completion
 129  * path if the device returns a status indicating that too many zone resources
 130  * are currently open. The same command should be successful if resubmitted
 131  * after the number of open zones decreases below the device's limits, which is
 132  * reported in the request_queue's max_open_zones.
 133  */
 134 #define BLK_STS_ZONE_OPEN_RESOURCE      ((__force blk_status_t)15)
 135
 136 /*
 137  * BLK_STS_ZONE_ACTIVE_RESOURCE is returned from the driver in the completion
 138  * path if the device returns a status indicating that too many zone resources
 139  * are currently active. The same command should be successful if resubmitted
 140  * after the number of active zones decreases below the device's limits, which
 141  * is reported in the request_queue's max_active_zones.
 142  */
 143 #define BLK_STS_ZONE_ACTIVE_RESOURCE    ((__force blk_status_t)16)
 144
 145 /**
 146  * blk_path_error - returns true if error may be path related
 147  * @error: status the request was completed with
 148  *
 149  * Description:
 150  *     This classifies block error status into non-retryable errors and ones
 151  *     that may be successful if retried on a failover path.
 152  *
 153  * Return:
 154  *     %false - retrying failover path will not help
 155  *     %true  - may succeed if retried
 156  */
 157 static inline bool blk_path_error(blk_status_t error)
 158 {
 159         switch (error) {
 160         case BLK_STS_NOTSUPP:
 161         case BLK_STS_NOSPC:
 162         case BLK_STS_TARGET:
 163         case BLK_STS_NEXUS:
 164         case BLK_STS_MEDIUM:
 165         case BLK_STS_PROTECTION:
 166                 return false;
 167         }
 168
 169         /* Anything else could be a path failure, so should be retried */
 170         return true;
 171 }
 172
 173 /*
 174  * From most significant bit:
 175  * 1 bit: reserved for other usage, see below
 176  * 12 bits: original size of bio
 177  * 51 bits: issue time of bio
 178  */
 179 #define BIO_ISSUE_RES_BITS      1
 180 #define BIO_ISSUE_SIZE_BITS     12
 181 #define BIO_ISSUE_RES_SHIFT     (64 - BIO_ISSUE_RES_BITS)
 182 #define BIO_ISSUE_SIZE_SHIFT    (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
 183 #define BIO_ISSUE_TIME_MASK     ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
 184 #define BIO_ISSUE_SIZE_MASK     \
 185         (((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
 186 #define BIO_ISSUE_RES_MASK      (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
 187
 188 /* Reserved bit for blk-throtl */
 189 #define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
 190
 191 struct bio_issue {
 192         u64 value;
 193 };
 194
 195 static inline u64 __bio_issue_time(u64 time)
 196 {
 197         return time & BIO_ISSUE_TIME_MASK;
 198 }
 199
 200 static inline u64 bio_issue_time(struct bio_issue *issue)
 201 {
 202         return __bio_issue_time(issue->value);
 203 }
 204
 205 static inline sector_t bio_issue_size(struct bio_issue *issue)
 206 {
 207         return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
 208 }
 209
 210 static inline void bio_issue_init(struct bio_issue *issue,
 211                                        sector_t size)
 212 {
 213         size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
 214         issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
 215                         (ktime_get_ns() & BIO_ISSUE_TIME_MASK) |
 216                         ((u64)size << BIO_ISSUE_SIZE_SHIFT));
 217 }
 218
 219 /*
 220  * main unit of I/O for the block layer and lower layers (ie drivers and
 221  * stacking drivers)
 222  */
 223 struct bio {
 224         struct bio              *bi_next;       /* request queue link */
 225         struct block_device     *bi_bdev;
 226         unsigned int            bi_opf;         /* bottom bits req flags,
 227                                                  * top bits REQ_OP. Use
 228                                                  * accessors.
 229                                                  */
 230         unsigned short          bi_flags;       /* BIO_* below */
 231         unsigned short          bi_ioprio;
 232         unsigned short          bi_write_hint;
 233         blk_status_t            bi_status;
 234         atomic_t                __bi_remaining;
 235
 236         struct bvec_iter        bi_iter;
 237
 238         bio_end_io_t            *bi_end_io;
 239
 240         void                    *bi_private;
 241 #ifdef CONFIG_BLK_CGROUP
 242         /*
 243          * Represents the association of the css and request_queue for the bio.
 244          * If a bio goes direct to device, it will not have a blkg as it will
 245          * not have a request_queue associated with it.  The reference is put
 246          * on release of the bio.
 247          */
 248         struct blkcg_gq         *bi_blkg;
 249         struct bio_issue        bi_issue;
 250 #ifdef CONFIG_BLK_CGROUP_IOCOST
 251         u64                     bi_iocost_cost;
 252 #endif
 253 #endif
 254
 255 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 256         struct bio_crypt_ctx    *bi_crypt_context;
 257 #endif
 258
 259         union {
 260 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 261                 struct bio_integrity_payload *bi_integrity; /* data integrity */
 262 #endif
 263         };
 264
 265         unsigned short          bi_vcnt;        /* how many bio_vec's */
 266
 267         /*
 268          * Everything starting with bi_max_vecs will be preserved by bio_reset()
 269          */
 270
 271         unsigned short          bi_max_vecs;    /* max bvl_vecs we can hold */
 272
 273         atomic_t                __bi_cnt;       /* pin count */
 274
 275         struct bio_vec          *bi_io_vec;     /* the actual vec list */
 276
 277         struct bio_set          *bi_pool;
 278
 279         /*
 280          * We can inline a number of vecs at the end of the bio, to avoid
 281          * double allocations for a small number of bio_vecs. This member
 282          * MUST obviously be kept at the very end of the bio.
 283          */
 284         struct bio_vec          bi_inline_vecs[];
 285 };
 286
 287 #define BIO_RESET_BYTES         offsetof(struct bio, bi_max_vecs)
 288
 289 /*
 290  * bio flags
 291  */
 292 enum {
 293         BIO_NO_PAGE_REF,        /* don't put release vec pages */
 294         BIO_CLONED,             /* doesn't own data */
 295         BIO_BOUNCED,            /* bio is a bounce bio */
 296         BIO_WORKINGSET,         /* contains userspace workingset pages */
 297         BIO_QUIET,              /* Make BIO Quiet */
 298         BIO_CHAIN,              /* chained bio, ->bi_remaining in effect */
 299         BIO_REFFED,             /* bio has elevated ->bi_cnt */
 300         BIO_THROTTLED,          /* This bio has already been subjected to
 301                                  * throttling rules. Don't do it again. */
 302         BIO_TRACE_COMPLETION,   /* bio_endio() should trace the final completion
 303                                  * of this bio. */
 304         BIO_CGROUP_ACCT,        /* has been accounted to a cgroup */
 305         BIO_TRACKED,            /* set if bio goes through the rq_qos path */
 306         BIO_REMAPPED,
 307         BIO_FLAG_LAST
 308 };
 309
 310 typedef __u32 __bitwise blk_mq_req_flags_t;
 311
 312 /*
 313  * Operations and flags common to the bio and request structures.
 314  * We use 8 bits for encoding the operation, and the remaining 24 for flags.
 315  *
 316  * The least significant bit of the operation number indicates the data
 317  * transfer direction:
 318  *
 319  *   - if the least significant bit is set transfers are TO the device
 320  *   - if the least significant bit is not set transfers are FROM the device
 321  *
 322  * If a operation does not transfer data the least significant bit has no
 323  * meaning.
 324  */
 325 #define REQ_OP_BITS     8
 326 #define REQ_OP_MASK     ((1 << REQ_OP_BITS) - 1)
 327 #define REQ_FLAG_BITS   24
 328
 329 enum req_opf {
 330         /* read sectors from the device */
 331         REQ_OP_READ             = 0,
 332         /* write sectors to the device */
 333         REQ_OP_WRITE            = 1,
 334         /* flush the volatile write cache */
 335         REQ_OP_FLUSH            = 2,
 336         /* discard sectors */
 337         REQ_OP_DISCARD          = 3,
 338         /* securely erase sectors */
 339         REQ_OP_SECURE_ERASE     = 5,
 340         /* write the same sector many times */
 341         REQ_OP_WRITE_SAME       = 7,
 342         /* write the zero filled sector many times */
 343         REQ_OP_WRITE_ZEROES     = 9,
 344         /* Open a zone */
 345         REQ_OP_ZONE_OPEN        = 10,
 346         /* Close a zone */
 347         REQ_OP_ZONE_CLOSE       = 11,
 348         /* Transition a zone to full */
 349         REQ_OP_ZONE_FINISH      = 12,
 350         /* write data at the current zone write pointer */
 351         REQ_OP_ZONE_APPEND      = 13,
 352         /* reset a zone write pointer */
 353         REQ_OP_ZONE_RESET       = 15,
 354         /* reset all the zone present on the device */
 355         REQ_OP_ZONE_RESET_ALL   = 17,
 356
 357         /* SCSI passthrough using struct scsi_request */
 358         REQ_OP_SCSI_IN          = 32,
 359         REQ_OP_SCSI_OUT         = 33,
 360         /* Driver private requests */
 361         REQ_OP_DRV_IN           = 34,
 362         REQ_OP_DRV_OUT          = 35,
 363
 364         REQ_OP_LAST,
 365 };
 366
 367 enum req_flag_bits {
 368         __REQ_FAILFAST_DEV =    /* no driver retries of device errors */
 369                 REQ_OP_BITS,
 370         __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
 371         __REQ_FAILFAST_DRIVER,  /* no driver retries of driver errors */
 372         __REQ_SYNC,             /* request is sync (sync write or read) */
 373         __REQ_META,             /* metadata io request */
 374         __REQ_PRIO,             /* boost priority in cfq */
 375         __REQ_NOMERGE,          /* don't touch this for merging */
 376         __REQ_IDLE,             /* anticipate more IO after this one */
 377         __REQ_INTEGRITY,        /* I/O includes block integrity payload */
 378         __REQ_FUA,              /* forced unit access */
 379         __REQ_PREFLUSH,         /* request for cache flush */
 380         __REQ_RAHEAD,           /* read ahead, can fail anytime */
 381         __REQ_BACKGROUND,       /* background IO */
 382         __REQ_NOWAIT,           /* Don't wait if request will block */
 383         /*
 384          * When a shared kthread needs to issue a bio for a cgroup, doing
 385          * so synchronously can lead to priority inversions as the kthread
 386          * can be trapped waiting for that cgroup.  CGROUP_PUNT flag makes
 387          * submit_bio() punt the actual issuing to a dedicated per-blkcg
 388          * work item to avoid such priority inversions.
 389          */
 390         __REQ_CGROUP_PUNT,
 391
 392         /* command specific flags for REQ_OP_WRITE_ZEROES: */
 393         __REQ_NOUNMAP,          /* do not free blocks when zeroing */
 394
 395         __REQ_HIPRI,
 396
 397         /* for driver use */
 398         __REQ_DRV,
 399         __REQ_SWAP,             /* swapping request. */
 400         __REQ_NR_BITS,          /* stops here */
 401 };
 402
 403 #define REQ_FAILFAST_DEV        (1ULL << __REQ_FAILFAST_DEV)
 404 #define REQ_FAILFAST_TRANSPORT  (1ULL << __REQ_FAILFAST_TRANSPORT)
 405 #define REQ_FAILFAST_DRIVER     (1ULL << __REQ_FAILFAST_DRIVER)
 406 #define REQ_SYNC                (1ULL << __REQ_SYNC)
 407 #define REQ_META                (1ULL << __REQ_META)
 408 #define REQ_PRIO                (1ULL << __REQ_PRIO)
 409 #define REQ_NOMERGE             (1ULL << __REQ_NOMERGE)
 410 #define REQ_IDLE                (1ULL << __REQ_IDLE)
 411 #define REQ_INTEGRITY           (1ULL << __REQ_INTEGRITY)
 412 #define REQ_FUA                 (1ULL << __REQ_FUA)
 413 #define REQ_PREFLUSH            (1ULL << __REQ_PREFLUSH)
 414 #define REQ_RAHEAD              (1ULL << __REQ_RAHEAD)
 415 #define REQ_BACKGROUND          (1ULL << __REQ_BACKGROUND)
 416 #define REQ_NOWAIT              (1ULL << __REQ_NOWAIT)
 417 #define REQ_CGROUP_PUNT         (1ULL << __REQ_CGROUP_PUNT)
 418
 419 #define REQ_NOUNMAP             (1ULL << __REQ_NOUNMAP)
 420 #define REQ_HIPRI               (1ULL << __REQ_HIPRI)
 421
 422 #define REQ_DRV                 (1ULL << __REQ_DRV)
 423 #define REQ_SWAP                (1ULL << __REQ_SWAP)
 424
 425 #define REQ_FAILFAST_MASK \
 426         (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 427
 428 #define REQ_NOMERGE_FLAGS \
 429         (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
 430
 431 enum stat_group {
 432         STAT_READ,
 433         STAT_WRITE,
 434         STAT_DISCARD,
 435         STAT_FLUSH,
 436
 437         NR_STAT_GROUPS
 438 };
 439
 440 #define bio_op(bio) \
 441         ((bio)->bi_opf & REQ_OP_MASK)
 442 #define req_op(req) \
 443         ((req)->cmd_flags & REQ_OP_MASK)
 444
 445 /* obsolete, don't use in new code */
 446 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
 447                 unsigned op_flags)
 448 {
 449         bio->bi_opf = op | op_flags;
 450 }
 451
 452 static inline bool op_is_write(unsigned int op)
 453 {
 454         return (op & 1);
 455 }
 456
 457 /*
 458  * Check if the bio or request is one that needs special treatment in the
 459  * flush state machine.
 460  */
 461 static inline bool op_is_flush(unsigned int op)
 462 {
 463         return op & (REQ_FUA | REQ_PREFLUSH);
 464 }
 465
 466 /*
 467  * Reads are always treated as synchronous, as are requests with the FUA or
 468  * PREFLUSH flag.  Other operations may be marked as synchronous using the
 469  * REQ_SYNC flag.
 470  */
 471 static inline bool op_is_sync(unsigned int op)
 472 {
 473         return (op & REQ_OP_MASK) == REQ_OP_READ ||
 474                 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
 475 }
 476
 477 static inline bool op_is_discard(unsigned int op)
 478 {
 479         return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
 480 }
 481
 482 /*
 483  * Check if a bio or request operation is a zone management operation, with
 484  * the exception of REQ_OP_ZONE_RESET_ALL which is treated as a special case
 485  * due to its different handling in the block layer and device response in
 486  * case of command failure.
 487  */
 488 static inline bool op_is_zone_mgmt(enum req_opf op)
 489 {
 490         switch (op & REQ_OP_MASK) {
 491         case REQ_OP_ZONE_RESET:
 492         case REQ_OP_ZONE_OPEN:
 493         case REQ_OP_ZONE_CLOSE:
 494         case REQ_OP_ZONE_FINISH:
 495                 return true;
 496         default:
 497                 return false;
 498         }
 499 }
 500
 501 static inline int op_stat_group(unsigned int op)
 502 {
 503         if (op_is_discard(op))
 504                 return STAT_DISCARD;
 505         return op_is_write(op);
 506 }
 507
 508 typedef unsigned int blk_qc_t;
 509 #define BLK_QC_T_NONE           -1U
 510 #define BLK_QC_T_SHIFT          16
 511 #define BLK_QC_T_INTERNAL       (1U << 31)
 512
 513 static inline bool blk_qc_t_valid(blk_qc_t cookie)
 514 {
 515         return cookie != BLK_QC_T_NONE;
 516 }
 517
 518 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
 519 {
 520         return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
 521 }
 522
 523 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
 524 {
 525         return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
 526 }
 527
 528 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
 529 {
 530         return (cookie & BLK_QC_T_INTERNAL) != 0;
 531 }
 532
 533 struct blk_rq_stat {
 534         u64 mean;
 535         u64 min;
 536         u64 max;
 537         u32 nr_samples;
 538         u64 batch;
 539 };
 540
 541 #endif /* __LINUX_BLK_TYPES_H */