include/linux/blkdev.h

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
blk_op_is_scsi
blk_op_is_private
blk_rq_is_scsi
blk_rq_is_private
blk_rq_is_passthrough
bio_is_passthrough
req_get_ioprio
blkdev_nr_zones
blk_revalidate_disk_zones
blkdev_report_zones_ioctl
blkdev_reset_zones_ioctl
blk_account_rq
queue_is_mq
blk_queue_zoned_model
blk_queue_is_zoned
blk_queue_zone_sectors
blk_queue_nr_zones
blk_queue_zone_no
blk_queue_zone_is_seq
blk_queue_nr_zones
rq_is_sync
rq_mergeable
blk_write_same_mergeable
blk_queue_depth
rq_flush_dcache_pages
bdev_get_queue
blk_rq_pos
blk_rq_bytes
blk_rq_cur_bytes
blk_rq_sectors
blk_rq_cur_sectors
blk_rq_stats_sectors
blk_rq_zone_no
blk_rq_zone_is_seq
blk_rq_payload_bytes
req_bvec
blk_queue_get_max_sectors
blk_max_size_offset
blk_rq_get_max_sectors
blk_rq_count_bios
blk_rq_nr_phys_segments
blk_rq_nr_discard_segments
blk_flush_plug
blk_schedule_flush_plug
blk_needs_flush_plug
sb_issue_discard
sb_issue_zeroout
queue_segment_boundary
queue_virt_boundary
queue_max_sectors
queue_max_hw_sectors
queue_max_segments
queue_max_discard_segments
queue_max_segment_size
queue_logical_block_size
bdev_logical_block_size
queue_physical_block_size
bdev_physical_block_size
queue_io_min
bdev_io_min
queue_io_opt
bdev_io_opt
queue_alignment_offset
queue_limit_alignment_offset
bdev_alignment_offset
queue_discard_alignment
queue_limit_discard_alignment
bdev_discard_alignment
bdev_write_same
bdev_write_zeroes_sectors
bdev_zoned_model
bdev_is_zoned
bdev_zone_sectors
queue_dma_alignment
blk_rq_aligned
blksize_bits
block_size
put_dev_sector
blk_get_integrity
bdev_get_integrity
blk_integrity_rq
blk_queue_max_integrity_segments
queue_max_integrity_segments
bio_integrity_intervals
bio_integrity_bytes
rq_integrity_vec
blk_integrity_rq
blk_rq_count_integrity_sg
blk_rq_map_integrity_sg
bdev_get_integrity
blk_get_integrity
blk_integrity_compare
blk_integrity_register
blk_integrity_unregister
blk_queue_max_integrity_segments
queue_max_integrity_segments
blk_integrity_merge_rq
blk_integrity_merge_bio
bio_integrity_intervals
bio_integrity_bytes
rq_integrity_vec
blk_req_zone_write_lock
blk_req_zone_write_unlock
blk_req_zone_is_write_locked
blk_req_can_dispatch_to_zone
blk_req_needs_zone_write_lock
blk_req_zone_write_lock
blk_req_zone_write_unlock
blk_req_zone_is_write_locked
blk_req_can_dispatch_to_zone
nr_blockdev_pages
blk_start_plug
blk_finish_plug
blk_flush_plug
blk_schedule_flush_plug
blk_needs_flush_plug
blkdev_issue_flush
blk_wake_io_task
   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_BLKDEV_H
   3 #define _LINUX_BLKDEV_H
   4 
   5 #include <linux/sched.h>
   6 #include <linux/sched/clock.h>
   7 
   8 #ifdef CONFIG_BLOCK
   9 
  10 #include <linux/major.h>
  11 #include <linux/genhd.h>
  12 #include <linux/list.h>
  13 #include <linux/llist.h>
  14 #include <linux/timer.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/backing-dev-defs.h>
  18 #include <linux/wait.h>
  19 #include <linux/mempool.h>
  20 #include <linux/pfn.h>
  21 #include <linux/bio.h>
  22 #include <linux/stringify.h>
  23 #include <linux/gfp.h>
  24 #include <linux/bsg.h>
  25 #include <linux/smp.h>
  26 #include <linux/rcupdate.h>
  27 #include <linux/percpu-refcount.h>
  28 #include <linux/scatterlist.h>
  29 #include <linux/blkzoned.h>
  30 
  31 struct module;
  32 struct scsi_ioctl_command;
  33 
  34 struct request_queue;
  35 struct elevator_queue;
  36 struct blk_trace;
  37 struct request;
  38 struct sg_io_hdr;
  39 struct bsg_job;
  40 struct blkcg_gq;
  41 struct blk_flush_queue;
  42 struct pr_ops;
  43 struct rq_qos;
  44 struct blk_queue_stats;
  45 struct blk_stat_callback;
  46 
  47 #define BLKDEV_MIN_RQ   4
  48 #define BLKDEV_MAX_RQ   128     /* Default maximum */
  49 
  50 /* Must be consistent with blk_mq_poll_stats_bkt() */
  51 #define BLK_MQ_POLL_STATS_BKTS 16
  52 
  53 /* Doing classic polling */
  54 #define BLK_MQ_POLL_CLASSIC -1
  55 
  56 /*
  57  * Maximum number of blkcg policies allowed to be registered concurrently.
  58  * Defined here to simplify include dependency.
  59  */
  60 #define BLKCG_MAX_POLS          5
  61 
  62 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
  63 
  64 /*
  65  * request flags */
  66 typedef __u32 __bitwise req_flags_t;
  67 
  68 /* elevator knows about this request */
  69 #define RQF_SORTED              ((__force req_flags_t)(1 << 0))
  70 /* drive already may have started this one */
  71 #define RQF_STARTED             ((__force req_flags_t)(1 << 1))
  72 /* may not be passed by ioscheduler */
  73 #define RQF_SOFTBARRIER         ((__force req_flags_t)(1 << 3))
  74 /* request for flush sequence */
  75 #define RQF_FLUSH_SEQ           ((__force req_flags_t)(1 << 4))
  76 /* merge of different types, fail separately */
  77 #define RQF_MIXED_MERGE         ((__force req_flags_t)(1 << 5))
  78 /* track inflight for MQ */
  79 #define RQF_MQ_INFLIGHT         ((__force req_flags_t)(1 << 6))
  80 /* don't call prep for this one */
  81 #define RQF_DONTPREP            ((__force req_flags_t)(1 << 7))
  82 /* set for "ide_preempt" requests and also for requests for which the SCSI
  83    "quiesce" state must be ignored. */
  84 #define RQF_PREEMPT             ((__force req_flags_t)(1 << 8))
  85 /* contains copies of user pages */
  86 #define RQF_COPY_USER           ((__force req_flags_t)(1 << 9))
  87 /* vaguely specified driver internal error.  Ignored by the block layer */
  88 #define RQF_FAILED              ((__force req_flags_t)(1 << 10))
  89 /* don't warn about errors */
  90 #define RQF_QUIET               ((__force req_flags_t)(1 << 11))
  91 /* elevator private data attached */
  92 #define RQF_ELVPRIV             ((__force req_flags_t)(1 << 12))
  93 /* account into disk and partition IO statistics */
  94 #define RQF_IO_STAT             ((__force req_flags_t)(1 << 13))
  95 /* request came from our alloc pool */
  96 #define RQF_ALLOCED             ((__force req_flags_t)(1 << 14))
  97 /* runtime pm request */
  98 #define RQF_PM                  ((__force req_flags_t)(1 << 15))
  99 /* on IO scheduler merge hash */
 100 #define RQF_HASHED              ((__force req_flags_t)(1 << 16))
 101 /* track IO completion time */
 102 #define RQF_STATS               ((__force req_flags_t)(1 << 17))
 103 /* Look at ->special_vec for the actual data payload instead of the
 104    bio chain. */
 105 #define RQF_SPECIAL_PAYLOAD     ((__force req_flags_t)(1 << 18))
 106 /* The per-zone write lock is held for this request */
 107 #define RQF_ZONE_WRITE_LOCKED   ((__force req_flags_t)(1 << 19))
 108 /* already slept for hybrid poll */
 109 #define RQF_MQ_POLL_SLEPT       ((__force req_flags_t)(1 << 20))
 110 /* ->timeout has been called, don't expire again */
 111 #define RQF_TIMED_OUT           ((__force req_flags_t)(1 << 21))
 112 
 113 /* flags that prevent us from merging requests: */
 114 #define RQF_NOMERGE_FLAGS \
 115         (RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
 116 
 117 /*
 118  * Request state for blk-mq.
 119  */
 120 enum mq_rq_state {
 121         MQ_RQ_IDLE              = 0,
 122         MQ_RQ_IN_FLIGHT         = 1,
 123         MQ_RQ_COMPLETE          = 2,
 124 };
 125 
 126 /*
 127  * Try to put the fields that are referenced together in the same cacheline.
 128  *
 129  * If you modify this structure, make sure to update blk_rq_init() and
 130  * especially blk_mq_rq_ctx_init() to take care of the added fields.
 131  */
 132 struct request {
 133         struct request_queue *q;
 134         struct blk_mq_ctx *mq_ctx;
 135         struct blk_mq_hw_ctx *mq_hctx;
 136 
 137         unsigned int cmd_flags;         /* op and common flags */
 138         req_flags_t rq_flags;
 139 
 140         int tag;
 141         int internal_tag;
 142 
 143         /* the following two fields are internal, NEVER access directly */
 144         unsigned int __data_len;        /* total data len */
 145         sector_t __sector;              /* sector cursor */
 146 
 147         struct bio *bio;
 148         struct bio *biotail;
 149 
 150         struct list_head queuelist;
 151 
 152         /*
 153          * The hash is used inside the scheduler, and killed once the
 154          * request reaches the dispatch list. The ipi_list is only used
 155          * to queue the request for softirq completion, which is long
 156          * after the request has been unhashed (and even removed from
 157          * the dispatch list).
 158          */
 159         union {
 160                 struct hlist_node hash; /* merge hash */
 161                 struct list_head ipi_list;
 162         };
 163 
 164         /*
 165          * The rb_node is only used inside the io scheduler, requests
 166          * are pruned when moved to the dispatch queue. So let the
 167          * completion_data share space with the rb_node.
 168          */
 169         union {
 170                 struct rb_node rb_node; /* sort/lookup */
 171                 struct bio_vec special_vec;
 172                 void *completion_data;
 173                 int error_count; /* for legacy drivers, don't use */
 174         };
 175 
 176         /*
 177          * Three pointers are available for the IO schedulers, if they need
 178          * more they have to dynamically allocate it.  Flush requests are
 179          * never put on the IO scheduler. So let the flush fields share
 180          * space with the elevator data.
 181          */
 182         union {
 183                 struct {
 184                         struct io_cq            *icq;
 185                         void                    *priv[2];
 186                 } elv;
 187 
 188                 struct {
 189                         unsigned int            seq;
 190                         struct list_head        list;
 191                         rq_end_io_fn            *saved_end_io;
 192                 } flush;
 193         };
 194 
 195         struct gendisk *rq_disk;
 196         struct hd_struct *part;
 197 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
 198         /* Time that the first bio started allocating this request. */
 199         u64 alloc_time_ns;
 200 #endif
 201         /* Time that this request was allocated for this IO. */
 202         u64 start_time_ns;
 203         /* Time that I/O was submitted to the device. */
 204         u64 io_start_time_ns;
 205 
 206 #ifdef CONFIG_BLK_WBT
 207         unsigned short wbt_flags;
 208 #endif
 209         /*
 210          * rq sectors used for blk stats. It has the same value
 211          * with blk_rq_sectors(rq), except that it never be zeroed
 212          * by completion.
 213          */
 214         unsigned short stats_sectors;
 215 
 216         /*
 217          * Number of scatter-gather DMA addr+len pairs after
 218          * physical address coalescing is performed.
 219          */
 220         unsigned short nr_phys_segments;
 221 
 222 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 223         unsigned short nr_integrity_segments;
 224 #endif
 225 
 226         unsigned short write_hint;
 227         unsigned short ioprio;
 228 
 229         unsigned int extra_len; /* length of alignment and padding */
 230 
 231         enum mq_rq_state state;
 232         refcount_t ref;
 233 
 234         unsigned int timeout;
 235         unsigned long deadline;
 236 
 237         union {
 238                 struct __call_single_data csd;
 239                 u64 fifo_time;
 240         };
 241 
 242         /*
 243          * completion callback.
 244          */
 245         rq_end_io_fn *end_io;
 246         void *end_io_data;
 247 };
 248 
 249 static inline bool blk_op_is_scsi(unsigned int op)
 250 {
 251         return op == REQ_OP_SCSI_IN || op == REQ_OP_SCSI_OUT;
 252 }
 253 
 254 static inline bool blk_op_is_private(unsigned int op)
 255 {
 256         return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
 257 }
 258 
 259 static inline bool blk_rq_is_scsi(struct request *rq)
 260 {
 261         return blk_op_is_scsi(req_op(rq));
 262 }
 263 
 264 static inline bool blk_rq_is_private(struct request *rq)
 265 {
 266         return blk_op_is_private(req_op(rq));
 267 }
 268 
 269 static inline bool blk_rq_is_passthrough(struct request *rq)
 270 {
 271         return blk_rq_is_scsi(rq) || blk_rq_is_private(rq);
 272 }
 273 
 274 static inline bool bio_is_passthrough(struct bio *bio)
 275 {
 276         unsigned op = bio_op(bio);
 277 
 278         return blk_op_is_scsi(op) || blk_op_is_private(op);
 279 }
 280 
 281 static inline unsigned short req_get_ioprio(struct request *req)
 282 {
 283         return req->ioprio;
 284 }
 285 
 286 #include <linux/elevator.h>
 287 
 288 struct blk_queue_ctx;
 289 
 290 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
 291 
 292 struct bio_vec;
 293 typedef int (dma_drain_needed_fn)(struct request *);
 294 
 295 enum blk_eh_timer_return {
 296         BLK_EH_DONE,            /* drivers has completed the command */
 297         BLK_EH_RESET_TIMER,     /* reset timer and try again */
 298 };
 299 
 300 enum blk_queue_state {
 301         Queue_down,
 302         Queue_up,
 303 };
 304 
 305 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
 306 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
 307 
 308 #define BLK_SCSI_MAX_CMDS       (256)
 309 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 310 
 311 /*
 312  * Zoned block device models (zoned limit).
 313  */
 314 enum blk_zoned_model {
 315         BLK_ZONED_NONE, /* Regular block device */
 316         BLK_ZONED_HA,   /* Host-aware zoned block device */
 317         BLK_ZONED_HM,   /* Host-managed zoned block device */
 318 };
 319 
 320 struct queue_limits {
 321         unsigned long           bounce_pfn;
 322         unsigned long           seg_boundary_mask;
 323         unsigned long           virt_boundary_mask;
 324 
 325         unsigned int            max_hw_sectors;
 326         unsigned int            max_dev_sectors;
 327         unsigned int            chunk_sectors;
 328         unsigned int            max_sectors;
 329         unsigned int            max_segment_size;
 330         unsigned int            physical_block_size;
 331         unsigned int            logical_block_size;
 332         unsigned int            alignment_offset;
 333         unsigned int            io_min;
 334         unsigned int            io_opt;
 335         unsigned int            max_discard_sectors;
 336         unsigned int            max_hw_discard_sectors;
 337         unsigned int            max_write_same_sectors;
 338         unsigned int            max_write_zeroes_sectors;
 339         unsigned int            discard_granularity;
 340         unsigned int            discard_alignment;
 341 
 342         unsigned short          max_segments;
 343         unsigned short          max_integrity_segments;
 344         unsigned short          max_discard_segments;
 345 
 346         unsigned char           misaligned;
 347         unsigned char           discard_misaligned;
 348         unsigned char           raid_partial_stripes_expensive;
 349         enum blk_zoned_model    zoned;
 350 };
 351 
 352 #ifdef CONFIG_BLK_DEV_ZONED
 353 
 354 /*
 355  * Maximum number of zones to report with a single report zones command.
 356  */
 357 #define BLK_ZONED_REPORT_MAX_ZONES      8192U
 358 
 359 extern unsigned int blkdev_nr_zones(struct block_device *bdev);
 360 extern int blkdev_report_zones(struct block_device *bdev,
 361                                sector_t sector, struct blk_zone *zones,
 362                                unsigned int *nr_zones);
 363 extern int blkdev_reset_zones(struct block_device *bdev, sector_t sectors,
 364                               sector_t nr_sectors, gfp_t gfp_mask);
 365 extern int blk_revalidate_disk_zones(struct gendisk *disk);
 366 
 367 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
 368                                      unsigned int cmd, unsigned long arg);
 369 extern int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
 370                                     unsigned int cmd, unsigned long arg);
 371 
 372 #else /* CONFIG_BLK_DEV_ZONED */
 373 
 374 static inline unsigned int blkdev_nr_zones(struct block_device *bdev)
 375 {
 376         return 0;
 377 }
 378 
 379 static inline int blk_revalidate_disk_zones(struct gendisk *disk)
 380 {
 381         return 0;
 382 }
 383 
 384 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
 385                                             fmode_t mode, unsigned int cmd,
 386                                             unsigned long arg)
 387 {
 388         return -ENOTTY;
 389 }
 390 
 391 static inline int blkdev_reset_zones_ioctl(struct block_device *bdev,
 392                                            fmode_t mode, unsigned int cmd,
 393                                            unsigned long arg)
 394 {
 395         return -ENOTTY;
 396 }
 397 
 398 #endif /* CONFIG_BLK_DEV_ZONED */
 399 
 400 struct request_queue {
 401         struct request          *last_merge;
 402         struct elevator_queue   *elevator;
 403 
 404         struct blk_queue_stats  *stats;
 405         struct rq_qos           *rq_qos;
 406 
 407         make_request_fn         *make_request_fn;
 408         dma_drain_needed_fn     *dma_drain_needed;
 409 
 410         const struct blk_mq_ops *mq_ops;
 411 
 412         /* sw queues */
 413         struct blk_mq_ctx __percpu      *queue_ctx;
 414         unsigned int            nr_queues;
 415 
 416         unsigned int            queue_depth;
 417 
 418         /* hw dispatch queues */
 419         struct blk_mq_hw_ctx    **queue_hw_ctx;
 420         unsigned int            nr_hw_queues;
 421 
 422         struct backing_dev_info *backing_dev_info;
 423 
 424         /*
 425          * The queue owner gets to use this for whatever they like.
 426          * ll_rw_blk doesn't touch it.
 427          */
 428         void                    *queuedata;
 429 
 430         /*
 431          * various queue flags, see QUEUE_* below
 432          */
 433         unsigned long           queue_flags;
 434         /*
 435          * Number of contexts that have called blk_set_pm_only(). If this
 436          * counter is above zero then only RQF_PM and RQF_PREEMPT requests are
 437          * processed.
 438          */
 439         atomic_t                pm_only;
 440 
 441         /*
 442          * ida allocated id for this queue.  Used to index queues from
 443          * ioctx.
 444          */
 445         int                     id;
 446 
 447         /*
 448          * queue needs bounce pages for pages above this limit
 449          */
 450         gfp_t                   bounce_gfp;
 451 
 452         spinlock_t              queue_lock;
 453 
 454         /*
 455          * queue kobject
 456          */
 457         struct kobject kobj;
 458 
 459         /*
 460          * mq queue kobject
 461          */
 462         struct kobject *mq_kobj;
 463 
 464 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 465         struct blk_integrity integrity;
 466 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 467 
 468 #ifdef CONFIG_PM
 469         struct device           *dev;
 470         int                     rpm_status;
 471         unsigned int            nr_pending;
 472 #endif
 473 
 474         /*
 475          * queue settings
 476          */
 477         unsigned long           nr_requests;    /* Max # of requests */
 478 
 479         unsigned int            dma_drain_size;
 480         void                    *dma_drain_buffer;
 481         unsigned int            dma_pad_mask;
 482         unsigned int            dma_alignment;
 483 
 484         unsigned int            rq_timeout;
 485         int                     poll_nsec;
 486 
 487         struct blk_stat_callback        *poll_cb;
 488         struct blk_rq_stat      poll_stat[BLK_MQ_POLL_STATS_BKTS];
 489 
 490         struct timer_list       timeout;
 491         struct work_struct      timeout_work;
 492 
 493         struct list_head        icq_list;
 494 #ifdef CONFIG_BLK_CGROUP
 495         DECLARE_BITMAP          (blkcg_pols, BLKCG_MAX_POLS);
 496         struct blkcg_gq         *root_blkg;
 497         struct list_head        blkg_list;
 498 #endif
 499 
 500         struct queue_limits     limits;
 501 
 502         unsigned int            required_elevator_features;
 503 
 504 #ifdef CONFIG_BLK_DEV_ZONED
 505         /*
 506          * Zoned block device information for request dispatch control.
 507          * nr_zones is the total number of zones of the device. This is always
 508          * 0 for regular block devices. seq_zones_bitmap is a bitmap of nr_zones
 509          * bits which indicates if a zone is conventional (bit clear) or
 510          * sequential (bit set). seq_zones_wlock is a bitmap of nr_zones
 511          * bits which indicates if a zone is write locked, that is, if a write
 512          * request targeting the zone was dispatched. All three fields are
 513          * initialized by the low level device driver (e.g. scsi/sd.c).
 514          * Stacking drivers (device mappers) may or may not initialize
 515          * these fields.
 516          *
 517          * Reads of this information must be protected with blk_queue_enter() /
 518          * blk_queue_exit(). Modifying this information is only allowed while
 519          * no requests are being processed. See also blk_mq_freeze_queue() and
 520          * blk_mq_unfreeze_queue().
 521          */
 522         unsigned int            nr_zones;
 523         unsigned long           *seq_zones_bitmap;
 524         unsigned long           *seq_zones_wlock;
 525 #endif /* CONFIG_BLK_DEV_ZONED */
 526 
 527         /*
 528          * sg stuff
 529          */
 530         unsigned int            sg_timeout;
 531         unsigned int            sg_reserved_size;
 532         int                     node;
 533 #ifdef CONFIG_BLK_DEV_IO_TRACE
 534         struct blk_trace __rcu  *blk_trace;
 535         struct mutex            blk_trace_mutex;
 536 #endif
 537         /*
 538          * for flush operations
 539          */
 540         struct blk_flush_queue  *fq;
 541 
 542         struct list_head        requeue_list;
 543         spinlock_t              requeue_lock;
 544         struct delayed_work     requeue_work;
 545 
 546         struct mutex            sysfs_lock;
 547         struct mutex            sysfs_dir_lock;
 548 
 549         /*
 550          * for reusing dead hctx instance in case of updating
 551          * nr_hw_queues
 552          */
 553         struct list_head        unused_hctx_list;
 554         spinlock_t              unused_hctx_lock;
 555 
 556         int                     mq_freeze_depth;
 557 
 558 #if defined(CONFIG_BLK_DEV_BSG)
 559         struct bsg_class_device bsg_dev;
 560 #endif
 561 
 562 #ifdef CONFIG_BLK_DEV_THROTTLING
 563         /* Throttle data */
 564         struct throtl_data *td;
 565 #endif
 566         struct rcu_head         rcu_head;
 567         wait_queue_head_t       mq_freeze_wq;
 568         /*
 569          * Protect concurrent access to q_usage_counter by
 570          * percpu_ref_kill() and percpu_ref_reinit().
 571          */
 572         struct mutex            mq_freeze_lock;
 573         struct percpu_ref       q_usage_counter;
 574 
 575         struct blk_mq_tag_set   *tag_set;
 576         struct list_head        tag_set_list;
 577         struct bio_set          bio_split;
 578 
 579 #ifdef CONFIG_BLK_DEBUG_FS
 580         struct dentry           *debugfs_dir;
 581         struct dentry           *sched_debugfs_dir;
 582         struct dentry           *rqos_debugfs_dir;
 583 #endif
 584 
 585         bool                    mq_sysfs_init_done;
 586 
 587         size_t                  cmd_size;
 588 
 589         struct work_struct      release_work;
 590 
 591 #define BLK_MAX_WRITE_HINTS     5
 592         u64                     write_hints[BLK_MAX_WRITE_HINTS];
 593 };
 594 
 595 #define QUEUE_FLAG_STOPPED      0       /* queue is stopped */
 596 #define QUEUE_FLAG_DYING        1       /* queue being torn down */
 597 #define QUEUE_FLAG_NOMERGES     3       /* disable merge attempts */
 598 #define QUEUE_FLAG_SAME_COMP    4       /* complete on same CPU-group */
 599 #define QUEUE_FLAG_FAIL_IO      5       /* fake timeout */
 600 #define QUEUE_FLAG_NONROT       6       /* non-rotational device (SSD) */
 601 #define QUEUE_FLAG_VIRT         QUEUE_FLAG_NONROT /* paravirt device */
 602 #define QUEUE_FLAG_IO_STAT      7       /* do disk/partitions IO accounting */
 603 #define QUEUE_FLAG_DISCARD      8       /* supports DISCARD */
 604 #define QUEUE_FLAG_NOXMERGES    9       /* No extended merges */
 605 #define QUEUE_FLAG_ADD_RANDOM   10      /* Contributes to random pool */
 606 #define QUEUE_FLAG_SECERASE     11      /* supports secure erase */
 607 #define QUEUE_FLAG_SAME_FORCE   12      /* force complete on same CPU */
 608 #define QUEUE_FLAG_DEAD         13      /* queue tear-down finished */
 609 #define QUEUE_FLAG_INIT_DONE    14      /* queue is initialized */
 610 #define QUEUE_FLAG_POLL         16      /* IO polling enabled if set */
 611 #define QUEUE_FLAG_WC           17      /* Write back caching */
 612 #define QUEUE_FLAG_FUA          18      /* device supports FUA writes */
 613 #define QUEUE_FLAG_DAX          19      /* device supports DAX */
 614 #define QUEUE_FLAG_STATS        20      /* track IO start and completion times */
 615 #define QUEUE_FLAG_POLL_STATS   21      /* collecting stats for hybrid polling */
 616 #define QUEUE_FLAG_REGISTERED   22      /* queue has been registered to a disk */
 617 #define QUEUE_FLAG_SCSI_PASSTHROUGH 23  /* queue supports SCSI commands */
 618 #define QUEUE_FLAG_QUIESCED     24      /* queue has been quiesced */
 619 #define QUEUE_FLAG_PCI_P2PDMA   25      /* device supports PCI p2p requests */
 620 #define QUEUE_FLAG_ZONE_RESETALL 26     /* supports Zone Reset All */
 621 #define QUEUE_FLAG_RQ_ALLOC_TIME 27     /* record rq->alloc_time_ns */
 622 
 623 #define QUEUE_FLAG_MQ_DEFAULT   ((1 << QUEUE_FLAG_IO_STAT) |            \
 624                                  (1 << QUEUE_FLAG_SAME_COMP))
 625 
 626 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
 627 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
 628 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
 629 
 630 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 631 #define blk_queue_dying(q)      test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
 632 #define blk_queue_dead(q)       test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
 633 #define blk_queue_init_done(q)  test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
 634 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 635 #define blk_queue_noxmerges(q)  \
 636         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 637 #define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 638 #define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
 639 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
 640 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
 641 #define blk_queue_zone_resetall(q)      \
 642         test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
 643 #define blk_queue_secure_erase(q) \
 644         (test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
 645 #define blk_queue_dax(q)        test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
 646 #define blk_queue_scsi_passthrough(q)   \
 647         test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
 648 #define blk_queue_pci_p2pdma(q) \
 649         test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
 650 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
 651 #define blk_queue_rq_alloc_time(q)      \
 652         test_bit(QUEUE_FLAG_RQ_ALLOC_TIME, &(q)->queue_flags)
 653 #else
 654 #define blk_queue_rq_alloc_time(q)      false
 655 #endif
 656 
 657 #define blk_noretry_request(rq) \
 658         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
 659                              REQ_FAILFAST_DRIVER))
 660 #define blk_queue_quiesced(q)   test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
 661 #define blk_queue_pm_only(q)    atomic_read(&(q)->pm_only)
 662 #define blk_queue_fua(q)        test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
 663 #define blk_queue_registered(q) test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
 664 
 665 extern void blk_set_pm_only(struct request_queue *q);
 666 extern void blk_clear_pm_only(struct request_queue *q);
 667 
 668 static inline bool blk_account_rq(struct request *rq)
 669 {
 670         return (rq->rq_flags & RQF_STARTED) && !blk_rq_is_passthrough(rq);
 671 }
 672 
 673 #define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)
 674 
 675 #define rq_data_dir(rq)         (op_is_write(req_op(rq)) ? WRITE : READ)
 676 
 677 #define rq_dma_dir(rq) \
 678         (op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
 679 
 680 #define dma_map_bvec(dev, bv, dir, attrs) \
 681         dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
 682         (dir), (attrs))
 683 
 684 static inline bool queue_is_mq(struct request_queue *q)
 685 {
 686         return q->mq_ops;
 687 }
 688 
 689 static inline enum blk_zoned_model
 690 blk_queue_zoned_model(struct request_queue *q)
 691 {
 692         return q->limits.zoned;
 693 }
 694 
 695 static inline bool blk_queue_is_zoned(struct request_queue *q)
 696 {
 697         switch (blk_queue_zoned_model(q)) {
 698         case BLK_ZONED_HA:
 699         case BLK_ZONED_HM:
 700                 return true;
 701         default:
 702                 return false;
 703         }
 704 }
 705 
 706 static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
 707 {
 708         return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
 709 }
 710 
 711 #ifdef CONFIG_BLK_DEV_ZONED
 712 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
 713 {
 714         return blk_queue_is_zoned(q) ? q->nr_zones : 0;
 715 }
 716 
 717 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
 718                                              sector_t sector)
 719 {
 720         if (!blk_queue_is_zoned(q))
 721                 return 0;
 722         return sector >> ilog2(q->limits.chunk_sectors);
 723 }
 724 
 725 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
 726                                          sector_t sector)
 727 {
 728         if (!blk_queue_is_zoned(q) || !q->seq_zones_bitmap)
 729                 return false;
 730         return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
 731 }
 732 #else /* CONFIG_BLK_DEV_ZONED */
 733 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
 734 {
 735         return 0;
 736 }
 737 #endif /* CONFIG_BLK_DEV_ZONED */
 738 
 739 static inline bool rq_is_sync(struct request *rq)
 740 {
 741         return op_is_sync(rq->cmd_flags);
 742 }
 743 
 744 static inline bool rq_mergeable(struct request *rq)
 745 {
 746         if (blk_rq_is_passthrough(rq))
 747                 return false;
 748 
 749         if (req_op(rq) == REQ_OP_FLUSH)
 750                 return false;
 751 
 752         if (req_op(rq) == REQ_OP_WRITE_ZEROES)
 753                 return false;
 754 
 755         if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
 756                 return false;
 757         if (rq->rq_flags & RQF_NOMERGE_FLAGS)
 758                 return false;
 759 
 760         return true;
 761 }
 762 
 763 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
 764 {
 765         if (bio_page(a) == bio_page(b) &&
 766             bio_offset(a) == bio_offset(b))
 767                 return true;
 768 
 769         return false;
 770 }
 771 
 772 static inline unsigned int blk_queue_depth(struct request_queue *q)
 773 {
 774         if (q->queue_depth)
 775                 return q->queue_depth;
 776 
 777         return q->nr_requests;
 778 }
 779 
 780 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 781 
 782 /*
 783  * standard bounce addresses:
 784  *
 785  * BLK_BOUNCE_HIGH      : bounce all highmem pages
 786  * BLK_BOUNCE_ANY       : don't bounce anything
 787  * BLK_BOUNCE_ISA       : bounce pages above ISA DMA boundary
 788  */
 789 
 790 #if BITS_PER_LONG == 32
 791 #define BLK_BOUNCE_HIGH         ((u64)blk_max_low_pfn << PAGE_SHIFT)
 792 #else
 793 #define BLK_BOUNCE_HIGH         -1ULL
 794 #endif
 795 #define BLK_BOUNCE_ANY          (-1ULL)
 796 #define BLK_BOUNCE_ISA          (DMA_BIT_MASK(24))
 797 
 798 /*
 799  * default timeout for SG_IO if none specified
 800  */
 801 #define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
 802 #define BLK_MIN_SG_TIMEOUT      (7 * HZ)
 803 
 804 struct rq_map_data {
 805         struct page **pages;
 806         int page_order;
 807         int nr_entries;
 808         unsigned long offset;
 809         int null_mapped;
 810         int from_user;
 811 };
 812 
 813 struct req_iterator {
 814         struct bvec_iter iter;
 815         struct bio *bio;
 816 };
 817 
 818 /* This should not be used directly - use rq_for_each_segment */
 819 #define for_each_bio(_bio)              \
 820         for (; _bio; _bio = _bio->bi_next)
 821 #define __rq_for_each_bio(_bio, rq)     \
 822         if ((rq->bio))                  \
 823                 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 824 
 825 #define rq_for_each_segment(bvl, _rq, _iter)                    \
 826         __rq_for_each_bio(_iter.bio, _rq)                       \
 827                 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
 828 
 829 #define rq_for_each_bvec(bvl, _rq, _iter)                       \
 830         __rq_for_each_bio(_iter.bio, _rq)                       \
 831                 bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
 832 
 833 #define rq_iter_last(bvec, _iter)                               \
 834                 (_iter.bio->bi_next == NULL &&                  \
 835                  bio_iter_last(bvec, _iter.iter))
 836 
 837 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 838 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 839 #endif
 840 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 841 extern void rq_flush_dcache_pages(struct request *rq);
 842 #else
 843 static inline void rq_flush_dcache_pages(struct request *rq)
 844 {
 845 }
 846 #endif
 847 
 848 extern int blk_register_queue(struct gendisk *disk);
 849 extern void blk_unregister_queue(struct gendisk *disk);
 850 extern blk_qc_t generic_make_request(struct bio *bio);
 851 extern blk_qc_t direct_make_request(struct bio *bio);
 852 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 853 extern void blk_put_request(struct request *);
 854 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
 855                                        blk_mq_req_flags_t flags);
 856 extern int blk_lld_busy(struct request_queue *q);
 857 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 858                              struct bio_set *bs, gfp_t gfp_mask,
 859                              int (*bio_ctr)(struct bio *, struct bio *, void *),
 860                              void *data);
 861 extern void blk_rq_unprep_clone(struct request *rq);
 862 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
 863                                      struct request *rq);
 864 extern int blk_rq_append_bio(struct request *rq, struct bio **bio);
 865 extern void blk_queue_split(struct request_queue *, struct bio **);
 866 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
 867 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
 868                               unsigned int, void __user *);
 869 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 870                           unsigned int, void __user *);
 871 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 872                          struct scsi_ioctl_command __user *);
 873 
 874 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
 875 extern void blk_queue_exit(struct request_queue *q);
 876 extern void blk_sync_queue(struct request_queue *q);
 877 extern int blk_rq_map_user(struct request_queue *, struct request *,
 878                            struct rq_map_data *, void __user *, unsigned long,
 879                            gfp_t);
 880 extern int blk_rq_unmap_user(struct bio *);
 881 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 882 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 883                                struct rq_map_data *, const struct iov_iter *,
 884                                gfp_t);
 885 extern void blk_execute_rq(struct request_queue *, struct gendisk *,
 886                           struct request *, int);
 887 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 888                                   struct request *, int, rq_end_io_fn *);
 889 
 890 /* Helper to convert REQ_OP_XXX to its string format XXX */
 891 extern const char *blk_op_str(unsigned int op);
 892 
 893 int blk_status_to_errno(blk_status_t status);
 894 blk_status_t errno_to_blk_status(int errno);
 895 
 896 int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin);
 897 
 898 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 899 {
 900         return bdev->bd_disk->queue;    /* this is never NULL */
 901 }
 902 
 903 /*
 904  * The basic unit of block I/O is a sector. It is used in a number of contexts
 905  * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
 906  * bytes. Variables of type sector_t represent an offset or size that is a
 907  * multiple of 512 bytes. Hence these two constants.
 908  */
 909 #ifndef SECTOR_SHIFT
 910 #define SECTOR_SHIFT 9
 911 #endif
 912 #ifndef SECTOR_SIZE
 913 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
 914 #endif
 915 
 916 /*
 917  * blk_rq_pos()                 : the current sector
 918  * blk_rq_bytes()               : bytes left in the entire request
 919  * blk_rq_cur_bytes()           : bytes left in the current segment
 920  * blk_rq_err_bytes()           : bytes left till the next error boundary
 921  * blk_rq_sectors()             : sectors left in the entire request
 922  * blk_rq_cur_sectors()         : sectors left in the current segment
 923  * blk_rq_stats_sectors()       : sectors of the entire request used for stats
 924  */
 925 static inline sector_t blk_rq_pos(const struct request *rq)
 926 {
 927         return rq->__sector;
 928 }
 929 
 930 static inline unsigned int blk_rq_bytes(const struct request *rq)
 931 {
 932         return rq->__data_len;
 933 }
 934 
 935 static inline int blk_rq_cur_bytes(const struct request *rq)
 936 {
 937         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 938 }
 939 
 940 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 941 
 942 static inline unsigned int blk_rq_sectors(const struct request *rq)
 943 {
 944         return blk_rq_bytes(rq) >> SECTOR_SHIFT;
 945 }
 946 
 947 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 948 {
 949         return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
 950 }
 951 
 952 static inline unsigned int blk_rq_stats_sectors(const struct request *rq)
 953 {
 954         return rq->stats_sectors;
 955 }
 956 
 957 #ifdef CONFIG_BLK_DEV_ZONED
 958 static inline unsigned int blk_rq_zone_no(struct request *rq)
 959 {
 960         return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
 961 }
 962 
 963 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
 964 {
 965         return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
 966 }
 967 #endif /* CONFIG_BLK_DEV_ZONED */
 968 
 969 /*
 970  * Some commands like WRITE SAME have a payload or data transfer size which
 971  * is different from the size of the request.  Any driver that supports such
 972  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
 973  * calculate the data transfer size.
 974  */
 975 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
 976 {
 977         if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
 978                 return rq->special_vec.bv_len;
 979         return blk_rq_bytes(rq);
 980 }
 981 
 982 /*
 983  * Return the first full biovec in the request.  The caller needs to check that
 984  * there are any bvecs before calling this helper.
 985  */
 986 static inline struct bio_vec req_bvec(struct request *rq)
 987 {
 988         if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
 989                 return rq->special_vec;
 990         return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
 991 }
 992 
 993 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
 994                                                      int op)
 995 {
 996         if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
 997                 return min(q->limits.max_discard_sectors,
 998                            UINT_MAX >> SECTOR_SHIFT);
 999 
1000         if (unlikely(op == REQ_OP_WRITE_SAME))
1001                 return q->limits.max_write_same_sectors;
1002 
1003         if (unlikely(op == REQ_OP_WRITE_ZEROES))
1004                 return q->limits.max_write_zeroes_sectors;
1005 
1006         return q->limits.max_sectors;
1007 }
1008 
1009 /*
1010  * Return maximum size of a request at given offset. Only valid for
1011  * file system requests.
1012  */
1013 static inline unsigned int blk_max_size_offset(struct request_queue *q,
1014                                                sector_t offset)
1015 {
1016         if (!q->limits.chunk_sectors)
1017                 return q->limits.max_sectors;
1018 
1019         return min(q->limits.max_sectors, (unsigned int)(q->limits.chunk_sectors -
1020                         (offset & (q->limits.chunk_sectors - 1))));
1021 }
1022 
1023 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
1024                                                   sector_t offset)
1025 {
1026         struct request_queue *q = rq->q;
1027 
1028         if (blk_rq_is_passthrough(rq))
1029                 return q->limits.max_hw_sectors;
1030 
1031         if (!q->limits.chunk_sectors ||
1032             req_op(rq) == REQ_OP_DISCARD ||
1033             req_op(rq) == REQ_OP_SECURE_ERASE)
1034                 return blk_queue_get_max_sectors(q, req_op(rq));
1035 
1036         return min(blk_max_size_offset(q, offset),
1037                         blk_queue_get_max_sectors(q, req_op(rq)));
1038 }
1039 
1040 static inline unsigned int blk_rq_count_bios(struct request *rq)
1041 {
1042         unsigned int nr_bios = 0;
1043         struct bio *bio;
1044 
1045         __rq_for_each_bio(bio, rq)
1046                 nr_bios++;
1047 
1048         return nr_bios;
1049 }
1050 
1051 void blk_steal_bios(struct bio_list *list, struct request *rq);
1052 
1053 /*
1054  * Request completion related functions.
1055  *
1056  * blk_update_request() completes given number of bytes and updates
1057  * the request without completing it.
1058  */
1059 extern bool blk_update_request(struct request *rq, blk_status_t error,
1060                                unsigned int nr_bytes);
1061 
1062 extern void __blk_complete_request(struct request *);
1063 extern void blk_abort_request(struct request *);
1064 
1065 /*
1066  * Access functions for manipulating queue properties
1067  */
1068 extern void blk_cleanup_queue(struct request_queue *);
1069 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1070 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1071 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1072 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1073 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1074 extern void blk_queue_max_discard_segments(struct request_queue *,
1075                 unsigned short);
1076 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1077 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1078                 unsigned int max_discard_sectors);
1079 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1080                 unsigned int max_write_same_sectors);
1081 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1082                 unsigned int max_write_same_sectors);
1083 extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
1084 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1085 extern void blk_queue_alignment_offset(struct request_queue *q,
1086                                        unsigned int alignment);
1087 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1088 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1089 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1090 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1091 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1092 extern void blk_set_default_limits(struct queue_limits *lim);
1093 extern void blk_set_stacking_limits(struct queue_limits *lim);
1094 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1095                             sector_t offset);
1096 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1097                             sector_t offset);
1098 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1099                               sector_t offset);
1100 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1101 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1102 extern int blk_queue_dma_drain(struct request_queue *q,
1103                                dma_drain_needed_fn *dma_drain_needed,
1104                                void *buf, unsigned int size);
1105 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1106 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1107 extern void blk_queue_dma_alignment(struct request_queue *, int);
1108 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1109 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1110 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1111 extern void blk_queue_required_elevator_features(struct request_queue *q,
1112                                                  unsigned int features);
1113 extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
1114                                               struct device *dev);
1115 
1116 /*
1117  * Number of physical segments as sent to the device.
1118  *
1119  * Normally this is the number of discontiguous data segments sent by the
1120  * submitter.  But for data-less command like discard we might have no
1121  * actual data segments submitted, but the driver might have to add it's
1122  * own special payload.  In that case we still return 1 here so that this
1123  * special payload will be mapped.
1124  */
1125 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1126 {
1127         if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1128                 return 1;
1129         return rq->nr_phys_segments;
1130 }
1131 
1132 /*
1133  * Number of discard segments (or ranges) the driver needs to fill in.
1134  * Each discard bio merged into a request is counted as one segment.
1135  */
1136 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1137 {
1138         return max_t(unsigned short, rq->nr_phys_segments, 1);
1139 }
1140 
1141 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1142 extern void blk_dump_rq_flags(struct request *, char *);
1143 extern long nr_blockdev_pages(void);
1144 
1145 bool __must_check blk_get_queue(struct request_queue *);
1146 struct request_queue *blk_alloc_queue(gfp_t);
1147 struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id);
1148 extern void blk_put_queue(struct request_queue *);
1149 extern void blk_set_queue_dying(struct request_queue *);
1150 
1151 /*
1152  * blk_plug permits building a queue of related requests by holding the I/O
1153  * fragments for a short period. This allows merging of sequential requests
1154  * into single larger request. As the requests are moved from a per-task list to
1155  * the device's request_queue in a batch, this results in improved scalability
1156  * as the lock contention for request_queue lock is reduced.
1157  *
1158  * It is ok not to disable preemption when adding the request to the plug list
1159  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1160  * the plug list when the task sleeps by itself. For details, please see
1161  * schedule() where blk_schedule_flush_plug() is called.
1162  */
1163 struct blk_plug {
1164         struct list_head mq_list; /* blk-mq requests */
1165         struct list_head cb_list; /* md requires an unplug callback */
1166         unsigned short rq_count;
1167         bool multiple_queues;
1168 };
1169 #define BLK_MAX_REQUEST_COUNT 16
1170 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1171 
1172 struct blk_plug_cb;
1173 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1174 struct blk_plug_cb {
1175         struct list_head list;
1176         blk_plug_cb_fn callback;
1177         void *data;
1178 };
1179 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1180                                              void *data, int size);
1181 extern void blk_start_plug(struct blk_plug *);
1182 extern void blk_finish_plug(struct blk_plug *);
1183 extern void blk_flush_plug_list(struct blk_plug *, bool);
1184 
1185 static inline void blk_flush_plug(struct task_struct *tsk)
1186 {
1187         struct blk_plug *plug = tsk->plug;
1188 
1189         if (plug)
1190                 blk_flush_plug_list(plug, false);
1191 }
1192 
1193 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1194 {
1195         struct blk_plug *plug = tsk->plug;
1196 
1197         if (plug)
1198                 blk_flush_plug_list(plug, true);
1199 }
1200 
1201 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1202 {
1203         struct blk_plug *plug = tsk->plug;
1204 
1205         return plug &&
1206                  (!list_empty(&plug->mq_list) ||
1207                  !list_empty(&plug->cb_list));
1208 }
1209 
1210 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1211 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1212                 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1213 
1214 #define BLKDEV_DISCARD_SECURE   (1 << 0)        /* issue a secure erase */
1215 
1216 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1217                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1218 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1219                 sector_t nr_sects, gfp_t gfp_mask, int flags,
1220                 struct bio **biop);
1221 
1222 #define BLKDEV_ZERO_NOUNMAP     (1 << 0)  /* do not free blocks */
1223 #define BLKDEV_ZERO_NOFALLBACK  (1 << 1)  /* don't write explicit zeroes */
1224 
1225 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1226                 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1227                 unsigned flags);
1228 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1229                 sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1230 
1231 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1232                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1233 {
1234         return blkdev_issue_discard(sb->s_bdev,
1235                                     block << (sb->s_blocksize_bits -
1236                                               SECTOR_SHIFT),
1237                                     nr_blocks << (sb->s_blocksize_bits -
1238                                                   SECTOR_SHIFT),
1239                                     gfp_mask, flags);
1240 }
1241 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1242                 sector_t nr_blocks, gfp_t gfp_mask)
1243 {
1244         return blkdev_issue_zeroout(sb->s_bdev,
1245                                     block << (sb->s_blocksize_bits -
1246                                               SECTOR_SHIFT),
1247                                     nr_blocks << (sb->s_blocksize_bits -
1248                                                   SECTOR_SHIFT),
1249                                     gfp_mask, 0);
1250 }
1251 
1252 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1253 
1254 enum blk_default_limits {
1255         BLK_MAX_SEGMENTS        = 128,
1256         BLK_SAFE_MAX_SECTORS    = 255,
1257         BLK_DEF_MAX_SECTORS     = 2560,
1258         BLK_MAX_SEGMENT_SIZE    = 65536,
1259         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
1260 };
1261 
1262 static inline unsigned long queue_segment_boundary(const struct request_queue *q)
1263 {
1264         return q->limits.seg_boundary_mask;
1265 }
1266 
1267 static inline unsigned long queue_virt_boundary(const struct request_queue *q)
1268 {
1269         return q->limits.virt_boundary_mask;
1270 }
1271 
1272 static inline unsigned int queue_max_sectors(const struct request_queue *q)
1273 {
1274         return q->limits.max_sectors;
1275 }
1276 
1277 static inline unsigned int queue_max_hw_sectors(const struct request_queue *q)
1278 {
1279         return q->limits.max_hw_sectors;
1280 }
1281 
1282 static inline unsigned short queue_max_segments(const struct request_queue *q)
1283 {
1284         return q->limits.max_segments;
1285 }
1286 
1287 static inline unsigned short queue_max_discard_segments(const struct request_queue *q)
1288 {
1289         return q->limits.max_discard_segments;
1290 }
1291 
1292 static inline unsigned int queue_max_segment_size(const struct request_queue *q)
1293 {
1294         return q->limits.max_segment_size;
1295 }
1296 
1297 static inline unsigned queue_logical_block_size(const struct request_queue *q)
1298 {
1299         int retval = 512;
1300 
1301         if (q && q->limits.logical_block_size)
1302                 retval = q->limits.logical_block_size;
1303 
1304         return retval;
1305 }
1306 
1307 static inline unsigned int bdev_logical_block_size(struct block_device *bdev)
1308 {
1309         return queue_logical_block_size(bdev_get_queue(bdev));
1310 }
1311 
1312 static inline unsigned int queue_physical_block_size(const struct request_queue *q)
1313 {
1314         return q->limits.physical_block_size;
1315 }
1316 
1317 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1318 {
1319         return queue_physical_block_size(bdev_get_queue(bdev));
1320 }
1321 
1322 static inline unsigned int queue_io_min(const struct request_queue *q)
1323 {
1324         return q->limits.io_min;
1325 }
1326 
1327 static inline int bdev_io_min(struct block_device *bdev)
1328 {
1329         return queue_io_min(bdev_get_queue(bdev));
1330 }
1331 
1332 static inline unsigned int queue_io_opt(const struct request_queue *q)
1333 {
1334         return q->limits.io_opt;
1335 }
1336 
1337 static inline int bdev_io_opt(struct block_device *bdev)
1338 {
1339         return queue_io_opt(bdev_get_queue(bdev));
1340 }
1341 
1342 static inline int queue_alignment_offset(const struct request_queue *q)
1343 {
1344         if (q->limits.misaligned)
1345                 return -1;
1346 
1347         return q->limits.alignment_offset;
1348 }
1349 
1350 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1351 {
1352         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1353         unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1354                 << SECTOR_SHIFT;
1355 
1356         return (granularity + lim->alignment_offset - alignment) % granularity;
1357 }
1358 
1359 static inline int bdev_alignment_offset(struct block_device *bdev)
1360 {
1361         struct request_queue *q = bdev_get_queue(bdev);
1362 
1363         if (q->limits.misaligned)
1364                 return -1;
1365 
1366         if (bdev != bdev->bd_contains)
1367                 return bdev->bd_part->alignment_offset;
1368 
1369         return q->limits.alignment_offset;
1370 }
1371 
1372 static inline int queue_discard_alignment(const struct request_queue *q)
1373 {
1374         if (q->limits.discard_misaligned)
1375                 return -1;
1376 
1377         return q->limits.discard_alignment;
1378 }
1379 
1380 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1381 {
1382         unsigned int alignment, granularity, offset;
1383 
1384         if (!lim->max_discard_sectors)
1385                 return 0;
1386 
1387         /* Why are these in bytes, not sectors? */
1388         alignment = lim->discard_alignment >> SECTOR_SHIFT;
1389         granularity = lim->discard_granularity >> SECTOR_SHIFT;
1390         if (!granularity)
1391                 return 0;
1392 
1393         /* Offset of the partition start in 'granularity' sectors */
1394         offset = sector_div(sector, granularity);
1395 
1396         /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1397         offset = (granularity + alignment - offset) % granularity;
1398 
1399         /* Turn it back into bytes, gaah */
1400         return offset << SECTOR_SHIFT;
1401 }
1402 
1403 static inline int bdev_discard_alignment(struct block_device *bdev)
1404 {
1405         struct request_queue *q = bdev_get_queue(bdev);
1406 
1407         if (bdev != bdev->bd_contains)
1408                 return bdev->bd_part->discard_alignment;
1409 
1410         return q->limits.discard_alignment;
1411 }
1412 
1413 static inline unsigned int bdev_write_same(struct block_device *bdev)
1414 {
1415         struct request_queue *q = bdev_get_queue(bdev);
1416 
1417         if (q)
1418                 return q->limits.max_write_same_sectors;
1419 
1420         return 0;
1421 }
1422 
1423 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1424 {
1425         struct request_queue *q = bdev_get_queue(bdev);
1426 
1427         if (q)
1428                 return q->limits.max_write_zeroes_sectors;
1429 
1430         return 0;
1431 }
1432 
1433 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1434 {
1435         struct request_queue *q = bdev_get_queue(bdev);
1436 
1437         if (q)
1438                 return blk_queue_zoned_model(q);
1439 
1440         return BLK_ZONED_NONE;
1441 }
1442 
1443 static inline bool bdev_is_zoned(struct block_device *bdev)
1444 {
1445         struct request_queue *q = bdev_get_queue(bdev);
1446 
1447         if (q)
1448                 return blk_queue_is_zoned(q);
1449 
1450         return false;
1451 }
1452 
1453 static inline sector_t bdev_zone_sectors(struct block_device *bdev)
1454 {
1455         struct request_queue *q = bdev_get_queue(bdev);
1456 
1457         if (q)
1458                 return blk_queue_zone_sectors(q);
1459         return 0;
1460 }
1461 
1462 static inline int queue_dma_alignment(const struct request_queue *q)
1463 {
1464         return q ? q->dma_alignment : 511;
1465 }
1466 
1467 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1468                                  unsigned int len)
1469 {
1470         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1471         return !(addr & alignment) && !(len & alignment);
1472 }
1473 
1474 /* assumes size > 256 */
1475 static inline unsigned int blksize_bits(unsigned int size)
1476 {
1477         unsigned int bits = 8;
1478         do {
1479                 bits++;
1480                 size >>= 1;
1481         } while (size > 256);
1482         return bits;
1483 }
1484 
1485 static inline unsigned int block_size(struct block_device *bdev)
1486 {
1487         return bdev->bd_block_size;
1488 }
1489 
1490 typedef struct {struct page *v;} Sector;
1491 
1492 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1493 
1494 static inline void put_dev_sector(Sector p)
1495 {
1496         put_page(p.v);
1497 }
1498 
1499 int kblockd_schedule_work(struct work_struct *work);
1500 int kblockd_schedule_work_on(int cpu, struct work_struct *work);
1501 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1502 
1503 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1504         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1505 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1506         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1507 
1508 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1509 
1510 enum blk_integrity_flags {
1511         BLK_INTEGRITY_VERIFY            = 1 << 0,
1512         BLK_INTEGRITY_GENERATE          = 1 << 1,
1513         BLK_INTEGRITY_DEVICE_CAPABLE    = 1 << 2,
1514         BLK_INTEGRITY_IP_CHECKSUM       = 1 << 3,
1515 };
1516 
1517 struct blk_integrity_iter {
1518         void                    *prot_buf;
1519         void                    *data_buf;
1520         sector_t                seed;
1521         unsigned int            data_size;
1522         unsigned short          interval;
1523         const char              *disk_name;
1524 };
1525 
1526 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1527 typedef void (integrity_prepare_fn) (struct request *);
1528 typedef void (integrity_complete_fn) (struct request *, unsigned int);
1529 
1530 struct blk_integrity_profile {
1531         integrity_processing_fn         *generate_fn;
1532         integrity_processing_fn         *verify_fn;
1533         integrity_prepare_fn            *prepare_fn;
1534         integrity_complete_fn           *complete_fn;
1535         const char                      *name;
1536 };
1537 
1538 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1539 extern void blk_integrity_unregister(struct gendisk *);
1540 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1541 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1542                                    struct scatterlist *);
1543 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1544 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1545                                    struct request *);
1546 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1547                                     struct bio *);
1548 
1549 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1550 {
1551         struct blk_integrity *bi = &disk->queue->integrity;
1552 
1553         if (!bi->profile)
1554                 return NULL;
1555 
1556         return bi;
1557 }
1558 
1559 static inline
1560 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1561 {
1562         return blk_get_integrity(bdev->bd_disk);
1563 }
1564 
1565 static inline bool blk_integrity_rq(struct request *rq)
1566 {
1567         return rq->cmd_flags & REQ_INTEGRITY;
1568 }
1569 
1570 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1571                                                     unsigned int segs)
1572 {
1573         q->limits.max_integrity_segments = segs;
1574 }
1575 
1576 static inline unsigned short
1577 queue_max_integrity_segments(const struct request_queue *q)
1578 {
1579         return q->limits.max_integrity_segments;
1580 }
1581 
1582 /**
1583  * bio_integrity_intervals - Return number of integrity intervals for a bio
1584  * @bi:         blk_integrity profile for device
1585  * @sectors:    Size of the bio in 512-byte sectors
1586  *
1587  * Description: The block layer calculates everything in 512 byte
1588  * sectors but integrity metadata is done in terms of the data integrity
1589  * interval size of the storage device.  Convert the block layer sectors
1590  * to the appropriate number of integrity intervals.
1591  */
1592 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1593                                                    unsigned int sectors)
1594 {
1595         return sectors >> (bi->interval_exp - 9);
1596 }
1597 
1598 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1599                                                unsigned int sectors)
1600 {
1601         return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
1602 }
1603 
1604 /*
1605  * Return the first bvec that contains integrity data.  Only drivers that are
1606  * limited to a single integrity segment should use this helper.
1607  */
1608 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1609 {
1610         if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
1611                 return NULL;
1612         return rq->bio->bi_integrity->bip_vec;
1613 }
1614 
1615 #else /* CONFIG_BLK_DEV_INTEGRITY */
1616 
1617 struct bio;
1618 struct block_device;
1619 struct gendisk;
1620 struct blk_integrity;
1621 
1622 static inline int blk_integrity_rq(struct request *rq)
1623 {
1624         return 0;
1625 }
1626 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1627                                             struct bio *b)
1628 {
1629         return 0;
1630 }
1631 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1632                                           struct bio *b,
1633                                           struct scatterlist *s)
1634 {
1635         return 0;
1636 }
1637 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1638 {
1639         return NULL;
1640 }
1641 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1642 {
1643         return NULL;
1644 }
1645 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1646 {
1647         return 0;
1648 }
1649 static inline void blk_integrity_register(struct gendisk *d,
1650                                          struct blk_integrity *b)
1651 {
1652 }
1653 static inline void blk_integrity_unregister(struct gendisk *d)
1654 {
1655 }
1656 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1657                                                     unsigned int segs)
1658 {
1659 }
1660 static inline unsigned short queue_max_integrity_segments(const struct request_queue *q)
1661 {
1662         return 0;
1663 }
1664 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1665                                           struct request *r1,
1666                                           struct request *r2)
1667 {
1668         return true;
1669 }
1670 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1671                                            struct request *r,
1672                                            struct bio *b)
1673 {
1674         return true;
1675 }
1676 
1677 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1678                                                    unsigned int sectors)
1679 {
1680         return 0;
1681 }
1682 
1683 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1684                                                unsigned int sectors)
1685 {
1686         return 0;
1687 }
1688 
1689 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1690 {
1691         return NULL;
1692 }
1693 
1694 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1695 
1696 struct block_device_operations {
1697         int (*open) (struct block_device *, fmode_t);
1698         void (*release) (struct gendisk *, fmode_t);
1699         int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
1700         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1701         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1702         unsigned int (*check_events) (struct gendisk *disk,
1703                                       unsigned int clearing);
1704         /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1705         int (*media_changed) (struct gendisk *);
1706         void (*unlock_native_capacity) (struct gendisk *);
1707         int (*revalidate_disk) (struct gendisk *);
1708         int (*getgeo)(struct block_device *, struct hd_geometry *);
1709         /* this callback is with swap_lock and sometimes page table lock held */
1710         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1711         int (*report_zones)(struct gendisk *, sector_t sector,
1712                             struct blk_zone *zones, unsigned int *nr_zones);
1713         struct module *owner;
1714         const struct pr_ops *pr_ops;
1715 };
1716 
1717 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1718                                  unsigned long);
1719 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1720 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1721                                                 struct writeback_control *);
1722 
1723 #ifdef CONFIG_BLK_DEV_ZONED
1724 bool blk_req_needs_zone_write_lock(struct request *rq);
1725 void __blk_req_zone_write_lock(struct request *rq);
1726 void __blk_req_zone_write_unlock(struct request *rq);
1727 
1728 static inline void blk_req_zone_write_lock(struct request *rq)
1729 {
1730         if (blk_req_needs_zone_write_lock(rq))
1731                 __blk_req_zone_write_lock(rq);
1732 }
1733 
1734 static inline void blk_req_zone_write_unlock(struct request *rq)
1735 {
1736         if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
1737                 __blk_req_zone_write_unlock(rq);
1738 }
1739 
1740 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1741 {
1742         return rq->q->seq_zones_wlock &&
1743                 test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
1744 }
1745 
1746 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1747 {
1748         if (!blk_req_needs_zone_write_lock(rq))
1749                 return true;
1750         return !blk_req_zone_is_write_locked(rq);
1751 }
1752 #else
1753 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
1754 {
1755         return false;
1756 }
1757 
1758 static inline void blk_req_zone_write_lock(struct request *rq)
1759 {
1760 }
1761 
1762 static inline void blk_req_zone_write_unlock(struct request *rq)
1763 {
1764 }
1765 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1766 {
1767         return false;
1768 }
1769 
1770 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1771 {
1772         return true;
1773 }
1774 #endif /* CONFIG_BLK_DEV_ZONED */
1775 
1776 #else /* CONFIG_BLOCK */
1777 
1778 struct block_device;
1779 
1780 /*
1781  * stubs for when the block layer is configured out
1782  */
1783 #define buffer_heads_over_limit 0
1784 
1785 static inline long nr_blockdev_pages(void)
1786 {
1787         return 0;
1788 }
1789 
1790 struct blk_plug {
1791 };
1792 
1793 static inline void blk_start_plug(struct blk_plug *plug)
1794 {
1795 }
1796 
1797 static inline void blk_finish_plug(struct blk_plug *plug)
1798 {
1799 }
1800 
1801 static inline void blk_flush_plug(struct task_struct *task)
1802 {
1803 }
1804 
1805 static inline void blk_schedule_flush_plug(struct task_struct *task)
1806 {
1807 }
1808 
1809 
1810 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1811 {
1812         return false;
1813 }
1814 
1815 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1816                                      sector_t *error_sector)
1817 {
1818         return 0;
1819 }
1820 
1821 #endif /* CONFIG_BLOCK */
1822 
1823 static inline void blk_wake_io_task(struct task_struct *waiter)
1824 {
1825         /*
1826          * If we're polling, the task itself is doing the completions. For
1827          * that case, we don't need to signal a wakeup, it's enough to just
1828          * mark us as RUNNING.
1829          */
1830         if (waiter == current)
1831                 __set_current_state(TASK_RUNNING);
1832         else
1833                 wake_up_process(waiter);
1834 }
1835 
1836 #endif
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root/include/linux/blkdev.h

INCLUDED FROM

DEFINITIONS
