block/blk.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef BLK_INTERNAL_H
   3 #define BLK_INTERNAL_H
   4
   5 #include <linux/idr.h>
   6 #include <linux/blk-mq.h>
   7 #include <xen/xen.h>
   8 #include "blk-mq.h"
   9 #include "blk-mq-sched.h"
  10
  11 /* Max future timer expiry for timeouts */
  12 #define BLK_MAX_TIMEOUT         (5 * HZ)
  13
  14 #ifdef CONFIG_DEBUG_FS
  15 extern struct dentry *blk_debugfs_root;
  16 #endif
  17
  18 struct blk_flush_queue {
  19         unsigned int            flush_queue_delayed:1;
  20         unsigned int            flush_pending_idx:1;
  21         unsigned int            flush_running_idx:1;
  22         blk_status_t            rq_status;
  23         unsigned long           flush_pending_since;
  24         struct list_head        flush_queue[2];
  25         struct list_head        flush_data_in_flight;
  26         struct request          *flush_rq;
  27
  28         /*
  29          * flush_rq shares tag with this rq, both can't be active
  30          * at the same time
  31          */
  32         struct request          *orig_rq;
  33         struct lock_class_key   key;
  34         spinlock_t              mq_flush_lock;
  35 };
  36
  37 extern struct kmem_cache *blk_requestq_cachep;
  38 extern struct kobj_type blk_queue_ktype;
  39 extern struct ida blk_queue_ida;
  40
  41 static inline struct blk_flush_queue *
  42 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
  43 {
  44         return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
  45 }
  46
  47 static inline void __blk_get_queue(struct request_queue *q)
  48 {
  49         kobject_get(&q->kobj);
  50 }
  51
  52 static inline bool
  53 is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
  54 {
  55         return hctx->fq->flush_rq == req;
  56 }
  57
  58 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
  59                                               gfp_t flags);
  60 void blk_free_flush_queue(struct blk_flush_queue *q);
  61
  62 void blk_freeze_queue(struct request_queue *q);
  63
  64 static inline void blk_queue_enter_live(struct request_queue *q)
  65 {
  66         /*
  67          * Given that running in generic_make_request() context
  68          * guarantees that a live reference against q_usage_counter has
  69          * been established, further references under that same context
  70          * need not check that the queue has been frozen (marked dead).
  71          */
  72         percpu_ref_get(&q->q_usage_counter);
  73 }
  74
  75 static inline bool biovec_phys_mergeable(struct request_queue *q,
  76                 struct bio_vec *vec1, struct bio_vec *vec2)
  77 {
  78         unsigned long mask = queue_segment_boundary(q);
  79         phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
  80         phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
  81
  82         if (addr1 + vec1->bv_len != addr2)
  83                 return false;
  84         if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
  85                 return false;
  86         if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
  87                 return false;
  88         return true;
  89 }
  90
  91 static inline bool __bvec_gap_to_prev(struct request_queue *q,
  92                 struct bio_vec *bprv, unsigned int offset)
  93 {
  94         return (offset & queue_virt_boundary(q)) ||
  95                 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
  96 }
  97
  98 /*
  99  * Check if adding a bio_vec after bprv with offset would create a gap in
 100  * the SG list. Most drivers don't care about this, but some do.
 101  */
 102 static inline bool bvec_gap_to_prev(struct request_queue *q,
 103                 struct bio_vec *bprv, unsigned int offset)
 104 {
 105         if (!queue_virt_boundary(q))
 106                 return false;
 107         return __bvec_gap_to_prev(q, bprv, offset);
 108 }
 109
 110 static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
 111                 unsigned int nr_segs)
 112 {
 113         rq->nr_phys_segments = nr_segs;
 114         rq->__data_len = bio->bi_iter.bi_size;
 115         rq->bio = rq->biotail = bio;
 116         rq->ioprio = bio_prio(bio);
 117
 118         if (bio->bi_disk)
 119                 rq->rq_disk = bio->bi_disk;
 120 }
 121
 122 #ifdef CONFIG_BLK_DEV_INTEGRITY
 123 void blk_flush_integrity(void);
 124 bool __bio_integrity_endio(struct bio *);
 125 void bio_integrity_free(struct bio *bio);
 126 static inline bool bio_integrity_endio(struct bio *bio)
 127 {
 128         if (bio_integrity(bio))
 129                 return __bio_integrity_endio(bio);
 130         return true;
 131 }
 132
 133 static inline bool integrity_req_gap_back_merge(struct request *req,
 134                 struct bio *next)
 135 {
 136         struct bio_integrity_payload *bip = bio_integrity(req->bio);
 137         struct bio_integrity_payload *bip_next = bio_integrity(next);
 138
 139         return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
 140                                 bip_next->bip_vec[0].bv_offset);
 141 }
 142
 143 static inline bool integrity_req_gap_front_merge(struct request *req,
 144                 struct bio *bio)
 145 {
 146         struct bio_integrity_payload *bip = bio_integrity(bio);
 147         struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
 148
 149         return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
 150                                 bip_next->bip_vec[0].bv_offset);
 151 }
 152 #else /* CONFIG_BLK_DEV_INTEGRITY */
 153 static inline bool integrity_req_gap_back_merge(struct request *req,
 154                 struct bio *next)
 155 {
 156         return false;
 157 }
 158 static inline bool integrity_req_gap_front_merge(struct request *req,
 159                 struct bio *bio)
 160 {
 161         return false;
 162 }
 163
 164 static inline void blk_flush_integrity(void)
 165 {
 166 }
 167 static inline bool bio_integrity_endio(struct bio *bio)
 168 {
 169         return true;
 170 }
 171 static inline void bio_integrity_free(struct bio *bio)
 172 {
 173 }
 174 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 175
 176 unsigned long blk_rq_timeout(unsigned long timeout);
 177 void blk_add_timer(struct request *req);
 178
 179 bool bio_attempt_front_merge(struct request *req, struct bio *bio,
 180                 unsigned int nr_segs);
 181 bool bio_attempt_back_merge(struct request *req, struct bio *bio,
 182                 unsigned int nr_segs);
 183 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
 184                 struct bio *bio);
 185 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 186                 unsigned int nr_segs, struct request **same_queue_rq);
 187
 188 void blk_account_io_start(struct request *req, bool new_io);
 189 void blk_account_io_completion(struct request *req, unsigned int bytes);
 190 void blk_account_io_done(struct request *req, u64 now);
 191
 192 /*
 193  * Internal elevator interface
 194  */
 195 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
 196
 197 void blk_insert_flush(struct request *rq);
 198
 199 void elevator_init_mq(struct request_queue *q);
 200 int elevator_switch_mq(struct request_queue *q,
 201                               struct elevator_type *new_e);
 202 void __elevator_exit(struct request_queue *, struct elevator_queue *);
 203 int elv_register_queue(struct request_queue *q, bool uevent);
 204 void elv_unregister_queue(struct request_queue *q);
 205
 206 static inline void elevator_exit(struct request_queue *q,
 207                 struct elevator_queue *e)
 208 {
 209         lockdep_assert_held(&q->sysfs_lock);
 210
 211         blk_mq_sched_free_requests(q);
 212         __elevator_exit(q, e);
 213 }
 214
 215 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 216
 217 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
 218                 char *buf);
 219 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
 220                 char *buf);
 221 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
 222                 char *buf);
 223 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
 224                 char *buf);
 225 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
 226                 const char *buf, size_t count);
 227
 228 #ifdef CONFIG_FAIL_IO_TIMEOUT
 229 int blk_should_fake_timeout(struct request_queue *);
 230 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
 231 ssize_t part_timeout_store(struct device *, struct device_attribute *,
 232                                 const char *, size_t);
 233 #else
 234 static inline int blk_should_fake_timeout(struct request_queue *q)
 235 {
 236         return 0;
 237 }
 238 #endif
 239
 240 void __blk_queue_split(struct request_queue *q, struct bio **bio,
 241                 unsigned int *nr_segs);
 242 int ll_back_merge_fn(struct request *req, struct bio *bio,
 243                 unsigned int nr_segs);
 244 int ll_front_merge_fn(struct request *req,  struct bio *bio,
 245                 unsigned int nr_segs);
 246 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
 247 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
 248 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
 249                                 struct request *next);
 250 unsigned int blk_recalc_rq_segments(struct request *rq);
 251 void blk_rq_set_mixed_merge(struct request *rq);
 252 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
 253 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
 254
 255 int blk_dev_init(void);
 256
 257 /*
 258  * Contribute to IO statistics IFF:
 259  *
 260  *      a) it's attached to a gendisk, and
 261  *      b) the queue had IO stats enabled when this request was started
 262  */
 263 static inline bool blk_do_io_stat(struct request *rq)
 264 {
 265         return rq->rq_disk && (rq->rq_flags & RQF_IO_STAT);
 266 }
 267
 268 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
 269 {
 270         req->cmd_flags |= REQ_NOMERGE;
 271         if (req == q->last_merge)
 272                 q->last_merge = NULL;
 273 }
 274
 275 /*
 276  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
 277  * is defined as 'unsigned int', meantime it has to aligned to with logical
 278  * block size which is the minimum accepted unit by hardware.
 279  */
 280 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
 281 {
 282         return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
 283 }
 284
 285 /*
 286  * Internal io_context interface
 287  */
 288 void get_io_context(struct io_context *ioc);
 289 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
 290 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
 291                              gfp_t gfp_mask);
 292 void ioc_clear_queue(struct request_queue *q);
 293
 294 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
 295
 296 /**
 297  * create_io_context - try to create task->io_context
 298  * @gfp_mask: allocation mask
 299  * @node: allocation node
 300  *
 301  * If %current->io_context is %NULL, allocate a new io_context and install
 302  * it.  Returns the current %current->io_context which may be %NULL if
 303  * allocation failed.
 304  *
 305  * Note that this function can't be called with IRQ disabled because
 306  * task_lock which protects %current->io_context is IRQ-unsafe.
 307  */
 308 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
 309 {
 310         WARN_ON_ONCE(irqs_disabled());
 311         if (unlikely(!current->io_context))
 312                 create_task_io_context(current, gfp_mask, node);
 313         return current->io_context;
 314 }
 315
 316 /*
 317  * Internal throttling interface
 318  */
 319 #ifdef CONFIG_BLK_DEV_THROTTLING
 320 extern void blk_throtl_drain(struct request_queue *q);
 321 extern int blk_throtl_init(struct request_queue *q);
 322 extern void blk_throtl_exit(struct request_queue *q);
 323 extern void blk_throtl_register_queue(struct request_queue *q);
 324 #else /* CONFIG_BLK_DEV_THROTTLING */
 325 static inline void blk_throtl_drain(struct request_queue *q) { }
 326 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
 327 static inline void blk_throtl_exit(struct request_queue *q) { }
 328 static inline void blk_throtl_register_queue(struct request_queue *q) { }
 329 #endif /* CONFIG_BLK_DEV_THROTTLING */
 330 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 331 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
 332 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
 333         const char *page, size_t count);
 334 extern void blk_throtl_bio_endio(struct bio *bio);
 335 extern void blk_throtl_stat_add(struct request *rq, u64 time);
 336 #else
 337 static inline void blk_throtl_bio_endio(struct bio *bio) { }
 338 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
 339 #endif
 340
 341 #ifdef CONFIG_BOUNCE
 342 extern int init_emergency_isa_pool(void);
 343 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 344 #else
 345 static inline int init_emergency_isa_pool(void)
 346 {
 347         return 0;
 348 }
 349 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 350 {
 351 }
 352 #endif /* CONFIG_BOUNCE */
 353
 354 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
 355 extern int blk_iolatency_init(struct request_queue *q);
 356 #else
 357 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
 358 #endif
 359
 360 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
 361
 362 #ifdef CONFIG_BLK_DEV_ZONED
 363 void blk_queue_free_zone_bitmaps(struct request_queue *q);
 364 #else
 365 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
 366 #endif
 367
 368 #endif /* BLK_INTERNAL_H */