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