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