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