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TOMOYO Linux Cross Reference
Linux/block/blk.h

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  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 <linux/part_stat.h>
  8 #include <xen/xen.h>
  9 #include "blk-mq.h"
 10 #include "blk-mq-sched.h"
 11 
 12 /* Max future timer expiry for timeouts */
 13 #define BLK_MAX_TIMEOUT         (5 * HZ)
 14 
 15 #ifdef CONFIG_DEBUG_FS
 16 extern struct dentry *blk_debugfs_root;
 17 #endif
 18 
 19 struct blk_flush_queue {
 20         unsigned int            flush_queue_delayed:1;
 21         unsigned int            flush_pending_idx:1;
 22         unsigned int            flush_running_idx:1;
 23         blk_status_t            rq_status;
 24         unsigned long           flush_pending_since;
 25         struct list_head        flush_queue[2];
 26         struct list_head        flush_data_in_flight;
 27         struct request          *flush_rq;
 28 
 29         /*
 30          * flush_rq shares tag with this rq, both can't be active
 31          * at the same time
 32          */
 33         struct request          *orig_rq;
 34         struct lock_class_key   key;
 35         spinlock_t              mq_flush_lock;
 36 };
 37 
 38 extern struct kmem_cache *blk_requestq_cachep;
 39 extern struct kobj_type blk_queue_ktype;
 40 extern struct ida blk_queue_ida;
 41 
 42 static inline struct blk_flush_queue *
 43 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
 44 {
 45         return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
 46 }
 47 
 48 static inline void __blk_get_queue(struct request_queue *q)
 49 {
 50         kobject_get(&q->kobj);
 51 }
 52 
 53 static inline bool
 54 is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
 55 {
 56         return hctx->fq->flush_rq == req;
 57 }
 58 
 59 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
 60                                               gfp_t flags);
 61 void blk_free_flush_queue(struct blk_flush_queue *q);
 62 
 63 void blk_freeze_queue(struct request_queue *q);
 64 
 65 static inline void blk_queue_enter_live(struct request_queue *q)
 66 {
 67         /*
 68          * Given that running in generic_make_request() context
 69          * guarantees that a live reference against q_usage_counter has
 70          * been established, further references under that same context
 71          * need not check that the queue has been frozen (marked dead).
 72          */
 73         percpu_ref_get(&q->q_usage_counter);
 74 }
 75 
 76 static inline bool biovec_phys_mergeable(struct request_queue *q,
 77                 struct bio_vec *vec1, struct bio_vec *vec2)
 78 {
 79         unsigned long mask = queue_segment_boundary(q);
 80         phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
 81         phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
 82 
 83         if (addr1 + vec1->bv_len != addr2)
 84                 return false;
 85         if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
 86                 return false;
 87         if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
 88                 return false;
 89         return true;
 90 }
 91 
 92 static inline bool __bvec_gap_to_prev(struct request_queue *q,
 93                 struct bio_vec *bprv, unsigned int offset)
 94 {
 95         return (offset & queue_virt_boundary(q)) ||
 96                 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
 97 }
 98 
 99 /*
100  * Check if adding a bio_vec after bprv with offset would create a gap in
101  * the SG list. Most drivers don't care about this, but some do.
102  */
103 static inline bool bvec_gap_to_prev(struct request_queue *q,
104                 struct bio_vec *bprv, unsigned int offset)
105 {
106         if (!queue_virt_boundary(q))
107                 return false;
108         return __bvec_gap_to_prev(q, bprv, offset);
109 }
110 
111 static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
112                 unsigned int nr_segs)
113 {
114         rq->nr_phys_segments = nr_segs;
115         rq->__data_len = bio->bi_iter.bi_size;
116         rq->bio = rq->biotail = bio;
117         rq->ioprio = bio_prio(bio);
118 
119         if (bio->bi_disk)
120                 rq->rq_disk = bio->bi_disk;
121 }
122 
123 #ifdef CONFIG_BLK_DEV_INTEGRITY
124 void blk_flush_integrity(void);
125 bool __bio_integrity_endio(struct bio *);
126 void bio_integrity_free(struct bio *bio);
127 static inline bool bio_integrity_endio(struct bio *bio)
128 {
129         if (bio_integrity(bio))
130                 return __bio_integrity_endio(bio);
131         return true;
132 }
133 
134 static inline bool integrity_req_gap_back_merge(struct request *req,
135                 struct bio *next)
136 {
137         struct bio_integrity_payload *bip = bio_integrity(req->bio);
138         struct bio_integrity_payload *bip_next = bio_integrity(next);
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 
144 static inline bool integrity_req_gap_front_merge(struct request *req,
145                 struct bio *bio)
146 {
147         struct bio_integrity_payload *bip = bio_integrity(bio);
148         struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
149 
150         return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
151                                 bip_next->bip_vec[0].bv_offset);
152 }
153 
154 void blk_integrity_add(struct gendisk *);
155 void blk_integrity_del(struct gendisk *);
156 #else /* CONFIG_BLK_DEV_INTEGRITY */
157 static inline bool integrity_req_gap_back_merge(struct request *req,
158                 struct bio *next)
159 {
160         return false;
161 }
162 static inline bool integrity_req_gap_front_merge(struct request *req,
163                 struct bio *bio)
164 {
165         return false;
166 }
167 
168 static inline void blk_flush_integrity(void)
169 {
170 }
171 static inline bool bio_integrity_endio(struct bio *bio)
172 {
173         return true;
174 }
175 static inline void bio_integrity_free(struct bio *bio)
176 {
177 }
178 static inline void blk_integrity_add(struct gendisk *disk)
179 {
180 }
181 static inline void blk_integrity_del(struct gendisk *disk)
182 {
183 }
184 #endif /* CONFIG_BLK_DEV_INTEGRITY */
185 
186 unsigned long blk_rq_timeout(unsigned long timeout);
187 void blk_add_timer(struct request *req);
188 
189 bool bio_attempt_front_merge(struct request *req, struct bio *bio,
190                 unsigned int nr_segs);
191 bool bio_attempt_back_merge(struct request *req, struct bio *bio,
192                 unsigned int nr_segs);
193 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
194                 struct bio *bio);
195 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
196                 unsigned int nr_segs, struct request **same_queue_rq);
197 
198 void blk_account_io_start(struct request *req, bool new_io);
199 void blk_account_io_completion(struct request *req, unsigned int bytes);
200 void blk_account_io_done(struct request *req, u64 now);
201 
202 /*
203  * Internal elevator interface
204  */
205 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
206 
207 void blk_insert_flush(struct request *rq);
208 
209 void elevator_init_mq(struct request_queue *q);
210 int elevator_switch_mq(struct request_queue *q,
211                               struct elevator_type *new_e);
212 void __elevator_exit(struct request_queue *, struct elevator_queue *);
213 int elv_register_queue(struct request_queue *q, bool uevent);
214 void elv_unregister_queue(struct request_queue *q);
215 
216 static inline void elevator_exit(struct request_queue *q,
217                 struct elevator_queue *e)
218 {
219         lockdep_assert_held(&q->sysfs_lock);
220 
221         blk_mq_sched_free_requests(q);
222         __elevator_exit(q, e);
223 }
224 
225 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
226 
227 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
228                 char *buf);
229 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
230                 char *buf);
231 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
232                 char *buf);
233 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
234                 char *buf);
235 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
236                 const char *buf, size_t count);
237 
238 #ifdef CONFIG_FAIL_IO_TIMEOUT
239 int blk_should_fake_timeout(struct request_queue *);
240 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
241 ssize_t part_timeout_store(struct device *, struct device_attribute *,
242                                 const char *, size_t);
243 #else
244 static inline int blk_should_fake_timeout(struct request_queue *q)
245 {
246         return 0;
247 }
248 #endif
249 
250 void __blk_queue_split(struct request_queue *q, struct bio **bio,
251                 unsigned int *nr_segs);
252 int ll_back_merge_fn(struct request *req, struct bio *bio,
253                 unsigned int nr_segs);
254 int ll_front_merge_fn(struct request *req,  struct bio *bio,
255                 unsigned int nr_segs);
256 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
257 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
258 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
259                                 struct request *next);
260 unsigned int blk_recalc_rq_segments(struct request *rq);
261 void blk_rq_set_mixed_merge(struct request *rq);
262 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
263 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
264 
265 int blk_dev_init(void);
266 
267 /*
268  * Contribute to IO statistics IFF:
269  *
270  *      a) it's attached to a gendisk, and
271  *      b) the queue had IO stats enabled when this request was started
272  */
273 static inline bool blk_do_io_stat(struct request *rq)
274 {
275         return rq->rq_disk && (rq->rq_flags & RQF_IO_STAT);
276 }
277 
278 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
279 {
280         req->cmd_flags |= REQ_NOMERGE;
281         if (req == q->last_merge)
282                 q->last_merge = NULL;
283 }
284 
285 /*
286  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
287  * is defined as 'unsigned int', meantime it has to aligned to with logical
288  * block size which is the minimum accepted unit by hardware.
289  */
290 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
291 {
292         return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
293 }
294 
295 /*
296  * Internal io_context interface
297  */
298 void get_io_context(struct io_context *ioc);
299 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
300 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
301                              gfp_t gfp_mask);
302 void ioc_clear_queue(struct request_queue *q);
303 
304 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
305 
306 /**
307  * create_io_context - try to create task->io_context
308  * @gfp_mask: allocation mask
309  * @node: allocation node
310  *
311  * If %current->io_context is %NULL, allocate a new io_context and install
312  * it.  Returns the current %current->io_context which may be %NULL if
313  * allocation failed.
314  *
315  * Note that this function can't be called with IRQ disabled because
316  * task_lock which protects %current->io_context is IRQ-unsafe.
317  */
318 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
319 {
320         WARN_ON_ONCE(irqs_disabled());
321         if (unlikely(!current->io_context))
322                 create_task_io_context(current, gfp_mask, node);
323         return current->io_context;
324 }
325 
326 /*
327  * Internal throttling interface
328  */
329 #ifdef CONFIG_BLK_DEV_THROTTLING
330 extern void blk_throtl_drain(struct request_queue *q);
331 extern int blk_throtl_init(struct request_queue *q);
332 extern void blk_throtl_exit(struct request_queue *q);
333 extern void blk_throtl_register_queue(struct request_queue *q);
334 #else /* CONFIG_BLK_DEV_THROTTLING */
335 static inline void blk_throtl_drain(struct request_queue *q) { }
336 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
337 static inline void blk_throtl_exit(struct request_queue *q) { }
338 static inline void blk_throtl_register_queue(struct request_queue *q) { }
339 #endif /* CONFIG_BLK_DEV_THROTTLING */
340 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
341 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
342 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
343         const char *page, size_t count);
344 extern void blk_throtl_bio_endio(struct bio *bio);
345 extern void blk_throtl_stat_add(struct request *rq, u64 time);
346 #else
347 static inline void blk_throtl_bio_endio(struct bio *bio) { }
348 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
349 #endif
350 
351 #ifdef CONFIG_BOUNCE
352 extern int init_emergency_isa_pool(void);
353 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
354 #else
355 static inline int init_emergency_isa_pool(void)
356 {
357         return 0;
358 }
359 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
360 {
361 }
362 #endif /* CONFIG_BOUNCE */
363 
364 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
365 extern int blk_iolatency_init(struct request_queue *q);
366 #else
367 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
368 #endif
369 
370 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
371 
372 #ifdef CONFIG_BLK_DEV_ZONED
373 void blk_queue_free_zone_bitmaps(struct request_queue *q);
374 #else
375 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
376 #endif
377 
378 void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
379                         int rw);
380 void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
381                         int rw);
382 void update_io_ticks(struct hd_struct *part, unsigned long now, bool end);
383 struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector);
384 
385 int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
386 void blk_free_devt(dev_t devt);
387 void blk_invalidate_devt(dev_t devt);
388 char *disk_name(struct gendisk *hd, int partno, char *buf);
389 #define ADDPART_FLAG_NONE       0
390 #define ADDPART_FLAG_RAID       1
391 #define ADDPART_FLAG_WHOLEDISK  2
392 struct hd_struct *__must_check add_partition(struct gendisk *disk, int partno,
393                 sector_t start, sector_t len, int flags,
394                 struct partition_meta_info *info);
395 void __delete_partition(struct percpu_ref *ref);
396 void delete_partition(struct gendisk *disk, int partno);
397 int disk_expand_part_tbl(struct gendisk *disk, int target);
398 
399 static inline int hd_ref_init(struct hd_struct *part)
400 {
401         if (percpu_ref_init(&part->ref, __delete_partition, 0,
402                                 GFP_KERNEL))
403                 return -ENOMEM;
404         return 0;
405 }
406 
407 static inline void hd_struct_get(struct hd_struct *part)
408 {
409         percpu_ref_get(&part->ref);
410 }
411 
412 static inline int hd_struct_try_get(struct hd_struct *part)
413 {
414         return percpu_ref_tryget_live(&part->ref);
415 }
416 
417 static inline void hd_struct_put(struct hd_struct *part)
418 {
419         percpu_ref_put(&part->ref);
420 }
421 
422 static inline void hd_struct_kill(struct hd_struct *part)
423 {
424         percpu_ref_kill(&part->ref);
425 }
426 
427 static inline void hd_free_part(struct hd_struct *part)
428 {
429         free_part_stats(part);
430         kfree(part->info);
431         percpu_ref_exit(&part->ref);
432 }
433 
434 /*
435  * Any access of part->nr_sects which is not protected by partition
436  * bd_mutex or gendisk bdev bd_mutex, should be done using this
437  * accessor function.
438  *
439  * Code written along the lines of i_size_read() and i_size_write().
440  * CONFIG_PREEMPTION case optimizes the case of UP kernel with preemption
441  * on.
442  */
443 static inline sector_t part_nr_sects_read(struct hd_struct *part)
444 {
445 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
446         sector_t nr_sects;
447         unsigned seq;
448         do {
449                 seq = read_seqcount_begin(&part->nr_sects_seq);
450                 nr_sects = part->nr_sects;
451         } while (read_seqcount_retry(&part->nr_sects_seq, seq));
452         return nr_sects;
453 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
454         sector_t nr_sects;
455 
456         preempt_disable();
457         nr_sects = part->nr_sects;
458         preempt_enable();
459         return nr_sects;
460 #else
461         return part->nr_sects;
462 #endif
463 }
464 
465 /*
466  * Should be called with mutex lock held (typically bd_mutex) of partition
467  * to provide mutual exlusion among writers otherwise seqcount might be
468  * left in wrong state leaving the readers spinning infinitely.
469  */
470 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
471 {
472 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
473         preempt_disable();
474         write_seqcount_begin(&part->nr_sects_seq);
475         part->nr_sects = size;
476         write_seqcount_end(&part->nr_sects_seq);
477         preempt_enable();
478 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
479         preempt_disable();
480         part->nr_sects = size;
481         preempt_enable();
482 #else
483         part->nr_sects = size;
484 #endif
485 }
486 
487 struct request_queue *__blk_alloc_queue(int node_id);
488 
489 int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
490                 struct page *page, unsigned int len, unsigned int offset,
491                 bool *same_page);
492 
493 #endif /* BLK_INTERNAL_H */
494 

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