xref: /linux/block/blk.h (revision 2634682fdffd9ba6e74b76be8aa91cf8b2e05c41)
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 <linux/blk-crypto.h>
9 #include <xen/xen.h>
10 #include "blk-crypto-internal.h"
11 #include "blk-mq.h"
12 #include "blk-mq-sched.h"
13 
14 /* Max future timer expiry for timeouts */
15 #define BLK_MAX_TIMEOUT		(5 * HZ)
16 
17 extern struct dentry *blk_debugfs_root;
18 
19 struct blk_flush_queue {
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 	struct lock_class_key	key;
29 	spinlock_t		mq_flush_lock;
30 };
31 
32 extern struct kmem_cache *blk_requestq_cachep;
33 extern struct kobj_type blk_queue_ktype;
34 extern struct ida blk_queue_ida;
35 
36 static inline struct blk_flush_queue *
37 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
38 {
39 	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
40 }
41 
42 static inline void __blk_get_queue(struct request_queue *q)
43 {
44 	kobject_get(&q->kobj);
45 }
46 
47 static inline bool
48 is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
49 {
50 	return hctx->fq->flush_rq == req;
51 }
52 
53 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
54 					      gfp_t flags);
55 void blk_free_flush_queue(struct blk_flush_queue *q);
56 
57 void blk_freeze_queue(struct request_queue *q);
58 
59 static inline bool biovec_phys_mergeable(struct request_queue *q,
60 		struct bio_vec *vec1, struct bio_vec *vec2)
61 {
62 	unsigned long mask = queue_segment_boundary(q);
63 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
64 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
65 
66 	if (addr1 + vec1->bv_len != addr2)
67 		return false;
68 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
69 		return false;
70 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
71 		return false;
72 	return true;
73 }
74 
75 static inline bool __bvec_gap_to_prev(struct request_queue *q,
76 		struct bio_vec *bprv, unsigned int offset)
77 {
78 	return (offset & queue_virt_boundary(q)) ||
79 		((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
80 }
81 
82 /*
83  * Check if adding a bio_vec after bprv with offset would create a gap in
84  * the SG list. Most drivers don't care about this, but some do.
85  */
86 static inline bool bvec_gap_to_prev(struct request_queue *q,
87 		struct bio_vec *bprv, unsigned int offset)
88 {
89 	if (!queue_virt_boundary(q))
90 		return false;
91 	return __bvec_gap_to_prev(q, bprv, offset);
92 }
93 
94 static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
95 		unsigned int nr_segs)
96 {
97 	rq->nr_phys_segments = nr_segs;
98 	rq->__data_len = bio->bi_iter.bi_size;
99 	rq->bio = rq->biotail = bio;
100 	rq->ioprio = bio_prio(bio);
101 
102 	if (bio->bi_disk)
103 		rq->rq_disk = bio->bi_disk;
104 }
105 
106 #ifdef CONFIG_BLK_DEV_INTEGRITY
107 void blk_flush_integrity(void);
108 bool __bio_integrity_endio(struct bio *);
109 void bio_integrity_free(struct bio *bio);
110 static inline bool bio_integrity_endio(struct bio *bio)
111 {
112 	if (bio_integrity(bio))
113 		return __bio_integrity_endio(bio);
114 	return true;
115 }
116 
117 static inline bool integrity_req_gap_back_merge(struct request *req,
118 		struct bio *next)
119 {
120 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
121 	struct bio_integrity_payload *bip_next = bio_integrity(next);
122 
123 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
124 				bip_next->bip_vec[0].bv_offset);
125 }
126 
127 static inline bool integrity_req_gap_front_merge(struct request *req,
128 		struct bio *bio)
129 {
130 	struct bio_integrity_payload *bip = bio_integrity(bio);
131 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
132 
133 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
134 				bip_next->bip_vec[0].bv_offset);
135 }
136 
137 void blk_integrity_add(struct gendisk *);
138 void blk_integrity_del(struct gendisk *);
139 #else /* CONFIG_BLK_DEV_INTEGRITY */
140 static inline bool integrity_req_gap_back_merge(struct request *req,
141 		struct bio *next)
142 {
143 	return false;
144 }
145 static inline bool integrity_req_gap_front_merge(struct request *req,
146 		struct bio *bio)
147 {
148 	return false;
149 }
150 
151 static inline void blk_flush_integrity(void)
152 {
153 }
154 static inline bool bio_integrity_endio(struct bio *bio)
155 {
156 	return true;
157 }
158 static inline void bio_integrity_free(struct bio *bio)
159 {
160 }
161 static inline void blk_integrity_add(struct gendisk *disk)
162 {
163 }
164 static inline void blk_integrity_del(struct gendisk *disk)
165 {
166 }
167 #endif /* CONFIG_BLK_DEV_INTEGRITY */
168 
169 unsigned long blk_rq_timeout(unsigned long timeout);
170 void blk_add_timer(struct request *req);
171 
172 bool bio_attempt_front_merge(struct request *req, struct bio *bio,
173 		unsigned int nr_segs);
174 bool bio_attempt_back_merge(struct request *req, struct bio *bio,
175 		unsigned int nr_segs);
176 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
177 		struct bio *bio);
178 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
179 		unsigned int nr_segs, struct request **same_queue_rq);
180 
181 void blk_account_io_start(struct request *req);
182 void blk_account_io_done(struct request *req, u64 now);
183 
184 /*
185  * Internal elevator interface
186  */
187 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
188 
189 void blk_insert_flush(struct request *rq);
190 
191 void elevator_init_mq(struct request_queue *q);
192 int elevator_switch_mq(struct request_queue *q,
193 			      struct elevator_type *new_e);
194 void __elevator_exit(struct request_queue *, struct elevator_queue *);
195 int elv_register_queue(struct request_queue *q, bool uevent);
196 void elv_unregister_queue(struct request_queue *q);
197 
198 static inline void elevator_exit(struct request_queue *q,
199 		struct elevator_queue *e)
200 {
201 	lockdep_assert_held(&q->sysfs_lock);
202 
203 	blk_mq_sched_free_requests(q);
204 	__elevator_exit(q, e);
205 }
206 
207 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
208 
209 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
210 		char *buf);
211 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
212 		char *buf);
213 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
214 		char *buf);
215 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
216 		char *buf);
217 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
218 		const char *buf, size_t count);
219 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
220 ssize_t part_timeout_store(struct device *, struct device_attribute *,
221 				const char *, size_t);
222 
223 void __blk_queue_split(struct bio **bio, unsigned int *nr_segs);
224 int ll_back_merge_fn(struct request *req, struct bio *bio,
225 		unsigned int nr_segs);
226 int ll_front_merge_fn(struct request *req,  struct bio *bio,
227 		unsigned int nr_segs);
228 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
229 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
230 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
231 				struct request *next);
232 unsigned int blk_recalc_rq_segments(struct request *rq);
233 void blk_rq_set_mixed_merge(struct request *rq);
234 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
235 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
236 
237 int blk_dev_init(void);
238 
239 /*
240  * Contribute to IO statistics IFF:
241  *
242  *	a) it's attached to a gendisk, and
243  *	b) the queue had IO stats enabled when this request was started
244  */
245 static inline bool blk_do_io_stat(struct request *rq)
246 {
247 	return rq->rq_disk && (rq->rq_flags & RQF_IO_STAT);
248 }
249 
250 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
251 {
252 	req->cmd_flags |= REQ_NOMERGE;
253 	if (req == q->last_merge)
254 		q->last_merge = NULL;
255 }
256 
257 /*
258  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
259  * is defined as 'unsigned int', meantime it has to aligned to with logical
260  * block size which is the minimum accepted unit by hardware.
261  */
262 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
263 {
264 	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
265 }
266 
267 /*
268  * The max bio size which is aligned to q->limits.discard_granularity. This
269  * is a hint to split large discard bio in generic block layer, then if device
270  * driver needs to split the discard bio into smaller ones, their bi_size can
271  * be very probably and easily aligned to discard_granularity of the device's
272  * queue.
273  */
274 static inline unsigned int bio_aligned_discard_max_sectors(
275 					struct request_queue *q)
276 {
277 	return round_down(UINT_MAX, q->limits.discard_granularity) >>
278 			SECTOR_SHIFT;
279 }
280 
281 /*
282  * Internal io_context interface
283  */
284 void get_io_context(struct io_context *ioc);
285 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
286 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
287 			     gfp_t gfp_mask);
288 void ioc_clear_queue(struct request_queue *q);
289 
290 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
291 
292 /*
293  * Internal throttling interface
294  */
295 #ifdef CONFIG_BLK_DEV_THROTTLING
296 extern int blk_throtl_init(struct request_queue *q);
297 extern void blk_throtl_exit(struct request_queue *q);
298 extern void blk_throtl_register_queue(struct request_queue *q);
299 bool blk_throtl_bio(struct bio *bio);
300 #else /* CONFIG_BLK_DEV_THROTTLING */
301 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
302 static inline void blk_throtl_exit(struct request_queue *q) { }
303 static inline void blk_throtl_register_queue(struct request_queue *q) { }
304 static inline bool blk_throtl_bio(struct bio *bio) { return false; }
305 #endif /* CONFIG_BLK_DEV_THROTTLING */
306 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
307 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
308 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
309 	const char *page, size_t count);
310 extern void blk_throtl_bio_endio(struct bio *bio);
311 extern void blk_throtl_stat_add(struct request *rq, u64 time);
312 #else
313 static inline void blk_throtl_bio_endio(struct bio *bio) { }
314 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
315 #endif
316 
317 #ifdef CONFIG_BOUNCE
318 extern int init_emergency_isa_pool(void);
319 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
320 #else
321 static inline int init_emergency_isa_pool(void)
322 {
323 	return 0;
324 }
325 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
326 {
327 }
328 #endif /* CONFIG_BOUNCE */
329 
330 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
331 extern int blk_iolatency_init(struct request_queue *q);
332 #else
333 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
334 #endif
335 
336 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
337 
338 #ifdef CONFIG_BLK_DEV_ZONED
339 void blk_queue_free_zone_bitmaps(struct request_queue *q);
340 #else
341 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
342 #endif
343 
344 struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector);
345 
346 int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
347 void blk_free_devt(dev_t devt);
348 void blk_invalidate_devt(dev_t devt);
349 char *disk_name(struct gendisk *hd, int partno, char *buf);
350 #define ADDPART_FLAG_NONE	0
351 #define ADDPART_FLAG_RAID	1
352 #define ADDPART_FLAG_WHOLEDISK	2
353 void delete_partition(struct gendisk *disk, struct hd_struct *part);
354 int bdev_add_partition(struct block_device *bdev, int partno,
355 		sector_t start, sector_t length);
356 int bdev_del_partition(struct block_device *bdev, int partno);
357 int bdev_resize_partition(struct block_device *bdev, int partno,
358 		sector_t start, sector_t length);
359 int disk_expand_part_tbl(struct gendisk *disk, int target);
360 int hd_ref_init(struct hd_struct *part);
361 
362 /* no need to get/put refcount of part0 */
363 static inline int hd_struct_try_get(struct hd_struct *part)
364 {
365 	if (part->partno)
366 		return percpu_ref_tryget_live(&part->ref);
367 	return 1;
368 }
369 
370 static inline void hd_struct_put(struct hd_struct *part)
371 {
372 	if (part->partno)
373 		percpu_ref_put(&part->ref);
374 }
375 
376 static inline void hd_free_part(struct hd_struct *part)
377 {
378 	free_percpu(part->dkstats);
379 	kfree(part->info);
380 	percpu_ref_exit(&part->ref);
381 }
382 
383 /*
384  * Any access of part->nr_sects which is not protected by partition
385  * bd_mutex or gendisk bdev bd_mutex, should be done using this
386  * accessor function.
387  *
388  * Code written along the lines of i_size_read() and i_size_write().
389  * CONFIG_PREEMPTION case optimizes the case of UP kernel with preemption
390  * on.
391  */
392 static inline sector_t part_nr_sects_read(struct hd_struct *part)
393 {
394 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
395 	sector_t nr_sects;
396 	unsigned seq;
397 	do {
398 		seq = read_seqcount_begin(&part->nr_sects_seq);
399 		nr_sects = part->nr_sects;
400 	} while (read_seqcount_retry(&part->nr_sects_seq, seq));
401 	return nr_sects;
402 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
403 	sector_t nr_sects;
404 
405 	preempt_disable();
406 	nr_sects = part->nr_sects;
407 	preempt_enable();
408 	return nr_sects;
409 #else
410 	return part->nr_sects;
411 #endif
412 }
413 
414 /*
415  * Should be called with mutex lock held (typically bd_mutex) of partition
416  * to provide mutual exlusion among writers otherwise seqcount might be
417  * left in wrong state leaving the readers spinning infinitely.
418  */
419 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
420 {
421 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
422 	preempt_disable();
423 	write_seqcount_begin(&part->nr_sects_seq);
424 	part->nr_sects = size;
425 	write_seqcount_end(&part->nr_sects_seq);
426 	preempt_enable();
427 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
428 	preempt_disable();
429 	part->nr_sects = size;
430 	preempt_enable();
431 #else
432 	part->nr_sects = size;
433 #endif
434 }
435 
436 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
437 		struct page *page, unsigned int len, unsigned int offset,
438 		unsigned int max_sectors, bool *same_page);
439 
440 #endif /* BLK_INTERNAL_H */
441