xref: /linux/block/blk.h (revision 6dfafbd0299a60bfb5d5e277fdf100037c7ded07)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef BLK_INTERNAL_H
3 #define BLK_INTERNAL_H
4 
5 #include <linux/bio-integrity.h>
6 #include <linux/blk-crypto.h>
7 #include <linux/lockdep.h>
8 #include <linux/memblock.h>	/* for max_pfn/max_low_pfn */
9 #include <linux/sched/sysctl.h>
10 #include <linux/timekeeping.h>
11 #include <xen/xen.h>
12 #include "blk-crypto-internal.h"
13 
14 struct elv_change_ctx;
15 
16 /*
17  * Default upper limit for the software max_sectors limit used for regular I/Os.
18  * This can be increased through sysfs.
19  *
20  * This should not be confused with the max_hw_sector limit that is entirely
21  * controlled by the block device driver, usually based on hardware limits.
22  */
23 #define BLK_DEF_MAX_SECTORS_CAP	(SZ_4M >> SECTOR_SHIFT)
24 
25 #define	BLK_DEV_MAX_SECTORS	(LLONG_MAX >> 9)
26 #define	BLK_MIN_SEGMENT_SIZE	4096
27 
28 /* Max future timer expiry for timeouts */
29 #define BLK_MAX_TIMEOUT		(5 * HZ)
30 
31 extern const struct kobj_type blk_queue_ktype;
32 extern struct dentry *blk_debugfs_root;
33 
34 struct blk_flush_queue {
35 	spinlock_t		mq_flush_lock;
36 	unsigned int		flush_pending_idx:1;
37 	unsigned int		flush_running_idx:1;
38 	blk_status_t 		rq_status;
39 	unsigned long		flush_pending_since;
40 	struct list_head	flush_queue[2];
41 	unsigned long		flush_data_in_flight;
42 	struct request		*flush_rq;
43 	struct rcu_head		rcu_head;
44 };
45 
46 bool is_flush_rq(struct request *req);
47 
48 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
49 					      gfp_t flags);
50 void blk_free_flush_queue(struct blk_flush_queue *q);
51 
52 bool __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
53 bool blk_queue_start_drain(struct request_queue *q);
54 bool __blk_freeze_queue_start(struct request_queue *q,
55 			      struct task_struct *owner);
56 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
57 void submit_bio_noacct_nocheck(struct bio *bio, bool split);
58 void bio_await_chain(struct bio *bio);
59 
60 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
61 {
62 	rcu_read_lock();
63 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
64 		goto fail;
65 
66 	/*
67 	 * The code that increments the pm_only counter must ensure that the
68 	 * counter is globally visible before the queue is unfrozen.
69 	 */
70 	if (blk_queue_pm_only(q) &&
71 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
72 		goto fail_put;
73 
74 	rcu_read_unlock();
75 	return true;
76 
77 fail_put:
78 	blk_queue_exit(q);
79 fail:
80 	rcu_read_unlock();
81 	return false;
82 }
83 
84 static inline int bio_queue_enter(struct bio *bio)
85 {
86 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
87 
88 	if (blk_try_enter_queue(q, false)) {
89 		rwsem_acquire_read(&q->io_lockdep_map, 0, 0, _RET_IP_);
90 		rwsem_release(&q->io_lockdep_map, _RET_IP_);
91 		return 0;
92 	}
93 	return __bio_queue_enter(q, bio);
94 }
95 
96 static inline void blk_wait_io(struct completion *done)
97 {
98 	/* Prevent hang_check timer from firing at us during very long I/O */
99 	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
100 
101 	if (timeout)
102 		while (!wait_for_completion_io_timeout(done, timeout))
103 			;
104 	else
105 		wait_for_completion_io(done);
106 }
107 
108 struct block_device *blkdev_get_no_open(dev_t dev, bool autoload);
109 void blkdev_put_no_open(struct block_device *bdev);
110 
111 #define BIO_INLINE_VECS 4
112 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
113 		gfp_t gfp_mask);
114 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
115 
116 bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
117 		struct page *page, unsigned len, unsigned offset);
118 
119 static inline bool biovec_phys_mergeable(struct request_queue *q,
120 		struct bio_vec *vec1, struct bio_vec *vec2)
121 {
122 	unsigned long mask = queue_segment_boundary(q);
123 	phys_addr_t addr1 = bvec_phys(vec1);
124 	phys_addr_t addr2 = bvec_phys(vec2);
125 
126 	/*
127 	 * Merging adjacent physical pages may not work correctly under KMSAN
128 	 * if their metadata pages aren't adjacent. Just disable merging.
129 	 */
130 	if (IS_ENABLED(CONFIG_KMSAN))
131 		return false;
132 
133 	if (addr1 + vec1->bv_len != addr2)
134 		return false;
135 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
136 		return false;
137 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
138 		return false;
139 	return true;
140 }
141 
142 static inline bool __bvec_gap_to_prev(const struct queue_limits *lim,
143 		struct bio_vec *bprv, unsigned int offset)
144 {
145 	return (offset & lim->virt_boundary_mask) ||
146 		((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask);
147 }
148 
149 /*
150  * Check if adding a bio_vec after bprv with offset would create a gap in
151  * the SG list. Most drivers don't care about this, but some do.
152  */
153 static inline bool bvec_gap_to_prev(const struct queue_limits *lim,
154 		struct bio_vec *bprv, unsigned int offset)
155 {
156 	if (!lim->virt_boundary_mask)
157 		return false;
158 	return __bvec_gap_to_prev(lim, bprv, offset);
159 }
160 
161 static inline bool rq_mergeable(struct request *rq)
162 {
163 	if (blk_rq_is_passthrough(rq))
164 		return false;
165 
166 	if (req_op(rq) == REQ_OP_FLUSH)
167 		return false;
168 
169 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
170 		return false;
171 
172 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
173 		return false;
174 
175 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
176 		return false;
177 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
178 		return false;
179 
180 	return true;
181 }
182 
183 /*
184  * There are two different ways to handle DISCARD merges:
185  *  1) If max_discard_segments > 1, the driver treats every bio as a range and
186  *     send the bios to controller together. The ranges don't need to be
187  *     contiguous.
188  *  2) Otherwise, the request will be normal read/write requests.  The ranges
189  *     need to be contiguous.
190  */
191 static inline bool blk_discard_mergable(struct request *req)
192 {
193 	if (req_op(req) == REQ_OP_DISCARD &&
194 	    queue_max_discard_segments(req->q) > 1)
195 		return true;
196 	return false;
197 }
198 
199 static inline unsigned int blk_rq_get_max_segments(struct request *rq)
200 {
201 	if (req_op(rq) == REQ_OP_DISCARD)
202 		return queue_max_discard_segments(rq->q);
203 	return queue_max_segments(rq->q);
204 }
205 
206 static inline unsigned int blk_queue_get_max_sectors(struct request *rq)
207 {
208 	struct request_queue *q = rq->q;
209 	enum req_op op = req_op(rq);
210 
211 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
212 		return min(q->limits.max_discard_sectors,
213 			   UINT_MAX >> SECTOR_SHIFT);
214 
215 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
216 		return q->limits.max_write_zeroes_sectors;
217 
218 	if (rq->cmd_flags & REQ_ATOMIC)
219 		return q->limits.atomic_write_max_sectors;
220 
221 	return q->limits.max_sectors;
222 }
223 
224 #ifdef CONFIG_BLK_DEV_INTEGRITY
225 void blk_flush_integrity(void);
226 void bio_integrity_free(struct bio *bio);
227 
228 /*
229  * Integrity payloads can either be owned by the submitter, in which case
230  * bio_uninit will free them, or owned and generated by the block layer,
231  * in which case we'll verify them here (for reads) and free them before
232  * the bio is handed back to the submitted.
233  */
234 bool __bio_integrity_endio(struct bio *bio);
235 static inline bool bio_integrity_endio(struct bio *bio)
236 {
237 	struct bio_integrity_payload *bip = bio_integrity(bio);
238 
239 	if (bip && (bip->bip_flags & BIP_BLOCK_INTEGRITY))
240 		return __bio_integrity_endio(bio);
241 	return true;
242 }
243 
244 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
245 		struct request *);
246 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
247 		struct bio *);
248 
249 static inline bool integrity_req_gap_back_merge(struct request *req,
250 		struct bio *next)
251 {
252 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
253 	struct bio_integrity_payload *bip_next = bio_integrity(next);
254 
255 	return bvec_gap_to_prev(&req->q->limits,
256 				&bip->bip_vec[bip->bip_vcnt - 1],
257 				bip_next->bip_vec[0].bv_offset);
258 }
259 
260 static inline bool integrity_req_gap_front_merge(struct request *req,
261 		struct bio *bio)
262 {
263 	struct bio_integrity_payload *bip = bio_integrity(bio);
264 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
265 
266 	return bvec_gap_to_prev(&req->q->limits,
267 				&bip->bip_vec[bip->bip_vcnt - 1],
268 				bip_next->bip_vec[0].bv_offset);
269 }
270 
271 extern const struct attribute_group blk_integrity_attr_group;
272 #else /* CONFIG_BLK_DEV_INTEGRITY */
273 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
274 		struct request *r1, struct request *r2)
275 {
276 	return true;
277 }
278 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
279 		struct request *r, struct bio *b)
280 {
281 	return true;
282 }
283 static inline bool integrity_req_gap_back_merge(struct request *req,
284 		struct bio *next)
285 {
286 	return false;
287 }
288 static inline bool integrity_req_gap_front_merge(struct request *req,
289 		struct bio *bio)
290 {
291 	return false;
292 }
293 
294 static inline void blk_flush_integrity(void)
295 {
296 }
297 static inline bool bio_integrity_endio(struct bio *bio)
298 {
299 	return true;
300 }
301 static inline void bio_integrity_free(struct bio *bio)
302 {
303 }
304 #endif /* CONFIG_BLK_DEV_INTEGRITY */
305 
306 unsigned long blk_rq_timeout(unsigned long timeout);
307 void blk_add_timer(struct request *req);
308 
309 enum bio_merge_status {
310 	BIO_MERGE_OK,
311 	BIO_MERGE_NONE,
312 	BIO_MERGE_FAILED,
313 };
314 
315 enum bio_merge_status bio_attempt_back_merge(struct request *req,
316 		struct bio *bio, unsigned int nr_segs);
317 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
318 		unsigned int nr_segs);
319 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
320 			struct bio *bio, unsigned int nr_segs);
321 
322 /*
323  * Plug flush limits
324  */
325 #define BLK_MAX_REQUEST_COUNT	32
326 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
327 
328 /*
329  * Internal elevator interface
330  */
331 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
332 
333 bool blk_insert_flush(struct request *rq);
334 
335 void elv_update_nr_hw_queues(struct request_queue *q,
336 		struct elv_change_ctx *ctx);
337 void elevator_set_default(struct request_queue *q);
338 void elevator_set_none(struct request_queue *q);
339 
340 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
341 		char *buf);
342 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
343 		char *buf);
344 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
345 		char *buf);
346 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
347 		char *buf);
348 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
349 		const char *buf, size_t count);
350 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
351 ssize_t part_timeout_store(struct device *, struct device_attribute *,
352 				const char *, size_t);
353 
354 struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,
355 		unsigned *nsegs);
356 struct bio *bio_split_write_zeroes(struct bio *bio,
357 		const struct queue_limits *lim, unsigned *nsegs);
358 struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
359 		unsigned *nr_segs);
360 struct bio *bio_split_zone_append(struct bio *bio,
361 		const struct queue_limits *lim, unsigned *nr_segs);
362 
363 /*
364  * All drivers must accept single-segments bios that are smaller than PAGE_SIZE.
365  *
366  * This is a quick and dirty check that relies on the fact that bi_io_vec[0] is
367  * always valid if a bio has data.  The check might lead to occasional false
368  * positives when bios are cloned, but compared to the performance impact of
369  * cloned bios themselves the loop below doesn't matter anyway.
370  */
371 static inline bool bio_may_need_split(struct bio *bio,
372 		const struct queue_limits *lim)
373 {
374 	if (lim->chunk_sectors)
375 		return true;
376 	if (bio->bi_vcnt != 1)
377 		return true;
378 	return bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset >
379 		lim->max_fast_segment_size;
380 }
381 
382 /**
383  * __bio_split_to_limits - split a bio to fit the queue limits
384  * @bio:     bio to be split
385  * @lim:     queue limits to split based on
386  * @nr_segs: returns the number of segments in the returned bio
387  *
388  * Check if @bio needs splitting based on the queue limits, and if so split off
389  * a bio fitting the limits from the beginning of @bio and return it.  @bio is
390  * shortened to the remainder and re-submitted.
391  *
392  * The split bio is allocated from @q->bio_split, which is provided by the
393  * block layer.
394  */
395 static inline struct bio *__bio_split_to_limits(struct bio *bio,
396 		const struct queue_limits *lim, unsigned int *nr_segs)
397 {
398 	switch (bio_op(bio)) {
399 	case REQ_OP_READ:
400 	case REQ_OP_WRITE:
401 		if (bio_may_need_split(bio, lim))
402 			return bio_split_rw(bio, lim, nr_segs);
403 		*nr_segs = 1;
404 		return bio;
405 	case REQ_OP_ZONE_APPEND:
406 		return bio_split_zone_append(bio, lim, nr_segs);
407 	case REQ_OP_DISCARD:
408 	case REQ_OP_SECURE_ERASE:
409 		return bio_split_discard(bio, lim, nr_segs);
410 	case REQ_OP_WRITE_ZEROES:
411 		return bio_split_write_zeroes(bio, lim, nr_segs);
412 	default:
413 		/* other operations can't be split */
414 		*nr_segs = 0;
415 		return bio;
416 	}
417 }
418 
419 /**
420  * get_max_segment_size() - maximum number of bytes to add as a single segment
421  * @lim: Request queue limits.
422  * @paddr: address of the range to add
423  * @len: maximum length available to add at @paddr
424  *
425  * Returns the maximum number of bytes of the range starting at @paddr that can
426  * be added to a single segment.
427  */
428 static inline unsigned get_max_segment_size(const struct queue_limits *lim,
429 		phys_addr_t paddr, unsigned int len)
430 {
431 	/*
432 	 * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1
433 	 * after having calculated the minimum.
434 	 */
435 	return min_t(unsigned long, len,
436 		min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr),
437 		    (unsigned long)lim->max_segment_size - 1) + 1);
438 }
439 
440 int ll_back_merge_fn(struct request *req, struct bio *bio,
441 		unsigned int nr_segs);
442 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
443 				struct request *next);
444 unsigned int blk_recalc_rq_segments(struct request *rq);
445 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
446 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
447 
448 int blk_set_default_limits(struct queue_limits *lim);
449 void blk_apply_bdi_limits(struct backing_dev_info *bdi,
450 		struct queue_limits *lim);
451 int blk_dev_init(void);
452 
453 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
454 
455 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
456 {
457 	req->cmd_flags |= REQ_NOMERGE;
458 	if (req == q->last_merge)
459 		q->last_merge = NULL;
460 }
461 
462 /*
463  * Internal io_context interface
464  */
465 struct io_cq *ioc_find_get_icq(struct request_queue *q);
466 struct io_cq *ioc_lookup_icq(struct request_queue *q);
467 #ifdef CONFIG_BLK_ICQ
468 void ioc_clear_queue(struct request_queue *q);
469 #else
470 static inline void ioc_clear_queue(struct request_queue *q)
471 {
472 }
473 #endif /* CONFIG_BLK_ICQ */
474 
475 #ifdef CONFIG_BLK_DEV_ZONED
476 void disk_init_zone_resources(struct gendisk *disk);
477 void disk_free_zone_resources(struct gendisk *disk);
478 static inline bool bio_zone_write_plugging(struct bio *bio)
479 {
480 	return bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING);
481 }
482 static inline bool blk_req_bio_is_zone_append(struct request *rq,
483 					      struct bio *bio)
484 {
485 	return req_op(rq) == REQ_OP_ZONE_APPEND ||
486 	       bio_flagged(bio, BIO_EMULATES_ZONE_APPEND);
487 }
488 void blk_zone_write_plug_bio_merged(struct bio *bio);
489 void blk_zone_write_plug_init_request(struct request *rq);
490 void blk_zone_append_update_request_bio(struct request *rq, struct bio *bio);
491 void blk_zone_mgmt_bio_endio(struct bio *bio);
492 void blk_zone_write_plug_bio_endio(struct bio *bio);
493 static inline void blk_zone_bio_endio(struct bio *bio)
494 {
495 	/*
496 	 * Zone management BIOs may impact zone write plugs (e.g. a zone reset
497 	 * changes a zone write plug zone write pointer offset), but these
498 	 * operation do not go through zone write plugging as they may operate
499 	 * on zones that do not have a zone write
500 	 * plug. blk_zone_mgmt_bio_endio() handles the potential changes to zone
501 	 * write plugs that are present.
502 	 */
503 	if (op_is_zone_mgmt(bio_op(bio))) {
504 		blk_zone_mgmt_bio_endio(bio);
505 		return;
506 	}
507 
508 	/*
509 	 * For write BIOs to zoned devices, signal the completion of the BIO so
510 	 * that the next write BIO can be submitted by zone write plugging.
511 	 */
512 	if (bio_zone_write_plugging(bio))
513 		blk_zone_write_plug_bio_endio(bio);
514 }
515 
516 void blk_zone_write_plug_finish_request(struct request *rq);
517 static inline void blk_zone_finish_request(struct request *rq)
518 {
519 	if (rq->rq_flags & RQF_ZONE_WRITE_PLUGGING)
520 		blk_zone_write_plug_finish_request(rq);
521 }
522 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
523 		unsigned long arg);
524 int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
525 		unsigned int cmd, unsigned long arg);
526 #else /* CONFIG_BLK_DEV_ZONED */
527 static inline void disk_init_zone_resources(struct gendisk *disk)
528 {
529 }
530 static inline void disk_free_zone_resources(struct gendisk *disk)
531 {
532 }
533 static inline bool bio_zone_write_plugging(struct bio *bio)
534 {
535 	return false;
536 }
537 static inline bool blk_req_bio_is_zone_append(struct request *req,
538 					      struct bio *bio)
539 {
540 	return false;
541 }
542 static inline void blk_zone_write_plug_bio_merged(struct bio *bio)
543 {
544 }
545 static inline void blk_zone_write_plug_init_request(struct request *rq)
546 {
547 }
548 static inline void blk_zone_append_update_request_bio(struct request *rq,
549 						      struct bio *bio)
550 {
551 }
552 static inline void blk_zone_bio_endio(struct bio *bio)
553 {
554 }
555 static inline void blk_zone_finish_request(struct request *rq)
556 {
557 }
558 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
559 		unsigned int cmd, unsigned long arg)
560 {
561 	return -ENOTTY;
562 }
563 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
564 		blk_mode_t mode, unsigned int cmd, unsigned long arg)
565 {
566 	return -ENOTTY;
567 }
568 #endif /* CONFIG_BLK_DEV_ZONED */
569 
570 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
571 void bdev_add(struct block_device *bdev, dev_t dev);
572 void bdev_unhash(struct block_device *bdev);
573 void bdev_drop(struct block_device *bdev);
574 
575 int blk_alloc_ext_minor(void);
576 void blk_free_ext_minor(unsigned int minor);
577 #define ADDPART_FLAG_NONE	0
578 #define ADDPART_FLAG_RAID	1
579 #define ADDPART_FLAG_WHOLEDISK	2
580 #define ADDPART_FLAG_READONLY	4
581 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
582 		sector_t length);
583 int bdev_del_partition(struct gendisk *disk, int partno);
584 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
585 		sector_t length);
586 void drop_partition(struct block_device *part);
587 
588 void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
589 
590 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
591 		struct lock_class_key *lkclass);
592 
593 /*
594  * Clean up a page appropriately, where the page may be pinned, may have a
595  * ref taken on it or neither.
596  */
597 static inline void bio_release_page(struct bio *bio, struct page *page)
598 {
599 	if (bio_flagged(bio, BIO_PAGE_PINNED))
600 		unpin_user_page(page);
601 }
602 
603 struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id);
604 
605 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
606 
607 int disk_alloc_events(struct gendisk *disk);
608 void disk_add_events(struct gendisk *disk);
609 void disk_del_events(struct gendisk *disk);
610 void disk_release_events(struct gendisk *disk);
611 void disk_block_events(struct gendisk *disk);
612 void disk_unblock_events(struct gendisk *disk);
613 void disk_flush_events(struct gendisk *disk, unsigned int mask);
614 extern struct device_attribute dev_attr_events;
615 extern struct device_attribute dev_attr_events_async;
616 extern struct device_attribute dev_attr_events_poll_msecs;
617 
618 extern struct attribute_group blk_trace_attr_group;
619 
620 blk_mode_t file_to_blk_mode(struct file *file);
621 int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
622 		loff_t lstart, loff_t lend);
623 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
624 int blkdev_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags);
625 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
626 
627 extern const struct address_space_operations def_blk_aops;
628 
629 int disk_register_independent_access_ranges(struct gendisk *disk);
630 void disk_unregister_independent_access_ranges(struct gendisk *disk);
631 
632 int should_fail_bio(struct bio *bio);
633 #ifdef CONFIG_FAIL_MAKE_REQUEST
634 bool should_fail_request(struct block_device *part, unsigned int bytes);
635 #else /* CONFIG_FAIL_MAKE_REQUEST */
636 static inline bool should_fail_request(struct block_device *part,
637 					unsigned int bytes)
638 {
639 	return false;
640 }
641 #endif /* CONFIG_FAIL_MAKE_REQUEST */
642 
643 /*
644  * Optimized request reference counting. Ideally we'd make timeouts be more
645  * clever, as that's the only reason we need references at all... But until
646  * this happens, this is faster than using refcount_t. Also see:
647  *
648  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
649  */
650 #define req_ref_zero_or_close_to_overflow(req)	\
651 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
652 
653 static inline bool req_ref_inc_not_zero(struct request *req)
654 {
655 	return atomic_inc_not_zero(&req->ref);
656 }
657 
658 static inline bool req_ref_put_and_test(struct request *req)
659 {
660 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
661 	return atomic_dec_and_test(&req->ref);
662 }
663 
664 static inline void req_ref_set(struct request *req, int value)
665 {
666 	atomic_set(&req->ref, value);
667 }
668 
669 static inline int req_ref_read(struct request *req)
670 {
671 	return atomic_read(&req->ref);
672 }
673 
674 static inline u64 blk_time_get_ns(void)
675 {
676 	struct blk_plug *plug = current->plug;
677 
678 	if (!plug || !in_task())
679 		return ktime_get_ns();
680 
681 	/*
682 	 * 0 could very well be a valid time, but rather than flag "this is
683 	 * a valid timestamp" separately, just accept that we'll do an extra
684 	 * ktime_get_ns() if we just happen to get 0 as the current time.
685 	 */
686 	if (!plug->cur_ktime) {
687 		plug->cur_ktime = ktime_get_ns();
688 		current->flags |= PF_BLOCK_TS;
689 	}
690 	return plug->cur_ktime;
691 }
692 
693 static inline ktime_t blk_time_get(void)
694 {
695 	return ns_to_ktime(blk_time_get_ns());
696 }
697 
698 void bdev_release(struct file *bdev_file);
699 int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
700 	      const struct blk_holder_ops *hops, struct file *bdev_file);
701 int bdev_permission(dev_t dev, blk_mode_t mode, void *holder);
702 
703 void blk_integrity_generate(struct bio *bio);
704 void blk_integrity_verify_iter(struct bio *bio, struct bvec_iter *saved_iter);
705 void blk_integrity_prepare(struct request *rq);
706 void blk_integrity_complete(struct request *rq, unsigned int nr_bytes);
707 
708 #ifdef CONFIG_LOCKDEP
709 static inline void blk_freeze_acquire_lock(struct request_queue *q)
710 {
711 	if (!q->mq_freeze_disk_dead)
712 		rwsem_acquire(&q->io_lockdep_map, 0, 1, _RET_IP_);
713 	if (!q->mq_freeze_queue_dying)
714 		rwsem_acquire(&q->q_lockdep_map, 0, 1, _RET_IP_);
715 }
716 
717 static inline void blk_unfreeze_release_lock(struct request_queue *q)
718 {
719 	if (!q->mq_freeze_queue_dying)
720 		rwsem_release(&q->q_lockdep_map, _RET_IP_);
721 	if (!q->mq_freeze_disk_dead)
722 		rwsem_release(&q->io_lockdep_map, _RET_IP_);
723 }
724 #else
725 static inline void blk_freeze_acquire_lock(struct request_queue *q)
726 {
727 }
728 static inline void blk_unfreeze_release_lock(struct request_queue *q)
729 {
730 }
731 #endif
732 
733 #endif /* BLK_INTERNAL_H */
734