xref: /linux/block/blk.h (revision 06b0a4ad7162b9dd7e52dbec320ea9d080d9e551)
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 elevator_type;
15 
16 #define	BLK_DEV_MAX_SECTORS	(LLONG_MAX >> 9)
17 
18 /* Max future timer expiry for timeouts */
19 #define BLK_MAX_TIMEOUT		(5 * HZ)
20 
21 extern struct dentry *blk_debugfs_root;
22 
23 struct blk_flush_queue {
24 	spinlock_t		mq_flush_lock;
25 	unsigned int		flush_pending_idx:1;
26 	unsigned int		flush_running_idx:1;
27 	blk_status_t 		rq_status;
28 	unsigned long		flush_pending_since;
29 	struct list_head	flush_queue[2];
30 	unsigned long		flush_data_in_flight;
31 	struct request		*flush_rq;
32 };
33 
34 bool is_flush_rq(struct request *req);
35 
36 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
37 					      gfp_t flags);
38 void blk_free_flush_queue(struct blk_flush_queue *q);
39 
40 bool __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
41 bool blk_queue_start_drain(struct request_queue *q);
42 bool __blk_freeze_queue_start(struct request_queue *q,
43 			      struct task_struct *owner);
44 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
45 void submit_bio_noacct_nocheck(struct bio *bio);
46 void bio_await_chain(struct bio *bio);
47 
48 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
49 {
50 	rcu_read_lock();
51 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
52 		goto fail;
53 
54 	/*
55 	 * The code that increments the pm_only counter must ensure that the
56 	 * counter is globally visible before the queue is unfrozen.
57 	 */
58 	if (blk_queue_pm_only(q) &&
59 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
60 		goto fail_put;
61 
62 	rcu_read_unlock();
63 	return true;
64 
65 fail_put:
66 	blk_queue_exit(q);
67 fail:
68 	rcu_read_unlock();
69 	return false;
70 }
71 
72 static inline int bio_queue_enter(struct bio *bio)
73 {
74 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
75 
76 	if (blk_try_enter_queue(q, false)) {
77 		rwsem_acquire_read(&q->io_lockdep_map, 0, 0, _RET_IP_);
78 		rwsem_release(&q->io_lockdep_map, _RET_IP_);
79 		return 0;
80 	}
81 	return __bio_queue_enter(q, bio);
82 }
83 
84 static inline void blk_wait_io(struct completion *done)
85 {
86 	/* Prevent hang_check timer from firing at us during very long I/O */
87 	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
88 
89 	if (timeout)
90 		while (!wait_for_completion_io_timeout(done, timeout))
91 			;
92 	else
93 		wait_for_completion_io(done);
94 }
95 
96 #define BIO_INLINE_VECS 4
97 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
98 		gfp_t gfp_mask);
99 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
100 
101 bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
102 		struct page *page, unsigned len, unsigned offset,
103 		bool *same_page);
104 
105 static inline bool biovec_phys_mergeable(struct request_queue *q,
106 		struct bio_vec *vec1, struct bio_vec *vec2)
107 {
108 	unsigned long mask = queue_segment_boundary(q);
109 	phys_addr_t addr1 = bvec_phys(vec1);
110 	phys_addr_t addr2 = bvec_phys(vec2);
111 
112 	/*
113 	 * Merging adjacent physical pages may not work correctly under KMSAN
114 	 * if their metadata pages aren't adjacent. Just disable merging.
115 	 */
116 	if (IS_ENABLED(CONFIG_KMSAN))
117 		return false;
118 
119 	if (addr1 + vec1->bv_len != addr2)
120 		return false;
121 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
122 		return false;
123 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
124 		return false;
125 	return true;
126 }
127 
128 static inline bool __bvec_gap_to_prev(const struct queue_limits *lim,
129 		struct bio_vec *bprv, unsigned int offset)
130 {
131 	return (offset & lim->virt_boundary_mask) ||
132 		((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask);
133 }
134 
135 /*
136  * Check if adding a bio_vec after bprv with offset would create a gap in
137  * the SG list. Most drivers don't care about this, but some do.
138  */
139 static inline bool bvec_gap_to_prev(const struct queue_limits *lim,
140 		struct bio_vec *bprv, unsigned int offset)
141 {
142 	if (!lim->virt_boundary_mask)
143 		return false;
144 	return __bvec_gap_to_prev(lim, bprv, offset);
145 }
146 
147 static inline bool rq_mergeable(struct request *rq)
148 {
149 	if (blk_rq_is_passthrough(rq))
150 		return false;
151 
152 	if (req_op(rq) == REQ_OP_FLUSH)
153 		return false;
154 
155 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
156 		return false;
157 
158 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
159 		return false;
160 
161 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
162 		return false;
163 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
164 		return false;
165 
166 	return true;
167 }
168 
169 /*
170  * There are two different ways to handle DISCARD merges:
171  *  1) If max_discard_segments > 1, the driver treats every bio as a range and
172  *     send the bios to controller together. The ranges don't need to be
173  *     contiguous.
174  *  2) Otherwise, the request will be normal read/write requests.  The ranges
175  *     need to be contiguous.
176  */
177 static inline bool blk_discard_mergable(struct request *req)
178 {
179 	if (req_op(req) == REQ_OP_DISCARD &&
180 	    queue_max_discard_segments(req->q) > 1)
181 		return true;
182 	return false;
183 }
184 
185 static inline unsigned int blk_rq_get_max_segments(struct request *rq)
186 {
187 	if (req_op(rq) == REQ_OP_DISCARD)
188 		return queue_max_discard_segments(rq->q);
189 	return queue_max_segments(rq->q);
190 }
191 
192 static inline unsigned int blk_queue_get_max_sectors(struct request *rq)
193 {
194 	struct request_queue *q = rq->q;
195 	enum req_op op = req_op(rq);
196 
197 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
198 		return min(q->limits.max_discard_sectors,
199 			   UINT_MAX >> SECTOR_SHIFT);
200 
201 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
202 		return q->limits.max_write_zeroes_sectors;
203 
204 	if (rq->cmd_flags & REQ_ATOMIC)
205 		return q->limits.atomic_write_max_sectors;
206 
207 	return q->limits.max_sectors;
208 }
209 
210 #ifdef CONFIG_BLK_DEV_INTEGRITY
211 void blk_flush_integrity(void);
212 void bio_integrity_free(struct bio *bio);
213 
214 /*
215  * Integrity payloads can either be owned by the submitter, in which case
216  * bio_uninit will free them, or owned and generated by the block layer,
217  * in which case we'll verify them here (for reads) and free them before
218  * the bio is handed back to the submitted.
219  */
220 bool __bio_integrity_endio(struct bio *bio);
221 static inline bool bio_integrity_endio(struct bio *bio)
222 {
223 	struct bio_integrity_payload *bip = bio_integrity(bio);
224 
225 	if (bip && (bip->bip_flags & BIP_BLOCK_INTEGRITY))
226 		return __bio_integrity_endio(bio);
227 	return true;
228 }
229 
230 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
231 		struct request *);
232 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
233 		struct bio *);
234 
235 static inline bool integrity_req_gap_back_merge(struct request *req,
236 		struct bio *next)
237 {
238 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
239 	struct bio_integrity_payload *bip_next = bio_integrity(next);
240 
241 	return bvec_gap_to_prev(&req->q->limits,
242 				&bip->bip_vec[bip->bip_vcnt - 1],
243 				bip_next->bip_vec[0].bv_offset);
244 }
245 
246 static inline bool integrity_req_gap_front_merge(struct request *req,
247 		struct bio *bio)
248 {
249 	struct bio_integrity_payload *bip = bio_integrity(bio);
250 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
251 
252 	return bvec_gap_to_prev(&req->q->limits,
253 				&bip->bip_vec[bip->bip_vcnt - 1],
254 				bip_next->bip_vec[0].bv_offset);
255 }
256 
257 extern const struct attribute_group blk_integrity_attr_group;
258 #else /* CONFIG_BLK_DEV_INTEGRITY */
259 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
260 		struct request *r1, struct request *r2)
261 {
262 	return true;
263 }
264 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
265 		struct request *r, struct bio *b)
266 {
267 	return true;
268 }
269 static inline bool integrity_req_gap_back_merge(struct request *req,
270 		struct bio *next)
271 {
272 	return false;
273 }
274 static inline bool integrity_req_gap_front_merge(struct request *req,
275 		struct bio *bio)
276 {
277 	return false;
278 }
279 
280 static inline void blk_flush_integrity(void)
281 {
282 }
283 static inline bool bio_integrity_endio(struct bio *bio)
284 {
285 	return true;
286 }
287 static inline void bio_integrity_free(struct bio *bio)
288 {
289 }
290 #endif /* CONFIG_BLK_DEV_INTEGRITY */
291 
292 unsigned long blk_rq_timeout(unsigned long timeout);
293 void blk_add_timer(struct request *req);
294 
295 enum bio_merge_status {
296 	BIO_MERGE_OK,
297 	BIO_MERGE_NONE,
298 	BIO_MERGE_FAILED,
299 };
300 
301 enum bio_merge_status bio_attempt_back_merge(struct request *req,
302 		struct bio *bio, unsigned int nr_segs);
303 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
304 		unsigned int nr_segs);
305 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
306 			struct bio *bio, unsigned int nr_segs);
307 
308 /*
309  * Plug flush limits
310  */
311 #define BLK_MAX_REQUEST_COUNT	32
312 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
313 
314 /*
315  * Internal elevator interface
316  */
317 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
318 
319 bool blk_insert_flush(struct request *rq);
320 
321 int elevator_switch(struct request_queue *q, struct elevator_type *new_e);
322 void elevator_disable(struct request_queue *q);
323 void elevator_exit(struct request_queue *q);
324 int elv_register_queue(struct request_queue *q, bool uevent);
325 void elv_unregister_queue(struct request_queue *q);
326 
327 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
328 		char *buf);
329 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
330 		char *buf);
331 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
332 		char *buf);
333 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
334 		char *buf);
335 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
336 		const char *buf, size_t count);
337 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
338 ssize_t part_timeout_store(struct device *, struct device_attribute *,
339 				const char *, size_t);
340 
341 struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,
342 		unsigned *nsegs);
343 struct bio *bio_split_write_zeroes(struct bio *bio,
344 		const struct queue_limits *lim, unsigned *nsegs);
345 struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
346 		unsigned *nr_segs);
347 struct bio *bio_split_zone_append(struct bio *bio,
348 		const struct queue_limits *lim, unsigned *nr_segs);
349 
350 /*
351  * All drivers must accept single-segments bios that are smaller than PAGE_SIZE.
352  *
353  * This is a quick and dirty check that relies on the fact that bi_io_vec[0] is
354  * always valid if a bio has data.  The check might lead to occasional false
355  * positives when bios are cloned, but compared to the performance impact of
356  * cloned bios themselves the loop below doesn't matter anyway.
357  */
358 static inline bool bio_may_need_split(struct bio *bio,
359 		const struct queue_limits *lim)
360 {
361 	return lim->chunk_sectors || bio->bi_vcnt != 1 ||
362 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
363 }
364 
365 /**
366  * __bio_split_to_limits - split a bio to fit the queue limits
367  * @bio:     bio to be split
368  * @lim:     queue limits to split based on
369  * @nr_segs: returns the number of segments in the returned bio
370  *
371  * Check if @bio needs splitting based on the queue limits, and if so split off
372  * a bio fitting the limits from the beginning of @bio and return it.  @bio is
373  * shortened to the remainder and re-submitted.
374  *
375  * The split bio is allocated from @q->bio_split, which is provided by the
376  * block layer.
377  */
378 static inline struct bio *__bio_split_to_limits(struct bio *bio,
379 		const struct queue_limits *lim, unsigned int *nr_segs)
380 {
381 	switch (bio_op(bio)) {
382 	case REQ_OP_READ:
383 	case REQ_OP_WRITE:
384 		if (bio_may_need_split(bio, lim))
385 			return bio_split_rw(bio, lim, nr_segs);
386 		*nr_segs = 1;
387 		return bio;
388 	case REQ_OP_ZONE_APPEND:
389 		return bio_split_zone_append(bio, lim, nr_segs);
390 	case REQ_OP_DISCARD:
391 	case REQ_OP_SECURE_ERASE:
392 		return bio_split_discard(bio, lim, nr_segs);
393 	case REQ_OP_WRITE_ZEROES:
394 		return bio_split_write_zeroes(bio, lim, nr_segs);
395 	default:
396 		/* other operations can't be split */
397 		*nr_segs = 0;
398 		return bio;
399 	}
400 }
401 
402 int ll_back_merge_fn(struct request *req, struct bio *bio,
403 		unsigned int nr_segs);
404 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
405 				struct request *next);
406 unsigned int blk_recalc_rq_segments(struct request *rq);
407 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
408 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
409 
410 int blk_set_default_limits(struct queue_limits *lim);
411 void blk_apply_bdi_limits(struct backing_dev_info *bdi,
412 		struct queue_limits *lim);
413 int blk_dev_init(void);
414 
415 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
416 unsigned int part_in_flight(struct block_device *part);
417 
418 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
419 {
420 	req->cmd_flags |= REQ_NOMERGE;
421 	if (req == q->last_merge)
422 		q->last_merge = NULL;
423 }
424 
425 /*
426  * Internal io_context interface
427  */
428 struct io_cq *ioc_find_get_icq(struct request_queue *q);
429 struct io_cq *ioc_lookup_icq(struct request_queue *q);
430 #ifdef CONFIG_BLK_ICQ
431 void ioc_clear_queue(struct request_queue *q);
432 #else
433 static inline void ioc_clear_queue(struct request_queue *q)
434 {
435 }
436 #endif /* CONFIG_BLK_ICQ */
437 
438 struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q);
439 
440 static inline bool blk_queue_may_bounce(struct request_queue *q)
441 {
442 	return IS_ENABLED(CONFIG_BOUNCE) &&
443 		(q->limits.features & BLK_FEAT_BOUNCE_HIGH) &&
444 		max_low_pfn >= max_pfn;
445 }
446 
447 static inline struct bio *blk_queue_bounce(struct bio *bio,
448 		struct request_queue *q)
449 {
450 	if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio)))
451 		return __blk_queue_bounce(bio, q);
452 	return bio;
453 }
454 
455 #ifdef CONFIG_BLK_DEV_ZONED
456 void disk_init_zone_resources(struct gendisk *disk);
457 void disk_free_zone_resources(struct gendisk *disk);
458 static inline bool bio_zone_write_plugging(struct bio *bio)
459 {
460 	return bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING);
461 }
462 void blk_zone_write_plug_bio_merged(struct bio *bio);
463 void blk_zone_write_plug_init_request(struct request *rq);
464 static inline void blk_zone_update_request_bio(struct request *rq,
465 					       struct bio *bio)
466 {
467 	/*
468 	 * For zone append requests, the request sector indicates the location
469 	 * at which the BIO data was written. Return this value to the BIO
470 	 * issuer through the BIO iter sector.
471 	 * For plugged zone writes, which include emulated zone append, we need
472 	 * the original BIO sector so that blk_zone_write_plug_bio_endio() can
473 	 * lookup the zone write plug.
474 	 */
475 	if (req_op(rq) == REQ_OP_ZONE_APPEND || bio_zone_write_plugging(bio))
476 		bio->bi_iter.bi_sector = rq->__sector;
477 }
478 void blk_zone_write_plug_bio_endio(struct bio *bio);
479 static inline void blk_zone_bio_endio(struct bio *bio)
480 {
481 	/*
482 	 * For write BIOs to zoned devices, signal the completion of the BIO so
483 	 * that the next write BIO can be submitted by zone write plugging.
484 	 */
485 	if (bio_zone_write_plugging(bio))
486 		blk_zone_write_plug_bio_endio(bio);
487 }
488 
489 void blk_zone_write_plug_finish_request(struct request *rq);
490 static inline void blk_zone_finish_request(struct request *rq)
491 {
492 	if (rq->rq_flags & RQF_ZONE_WRITE_PLUGGING)
493 		blk_zone_write_plug_finish_request(rq);
494 }
495 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
496 		unsigned long arg);
497 int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
498 		unsigned int cmd, unsigned long arg);
499 #else /* CONFIG_BLK_DEV_ZONED */
500 static inline void disk_init_zone_resources(struct gendisk *disk)
501 {
502 }
503 static inline void disk_free_zone_resources(struct gendisk *disk)
504 {
505 }
506 static inline bool bio_zone_write_plugging(struct bio *bio)
507 {
508 	return false;
509 }
510 static inline void blk_zone_write_plug_bio_merged(struct bio *bio)
511 {
512 }
513 static inline void blk_zone_write_plug_init_request(struct request *rq)
514 {
515 }
516 static inline void blk_zone_update_request_bio(struct request *rq,
517 					       struct bio *bio)
518 {
519 }
520 static inline void blk_zone_bio_endio(struct bio *bio)
521 {
522 }
523 static inline void blk_zone_finish_request(struct request *rq)
524 {
525 }
526 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
527 		unsigned int cmd, unsigned long arg)
528 {
529 	return -ENOTTY;
530 }
531 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
532 		blk_mode_t mode, unsigned int cmd, unsigned long arg)
533 {
534 	return -ENOTTY;
535 }
536 #endif /* CONFIG_BLK_DEV_ZONED */
537 
538 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
539 void bdev_add(struct block_device *bdev, dev_t dev);
540 void bdev_unhash(struct block_device *bdev);
541 void bdev_drop(struct block_device *bdev);
542 
543 int blk_alloc_ext_minor(void);
544 void blk_free_ext_minor(unsigned int minor);
545 #define ADDPART_FLAG_NONE	0
546 #define ADDPART_FLAG_RAID	1
547 #define ADDPART_FLAG_WHOLEDISK	2
548 #define ADDPART_FLAG_READONLY	4
549 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
550 		sector_t length);
551 int bdev_del_partition(struct gendisk *disk, int partno);
552 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
553 		sector_t length);
554 void drop_partition(struct block_device *part);
555 
556 void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
557 
558 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
559 		struct lock_class_key *lkclass);
560 
561 /*
562  * Clean up a page appropriately, where the page may be pinned, may have a
563  * ref taken on it or neither.
564  */
565 static inline void bio_release_page(struct bio *bio, struct page *page)
566 {
567 	if (bio_flagged(bio, BIO_PAGE_PINNED))
568 		unpin_user_page(page);
569 }
570 
571 struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id);
572 
573 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
574 
575 int disk_alloc_events(struct gendisk *disk);
576 void disk_add_events(struct gendisk *disk);
577 void disk_del_events(struct gendisk *disk);
578 void disk_release_events(struct gendisk *disk);
579 void disk_block_events(struct gendisk *disk);
580 void disk_unblock_events(struct gendisk *disk);
581 void disk_flush_events(struct gendisk *disk, unsigned int mask);
582 extern struct device_attribute dev_attr_events;
583 extern struct device_attribute dev_attr_events_async;
584 extern struct device_attribute dev_attr_events_poll_msecs;
585 
586 extern struct attribute_group blk_trace_attr_group;
587 
588 blk_mode_t file_to_blk_mode(struct file *file);
589 int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
590 		loff_t lstart, loff_t lend);
591 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
592 int blkdev_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags);
593 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
594 
595 extern const struct address_space_operations def_blk_aops;
596 
597 int disk_register_independent_access_ranges(struct gendisk *disk);
598 void disk_unregister_independent_access_ranges(struct gendisk *disk);
599 
600 #ifdef CONFIG_FAIL_MAKE_REQUEST
601 bool should_fail_request(struct block_device *part, unsigned int bytes);
602 #else /* CONFIG_FAIL_MAKE_REQUEST */
603 static inline bool should_fail_request(struct block_device *part,
604 					unsigned int bytes)
605 {
606 	return false;
607 }
608 #endif /* CONFIG_FAIL_MAKE_REQUEST */
609 
610 /*
611  * Optimized request reference counting. Ideally we'd make timeouts be more
612  * clever, as that's the only reason we need references at all... But until
613  * this happens, this is faster than using refcount_t. Also see:
614  *
615  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
616  */
617 #define req_ref_zero_or_close_to_overflow(req)	\
618 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
619 
620 static inline bool req_ref_inc_not_zero(struct request *req)
621 {
622 	return atomic_inc_not_zero(&req->ref);
623 }
624 
625 static inline bool req_ref_put_and_test(struct request *req)
626 {
627 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
628 	return atomic_dec_and_test(&req->ref);
629 }
630 
631 static inline void req_ref_set(struct request *req, int value)
632 {
633 	atomic_set(&req->ref, value);
634 }
635 
636 static inline int req_ref_read(struct request *req)
637 {
638 	return atomic_read(&req->ref);
639 }
640 
641 static inline u64 blk_time_get_ns(void)
642 {
643 	struct blk_plug *plug = current->plug;
644 
645 	if (!plug || !in_task())
646 		return ktime_get_ns();
647 
648 	/*
649 	 * 0 could very well be a valid time, but rather than flag "this is
650 	 * a valid timestamp" separately, just accept that we'll do an extra
651 	 * ktime_get_ns() if we just happen to get 0 as the current time.
652 	 */
653 	if (!plug->cur_ktime) {
654 		plug->cur_ktime = ktime_get_ns();
655 		current->flags |= PF_BLOCK_TS;
656 	}
657 	return plug->cur_ktime;
658 }
659 
660 static inline ktime_t blk_time_get(void)
661 {
662 	return ns_to_ktime(blk_time_get_ns());
663 }
664 
665 /*
666  * From most significant bit:
667  * 1 bit: reserved for other usage, see below
668  * 12 bits: original size of bio
669  * 51 bits: issue time of bio
670  */
671 #define BIO_ISSUE_RES_BITS      1
672 #define BIO_ISSUE_SIZE_BITS     12
673 #define BIO_ISSUE_RES_SHIFT     (64 - BIO_ISSUE_RES_BITS)
674 #define BIO_ISSUE_SIZE_SHIFT    (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
675 #define BIO_ISSUE_TIME_MASK     ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
676 #define BIO_ISSUE_SIZE_MASK     \
677 	(((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
678 #define BIO_ISSUE_RES_MASK      (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
679 
680 /* Reserved bit for blk-throtl */
681 #define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
682 
683 static inline u64 __bio_issue_time(u64 time)
684 {
685 	return time & BIO_ISSUE_TIME_MASK;
686 }
687 
688 static inline u64 bio_issue_time(struct bio_issue *issue)
689 {
690 	return __bio_issue_time(issue->value);
691 }
692 
693 static inline sector_t bio_issue_size(struct bio_issue *issue)
694 {
695 	return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
696 }
697 
698 static inline void bio_issue_init(struct bio_issue *issue,
699 				       sector_t size)
700 {
701 	size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
702 	issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
703 			(blk_time_get_ns() & BIO_ISSUE_TIME_MASK) |
704 			((u64)size << BIO_ISSUE_SIZE_SHIFT));
705 }
706 
707 void bdev_release(struct file *bdev_file);
708 int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
709 	      const struct blk_holder_ops *hops, struct file *bdev_file);
710 int bdev_permission(dev_t dev, blk_mode_t mode, void *holder);
711 
712 void blk_integrity_generate(struct bio *bio);
713 void blk_integrity_verify(struct bio *bio);
714 void blk_integrity_prepare(struct request *rq);
715 void blk_integrity_complete(struct request *rq, unsigned int nr_bytes);
716 
717 #ifdef CONFIG_LOCKDEP
718 static inline void blk_freeze_acquire_lock(struct request_queue *q)
719 {
720 	if (!q->mq_freeze_disk_dead)
721 		rwsem_acquire(&q->io_lockdep_map, 0, 1, _RET_IP_);
722 	if (!q->mq_freeze_queue_dying)
723 		rwsem_acquire(&q->q_lockdep_map, 0, 1, _RET_IP_);
724 }
725 
726 static inline void blk_unfreeze_release_lock(struct request_queue *q)
727 {
728 	if (!q->mq_freeze_queue_dying)
729 		rwsem_release(&q->q_lockdep_map, _RET_IP_);
730 	if (!q->mq_freeze_disk_dead)
731 		rwsem_release(&q->io_lockdep_map, _RET_IP_);
732 }
733 #else
734 static inline void blk_freeze_acquire_lock(struct request_queue *q)
735 {
736 }
737 static inline void blk_unfreeze_release_lock(struct request_queue *q)
738 {
739 }
740 #endif
741 
742 #endif /* BLK_INTERNAL_H */
743