xref: /linux/block/blk.h (revision 46e6acfe3501fa938af9c5bd730f0020235b08a2)
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/memblock.h>	/* for max_pfn/max_low_pfn */
8 #include <linux/sched/sysctl.h>
9 #include <linux/timekeeping.h>
10 #include <xen/xen.h>
11 #include "blk-crypto-internal.h"
12 
13 struct elevator_type;
14 
15 /* Max future timer expiry for timeouts */
16 #define BLK_MAX_TIMEOUT		(5 * HZ)
17 
18 extern struct dentry *blk_debugfs_root;
19 
20 struct blk_flush_queue {
21 	spinlock_t		mq_flush_lock;
22 	unsigned int		flush_pending_idx:1;
23 	unsigned int		flush_running_idx:1;
24 	blk_status_t 		rq_status;
25 	unsigned long		flush_pending_since;
26 	struct list_head	flush_queue[2];
27 	unsigned long		flush_data_in_flight;
28 	struct request		*flush_rq;
29 };
30 
31 bool is_flush_rq(struct request *req);
32 
33 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
34 					      gfp_t flags);
35 void blk_free_flush_queue(struct blk_flush_queue *q);
36 
37 void blk_freeze_queue(struct request_queue *q);
38 void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
39 void blk_queue_start_drain(struct request_queue *q);
40 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
41 void submit_bio_noacct_nocheck(struct bio *bio);
42 void bio_await_chain(struct bio *bio);
43 
44 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
45 {
46 	rcu_read_lock();
47 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
48 		goto fail;
49 
50 	/*
51 	 * The code that increments the pm_only counter must ensure that the
52 	 * counter is globally visible before the queue is unfrozen.
53 	 */
54 	if (blk_queue_pm_only(q) &&
55 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
56 		goto fail_put;
57 
58 	rcu_read_unlock();
59 	return true;
60 
61 fail_put:
62 	blk_queue_exit(q);
63 fail:
64 	rcu_read_unlock();
65 	return false;
66 }
67 
68 static inline int bio_queue_enter(struct bio *bio)
69 {
70 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
71 
72 	if (blk_try_enter_queue(q, false))
73 		return 0;
74 	return __bio_queue_enter(q, bio);
75 }
76 
77 static inline void blk_wait_io(struct completion *done)
78 {
79 	/* Prevent hang_check timer from firing at us during very long I/O */
80 	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
81 
82 	if (timeout)
83 		while (!wait_for_completion_io_timeout(done, timeout))
84 			;
85 	else
86 		wait_for_completion_io(done);
87 }
88 
89 #define BIO_INLINE_VECS 4
90 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
91 		gfp_t gfp_mask);
92 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
93 
94 bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
95 		struct page *page, unsigned len, unsigned offset,
96 		bool *same_page);
97 
98 static inline bool biovec_phys_mergeable(struct request_queue *q,
99 		struct bio_vec *vec1, struct bio_vec *vec2)
100 {
101 	unsigned long mask = queue_segment_boundary(q);
102 	phys_addr_t addr1 = bvec_phys(vec1);
103 	phys_addr_t addr2 = bvec_phys(vec2);
104 
105 	/*
106 	 * Merging adjacent physical pages may not work correctly under KMSAN
107 	 * if their metadata pages aren't adjacent. Just disable merging.
108 	 */
109 	if (IS_ENABLED(CONFIG_KMSAN))
110 		return false;
111 
112 	if (addr1 + vec1->bv_len != addr2)
113 		return false;
114 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
115 		return false;
116 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
117 		return false;
118 	return true;
119 }
120 
121 static inline bool __bvec_gap_to_prev(const struct queue_limits *lim,
122 		struct bio_vec *bprv, unsigned int offset)
123 {
124 	return (offset & lim->virt_boundary_mask) ||
125 		((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask);
126 }
127 
128 /*
129  * Check if adding a bio_vec after bprv with offset would create a gap in
130  * the SG list. Most drivers don't care about this, but some do.
131  */
132 static inline bool bvec_gap_to_prev(const struct queue_limits *lim,
133 		struct bio_vec *bprv, unsigned int offset)
134 {
135 	if (!lim->virt_boundary_mask)
136 		return false;
137 	return __bvec_gap_to_prev(lim, bprv, offset);
138 }
139 
140 static inline bool rq_mergeable(struct request *rq)
141 {
142 	if (blk_rq_is_passthrough(rq))
143 		return false;
144 
145 	if (req_op(rq) == REQ_OP_FLUSH)
146 		return false;
147 
148 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
149 		return false;
150 
151 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
152 		return false;
153 
154 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
155 		return false;
156 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
157 		return false;
158 
159 	return true;
160 }
161 
162 /*
163  * There are two different ways to handle DISCARD merges:
164  *  1) If max_discard_segments > 1, the driver treats every bio as a range and
165  *     send the bios to controller together. The ranges don't need to be
166  *     contiguous.
167  *  2) Otherwise, the request will be normal read/write requests.  The ranges
168  *     need to be contiguous.
169  */
170 static inline bool blk_discard_mergable(struct request *req)
171 {
172 	if (req_op(req) == REQ_OP_DISCARD &&
173 	    queue_max_discard_segments(req->q) > 1)
174 		return true;
175 	return false;
176 }
177 
178 static inline unsigned int blk_rq_get_max_segments(struct request *rq)
179 {
180 	if (req_op(rq) == REQ_OP_DISCARD)
181 		return queue_max_discard_segments(rq->q);
182 	return queue_max_segments(rq->q);
183 }
184 
185 static inline unsigned int blk_queue_get_max_sectors(struct request *rq)
186 {
187 	struct request_queue *q = rq->q;
188 	enum req_op op = req_op(rq);
189 
190 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
191 		return min(q->limits.max_discard_sectors,
192 			   UINT_MAX >> SECTOR_SHIFT);
193 
194 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
195 		return q->limits.max_write_zeroes_sectors;
196 
197 	if (rq->cmd_flags & REQ_ATOMIC)
198 		return q->limits.atomic_write_max_sectors;
199 
200 	return q->limits.max_sectors;
201 }
202 
203 #ifdef CONFIG_BLK_DEV_INTEGRITY
204 void blk_flush_integrity(void);
205 void bio_integrity_free(struct bio *bio);
206 
207 /*
208  * Integrity payloads can either be owned by the submitter, in which case
209  * bio_uninit will free them, or owned and generated by the block layer,
210  * in which case we'll verify them here (for reads) and free them before
211  * the bio is handed back to the submitted.
212  */
213 bool __bio_integrity_endio(struct bio *bio);
214 static inline bool bio_integrity_endio(struct bio *bio)
215 {
216 	struct bio_integrity_payload *bip = bio_integrity(bio);
217 
218 	if (bip && (bip->bip_flags & BIP_BLOCK_INTEGRITY))
219 		return __bio_integrity_endio(bio);
220 	return true;
221 }
222 
223 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
224 		struct request *);
225 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
226 		struct bio *);
227 
228 static inline bool integrity_req_gap_back_merge(struct request *req,
229 		struct bio *next)
230 {
231 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
232 	struct bio_integrity_payload *bip_next = bio_integrity(next);
233 
234 	return bvec_gap_to_prev(&req->q->limits,
235 				&bip->bip_vec[bip->bip_vcnt - 1],
236 				bip_next->bip_vec[0].bv_offset);
237 }
238 
239 static inline bool integrity_req_gap_front_merge(struct request *req,
240 		struct bio *bio)
241 {
242 	struct bio_integrity_payload *bip = bio_integrity(bio);
243 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
244 
245 	return bvec_gap_to_prev(&req->q->limits,
246 				&bip->bip_vec[bip->bip_vcnt - 1],
247 				bip_next->bip_vec[0].bv_offset);
248 }
249 
250 extern const struct attribute_group blk_integrity_attr_group;
251 #else /* CONFIG_BLK_DEV_INTEGRITY */
252 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
253 		struct request *r1, struct request *r2)
254 {
255 	return true;
256 }
257 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
258 		struct request *r, struct bio *b)
259 {
260 	return true;
261 }
262 static inline bool integrity_req_gap_back_merge(struct request *req,
263 		struct bio *next)
264 {
265 	return false;
266 }
267 static inline bool integrity_req_gap_front_merge(struct request *req,
268 		struct bio *bio)
269 {
270 	return false;
271 }
272 
273 static inline void blk_flush_integrity(void)
274 {
275 }
276 static inline bool bio_integrity_endio(struct bio *bio)
277 {
278 	return true;
279 }
280 static inline void bio_integrity_free(struct bio *bio)
281 {
282 }
283 #endif /* CONFIG_BLK_DEV_INTEGRITY */
284 
285 unsigned long blk_rq_timeout(unsigned long timeout);
286 void blk_add_timer(struct request *req);
287 
288 enum bio_merge_status {
289 	BIO_MERGE_OK,
290 	BIO_MERGE_NONE,
291 	BIO_MERGE_FAILED,
292 };
293 
294 enum bio_merge_status bio_attempt_back_merge(struct request *req,
295 		struct bio *bio, unsigned int nr_segs);
296 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
297 		unsigned int nr_segs);
298 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
299 			struct bio *bio, unsigned int nr_segs);
300 
301 /*
302  * Plug flush limits
303  */
304 #define BLK_MAX_REQUEST_COUNT	32
305 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
306 
307 /*
308  * Internal elevator interface
309  */
310 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
311 
312 bool blk_insert_flush(struct request *rq);
313 
314 int elevator_switch(struct request_queue *q, struct elevator_type *new_e);
315 void elevator_disable(struct request_queue *q);
316 void elevator_exit(struct request_queue *q);
317 int elv_register_queue(struct request_queue *q, bool uevent);
318 void elv_unregister_queue(struct request_queue *q);
319 
320 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
321 		char *buf);
322 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
323 		char *buf);
324 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
325 		char *buf);
326 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
327 		char *buf);
328 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
329 		const char *buf, size_t count);
330 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
331 ssize_t part_timeout_store(struct device *, struct device_attribute *,
332 				const char *, size_t);
333 
334 static inline bool bio_may_exceed_limits(struct bio *bio,
335 					 const struct queue_limits *lim)
336 {
337 	switch (bio_op(bio)) {
338 	case REQ_OP_DISCARD:
339 	case REQ_OP_SECURE_ERASE:
340 	case REQ_OP_WRITE_ZEROES:
341 		return true; /* non-trivial splitting decisions */
342 	default:
343 		break;
344 	}
345 
346 	/*
347 	 * All drivers must accept single-segments bios that are <= PAGE_SIZE.
348 	 * This is a quick and dirty check that relies on the fact that
349 	 * bi_io_vec[0] is always valid if a bio has data.  The check might
350 	 * lead to occasional false negatives when bios are cloned, but compared
351 	 * to the performance impact of cloned bios themselves the loop below
352 	 * doesn't matter anyway.
353 	 */
354 	return lim->chunk_sectors || bio->bi_vcnt != 1 ||
355 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
356 }
357 
358 struct bio *__bio_split_to_limits(struct bio *bio,
359 				  const struct queue_limits *lim,
360 				  unsigned int *nr_segs);
361 int ll_back_merge_fn(struct request *req, struct bio *bio,
362 		unsigned int nr_segs);
363 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
364 				struct request *next);
365 unsigned int blk_recalc_rq_segments(struct request *rq);
366 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
367 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
368 
369 int blk_set_default_limits(struct queue_limits *lim);
370 void blk_apply_bdi_limits(struct backing_dev_info *bdi,
371 		struct queue_limits *lim);
372 int blk_dev_init(void);
373 
374 /*
375  * Contribute to IO statistics IFF:
376  *
377  *	a) it's attached to a gendisk, and
378  *	b) the queue had IO stats enabled when this request was started
379  */
380 static inline bool blk_do_io_stat(struct request *rq)
381 {
382 	return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
383 }
384 
385 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
386 unsigned int part_in_flight(struct block_device *part);
387 
388 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
389 {
390 	req->cmd_flags |= REQ_NOMERGE;
391 	if (req == q->last_merge)
392 		q->last_merge = NULL;
393 }
394 
395 /*
396  * Internal io_context interface
397  */
398 struct io_cq *ioc_find_get_icq(struct request_queue *q);
399 struct io_cq *ioc_lookup_icq(struct request_queue *q);
400 #ifdef CONFIG_BLK_ICQ
401 void ioc_clear_queue(struct request_queue *q);
402 #else
403 static inline void ioc_clear_queue(struct request_queue *q)
404 {
405 }
406 #endif /* CONFIG_BLK_ICQ */
407 
408 struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q);
409 
410 static inline bool blk_queue_may_bounce(struct request_queue *q)
411 {
412 	return IS_ENABLED(CONFIG_BOUNCE) &&
413 		(q->limits.features & BLK_FEAT_BOUNCE_HIGH) &&
414 		max_low_pfn >= max_pfn;
415 }
416 
417 static inline struct bio *blk_queue_bounce(struct bio *bio,
418 		struct request_queue *q)
419 {
420 	if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio)))
421 		return __blk_queue_bounce(bio, q);
422 	return bio;
423 }
424 
425 #ifdef CONFIG_BLK_DEV_ZONED
426 void disk_init_zone_resources(struct gendisk *disk);
427 void disk_free_zone_resources(struct gendisk *disk);
428 static inline bool bio_zone_write_plugging(struct bio *bio)
429 {
430 	return bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING);
431 }
432 static inline bool bio_is_zone_append(struct bio *bio)
433 {
434 	return bio_op(bio) == REQ_OP_ZONE_APPEND ||
435 		bio_flagged(bio, BIO_EMULATES_ZONE_APPEND);
436 }
437 void blk_zone_write_plug_bio_merged(struct bio *bio);
438 void blk_zone_write_plug_init_request(struct request *rq);
439 static inline void blk_zone_update_request_bio(struct request *rq,
440 					       struct bio *bio)
441 {
442 	/*
443 	 * For zone append requests, the request sector indicates the location
444 	 * at which the BIO data was written. Return this value to the BIO
445 	 * issuer through the BIO iter sector.
446 	 * For plugged zone writes, which include emulated zone append, we need
447 	 * the original BIO sector so that blk_zone_write_plug_bio_endio() can
448 	 * lookup the zone write plug.
449 	 */
450 	if (req_op(rq) == REQ_OP_ZONE_APPEND || bio_zone_write_plugging(bio))
451 		bio->bi_iter.bi_sector = rq->__sector;
452 }
453 void blk_zone_write_plug_bio_endio(struct bio *bio);
454 static inline void blk_zone_bio_endio(struct bio *bio)
455 {
456 	/*
457 	 * For write BIOs to zoned devices, signal the completion of the BIO so
458 	 * that the next write BIO can be submitted by zone write plugging.
459 	 */
460 	if (bio_zone_write_plugging(bio))
461 		blk_zone_write_plug_bio_endio(bio);
462 }
463 
464 void blk_zone_write_plug_finish_request(struct request *rq);
465 static inline void blk_zone_finish_request(struct request *rq)
466 {
467 	if (rq->rq_flags & RQF_ZONE_WRITE_PLUGGING)
468 		blk_zone_write_plug_finish_request(rq);
469 }
470 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
471 		unsigned long arg);
472 int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
473 		unsigned int cmd, unsigned long arg);
474 #else /* CONFIG_BLK_DEV_ZONED */
475 static inline void disk_init_zone_resources(struct gendisk *disk)
476 {
477 }
478 static inline void disk_free_zone_resources(struct gendisk *disk)
479 {
480 }
481 static inline bool bio_zone_write_plugging(struct bio *bio)
482 {
483 	return false;
484 }
485 static inline bool bio_is_zone_append(struct bio *bio)
486 {
487 	return false;
488 }
489 static inline void blk_zone_write_plug_bio_merged(struct bio *bio)
490 {
491 }
492 static inline void blk_zone_write_plug_init_request(struct request *rq)
493 {
494 }
495 static inline void blk_zone_update_request_bio(struct request *rq,
496 					       struct bio *bio)
497 {
498 }
499 static inline void blk_zone_bio_endio(struct bio *bio)
500 {
501 }
502 static inline void blk_zone_finish_request(struct request *rq)
503 {
504 }
505 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
506 		unsigned int cmd, unsigned long arg)
507 {
508 	return -ENOTTY;
509 }
510 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
511 		blk_mode_t mode, unsigned int cmd, unsigned long arg)
512 {
513 	return -ENOTTY;
514 }
515 #endif /* CONFIG_BLK_DEV_ZONED */
516 
517 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
518 void bdev_add(struct block_device *bdev, dev_t dev);
519 void bdev_unhash(struct block_device *bdev);
520 void bdev_drop(struct block_device *bdev);
521 
522 int blk_alloc_ext_minor(void);
523 void blk_free_ext_minor(unsigned int minor);
524 #define ADDPART_FLAG_NONE	0
525 #define ADDPART_FLAG_RAID	1
526 #define ADDPART_FLAG_WHOLEDISK	2
527 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
528 		sector_t length);
529 int bdev_del_partition(struct gendisk *disk, int partno);
530 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
531 		sector_t length);
532 void drop_partition(struct block_device *part);
533 
534 void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
535 
536 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
537 		struct lock_class_key *lkclass);
538 
539 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
540 		struct page *page, unsigned int len, unsigned int offset,
541 		unsigned int max_sectors, bool *same_page);
542 
543 /*
544  * Clean up a page appropriately, where the page may be pinned, may have a
545  * ref taken on it or neither.
546  */
547 static inline void bio_release_page(struct bio *bio, struct page *page)
548 {
549 	if (bio_flagged(bio, BIO_PAGE_PINNED))
550 		unpin_user_page(page);
551 }
552 
553 struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id);
554 
555 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
556 
557 int disk_alloc_events(struct gendisk *disk);
558 void disk_add_events(struct gendisk *disk);
559 void disk_del_events(struct gendisk *disk);
560 void disk_release_events(struct gendisk *disk);
561 void disk_block_events(struct gendisk *disk);
562 void disk_unblock_events(struct gendisk *disk);
563 void disk_flush_events(struct gendisk *disk, unsigned int mask);
564 extern struct device_attribute dev_attr_events;
565 extern struct device_attribute dev_attr_events_async;
566 extern struct device_attribute dev_attr_events_poll_msecs;
567 
568 extern struct attribute_group blk_trace_attr_group;
569 
570 blk_mode_t file_to_blk_mode(struct file *file);
571 int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
572 		loff_t lstart, loff_t lend);
573 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
574 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
575 
576 extern const struct address_space_operations def_blk_aops;
577 
578 int disk_register_independent_access_ranges(struct gendisk *disk);
579 void disk_unregister_independent_access_ranges(struct gendisk *disk);
580 
581 #ifdef CONFIG_FAIL_MAKE_REQUEST
582 bool should_fail_request(struct block_device *part, unsigned int bytes);
583 #else /* CONFIG_FAIL_MAKE_REQUEST */
584 static inline bool should_fail_request(struct block_device *part,
585 					unsigned int bytes)
586 {
587 	return false;
588 }
589 #endif /* CONFIG_FAIL_MAKE_REQUEST */
590 
591 /*
592  * Optimized request reference counting. Ideally we'd make timeouts be more
593  * clever, as that's the only reason we need references at all... But until
594  * this happens, this is faster than using refcount_t. Also see:
595  *
596  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
597  */
598 #define req_ref_zero_or_close_to_overflow(req)	\
599 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
600 
601 static inline bool req_ref_inc_not_zero(struct request *req)
602 {
603 	return atomic_inc_not_zero(&req->ref);
604 }
605 
606 static inline bool req_ref_put_and_test(struct request *req)
607 {
608 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
609 	return atomic_dec_and_test(&req->ref);
610 }
611 
612 static inline void req_ref_set(struct request *req, int value)
613 {
614 	atomic_set(&req->ref, value);
615 }
616 
617 static inline int req_ref_read(struct request *req)
618 {
619 	return atomic_read(&req->ref);
620 }
621 
622 static inline u64 blk_time_get_ns(void)
623 {
624 	struct blk_plug *plug = current->plug;
625 
626 	if (!plug || !in_task())
627 		return ktime_get_ns();
628 
629 	/*
630 	 * 0 could very well be a valid time, but rather than flag "this is
631 	 * a valid timestamp" separately, just accept that we'll do an extra
632 	 * ktime_get_ns() if we just happen to get 0 as the current time.
633 	 */
634 	if (!plug->cur_ktime) {
635 		plug->cur_ktime = ktime_get_ns();
636 		current->flags |= PF_BLOCK_TS;
637 	}
638 	return plug->cur_ktime;
639 }
640 
641 static inline ktime_t blk_time_get(void)
642 {
643 	return ns_to_ktime(blk_time_get_ns());
644 }
645 
646 /*
647  * From most significant bit:
648  * 1 bit: reserved for other usage, see below
649  * 12 bits: original size of bio
650  * 51 bits: issue time of bio
651  */
652 #define BIO_ISSUE_RES_BITS      1
653 #define BIO_ISSUE_SIZE_BITS     12
654 #define BIO_ISSUE_RES_SHIFT     (64 - BIO_ISSUE_RES_BITS)
655 #define BIO_ISSUE_SIZE_SHIFT    (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
656 #define BIO_ISSUE_TIME_MASK     ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
657 #define BIO_ISSUE_SIZE_MASK     \
658 	(((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
659 #define BIO_ISSUE_RES_MASK      (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
660 
661 /* Reserved bit for blk-throtl */
662 #define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
663 
664 static inline u64 __bio_issue_time(u64 time)
665 {
666 	return time & BIO_ISSUE_TIME_MASK;
667 }
668 
669 static inline u64 bio_issue_time(struct bio_issue *issue)
670 {
671 	return __bio_issue_time(issue->value);
672 }
673 
674 static inline sector_t bio_issue_size(struct bio_issue *issue)
675 {
676 	return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
677 }
678 
679 static inline void bio_issue_init(struct bio_issue *issue,
680 				       sector_t size)
681 {
682 	size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
683 	issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
684 			(blk_time_get_ns() & BIO_ISSUE_TIME_MASK) |
685 			((u64)size << BIO_ISSUE_SIZE_SHIFT));
686 }
687 
688 void bdev_release(struct file *bdev_file);
689 int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
690 	      const struct blk_holder_ops *hops, struct file *bdev_file);
691 int bdev_permission(dev_t dev, blk_mode_t mode, void *holder);
692 
693 void blk_integrity_generate(struct bio *bio);
694 void blk_integrity_verify(struct bio *bio);
695 void blk_integrity_prepare(struct request *rq);
696 void blk_integrity_complete(struct request *rq, unsigned int nr_bytes);
697 
698 #endif /* BLK_INTERNAL_H */
699