xref: /linux/block/blk.h (revision daa121128a2d2ac6006159e2c47676e4fcd21eab)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef BLK_INTERNAL_H
3 #define BLK_INTERNAL_H
4 
5 #include <linux/blk-crypto.h>
6 #include <linux/memblock.h>	/* for max_pfn/max_low_pfn */
7 #include <linux/sched/sysctl.h>
8 #include <linux/timekeeping.h>
9 #include <xen/xen.h>
10 #include "blk-crypto-internal.h"
11 
12 struct elevator_type;
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 	spinlock_t		mq_flush_lock;
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 	unsigned long		flush_data_in_flight;
27 	struct request		*flush_rq;
28 };
29 
30 bool is_flush_rq(struct request *req);
31 
32 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
33 					      gfp_t flags);
34 void blk_free_flush_queue(struct blk_flush_queue *q);
35 
36 void blk_freeze_queue(struct request_queue *q);
37 void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
38 void blk_queue_start_drain(struct request_queue *q);
39 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
40 void submit_bio_noacct_nocheck(struct bio *bio);
41 void bio_await_chain(struct bio *bio);
42 
43 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
44 {
45 	rcu_read_lock();
46 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
47 		goto fail;
48 
49 	/*
50 	 * The code that increments the pm_only counter must ensure that the
51 	 * counter is globally visible before the queue is unfrozen.
52 	 */
53 	if (blk_queue_pm_only(q) &&
54 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
55 		goto fail_put;
56 
57 	rcu_read_unlock();
58 	return true;
59 
60 fail_put:
61 	blk_queue_exit(q);
62 fail:
63 	rcu_read_unlock();
64 	return false;
65 }
66 
67 static inline int bio_queue_enter(struct bio *bio)
68 {
69 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
70 
71 	if (blk_try_enter_queue(q, false))
72 		return 0;
73 	return __bio_queue_enter(q, bio);
74 }
75 
76 static inline void blk_wait_io(struct completion *done)
77 {
78 	/* Prevent hang_check timer from firing at us during very long I/O */
79 	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
80 
81 	if (timeout)
82 		while (!wait_for_completion_io_timeout(done, timeout))
83 			;
84 	else
85 		wait_for_completion_io(done);
86 }
87 
88 #define BIO_INLINE_VECS 4
89 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
90 		gfp_t gfp_mask);
91 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
92 
93 bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
94 		struct page *page, unsigned len, unsigned offset,
95 		bool *same_page);
96 
97 static inline bool biovec_phys_mergeable(struct request_queue *q,
98 		struct bio_vec *vec1, struct bio_vec *vec2)
99 {
100 	unsigned long mask = queue_segment_boundary(q);
101 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
102 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
103 
104 	/*
105 	 * Merging adjacent physical pages may not work correctly under KMSAN
106 	 * if their metadata pages aren't adjacent. Just disable merging.
107 	 */
108 	if (IS_ENABLED(CONFIG_KMSAN))
109 		return false;
110 
111 	if (addr1 + vec1->bv_len != addr2)
112 		return false;
113 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
114 		return false;
115 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
116 		return false;
117 	return true;
118 }
119 
120 static inline bool __bvec_gap_to_prev(const struct queue_limits *lim,
121 		struct bio_vec *bprv, unsigned int offset)
122 {
123 	return (offset & lim->virt_boundary_mask) ||
124 		((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask);
125 }
126 
127 /*
128  * Check if adding a bio_vec after bprv with offset would create a gap in
129  * the SG list. Most drivers don't care about this, but some do.
130  */
131 static inline bool bvec_gap_to_prev(const struct queue_limits *lim,
132 		struct bio_vec *bprv, unsigned int offset)
133 {
134 	if (!lim->virt_boundary_mask)
135 		return false;
136 	return __bvec_gap_to_prev(lim, bprv, offset);
137 }
138 
139 static inline bool rq_mergeable(struct request *rq)
140 {
141 	if (blk_rq_is_passthrough(rq))
142 		return false;
143 
144 	if (req_op(rq) == REQ_OP_FLUSH)
145 		return false;
146 
147 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
148 		return false;
149 
150 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
151 		return false;
152 
153 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
154 		return false;
155 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
156 		return false;
157 
158 	return true;
159 }
160 
161 /*
162  * There are two different ways to handle DISCARD merges:
163  *  1) If max_discard_segments > 1, the driver treats every bio as a range and
164  *     send the bios to controller together. The ranges don't need to be
165  *     contiguous.
166  *  2) Otherwise, the request will be normal read/write requests.  The ranges
167  *     need to be contiguous.
168  */
169 static inline bool blk_discard_mergable(struct request *req)
170 {
171 	if (req_op(req) == REQ_OP_DISCARD &&
172 	    queue_max_discard_segments(req->q) > 1)
173 		return true;
174 	return false;
175 }
176 
177 static inline unsigned int blk_rq_get_max_segments(struct request *rq)
178 {
179 	if (req_op(rq) == REQ_OP_DISCARD)
180 		return queue_max_discard_segments(rq->q);
181 	return queue_max_segments(rq->q);
182 }
183 
184 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
185 						     enum req_op op)
186 {
187 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
188 		return min(q->limits.max_discard_sectors,
189 			   UINT_MAX >> SECTOR_SHIFT);
190 
191 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
192 		return q->limits.max_write_zeroes_sectors;
193 
194 	return q->limits.max_sectors;
195 }
196 
197 #ifdef CONFIG_BLK_DEV_INTEGRITY
198 void blk_flush_integrity(void);
199 bool __bio_integrity_endio(struct bio *);
200 void bio_integrity_free(struct bio *bio);
201 static inline bool bio_integrity_endio(struct bio *bio)
202 {
203 	if (bio_integrity(bio))
204 		return __bio_integrity_endio(bio);
205 	return true;
206 }
207 
208 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
209 		struct request *);
210 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
211 		struct bio *);
212 
213 static inline bool integrity_req_gap_back_merge(struct request *req,
214 		struct bio *next)
215 {
216 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
217 	struct bio_integrity_payload *bip_next = bio_integrity(next);
218 
219 	return bvec_gap_to_prev(&req->q->limits,
220 				&bip->bip_vec[bip->bip_vcnt - 1],
221 				bip_next->bip_vec[0].bv_offset);
222 }
223 
224 static inline bool integrity_req_gap_front_merge(struct request *req,
225 		struct bio *bio)
226 {
227 	struct bio_integrity_payload *bip = bio_integrity(bio);
228 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
229 
230 	return bvec_gap_to_prev(&req->q->limits,
231 				&bip->bip_vec[bip->bip_vcnt - 1],
232 				bip_next->bip_vec[0].bv_offset);
233 }
234 
235 extern const struct attribute_group blk_integrity_attr_group;
236 #else /* CONFIG_BLK_DEV_INTEGRITY */
237 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
238 		struct request *r1, struct request *r2)
239 {
240 	return true;
241 }
242 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
243 		struct request *r, struct bio *b)
244 {
245 	return true;
246 }
247 static inline bool integrity_req_gap_back_merge(struct request *req,
248 		struct bio *next)
249 {
250 	return false;
251 }
252 static inline bool integrity_req_gap_front_merge(struct request *req,
253 		struct bio *bio)
254 {
255 	return false;
256 }
257 
258 static inline void blk_flush_integrity(void)
259 {
260 }
261 static inline bool bio_integrity_endio(struct bio *bio)
262 {
263 	return true;
264 }
265 static inline void bio_integrity_free(struct bio *bio)
266 {
267 }
268 #endif /* CONFIG_BLK_DEV_INTEGRITY */
269 
270 unsigned long blk_rq_timeout(unsigned long timeout);
271 void blk_add_timer(struct request *req);
272 
273 enum bio_merge_status {
274 	BIO_MERGE_OK,
275 	BIO_MERGE_NONE,
276 	BIO_MERGE_FAILED,
277 };
278 
279 enum bio_merge_status bio_attempt_back_merge(struct request *req,
280 		struct bio *bio, unsigned int nr_segs);
281 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
282 		unsigned int nr_segs);
283 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
284 			struct bio *bio, unsigned int nr_segs);
285 
286 /*
287  * Plug flush limits
288  */
289 #define BLK_MAX_REQUEST_COUNT	32
290 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
291 
292 /*
293  * Internal elevator interface
294  */
295 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
296 
297 bool blk_insert_flush(struct request *rq);
298 
299 int elevator_switch(struct request_queue *q, struct elevator_type *new_e);
300 void elevator_disable(struct request_queue *q);
301 void elevator_exit(struct request_queue *q);
302 int elv_register_queue(struct request_queue *q, bool uevent);
303 void elv_unregister_queue(struct request_queue *q);
304 
305 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
306 		char *buf);
307 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
308 		char *buf);
309 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
310 		char *buf);
311 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
312 		char *buf);
313 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
314 		const char *buf, size_t count);
315 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
316 ssize_t part_timeout_store(struct device *, struct device_attribute *,
317 				const char *, size_t);
318 
319 static inline bool bio_may_exceed_limits(struct bio *bio,
320 					 const struct queue_limits *lim)
321 {
322 	switch (bio_op(bio)) {
323 	case REQ_OP_DISCARD:
324 	case REQ_OP_SECURE_ERASE:
325 	case REQ_OP_WRITE_ZEROES:
326 		return true; /* non-trivial splitting decisions */
327 	default:
328 		break;
329 	}
330 
331 	/*
332 	 * All drivers must accept single-segments bios that are <= PAGE_SIZE.
333 	 * This is a quick and dirty check that relies on the fact that
334 	 * bi_io_vec[0] is always valid if a bio has data.  The check might
335 	 * lead to occasional false negatives when bios are cloned, but compared
336 	 * to the performance impact of cloned bios themselves the loop below
337 	 * doesn't matter anyway.
338 	 */
339 	return lim->chunk_sectors || bio->bi_vcnt != 1 ||
340 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
341 }
342 
343 struct bio *__bio_split_to_limits(struct bio *bio,
344 				  const struct queue_limits *lim,
345 				  unsigned int *nr_segs);
346 int ll_back_merge_fn(struct request *req, struct bio *bio,
347 		unsigned int nr_segs);
348 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
349 				struct request *next);
350 unsigned int blk_recalc_rq_segments(struct request *rq);
351 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
352 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
353 
354 int blk_set_default_limits(struct queue_limits *lim);
355 int blk_dev_init(void);
356 
357 /*
358  * Contribute to IO statistics IFF:
359  *
360  *	a) it's attached to a gendisk, and
361  *	b) the queue had IO stats enabled when this request was started
362  */
363 static inline bool blk_do_io_stat(struct request *rq)
364 {
365 	return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
366 }
367 
368 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
369 unsigned int part_in_flight(struct block_device *part);
370 
371 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
372 {
373 	req->cmd_flags |= REQ_NOMERGE;
374 	if (req == q->last_merge)
375 		q->last_merge = NULL;
376 }
377 
378 /*
379  * Internal io_context interface
380  */
381 struct io_cq *ioc_find_get_icq(struct request_queue *q);
382 struct io_cq *ioc_lookup_icq(struct request_queue *q);
383 #ifdef CONFIG_BLK_ICQ
384 void ioc_clear_queue(struct request_queue *q);
385 #else
386 static inline void ioc_clear_queue(struct request_queue *q)
387 {
388 }
389 #endif /* CONFIG_BLK_ICQ */
390 
391 struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q);
392 
393 static inline bool blk_queue_may_bounce(struct request_queue *q)
394 {
395 	return IS_ENABLED(CONFIG_BOUNCE) &&
396 		q->limits.bounce == BLK_BOUNCE_HIGH &&
397 		max_low_pfn >= max_pfn;
398 }
399 
400 static inline struct bio *blk_queue_bounce(struct bio *bio,
401 		struct request_queue *q)
402 {
403 	if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio)))
404 		return __blk_queue_bounce(bio, q);
405 	return bio;
406 }
407 
408 #ifdef CONFIG_BLK_DEV_ZONED
409 void disk_init_zone_resources(struct gendisk *disk);
410 void disk_free_zone_resources(struct gendisk *disk);
411 static inline bool bio_zone_write_plugging(struct bio *bio)
412 {
413 	return bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING);
414 }
415 static inline bool bio_is_zone_append(struct bio *bio)
416 {
417 	return bio_op(bio) == REQ_OP_ZONE_APPEND ||
418 		bio_flagged(bio, BIO_EMULATES_ZONE_APPEND);
419 }
420 void blk_zone_write_plug_bio_merged(struct bio *bio);
421 void blk_zone_write_plug_init_request(struct request *rq);
422 static inline void blk_zone_update_request_bio(struct request *rq,
423 					       struct bio *bio)
424 {
425 	/*
426 	 * For zone append requests, the request sector indicates the location
427 	 * at which the BIO data was written. Return this value to the BIO
428 	 * issuer through the BIO iter sector.
429 	 * For plugged zone writes, which include emulated zone append, we need
430 	 * the original BIO sector so that blk_zone_write_plug_bio_endio() can
431 	 * lookup the zone write plug.
432 	 */
433 	if (req_op(rq) == REQ_OP_ZONE_APPEND || bio_zone_write_plugging(bio))
434 		bio->bi_iter.bi_sector = rq->__sector;
435 }
436 void blk_zone_write_plug_bio_endio(struct bio *bio);
437 static inline void blk_zone_bio_endio(struct bio *bio)
438 {
439 	/*
440 	 * For write BIOs to zoned devices, signal the completion of the BIO so
441 	 * that the next write BIO can be submitted by zone write plugging.
442 	 */
443 	if (bio_zone_write_plugging(bio))
444 		blk_zone_write_plug_bio_endio(bio);
445 }
446 
447 void blk_zone_write_plug_finish_request(struct request *rq);
448 static inline void blk_zone_finish_request(struct request *rq)
449 {
450 	if (rq->rq_flags & RQF_ZONE_WRITE_PLUGGING)
451 		blk_zone_write_plug_finish_request(rq);
452 }
453 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
454 		unsigned long arg);
455 int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
456 		unsigned int cmd, unsigned long arg);
457 #else /* CONFIG_BLK_DEV_ZONED */
458 static inline void disk_init_zone_resources(struct gendisk *disk)
459 {
460 }
461 static inline void disk_free_zone_resources(struct gendisk *disk)
462 {
463 }
464 static inline bool bio_zone_write_plugging(struct bio *bio)
465 {
466 	return false;
467 }
468 static inline bool bio_is_zone_append(struct bio *bio)
469 {
470 	return false;
471 }
472 static inline void blk_zone_write_plug_bio_merged(struct bio *bio)
473 {
474 }
475 static inline void blk_zone_write_plug_init_request(struct request *rq)
476 {
477 }
478 static inline void blk_zone_update_request_bio(struct request *rq,
479 					       struct bio *bio)
480 {
481 }
482 static inline void blk_zone_bio_endio(struct bio *bio)
483 {
484 }
485 static inline void blk_zone_finish_request(struct request *rq)
486 {
487 }
488 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
489 		unsigned int cmd, unsigned long arg)
490 {
491 	return -ENOTTY;
492 }
493 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
494 		blk_mode_t mode, unsigned int cmd, unsigned long arg)
495 {
496 	return -ENOTTY;
497 }
498 #endif /* CONFIG_BLK_DEV_ZONED */
499 
500 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
501 void bdev_add(struct block_device *bdev, dev_t dev);
502 
503 int blk_alloc_ext_minor(void);
504 void blk_free_ext_minor(unsigned int minor);
505 #define ADDPART_FLAG_NONE	0
506 #define ADDPART_FLAG_RAID	1
507 #define ADDPART_FLAG_WHOLEDISK	2
508 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
509 		sector_t length);
510 int bdev_del_partition(struct gendisk *disk, int partno);
511 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
512 		sector_t length);
513 void drop_partition(struct block_device *part);
514 
515 void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
516 
517 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
518 		struct lock_class_key *lkclass);
519 
520 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
521 		struct page *page, unsigned int len, unsigned int offset,
522 		unsigned int max_sectors, bool *same_page);
523 
524 /*
525  * Clean up a page appropriately, where the page may be pinned, may have a
526  * ref taken on it or neither.
527  */
528 static inline void bio_release_page(struct bio *bio, struct page *page)
529 {
530 	if (bio_flagged(bio, BIO_PAGE_PINNED))
531 		unpin_user_page(page);
532 }
533 
534 struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id);
535 
536 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
537 
538 int disk_alloc_events(struct gendisk *disk);
539 void disk_add_events(struct gendisk *disk);
540 void disk_del_events(struct gendisk *disk);
541 void disk_release_events(struct gendisk *disk);
542 void disk_block_events(struct gendisk *disk);
543 void disk_unblock_events(struct gendisk *disk);
544 void disk_flush_events(struct gendisk *disk, unsigned int mask);
545 extern struct device_attribute dev_attr_events;
546 extern struct device_attribute dev_attr_events_async;
547 extern struct device_attribute dev_attr_events_poll_msecs;
548 
549 extern struct attribute_group blk_trace_attr_group;
550 
551 blk_mode_t file_to_blk_mode(struct file *file);
552 int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
553 		loff_t lstart, loff_t lend);
554 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
555 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
556 
557 extern const struct address_space_operations def_blk_aops;
558 
559 int disk_register_independent_access_ranges(struct gendisk *disk);
560 void disk_unregister_independent_access_ranges(struct gendisk *disk);
561 
562 #ifdef CONFIG_FAIL_MAKE_REQUEST
563 bool should_fail_request(struct block_device *part, unsigned int bytes);
564 #else /* CONFIG_FAIL_MAKE_REQUEST */
565 static inline bool should_fail_request(struct block_device *part,
566 					unsigned int bytes)
567 {
568 	return false;
569 }
570 #endif /* CONFIG_FAIL_MAKE_REQUEST */
571 
572 /*
573  * Optimized request reference counting. Ideally we'd make timeouts be more
574  * clever, as that's the only reason we need references at all... But until
575  * this happens, this is faster than using refcount_t. Also see:
576  *
577  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
578  */
579 #define req_ref_zero_or_close_to_overflow(req)	\
580 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
581 
582 static inline bool req_ref_inc_not_zero(struct request *req)
583 {
584 	return atomic_inc_not_zero(&req->ref);
585 }
586 
587 static inline bool req_ref_put_and_test(struct request *req)
588 {
589 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
590 	return atomic_dec_and_test(&req->ref);
591 }
592 
593 static inline void req_ref_set(struct request *req, int value)
594 {
595 	atomic_set(&req->ref, value);
596 }
597 
598 static inline int req_ref_read(struct request *req)
599 {
600 	return atomic_read(&req->ref);
601 }
602 
603 static inline u64 blk_time_get_ns(void)
604 {
605 	struct blk_plug *plug = current->plug;
606 
607 	if (!plug || !in_task())
608 		return ktime_get_ns();
609 
610 	/*
611 	 * 0 could very well be a valid time, but rather than flag "this is
612 	 * a valid timestamp" separately, just accept that we'll do an extra
613 	 * ktime_get_ns() if we just happen to get 0 as the current time.
614 	 */
615 	if (!plug->cur_ktime) {
616 		plug->cur_ktime = ktime_get_ns();
617 		current->flags |= PF_BLOCK_TS;
618 	}
619 	return plug->cur_ktime;
620 }
621 
622 static inline ktime_t blk_time_get(void)
623 {
624 	return ns_to_ktime(blk_time_get_ns());
625 }
626 
627 /*
628  * From most significant bit:
629  * 1 bit: reserved for other usage, see below
630  * 12 bits: original size of bio
631  * 51 bits: issue time of bio
632  */
633 #define BIO_ISSUE_RES_BITS      1
634 #define BIO_ISSUE_SIZE_BITS     12
635 #define BIO_ISSUE_RES_SHIFT     (64 - BIO_ISSUE_RES_BITS)
636 #define BIO_ISSUE_SIZE_SHIFT    (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
637 #define BIO_ISSUE_TIME_MASK     ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
638 #define BIO_ISSUE_SIZE_MASK     \
639 	(((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
640 #define BIO_ISSUE_RES_MASK      (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
641 
642 /* Reserved bit for blk-throtl */
643 #define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
644 
645 static inline u64 __bio_issue_time(u64 time)
646 {
647 	return time & BIO_ISSUE_TIME_MASK;
648 }
649 
650 static inline u64 bio_issue_time(struct bio_issue *issue)
651 {
652 	return __bio_issue_time(issue->value);
653 }
654 
655 static inline sector_t bio_issue_size(struct bio_issue *issue)
656 {
657 	return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
658 }
659 
660 static inline void bio_issue_init(struct bio_issue *issue,
661 				       sector_t size)
662 {
663 	size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
664 	issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
665 			(blk_time_get_ns() & BIO_ISSUE_TIME_MASK) |
666 			((u64)size << BIO_ISSUE_SIZE_SHIFT));
667 }
668 
669 void bdev_release(struct file *bdev_file);
670 int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
671 	      const struct blk_holder_ops *hops, struct file *bdev_file);
672 int bdev_permission(dev_t dev, blk_mode_t mode, void *holder);
673 
674 #endif /* BLK_INTERNAL_H */
675