xref: /linux-6.15/include/linux/blkdev.h (revision f1bc423f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BLKDEV_H
3 #define _LINUX_BLKDEV_H
4 
5 #include <linux/sched.h>
6 #include <linux/genhd.h>
7 #include <linux/list.h>
8 #include <linux/llist.h>
9 #include <linux/minmax.h>
10 #include <linux/timer.h>
11 #include <linux/workqueue.h>
12 #include <linux/wait.h>
13 #include <linux/bio.h>
14 #include <linux/gfp.h>
15 #include <linux/rcupdate.h>
16 #include <linux/percpu-refcount.h>
17 #include <linux/blkzoned.h>
18 #include <linux/sbitmap.h>
19 #include <linux/srcu.h>
20 
21 struct module;
22 struct request_queue;
23 struct elevator_queue;
24 struct blk_trace;
25 struct request;
26 struct sg_io_hdr;
27 struct blkcg_gq;
28 struct blk_flush_queue;
29 struct kiocb;
30 struct pr_ops;
31 struct rq_qos;
32 struct blk_queue_stats;
33 struct blk_stat_callback;
34 struct blk_crypto_profile;
35 
36 /* Must be consistent with blk_mq_poll_stats_bkt() */
37 #define BLK_MQ_POLL_STATS_BKTS 16
38 
39 /* Doing classic polling */
40 #define BLK_MQ_POLL_CLASSIC -1
41 
42 /*
43  * Maximum number of blkcg policies allowed to be registered concurrently.
44  * Defined here to simplify include dependency.
45  */
46 #define BLKCG_MAX_POLS		6
47 
48 static inline int blk_validate_block_size(unsigned long bsize)
49 {
50 	if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
51 		return -EINVAL;
52 
53 	return 0;
54 }
55 
56 static inline bool blk_op_is_passthrough(unsigned int op)
57 {
58 	op &= REQ_OP_MASK;
59 	return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
60 }
61 
62 /*
63  * Zoned block device models (zoned limit).
64  *
65  * Note: This needs to be ordered from the least to the most severe
66  * restrictions for the inheritance in blk_stack_limits() to work.
67  */
68 enum blk_zoned_model {
69 	BLK_ZONED_NONE = 0,	/* Regular block device */
70 	BLK_ZONED_HA,		/* Host-aware zoned block device */
71 	BLK_ZONED_HM,		/* Host-managed zoned block device */
72 };
73 
74 /*
75  * BLK_BOUNCE_NONE:	never bounce (default)
76  * BLK_BOUNCE_HIGH:	bounce all highmem pages
77  */
78 enum blk_bounce {
79 	BLK_BOUNCE_NONE,
80 	BLK_BOUNCE_HIGH,
81 };
82 
83 struct queue_limits {
84 	enum blk_bounce		bounce;
85 	unsigned long		seg_boundary_mask;
86 	unsigned long		virt_boundary_mask;
87 
88 	unsigned int		max_hw_sectors;
89 	unsigned int		max_dev_sectors;
90 	unsigned int		chunk_sectors;
91 	unsigned int		max_sectors;
92 	unsigned int		max_segment_size;
93 	unsigned int		physical_block_size;
94 	unsigned int		logical_block_size;
95 	unsigned int		alignment_offset;
96 	unsigned int		io_min;
97 	unsigned int		io_opt;
98 	unsigned int		max_discard_sectors;
99 	unsigned int		max_hw_discard_sectors;
100 	unsigned int		max_write_same_sectors;
101 	unsigned int		max_write_zeroes_sectors;
102 	unsigned int		max_zone_append_sectors;
103 	unsigned int		discard_granularity;
104 	unsigned int		discard_alignment;
105 	unsigned int		zone_write_granularity;
106 
107 	unsigned short		max_segments;
108 	unsigned short		max_integrity_segments;
109 	unsigned short		max_discard_segments;
110 
111 	unsigned char		misaligned;
112 	unsigned char		discard_misaligned;
113 	unsigned char		raid_partial_stripes_expensive;
114 	enum blk_zoned_model	zoned;
115 };
116 
117 typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,
118 			       void *data);
119 
120 void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model);
121 
122 #ifdef CONFIG_BLK_DEV_ZONED
123 
124 #define BLK_ALL_ZONES  ((unsigned int)-1)
125 int blkdev_report_zones(struct block_device *bdev, sector_t sector,
126 			unsigned int nr_zones, report_zones_cb cb, void *data);
127 unsigned int blkdev_nr_zones(struct gendisk *disk);
128 extern int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
129 			    sector_t sectors, sector_t nr_sectors,
130 			    gfp_t gfp_mask);
131 int blk_revalidate_disk_zones(struct gendisk *disk,
132 			      void (*update_driver_data)(struct gendisk *disk));
133 
134 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
135 				     unsigned int cmd, unsigned long arg);
136 extern int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
137 				  unsigned int cmd, unsigned long arg);
138 
139 #else /* CONFIG_BLK_DEV_ZONED */
140 
141 static inline unsigned int blkdev_nr_zones(struct gendisk *disk)
142 {
143 	return 0;
144 }
145 
146 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
147 					    fmode_t mode, unsigned int cmd,
148 					    unsigned long arg)
149 {
150 	return -ENOTTY;
151 }
152 
153 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
154 					 fmode_t mode, unsigned int cmd,
155 					 unsigned long arg)
156 {
157 	return -ENOTTY;
158 }
159 
160 #endif /* CONFIG_BLK_DEV_ZONED */
161 
162 /*
163  * Independent access ranges: struct blk_independent_access_range describes
164  * a range of contiguous sectors that can be accessed using device command
165  * execution resources that are independent from the resources used for
166  * other access ranges. This is typically found with single-LUN multi-actuator
167  * HDDs where each access range is served by a different set of heads.
168  * The set of independent ranges supported by the device is defined using
169  * struct blk_independent_access_ranges. The independent ranges must not overlap
170  * and must include all sectors within the disk capacity (no sector holes
171  * allowed).
172  * For a device with multiple ranges, requests targeting sectors in different
173  * ranges can be executed in parallel. A request can straddle an access range
174  * boundary.
175  */
176 struct blk_independent_access_range {
177 	struct kobject		kobj;
178 	struct request_queue	*queue;
179 	sector_t		sector;
180 	sector_t		nr_sectors;
181 };
182 
183 struct blk_independent_access_ranges {
184 	struct kobject				kobj;
185 	bool					sysfs_registered;
186 	unsigned int				nr_ia_ranges;
187 	struct blk_independent_access_range	ia_range[];
188 };
189 
190 struct request_queue {
191 	struct request		*last_merge;
192 	struct elevator_queue	*elevator;
193 
194 	struct percpu_ref	q_usage_counter;
195 
196 	struct blk_queue_stats	*stats;
197 	struct rq_qos		*rq_qos;
198 
199 	const struct blk_mq_ops	*mq_ops;
200 
201 	/* sw queues */
202 	struct blk_mq_ctx __percpu	*queue_ctx;
203 
204 	unsigned int		queue_depth;
205 
206 	/* hw dispatch queues */
207 	struct blk_mq_hw_ctx	**queue_hw_ctx;
208 	unsigned int		nr_hw_queues;
209 
210 	/*
211 	 * The queue owner gets to use this for whatever they like.
212 	 * ll_rw_blk doesn't touch it.
213 	 */
214 	void			*queuedata;
215 
216 	/*
217 	 * various queue flags, see QUEUE_* below
218 	 */
219 	unsigned long		queue_flags;
220 	/*
221 	 * Number of contexts that have called blk_set_pm_only(). If this
222 	 * counter is above zero then only RQF_PM requests are processed.
223 	 */
224 	atomic_t		pm_only;
225 
226 	/*
227 	 * ida allocated id for this queue.  Used to index queues from
228 	 * ioctx.
229 	 */
230 	int			id;
231 
232 	spinlock_t		queue_lock;
233 
234 	struct gendisk		*disk;
235 
236 	/*
237 	 * queue kobject
238 	 */
239 	struct kobject kobj;
240 
241 	/*
242 	 * mq queue kobject
243 	 */
244 	struct kobject *mq_kobj;
245 
246 #ifdef  CONFIG_BLK_DEV_INTEGRITY
247 	struct blk_integrity integrity;
248 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
249 
250 #ifdef CONFIG_PM
251 	struct device		*dev;
252 	enum rpm_status		rpm_status;
253 #endif
254 
255 	/*
256 	 * queue settings
257 	 */
258 	unsigned long		nr_requests;	/* Max # of requests */
259 
260 	unsigned int		dma_pad_mask;
261 	unsigned int		dma_alignment;
262 
263 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
264 	struct blk_crypto_profile *crypto_profile;
265 #endif
266 
267 	unsigned int		rq_timeout;
268 	int			poll_nsec;
269 
270 	struct blk_stat_callback	*poll_cb;
271 	struct blk_rq_stat	*poll_stat;
272 
273 	struct timer_list	timeout;
274 	struct work_struct	timeout_work;
275 
276 	atomic_t		nr_active_requests_shared_tags;
277 
278 	struct blk_mq_tags	*sched_shared_tags;
279 
280 	struct list_head	icq_list;
281 #ifdef CONFIG_BLK_CGROUP
282 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
283 	struct blkcg_gq		*root_blkg;
284 	struct list_head	blkg_list;
285 #endif
286 
287 	struct queue_limits	limits;
288 
289 	unsigned int		required_elevator_features;
290 
291 #ifdef CONFIG_BLK_DEV_ZONED
292 	/*
293 	 * Zoned block device information for request dispatch control.
294 	 * nr_zones is the total number of zones of the device. This is always
295 	 * 0 for regular block devices. conv_zones_bitmap is a bitmap of nr_zones
296 	 * bits which indicates if a zone is conventional (bit set) or
297 	 * sequential (bit clear). seq_zones_wlock is a bitmap of nr_zones
298 	 * bits which indicates if a zone is write locked, that is, if a write
299 	 * request targeting the zone was dispatched. All three fields are
300 	 * initialized by the low level device driver (e.g. scsi/sd.c).
301 	 * Stacking drivers (device mappers) may or may not initialize
302 	 * these fields.
303 	 *
304 	 * Reads of this information must be protected with blk_queue_enter() /
305 	 * blk_queue_exit(). Modifying this information is only allowed while
306 	 * no requests are being processed. See also blk_mq_freeze_queue() and
307 	 * blk_mq_unfreeze_queue().
308 	 */
309 	unsigned int		nr_zones;
310 	unsigned long		*conv_zones_bitmap;
311 	unsigned long		*seq_zones_wlock;
312 	unsigned int		max_open_zones;
313 	unsigned int		max_active_zones;
314 #endif /* CONFIG_BLK_DEV_ZONED */
315 
316 	int			node;
317 	struct mutex		debugfs_mutex;
318 #ifdef CONFIG_BLK_DEV_IO_TRACE
319 	struct blk_trace __rcu	*blk_trace;
320 #endif
321 	/*
322 	 * for flush operations
323 	 */
324 	struct blk_flush_queue	*fq;
325 
326 	struct list_head	requeue_list;
327 	spinlock_t		requeue_lock;
328 	struct delayed_work	requeue_work;
329 
330 	struct mutex		sysfs_lock;
331 	struct mutex		sysfs_dir_lock;
332 
333 	/*
334 	 * for reusing dead hctx instance in case of updating
335 	 * nr_hw_queues
336 	 */
337 	struct list_head	unused_hctx_list;
338 	spinlock_t		unused_hctx_lock;
339 
340 	int			mq_freeze_depth;
341 
342 #ifdef CONFIG_BLK_DEV_THROTTLING
343 	/* Throttle data */
344 	struct throtl_data *td;
345 #endif
346 	struct rcu_head		rcu_head;
347 	wait_queue_head_t	mq_freeze_wq;
348 	/*
349 	 * Protect concurrent access to q_usage_counter by
350 	 * percpu_ref_kill() and percpu_ref_reinit().
351 	 */
352 	struct mutex		mq_freeze_lock;
353 
354 	int			quiesce_depth;
355 
356 	struct blk_mq_tag_set	*tag_set;
357 	struct list_head	tag_set_list;
358 	struct bio_set		bio_split;
359 
360 	struct dentry		*debugfs_dir;
361 
362 #ifdef CONFIG_BLK_DEBUG_FS
363 	struct dentry		*sched_debugfs_dir;
364 	struct dentry		*rqos_debugfs_dir;
365 #endif
366 
367 	bool			mq_sysfs_init_done;
368 
369 #define BLK_MAX_WRITE_HINTS	5
370 	u64			write_hints[BLK_MAX_WRITE_HINTS];
371 
372 	/*
373 	 * Independent sector access ranges. This is always NULL for
374 	 * devices that do not have multiple independent access ranges.
375 	 */
376 	struct blk_independent_access_ranges *ia_ranges;
377 
378 	/**
379 	 * @srcu: Sleepable RCU. Use as lock when type of the request queue
380 	 * is blocking (BLK_MQ_F_BLOCKING). Must be the last member
381 	 */
382 	struct srcu_struct	srcu[];
383 };
384 
385 /* Keep blk_queue_flag_name[] in sync with the definitions below */
386 #define QUEUE_FLAG_STOPPED	0	/* queue is stopped */
387 #define QUEUE_FLAG_DYING	1	/* queue being torn down */
388 #define QUEUE_FLAG_HAS_SRCU	2	/* SRCU is allocated */
389 #define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
390 #define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
391 #define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
392 #define QUEUE_FLAG_NONROT	6	/* non-rotational device (SSD) */
393 #define QUEUE_FLAG_VIRT		QUEUE_FLAG_NONROT /* paravirt device */
394 #define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
395 #define QUEUE_FLAG_DISCARD	8	/* supports DISCARD */
396 #define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
397 #define QUEUE_FLAG_ADD_RANDOM	10	/* Contributes to random pool */
398 #define QUEUE_FLAG_SECERASE	11	/* supports secure erase */
399 #define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
400 #define QUEUE_FLAG_DEAD		13	/* queue tear-down finished */
401 #define QUEUE_FLAG_INIT_DONE	14	/* queue is initialized */
402 #define QUEUE_FLAG_STABLE_WRITES 15	/* don't modify blks until WB is done */
403 #define QUEUE_FLAG_POLL		16	/* IO polling enabled if set */
404 #define QUEUE_FLAG_WC		17	/* Write back caching */
405 #define QUEUE_FLAG_FUA		18	/* device supports FUA writes */
406 #define QUEUE_FLAG_DAX		19	/* device supports DAX */
407 #define QUEUE_FLAG_STATS	20	/* track IO start and completion times */
408 #define QUEUE_FLAG_REGISTERED	22	/* queue has been registered to a disk */
409 #define QUEUE_FLAG_QUIESCED	24	/* queue has been quiesced */
410 #define QUEUE_FLAG_PCI_P2PDMA	25	/* device supports PCI p2p requests */
411 #define QUEUE_FLAG_ZONE_RESETALL 26	/* supports Zone Reset All */
412 #define QUEUE_FLAG_RQ_ALLOC_TIME 27	/* record rq->alloc_time_ns */
413 #define QUEUE_FLAG_HCTX_ACTIVE	28	/* at least one blk-mq hctx is active */
414 #define QUEUE_FLAG_NOWAIT       29	/* device supports NOWAIT */
415 
416 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
417 				 (1 << QUEUE_FLAG_SAME_COMP) |		\
418 				 (1 << QUEUE_FLAG_NOWAIT))
419 
420 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
421 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
422 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
423 
424 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
425 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
426 #define blk_queue_has_srcu(q)	test_bit(QUEUE_FLAG_HAS_SRCU, &(q)->queue_flags)
427 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
428 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
429 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
430 #define blk_queue_noxmerges(q)	\
431 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
432 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
433 #define blk_queue_stable_writes(q) \
434 	test_bit(QUEUE_FLAG_STABLE_WRITES, &(q)->queue_flags)
435 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
436 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
437 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
438 #define blk_queue_zone_resetall(q)	\
439 	test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
440 #define blk_queue_secure_erase(q) \
441 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
442 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
443 #define blk_queue_pci_p2pdma(q)	\
444 	test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
445 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
446 #define blk_queue_rq_alloc_time(q)	\
447 	test_bit(QUEUE_FLAG_RQ_ALLOC_TIME, &(q)->queue_flags)
448 #else
449 #define blk_queue_rq_alloc_time(q)	false
450 #endif
451 
452 #define blk_noretry_request(rq) \
453 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
454 			     REQ_FAILFAST_DRIVER))
455 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
456 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
457 #define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
458 #define blk_queue_registered(q)	test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
459 #define blk_queue_nowait(q)	test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags)
460 
461 extern void blk_set_pm_only(struct request_queue *q);
462 extern void blk_clear_pm_only(struct request_queue *q);
463 
464 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
465 
466 #define dma_map_bvec(dev, bv, dir, attrs) \
467 	dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
468 	(dir), (attrs))
469 
470 static inline bool queue_is_mq(struct request_queue *q)
471 {
472 	return q->mq_ops;
473 }
474 
475 #ifdef CONFIG_PM
476 static inline enum rpm_status queue_rpm_status(struct request_queue *q)
477 {
478 	return q->rpm_status;
479 }
480 #else
481 static inline enum rpm_status queue_rpm_status(struct request_queue *q)
482 {
483 	return RPM_ACTIVE;
484 }
485 #endif
486 
487 static inline enum blk_zoned_model
488 blk_queue_zoned_model(struct request_queue *q)
489 {
490 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
491 		return q->limits.zoned;
492 	return BLK_ZONED_NONE;
493 }
494 
495 static inline bool blk_queue_is_zoned(struct request_queue *q)
496 {
497 	switch (blk_queue_zoned_model(q)) {
498 	case BLK_ZONED_HA:
499 	case BLK_ZONED_HM:
500 		return true;
501 	default:
502 		return false;
503 	}
504 }
505 
506 static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
507 {
508 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
509 }
510 
511 #ifdef CONFIG_BLK_DEV_ZONED
512 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
513 {
514 	return blk_queue_is_zoned(q) ? q->nr_zones : 0;
515 }
516 
517 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
518 					     sector_t sector)
519 {
520 	if (!blk_queue_is_zoned(q))
521 		return 0;
522 	return sector >> ilog2(q->limits.chunk_sectors);
523 }
524 
525 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
526 					 sector_t sector)
527 {
528 	if (!blk_queue_is_zoned(q))
529 		return false;
530 	if (!q->conv_zones_bitmap)
531 		return true;
532 	return !test_bit(blk_queue_zone_no(q, sector), q->conv_zones_bitmap);
533 }
534 
535 static inline void blk_queue_max_open_zones(struct request_queue *q,
536 		unsigned int max_open_zones)
537 {
538 	q->max_open_zones = max_open_zones;
539 }
540 
541 static inline unsigned int queue_max_open_zones(const struct request_queue *q)
542 {
543 	return q->max_open_zones;
544 }
545 
546 static inline void blk_queue_max_active_zones(struct request_queue *q,
547 		unsigned int max_active_zones)
548 {
549 	q->max_active_zones = max_active_zones;
550 }
551 
552 static inline unsigned int queue_max_active_zones(const struct request_queue *q)
553 {
554 	return q->max_active_zones;
555 }
556 #else /* CONFIG_BLK_DEV_ZONED */
557 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
558 {
559 	return 0;
560 }
561 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
562 					 sector_t sector)
563 {
564 	return false;
565 }
566 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
567 					     sector_t sector)
568 {
569 	return 0;
570 }
571 static inline unsigned int queue_max_open_zones(const struct request_queue *q)
572 {
573 	return 0;
574 }
575 static inline unsigned int queue_max_active_zones(const struct request_queue *q)
576 {
577 	return 0;
578 }
579 #endif /* CONFIG_BLK_DEV_ZONED */
580 
581 static inline unsigned int blk_queue_depth(struct request_queue *q)
582 {
583 	if (q->queue_depth)
584 		return q->queue_depth;
585 
586 	return q->nr_requests;
587 }
588 
589 /*
590  * default timeout for SG_IO if none specified
591  */
592 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
593 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
594 
595 /* This should not be used directly - use rq_for_each_segment */
596 #define for_each_bio(_bio)		\
597 	for (; _bio; _bio = _bio->bi_next)
598 
599 
600 extern int blk_register_queue(struct gendisk *disk);
601 extern void blk_unregister_queue(struct gendisk *disk);
602 void submit_bio_noacct(struct bio *bio);
603 
604 extern int blk_lld_busy(struct request_queue *q);
605 extern void blk_queue_split(struct bio **);
606 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
607 extern void blk_queue_exit(struct request_queue *q);
608 extern void blk_sync_queue(struct request_queue *q);
609 
610 /* Helper to convert REQ_OP_XXX to its string format XXX */
611 extern const char *blk_op_str(unsigned int op);
612 
613 int blk_status_to_errno(blk_status_t status);
614 blk_status_t errno_to_blk_status(int errno);
615 
616 /* only poll the hardware once, don't continue until a completion was found */
617 #define BLK_POLL_ONESHOT		(1 << 0)
618 /* do not sleep to wait for the expected completion time */
619 #define BLK_POLL_NOSLEEP		(1 << 1)
620 int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags);
621 int iocb_bio_iopoll(struct kiocb *kiocb, struct io_comp_batch *iob,
622 			unsigned int flags);
623 
624 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
625 {
626 	return bdev->bd_queue;	/* this is never NULL */
627 }
628 
629 #ifdef CONFIG_BLK_DEV_ZONED
630 
631 /* Helper to convert BLK_ZONE_ZONE_XXX to its string format XXX */
632 const char *blk_zone_cond_str(enum blk_zone_cond zone_cond);
633 
634 static inline unsigned int bio_zone_no(struct bio *bio)
635 {
636 	return blk_queue_zone_no(bdev_get_queue(bio->bi_bdev),
637 				 bio->bi_iter.bi_sector);
638 }
639 
640 static inline unsigned int bio_zone_is_seq(struct bio *bio)
641 {
642 	return blk_queue_zone_is_seq(bdev_get_queue(bio->bi_bdev),
643 				     bio->bi_iter.bi_sector);
644 }
645 #endif /* CONFIG_BLK_DEV_ZONED */
646 
647 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
648 						     int op)
649 {
650 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
651 		return min(q->limits.max_discard_sectors,
652 			   UINT_MAX >> SECTOR_SHIFT);
653 
654 	if (unlikely(op == REQ_OP_WRITE_SAME))
655 		return q->limits.max_write_same_sectors;
656 
657 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
658 		return q->limits.max_write_zeroes_sectors;
659 
660 	return q->limits.max_sectors;
661 }
662 
663 /*
664  * Return maximum size of a request at given offset. Only valid for
665  * file system requests.
666  */
667 static inline unsigned int blk_max_size_offset(struct request_queue *q,
668 					       sector_t offset,
669 					       unsigned int chunk_sectors)
670 {
671 	if (!chunk_sectors) {
672 		if (q->limits.chunk_sectors)
673 			chunk_sectors = q->limits.chunk_sectors;
674 		else
675 			return q->limits.max_sectors;
676 	}
677 
678 	if (likely(is_power_of_2(chunk_sectors)))
679 		chunk_sectors -= offset & (chunk_sectors - 1);
680 	else
681 		chunk_sectors -= sector_div(offset, chunk_sectors);
682 
683 	return min(q->limits.max_sectors, chunk_sectors);
684 }
685 
686 /*
687  * Access functions for manipulating queue properties
688  */
689 extern void blk_cleanup_queue(struct request_queue *);
690 void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce limit);
691 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
692 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
693 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
694 extern void blk_queue_max_discard_segments(struct request_queue *,
695 		unsigned short);
696 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
697 extern void blk_queue_max_discard_sectors(struct request_queue *q,
698 		unsigned int max_discard_sectors);
699 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
700 		unsigned int max_write_same_sectors);
701 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
702 		unsigned int max_write_same_sectors);
703 extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
704 extern void blk_queue_max_zone_append_sectors(struct request_queue *q,
705 		unsigned int max_zone_append_sectors);
706 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
707 void blk_queue_zone_write_granularity(struct request_queue *q,
708 				      unsigned int size);
709 extern void blk_queue_alignment_offset(struct request_queue *q,
710 				       unsigned int alignment);
711 void disk_update_readahead(struct gendisk *disk);
712 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
713 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
714 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
715 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
716 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
717 extern void blk_set_default_limits(struct queue_limits *lim);
718 extern void blk_set_stacking_limits(struct queue_limits *lim);
719 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
720 			    sector_t offset);
721 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
722 			      sector_t offset);
723 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
724 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
725 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
726 extern void blk_queue_dma_alignment(struct request_queue *, int);
727 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
728 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
729 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
730 
731 struct blk_independent_access_ranges *
732 disk_alloc_independent_access_ranges(struct gendisk *disk, int nr_ia_ranges);
733 void disk_set_independent_access_ranges(struct gendisk *disk,
734 				struct blk_independent_access_ranges *iars);
735 
736 /*
737  * Elevator features for blk_queue_required_elevator_features:
738  */
739 /* Supports zoned block devices sequential write constraint */
740 #define ELEVATOR_F_ZBD_SEQ_WRITE	(1U << 0)
741 /* Supports scheduling on multiple hardware queues */
742 #define ELEVATOR_F_MQ_AWARE		(1U << 1)
743 
744 extern void blk_queue_required_elevator_features(struct request_queue *q,
745 						 unsigned int features);
746 extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
747 					      struct device *dev);
748 
749 bool __must_check blk_get_queue(struct request_queue *);
750 extern void blk_put_queue(struct request_queue *);
751 
752 void blk_mark_disk_dead(struct gendisk *disk);
753 
754 #ifdef CONFIG_BLOCK
755 /*
756  * blk_plug permits building a queue of related requests by holding the I/O
757  * fragments for a short period. This allows merging of sequential requests
758  * into single larger request. As the requests are moved from a per-task list to
759  * the device's request_queue in a batch, this results in improved scalability
760  * as the lock contention for request_queue lock is reduced.
761  *
762  * It is ok not to disable preemption when adding the request to the plug list
763  * or when attempting a merge. For details, please see schedule() where
764  * blk_flush_plug() is called.
765  */
766 struct blk_plug {
767 	struct request *mq_list; /* blk-mq requests */
768 
769 	/* if ios_left is > 1, we can batch tag/rq allocations */
770 	struct request *cached_rq;
771 	unsigned short nr_ios;
772 
773 	unsigned short rq_count;
774 
775 	bool multiple_queues;
776 	bool has_elevator;
777 	bool nowait;
778 
779 	struct list_head cb_list; /* md requires an unplug callback */
780 };
781 
782 struct blk_plug_cb;
783 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
784 struct blk_plug_cb {
785 	struct list_head list;
786 	blk_plug_cb_fn callback;
787 	void *data;
788 };
789 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
790 					     void *data, int size);
791 extern void blk_start_plug(struct blk_plug *);
792 extern void blk_start_plug_nr_ios(struct blk_plug *, unsigned short);
793 extern void blk_finish_plug(struct blk_plug *);
794 
795 void blk_flush_plug(struct blk_plug *plug, bool from_schedule);
796 
797 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
798 {
799 	struct blk_plug *plug = tsk->plug;
800 
801 	return plug &&
802 		 (plug->mq_list || !list_empty(&plug->cb_list));
803 }
804 
805 int blkdev_issue_flush(struct block_device *bdev);
806 long nr_blockdev_pages(void);
807 #else /* CONFIG_BLOCK */
808 struct blk_plug {
809 };
810 
811 static inline void blk_start_plug_nr_ios(struct blk_plug *plug,
812 					 unsigned short nr_ios)
813 {
814 }
815 
816 static inline void blk_start_plug(struct blk_plug *plug)
817 {
818 }
819 
820 static inline void blk_finish_plug(struct blk_plug *plug)
821 {
822 }
823 
824 static inline void blk_flush_plug(struct blk_plug *plug, bool async)
825 {
826 }
827 
828 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
829 {
830 	return false;
831 }
832 
833 static inline int blkdev_issue_flush(struct block_device *bdev)
834 {
835 	return 0;
836 }
837 
838 static inline long nr_blockdev_pages(void)
839 {
840 	return 0;
841 }
842 #endif /* CONFIG_BLOCK */
843 
844 extern void blk_io_schedule(void);
845 
846 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
847 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
848 
849 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
850 
851 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
852 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
853 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
854 		sector_t nr_sects, gfp_t gfp_mask, int flags,
855 		struct bio **biop);
856 
857 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
858 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
859 
860 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
861 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
862 		unsigned flags);
863 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
864 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
865 
866 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
867 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
868 {
869 	return blkdev_issue_discard(sb->s_bdev,
870 				    block << (sb->s_blocksize_bits -
871 					      SECTOR_SHIFT),
872 				    nr_blocks << (sb->s_blocksize_bits -
873 						  SECTOR_SHIFT),
874 				    gfp_mask, flags);
875 }
876 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
877 		sector_t nr_blocks, gfp_t gfp_mask)
878 {
879 	return blkdev_issue_zeroout(sb->s_bdev,
880 				    block << (sb->s_blocksize_bits -
881 					      SECTOR_SHIFT),
882 				    nr_blocks << (sb->s_blocksize_bits -
883 						  SECTOR_SHIFT),
884 				    gfp_mask, 0);
885 }
886 
887 static inline bool bdev_is_partition(struct block_device *bdev)
888 {
889 	return bdev->bd_partno;
890 }
891 
892 enum blk_default_limits {
893 	BLK_MAX_SEGMENTS	= 128,
894 	BLK_SAFE_MAX_SECTORS	= 255,
895 	BLK_DEF_MAX_SECTORS	= 2560,
896 	BLK_MAX_SEGMENT_SIZE	= 65536,
897 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
898 };
899 
900 static inline unsigned long queue_segment_boundary(const struct request_queue *q)
901 {
902 	return q->limits.seg_boundary_mask;
903 }
904 
905 static inline unsigned long queue_virt_boundary(const struct request_queue *q)
906 {
907 	return q->limits.virt_boundary_mask;
908 }
909 
910 static inline unsigned int queue_max_sectors(const struct request_queue *q)
911 {
912 	return q->limits.max_sectors;
913 }
914 
915 static inline unsigned int queue_max_bytes(struct request_queue *q)
916 {
917 	return min_t(unsigned int, queue_max_sectors(q), INT_MAX >> 9) << 9;
918 }
919 
920 static inline unsigned int queue_max_hw_sectors(const struct request_queue *q)
921 {
922 	return q->limits.max_hw_sectors;
923 }
924 
925 static inline unsigned short queue_max_segments(const struct request_queue *q)
926 {
927 	return q->limits.max_segments;
928 }
929 
930 static inline unsigned short queue_max_discard_segments(const struct request_queue *q)
931 {
932 	return q->limits.max_discard_segments;
933 }
934 
935 static inline unsigned int queue_max_segment_size(const struct request_queue *q)
936 {
937 	return q->limits.max_segment_size;
938 }
939 
940 static inline unsigned int queue_max_zone_append_sectors(const struct request_queue *q)
941 {
942 
943 	const struct queue_limits *l = &q->limits;
944 
945 	return min(l->max_zone_append_sectors, l->max_sectors);
946 }
947 
948 static inline unsigned queue_logical_block_size(const struct request_queue *q)
949 {
950 	int retval = 512;
951 
952 	if (q && q->limits.logical_block_size)
953 		retval = q->limits.logical_block_size;
954 
955 	return retval;
956 }
957 
958 static inline unsigned int bdev_logical_block_size(struct block_device *bdev)
959 {
960 	return queue_logical_block_size(bdev_get_queue(bdev));
961 }
962 
963 static inline unsigned int queue_physical_block_size(const struct request_queue *q)
964 {
965 	return q->limits.physical_block_size;
966 }
967 
968 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
969 {
970 	return queue_physical_block_size(bdev_get_queue(bdev));
971 }
972 
973 static inline unsigned int queue_io_min(const struct request_queue *q)
974 {
975 	return q->limits.io_min;
976 }
977 
978 static inline int bdev_io_min(struct block_device *bdev)
979 {
980 	return queue_io_min(bdev_get_queue(bdev));
981 }
982 
983 static inline unsigned int queue_io_opt(const struct request_queue *q)
984 {
985 	return q->limits.io_opt;
986 }
987 
988 static inline int bdev_io_opt(struct block_device *bdev)
989 {
990 	return queue_io_opt(bdev_get_queue(bdev));
991 }
992 
993 static inline unsigned int
994 queue_zone_write_granularity(const struct request_queue *q)
995 {
996 	return q->limits.zone_write_granularity;
997 }
998 
999 static inline unsigned int
1000 bdev_zone_write_granularity(struct block_device *bdev)
1001 {
1002 	return queue_zone_write_granularity(bdev_get_queue(bdev));
1003 }
1004 
1005 static inline int queue_alignment_offset(const struct request_queue *q)
1006 {
1007 	if (q->limits.misaligned)
1008 		return -1;
1009 
1010 	return q->limits.alignment_offset;
1011 }
1012 
1013 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1014 {
1015 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1016 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1017 		<< SECTOR_SHIFT;
1018 
1019 	return (granularity + lim->alignment_offset - alignment) % granularity;
1020 }
1021 
1022 static inline int bdev_alignment_offset(struct block_device *bdev)
1023 {
1024 	struct request_queue *q = bdev_get_queue(bdev);
1025 
1026 	if (q->limits.misaligned)
1027 		return -1;
1028 	if (bdev_is_partition(bdev))
1029 		return queue_limit_alignment_offset(&q->limits,
1030 				bdev->bd_start_sect);
1031 	return q->limits.alignment_offset;
1032 }
1033 
1034 static inline int queue_discard_alignment(const struct request_queue *q)
1035 {
1036 	if (q->limits.discard_misaligned)
1037 		return -1;
1038 
1039 	return q->limits.discard_alignment;
1040 }
1041 
1042 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1043 {
1044 	unsigned int alignment, granularity, offset;
1045 
1046 	if (!lim->max_discard_sectors)
1047 		return 0;
1048 
1049 	/* Why are these in bytes, not sectors? */
1050 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
1051 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
1052 	if (!granularity)
1053 		return 0;
1054 
1055 	/* Offset of the partition start in 'granularity' sectors */
1056 	offset = sector_div(sector, granularity);
1057 
1058 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
1059 	offset = (granularity + alignment - offset) % granularity;
1060 
1061 	/* Turn it back into bytes, gaah */
1062 	return offset << SECTOR_SHIFT;
1063 }
1064 
1065 static inline int bdev_discard_alignment(struct block_device *bdev)
1066 {
1067 	struct request_queue *q = bdev_get_queue(bdev);
1068 
1069 	if (bdev_is_partition(bdev))
1070 		return queue_limit_discard_alignment(&q->limits,
1071 				bdev->bd_start_sect);
1072 	return q->limits.discard_alignment;
1073 }
1074 
1075 static inline unsigned int bdev_write_same(struct block_device *bdev)
1076 {
1077 	struct request_queue *q = bdev_get_queue(bdev);
1078 
1079 	if (q)
1080 		return q->limits.max_write_same_sectors;
1081 
1082 	return 0;
1083 }
1084 
1085 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1086 {
1087 	struct request_queue *q = bdev_get_queue(bdev);
1088 
1089 	if (q)
1090 		return q->limits.max_write_zeroes_sectors;
1091 
1092 	return 0;
1093 }
1094 
1095 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1096 {
1097 	struct request_queue *q = bdev_get_queue(bdev);
1098 
1099 	if (q)
1100 		return blk_queue_zoned_model(q);
1101 
1102 	return BLK_ZONED_NONE;
1103 }
1104 
1105 static inline bool bdev_is_zoned(struct block_device *bdev)
1106 {
1107 	struct request_queue *q = bdev_get_queue(bdev);
1108 
1109 	if (q)
1110 		return blk_queue_is_zoned(q);
1111 
1112 	return false;
1113 }
1114 
1115 static inline sector_t bdev_zone_sectors(struct block_device *bdev)
1116 {
1117 	struct request_queue *q = bdev_get_queue(bdev);
1118 
1119 	if (q)
1120 		return blk_queue_zone_sectors(q);
1121 	return 0;
1122 }
1123 
1124 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
1125 {
1126 	struct request_queue *q = bdev_get_queue(bdev);
1127 
1128 	if (q)
1129 		return queue_max_open_zones(q);
1130 	return 0;
1131 }
1132 
1133 static inline unsigned int bdev_max_active_zones(struct block_device *bdev)
1134 {
1135 	struct request_queue *q = bdev_get_queue(bdev);
1136 
1137 	if (q)
1138 		return queue_max_active_zones(q);
1139 	return 0;
1140 }
1141 
1142 static inline int queue_dma_alignment(const struct request_queue *q)
1143 {
1144 	return q ? q->dma_alignment : 511;
1145 }
1146 
1147 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1148 				 unsigned int len)
1149 {
1150 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1151 	return !(addr & alignment) && !(len & alignment);
1152 }
1153 
1154 /* assumes size > 256 */
1155 static inline unsigned int blksize_bits(unsigned int size)
1156 {
1157 	unsigned int bits = 8;
1158 	do {
1159 		bits++;
1160 		size >>= 1;
1161 	} while (size > 256);
1162 	return bits;
1163 }
1164 
1165 static inline unsigned int block_size(struct block_device *bdev)
1166 {
1167 	return 1 << bdev->bd_inode->i_blkbits;
1168 }
1169 
1170 int kblockd_schedule_work(struct work_struct *work);
1171 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1172 
1173 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1174 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1175 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1176 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1177 
1178 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1179 
1180 bool blk_crypto_register(struct blk_crypto_profile *profile,
1181 			 struct request_queue *q);
1182 
1183 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1184 
1185 static inline bool blk_crypto_register(struct blk_crypto_profile *profile,
1186 				       struct request_queue *q)
1187 {
1188 	return true;
1189 }
1190 
1191 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
1192 
1193 enum blk_unique_id {
1194 	/* these match the Designator Types specified in SPC */
1195 	BLK_UID_T10	= 1,
1196 	BLK_UID_EUI64	= 2,
1197 	BLK_UID_NAA	= 3,
1198 };
1199 
1200 #define NFL4_UFLG_MASK			0x0000003F
1201 
1202 struct block_device_operations {
1203 	void (*submit_bio)(struct bio *bio);
1204 	int (*open) (struct block_device *, fmode_t);
1205 	void (*release) (struct gendisk *, fmode_t);
1206 	int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
1207 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1208 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1209 	unsigned int (*check_events) (struct gendisk *disk,
1210 				      unsigned int clearing);
1211 	void (*unlock_native_capacity) (struct gendisk *);
1212 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1213 	int (*set_read_only)(struct block_device *bdev, bool ro);
1214 	/* this callback is with swap_lock and sometimes page table lock held */
1215 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1216 	int (*report_zones)(struct gendisk *, sector_t sector,
1217 			unsigned int nr_zones, report_zones_cb cb, void *data);
1218 	char *(*devnode)(struct gendisk *disk, umode_t *mode);
1219 	/* returns the length of the identifier or a negative errno: */
1220 	int (*get_unique_id)(struct gendisk *disk, u8 id[16],
1221 			enum blk_unique_id id_type);
1222 	struct module *owner;
1223 	const struct pr_ops *pr_ops;
1224 
1225 	/*
1226 	 * Special callback for probing GPT entry at a given sector.
1227 	 * Needed by Android devices, used by GPT scanner and MMC blk
1228 	 * driver.
1229 	 */
1230 	int (*alternative_gpt_sector)(struct gendisk *disk, sector_t *sector);
1231 };
1232 
1233 #ifdef CONFIG_COMPAT
1234 extern int blkdev_compat_ptr_ioctl(struct block_device *, fmode_t,
1235 				      unsigned int, unsigned long);
1236 #else
1237 #define blkdev_compat_ptr_ioctl NULL
1238 #endif
1239 
1240 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1241 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1242 						struct writeback_control *);
1243 
1244 static inline void blk_wake_io_task(struct task_struct *waiter)
1245 {
1246 	/*
1247 	 * If we're polling, the task itself is doing the completions. For
1248 	 * that case, we don't need to signal a wakeup, it's enough to just
1249 	 * mark us as RUNNING.
1250 	 */
1251 	if (waiter == current)
1252 		__set_current_state(TASK_RUNNING);
1253 	else
1254 		wake_up_process(waiter);
1255 }
1256 
1257 unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
1258 		unsigned int op);
1259 void disk_end_io_acct(struct gendisk *disk, unsigned int op,
1260 		unsigned long start_time);
1261 
1262 void bio_start_io_acct_time(struct bio *bio, unsigned long start_time);
1263 unsigned long bio_start_io_acct(struct bio *bio);
1264 void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time,
1265 		struct block_device *orig_bdev);
1266 
1267 /**
1268  * bio_end_io_acct - end I/O accounting for bio based drivers
1269  * @bio:	bio to end account for
1270  * @start:	start time returned by bio_start_io_acct()
1271  */
1272 static inline void bio_end_io_acct(struct bio *bio, unsigned long start_time)
1273 {
1274 	return bio_end_io_acct_remapped(bio, start_time, bio->bi_bdev);
1275 }
1276 
1277 int bdev_read_only(struct block_device *bdev);
1278 int set_blocksize(struct block_device *bdev, int size);
1279 
1280 const char *bdevname(struct block_device *bdev, char *buffer);
1281 int lookup_bdev(const char *pathname, dev_t *dev);
1282 
1283 void blkdev_show(struct seq_file *seqf, off_t offset);
1284 
1285 #define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
1286 #define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
1287 #ifdef CONFIG_BLOCK
1288 #define BLKDEV_MAJOR_MAX	512
1289 #else
1290 #define BLKDEV_MAJOR_MAX	0
1291 #endif
1292 
1293 struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
1294 		void *holder);
1295 struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
1296 int bd_prepare_to_claim(struct block_device *bdev, void *holder);
1297 void bd_abort_claiming(struct block_device *bdev, void *holder);
1298 void blkdev_put(struct block_device *bdev, fmode_t mode);
1299 
1300 /* just for blk-cgroup, don't use elsewhere */
1301 struct block_device *blkdev_get_no_open(dev_t dev);
1302 void blkdev_put_no_open(struct block_device *bdev);
1303 
1304 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
1305 void bdev_add(struct block_device *bdev, dev_t dev);
1306 struct block_device *I_BDEV(struct inode *inode);
1307 int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart,
1308 		loff_t lend);
1309 
1310 #ifdef CONFIG_BLOCK
1311 void invalidate_bdev(struct block_device *bdev);
1312 int sync_blockdev(struct block_device *bdev);
1313 int sync_blockdev_nowait(struct block_device *bdev);
1314 void sync_bdevs(bool wait);
1315 #else
1316 static inline void invalidate_bdev(struct block_device *bdev)
1317 {
1318 }
1319 static inline int sync_blockdev(struct block_device *bdev)
1320 {
1321 	return 0;
1322 }
1323 static inline int sync_blockdev_nowait(struct block_device *bdev)
1324 {
1325 	return 0;
1326 }
1327 static inline void sync_bdevs(bool wait)
1328 {
1329 }
1330 #endif
1331 int fsync_bdev(struct block_device *bdev);
1332 
1333 int freeze_bdev(struct block_device *bdev);
1334 int thaw_bdev(struct block_device *bdev);
1335 
1336 struct io_comp_batch {
1337 	struct request *req_list;
1338 	bool need_ts;
1339 	void (*complete)(struct io_comp_batch *);
1340 };
1341 
1342 #define DEFINE_IO_COMP_BATCH(name)	struct io_comp_batch name = { }
1343 
1344 #endif /* _LINUX_BLKDEV_H */
1345