xref: /linux-6.15/include/linux/blkdev.h (revision 21de80b5)
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/sched/clock.h>
7 #include <linux/major.h>
8 #include <linux/genhd.h>
9 #include <linux/list.h>
10 #include <linux/llist.h>
11 #include <linux/minmax.h>
12 #include <linux/timer.h>
13 #include <linux/workqueue.h>
14 #include <linux/backing-dev-defs.h>
15 #include <linux/wait.h>
16 #include <linux/mempool.h>
17 #include <linux/pfn.h>
18 #include <linux/bio.h>
19 #include <linux/stringify.h>
20 #include <linux/gfp.h>
21 #include <linux/bsg.h>
22 #include <linux/smp.h>
23 #include <linux/rcupdate.h>
24 #include <linux/percpu-refcount.h>
25 #include <linux/scatterlist.h>
26 #include <linux/blkzoned.h>
27 #include <linux/pm.h>
28 #include <linux/sbitmap.h>
29 
30 struct module;
31 struct scsi_ioctl_command;
32 
33 struct request_queue;
34 struct elevator_queue;
35 struct blk_trace;
36 struct request;
37 struct sg_io_hdr;
38 struct bsg_job;
39 struct blkcg_gq;
40 struct blk_flush_queue;
41 struct pr_ops;
42 struct rq_qos;
43 struct blk_queue_stats;
44 struct blk_stat_callback;
45 struct blk_keyslot_manager;
46 
47 #define BLKDEV_MIN_RQ	4
48 #define BLKDEV_MAX_RQ	128	/* Default maximum */
49 
50 /* Must be consistent with blk_mq_poll_stats_bkt() */
51 #define BLK_MQ_POLL_STATS_BKTS 16
52 
53 /* Doing classic polling */
54 #define BLK_MQ_POLL_CLASSIC -1
55 
56 /*
57  * Maximum number of blkcg policies allowed to be registered concurrently.
58  * Defined here to simplify include dependency.
59  */
60 #define BLKCG_MAX_POLS		5
61 
62 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
63 
64 /*
65  * request flags */
66 typedef __u32 __bitwise req_flags_t;
67 
68 /* drive already may have started this one */
69 #define RQF_STARTED		((__force req_flags_t)(1 << 1))
70 /* may not be passed by ioscheduler */
71 #define RQF_SOFTBARRIER		((__force req_flags_t)(1 << 3))
72 /* request for flush sequence */
73 #define RQF_FLUSH_SEQ		((__force req_flags_t)(1 << 4))
74 /* merge of different types, fail separately */
75 #define RQF_MIXED_MERGE		((__force req_flags_t)(1 << 5))
76 /* track inflight for MQ */
77 #define RQF_MQ_INFLIGHT		((__force req_flags_t)(1 << 6))
78 /* don't call prep for this one */
79 #define RQF_DONTPREP		((__force req_flags_t)(1 << 7))
80 /* vaguely specified driver internal error.  Ignored by the block layer */
81 #define RQF_FAILED		((__force req_flags_t)(1 << 10))
82 /* don't warn about errors */
83 #define RQF_QUIET		((__force req_flags_t)(1 << 11))
84 /* elevator private data attached */
85 #define RQF_ELVPRIV		((__force req_flags_t)(1 << 12))
86 /* account into disk and partition IO statistics */
87 #define RQF_IO_STAT		((__force req_flags_t)(1 << 13))
88 /* runtime pm request */
89 #define RQF_PM			((__force req_flags_t)(1 << 15))
90 /* on IO scheduler merge hash */
91 #define RQF_HASHED		((__force req_flags_t)(1 << 16))
92 /* track IO completion time */
93 #define RQF_STATS		((__force req_flags_t)(1 << 17))
94 /* Look at ->special_vec for the actual data payload instead of the
95    bio chain. */
96 #define RQF_SPECIAL_PAYLOAD	((__force req_flags_t)(1 << 18))
97 /* The per-zone write lock is held for this request */
98 #define RQF_ZONE_WRITE_LOCKED	((__force req_flags_t)(1 << 19))
99 /* already slept for hybrid poll */
100 #define RQF_MQ_POLL_SLEPT	((__force req_flags_t)(1 << 20))
101 /* ->timeout has been called, don't expire again */
102 #define RQF_TIMED_OUT		((__force req_flags_t)(1 << 21))
103 
104 /* flags that prevent us from merging requests: */
105 #define RQF_NOMERGE_FLAGS \
106 	(RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
107 
108 /*
109  * Request state for blk-mq.
110  */
111 enum mq_rq_state {
112 	MQ_RQ_IDLE		= 0,
113 	MQ_RQ_IN_FLIGHT		= 1,
114 	MQ_RQ_COMPLETE		= 2,
115 };
116 
117 /*
118  * Try to put the fields that are referenced together in the same cacheline.
119  *
120  * If you modify this structure, make sure to update blk_rq_init() and
121  * especially blk_mq_rq_ctx_init() to take care of the added fields.
122  */
123 struct request {
124 	struct request_queue *q;
125 	struct blk_mq_ctx *mq_ctx;
126 	struct blk_mq_hw_ctx *mq_hctx;
127 
128 	unsigned int cmd_flags;		/* op and common flags */
129 	req_flags_t rq_flags;
130 
131 	int tag;
132 	int internal_tag;
133 
134 	/* the following two fields are internal, NEVER access directly */
135 	unsigned int __data_len;	/* total data len */
136 	sector_t __sector;		/* sector cursor */
137 
138 	struct bio *bio;
139 	struct bio *biotail;
140 
141 	struct list_head queuelist;
142 
143 	/*
144 	 * The hash is used inside the scheduler, and killed once the
145 	 * request reaches the dispatch list. The ipi_list is only used
146 	 * to queue the request for softirq completion, which is long
147 	 * after the request has been unhashed (and even removed from
148 	 * the dispatch list).
149 	 */
150 	union {
151 		struct hlist_node hash;	/* merge hash */
152 		struct llist_node ipi_list;
153 	};
154 
155 	/*
156 	 * The rb_node is only used inside the io scheduler, requests
157 	 * are pruned when moved to the dispatch queue. So let the
158 	 * completion_data share space with the rb_node.
159 	 */
160 	union {
161 		struct rb_node rb_node;	/* sort/lookup */
162 		struct bio_vec special_vec;
163 		void *completion_data;
164 		int error_count; /* for legacy drivers, don't use */
165 	};
166 
167 	/*
168 	 * Three pointers are available for the IO schedulers, if they need
169 	 * more they have to dynamically allocate it.  Flush requests are
170 	 * never put on the IO scheduler. So let the flush fields share
171 	 * space with the elevator data.
172 	 */
173 	union {
174 		struct {
175 			struct io_cq		*icq;
176 			void			*priv[2];
177 		} elv;
178 
179 		struct {
180 			unsigned int		seq;
181 			struct list_head	list;
182 			rq_end_io_fn		*saved_end_io;
183 		} flush;
184 	};
185 
186 	struct gendisk *rq_disk;
187 	struct block_device *part;
188 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
189 	/* Time that the first bio started allocating this request. */
190 	u64 alloc_time_ns;
191 #endif
192 	/* Time that this request was allocated for this IO. */
193 	u64 start_time_ns;
194 	/* Time that I/O was submitted to the device. */
195 	u64 io_start_time_ns;
196 
197 #ifdef CONFIG_BLK_WBT
198 	unsigned short wbt_flags;
199 #endif
200 	/*
201 	 * rq sectors used for blk stats. It has the same value
202 	 * with blk_rq_sectors(rq), except that it never be zeroed
203 	 * by completion.
204 	 */
205 	unsigned short stats_sectors;
206 
207 	/*
208 	 * Number of scatter-gather DMA addr+len pairs after
209 	 * physical address coalescing is performed.
210 	 */
211 	unsigned short nr_phys_segments;
212 
213 #if defined(CONFIG_BLK_DEV_INTEGRITY)
214 	unsigned short nr_integrity_segments;
215 #endif
216 
217 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
218 	struct bio_crypt_ctx *crypt_ctx;
219 	struct blk_ksm_keyslot *crypt_keyslot;
220 #endif
221 
222 	unsigned short write_hint;
223 	unsigned short ioprio;
224 
225 	enum mq_rq_state state;
226 	refcount_t ref;
227 
228 	unsigned int timeout;
229 	unsigned long deadline;
230 
231 	union {
232 		struct __call_single_data csd;
233 		u64 fifo_time;
234 	};
235 
236 	/*
237 	 * completion callback.
238 	 */
239 	rq_end_io_fn *end_io;
240 	void *end_io_data;
241 };
242 
243 static inline bool blk_op_is_passthrough(unsigned int op)
244 {
245 	op &= REQ_OP_MASK;
246 	return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
247 }
248 
249 static inline bool blk_rq_is_passthrough(struct request *rq)
250 {
251 	return blk_op_is_passthrough(req_op(rq));
252 }
253 
254 static inline unsigned short req_get_ioprio(struct request *req)
255 {
256 	return req->ioprio;
257 }
258 
259 #include <linux/elevator.h>
260 
261 struct blk_queue_ctx;
262 
263 struct bio_vec;
264 
265 enum blk_eh_timer_return {
266 	BLK_EH_DONE,		/* drivers has completed the command */
267 	BLK_EH_RESET_TIMER,	/* reset timer and try again */
268 };
269 
270 enum blk_queue_state {
271 	Queue_down,
272 	Queue_up,
273 };
274 
275 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
276 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
277 
278 #define BLK_SCSI_MAX_CMDS	(256)
279 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
280 
281 /*
282  * Zoned block device models (zoned limit).
283  *
284  * Note: This needs to be ordered from the least to the most severe
285  * restrictions for the inheritance in blk_stack_limits() to work.
286  */
287 enum blk_zoned_model {
288 	BLK_ZONED_NONE = 0,	/* Regular block device */
289 	BLK_ZONED_HA,		/* Host-aware zoned block device */
290 	BLK_ZONED_HM,		/* Host-managed zoned block device */
291 };
292 
293 /*
294  * BLK_BOUNCE_NONE:	never bounce (default)
295  * BLK_BOUNCE_HIGH:	bounce all highmem pages
296  */
297 enum blk_bounce {
298 	BLK_BOUNCE_NONE,
299 	BLK_BOUNCE_HIGH,
300 };
301 
302 struct queue_limits {
303 	enum blk_bounce		bounce;
304 	unsigned long		seg_boundary_mask;
305 	unsigned long		virt_boundary_mask;
306 
307 	unsigned int		max_hw_sectors;
308 	unsigned int		max_dev_sectors;
309 	unsigned int		chunk_sectors;
310 	unsigned int		max_sectors;
311 	unsigned int		max_segment_size;
312 	unsigned int		physical_block_size;
313 	unsigned int		logical_block_size;
314 	unsigned int		alignment_offset;
315 	unsigned int		io_min;
316 	unsigned int		io_opt;
317 	unsigned int		max_discard_sectors;
318 	unsigned int		max_hw_discard_sectors;
319 	unsigned int		max_write_same_sectors;
320 	unsigned int		max_write_zeroes_sectors;
321 	unsigned int		max_zone_append_sectors;
322 	unsigned int		discard_granularity;
323 	unsigned int		discard_alignment;
324 	unsigned int		zone_write_granularity;
325 
326 	unsigned short		max_segments;
327 	unsigned short		max_integrity_segments;
328 	unsigned short		max_discard_segments;
329 
330 	unsigned char		misaligned;
331 	unsigned char		discard_misaligned;
332 	unsigned char		raid_partial_stripes_expensive;
333 	enum blk_zoned_model	zoned;
334 };
335 
336 typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,
337 			       void *data);
338 
339 void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model);
340 
341 #ifdef CONFIG_BLK_DEV_ZONED
342 
343 #define BLK_ALL_ZONES  ((unsigned int)-1)
344 int blkdev_report_zones(struct block_device *bdev, sector_t sector,
345 			unsigned int nr_zones, report_zones_cb cb, void *data);
346 unsigned int blkdev_nr_zones(struct gendisk *disk);
347 extern int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
348 			    sector_t sectors, sector_t nr_sectors,
349 			    gfp_t gfp_mask);
350 int blk_revalidate_disk_zones(struct gendisk *disk,
351 			      void (*update_driver_data)(struct gendisk *disk));
352 
353 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
354 				     unsigned int cmd, unsigned long arg);
355 extern int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
356 				  unsigned int cmd, unsigned long arg);
357 
358 #else /* CONFIG_BLK_DEV_ZONED */
359 
360 static inline unsigned int blkdev_nr_zones(struct gendisk *disk)
361 {
362 	return 0;
363 }
364 
365 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
366 					    fmode_t mode, unsigned int cmd,
367 					    unsigned long arg)
368 {
369 	return -ENOTTY;
370 }
371 
372 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
373 					 fmode_t mode, unsigned int cmd,
374 					 unsigned long arg)
375 {
376 	return -ENOTTY;
377 }
378 
379 #endif /* CONFIG_BLK_DEV_ZONED */
380 
381 struct request_queue {
382 	struct request		*last_merge;
383 	struct elevator_queue	*elevator;
384 
385 	struct percpu_ref	q_usage_counter;
386 
387 	struct blk_queue_stats	*stats;
388 	struct rq_qos		*rq_qos;
389 
390 	const struct blk_mq_ops	*mq_ops;
391 
392 	/* sw queues */
393 	struct blk_mq_ctx __percpu	*queue_ctx;
394 
395 	unsigned int		queue_depth;
396 
397 	/* hw dispatch queues */
398 	struct blk_mq_hw_ctx	**queue_hw_ctx;
399 	unsigned int		nr_hw_queues;
400 
401 	struct backing_dev_info	*backing_dev_info;
402 
403 	/*
404 	 * The queue owner gets to use this for whatever they like.
405 	 * ll_rw_blk doesn't touch it.
406 	 */
407 	void			*queuedata;
408 
409 	/*
410 	 * various queue flags, see QUEUE_* below
411 	 */
412 	unsigned long		queue_flags;
413 	/*
414 	 * Number of contexts that have called blk_set_pm_only(). If this
415 	 * counter is above zero then only RQF_PM requests are processed.
416 	 */
417 	atomic_t		pm_only;
418 
419 	/*
420 	 * ida allocated id for this queue.  Used to index queues from
421 	 * ioctx.
422 	 */
423 	int			id;
424 
425 	spinlock_t		queue_lock;
426 
427 	/*
428 	 * queue kobject
429 	 */
430 	struct kobject kobj;
431 
432 	/*
433 	 * mq queue kobject
434 	 */
435 	struct kobject *mq_kobj;
436 
437 #ifdef  CONFIG_BLK_DEV_INTEGRITY
438 	struct blk_integrity integrity;
439 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
440 
441 #ifdef CONFIG_PM
442 	struct device		*dev;
443 	enum rpm_status		rpm_status;
444 #endif
445 
446 	/*
447 	 * queue settings
448 	 */
449 	unsigned long		nr_requests;	/* Max # of requests */
450 
451 	unsigned int		dma_pad_mask;
452 	unsigned int		dma_alignment;
453 
454 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
455 	/* Inline crypto capabilities */
456 	struct blk_keyslot_manager *ksm;
457 #endif
458 
459 	unsigned int		rq_timeout;
460 	int			poll_nsec;
461 
462 	struct blk_stat_callback	*poll_cb;
463 	struct blk_rq_stat	poll_stat[BLK_MQ_POLL_STATS_BKTS];
464 
465 	struct timer_list	timeout;
466 	struct work_struct	timeout_work;
467 
468 	atomic_t		nr_active_requests_shared_sbitmap;
469 
470 	struct sbitmap_queue	sched_bitmap_tags;
471 	struct sbitmap_queue	sched_breserved_tags;
472 
473 	struct list_head	icq_list;
474 #ifdef CONFIG_BLK_CGROUP
475 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
476 	struct blkcg_gq		*root_blkg;
477 	struct list_head	blkg_list;
478 #endif
479 
480 	struct queue_limits	limits;
481 
482 	unsigned int		required_elevator_features;
483 
484 #ifdef CONFIG_BLK_DEV_ZONED
485 	/*
486 	 * Zoned block device information for request dispatch control.
487 	 * nr_zones is the total number of zones of the device. This is always
488 	 * 0 for regular block devices. conv_zones_bitmap is a bitmap of nr_zones
489 	 * bits which indicates if a zone is conventional (bit set) or
490 	 * sequential (bit clear). seq_zones_wlock is a bitmap of nr_zones
491 	 * bits which indicates if a zone is write locked, that is, if a write
492 	 * request targeting the zone was dispatched. All three fields are
493 	 * initialized by the low level device driver (e.g. scsi/sd.c).
494 	 * Stacking drivers (device mappers) may or may not initialize
495 	 * these fields.
496 	 *
497 	 * Reads of this information must be protected with blk_queue_enter() /
498 	 * blk_queue_exit(). Modifying this information is only allowed while
499 	 * no requests are being processed. See also blk_mq_freeze_queue() and
500 	 * blk_mq_unfreeze_queue().
501 	 */
502 	unsigned int		nr_zones;
503 	unsigned long		*conv_zones_bitmap;
504 	unsigned long		*seq_zones_wlock;
505 	unsigned int		max_open_zones;
506 	unsigned int		max_active_zones;
507 #endif /* CONFIG_BLK_DEV_ZONED */
508 
509 	/*
510 	 * sg stuff
511 	 */
512 	unsigned int		sg_timeout;
513 	unsigned int		sg_reserved_size;
514 	int			node;
515 	struct mutex		debugfs_mutex;
516 #ifdef CONFIG_BLK_DEV_IO_TRACE
517 	struct blk_trace __rcu	*blk_trace;
518 #endif
519 	/*
520 	 * for flush operations
521 	 */
522 	struct blk_flush_queue	*fq;
523 
524 	struct list_head	requeue_list;
525 	spinlock_t		requeue_lock;
526 	struct delayed_work	requeue_work;
527 
528 	struct mutex		sysfs_lock;
529 	struct mutex		sysfs_dir_lock;
530 
531 	/*
532 	 * for reusing dead hctx instance in case of updating
533 	 * nr_hw_queues
534 	 */
535 	struct list_head	unused_hctx_list;
536 	spinlock_t		unused_hctx_lock;
537 
538 	int			mq_freeze_depth;
539 
540 #if defined(CONFIG_BLK_DEV_BSG)
541 	struct bsg_class_device bsg_dev;
542 #endif
543 
544 #ifdef CONFIG_BLK_DEV_THROTTLING
545 	/* Throttle data */
546 	struct throtl_data *td;
547 #endif
548 	struct rcu_head		rcu_head;
549 	wait_queue_head_t	mq_freeze_wq;
550 	/*
551 	 * Protect concurrent access to q_usage_counter by
552 	 * percpu_ref_kill() and percpu_ref_reinit().
553 	 */
554 	struct mutex		mq_freeze_lock;
555 
556 	struct blk_mq_tag_set	*tag_set;
557 	struct list_head	tag_set_list;
558 	struct bio_set		bio_split;
559 
560 	struct dentry		*debugfs_dir;
561 
562 #ifdef CONFIG_BLK_DEBUG_FS
563 	struct dentry		*sched_debugfs_dir;
564 	struct dentry		*rqos_debugfs_dir;
565 #endif
566 
567 	bool			mq_sysfs_init_done;
568 
569 	size_t			cmd_size;
570 
571 #define BLK_MAX_WRITE_HINTS	5
572 	u64			write_hints[BLK_MAX_WRITE_HINTS];
573 };
574 
575 /* Keep blk_queue_flag_name[] in sync with the definitions below */
576 #define QUEUE_FLAG_STOPPED	0	/* queue is stopped */
577 #define QUEUE_FLAG_DYING	1	/* queue being torn down */
578 #define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
579 #define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
580 #define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
581 #define QUEUE_FLAG_NONROT	6	/* non-rotational device (SSD) */
582 #define QUEUE_FLAG_VIRT		QUEUE_FLAG_NONROT /* paravirt device */
583 #define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
584 #define QUEUE_FLAG_DISCARD	8	/* supports DISCARD */
585 #define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
586 #define QUEUE_FLAG_ADD_RANDOM	10	/* Contributes to random pool */
587 #define QUEUE_FLAG_SECERASE	11	/* supports secure erase */
588 #define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
589 #define QUEUE_FLAG_DEAD		13	/* queue tear-down finished */
590 #define QUEUE_FLAG_INIT_DONE	14	/* queue is initialized */
591 #define QUEUE_FLAG_STABLE_WRITES 15	/* don't modify blks until WB is done */
592 #define QUEUE_FLAG_POLL		16	/* IO polling enabled if set */
593 #define QUEUE_FLAG_WC		17	/* Write back caching */
594 #define QUEUE_FLAG_FUA		18	/* device supports FUA writes */
595 #define QUEUE_FLAG_DAX		19	/* device supports DAX */
596 #define QUEUE_FLAG_STATS	20	/* track IO start and completion times */
597 #define QUEUE_FLAG_POLL_STATS	21	/* collecting stats for hybrid polling */
598 #define QUEUE_FLAG_REGISTERED	22	/* queue has been registered to a disk */
599 #define QUEUE_FLAG_SCSI_PASSTHROUGH 23	/* queue supports SCSI commands */
600 #define QUEUE_FLAG_QUIESCED	24	/* queue has been quiesced */
601 #define QUEUE_FLAG_PCI_P2PDMA	25	/* device supports PCI p2p requests */
602 #define QUEUE_FLAG_ZONE_RESETALL 26	/* supports Zone Reset All */
603 #define QUEUE_FLAG_RQ_ALLOC_TIME 27	/* record rq->alloc_time_ns */
604 #define QUEUE_FLAG_HCTX_ACTIVE	28	/* at least one blk-mq hctx is active */
605 #define QUEUE_FLAG_NOWAIT       29	/* device supports NOWAIT */
606 
607 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
608 				 (1 << QUEUE_FLAG_SAME_COMP) |		\
609 				 (1 << QUEUE_FLAG_NOWAIT))
610 
611 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
612 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
613 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
614 
615 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
616 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
617 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
618 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
619 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
620 #define blk_queue_noxmerges(q)	\
621 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
622 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
623 #define blk_queue_stable_writes(q) \
624 	test_bit(QUEUE_FLAG_STABLE_WRITES, &(q)->queue_flags)
625 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
626 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
627 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
628 #define blk_queue_zone_resetall(q)	\
629 	test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
630 #define blk_queue_secure_erase(q) \
631 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
632 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
633 #define blk_queue_scsi_passthrough(q)	\
634 	test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
635 #define blk_queue_pci_p2pdma(q)	\
636 	test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
637 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
638 #define blk_queue_rq_alloc_time(q)	\
639 	test_bit(QUEUE_FLAG_RQ_ALLOC_TIME, &(q)->queue_flags)
640 #else
641 #define blk_queue_rq_alloc_time(q)	false
642 #endif
643 
644 #define blk_noretry_request(rq) \
645 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
646 			     REQ_FAILFAST_DRIVER))
647 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
648 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
649 #define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
650 #define blk_queue_registered(q)	test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
651 #define blk_queue_nowait(q)	test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags)
652 
653 extern void blk_set_pm_only(struct request_queue *q);
654 extern void blk_clear_pm_only(struct request_queue *q);
655 
656 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
657 
658 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
659 
660 #define rq_dma_dir(rq) \
661 	(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
662 
663 #define dma_map_bvec(dev, bv, dir, attrs) \
664 	dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
665 	(dir), (attrs))
666 
667 #define queue_to_disk(q)	(dev_to_disk(kobj_to_dev((q)->kobj.parent)))
668 
669 static inline bool queue_is_mq(struct request_queue *q)
670 {
671 	return q->mq_ops;
672 }
673 
674 #ifdef CONFIG_PM
675 static inline enum rpm_status queue_rpm_status(struct request_queue *q)
676 {
677 	return q->rpm_status;
678 }
679 #else
680 static inline enum rpm_status queue_rpm_status(struct request_queue *q)
681 {
682 	return RPM_ACTIVE;
683 }
684 #endif
685 
686 static inline enum blk_zoned_model
687 blk_queue_zoned_model(struct request_queue *q)
688 {
689 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
690 		return q->limits.zoned;
691 	return BLK_ZONED_NONE;
692 }
693 
694 static inline bool blk_queue_is_zoned(struct request_queue *q)
695 {
696 	switch (blk_queue_zoned_model(q)) {
697 	case BLK_ZONED_HA:
698 	case BLK_ZONED_HM:
699 		return true;
700 	default:
701 		return false;
702 	}
703 }
704 
705 static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
706 {
707 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
708 }
709 
710 #ifdef CONFIG_BLK_DEV_ZONED
711 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
712 {
713 	return blk_queue_is_zoned(q) ? q->nr_zones : 0;
714 }
715 
716 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
717 					     sector_t sector)
718 {
719 	if (!blk_queue_is_zoned(q))
720 		return 0;
721 	return sector >> ilog2(q->limits.chunk_sectors);
722 }
723 
724 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
725 					 sector_t sector)
726 {
727 	if (!blk_queue_is_zoned(q))
728 		return false;
729 	if (!q->conv_zones_bitmap)
730 		return true;
731 	return !test_bit(blk_queue_zone_no(q, sector), q->conv_zones_bitmap);
732 }
733 
734 static inline void blk_queue_max_open_zones(struct request_queue *q,
735 		unsigned int max_open_zones)
736 {
737 	q->max_open_zones = max_open_zones;
738 }
739 
740 static inline unsigned int queue_max_open_zones(const struct request_queue *q)
741 {
742 	return q->max_open_zones;
743 }
744 
745 static inline void blk_queue_max_active_zones(struct request_queue *q,
746 		unsigned int max_active_zones)
747 {
748 	q->max_active_zones = max_active_zones;
749 }
750 
751 static inline unsigned int queue_max_active_zones(const struct request_queue *q)
752 {
753 	return q->max_active_zones;
754 }
755 #else /* CONFIG_BLK_DEV_ZONED */
756 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
757 {
758 	return 0;
759 }
760 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
761 					 sector_t sector)
762 {
763 	return false;
764 }
765 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
766 					     sector_t sector)
767 {
768 	return 0;
769 }
770 static inline unsigned int queue_max_open_zones(const struct request_queue *q)
771 {
772 	return 0;
773 }
774 static inline unsigned int queue_max_active_zones(const struct request_queue *q)
775 {
776 	return 0;
777 }
778 #endif /* CONFIG_BLK_DEV_ZONED */
779 
780 static inline bool rq_is_sync(struct request *rq)
781 {
782 	return op_is_sync(rq->cmd_flags);
783 }
784 
785 static inline bool rq_mergeable(struct request *rq)
786 {
787 	if (blk_rq_is_passthrough(rq))
788 		return false;
789 
790 	if (req_op(rq) == REQ_OP_FLUSH)
791 		return false;
792 
793 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
794 		return false;
795 
796 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
797 		return false;
798 
799 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
800 		return false;
801 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
802 		return false;
803 
804 	return true;
805 }
806 
807 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
808 {
809 	if (bio_page(a) == bio_page(b) &&
810 	    bio_offset(a) == bio_offset(b))
811 		return true;
812 
813 	return false;
814 }
815 
816 static inline unsigned int blk_queue_depth(struct request_queue *q)
817 {
818 	if (q->queue_depth)
819 		return q->queue_depth;
820 
821 	return q->nr_requests;
822 }
823 
824 /*
825  * default timeout for SG_IO if none specified
826  */
827 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
828 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
829 
830 struct rq_map_data {
831 	struct page **pages;
832 	int page_order;
833 	int nr_entries;
834 	unsigned long offset;
835 	int null_mapped;
836 	int from_user;
837 };
838 
839 struct req_iterator {
840 	struct bvec_iter iter;
841 	struct bio *bio;
842 };
843 
844 /* This should not be used directly - use rq_for_each_segment */
845 #define for_each_bio(_bio)		\
846 	for (; _bio; _bio = _bio->bi_next)
847 #define __rq_for_each_bio(_bio, rq)	\
848 	if ((rq->bio))			\
849 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
850 
851 #define rq_for_each_segment(bvl, _rq, _iter)			\
852 	__rq_for_each_bio(_iter.bio, _rq)			\
853 		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
854 
855 #define rq_for_each_bvec(bvl, _rq, _iter)			\
856 	__rq_for_each_bio(_iter.bio, _rq)			\
857 		bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
858 
859 #define rq_iter_last(bvec, _iter)				\
860 		(_iter.bio->bi_next == NULL &&			\
861 		 bio_iter_last(bvec, _iter.iter))
862 
863 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
864 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
865 #endif
866 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
867 extern void rq_flush_dcache_pages(struct request *rq);
868 #else
869 static inline void rq_flush_dcache_pages(struct request *rq)
870 {
871 }
872 #endif
873 
874 extern int blk_register_queue(struct gendisk *disk);
875 extern void blk_unregister_queue(struct gendisk *disk);
876 blk_qc_t submit_bio_noacct(struct bio *bio);
877 extern void blk_rq_init(struct request_queue *q, struct request *rq);
878 extern void blk_put_request(struct request *);
879 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
880 				       blk_mq_req_flags_t flags);
881 extern int blk_lld_busy(struct request_queue *q);
882 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
883 			     struct bio_set *bs, gfp_t gfp_mask,
884 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
885 			     void *data);
886 extern void blk_rq_unprep_clone(struct request *rq);
887 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
888 				     struct request *rq);
889 int blk_rq_append_bio(struct request *rq, struct bio *bio);
890 extern void blk_queue_split(struct bio **);
891 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
892 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
893 			      unsigned int, void __user *);
894 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
895 			  unsigned int, void __user *);
896 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
897 			 struct scsi_ioctl_command __user *);
898 extern int get_sg_io_hdr(struct sg_io_hdr *hdr, const void __user *argp);
899 extern int put_sg_io_hdr(const struct sg_io_hdr *hdr, void __user *argp);
900 
901 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
902 extern void blk_queue_exit(struct request_queue *q);
903 extern void blk_sync_queue(struct request_queue *q);
904 extern int blk_rq_map_user(struct request_queue *, struct request *,
905 			   struct rq_map_data *, void __user *, unsigned long,
906 			   gfp_t);
907 extern int blk_rq_unmap_user(struct bio *);
908 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
909 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
910 			       struct rq_map_data *, const struct iov_iter *,
911 			       gfp_t);
912 extern void blk_execute_rq_nowait(struct gendisk *,
913 				  struct request *, int, rq_end_io_fn *);
914 
915 blk_status_t blk_execute_rq(struct gendisk *bd_disk, struct request *rq,
916 			    int at_head);
917 
918 /* Helper to convert REQ_OP_XXX to its string format XXX */
919 extern const char *blk_op_str(unsigned int op);
920 
921 int blk_status_to_errno(blk_status_t status);
922 blk_status_t errno_to_blk_status(int errno);
923 
924 int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin);
925 
926 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
927 {
928 	return bdev->bd_disk->queue;	/* this is never NULL */
929 }
930 
931 /*
932  * The basic unit of block I/O is a sector. It is used in a number of contexts
933  * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
934  * bytes. Variables of type sector_t represent an offset or size that is a
935  * multiple of 512 bytes. Hence these two constants.
936  */
937 #ifndef SECTOR_SHIFT
938 #define SECTOR_SHIFT 9
939 #endif
940 #ifndef SECTOR_SIZE
941 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
942 #endif
943 
944 /*
945  * blk_rq_pos()			: the current sector
946  * blk_rq_bytes()		: bytes left in the entire request
947  * blk_rq_cur_bytes()		: bytes left in the current segment
948  * blk_rq_err_bytes()		: bytes left till the next error boundary
949  * blk_rq_sectors()		: sectors left in the entire request
950  * blk_rq_cur_sectors()		: sectors left in the current segment
951  * blk_rq_stats_sectors()	: sectors of the entire request used for stats
952  */
953 static inline sector_t blk_rq_pos(const struct request *rq)
954 {
955 	return rq->__sector;
956 }
957 
958 static inline unsigned int blk_rq_bytes(const struct request *rq)
959 {
960 	return rq->__data_len;
961 }
962 
963 static inline int blk_rq_cur_bytes(const struct request *rq)
964 {
965 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
966 }
967 
968 extern unsigned int blk_rq_err_bytes(const struct request *rq);
969 
970 static inline unsigned int blk_rq_sectors(const struct request *rq)
971 {
972 	return blk_rq_bytes(rq) >> SECTOR_SHIFT;
973 }
974 
975 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
976 {
977 	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
978 }
979 
980 static inline unsigned int blk_rq_stats_sectors(const struct request *rq)
981 {
982 	return rq->stats_sectors;
983 }
984 
985 #ifdef CONFIG_BLK_DEV_ZONED
986 
987 /* Helper to convert BLK_ZONE_ZONE_XXX to its string format XXX */
988 const char *blk_zone_cond_str(enum blk_zone_cond zone_cond);
989 
990 static inline unsigned int bio_zone_no(struct bio *bio)
991 {
992 	return blk_queue_zone_no(bdev_get_queue(bio->bi_bdev),
993 				 bio->bi_iter.bi_sector);
994 }
995 
996 static inline unsigned int bio_zone_is_seq(struct bio *bio)
997 {
998 	return blk_queue_zone_is_seq(bdev_get_queue(bio->bi_bdev),
999 				     bio->bi_iter.bi_sector);
1000 }
1001 
1002 static inline unsigned int blk_rq_zone_no(struct request *rq)
1003 {
1004 	return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
1005 }
1006 
1007 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
1008 {
1009 	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
1010 }
1011 #endif /* CONFIG_BLK_DEV_ZONED */
1012 
1013 /*
1014  * Some commands like WRITE SAME have a payload or data transfer size which
1015  * is different from the size of the request.  Any driver that supports such
1016  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
1017  * calculate the data transfer size.
1018  */
1019 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
1020 {
1021 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1022 		return rq->special_vec.bv_len;
1023 	return blk_rq_bytes(rq);
1024 }
1025 
1026 /*
1027  * Return the first full biovec in the request.  The caller needs to check that
1028  * there are any bvecs before calling this helper.
1029  */
1030 static inline struct bio_vec req_bvec(struct request *rq)
1031 {
1032 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1033 		return rq->special_vec;
1034 	return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
1035 }
1036 
1037 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
1038 						     int op)
1039 {
1040 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
1041 		return min(q->limits.max_discard_sectors,
1042 			   UINT_MAX >> SECTOR_SHIFT);
1043 
1044 	if (unlikely(op == REQ_OP_WRITE_SAME))
1045 		return q->limits.max_write_same_sectors;
1046 
1047 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
1048 		return q->limits.max_write_zeroes_sectors;
1049 
1050 	return q->limits.max_sectors;
1051 }
1052 
1053 /*
1054  * Return maximum size of a request at given offset. Only valid for
1055  * file system requests.
1056  */
1057 static inline unsigned int blk_max_size_offset(struct request_queue *q,
1058 					       sector_t offset,
1059 					       unsigned int chunk_sectors)
1060 {
1061 	if (!chunk_sectors) {
1062 		if (q->limits.chunk_sectors)
1063 			chunk_sectors = q->limits.chunk_sectors;
1064 		else
1065 			return q->limits.max_sectors;
1066 	}
1067 
1068 	if (likely(is_power_of_2(chunk_sectors)))
1069 		chunk_sectors -= offset & (chunk_sectors - 1);
1070 	else
1071 		chunk_sectors -= sector_div(offset, chunk_sectors);
1072 
1073 	return min(q->limits.max_sectors, chunk_sectors);
1074 }
1075 
1076 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
1077 						  sector_t offset)
1078 {
1079 	struct request_queue *q = rq->q;
1080 
1081 	if (blk_rq_is_passthrough(rq))
1082 		return q->limits.max_hw_sectors;
1083 
1084 	if (!q->limits.chunk_sectors ||
1085 	    req_op(rq) == REQ_OP_DISCARD ||
1086 	    req_op(rq) == REQ_OP_SECURE_ERASE)
1087 		return blk_queue_get_max_sectors(q, req_op(rq));
1088 
1089 	return min(blk_max_size_offset(q, offset, 0),
1090 			blk_queue_get_max_sectors(q, req_op(rq)));
1091 }
1092 
1093 static inline unsigned int blk_rq_count_bios(struct request *rq)
1094 {
1095 	unsigned int nr_bios = 0;
1096 	struct bio *bio;
1097 
1098 	__rq_for_each_bio(bio, rq)
1099 		nr_bios++;
1100 
1101 	return nr_bios;
1102 }
1103 
1104 void blk_steal_bios(struct bio_list *list, struct request *rq);
1105 
1106 /*
1107  * Request completion related functions.
1108  *
1109  * blk_update_request() completes given number of bytes and updates
1110  * the request without completing it.
1111  */
1112 extern bool blk_update_request(struct request *rq, blk_status_t error,
1113 			       unsigned int nr_bytes);
1114 
1115 extern void blk_abort_request(struct request *);
1116 
1117 /*
1118  * Access functions for manipulating queue properties
1119  */
1120 extern void blk_cleanup_queue(struct request_queue *);
1121 void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce limit);
1122 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1123 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1124 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1125 extern void blk_queue_max_discard_segments(struct request_queue *,
1126 		unsigned short);
1127 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1128 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1129 		unsigned int max_discard_sectors);
1130 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1131 		unsigned int max_write_same_sectors);
1132 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1133 		unsigned int max_write_same_sectors);
1134 extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
1135 extern void blk_queue_max_zone_append_sectors(struct request_queue *q,
1136 		unsigned int max_zone_append_sectors);
1137 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1138 void blk_queue_zone_write_granularity(struct request_queue *q,
1139 				      unsigned int size);
1140 extern void blk_queue_alignment_offset(struct request_queue *q,
1141 				       unsigned int alignment);
1142 void blk_queue_update_readahead(struct request_queue *q);
1143 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1144 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1145 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1146 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1147 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1148 extern void blk_set_default_limits(struct queue_limits *lim);
1149 extern void blk_set_stacking_limits(struct queue_limits *lim);
1150 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1151 			    sector_t offset);
1152 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1153 			      sector_t offset);
1154 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1155 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1156 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1157 extern void blk_queue_dma_alignment(struct request_queue *, int);
1158 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1159 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1160 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1161 extern void blk_queue_required_elevator_features(struct request_queue *q,
1162 						 unsigned int features);
1163 extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
1164 					      struct device *dev);
1165 
1166 /*
1167  * Number of physical segments as sent to the device.
1168  *
1169  * Normally this is the number of discontiguous data segments sent by the
1170  * submitter.  But for data-less command like discard we might have no
1171  * actual data segments submitted, but the driver might have to add it's
1172  * own special payload.  In that case we still return 1 here so that this
1173  * special payload will be mapped.
1174  */
1175 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1176 {
1177 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1178 		return 1;
1179 	return rq->nr_phys_segments;
1180 }
1181 
1182 /*
1183  * Number of discard segments (or ranges) the driver needs to fill in.
1184  * Each discard bio merged into a request is counted as one segment.
1185  */
1186 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1187 {
1188 	return max_t(unsigned short, rq->nr_phys_segments, 1);
1189 }
1190 
1191 int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
1192 		struct scatterlist *sglist, struct scatterlist **last_sg);
1193 static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq,
1194 		struct scatterlist *sglist)
1195 {
1196 	struct scatterlist *last_sg = NULL;
1197 
1198 	return __blk_rq_map_sg(q, rq, sglist, &last_sg);
1199 }
1200 extern void blk_dump_rq_flags(struct request *, char *);
1201 
1202 bool __must_check blk_get_queue(struct request_queue *);
1203 extern void blk_put_queue(struct request_queue *);
1204 extern void blk_set_queue_dying(struct request_queue *);
1205 
1206 #ifdef CONFIG_BLOCK
1207 /*
1208  * blk_plug permits building a queue of related requests by holding the I/O
1209  * fragments for a short period. This allows merging of sequential requests
1210  * into single larger request. As the requests are moved from a per-task list to
1211  * the device's request_queue in a batch, this results in improved scalability
1212  * as the lock contention for request_queue lock is reduced.
1213  *
1214  * It is ok not to disable preemption when adding the request to the plug list
1215  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1216  * the plug list when the task sleeps by itself. For details, please see
1217  * schedule() where blk_schedule_flush_plug() is called.
1218  */
1219 struct blk_plug {
1220 	struct list_head mq_list; /* blk-mq requests */
1221 	struct list_head cb_list; /* md requires an unplug callback */
1222 	unsigned short rq_count;
1223 	bool multiple_queues;
1224 	bool nowait;
1225 };
1226 #define BLK_MAX_REQUEST_COUNT 16
1227 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1228 
1229 struct blk_plug_cb;
1230 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1231 struct blk_plug_cb {
1232 	struct list_head list;
1233 	blk_plug_cb_fn callback;
1234 	void *data;
1235 };
1236 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1237 					     void *data, int size);
1238 extern void blk_start_plug(struct blk_plug *);
1239 extern void blk_finish_plug(struct blk_plug *);
1240 extern void blk_flush_plug_list(struct blk_plug *, bool);
1241 
1242 static inline void blk_flush_plug(struct task_struct *tsk)
1243 {
1244 	struct blk_plug *plug = tsk->plug;
1245 
1246 	if (plug)
1247 		blk_flush_plug_list(plug, false);
1248 }
1249 
1250 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1251 {
1252 	struct blk_plug *plug = tsk->plug;
1253 
1254 	if (plug)
1255 		blk_flush_plug_list(plug, true);
1256 }
1257 
1258 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1259 {
1260 	struct blk_plug *plug = tsk->plug;
1261 
1262 	return plug &&
1263 		 (!list_empty(&plug->mq_list) ||
1264 		 !list_empty(&plug->cb_list));
1265 }
1266 
1267 int blkdev_issue_flush(struct block_device *bdev);
1268 long nr_blockdev_pages(void);
1269 #else /* CONFIG_BLOCK */
1270 struct blk_plug {
1271 };
1272 
1273 static inline void blk_start_plug(struct blk_plug *plug)
1274 {
1275 }
1276 
1277 static inline void blk_finish_plug(struct blk_plug *plug)
1278 {
1279 }
1280 
1281 static inline void blk_flush_plug(struct task_struct *task)
1282 {
1283 }
1284 
1285 static inline void blk_schedule_flush_plug(struct task_struct *task)
1286 {
1287 }
1288 
1289 
1290 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1291 {
1292 	return false;
1293 }
1294 
1295 static inline int blkdev_issue_flush(struct block_device *bdev)
1296 {
1297 	return 0;
1298 }
1299 
1300 static inline long nr_blockdev_pages(void)
1301 {
1302 	return 0;
1303 }
1304 #endif /* CONFIG_BLOCK */
1305 
1306 extern void blk_io_schedule(void);
1307 
1308 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1309 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1310 
1311 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
1312 
1313 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1314 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1315 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1316 		sector_t nr_sects, gfp_t gfp_mask, int flags,
1317 		struct bio **biop);
1318 
1319 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
1320 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
1321 
1322 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1323 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1324 		unsigned flags);
1325 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1326 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1327 
1328 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1329 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1330 {
1331 	return blkdev_issue_discard(sb->s_bdev,
1332 				    block << (sb->s_blocksize_bits -
1333 					      SECTOR_SHIFT),
1334 				    nr_blocks << (sb->s_blocksize_bits -
1335 						  SECTOR_SHIFT),
1336 				    gfp_mask, flags);
1337 }
1338 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1339 		sector_t nr_blocks, gfp_t gfp_mask)
1340 {
1341 	return blkdev_issue_zeroout(sb->s_bdev,
1342 				    block << (sb->s_blocksize_bits -
1343 					      SECTOR_SHIFT),
1344 				    nr_blocks << (sb->s_blocksize_bits -
1345 						  SECTOR_SHIFT),
1346 				    gfp_mask, 0);
1347 }
1348 
1349 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1350 
1351 static inline bool bdev_is_partition(struct block_device *bdev)
1352 {
1353 	return bdev->bd_partno;
1354 }
1355 
1356 enum blk_default_limits {
1357 	BLK_MAX_SEGMENTS	= 128,
1358 	BLK_SAFE_MAX_SECTORS	= 255,
1359 	BLK_DEF_MAX_SECTORS	= 2560,
1360 	BLK_MAX_SEGMENT_SIZE	= 65536,
1361 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
1362 };
1363 
1364 static inline unsigned long queue_segment_boundary(const struct request_queue *q)
1365 {
1366 	return q->limits.seg_boundary_mask;
1367 }
1368 
1369 static inline unsigned long queue_virt_boundary(const struct request_queue *q)
1370 {
1371 	return q->limits.virt_boundary_mask;
1372 }
1373 
1374 static inline unsigned int queue_max_sectors(const struct request_queue *q)
1375 {
1376 	return q->limits.max_sectors;
1377 }
1378 
1379 static inline unsigned int queue_max_hw_sectors(const struct request_queue *q)
1380 {
1381 	return q->limits.max_hw_sectors;
1382 }
1383 
1384 static inline unsigned short queue_max_segments(const struct request_queue *q)
1385 {
1386 	return q->limits.max_segments;
1387 }
1388 
1389 static inline unsigned short queue_max_discard_segments(const struct request_queue *q)
1390 {
1391 	return q->limits.max_discard_segments;
1392 }
1393 
1394 static inline unsigned int queue_max_segment_size(const struct request_queue *q)
1395 {
1396 	return q->limits.max_segment_size;
1397 }
1398 
1399 static inline unsigned int queue_max_zone_append_sectors(const struct request_queue *q)
1400 {
1401 
1402 	const struct queue_limits *l = &q->limits;
1403 
1404 	return min(l->max_zone_append_sectors, l->max_sectors);
1405 }
1406 
1407 static inline unsigned queue_logical_block_size(const struct request_queue *q)
1408 {
1409 	int retval = 512;
1410 
1411 	if (q && q->limits.logical_block_size)
1412 		retval = q->limits.logical_block_size;
1413 
1414 	return retval;
1415 }
1416 
1417 static inline unsigned int bdev_logical_block_size(struct block_device *bdev)
1418 {
1419 	return queue_logical_block_size(bdev_get_queue(bdev));
1420 }
1421 
1422 static inline unsigned int queue_physical_block_size(const struct request_queue *q)
1423 {
1424 	return q->limits.physical_block_size;
1425 }
1426 
1427 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1428 {
1429 	return queue_physical_block_size(bdev_get_queue(bdev));
1430 }
1431 
1432 static inline unsigned int queue_io_min(const struct request_queue *q)
1433 {
1434 	return q->limits.io_min;
1435 }
1436 
1437 static inline int bdev_io_min(struct block_device *bdev)
1438 {
1439 	return queue_io_min(bdev_get_queue(bdev));
1440 }
1441 
1442 static inline unsigned int queue_io_opt(const struct request_queue *q)
1443 {
1444 	return q->limits.io_opt;
1445 }
1446 
1447 static inline int bdev_io_opt(struct block_device *bdev)
1448 {
1449 	return queue_io_opt(bdev_get_queue(bdev));
1450 }
1451 
1452 static inline unsigned int
1453 queue_zone_write_granularity(const struct request_queue *q)
1454 {
1455 	return q->limits.zone_write_granularity;
1456 }
1457 
1458 static inline unsigned int
1459 bdev_zone_write_granularity(struct block_device *bdev)
1460 {
1461 	return queue_zone_write_granularity(bdev_get_queue(bdev));
1462 }
1463 
1464 static inline int queue_alignment_offset(const struct request_queue *q)
1465 {
1466 	if (q->limits.misaligned)
1467 		return -1;
1468 
1469 	return q->limits.alignment_offset;
1470 }
1471 
1472 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1473 {
1474 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1475 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1476 		<< SECTOR_SHIFT;
1477 
1478 	return (granularity + lim->alignment_offset - alignment) % granularity;
1479 }
1480 
1481 static inline int bdev_alignment_offset(struct block_device *bdev)
1482 {
1483 	struct request_queue *q = bdev_get_queue(bdev);
1484 
1485 	if (q->limits.misaligned)
1486 		return -1;
1487 	if (bdev_is_partition(bdev))
1488 		return queue_limit_alignment_offset(&q->limits,
1489 				bdev->bd_start_sect);
1490 	return q->limits.alignment_offset;
1491 }
1492 
1493 static inline int queue_discard_alignment(const struct request_queue *q)
1494 {
1495 	if (q->limits.discard_misaligned)
1496 		return -1;
1497 
1498 	return q->limits.discard_alignment;
1499 }
1500 
1501 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1502 {
1503 	unsigned int alignment, granularity, offset;
1504 
1505 	if (!lim->max_discard_sectors)
1506 		return 0;
1507 
1508 	/* Why are these in bytes, not sectors? */
1509 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
1510 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
1511 	if (!granularity)
1512 		return 0;
1513 
1514 	/* Offset of the partition start in 'granularity' sectors */
1515 	offset = sector_div(sector, granularity);
1516 
1517 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
1518 	offset = (granularity + alignment - offset) % granularity;
1519 
1520 	/* Turn it back into bytes, gaah */
1521 	return offset << SECTOR_SHIFT;
1522 }
1523 
1524 static inline int bdev_discard_alignment(struct block_device *bdev)
1525 {
1526 	struct request_queue *q = bdev_get_queue(bdev);
1527 
1528 	if (bdev_is_partition(bdev))
1529 		return queue_limit_discard_alignment(&q->limits,
1530 				bdev->bd_start_sect);
1531 	return q->limits.discard_alignment;
1532 }
1533 
1534 static inline unsigned int bdev_write_same(struct block_device *bdev)
1535 {
1536 	struct request_queue *q = bdev_get_queue(bdev);
1537 
1538 	if (q)
1539 		return q->limits.max_write_same_sectors;
1540 
1541 	return 0;
1542 }
1543 
1544 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1545 {
1546 	struct request_queue *q = bdev_get_queue(bdev);
1547 
1548 	if (q)
1549 		return q->limits.max_write_zeroes_sectors;
1550 
1551 	return 0;
1552 }
1553 
1554 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1555 {
1556 	struct request_queue *q = bdev_get_queue(bdev);
1557 
1558 	if (q)
1559 		return blk_queue_zoned_model(q);
1560 
1561 	return BLK_ZONED_NONE;
1562 }
1563 
1564 static inline bool bdev_is_zoned(struct block_device *bdev)
1565 {
1566 	struct request_queue *q = bdev_get_queue(bdev);
1567 
1568 	if (q)
1569 		return blk_queue_is_zoned(q);
1570 
1571 	return false;
1572 }
1573 
1574 static inline sector_t bdev_zone_sectors(struct block_device *bdev)
1575 {
1576 	struct request_queue *q = bdev_get_queue(bdev);
1577 
1578 	if (q)
1579 		return blk_queue_zone_sectors(q);
1580 	return 0;
1581 }
1582 
1583 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
1584 {
1585 	struct request_queue *q = bdev_get_queue(bdev);
1586 
1587 	if (q)
1588 		return queue_max_open_zones(q);
1589 	return 0;
1590 }
1591 
1592 static inline unsigned int bdev_max_active_zones(struct block_device *bdev)
1593 {
1594 	struct request_queue *q = bdev_get_queue(bdev);
1595 
1596 	if (q)
1597 		return queue_max_active_zones(q);
1598 	return 0;
1599 }
1600 
1601 static inline int queue_dma_alignment(const struct request_queue *q)
1602 {
1603 	return q ? q->dma_alignment : 511;
1604 }
1605 
1606 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1607 				 unsigned int len)
1608 {
1609 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1610 	return !(addr & alignment) && !(len & alignment);
1611 }
1612 
1613 /* assumes size > 256 */
1614 static inline unsigned int blksize_bits(unsigned int size)
1615 {
1616 	unsigned int bits = 8;
1617 	do {
1618 		bits++;
1619 		size >>= 1;
1620 	} while (size > 256);
1621 	return bits;
1622 }
1623 
1624 static inline unsigned int block_size(struct block_device *bdev)
1625 {
1626 	return 1 << bdev->bd_inode->i_blkbits;
1627 }
1628 
1629 int kblockd_schedule_work(struct work_struct *work);
1630 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1631 
1632 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1633 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1634 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1635 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1636 
1637 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1638 
1639 enum blk_integrity_flags {
1640 	BLK_INTEGRITY_VERIFY		= 1 << 0,
1641 	BLK_INTEGRITY_GENERATE		= 1 << 1,
1642 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
1643 	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
1644 };
1645 
1646 struct blk_integrity_iter {
1647 	void			*prot_buf;
1648 	void			*data_buf;
1649 	sector_t		seed;
1650 	unsigned int		data_size;
1651 	unsigned short		interval;
1652 	const char		*disk_name;
1653 };
1654 
1655 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1656 typedef void (integrity_prepare_fn) (struct request *);
1657 typedef void (integrity_complete_fn) (struct request *, unsigned int);
1658 
1659 struct blk_integrity_profile {
1660 	integrity_processing_fn		*generate_fn;
1661 	integrity_processing_fn		*verify_fn;
1662 	integrity_prepare_fn		*prepare_fn;
1663 	integrity_complete_fn		*complete_fn;
1664 	const char			*name;
1665 };
1666 
1667 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1668 extern void blk_integrity_unregister(struct gendisk *);
1669 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1670 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1671 				   struct scatterlist *);
1672 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1673 
1674 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1675 {
1676 	struct blk_integrity *bi = &disk->queue->integrity;
1677 
1678 	if (!bi->profile)
1679 		return NULL;
1680 
1681 	return bi;
1682 }
1683 
1684 static inline
1685 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1686 {
1687 	return blk_get_integrity(bdev->bd_disk);
1688 }
1689 
1690 static inline bool
1691 blk_integrity_queue_supports_integrity(struct request_queue *q)
1692 {
1693 	return q->integrity.profile;
1694 }
1695 
1696 static inline bool blk_integrity_rq(struct request *rq)
1697 {
1698 	return rq->cmd_flags & REQ_INTEGRITY;
1699 }
1700 
1701 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1702 						    unsigned int segs)
1703 {
1704 	q->limits.max_integrity_segments = segs;
1705 }
1706 
1707 static inline unsigned short
1708 queue_max_integrity_segments(const struct request_queue *q)
1709 {
1710 	return q->limits.max_integrity_segments;
1711 }
1712 
1713 /**
1714  * bio_integrity_intervals - Return number of integrity intervals for a bio
1715  * @bi:		blk_integrity profile for device
1716  * @sectors:	Size of the bio in 512-byte sectors
1717  *
1718  * Description: The block layer calculates everything in 512 byte
1719  * sectors but integrity metadata is done in terms of the data integrity
1720  * interval size of the storage device.  Convert the block layer sectors
1721  * to the appropriate number of integrity intervals.
1722  */
1723 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1724 						   unsigned int sectors)
1725 {
1726 	return sectors >> (bi->interval_exp - 9);
1727 }
1728 
1729 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1730 					       unsigned int sectors)
1731 {
1732 	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
1733 }
1734 
1735 /*
1736  * Return the first bvec that contains integrity data.  Only drivers that are
1737  * limited to a single integrity segment should use this helper.
1738  */
1739 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1740 {
1741 	if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
1742 		return NULL;
1743 	return rq->bio->bi_integrity->bip_vec;
1744 }
1745 
1746 #else /* CONFIG_BLK_DEV_INTEGRITY */
1747 
1748 struct bio;
1749 struct block_device;
1750 struct gendisk;
1751 struct blk_integrity;
1752 
1753 static inline int blk_integrity_rq(struct request *rq)
1754 {
1755 	return 0;
1756 }
1757 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1758 					    struct bio *b)
1759 {
1760 	return 0;
1761 }
1762 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1763 					  struct bio *b,
1764 					  struct scatterlist *s)
1765 {
1766 	return 0;
1767 }
1768 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1769 {
1770 	return NULL;
1771 }
1772 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1773 {
1774 	return NULL;
1775 }
1776 static inline bool
1777 blk_integrity_queue_supports_integrity(struct request_queue *q)
1778 {
1779 	return false;
1780 }
1781 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1782 {
1783 	return 0;
1784 }
1785 static inline void blk_integrity_register(struct gendisk *d,
1786 					 struct blk_integrity *b)
1787 {
1788 }
1789 static inline void blk_integrity_unregister(struct gendisk *d)
1790 {
1791 }
1792 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1793 						    unsigned int segs)
1794 {
1795 }
1796 static inline unsigned short queue_max_integrity_segments(const struct request_queue *q)
1797 {
1798 	return 0;
1799 }
1800 
1801 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1802 						   unsigned int sectors)
1803 {
1804 	return 0;
1805 }
1806 
1807 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1808 					       unsigned int sectors)
1809 {
1810 	return 0;
1811 }
1812 
1813 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1814 {
1815 	return NULL;
1816 }
1817 
1818 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1819 
1820 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1821 
1822 bool blk_ksm_register(struct blk_keyslot_manager *ksm, struct request_queue *q);
1823 
1824 void blk_ksm_unregister(struct request_queue *q);
1825 
1826 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1827 
1828 static inline bool blk_ksm_register(struct blk_keyslot_manager *ksm,
1829 				    struct request_queue *q)
1830 {
1831 	return true;
1832 }
1833 
1834 static inline void blk_ksm_unregister(struct request_queue *q) { }
1835 
1836 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
1837 
1838 
1839 struct block_device_operations {
1840 	blk_qc_t (*submit_bio) (struct bio *bio);
1841 	int (*open) (struct block_device *, fmode_t);
1842 	void (*release) (struct gendisk *, fmode_t);
1843 	int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
1844 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1845 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1846 	unsigned int (*check_events) (struct gendisk *disk,
1847 				      unsigned int clearing);
1848 	void (*unlock_native_capacity) (struct gendisk *);
1849 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1850 	int (*set_read_only)(struct block_device *bdev, bool ro);
1851 	/* this callback is with swap_lock and sometimes page table lock held */
1852 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1853 	int (*report_zones)(struct gendisk *, sector_t sector,
1854 			unsigned int nr_zones, report_zones_cb cb, void *data);
1855 	char *(*devnode)(struct gendisk *disk, umode_t *mode);
1856 	struct module *owner;
1857 	const struct pr_ops *pr_ops;
1858 };
1859 
1860 #ifdef CONFIG_COMPAT
1861 extern int blkdev_compat_ptr_ioctl(struct block_device *, fmode_t,
1862 				      unsigned int, unsigned long);
1863 #else
1864 #define blkdev_compat_ptr_ioctl NULL
1865 #endif
1866 
1867 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1868 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1869 						struct writeback_control *);
1870 
1871 #ifdef CONFIG_BLK_DEV_ZONED
1872 bool blk_req_needs_zone_write_lock(struct request *rq);
1873 bool blk_req_zone_write_trylock(struct request *rq);
1874 void __blk_req_zone_write_lock(struct request *rq);
1875 void __blk_req_zone_write_unlock(struct request *rq);
1876 
1877 static inline void blk_req_zone_write_lock(struct request *rq)
1878 {
1879 	if (blk_req_needs_zone_write_lock(rq))
1880 		__blk_req_zone_write_lock(rq);
1881 }
1882 
1883 static inline void blk_req_zone_write_unlock(struct request *rq)
1884 {
1885 	if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
1886 		__blk_req_zone_write_unlock(rq);
1887 }
1888 
1889 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1890 {
1891 	return rq->q->seq_zones_wlock &&
1892 		test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
1893 }
1894 
1895 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1896 {
1897 	if (!blk_req_needs_zone_write_lock(rq))
1898 		return true;
1899 	return !blk_req_zone_is_write_locked(rq);
1900 }
1901 #else
1902 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
1903 {
1904 	return false;
1905 }
1906 
1907 static inline void blk_req_zone_write_lock(struct request *rq)
1908 {
1909 }
1910 
1911 static inline void blk_req_zone_write_unlock(struct request *rq)
1912 {
1913 }
1914 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1915 {
1916 	return false;
1917 }
1918 
1919 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1920 {
1921 	return true;
1922 }
1923 #endif /* CONFIG_BLK_DEV_ZONED */
1924 
1925 static inline void blk_wake_io_task(struct task_struct *waiter)
1926 {
1927 	/*
1928 	 * If we're polling, the task itself is doing the completions. For
1929 	 * that case, we don't need to signal a wakeup, it's enough to just
1930 	 * mark us as RUNNING.
1931 	 */
1932 	if (waiter == current)
1933 		__set_current_state(TASK_RUNNING);
1934 	else
1935 		wake_up_process(waiter);
1936 }
1937 
1938 unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
1939 		unsigned int op);
1940 void disk_end_io_acct(struct gendisk *disk, unsigned int op,
1941 		unsigned long start_time);
1942 
1943 unsigned long bio_start_io_acct(struct bio *bio);
1944 void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time,
1945 		struct block_device *orig_bdev);
1946 
1947 /**
1948  * bio_end_io_acct - end I/O accounting for bio based drivers
1949  * @bio:	bio to end account for
1950  * @start:	start time returned by bio_start_io_acct()
1951  */
1952 static inline void bio_end_io_acct(struct bio *bio, unsigned long start_time)
1953 {
1954 	return bio_end_io_acct_remapped(bio, start_time, bio->bi_bdev);
1955 }
1956 
1957 int bdev_read_only(struct block_device *bdev);
1958 int set_blocksize(struct block_device *bdev, int size);
1959 
1960 const char *bdevname(struct block_device *bdev, char *buffer);
1961 int lookup_bdev(const char *pathname, dev_t *dev);
1962 
1963 void blkdev_show(struct seq_file *seqf, off_t offset);
1964 
1965 #define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
1966 #define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
1967 #ifdef CONFIG_BLOCK
1968 #define BLKDEV_MAJOR_MAX	512
1969 #else
1970 #define BLKDEV_MAJOR_MAX	0
1971 #endif
1972 
1973 struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
1974 		void *holder);
1975 struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
1976 int bd_prepare_to_claim(struct block_device *bdev, void *holder);
1977 void bd_abort_claiming(struct block_device *bdev, void *holder);
1978 void blkdev_put(struct block_device *bdev, fmode_t mode);
1979 
1980 /* just for blk-cgroup, don't use elsewhere */
1981 struct block_device *blkdev_get_no_open(dev_t dev);
1982 void blkdev_put_no_open(struct block_device *bdev);
1983 
1984 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
1985 void bdev_add(struct block_device *bdev, dev_t dev);
1986 struct block_device *I_BDEV(struct inode *inode);
1987 struct block_device *bdgrab(struct block_device *bdev);
1988 void bdput(struct block_device *);
1989 int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart,
1990 		loff_t lend);
1991 
1992 #ifdef CONFIG_BLOCK
1993 void invalidate_bdev(struct block_device *bdev);
1994 int sync_blockdev(struct block_device *bdev);
1995 #else
1996 static inline void invalidate_bdev(struct block_device *bdev)
1997 {
1998 }
1999 static inline int sync_blockdev(struct block_device *bdev)
2000 {
2001 	return 0;
2002 }
2003 #endif
2004 int fsync_bdev(struct block_device *bdev);
2005 
2006 int freeze_bdev(struct block_device *bdev);
2007 int thaw_bdev(struct block_device *bdev);
2008 
2009 #endif /* _LINUX_BLKDEV_H */
2010