xref: /linux-6.15/include/linux/blkdev.h (revision ebd09753)
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 
8 #ifdef CONFIG_BLOCK
9 
10 #include <linux/major.h>
11 #include <linux/genhd.h>
12 #include <linux/list.h>
13 #include <linux/llist.h>
14 #include <linux/timer.h>
15 #include <linux/workqueue.h>
16 #include <linux/pagemap.h>
17 #include <linux/backing-dev-defs.h>
18 #include <linux/wait.h>
19 #include <linux/mempool.h>
20 #include <linux/pfn.h>
21 #include <linux/bio.h>
22 #include <linux/stringify.h>
23 #include <linux/gfp.h>
24 #include <linux/bsg.h>
25 #include <linux/smp.h>
26 #include <linux/rcupdate.h>
27 #include <linux/percpu-refcount.h>
28 #include <linux/scatterlist.h>
29 #include <linux/blkzoned.h>
30 
31 struct module;
32 struct scsi_ioctl_command;
33 
34 struct request_queue;
35 struct elevator_queue;
36 struct blk_trace;
37 struct request;
38 struct sg_io_hdr;
39 struct bsg_job;
40 struct blkcg_gq;
41 struct blk_flush_queue;
42 struct pr_ops;
43 struct rq_qos;
44 struct blk_queue_stats;
45 struct blk_stat_callback;
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 /*
54  * Maximum number of blkcg policies allowed to be registered concurrently.
55  * Defined here to simplify include dependency.
56  */
57 #define BLKCG_MAX_POLS		5
58 
59 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
60 
61 #define BLK_RL_SYNCFULL		(1U << 0)
62 #define BLK_RL_ASYNCFULL	(1U << 1)
63 
64 struct request_list {
65 	struct request_queue	*q;	/* the queue this rl belongs to */
66 #ifdef CONFIG_BLK_CGROUP
67 	struct blkcg_gq		*blkg;	/* blkg this request pool belongs to */
68 #endif
69 	/*
70 	 * count[], starved[], and wait[] are indexed by
71 	 * BLK_RW_SYNC/BLK_RW_ASYNC
72 	 */
73 	int			count[2];
74 	int			starved[2];
75 	mempool_t		*rq_pool;
76 	wait_queue_head_t	wait[2];
77 	unsigned int		flags;
78 };
79 
80 /*
81  * request flags */
82 typedef __u32 __bitwise req_flags_t;
83 
84 /* elevator knows about this request */
85 #define RQF_SORTED		((__force req_flags_t)(1 << 0))
86 /* drive already may have started this one */
87 #define RQF_STARTED		((__force req_flags_t)(1 << 1))
88 /* uses tagged queueing */
89 #define RQF_QUEUED		((__force req_flags_t)(1 << 2))
90 /* may not be passed by ioscheduler */
91 #define RQF_SOFTBARRIER		((__force req_flags_t)(1 << 3))
92 /* request for flush sequence */
93 #define RQF_FLUSH_SEQ		((__force req_flags_t)(1 << 4))
94 /* merge of different types, fail separately */
95 #define RQF_MIXED_MERGE		((__force req_flags_t)(1 << 5))
96 /* track inflight for MQ */
97 #define RQF_MQ_INFLIGHT		((__force req_flags_t)(1 << 6))
98 /* don't call prep for this one */
99 #define RQF_DONTPREP		((__force req_flags_t)(1 << 7))
100 /* set for "ide_preempt" requests and also for requests for which the SCSI
101    "quiesce" state must be ignored. */
102 #define RQF_PREEMPT		((__force req_flags_t)(1 << 8))
103 /* contains copies of user pages */
104 #define RQF_COPY_USER		((__force req_flags_t)(1 << 9))
105 /* vaguely specified driver internal error.  Ignored by the block layer */
106 #define RQF_FAILED		((__force req_flags_t)(1 << 10))
107 /* don't warn about errors */
108 #define RQF_QUIET		((__force req_flags_t)(1 << 11))
109 /* elevator private data attached */
110 #define RQF_ELVPRIV		((__force req_flags_t)(1 << 12))
111 /* account into disk and partition IO statistics */
112 #define RQF_IO_STAT		((__force req_flags_t)(1 << 13))
113 /* request came from our alloc pool */
114 #define RQF_ALLOCED		((__force req_flags_t)(1 << 14))
115 /* runtime pm request */
116 #define RQF_PM			((__force req_flags_t)(1 << 15))
117 /* on IO scheduler merge hash */
118 #define RQF_HASHED		((__force req_flags_t)(1 << 16))
119 /* track IO completion time */
120 #define RQF_STATS		((__force req_flags_t)(1 << 17))
121 /* Look at ->special_vec for the actual data payload instead of the
122    bio chain. */
123 #define RQF_SPECIAL_PAYLOAD	((__force req_flags_t)(1 << 18))
124 /* The per-zone write lock is held for this request */
125 #define RQF_ZONE_WRITE_LOCKED	((__force req_flags_t)(1 << 19))
126 /* already slept for hybrid poll */
127 #define RQF_MQ_POLL_SLEPT	((__force req_flags_t)(1 << 20))
128 /* ->timeout has been called, don't expire again */
129 #define RQF_TIMED_OUT		((__force req_flags_t)(1 << 21))
130 
131 /* flags that prevent us from merging requests: */
132 #define RQF_NOMERGE_FLAGS \
133 	(RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
134 
135 /*
136  * Request state for blk-mq.
137  */
138 enum mq_rq_state {
139 	MQ_RQ_IDLE		= 0,
140 	MQ_RQ_IN_FLIGHT		= 1,
141 	MQ_RQ_COMPLETE		= 2,
142 };
143 
144 /*
145  * Try to put the fields that are referenced together in the same cacheline.
146  *
147  * If you modify this structure, make sure to update blk_rq_init() and
148  * especially blk_mq_rq_ctx_init() to take care of the added fields.
149  */
150 struct request {
151 	struct request_queue *q;
152 	struct blk_mq_ctx *mq_ctx;
153 
154 	int cpu;
155 	unsigned int cmd_flags;		/* op and common flags */
156 	req_flags_t rq_flags;
157 
158 	int internal_tag;
159 
160 	/* the following two fields are internal, NEVER access directly */
161 	unsigned int __data_len;	/* total data len */
162 	int tag;
163 	sector_t __sector;		/* sector cursor */
164 
165 	struct bio *bio;
166 	struct bio *biotail;
167 
168 	struct list_head queuelist;
169 
170 	/*
171 	 * The hash is used inside the scheduler, and killed once the
172 	 * request reaches the dispatch list. The ipi_list is only used
173 	 * to queue the request for softirq completion, which is long
174 	 * after the request has been unhashed (and even removed from
175 	 * the dispatch list).
176 	 */
177 	union {
178 		struct hlist_node hash;	/* merge hash */
179 		struct list_head ipi_list;
180 	};
181 
182 	/*
183 	 * The rb_node is only used inside the io scheduler, requests
184 	 * are pruned when moved to the dispatch queue. So let the
185 	 * completion_data share space with the rb_node.
186 	 */
187 	union {
188 		struct rb_node rb_node;	/* sort/lookup */
189 		struct bio_vec special_vec;
190 		void *completion_data;
191 		int error_count; /* for legacy drivers, don't use */
192 	};
193 
194 	/*
195 	 * Three pointers are available for the IO schedulers, if they need
196 	 * more they have to dynamically allocate it.  Flush requests are
197 	 * never put on the IO scheduler. So let the flush fields share
198 	 * space with the elevator data.
199 	 */
200 	union {
201 		struct {
202 			struct io_cq		*icq;
203 			void			*priv[2];
204 		} elv;
205 
206 		struct {
207 			unsigned int		seq;
208 			struct list_head	list;
209 			rq_end_io_fn		*saved_end_io;
210 		} flush;
211 	};
212 
213 	struct gendisk *rq_disk;
214 	struct hd_struct *part;
215 	/* Time that I/O was submitted to the kernel. */
216 	u64 start_time_ns;
217 	/* Time that I/O was submitted to the device. */
218 	u64 io_start_time_ns;
219 
220 #ifdef CONFIG_BLK_WBT
221 	unsigned short wbt_flags;
222 #endif
223 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
224 	unsigned short throtl_size;
225 #endif
226 
227 	/*
228 	 * Number of scatter-gather DMA addr+len pairs after
229 	 * physical address coalescing is performed.
230 	 */
231 	unsigned short nr_phys_segments;
232 
233 #if defined(CONFIG_BLK_DEV_INTEGRITY)
234 	unsigned short nr_integrity_segments;
235 #endif
236 
237 	unsigned short write_hint;
238 	unsigned short ioprio;
239 
240 	void *special;		/* opaque pointer available for LLD use */
241 
242 	unsigned int extra_len;	/* length of alignment and padding */
243 
244 	enum mq_rq_state state;
245 	refcount_t ref;
246 
247 	unsigned int timeout;
248 
249 	/* access through blk_rq_set_deadline, blk_rq_deadline */
250 	unsigned long __deadline;
251 
252 	struct list_head timeout_list;
253 
254 	union {
255 		struct __call_single_data csd;
256 		u64 fifo_time;
257 	};
258 
259 	/*
260 	 * completion callback.
261 	 */
262 	rq_end_io_fn *end_io;
263 	void *end_io_data;
264 
265 	/* for bidi */
266 	struct request *next_rq;
267 
268 #ifdef CONFIG_BLK_CGROUP
269 	struct request_list *rl;		/* rl this rq is alloced from */
270 #endif
271 };
272 
273 static inline bool blk_op_is_scsi(unsigned int op)
274 {
275 	return op == REQ_OP_SCSI_IN || op == REQ_OP_SCSI_OUT;
276 }
277 
278 static inline bool blk_op_is_private(unsigned int op)
279 {
280 	return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
281 }
282 
283 static inline bool blk_rq_is_scsi(struct request *rq)
284 {
285 	return blk_op_is_scsi(req_op(rq));
286 }
287 
288 static inline bool blk_rq_is_private(struct request *rq)
289 {
290 	return blk_op_is_private(req_op(rq));
291 }
292 
293 static inline bool blk_rq_is_passthrough(struct request *rq)
294 {
295 	return blk_rq_is_scsi(rq) || blk_rq_is_private(rq);
296 }
297 
298 static inline bool bio_is_passthrough(struct bio *bio)
299 {
300 	unsigned op = bio_op(bio);
301 
302 	return blk_op_is_scsi(op) || blk_op_is_private(op);
303 }
304 
305 static inline unsigned short req_get_ioprio(struct request *req)
306 {
307 	return req->ioprio;
308 }
309 
310 #include <linux/elevator.h>
311 
312 struct blk_queue_ctx;
313 
314 typedef void (request_fn_proc) (struct request_queue *q);
315 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
316 typedef bool (poll_q_fn) (struct request_queue *q, blk_qc_t);
317 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
318 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
319 
320 struct bio_vec;
321 typedef void (softirq_done_fn)(struct request *);
322 typedef int (dma_drain_needed_fn)(struct request *);
323 typedef int (lld_busy_fn) (struct request_queue *q);
324 typedef int (bsg_job_fn) (struct bsg_job *);
325 typedef int (init_rq_fn)(struct request_queue *, struct request *, gfp_t);
326 typedef void (exit_rq_fn)(struct request_queue *, struct request *);
327 
328 enum blk_eh_timer_return {
329 	BLK_EH_DONE,		/* drivers has completed the command */
330 	BLK_EH_RESET_TIMER,	/* reset timer and try again */
331 };
332 
333 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
334 
335 enum blk_queue_state {
336 	Queue_down,
337 	Queue_up,
338 };
339 
340 struct blk_queue_tag {
341 	struct request **tag_index;	/* map of busy tags */
342 	unsigned long *tag_map;		/* bit map of free/busy tags */
343 	int max_depth;			/* what we will send to device */
344 	int real_max_depth;		/* what the array can hold */
345 	atomic_t refcnt;		/* map can be shared */
346 	int alloc_policy;		/* tag allocation policy */
347 	int next_tag;			/* next tag */
348 };
349 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
350 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
351 
352 #define BLK_SCSI_MAX_CMDS	(256)
353 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
354 
355 /*
356  * Zoned block device models (zoned limit).
357  */
358 enum blk_zoned_model {
359 	BLK_ZONED_NONE,	/* Regular block device */
360 	BLK_ZONED_HA,	/* Host-aware zoned block device */
361 	BLK_ZONED_HM,	/* Host-managed zoned block device */
362 };
363 
364 struct queue_limits {
365 	unsigned long		bounce_pfn;
366 	unsigned long		seg_boundary_mask;
367 	unsigned long		virt_boundary_mask;
368 
369 	unsigned int		max_hw_sectors;
370 	unsigned int		max_dev_sectors;
371 	unsigned int		chunk_sectors;
372 	unsigned int		max_sectors;
373 	unsigned int		max_segment_size;
374 	unsigned int		physical_block_size;
375 	unsigned int		alignment_offset;
376 	unsigned int		io_min;
377 	unsigned int		io_opt;
378 	unsigned int		max_discard_sectors;
379 	unsigned int		max_hw_discard_sectors;
380 	unsigned int		max_write_same_sectors;
381 	unsigned int		max_write_zeroes_sectors;
382 	unsigned int		discard_granularity;
383 	unsigned int		discard_alignment;
384 
385 	unsigned short		logical_block_size;
386 	unsigned short		max_segments;
387 	unsigned short		max_integrity_segments;
388 	unsigned short		max_discard_segments;
389 
390 	unsigned char		misaligned;
391 	unsigned char		discard_misaligned;
392 	unsigned char		cluster;
393 	unsigned char		raid_partial_stripes_expensive;
394 	enum blk_zoned_model	zoned;
395 };
396 
397 #ifdef CONFIG_BLK_DEV_ZONED
398 
399 extern unsigned int blkdev_nr_zones(struct block_device *bdev);
400 extern int blkdev_report_zones(struct block_device *bdev,
401 			       sector_t sector, struct blk_zone *zones,
402 			       unsigned int *nr_zones, gfp_t gfp_mask);
403 extern int blkdev_reset_zones(struct block_device *bdev, sector_t sectors,
404 			      sector_t nr_sectors, gfp_t gfp_mask);
405 extern int blk_revalidate_disk_zones(struct gendisk *disk);
406 
407 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
408 				     unsigned int cmd, unsigned long arg);
409 extern int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
410 				    unsigned int cmd, unsigned long arg);
411 
412 #else /* CONFIG_BLK_DEV_ZONED */
413 
414 static inline unsigned int blkdev_nr_zones(struct block_device *bdev)
415 {
416 	return 0;
417 }
418 
419 static inline int blk_revalidate_disk_zones(struct gendisk *disk)
420 {
421 	return 0;
422 }
423 
424 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
425 					    fmode_t mode, unsigned int cmd,
426 					    unsigned long arg)
427 {
428 	return -ENOTTY;
429 }
430 
431 static inline int blkdev_reset_zones_ioctl(struct block_device *bdev,
432 					   fmode_t mode, unsigned int cmd,
433 					   unsigned long arg)
434 {
435 	return -ENOTTY;
436 }
437 
438 #endif /* CONFIG_BLK_DEV_ZONED */
439 
440 struct request_queue {
441 	/*
442 	 * Together with queue_head for cacheline sharing
443 	 */
444 	struct list_head	queue_head;
445 	struct request		*last_merge;
446 	struct elevator_queue	*elevator;
447 	int			nr_rqs[2];	/* # allocated [a]sync rqs */
448 	int			nr_rqs_elvpriv;	/* # allocated rqs w/ elvpriv */
449 
450 	struct blk_queue_stats	*stats;
451 	struct rq_qos		*rq_qos;
452 
453 	/*
454 	 * If blkcg is not used, @q->root_rl serves all requests.  If blkcg
455 	 * is used, root blkg allocates from @q->root_rl and all other
456 	 * blkgs from their own blkg->rl.  Which one to use should be
457 	 * determined using bio_request_list().
458 	 */
459 	struct request_list	root_rl;
460 
461 	request_fn_proc		*request_fn;
462 	make_request_fn		*make_request_fn;
463 	poll_q_fn		*poll_fn;
464 	prep_rq_fn		*prep_rq_fn;
465 	unprep_rq_fn		*unprep_rq_fn;
466 	softirq_done_fn		*softirq_done_fn;
467 	rq_timed_out_fn		*rq_timed_out_fn;
468 	dma_drain_needed_fn	*dma_drain_needed;
469 	lld_busy_fn		*lld_busy_fn;
470 	/* Called just after a request is allocated */
471 	init_rq_fn		*init_rq_fn;
472 	/* Called just before a request is freed */
473 	exit_rq_fn		*exit_rq_fn;
474 	/* Called from inside blk_get_request() */
475 	void (*initialize_rq_fn)(struct request *rq);
476 
477 	const struct blk_mq_ops	*mq_ops;
478 
479 	unsigned int		*mq_map;
480 
481 	/* sw queues */
482 	struct blk_mq_ctx __percpu	*queue_ctx;
483 	unsigned int		nr_queues;
484 
485 	unsigned int		queue_depth;
486 
487 	/* hw dispatch queues */
488 	struct blk_mq_hw_ctx	**queue_hw_ctx;
489 	unsigned int		nr_hw_queues;
490 
491 	/*
492 	 * Dispatch queue sorting
493 	 */
494 	sector_t		end_sector;
495 	struct request		*boundary_rq;
496 
497 	/*
498 	 * Delayed queue handling
499 	 */
500 	struct delayed_work	delay_work;
501 
502 	struct backing_dev_info	*backing_dev_info;
503 
504 	/*
505 	 * The queue owner gets to use this for whatever they like.
506 	 * ll_rw_blk doesn't touch it.
507 	 */
508 	void			*queuedata;
509 
510 	/*
511 	 * various queue flags, see QUEUE_* below
512 	 */
513 	unsigned long		queue_flags;
514 	/*
515 	 * Number of contexts that have called blk_set_pm_only(). If this
516 	 * counter is above zero then only RQF_PM and RQF_PREEMPT requests are
517 	 * processed.
518 	 */
519 	atomic_t		pm_only;
520 
521 	/*
522 	 * ida allocated id for this queue.  Used to index queues from
523 	 * ioctx.
524 	 */
525 	int			id;
526 
527 	/*
528 	 * queue needs bounce pages for pages above this limit
529 	 */
530 	gfp_t			bounce_gfp;
531 
532 	/*
533 	 * protects queue structures from reentrancy. ->__queue_lock should
534 	 * _never_ be used directly, it is queue private. always use
535 	 * ->queue_lock.
536 	 */
537 	spinlock_t		__queue_lock;
538 	spinlock_t		*queue_lock;
539 
540 	/*
541 	 * queue kobject
542 	 */
543 	struct kobject kobj;
544 
545 	/*
546 	 * mq queue kobject
547 	 */
548 	struct kobject mq_kobj;
549 
550 #ifdef  CONFIG_BLK_DEV_INTEGRITY
551 	struct blk_integrity integrity;
552 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
553 
554 #ifdef CONFIG_PM
555 	struct device		*dev;
556 	int			rpm_status;
557 	unsigned int		nr_pending;
558 #endif
559 
560 	/*
561 	 * queue settings
562 	 */
563 	unsigned long		nr_requests;	/* Max # of requests */
564 	unsigned int		nr_congestion_on;
565 	unsigned int		nr_congestion_off;
566 	unsigned int		nr_batching;
567 
568 	unsigned int		dma_drain_size;
569 	void			*dma_drain_buffer;
570 	unsigned int		dma_pad_mask;
571 	unsigned int		dma_alignment;
572 
573 	struct blk_queue_tag	*queue_tags;
574 
575 	unsigned int		nr_sorted;
576 	unsigned int		in_flight[2];
577 
578 	/*
579 	 * Number of active block driver functions for which blk_drain_queue()
580 	 * must wait. Must be incremented around functions that unlock the
581 	 * queue_lock internally, e.g. scsi_request_fn().
582 	 */
583 	unsigned int		request_fn_active;
584 
585 	unsigned int		rq_timeout;
586 	int			poll_nsec;
587 
588 	struct blk_stat_callback	*poll_cb;
589 	struct blk_rq_stat	poll_stat[BLK_MQ_POLL_STATS_BKTS];
590 
591 	struct timer_list	timeout;
592 	struct work_struct	timeout_work;
593 	struct list_head	timeout_list;
594 
595 	struct list_head	icq_list;
596 #ifdef CONFIG_BLK_CGROUP
597 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
598 	struct blkcg_gq		*root_blkg;
599 	struct list_head	blkg_list;
600 #endif
601 
602 	struct queue_limits	limits;
603 
604 #ifdef CONFIG_BLK_DEV_ZONED
605 	/*
606 	 * Zoned block device information for request dispatch control.
607 	 * nr_zones is the total number of zones of the device. This is always
608 	 * 0 for regular block devices. seq_zones_bitmap is a bitmap of nr_zones
609 	 * bits which indicates if a zone is conventional (bit clear) or
610 	 * sequential (bit set). seq_zones_wlock is a bitmap of nr_zones
611 	 * bits which indicates if a zone is write locked, that is, if a write
612 	 * request targeting the zone was dispatched. All three fields are
613 	 * initialized by the low level device driver (e.g. scsi/sd.c).
614 	 * Stacking drivers (device mappers) may or may not initialize
615 	 * these fields.
616 	 *
617 	 * Reads of this information must be protected with blk_queue_enter() /
618 	 * blk_queue_exit(). Modifying this information is only allowed while
619 	 * no requests are being processed. See also blk_mq_freeze_queue() and
620 	 * blk_mq_unfreeze_queue().
621 	 */
622 	unsigned int		nr_zones;
623 	unsigned long		*seq_zones_bitmap;
624 	unsigned long		*seq_zones_wlock;
625 #endif /* CONFIG_BLK_DEV_ZONED */
626 
627 	/*
628 	 * sg stuff
629 	 */
630 	unsigned int		sg_timeout;
631 	unsigned int		sg_reserved_size;
632 	int			node;
633 #ifdef CONFIG_BLK_DEV_IO_TRACE
634 	struct blk_trace	*blk_trace;
635 	struct mutex		blk_trace_mutex;
636 #endif
637 	/*
638 	 * for flush operations
639 	 */
640 	struct blk_flush_queue	*fq;
641 
642 	struct list_head	requeue_list;
643 	spinlock_t		requeue_lock;
644 	struct delayed_work	requeue_work;
645 
646 	struct mutex		sysfs_lock;
647 
648 	int			bypass_depth;
649 	atomic_t		mq_freeze_depth;
650 
651 #if defined(CONFIG_BLK_DEV_BSG)
652 	bsg_job_fn		*bsg_job_fn;
653 	struct bsg_class_device bsg_dev;
654 #endif
655 
656 #ifdef CONFIG_BLK_DEV_THROTTLING
657 	/* Throttle data */
658 	struct throtl_data *td;
659 #endif
660 	struct rcu_head		rcu_head;
661 	wait_queue_head_t	mq_freeze_wq;
662 	struct percpu_ref	q_usage_counter;
663 	struct list_head	all_q_node;
664 
665 	struct blk_mq_tag_set	*tag_set;
666 	struct list_head	tag_set_list;
667 	struct bio_set		bio_split;
668 
669 #ifdef CONFIG_BLK_DEBUG_FS
670 	struct dentry		*debugfs_dir;
671 	struct dentry		*sched_debugfs_dir;
672 #endif
673 
674 	bool			mq_sysfs_init_done;
675 
676 	size_t			cmd_size;
677 	void			*rq_alloc_data;
678 
679 	struct work_struct	release_work;
680 
681 #define BLK_MAX_WRITE_HINTS	5
682 	u64			write_hints[BLK_MAX_WRITE_HINTS];
683 };
684 
685 #define QUEUE_FLAG_QUEUED	0	/* uses generic tag queueing */
686 #define QUEUE_FLAG_STOPPED	1	/* queue is stopped */
687 #define QUEUE_FLAG_DYING	2	/* queue being torn down */
688 #define QUEUE_FLAG_BYPASS	3	/* act as dumb FIFO queue */
689 #define QUEUE_FLAG_BIDI		4	/* queue supports bidi requests */
690 #define QUEUE_FLAG_NOMERGES     5	/* disable merge attempts */
691 #define QUEUE_FLAG_SAME_COMP	6	/* complete on same CPU-group */
692 #define QUEUE_FLAG_FAIL_IO	7	/* fake timeout */
693 #define QUEUE_FLAG_NONROT	9	/* non-rotational device (SSD) */
694 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
695 #define QUEUE_FLAG_IO_STAT     10	/* do disk/partitions IO accounting */
696 #define QUEUE_FLAG_DISCARD     11	/* supports DISCARD */
697 #define QUEUE_FLAG_NOXMERGES   12	/* No extended merges */
698 #define QUEUE_FLAG_ADD_RANDOM  13	/* Contributes to random pool */
699 #define QUEUE_FLAG_SECERASE    14	/* supports secure erase */
700 #define QUEUE_FLAG_SAME_FORCE  15	/* force complete on same CPU */
701 #define QUEUE_FLAG_DEAD        16	/* queue tear-down finished */
702 #define QUEUE_FLAG_INIT_DONE   17	/* queue is initialized */
703 #define QUEUE_FLAG_NO_SG_MERGE 18	/* don't attempt to merge SG segments*/
704 #define QUEUE_FLAG_POLL	       19	/* IO polling enabled if set */
705 #define QUEUE_FLAG_WC	       20	/* Write back caching */
706 #define QUEUE_FLAG_FUA	       21	/* device supports FUA writes */
707 #define QUEUE_FLAG_FLUSH_NQ    22	/* flush not queueuable */
708 #define QUEUE_FLAG_DAX         23	/* device supports DAX */
709 #define QUEUE_FLAG_STATS       24	/* track IO start and completion times */
710 #define QUEUE_FLAG_POLL_STATS  25	/* collecting stats for hybrid polling */
711 #define QUEUE_FLAG_REGISTERED  26	/* queue has been registered to a disk */
712 #define QUEUE_FLAG_SCSI_PASSTHROUGH 27	/* queue supports SCSI commands */
713 #define QUEUE_FLAG_QUIESCED    28	/* queue has been quiesced */
714 #define QUEUE_FLAG_PCI_P2PDMA  29	/* device supports PCI p2p requests */
715 
716 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
717 				 (1 << QUEUE_FLAG_SAME_COMP)	|	\
718 				 (1 << QUEUE_FLAG_ADD_RANDOM))
719 
720 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
721 				 (1 << QUEUE_FLAG_SAME_COMP)	|	\
722 				 (1 << QUEUE_FLAG_POLL))
723 
724 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
725 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
726 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
727 bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q);
728 
729 #define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
730 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
731 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
732 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
733 #define blk_queue_bypass(q)	test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
734 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
735 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
736 #define blk_queue_noxmerges(q)	\
737 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
738 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
739 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
740 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
741 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
742 #define blk_queue_secure_erase(q) \
743 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
744 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
745 #define blk_queue_scsi_passthrough(q)	\
746 	test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
747 #define blk_queue_pci_p2pdma(q)	\
748 	test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
749 
750 #define blk_noretry_request(rq) \
751 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
752 			     REQ_FAILFAST_DRIVER))
753 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
754 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
755 #define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
756 
757 extern void blk_set_pm_only(struct request_queue *q);
758 extern void blk_clear_pm_only(struct request_queue *q);
759 
760 static inline int queue_in_flight(struct request_queue *q)
761 {
762 	return q->in_flight[0] + q->in_flight[1];
763 }
764 
765 static inline bool blk_account_rq(struct request *rq)
766 {
767 	return (rq->rq_flags & RQF_STARTED) && !blk_rq_is_passthrough(rq);
768 }
769 
770 #define blk_rq_cpu_valid(rq)	((rq)->cpu != -1)
771 #define blk_bidi_rq(rq)		((rq)->next_rq != NULL)
772 /* rq->queuelist of dequeued request must be list_empty() */
773 #define blk_queued_rq(rq)	(!list_empty(&(rq)->queuelist))
774 
775 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
776 
777 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
778 
779 /*
780  * Driver can handle struct request, if it either has an old style
781  * request_fn defined, or is blk-mq based.
782  */
783 static inline bool queue_is_rq_based(struct request_queue *q)
784 {
785 	return q->request_fn || q->mq_ops;
786 }
787 
788 static inline unsigned int blk_queue_cluster(struct request_queue *q)
789 {
790 	return q->limits.cluster;
791 }
792 
793 static inline enum blk_zoned_model
794 blk_queue_zoned_model(struct request_queue *q)
795 {
796 	return q->limits.zoned;
797 }
798 
799 static inline bool blk_queue_is_zoned(struct request_queue *q)
800 {
801 	switch (blk_queue_zoned_model(q)) {
802 	case BLK_ZONED_HA:
803 	case BLK_ZONED_HM:
804 		return true;
805 	default:
806 		return false;
807 	}
808 }
809 
810 static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
811 {
812 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
813 }
814 
815 #ifdef CONFIG_BLK_DEV_ZONED
816 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
817 {
818 	return blk_queue_is_zoned(q) ? q->nr_zones : 0;
819 }
820 
821 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
822 					     sector_t sector)
823 {
824 	if (!blk_queue_is_zoned(q))
825 		return 0;
826 	return sector >> ilog2(q->limits.chunk_sectors);
827 }
828 
829 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
830 					 sector_t sector)
831 {
832 	if (!blk_queue_is_zoned(q) || !q->seq_zones_bitmap)
833 		return false;
834 	return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
835 }
836 #else /* CONFIG_BLK_DEV_ZONED */
837 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
838 {
839 	return 0;
840 }
841 #endif /* CONFIG_BLK_DEV_ZONED */
842 
843 static inline bool rq_is_sync(struct request *rq)
844 {
845 	return op_is_sync(rq->cmd_flags);
846 }
847 
848 static inline bool blk_rl_full(struct request_list *rl, bool sync)
849 {
850 	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
851 
852 	return rl->flags & flag;
853 }
854 
855 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
856 {
857 	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
858 
859 	rl->flags |= flag;
860 }
861 
862 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
863 {
864 	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
865 
866 	rl->flags &= ~flag;
867 }
868 
869 static inline bool rq_mergeable(struct request *rq)
870 {
871 	if (blk_rq_is_passthrough(rq))
872 		return false;
873 
874 	if (req_op(rq) == REQ_OP_FLUSH)
875 		return false;
876 
877 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
878 		return false;
879 
880 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
881 		return false;
882 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
883 		return false;
884 
885 	return true;
886 }
887 
888 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
889 {
890 	if (bio_page(a) == bio_page(b) &&
891 	    bio_offset(a) == bio_offset(b))
892 		return true;
893 
894 	return false;
895 }
896 
897 static inline unsigned int blk_queue_depth(struct request_queue *q)
898 {
899 	if (q->queue_depth)
900 		return q->queue_depth;
901 
902 	return q->nr_requests;
903 }
904 
905 /*
906  * q->prep_rq_fn return values
907  */
908 enum {
909 	BLKPREP_OK,		/* serve it */
910 	BLKPREP_KILL,		/* fatal error, kill, return -EIO */
911 	BLKPREP_DEFER,		/* leave on queue */
912 	BLKPREP_INVALID,	/* invalid command, kill, return -EREMOTEIO */
913 };
914 
915 extern unsigned long blk_max_low_pfn, blk_max_pfn;
916 
917 /*
918  * standard bounce addresses:
919  *
920  * BLK_BOUNCE_HIGH	: bounce all highmem pages
921  * BLK_BOUNCE_ANY	: don't bounce anything
922  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
923  */
924 
925 #if BITS_PER_LONG == 32
926 #define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
927 #else
928 #define BLK_BOUNCE_HIGH		-1ULL
929 #endif
930 #define BLK_BOUNCE_ANY		(-1ULL)
931 #define BLK_BOUNCE_ISA		(DMA_BIT_MASK(24))
932 
933 /*
934  * default timeout for SG_IO if none specified
935  */
936 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
937 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
938 
939 struct rq_map_data {
940 	struct page **pages;
941 	int page_order;
942 	int nr_entries;
943 	unsigned long offset;
944 	int null_mapped;
945 	int from_user;
946 };
947 
948 struct req_iterator {
949 	struct bvec_iter iter;
950 	struct bio *bio;
951 };
952 
953 /* This should not be used directly - use rq_for_each_segment */
954 #define for_each_bio(_bio)		\
955 	for (; _bio; _bio = _bio->bi_next)
956 #define __rq_for_each_bio(_bio, rq)	\
957 	if ((rq->bio))			\
958 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
959 
960 #define rq_for_each_segment(bvl, _rq, _iter)			\
961 	__rq_for_each_bio(_iter.bio, _rq)			\
962 		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
963 
964 #define rq_iter_last(bvec, _iter)				\
965 		(_iter.bio->bi_next == NULL &&			\
966 		 bio_iter_last(bvec, _iter.iter))
967 
968 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
969 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
970 #endif
971 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
972 extern void rq_flush_dcache_pages(struct request *rq);
973 #else
974 static inline void rq_flush_dcache_pages(struct request *rq)
975 {
976 }
977 #endif
978 
979 extern int blk_register_queue(struct gendisk *disk);
980 extern void blk_unregister_queue(struct gendisk *disk);
981 extern blk_qc_t generic_make_request(struct bio *bio);
982 extern blk_qc_t direct_make_request(struct bio *bio);
983 extern void blk_rq_init(struct request_queue *q, struct request *rq);
984 extern void blk_init_request_from_bio(struct request *req, struct bio *bio);
985 extern void blk_put_request(struct request *);
986 extern void __blk_put_request(struct request_queue *, struct request *);
987 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
988 				       blk_mq_req_flags_t flags);
989 extern void blk_requeue_request(struct request_queue *, struct request *);
990 extern int blk_lld_busy(struct request_queue *q);
991 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
992 			     struct bio_set *bs, gfp_t gfp_mask,
993 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
994 			     void *data);
995 extern void blk_rq_unprep_clone(struct request *rq);
996 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
997 				     struct request *rq);
998 extern int blk_rq_append_bio(struct request *rq, struct bio **bio);
999 extern void blk_delay_queue(struct request_queue *, unsigned long);
1000 extern void blk_queue_split(struct request_queue *, struct bio **);
1001 extern void blk_recount_segments(struct request_queue *, struct bio *);
1002 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
1003 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
1004 			      unsigned int, void __user *);
1005 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
1006 			  unsigned int, void __user *);
1007 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
1008 			 struct scsi_ioctl_command __user *);
1009 
1010 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
1011 extern void blk_queue_exit(struct request_queue *q);
1012 extern void blk_start_queue(struct request_queue *q);
1013 extern void blk_start_queue_async(struct request_queue *q);
1014 extern void blk_stop_queue(struct request_queue *q);
1015 extern void blk_sync_queue(struct request_queue *q);
1016 extern void __blk_stop_queue(struct request_queue *q);
1017 extern void __blk_run_queue(struct request_queue *q);
1018 extern void __blk_run_queue_uncond(struct request_queue *q);
1019 extern void blk_run_queue(struct request_queue *);
1020 extern void blk_run_queue_async(struct request_queue *q);
1021 extern int blk_rq_map_user(struct request_queue *, struct request *,
1022 			   struct rq_map_data *, void __user *, unsigned long,
1023 			   gfp_t);
1024 extern int blk_rq_unmap_user(struct bio *);
1025 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
1026 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
1027 			       struct rq_map_data *, const struct iov_iter *,
1028 			       gfp_t);
1029 extern void blk_execute_rq(struct request_queue *, struct gendisk *,
1030 			  struct request *, int);
1031 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
1032 				  struct request *, int, rq_end_io_fn *);
1033 
1034 int blk_status_to_errno(blk_status_t status);
1035 blk_status_t errno_to_blk_status(int errno);
1036 
1037 bool blk_poll(struct request_queue *q, blk_qc_t cookie);
1038 
1039 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
1040 {
1041 	return bdev->bd_disk->queue;	/* this is never NULL */
1042 }
1043 
1044 /*
1045  * The basic unit of block I/O is a sector. It is used in a number of contexts
1046  * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
1047  * bytes. Variables of type sector_t represent an offset or size that is a
1048  * multiple of 512 bytes. Hence these two constants.
1049  */
1050 #ifndef SECTOR_SHIFT
1051 #define SECTOR_SHIFT 9
1052 #endif
1053 #ifndef SECTOR_SIZE
1054 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
1055 #endif
1056 
1057 /*
1058  * blk_rq_pos()			: the current sector
1059  * blk_rq_bytes()		: bytes left in the entire request
1060  * blk_rq_cur_bytes()		: bytes left in the current segment
1061  * blk_rq_err_bytes()		: bytes left till the next error boundary
1062  * blk_rq_sectors()		: sectors left in the entire request
1063  * blk_rq_cur_sectors()		: sectors left in the current segment
1064  */
1065 static inline sector_t blk_rq_pos(const struct request *rq)
1066 {
1067 	return rq->__sector;
1068 }
1069 
1070 static inline unsigned int blk_rq_bytes(const struct request *rq)
1071 {
1072 	return rq->__data_len;
1073 }
1074 
1075 static inline int blk_rq_cur_bytes(const struct request *rq)
1076 {
1077 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
1078 }
1079 
1080 extern unsigned int blk_rq_err_bytes(const struct request *rq);
1081 
1082 static inline unsigned int blk_rq_sectors(const struct request *rq)
1083 {
1084 	return blk_rq_bytes(rq) >> SECTOR_SHIFT;
1085 }
1086 
1087 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
1088 {
1089 	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
1090 }
1091 
1092 #ifdef CONFIG_BLK_DEV_ZONED
1093 static inline unsigned int blk_rq_zone_no(struct request *rq)
1094 {
1095 	return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
1096 }
1097 
1098 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
1099 {
1100 	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
1101 }
1102 #endif /* CONFIG_BLK_DEV_ZONED */
1103 
1104 /*
1105  * Some commands like WRITE SAME have a payload or data transfer size which
1106  * is different from the size of the request.  Any driver that supports such
1107  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
1108  * calculate the data transfer size.
1109  */
1110 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
1111 {
1112 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1113 		return rq->special_vec.bv_len;
1114 	return blk_rq_bytes(rq);
1115 }
1116 
1117 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
1118 						     int op)
1119 {
1120 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
1121 		return min(q->limits.max_discard_sectors,
1122 			   UINT_MAX >> SECTOR_SHIFT);
1123 
1124 	if (unlikely(op == REQ_OP_WRITE_SAME))
1125 		return q->limits.max_write_same_sectors;
1126 
1127 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
1128 		return q->limits.max_write_zeroes_sectors;
1129 
1130 	return q->limits.max_sectors;
1131 }
1132 
1133 /*
1134  * Return maximum size of a request at given offset. Only valid for
1135  * file system requests.
1136  */
1137 static inline unsigned int blk_max_size_offset(struct request_queue *q,
1138 					       sector_t offset)
1139 {
1140 	if (!q->limits.chunk_sectors)
1141 		return q->limits.max_sectors;
1142 
1143 	return min(q->limits.max_sectors, (unsigned int)(q->limits.chunk_sectors -
1144 			(offset & (q->limits.chunk_sectors - 1))));
1145 }
1146 
1147 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
1148 						  sector_t offset)
1149 {
1150 	struct request_queue *q = rq->q;
1151 
1152 	if (blk_rq_is_passthrough(rq))
1153 		return q->limits.max_hw_sectors;
1154 
1155 	if (!q->limits.chunk_sectors ||
1156 	    req_op(rq) == REQ_OP_DISCARD ||
1157 	    req_op(rq) == REQ_OP_SECURE_ERASE)
1158 		return blk_queue_get_max_sectors(q, req_op(rq));
1159 
1160 	return min(blk_max_size_offset(q, offset),
1161 			blk_queue_get_max_sectors(q, req_op(rq)));
1162 }
1163 
1164 static inline unsigned int blk_rq_count_bios(struct request *rq)
1165 {
1166 	unsigned int nr_bios = 0;
1167 	struct bio *bio;
1168 
1169 	__rq_for_each_bio(bio, rq)
1170 		nr_bios++;
1171 
1172 	return nr_bios;
1173 }
1174 
1175 /*
1176  * Request issue related functions.
1177  */
1178 extern struct request *blk_peek_request(struct request_queue *q);
1179 extern void blk_start_request(struct request *rq);
1180 extern struct request *blk_fetch_request(struct request_queue *q);
1181 
1182 void blk_steal_bios(struct bio_list *list, struct request *rq);
1183 
1184 /*
1185  * Request completion related functions.
1186  *
1187  * blk_update_request() completes given number of bytes and updates
1188  * the request without completing it.
1189  *
1190  * blk_end_request() and friends.  __blk_end_request() must be called
1191  * with the request queue spinlock acquired.
1192  *
1193  * Several drivers define their own end_request and call
1194  * blk_end_request() for parts of the original function.
1195  * This prevents code duplication in drivers.
1196  */
1197 extern bool blk_update_request(struct request *rq, blk_status_t error,
1198 			       unsigned int nr_bytes);
1199 extern void blk_finish_request(struct request *rq, blk_status_t error);
1200 extern bool blk_end_request(struct request *rq, blk_status_t error,
1201 			    unsigned int nr_bytes);
1202 extern void blk_end_request_all(struct request *rq, blk_status_t error);
1203 extern bool __blk_end_request(struct request *rq, blk_status_t error,
1204 			      unsigned int nr_bytes);
1205 extern void __blk_end_request_all(struct request *rq, blk_status_t error);
1206 extern bool __blk_end_request_cur(struct request *rq, blk_status_t error);
1207 
1208 extern void blk_complete_request(struct request *);
1209 extern void __blk_complete_request(struct request *);
1210 extern void blk_abort_request(struct request *);
1211 extern void blk_unprep_request(struct request *);
1212 
1213 /*
1214  * Access functions for manipulating queue properties
1215  */
1216 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
1217 					spinlock_t *lock, int node_id);
1218 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
1219 extern int blk_init_allocated_queue(struct request_queue *);
1220 extern void blk_cleanup_queue(struct request_queue *);
1221 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1222 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1223 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1224 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1225 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1226 extern void blk_queue_max_discard_segments(struct request_queue *,
1227 		unsigned short);
1228 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1229 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1230 		unsigned int max_discard_sectors);
1231 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1232 		unsigned int max_write_same_sectors);
1233 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1234 		unsigned int max_write_same_sectors);
1235 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
1236 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1237 extern void blk_queue_alignment_offset(struct request_queue *q,
1238 				       unsigned int alignment);
1239 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1240 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1241 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1242 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1243 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1244 extern void blk_set_default_limits(struct queue_limits *lim);
1245 extern void blk_set_stacking_limits(struct queue_limits *lim);
1246 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1247 			    sector_t offset);
1248 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1249 			    sector_t offset);
1250 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1251 			      sector_t offset);
1252 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1253 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1254 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1255 extern int blk_queue_dma_drain(struct request_queue *q,
1256 			       dma_drain_needed_fn *dma_drain_needed,
1257 			       void *buf, unsigned int size);
1258 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1259 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1260 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1261 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1262 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
1263 extern void blk_queue_dma_alignment(struct request_queue *, int);
1264 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1265 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1266 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1267 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1268 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1269 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1270 
1271 /*
1272  * Number of physical segments as sent to the device.
1273  *
1274  * Normally this is the number of discontiguous data segments sent by the
1275  * submitter.  But for data-less command like discard we might have no
1276  * actual data segments submitted, but the driver might have to add it's
1277  * own special payload.  In that case we still return 1 here so that this
1278  * special payload will be mapped.
1279  */
1280 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1281 {
1282 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1283 		return 1;
1284 	return rq->nr_phys_segments;
1285 }
1286 
1287 /*
1288  * Number of discard segments (or ranges) the driver needs to fill in.
1289  * Each discard bio merged into a request is counted as one segment.
1290  */
1291 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1292 {
1293 	return max_t(unsigned short, rq->nr_phys_segments, 1);
1294 }
1295 
1296 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1297 extern void blk_dump_rq_flags(struct request *, char *);
1298 extern long nr_blockdev_pages(void);
1299 
1300 bool __must_check blk_get_queue(struct request_queue *);
1301 struct request_queue *blk_alloc_queue(gfp_t);
1302 struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
1303 					   spinlock_t *lock);
1304 extern void blk_put_queue(struct request_queue *);
1305 extern void blk_set_queue_dying(struct request_queue *);
1306 
1307 /*
1308  * blk_plug permits building a queue of related requests by holding the I/O
1309  * fragments for a short period. This allows merging of sequential requests
1310  * into single larger request. As the requests are moved from a per-task list to
1311  * the device's request_queue in a batch, this results in improved scalability
1312  * as the lock contention for request_queue lock is reduced.
1313  *
1314  * It is ok not to disable preemption when adding the request to the plug list
1315  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1316  * the plug list when the task sleeps by itself. For details, please see
1317  * schedule() where blk_schedule_flush_plug() is called.
1318  */
1319 struct blk_plug {
1320 	struct list_head list; /* requests */
1321 	struct list_head mq_list; /* blk-mq requests */
1322 	struct list_head cb_list; /* md requires an unplug callback */
1323 };
1324 #define BLK_MAX_REQUEST_COUNT 16
1325 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1326 
1327 struct blk_plug_cb;
1328 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1329 struct blk_plug_cb {
1330 	struct list_head list;
1331 	blk_plug_cb_fn callback;
1332 	void *data;
1333 };
1334 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1335 					     void *data, int size);
1336 extern void blk_start_plug(struct blk_plug *);
1337 extern void blk_finish_plug(struct blk_plug *);
1338 extern void blk_flush_plug_list(struct blk_plug *, bool);
1339 
1340 static inline void blk_flush_plug(struct task_struct *tsk)
1341 {
1342 	struct blk_plug *plug = tsk->plug;
1343 
1344 	if (plug)
1345 		blk_flush_plug_list(plug, false);
1346 }
1347 
1348 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1349 {
1350 	struct blk_plug *plug = tsk->plug;
1351 
1352 	if (plug)
1353 		blk_flush_plug_list(plug, true);
1354 }
1355 
1356 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1357 {
1358 	struct blk_plug *plug = tsk->plug;
1359 
1360 	return plug &&
1361 		(!list_empty(&plug->list) ||
1362 		 !list_empty(&plug->mq_list) ||
1363 		 !list_empty(&plug->cb_list));
1364 }
1365 
1366 /*
1367  * tag stuff
1368  */
1369 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1370 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1371 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1372 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
1373 extern void blk_queue_free_tags(struct request_queue *);
1374 extern int blk_queue_resize_tags(struct request_queue *, int);
1375 extern struct blk_queue_tag *blk_init_tags(int, int);
1376 extern void blk_free_tags(struct blk_queue_tag *);
1377 
1378 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1379 						int tag)
1380 {
1381 	if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1382 		return NULL;
1383 	return bqt->tag_index[tag];
1384 }
1385 
1386 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1387 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1388 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1389 
1390 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
1391 
1392 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1393 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1394 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1395 		sector_t nr_sects, gfp_t gfp_mask, int flags,
1396 		struct bio **biop);
1397 
1398 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
1399 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
1400 
1401 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1402 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1403 		unsigned flags);
1404 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1405 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1406 
1407 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1408 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1409 {
1410 	return blkdev_issue_discard(sb->s_bdev,
1411 				    block << (sb->s_blocksize_bits -
1412 					      SECTOR_SHIFT),
1413 				    nr_blocks << (sb->s_blocksize_bits -
1414 						  SECTOR_SHIFT),
1415 				    gfp_mask, flags);
1416 }
1417 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1418 		sector_t nr_blocks, gfp_t gfp_mask)
1419 {
1420 	return blkdev_issue_zeroout(sb->s_bdev,
1421 				    block << (sb->s_blocksize_bits -
1422 					      SECTOR_SHIFT),
1423 				    nr_blocks << (sb->s_blocksize_bits -
1424 						  SECTOR_SHIFT),
1425 				    gfp_mask, 0);
1426 }
1427 
1428 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1429 
1430 enum blk_default_limits {
1431 	BLK_MAX_SEGMENTS	= 128,
1432 	BLK_SAFE_MAX_SECTORS	= 255,
1433 	BLK_DEF_MAX_SECTORS	= 2560,
1434 	BLK_MAX_SEGMENT_SIZE	= 65536,
1435 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
1436 };
1437 
1438 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1439 {
1440 	return q->limits.seg_boundary_mask;
1441 }
1442 
1443 static inline unsigned long queue_virt_boundary(struct request_queue *q)
1444 {
1445 	return q->limits.virt_boundary_mask;
1446 }
1447 
1448 static inline unsigned int queue_max_sectors(struct request_queue *q)
1449 {
1450 	return q->limits.max_sectors;
1451 }
1452 
1453 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1454 {
1455 	return q->limits.max_hw_sectors;
1456 }
1457 
1458 static inline unsigned short queue_max_segments(struct request_queue *q)
1459 {
1460 	return q->limits.max_segments;
1461 }
1462 
1463 static inline unsigned short queue_max_discard_segments(struct request_queue *q)
1464 {
1465 	return q->limits.max_discard_segments;
1466 }
1467 
1468 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1469 {
1470 	return q->limits.max_segment_size;
1471 }
1472 
1473 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1474 {
1475 	int retval = 512;
1476 
1477 	if (q && q->limits.logical_block_size)
1478 		retval = q->limits.logical_block_size;
1479 
1480 	return retval;
1481 }
1482 
1483 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1484 {
1485 	return queue_logical_block_size(bdev_get_queue(bdev));
1486 }
1487 
1488 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1489 {
1490 	return q->limits.physical_block_size;
1491 }
1492 
1493 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1494 {
1495 	return queue_physical_block_size(bdev_get_queue(bdev));
1496 }
1497 
1498 static inline unsigned int queue_io_min(struct request_queue *q)
1499 {
1500 	return q->limits.io_min;
1501 }
1502 
1503 static inline int bdev_io_min(struct block_device *bdev)
1504 {
1505 	return queue_io_min(bdev_get_queue(bdev));
1506 }
1507 
1508 static inline unsigned int queue_io_opt(struct request_queue *q)
1509 {
1510 	return q->limits.io_opt;
1511 }
1512 
1513 static inline int bdev_io_opt(struct block_device *bdev)
1514 {
1515 	return queue_io_opt(bdev_get_queue(bdev));
1516 }
1517 
1518 static inline int queue_alignment_offset(struct request_queue *q)
1519 {
1520 	if (q->limits.misaligned)
1521 		return -1;
1522 
1523 	return q->limits.alignment_offset;
1524 }
1525 
1526 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1527 {
1528 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1529 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1530 		<< SECTOR_SHIFT;
1531 
1532 	return (granularity + lim->alignment_offset - alignment) % granularity;
1533 }
1534 
1535 static inline int bdev_alignment_offset(struct block_device *bdev)
1536 {
1537 	struct request_queue *q = bdev_get_queue(bdev);
1538 
1539 	if (q->limits.misaligned)
1540 		return -1;
1541 
1542 	if (bdev != bdev->bd_contains)
1543 		return bdev->bd_part->alignment_offset;
1544 
1545 	return q->limits.alignment_offset;
1546 }
1547 
1548 static inline int queue_discard_alignment(struct request_queue *q)
1549 {
1550 	if (q->limits.discard_misaligned)
1551 		return -1;
1552 
1553 	return q->limits.discard_alignment;
1554 }
1555 
1556 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1557 {
1558 	unsigned int alignment, granularity, offset;
1559 
1560 	if (!lim->max_discard_sectors)
1561 		return 0;
1562 
1563 	/* Why are these in bytes, not sectors? */
1564 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
1565 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
1566 	if (!granularity)
1567 		return 0;
1568 
1569 	/* Offset of the partition start in 'granularity' sectors */
1570 	offset = sector_div(sector, granularity);
1571 
1572 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
1573 	offset = (granularity + alignment - offset) % granularity;
1574 
1575 	/* Turn it back into bytes, gaah */
1576 	return offset << SECTOR_SHIFT;
1577 }
1578 
1579 static inline int bdev_discard_alignment(struct block_device *bdev)
1580 {
1581 	struct request_queue *q = bdev_get_queue(bdev);
1582 
1583 	if (bdev != bdev->bd_contains)
1584 		return bdev->bd_part->discard_alignment;
1585 
1586 	return q->limits.discard_alignment;
1587 }
1588 
1589 static inline unsigned int bdev_write_same(struct block_device *bdev)
1590 {
1591 	struct request_queue *q = bdev_get_queue(bdev);
1592 
1593 	if (q)
1594 		return q->limits.max_write_same_sectors;
1595 
1596 	return 0;
1597 }
1598 
1599 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1600 {
1601 	struct request_queue *q = bdev_get_queue(bdev);
1602 
1603 	if (q)
1604 		return q->limits.max_write_zeroes_sectors;
1605 
1606 	return 0;
1607 }
1608 
1609 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1610 {
1611 	struct request_queue *q = bdev_get_queue(bdev);
1612 
1613 	if (q)
1614 		return blk_queue_zoned_model(q);
1615 
1616 	return BLK_ZONED_NONE;
1617 }
1618 
1619 static inline bool bdev_is_zoned(struct block_device *bdev)
1620 {
1621 	struct request_queue *q = bdev_get_queue(bdev);
1622 
1623 	if (q)
1624 		return blk_queue_is_zoned(q);
1625 
1626 	return false;
1627 }
1628 
1629 static inline unsigned int bdev_zone_sectors(struct block_device *bdev)
1630 {
1631 	struct request_queue *q = bdev_get_queue(bdev);
1632 
1633 	if (q)
1634 		return blk_queue_zone_sectors(q);
1635 	return 0;
1636 }
1637 
1638 static inline int queue_dma_alignment(struct request_queue *q)
1639 {
1640 	return q ? q->dma_alignment : 511;
1641 }
1642 
1643 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1644 				 unsigned int len)
1645 {
1646 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1647 	return !(addr & alignment) && !(len & alignment);
1648 }
1649 
1650 /* assumes size > 256 */
1651 static inline unsigned int blksize_bits(unsigned int size)
1652 {
1653 	unsigned int bits = 8;
1654 	do {
1655 		bits++;
1656 		size >>= 1;
1657 	} while (size > 256);
1658 	return bits;
1659 }
1660 
1661 static inline unsigned int block_size(struct block_device *bdev)
1662 {
1663 	return bdev->bd_block_size;
1664 }
1665 
1666 static inline bool queue_flush_queueable(struct request_queue *q)
1667 {
1668 	return !test_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags);
1669 }
1670 
1671 typedef struct {struct page *v;} Sector;
1672 
1673 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1674 
1675 static inline void put_dev_sector(Sector p)
1676 {
1677 	put_page(p.v);
1678 }
1679 
1680 int kblockd_schedule_work(struct work_struct *work);
1681 int kblockd_schedule_work_on(int cpu, struct work_struct *work);
1682 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1683 
1684 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1685 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1686 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1687 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1688 
1689 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1690 
1691 enum blk_integrity_flags {
1692 	BLK_INTEGRITY_VERIFY		= 1 << 0,
1693 	BLK_INTEGRITY_GENERATE		= 1 << 1,
1694 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
1695 	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
1696 };
1697 
1698 struct blk_integrity_iter {
1699 	void			*prot_buf;
1700 	void			*data_buf;
1701 	sector_t		seed;
1702 	unsigned int		data_size;
1703 	unsigned short		interval;
1704 	const char		*disk_name;
1705 };
1706 
1707 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1708 
1709 struct blk_integrity_profile {
1710 	integrity_processing_fn		*generate_fn;
1711 	integrity_processing_fn		*verify_fn;
1712 	const char			*name;
1713 };
1714 
1715 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1716 extern void blk_integrity_unregister(struct gendisk *);
1717 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1718 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1719 				   struct scatterlist *);
1720 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1721 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1722 				   struct request *);
1723 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1724 				    struct bio *);
1725 
1726 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1727 {
1728 	struct blk_integrity *bi = &disk->queue->integrity;
1729 
1730 	if (!bi->profile)
1731 		return NULL;
1732 
1733 	return bi;
1734 }
1735 
1736 static inline
1737 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1738 {
1739 	return blk_get_integrity(bdev->bd_disk);
1740 }
1741 
1742 static inline bool blk_integrity_rq(struct request *rq)
1743 {
1744 	return rq->cmd_flags & REQ_INTEGRITY;
1745 }
1746 
1747 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1748 						    unsigned int segs)
1749 {
1750 	q->limits.max_integrity_segments = segs;
1751 }
1752 
1753 static inline unsigned short
1754 queue_max_integrity_segments(struct request_queue *q)
1755 {
1756 	return q->limits.max_integrity_segments;
1757 }
1758 
1759 /**
1760  * bio_integrity_intervals - Return number of integrity intervals for a bio
1761  * @bi:		blk_integrity profile for device
1762  * @sectors:	Size of the bio in 512-byte sectors
1763  *
1764  * Description: The block layer calculates everything in 512 byte
1765  * sectors but integrity metadata is done in terms of the data integrity
1766  * interval size of the storage device.  Convert the block layer sectors
1767  * to the appropriate number of integrity intervals.
1768  */
1769 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1770 						   unsigned int sectors)
1771 {
1772 	return sectors >> (bi->interval_exp - 9);
1773 }
1774 
1775 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1776 					       unsigned int sectors)
1777 {
1778 	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
1779 }
1780 
1781 #else /* CONFIG_BLK_DEV_INTEGRITY */
1782 
1783 struct bio;
1784 struct block_device;
1785 struct gendisk;
1786 struct blk_integrity;
1787 
1788 static inline int blk_integrity_rq(struct request *rq)
1789 {
1790 	return 0;
1791 }
1792 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1793 					    struct bio *b)
1794 {
1795 	return 0;
1796 }
1797 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1798 					  struct bio *b,
1799 					  struct scatterlist *s)
1800 {
1801 	return 0;
1802 }
1803 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1804 {
1805 	return NULL;
1806 }
1807 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1808 {
1809 	return NULL;
1810 }
1811 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1812 {
1813 	return 0;
1814 }
1815 static inline void blk_integrity_register(struct gendisk *d,
1816 					 struct blk_integrity *b)
1817 {
1818 }
1819 static inline void blk_integrity_unregister(struct gendisk *d)
1820 {
1821 }
1822 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1823 						    unsigned int segs)
1824 {
1825 }
1826 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1827 {
1828 	return 0;
1829 }
1830 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1831 					  struct request *r1,
1832 					  struct request *r2)
1833 {
1834 	return true;
1835 }
1836 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1837 					   struct request *r,
1838 					   struct bio *b)
1839 {
1840 	return true;
1841 }
1842 
1843 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1844 						   unsigned int sectors)
1845 {
1846 	return 0;
1847 }
1848 
1849 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1850 					       unsigned int sectors)
1851 {
1852 	return 0;
1853 }
1854 
1855 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1856 
1857 struct block_device_operations {
1858 	int (*open) (struct block_device *, fmode_t);
1859 	void (*release) (struct gendisk *, fmode_t);
1860 	int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
1861 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1862 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1863 	unsigned int (*check_events) (struct gendisk *disk,
1864 				      unsigned int clearing);
1865 	/* ->media_changed() is DEPRECATED, use ->check_events() instead */
1866 	int (*media_changed) (struct gendisk *);
1867 	void (*unlock_native_capacity) (struct gendisk *);
1868 	int (*revalidate_disk) (struct gendisk *);
1869 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1870 	/* this callback is with swap_lock and sometimes page table lock held */
1871 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1872 	int (*report_zones)(struct gendisk *, sector_t sector,
1873 			    struct blk_zone *zones, unsigned int *nr_zones,
1874 			    gfp_t gfp_mask);
1875 	struct module *owner;
1876 	const struct pr_ops *pr_ops;
1877 };
1878 
1879 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1880 				 unsigned long);
1881 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1882 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1883 						struct writeback_control *);
1884 
1885 #ifdef CONFIG_BLK_DEV_ZONED
1886 bool blk_req_needs_zone_write_lock(struct request *rq);
1887 void __blk_req_zone_write_lock(struct request *rq);
1888 void __blk_req_zone_write_unlock(struct request *rq);
1889 
1890 static inline void blk_req_zone_write_lock(struct request *rq)
1891 {
1892 	if (blk_req_needs_zone_write_lock(rq))
1893 		__blk_req_zone_write_lock(rq);
1894 }
1895 
1896 static inline void blk_req_zone_write_unlock(struct request *rq)
1897 {
1898 	if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
1899 		__blk_req_zone_write_unlock(rq);
1900 }
1901 
1902 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1903 {
1904 	return rq->q->seq_zones_wlock &&
1905 		test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
1906 }
1907 
1908 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1909 {
1910 	if (!blk_req_needs_zone_write_lock(rq))
1911 		return true;
1912 	return !blk_req_zone_is_write_locked(rq);
1913 }
1914 #else
1915 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
1916 {
1917 	return false;
1918 }
1919 
1920 static inline void blk_req_zone_write_lock(struct request *rq)
1921 {
1922 }
1923 
1924 static inline void blk_req_zone_write_unlock(struct request *rq)
1925 {
1926 }
1927 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1928 {
1929 	return false;
1930 }
1931 
1932 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1933 {
1934 	return true;
1935 }
1936 #endif /* CONFIG_BLK_DEV_ZONED */
1937 
1938 #else /* CONFIG_BLOCK */
1939 
1940 struct block_device;
1941 
1942 /*
1943  * stubs for when the block layer is configured out
1944  */
1945 #define buffer_heads_over_limit 0
1946 
1947 static inline long nr_blockdev_pages(void)
1948 {
1949 	return 0;
1950 }
1951 
1952 struct blk_plug {
1953 };
1954 
1955 static inline void blk_start_plug(struct blk_plug *plug)
1956 {
1957 }
1958 
1959 static inline void blk_finish_plug(struct blk_plug *plug)
1960 {
1961 }
1962 
1963 static inline void blk_flush_plug(struct task_struct *task)
1964 {
1965 }
1966 
1967 static inline void blk_schedule_flush_plug(struct task_struct *task)
1968 {
1969 }
1970 
1971 
1972 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1973 {
1974 	return false;
1975 }
1976 
1977 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1978 				     sector_t *error_sector)
1979 {
1980 	return 0;
1981 }
1982 
1983 #endif /* CONFIG_BLOCK */
1984 
1985 #endif
1986