xref: /linux-6.15/include/linux/blkdev.h (revision ef6c8da7)
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/wait.h>
15 #include <linux/mempool.h>
16 #include <linux/pfn.h>
17 #include <linux/bio.h>
18 #include <linux/stringify.h>
19 #include <linux/gfp.h>
20 #include <linux/bsg.h>
21 #include <linux/smp.h>
22 #include <linux/rcupdate.h>
23 #include <linux/percpu-refcount.h>
24 #include <linux/scatterlist.h>
25 #include <linux/blkzoned.h>
26 #include <linux/pm.h>
27 #include <linux/sbitmap.h>
28 
29 struct module;
30 struct scsi_ioctl_command;
31 
32 struct request_queue;
33 struct elevator_queue;
34 struct blk_trace;
35 struct request;
36 struct sg_io_hdr;
37 struct bsg_job;
38 struct blkcg_gq;
39 struct blk_flush_queue;
40 struct pr_ops;
41 struct rq_qos;
42 struct blk_queue_stats;
43 struct blk_stat_callback;
44 struct blk_keyslot_manager;
45 
46 #define BLKDEV_MIN_RQ	4
47 #define BLKDEV_MAX_RQ	128	/* Default maximum */
48 
49 /* Must be consistent with blk_mq_poll_stats_bkt() */
50 #define BLK_MQ_POLL_STATS_BKTS 16
51 
52 /* Doing classic polling */
53 #define BLK_MQ_POLL_CLASSIC -1
54 
55 /*
56  * Maximum number of blkcg policies allowed to be registered concurrently.
57  * Defined here to simplify include dependency.
58  */
59 #define BLKCG_MAX_POLS		6
60 
61 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
62 
63 /*
64  * request flags */
65 typedef __u32 __bitwise req_flags_t;
66 
67 /* drive already may have started this one */
68 #define RQF_STARTED		((__force req_flags_t)(1 << 1))
69 /* may not be passed by ioscheduler */
70 #define RQF_SOFTBARRIER		((__force req_flags_t)(1 << 3))
71 /* request for flush sequence */
72 #define RQF_FLUSH_SEQ		((__force req_flags_t)(1 << 4))
73 /* merge of different types, fail separately */
74 #define RQF_MIXED_MERGE		((__force req_flags_t)(1 << 5))
75 /* track inflight for MQ */
76 #define RQF_MQ_INFLIGHT		((__force req_flags_t)(1 << 6))
77 /* don't call prep for this one */
78 #define RQF_DONTPREP		((__force req_flags_t)(1 << 7))
79 /* vaguely specified driver internal error.  Ignored by the block layer */
80 #define RQF_FAILED		((__force req_flags_t)(1 << 10))
81 /* don't warn about errors */
82 #define RQF_QUIET		((__force req_flags_t)(1 << 11))
83 /* elevator private data attached */
84 #define RQF_ELVPRIV		((__force req_flags_t)(1 << 12))
85 /* account into disk and partition IO statistics */
86 #define RQF_IO_STAT		((__force req_flags_t)(1 << 13))
87 /* runtime pm request */
88 #define RQF_PM			((__force req_flags_t)(1 << 15))
89 /* on IO scheduler merge hash */
90 #define RQF_HASHED		((__force req_flags_t)(1 << 16))
91 /* track IO completion time */
92 #define RQF_STATS		((__force req_flags_t)(1 << 17))
93 /* Look at ->special_vec for the actual data payload instead of the
94    bio chain. */
95 #define RQF_SPECIAL_PAYLOAD	((__force req_flags_t)(1 << 18))
96 /* The per-zone write lock is held for this request */
97 #define RQF_ZONE_WRITE_LOCKED	((__force req_flags_t)(1 << 19))
98 /* already slept for hybrid poll */
99 #define RQF_MQ_POLL_SLEPT	((__force req_flags_t)(1 << 20))
100 /* ->timeout has been called, don't expire again */
101 #define RQF_TIMED_OUT		((__force req_flags_t)(1 << 21))
102 
103 /* flags that prevent us from merging requests: */
104 #define RQF_NOMERGE_FLAGS \
105 	(RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
106 
107 /*
108  * Request state for blk-mq.
109  */
110 enum mq_rq_state {
111 	MQ_RQ_IDLE		= 0,
112 	MQ_RQ_IN_FLIGHT		= 1,
113 	MQ_RQ_COMPLETE		= 2,
114 };
115 
116 /*
117  * Try to put the fields that are referenced together in the same cacheline.
118  *
119  * If you modify this structure, make sure to update blk_rq_init() and
120  * especially blk_mq_rq_ctx_init() to take care of the added fields.
121  */
122 struct request {
123 	struct request_queue *q;
124 	struct blk_mq_ctx *mq_ctx;
125 	struct blk_mq_hw_ctx *mq_hctx;
126 
127 	unsigned int cmd_flags;		/* op and common flags */
128 	req_flags_t rq_flags;
129 
130 	int tag;
131 	int internal_tag;
132 
133 	/* the following two fields are internal, NEVER access directly */
134 	unsigned int __data_len;	/* total data len */
135 	sector_t __sector;		/* sector cursor */
136 
137 	struct bio *bio;
138 	struct bio *biotail;
139 
140 	struct list_head queuelist;
141 
142 	/*
143 	 * The hash is used inside the scheduler, and killed once the
144 	 * request reaches the dispatch list. The ipi_list is only used
145 	 * to queue the request for softirq completion, which is long
146 	 * after the request has been unhashed (and even removed from
147 	 * the dispatch list).
148 	 */
149 	union {
150 		struct hlist_node hash;	/* merge hash */
151 		struct llist_node ipi_list;
152 	};
153 
154 	/*
155 	 * The rb_node is only used inside the io scheduler, requests
156 	 * are pruned when moved to the dispatch queue. So let the
157 	 * completion_data share space with the rb_node.
158 	 */
159 	union {
160 		struct rb_node rb_node;	/* sort/lookup */
161 		struct bio_vec special_vec;
162 		void *completion_data;
163 		int error_count; /* for legacy drivers, don't use */
164 	};
165 
166 	/*
167 	 * Three pointers are available for the IO schedulers, if they need
168 	 * more they have to dynamically allocate it.  Flush requests are
169 	 * never put on the IO scheduler. So let the flush fields share
170 	 * space with the elevator data.
171 	 */
172 	union {
173 		struct {
174 			struct io_cq		*icq;
175 			void			*priv[2];
176 		} elv;
177 
178 		struct {
179 			unsigned int		seq;
180 			struct list_head	list;
181 			rq_end_io_fn		*saved_end_io;
182 		} flush;
183 	};
184 
185 	struct gendisk *rq_disk;
186 	struct block_device *part;
187 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
188 	/* Time that the first bio started allocating this request. */
189 	u64 alloc_time_ns;
190 #endif
191 	/* Time that this request was allocated for this IO. */
192 	u64 start_time_ns;
193 	/* Time that I/O was submitted to the device. */
194 	u64 io_start_time_ns;
195 
196 #ifdef CONFIG_BLK_WBT
197 	unsigned short wbt_flags;
198 #endif
199 	/*
200 	 * rq sectors used for blk stats. It has the same value
201 	 * with blk_rq_sectors(rq), except that it never be zeroed
202 	 * by completion.
203 	 */
204 	unsigned short stats_sectors;
205 
206 	/*
207 	 * Number of scatter-gather DMA addr+len pairs after
208 	 * physical address coalescing is performed.
209 	 */
210 	unsigned short nr_phys_segments;
211 
212 #if defined(CONFIG_BLK_DEV_INTEGRITY)
213 	unsigned short nr_integrity_segments;
214 #endif
215 
216 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
217 	struct bio_crypt_ctx *crypt_ctx;
218 	struct blk_ksm_keyslot *crypt_keyslot;
219 #endif
220 
221 	unsigned short write_hint;
222 	unsigned short ioprio;
223 
224 	enum mq_rq_state state;
225 	refcount_t ref;
226 
227 	unsigned int timeout;
228 	unsigned long deadline;
229 
230 	union {
231 		struct __call_single_data csd;
232 		u64 fifo_time;
233 	};
234 
235 	/*
236 	 * completion callback.
237 	 */
238 	rq_end_io_fn *end_io;
239 	void *end_io_data;
240 };
241 
242 static inline bool blk_op_is_passthrough(unsigned int op)
243 {
244 	op &= REQ_OP_MASK;
245 	return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
246 }
247 
248 static inline bool blk_rq_is_passthrough(struct request *rq)
249 {
250 	return blk_op_is_passthrough(req_op(rq));
251 }
252 
253 static inline unsigned short req_get_ioprio(struct request *req)
254 {
255 	return req->ioprio;
256 }
257 
258 #include <linux/elevator.h>
259 
260 struct blk_queue_ctx;
261 
262 struct bio_vec;
263 
264 enum blk_eh_timer_return {
265 	BLK_EH_DONE,		/* drivers has completed the command */
266 	BLK_EH_RESET_TIMER,	/* reset timer and try again */
267 };
268 
269 enum blk_queue_state {
270 	Queue_down,
271 	Queue_up,
272 };
273 
274 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
275 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
276 
277 #define BLK_SCSI_MAX_CMDS	(256)
278 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
279 
280 /*
281  * Zoned block device models (zoned limit).
282  *
283  * Note: This needs to be ordered from the least to the most severe
284  * restrictions for the inheritance in blk_stack_limits() to work.
285  */
286 enum blk_zoned_model {
287 	BLK_ZONED_NONE = 0,	/* Regular block device */
288 	BLK_ZONED_HA,		/* Host-aware zoned block device */
289 	BLK_ZONED_HM,		/* Host-managed zoned block device */
290 };
291 
292 /*
293  * BLK_BOUNCE_NONE:	never bounce (default)
294  * BLK_BOUNCE_HIGH:	bounce all highmem pages
295  */
296 enum blk_bounce {
297 	BLK_BOUNCE_NONE,
298 	BLK_BOUNCE_HIGH,
299 };
300 
301 struct queue_limits {
302 	enum blk_bounce		bounce;
303 	unsigned long		seg_boundary_mask;
304 	unsigned long		virt_boundary_mask;
305 
306 	unsigned int		max_hw_sectors;
307 	unsigned int		max_dev_sectors;
308 	unsigned int		chunk_sectors;
309 	unsigned int		max_sectors;
310 	unsigned int		max_segment_size;
311 	unsigned int		physical_block_size;
312 	unsigned int		logical_block_size;
313 	unsigned int		alignment_offset;
314 	unsigned int		io_min;
315 	unsigned int		io_opt;
316 	unsigned int		max_discard_sectors;
317 	unsigned int		max_hw_discard_sectors;
318 	unsigned int		max_write_same_sectors;
319 	unsigned int		max_write_zeroes_sectors;
320 	unsigned int		max_zone_append_sectors;
321 	unsigned int		discard_granularity;
322 	unsigned int		discard_alignment;
323 	unsigned int		zone_write_granularity;
324 
325 	unsigned short		max_segments;
326 	unsigned short		max_integrity_segments;
327 	unsigned short		max_discard_segments;
328 
329 	unsigned char		misaligned;
330 	unsigned char		discard_misaligned;
331 	unsigned char		raid_partial_stripes_expensive;
332 	enum blk_zoned_model	zoned;
333 };
334 
335 typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,
336 			       void *data);
337 
338 void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model);
339 
340 #ifdef CONFIG_BLK_DEV_ZONED
341 
342 #define BLK_ALL_ZONES  ((unsigned int)-1)
343 int blkdev_report_zones(struct block_device *bdev, sector_t sector,
344 			unsigned int nr_zones, report_zones_cb cb, void *data);
345 unsigned int blkdev_nr_zones(struct gendisk *disk);
346 extern int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
347 			    sector_t sectors, sector_t nr_sectors,
348 			    gfp_t gfp_mask);
349 int blk_revalidate_disk_zones(struct gendisk *disk,
350 			      void (*update_driver_data)(struct gendisk *disk));
351 
352 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
353 				     unsigned int cmd, unsigned long arg);
354 extern int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
355 				  unsigned int cmd, unsigned long arg);
356 
357 #else /* CONFIG_BLK_DEV_ZONED */
358 
359 static inline unsigned int blkdev_nr_zones(struct gendisk *disk)
360 {
361 	return 0;
362 }
363 
364 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
365 					    fmode_t mode, unsigned int cmd,
366 					    unsigned long arg)
367 {
368 	return -ENOTTY;
369 }
370 
371 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
372 					 fmode_t mode, unsigned int cmd,
373 					 unsigned long arg)
374 {
375 	return -ENOTTY;
376 }
377 
378 #endif /* CONFIG_BLK_DEV_ZONED */
379 
380 struct request_queue {
381 	struct request		*last_merge;
382 	struct elevator_queue	*elevator;
383 
384 	struct percpu_ref	q_usage_counter;
385 
386 	struct blk_queue_stats	*stats;
387 	struct rq_qos		*rq_qos;
388 
389 	const struct blk_mq_ops	*mq_ops;
390 
391 	/* sw queues */
392 	struct blk_mq_ctx __percpu	*queue_ctx;
393 
394 	unsigned int		queue_depth;
395 
396 	/* hw dispatch queues */
397 	struct blk_mq_hw_ctx	**queue_hw_ctx;
398 	unsigned int		nr_hw_queues;
399 
400 	/*
401 	 * The queue owner gets to use this for whatever they like.
402 	 * ll_rw_blk doesn't touch it.
403 	 */
404 	void			*queuedata;
405 
406 	/*
407 	 * various queue flags, see QUEUE_* below
408 	 */
409 	unsigned long		queue_flags;
410 	/*
411 	 * Number of contexts that have called blk_set_pm_only(). If this
412 	 * counter is above zero then only RQF_PM requests are processed.
413 	 */
414 	atomic_t		pm_only;
415 
416 	/*
417 	 * ida allocated id for this queue.  Used to index queues from
418 	 * ioctx.
419 	 */
420 	int			id;
421 
422 	spinlock_t		queue_lock;
423 
424 	struct gendisk		*disk;
425 
426 	/*
427 	 * queue kobject
428 	 */
429 	struct kobject kobj;
430 
431 	/*
432 	 * mq queue kobject
433 	 */
434 	struct kobject *mq_kobj;
435 
436 #ifdef  CONFIG_BLK_DEV_INTEGRITY
437 	struct blk_integrity integrity;
438 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
439 
440 #ifdef CONFIG_PM
441 	struct device		*dev;
442 	enum rpm_status		rpm_status;
443 #endif
444 
445 	/*
446 	 * queue settings
447 	 */
448 	unsigned long		nr_requests;	/* Max # of requests */
449 
450 	unsigned int		dma_pad_mask;
451 	unsigned int		dma_alignment;
452 
453 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
454 	/* Inline crypto capabilities */
455 	struct blk_keyslot_manager *ksm;
456 #endif
457 
458 	unsigned int		rq_timeout;
459 	int			poll_nsec;
460 
461 	struct blk_stat_callback	*poll_cb;
462 	struct blk_rq_stat	poll_stat[BLK_MQ_POLL_STATS_BKTS];
463 
464 	struct timer_list	timeout;
465 	struct work_struct	timeout_work;
466 
467 	atomic_t		nr_active_requests_shared_sbitmap;
468 
469 	struct sbitmap_queue	sched_bitmap_tags;
470 	struct sbitmap_queue	sched_breserved_tags;
471 
472 	struct list_head	icq_list;
473 #ifdef CONFIG_BLK_CGROUP
474 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
475 	struct blkcg_gq		*root_blkg;
476 	struct list_head	blkg_list;
477 #endif
478 
479 	struct queue_limits	limits;
480 
481 	unsigned int		required_elevator_features;
482 
483 #ifdef CONFIG_BLK_DEV_ZONED
484 	/*
485 	 * Zoned block device information for request dispatch control.
486 	 * nr_zones is the total number of zones of the device. This is always
487 	 * 0 for regular block devices. conv_zones_bitmap is a bitmap of nr_zones
488 	 * bits which indicates if a zone is conventional (bit set) or
489 	 * sequential (bit clear). seq_zones_wlock is a bitmap of nr_zones
490 	 * bits which indicates if a zone is write locked, that is, if a write
491 	 * request targeting the zone was dispatched. All three fields are
492 	 * initialized by the low level device driver (e.g. scsi/sd.c).
493 	 * Stacking drivers (device mappers) may or may not initialize
494 	 * these fields.
495 	 *
496 	 * Reads of this information must be protected with blk_queue_enter() /
497 	 * blk_queue_exit(). Modifying this information is only allowed while
498 	 * no requests are being processed. See also blk_mq_freeze_queue() and
499 	 * blk_mq_unfreeze_queue().
500 	 */
501 	unsigned int		nr_zones;
502 	unsigned long		*conv_zones_bitmap;
503 	unsigned long		*seq_zones_wlock;
504 	unsigned int		max_open_zones;
505 	unsigned int		max_active_zones;
506 #endif /* CONFIG_BLK_DEV_ZONED */
507 
508 	/*
509 	 * sg stuff
510 	 */
511 	unsigned int		sg_timeout;
512 	unsigned int		sg_reserved_size;
513 	int			node;
514 	struct mutex		debugfs_mutex;
515 #ifdef CONFIG_BLK_DEV_IO_TRACE
516 	struct blk_trace __rcu	*blk_trace;
517 #endif
518 	/*
519 	 * for flush operations
520 	 */
521 	struct blk_flush_queue	*fq;
522 
523 	struct list_head	requeue_list;
524 	spinlock_t		requeue_lock;
525 	struct delayed_work	requeue_work;
526 
527 	struct mutex		sysfs_lock;
528 	struct mutex		sysfs_dir_lock;
529 
530 	/*
531 	 * for reusing dead hctx instance in case of updating
532 	 * nr_hw_queues
533 	 */
534 	struct list_head	unused_hctx_list;
535 	spinlock_t		unused_hctx_lock;
536 
537 	int			mq_freeze_depth;
538 
539 #if defined(CONFIG_BLK_DEV_BSG)
540 	struct bsg_class_device bsg_dev;
541 #endif
542 
543 #ifdef CONFIG_BLK_DEV_THROTTLING
544 	/* Throttle data */
545 	struct throtl_data *td;
546 #endif
547 	struct rcu_head		rcu_head;
548 	wait_queue_head_t	mq_freeze_wq;
549 	/*
550 	 * Protect concurrent access to q_usage_counter by
551 	 * percpu_ref_kill() and percpu_ref_reinit().
552 	 */
553 	struct mutex		mq_freeze_lock;
554 
555 	struct blk_mq_tag_set	*tag_set;
556 	struct list_head	tag_set_list;
557 	struct bio_set		bio_split;
558 
559 	struct dentry		*debugfs_dir;
560 
561 #ifdef CONFIG_BLK_DEBUG_FS
562 	struct dentry		*sched_debugfs_dir;
563 	struct dentry		*rqos_debugfs_dir;
564 #endif
565 
566 	bool			mq_sysfs_init_done;
567 
568 	size_t			cmd_size;
569 
570 #define BLK_MAX_WRITE_HINTS	5
571 	u64			write_hints[BLK_MAX_WRITE_HINTS];
572 };
573 
574 /* Keep blk_queue_flag_name[] in sync with the definitions below */
575 #define QUEUE_FLAG_STOPPED	0	/* queue is stopped */
576 #define QUEUE_FLAG_DYING	1	/* queue being torn down */
577 #define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
578 #define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
579 #define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
580 #define QUEUE_FLAG_NONROT	6	/* non-rotational device (SSD) */
581 #define QUEUE_FLAG_VIRT		QUEUE_FLAG_NONROT /* paravirt device */
582 #define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
583 #define QUEUE_FLAG_DISCARD	8	/* supports DISCARD */
584 #define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
585 #define QUEUE_FLAG_ADD_RANDOM	10	/* Contributes to random pool */
586 #define QUEUE_FLAG_SECERASE	11	/* supports secure erase */
587 #define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
588 #define QUEUE_FLAG_DEAD		13	/* queue tear-down finished */
589 #define QUEUE_FLAG_INIT_DONE	14	/* queue is initialized */
590 #define QUEUE_FLAG_STABLE_WRITES 15	/* don't modify blks until WB is done */
591 #define QUEUE_FLAG_POLL		16	/* IO polling enabled if set */
592 #define QUEUE_FLAG_WC		17	/* Write back caching */
593 #define QUEUE_FLAG_FUA		18	/* device supports FUA writes */
594 #define QUEUE_FLAG_DAX		19	/* device supports DAX */
595 #define QUEUE_FLAG_STATS	20	/* track IO start and completion times */
596 #define QUEUE_FLAG_POLL_STATS	21	/* collecting stats for hybrid polling */
597 #define QUEUE_FLAG_REGISTERED	22	/* queue has been registered to a disk */
598 #define QUEUE_FLAG_SCSI_PASSTHROUGH 23	/* queue supports SCSI commands */
599 #define QUEUE_FLAG_QUIESCED	24	/* queue has been quiesced */
600 #define QUEUE_FLAG_PCI_P2PDMA	25	/* device supports PCI p2p requests */
601 #define QUEUE_FLAG_ZONE_RESETALL 26	/* supports Zone Reset All */
602 #define QUEUE_FLAG_RQ_ALLOC_TIME 27	/* record rq->alloc_time_ns */
603 #define QUEUE_FLAG_HCTX_ACTIVE	28	/* at least one blk-mq hctx is active */
604 #define QUEUE_FLAG_NOWAIT       29	/* device supports NOWAIT */
605 
606 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
607 				 (1 << QUEUE_FLAG_SAME_COMP) |		\
608 				 (1 << QUEUE_FLAG_NOWAIT))
609 
610 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
611 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
612 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
613 
614 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
615 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
616 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
617 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
618 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
619 #define blk_queue_noxmerges(q)	\
620 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
621 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
622 #define blk_queue_stable_writes(q) \
623 	test_bit(QUEUE_FLAG_STABLE_WRITES, &(q)->queue_flags)
624 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
625 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
626 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
627 #define blk_queue_zone_resetall(q)	\
628 	test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
629 #define blk_queue_secure_erase(q) \
630 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
631 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
632 #define blk_queue_scsi_passthrough(q)	\
633 	test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
634 #define blk_queue_pci_p2pdma(q)	\
635 	test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
636 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
637 #define blk_queue_rq_alloc_time(q)	\
638 	test_bit(QUEUE_FLAG_RQ_ALLOC_TIME, &(q)->queue_flags)
639 #else
640 #define blk_queue_rq_alloc_time(q)	false
641 #endif
642 
643 #define blk_noretry_request(rq) \
644 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
645 			     REQ_FAILFAST_DRIVER))
646 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
647 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
648 #define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
649 #define blk_queue_registered(q)	test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
650 #define blk_queue_nowait(q)	test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags)
651 
652 extern void blk_set_pm_only(struct request_queue *q);
653 extern void blk_clear_pm_only(struct request_queue *q);
654 
655 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
656 
657 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
658 
659 #define rq_dma_dir(rq) \
660 	(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
661 
662 #define dma_map_bvec(dev, bv, dir, attrs) \
663 	dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
664 	(dir), (attrs))
665 
666 static inline bool queue_is_mq(struct request_queue *q)
667 {
668 	return q->mq_ops;
669 }
670 
671 #ifdef CONFIG_PM
672 static inline enum rpm_status queue_rpm_status(struct request_queue *q)
673 {
674 	return q->rpm_status;
675 }
676 #else
677 static inline enum rpm_status queue_rpm_status(struct request_queue *q)
678 {
679 	return RPM_ACTIVE;
680 }
681 #endif
682 
683 static inline enum blk_zoned_model
684 blk_queue_zoned_model(struct request_queue *q)
685 {
686 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
687 		return q->limits.zoned;
688 	return BLK_ZONED_NONE;
689 }
690 
691 static inline bool blk_queue_is_zoned(struct request_queue *q)
692 {
693 	switch (blk_queue_zoned_model(q)) {
694 	case BLK_ZONED_HA:
695 	case BLK_ZONED_HM:
696 		return true;
697 	default:
698 		return false;
699 	}
700 }
701 
702 static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
703 {
704 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
705 }
706 
707 #ifdef CONFIG_BLK_DEV_ZONED
708 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
709 {
710 	return blk_queue_is_zoned(q) ? q->nr_zones : 0;
711 }
712 
713 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
714 					     sector_t sector)
715 {
716 	if (!blk_queue_is_zoned(q))
717 		return 0;
718 	return sector >> ilog2(q->limits.chunk_sectors);
719 }
720 
721 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
722 					 sector_t sector)
723 {
724 	if (!blk_queue_is_zoned(q))
725 		return false;
726 	if (!q->conv_zones_bitmap)
727 		return true;
728 	return !test_bit(blk_queue_zone_no(q, sector), q->conv_zones_bitmap);
729 }
730 
731 static inline void blk_queue_max_open_zones(struct request_queue *q,
732 		unsigned int max_open_zones)
733 {
734 	q->max_open_zones = max_open_zones;
735 }
736 
737 static inline unsigned int queue_max_open_zones(const struct request_queue *q)
738 {
739 	return q->max_open_zones;
740 }
741 
742 static inline void blk_queue_max_active_zones(struct request_queue *q,
743 		unsigned int max_active_zones)
744 {
745 	q->max_active_zones = max_active_zones;
746 }
747 
748 static inline unsigned int queue_max_active_zones(const struct request_queue *q)
749 {
750 	return q->max_active_zones;
751 }
752 #else /* CONFIG_BLK_DEV_ZONED */
753 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
754 {
755 	return 0;
756 }
757 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
758 					 sector_t sector)
759 {
760 	return false;
761 }
762 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
763 					     sector_t sector)
764 {
765 	return 0;
766 }
767 static inline unsigned int queue_max_open_zones(const struct request_queue *q)
768 {
769 	return 0;
770 }
771 static inline unsigned int queue_max_active_zones(const struct request_queue *q)
772 {
773 	return 0;
774 }
775 #endif /* CONFIG_BLK_DEV_ZONED */
776 
777 static inline bool rq_is_sync(struct request *rq)
778 {
779 	return op_is_sync(rq->cmd_flags);
780 }
781 
782 static inline bool rq_mergeable(struct request *rq)
783 {
784 	if (blk_rq_is_passthrough(rq))
785 		return false;
786 
787 	if (req_op(rq) == REQ_OP_FLUSH)
788 		return false;
789 
790 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
791 		return false;
792 
793 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
794 		return false;
795 
796 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
797 		return false;
798 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
799 		return false;
800 
801 	return true;
802 }
803 
804 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
805 {
806 	if (bio_page(a) == bio_page(b) &&
807 	    bio_offset(a) == bio_offset(b))
808 		return true;
809 
810 	return false;
811 }
812 
813 static inline unsigned int blk_queue_depth(struct request_queue *q)
814 {
815 	if (q->queue_depth)
816 		return q->queue_depth;
817 
818 	return q->nr_requests;
819 }
820 
821 /*
822  * default timeout for SG_IO if none specified
823  */
824 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
825 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
826 
827 struct rq_map_data {
828 	struct page **pages;
829 	int page_order;
830 	int nr_entries;
831 	unsigned long offset;
832 	int null_mapped;
833 	int from_user;
834 };
835 
836 struct req_iterator {
837 	struct bvec_iter iter;
838 	struct bio *bio;
839 };
840 
841 /* This should not be used directly - use rq_for_each_segment */
842 #define for_each_bio(_bio)		\
843 	for (; _bio; _bio = _bio->bi_next)
844 #define __rq_for_each_bio(_bio, rq)	\
845 	if ((rq->bio))			\
846 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
847 
848 #define rq_for_each_segment(bvl, _rq, _iter)			\
849 	__rq_for_each_bio(_iter.bio, _rq)			\
850 		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
851 
852 #define rq_for_each_bvec(bvl, _rq, _iter)			\
853 	__rq_for_each_bio(_iter.bio, _rq)			\
854 		bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
855 
856 #define rq_iter_last(bvec, _iter)				\
857 		(_iter.bio->bi_next == NULL &&			\
858 		 bio_iter_last(bvec, _iter.iter))
859 
860 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
861 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
862 #endif
863 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
864 extern void rq_flush_dcache_pages(struct request *rq);
865 #else
866 static inline void rq_flush_dcache_pages(struct request *rq)
867 {
868 }
869 #endif
870 
871 extern int blk_register_queue(struct gendisk *disk);
872 extern void blk_unregister_queue(struct gendisk *disk);
873 blk_qc_t submit_bio_noacct(struct bio *bio);
874 extern void blk_rq_init(struct request_queue *q, struct request *rq);
875 extern void blk_put_request(struct request *);
876 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
877 				       blk_mq_req_flags_t flags);
878 extern int blk_lld_busy(struct request_queue *q);
879 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
880 			     struct bio_set *bs, gfp_t gfp_mask,
881 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
882 			     void *data);
883 extern void blk_rq_unprep_clone(struct request *rq);
884 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
885 				     struct request *rq);
886 int blk_rq_append_bio(struct request *rq, struct bio *bio);
887 extern void blk_queue_split(struct bio **);
888 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
889 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
890 			      unsigned int, void __user *);
891 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
892 			  unsigned int, void __user *);
893 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
894 			 struct scsi_ioctl_command __user *);
895 extern int get_sg_io_hdr(struct sg_io_hdr *hdr, const void __user *argp);
896 extern int put_sg_io_hdr(const struct sg_io_hdr *hdr, void __user *argp);
897 
898 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
899 extern void blk_queue_exit(struct request_queue *q);
900 extern void blk_sync_queue(struct request_queue *q);
901 extern int blk_rq_map_user(struct request_queue *, struct request *,
902 			   struct rq_map_data *, void __user *, unsigned long,
903 			   gfp_t);
904 extern int blk_rq_unmap_user(struct bio *);
905 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
906 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
907 			       struct rq_map_data *, const struct iov_iter *,
908 			       gfp_t);
909 extern void blk_execute_rq_nowait(struct gendisk *,
910 				  struct request *, int, rq_end_io_fn *);
911 
912 blk_status_t blk_execute_rq(struct gendisk *bd_disk, struct request *rq,
913 			    int at_head);
914 
915 /* Helper to convert REQ_OP_XXX to its string format XXX */
916 extern const char *blk_op_str(unsigned int op);
917 
918 int blk_status_to_errno(blk_status_t status);
919 blk_status_t errno_to_blk_status(int errno);
920 
921 int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin);
922 
923 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
924 {
925 	return bdev->bd_disk->queue;	/* this is never NULL */
926 }
927 
928 /*
929  * The basic unit of block I/O is a sector. It is used in a number of contexts
930  * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
931  * bytes. Variables of type sector_t represent an offset or size that is a
932  * multiple of 512 bytes. Hence these two constants.
933  */
934 #ifndef SECTOR_SHIFT
935 #define SECTOR_SHIFT 9
936 #endif
937 #ifndef SECTOR_SIZE
938 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
939 #endif
940 
941 #define PAGE_SECTORS_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
942 #define PAGE_SECTORS		(1 << PAGE_SECTORS_SHIFT)
943 #define SECTOR_MASK		(PAGE_SECTORS - 1)
944 
945 /*
946  * blk_rq_pos()			: the current sector
947  * blk_rq_bytes()		: bytes left in the entire request
948  * blk_rq_cur_bytes()		: bytes left in the current segment
949  * blk_rq_err_bytes()		: bytes left till the next error boundary
950  * blk_rq_sectors()		: sectors left in the entire request
951  * blk_rq_cur_sectors()		: sectors left in the current segment
952  * blk_rq_stats_sectors()	: sectors of the entire request used for stats
953  */
954 static inline sector_t blk_rq_pos(const struct request *rq)
955 {
956 	return rq->__sector;
957 }
958 
959 static inline unsigned int blk_rq_bytes(const struct request *rq)
960 {
961 	return rq->__data_len;
962 }
963 
964 static inline int blk_rq_cur_bytes(const struct request *rq)
965 {
966 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
967 }
968 
969 extern unsigned int blk_rq_err_bytes(const struct request *rq);
970 
971 static inline unsigned int blk_rq_sectors(const struct request *rq)
972 {
973 	return blk_rq_bytes(rq) >> SECTOR_SHIFT;
974 }
975 
976 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
977 {
978 	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
979 }
980 
981 static inline unsigned int blk_rq_stats_sectors(const struct request *rq)
982 {
983 	return rq->stats_sectors;
984 }
985 
986 #ifdef CONFIG_BLK_DEV_ZONED
987 
988 /* Helper to convert BLK_ZONE_ZONE_XXX to its string format XXX */
989 const char *blk_zone_cond_str(enum blk_zone_cond zone_cond);
990 
991 static inline unsigned int bio_zone_no(struct bio *bio)
992 {
993 	return blk_queue_zone_no(bdev_get_queue(bio->bi_bdev),
994 				 bio->bi_iter.bi_sector);
995 }
996 
997 static inline unsigned int bio_zone_is_seq(struct bio *bio)
998 {
999 	return blk_queue_zone_is_seq(bdev_get_queue(bio->bi_bdev),
1000 				     bio->bi_iter.bi_sector);
1001 }
1002 
1003 static inline unsigned int blk_rq_zone_no(struct request *rq)
1004 {
1005 	return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
1006 }
1007 
1008 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
1009 {
1010 	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
1011 }
1012 #endif /* CONFIG_BLK_DEV_ZONED */
1013 
1014 /*
1015  * Some commands like WRITE SAME have a payload or data transfer size which
1016  * is different from the size of the request.  Any driver that supports such
1017  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
1018  * calculate the data transfer size.
1019  */
1020 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
1021 {
1022 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1023 		return rq->special_vec.bv_len;
1024 	return blk_rq_bytes(rq);
1025 }
1026 
1027 /*
1028  * Return the first full biovec in the request.  The caller needs to check that
1029  * there are any bvecs before calling this helper.
1030  */
1031 static inline struct bio_vec req_bvec(struct request *rq)
1032 {
1033 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1034 		return rq->special_vec;
1035 	return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
1036 }
1037 
1038 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
1039 						     int op)
1040 {
1041 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
1042 		return min(q->limits.max_discard_sectors,
1043 			   UINT_MAX >> SECTOR_SHIFT);
1044 
1045 	if (unlikely(op == REQ_OP_WRITE_SAME))
1046 		return q->limits.max_write_same_sectors;
1047 
1048 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
1049 		return q->limits.max_write_zeroes_sectors;
1050 
1051 	return q->limits.max_sectors;
1052 }
1053 
1054 /*
1055  * Return maximum size of a request at given offset. Only valid for
1056  * file system requests.
1057  */
1058 static inline unsigned int blk_max_size_offset(struct request_queue *q,
1059 					       sector_t offset,
1060 					       unsigned int chunk_sectors)
1061 {
1062 	if (!chunk_sectors) {
1063 		if (q->limits.chunk_sectors)
1064 			chunk_sectors = q->limits.chunk_sectors;
1065 		else
1066 			return q->limits.max_sectors;
1067 	}
1068 
1069 	if (likely(is_power_of_2(chunk_sectors)))
1070 		chunk_sectors -= offset & (chunk_sectors - 1);
1071 	else
1072 		chunk_sectors -= sector_div(offset, chunk_sectors);
1073 
1074 	return min(q->limits.max_sectors, chunk_sectors);
1075 }
1076 
1077 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
1078 						  sector_t offset)
1079 {
1080 	struct request_queue *q = rq->q;
1081 
1082 	if (blk_rq_is_passthrough(rq))
1083 		return q->limits.max_hw_sectors;
1084 
1085 	if (!q->limits.chunk_sectors ||
1086 	    req_op(rq) == REQ_OP_DISCARD ||
1087 	    req_op(rq) == REQ_OP_SECURE_ERASE)
1088 		return blk_queue_get_max_sectors(q, req_op(rq));
1089 
1090 	return min(blk_max_size_offset(q, offset, 0),
1091 			blk_queue_get_max_sectors(q, req_op(rq)));
1092 }
1093 
1094 static inline unsigned int blk_rq_count_bios(struct request *rq)
1095 {
1096 	unsigned int nr_bios = 0;
1097 	struct bio *bio;
1098 
1099 	__rq_for_each_bio(bio, rq)
1100 		nr_bios++;
1101 
1102 	return nr_bios;
1103 }
1104 
1105 void blk_steal_bios(struct bio_list *list, struct request *rq);
1106 
1107 /*
1108  * Request completion related functions.
1109  *
1110  * blk_update_request() completes given number of bytes and updates
1111  * the request without completing it.
1112  */
1113 extern bool blk_update_request(struct request *rq, blk_status_t error,
1114 			       unsigned int nr_bytes);
1115 
1116 extern void blk_abort_request(struct request *);
1117 
1118 /*
1119  * Access functions for manipulating queue properties
1120  */
1121 extern void blk_cleanup_queue(struct request_queue *);
1122 void blk_queue_bounce_limit(struct request_queue *q, enum blk_bounce limit);
1123 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1124 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1125 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1126 extern void blk_queue_max_discard_segments(struct request_queue *,
1127 		unsigned short);
1128 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1129 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1130 		unsigned int max_discard_sectors);
1131 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1132 		unsigned int max_write_same_sectors);
1133 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1134 		unsigned int max_write_same_sectors);
1135 extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
1136 extern void blk_queue_max_zone_append_sectors(struct request_queue *q,
1137 		unsigned int max_zone_append_sectors);
1138 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1139 void blk_queue_zone_write_granularity(struct request_queue *q,
1140 				      unsigned int size);
1141 extern void blk_queue_alignment_offset(struct request_queue *q,
1142 				       unsigned int alignment);
1143 void disk_update_readahead(struct gendisk *disk);
1144 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1145 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1146 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1147 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1148 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1149 extern void blk_set_default_limits(struct queue_limits *lim);
1150 extern void blk_set_stacking_limits(struct queue_limits *lim);
1151 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1152 			    sector_t offset);
1153 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1154 			      sector_t offset);
1155 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1156 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1157 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1158 extern void blk_queue_dma_alignment(struct request_queue *, int);
1159 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1160 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1161 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1162 extern void blk_queue_required_elevator_features(struct request_queue *q,
1163 						 unsigned int features);
1164 extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
1165 					      struct device *dev);
1166 
1167 /*
1168  * Number of physical segments as sent to the device.
1169  *
1170  * Normally this is the number of discontiguous data segments sent by the
1171  * submitter.  But for data-less command like discard we might have no
1172  * actual data segments submitted, but the driver might have to add it's
1173  * own special payload.  In that case we still return 1 here so that this
1174  * special payload will be mapped.
1175  */
1176 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1177 {
1178 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1179 		return 1;
1180 	return rq->nr_phys_segments;
1181 }
1182 
1183 /*
1184  * Number of discard segments (or ranges) the driver needs to fill in.
1185  * Each discard bio merged into a request is counted as one segment.
1186  */
1187 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1188 {
1189 	return max_t(unsigned short, rq->nr_phys_segments, 1);
1190 }
1191 
1192 int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
1193 		struct scatterlist *sglist, struct scatterlist **last_sg);
1194 static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq,
1195 		struct scatterlist *sglist)
1196 {
1197 	struct scatterlist *last_sg = NULL;
1198 
1199 	return __blk_rq_map_sg(q, rq, sglist, &last_sg);
1200 }
1201 extern void blk_dump_rq_flags(struct request *, char *);
1202 
1203 bool __must_check blk_get_queue(struct request_queue *);
1204 extern void blk_put_queue(struct request_queue *);
1205 extern void blk_set_queue_dying(struct request_queue *);
1206 
1207 #ifdef CONFIG_BLOCK
1208 /*
1209  * blk_plug permits building a queue of related requests by holding the I/O
1210  * fragments for a short period. This allows merging of sequential requests
1211  * into single larger request. As the requests are moved from a per-task list to
1212  * the device's request_queue in a batch, this results in improved scalability
1213  * as the lock contention for request_queue lock is reduced.
1214  *
1215  * It is ok not to disable preemption when adding the request to the plug list
1216  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1217  * the plug list when the task sleeps by itself. For details, please see
1218  * schedule() where blk_schedule_flush_plug() is called.
1219  */
1220 struct blk_plug {
1221 	struct list_head mq_list; /* blk-mq requests */
1222 	struct list_head cb_list; /* md requires an unplug callback */
1223 	unsigned short rq_count;
1224 	bool multiple_queues;
1225 	bool nowait;
1226 };
1227 #define BLK_MAX_REQUEST_COUNT 16
1228 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1229 
1230 struct blk_plug_cb;
1231 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1232 struct blk_plug_cb {
1233 	struct list_head list;
1234 	blk_plug_cb_fn callback;
1235 	void *data;
1236 };
1237 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1238 					     void *data, int size);
1239 extern void blk_start_plug(struct blk_plug *);
1240 extern void blk_finish_plug(struct blk_plug *);
1241 extern void blk_flush_plug_list(struct blk_plug *, bool);
1242 
1243 static inline void blk_flush_plug(struct task_struct *tsk)
1244 {
1245 	struct blk_plug *plug = tsk->plug;
1246 
1247 	if (plug)
1248 		blk_flush_plug_list(plug, false);
1249 }
1250 
1251 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1252 {
1253 	struct blk_plug *plug = tsk->plug;
1254 
1255 	if (plug)
1256 		blk_flush_plug_list(plug, true);
1257 }
1258 
1259 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1260 {
1261 	struct blk_plug *plug = tsk->plug;
1262 
1263 	return plug &&
1264 		 (!list_empty(&plug->mq_list) ||
1265 		 !list_empty(&plug->cb_list));
1266 }
1267 
1268 int blkdev_issue_flush(struct block_device *bdev);
1269 long nr_blockdev_pages(void);
1270 #else /* CONFIG_BLOCK */
1271 struct blk_plug {
1272 };
1273 
1274 static inline void blk_start_plug(struct blk_plug *plug)
1275 {
1276 }
1277 
1278 static inline void blk_finish_plug(struct blk_plug *plug)
1279 {
1280 }
1281 
1282 static inline void blk_flush_plug(struct task_struct *task)
1283 {
1284 }
1285 
1286 static inline void blk_schedule_flush_plug(struct task_struct *task)
1287 {
1288 }
1289 
1290 
1291 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1292 {
1293 	return false;
1294 }
1295 
1296 static inline int blkdev_issue_flush(struct block_device *bdev)
1297 {
1298 	return 0;
1299 }
1300 
1301 static inline long nr_blockdev_pages(void)
1302 {
1303 	return 0;
1304 }
1305 #endif /* CONFIG_BLOCK */
1306 
1307 extern void blk_io_schedule(void);
1308 
1309 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1310 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1311 
1312 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
1313 
1314 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1315 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1316 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1317 		sector_t nr_sects, gfp_t gfp_mask, int flags,
1318 		struct bio **biop);
1319 
1320 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
1321 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
1322 
1323 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1324 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1325 		unsigned flags);
1326 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1327 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1328 
1329 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1330 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1331 {
1332 	return blkdev_issue_discard(sb->s_bdev,
1333 				    block << (sb->s_blocksize_bits -
1334 					      SECTOR_SHIFT),
1335 				    nr_blocks << (sb->s_blocksize_bits -
1336 						  SECTOR_SHIFT),
1337 				    gfp_mask, flags);
1338 }
1339 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1340 		sector_t nr_blocks, gfp_t gfp_mask)
1341 {
1342 	return blkdev_issue_zeroout(sb->s_bdev,
1343 				    block << (sb->s_blocksize_bits -
1344 					      SECTOR_SHIFT),
1345 				    nr_blocks << (sb->s_blocksize_bits -
1346 						  SECTOR_SHIFT),
1347 				    gfp_mask, 0);
1348 }
1349 
1350 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1351 
1352 static inline bool bdev_is_partition(struct block_device *bdev)
1353 {
1354 	return bdev->bd_partno;
1355 }
1356 
1357 enum blk_default_limits {
1358 	BLK_MAX_SEGMENTS	= 128,
1359 	BLK_SAFE_MAX_SECTORS	= 255,
1360 	BLK_DEF_MAX_SECTORS	= 2560,
1361 	BLK_MAX_SEGMENT_SIZE	= 65536,
1362 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
1363 };
1364 
1365 static inline unsigned long queue_segment_boundary(const struct request_queue *q)
1366 {
1367 	return q->limits.seg_boundary_mask;
1368 }
1369 
1370 static inline unsigned long queue_virt_boundary(const struct request_queue *q)
1371 {
1372 	return q->limits.virt_boundary_mask;
1373 }
1374 
1375 static inline unsigned int queue_max_sectors(const struct request_queue *q)
1376 {
1377 	return q->limits.max_sectors;
1378 }
1379 
1380 static inline unsigned int queue_max_hw_sectors(const struct request_queue *q)
1381 {
1382 	return q->limits.max_hw_sectors;
1383 }
1384 
1385 static inline unsigned short queue_max_segments(const struct request_queue *q)
1386 {
1387 	return q->limits.max_segments;
1388 }
1389 
1390 static inline unsigned short queue_max_discard_segments(const struct request_queue *q)
1391 {
1392 	return q->limits.max_discard_segments;
1393 }
1394 
1395 static inline unsigned int queue_max_segment_size(const struct request_queue *q)
1396 {
1397 	return q->limits.max_segment_size;
1398 }
1399 
1400 static inline unsigned int queue_max_zone_append_sectors(const struct request_queue *q)
1401 {
1402 
1403 	const struct queue_limits *l = &q->limits;
1404 
1405 	return min(l->max_zone_append_sectors, l->max_sectors);
1406 }
1407 
1408 static inline unsigned queue_logical_block_size(const struct request_queue *q)
1409 {
1410 	int retval = 512;
1411 
1412 	if (q && q->limits.logical_block_size)
1413 		retval = q->limits.logical_block_size;
1414 
1415 	return retval;
1416 }
1417 
1418 static inline unsigned int bdev_logical_block_size(struct block_device *bdev)
1419 {
1420 	return queue_logical_block_size(bdev_get_queue(bdev));
1421 }
1422 
1423 static inline unsigned int queue_physical_block_size(const struct request_queue *q)
1424 {
1425 	return q->limits.physical_block_size;
1426 }
1427 
1428 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1429 {
1430 	return queue_physical_block_size(bdev_get_queue(bdev));
1431 }
1432 
1433 static inline unsigned int queue_io_min(const struct request_queue *q)
1434 {
1435 	return q->limits.io_min;
1436 }
1437 
1438 static inline int bdev_io_min(struct block_device *bdev)
1439 {
1440 	return queue_io_min(bdev_get_queue(bdev));
1441 }
1442 
1443 static inline unsigned int queue_io_opt(const struct request_queue *q)
1444 {
1445 	return q->limits.io_opt;
1446 }
1447 
1448 static inline int bdev_io_opt(struct block_device *bdev)
1449 {
1450 	return queue_io_opt(bdev_get_queue(bdev));
1451 }
1452 
1453 static inline unsigned int
1454 queue_zone_write_granularity(const struct request_queue *q)
1455 {
1456 	return q->limits.zone_write_granularity;
1457 }
1458 
1459 static inline unsigned int
1460 bdev_zone_write_granularity(struct block_device *bdev)
1461 {
1462 	return queue_zone_write_granularity(bdev_get_queue(bdev));
1463 }
1464 
1465 static inline int queue_alignment_offset(const struct request_queue *q)
1466 {
1467 	if (q->limits.misaligned)
1468 		return -1;
1469 
1470 	return q->limits.alignment_offset;
1471 }
1472 
1473 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1474 {
1475 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1476 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1477 		<< SECTOR_SHIFT;
1478 
1479 	return (granularity + lim->alignment_offset - alignment) % granularity;
1480 }
1481 
1482 static inline int bdev_alignment_offset(struct block_device *bdev)
1483 {
1484 	struct request_queue *q = bdev_get_queue(bdev);
1485 
1486 	if (q->limits.misaligned)
1487 		return -1;
1488 	if (bdev_is_partition(bdev))
1489 		return queue_limit_alignment_offset(&q->limits,
1490 				bdev->bd_start_sect);
1491 	return q->limits.alignment_offset;
1492 }
1493 
1494 static inline int queue_discard_alignment(const struct request_queue *q)
1495 {
1496 	if (q->limits.discard_misaligned)
1497 		return -1;
1498 
1499 	return q->limits.discard_alignment;
1500 }
1501 
1502 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1503 {
1504 	unsigned int alignment, granularity, offset;
1505 
1506 	if (!lim->max_discard_sectors)
1507 		return 0;
1508 
1509 	/* Why are these in bytes, not sectors? */
1510 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
1511 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
1512 	if (!granularity)
1513 		return 0;
1514 
1515 	/* Offset of the partition start in 'granularity' sectors */
1516 	offset = sector_div(sector, granularity);
1517 
1518 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
1519 	offset = (granularity + alignment - offset) % granularity;
1520 
1521 	/* Turn it back into bytes, gaah */
1522 	return offset << SECTOR_SHIFT;
1523 }
1524 
1525 /*
1526  * Two cases of handling DISCARD merge:
1527  * If max_discard_segments > 1, the driver takes every bio
1528  * as a range and send them to controller together. The ranges
1529  * needn't to be contiguous.
1530  * Otherwise, the bios/requests will be handled as same as
1531  * others which should be contiguous.
1532  */
1533 static inline bool blk_discard_mergable(struct request *req)
1534 {
1535 	if (req_op(req) == REQ_OP_DISCARD &&
1536 	    queue_max_discard_segments(req->q) > 1)
1537 		return true;
1538 	return false;
1539 }
1540 
1541 static inline int bdev_discard_alignment(struct block_device *bdev)
1542 {
1543 	struct request_queue *q = bdev_get_queue(bdev);
1544 
1545 	if (bdev_is_partition(bdev))
1546 		return queue_limit_discard_alignment(&q->limits,
1547 				bdev->bd_start_sect);
1548 	return q->limits.discard_alignment;
1549 }
1550 
1551 static inline unsigned int bdev_write_same(struct block_device *bdev)
1552 {
1553 	struct request_queue *q = bdev_get_queue(bdev);
1554 
1555 	if (q)
1556 		return q->limits.max_write_same_sectors;
1557 
1558 	return 0;
1559 }
1560 
1561 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1562 {
1563 	struct request_queue *q = bdev_get_queue(bdev);
1564 
1565 	if (q)
1566 		return q->limits.max_write_zeroes_sectors;
1567 
1568 	return 0;
1569 }
1570 
1571 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1572 {
1573 	struct request_queue *q = bdev_get_queue(bdev);
1574 
1575 	if (q)
1576 		return blk_queue_zoned_model(q);
1577 
1578 	return BLK_ZONED_NONE;
1579 }
1580 
1581 static inline bool bdev_is_zoned(struct block_device *bdev)
1582 {
1583 	struct request_queue *q = bdev_get_queue(bdev);
1584 
1585 	if (q)
1586 		return blk_queue_is_zoned(q);
1587 
1588 	return false;
1589 }
1590 
1591 static inline sector_t bdev_zone_sectors(struct block_device *bdev)
1592 {
1593 	struct request_queue *q = bdev_get_queue(bdev);
1594 
1595 	if (q)
1596 		return blk_queue_zone_sectors(q);
1597 	return 0;
1598 }
1599 
1600 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
1601 {
1602 	struct request_queue *q = bdev_get_queue(bdev);
1603 
1604 	if (q)
1605 		return queue_max_open_zones(q);
1606 	return 0;
1607 }
1608 
1609 static inline unsigned int bdev_max_active_zones(struct block_device *bdev)
1610 {
1611 	struct request_queue *q = bdev_get_queue(bdev);
1612 
1613 	if (q)
1614 		return queue_max_active_zones(q);
1615 	return 0;
1616 }
1617 
1618 static inline int queue_dma_alignment(const struct request_queue *q)
1619 {
1620 	return q ? q->dma_alignment : 511;
1621 }
1622 
1623 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1624 				 unsigned int len)
1625 {
1626 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1627 	return !(addr & alignment) && !(len & alignment);
1628 }
1629 
1630 /* assumes size > 256 */
1631 static inline unsigned int blksize_bits(unsigned int size)
1632 {
1633 	unsigned int bits = 8;
1634 	do {
1635 		bits++;
1636 		size >>= 1;
1637 	} while (size > 256);
1638 	return bits;
1639 }
1640 
1641 static inline unsigned int block_size(struct block_device *bdev)
1642 {
1643 	return 1 << bdev->bd_inode->i_blkbits;
1644 }
1645 
1646 int kblockd_schedule_work(struct work_struct *work);
1647 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1648 
1649 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1650 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1651 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1652 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1653 
1654 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1655 
1656 enum blk_integrity_flags {
1657 	BLK_INTEGRITY_VERIFY		= 1 << 0,
1658 	BLK_INTEGRITY_GENERATE		= 1 << 1,
1659 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
1660 	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
1661 };
1662 
1663 struct blk_integrity_iter {
1664 	void			*prot_buf;
1665 	void			*data_buf;
1666 	sector_t		seed;
1667 	unsigned int		data_size;
1668 	unsigned short		interval;
1669 	const char		*disk_name;
1670 };
1671 
1672 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1673 typedef void (integrity_prepare_fn) (struct request *);
1674 typedef void (integrity_complete_fn) (struct request *, unsigned int);
1675 
1676 struct blk_integrity_profile {
1677 	integrity_processing_fn		*generate_fn;
1678 	integrity_processing_fn		*verify_fn;
1679 	integrity_prepare_fn		*prepare_fn;
1680 	integrity_complete_fn		*complete_fn;
1681 	const char			*name;
1682 };
1683 
1684 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1685 extern void blk_integrity_unregister(struct gendisk *);
1686 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1687 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1688 				   struct scatterlist *);
1689 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1690 
1691 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1692 {
1693 	struct blk_integrity *bi = &disk->queue->integrity;
1694 
1695 	if (!bi->profile)
1696 		return NULL;
1697 
1698 	return bi;
1699 }
1700 
1701 static inline
1702 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1703 {
1704 	return blk_get_integrity(bdev->bd_disk);
1705 }
1706 
1707 static inline bool
1708 blk_integrity_queue_supports_integrity(struct request_queue *q)
1709 {
1710 	return q->integrity.profile;
1711 }
1712 
1713 static inline bool blk_integrity_rq(struct request *rq)
1714 {
1715 	return rq->cmd_flags & REQ_INTEGRITY;
1716 }
1717 
1718 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1719 						    unsigned int segs)
1720 {
1721 	q->limits.max_integrity_segments = segs;
1722 }
1723 
1724 static inline unsigned short
1725 queue_max_integrity_segments(const struct request_queue *q)
1726 {
1727 	return q->limits.max_integrity_segments;
1728 }
1729 
1730 /**
1731  * bio_integrity_intervals - Return number of integrity intervals for a bio
1732  * @bi:		blk_integrity profile for device
1733  * @sectors:	Size of the bio in 512-byte sectors
1734  *
1735  * Description: The block layer calculates everything in 512 byte
1736  * sectors but integrity metadata is done in terms of the data integrity
1737  * interval size of the storage device.  Convert the block layer sectors
1738  * to the appropriate number of integrity intervals.
1739  */
1740 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1741 						   unsigned int sectors)
1742 {
1743 	return sectors >> (bi->interval_exp - 9);
1744 }
1745 
1746 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1747 					       unsigned int sectors)
1748 {
1749 	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
1750 }
1751 
1752 /*
1753  * Return the first bvec that contains integrity data.  Only drivers that are
1754  * limited to a single integrity segment should use this helper.
1755  */
1756 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1757 {
1758 	if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
1759 		return NULL;
1760 	return rq->bio->bi_integrity->bip_vec;
1761 }
1762 
1763 #else /* CONFIG_BLK_DEV_INTEGRITY */
1764 
1765 struct bio;
1766 struct block_device;
1767 struct gendisk;
1768 struct blk_integrity;
1769 
1770 static inline int blk_integrity_rq(struct request *rq)
1771 {
1772 	return 0;
1773 }
1774 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1775 					    struct bio *b)
1776 {
1777 	return 0;
1778 }
1779 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1780 					  struct bio *b,
1781 					  struct scatterlist *s)
1782 {
1783 	return 0;
1784 }
1785 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1786 {
1787 	return NULL;
1788 }
1789 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1790 {
1791 	return NULL;
1792 }
1793 static inline bool
1794 blk_integrity_queue_supports_integrity(struct request_queue *q)
1795 {
1796 	return false;
1797 }
1798 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1799 {
1800 	return 0;
1801 }
1802 static inline void blk_integrity_register(struct gendisk *d,
1803 					 struct blk_integrity *b)
1804 {
1805 }
1806 static inline void blk_integrity_unregister(struct gendisk *d)
1807 {
1808 }
1809 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1810 						    unsigned int segs)
1811 {
1812 }
1813 static inline unsigned short queue_max_integrity_segments(const struct request_queue *q)
1814 {
1815 	return 0;
1816 }
1817 
1818 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1819 						   unsigned int sectors)
1820 {
1821 	return 0;
1822 }
1823 
1824 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1825 					       unsigned int sectors)
1826 {
1827 	return 0;
1828 }
1829 
1830 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1831 {
1832 	return NULL;
1833 }
1834 
1835 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1836 
1837 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1838 
1839 bool blk_ksm_register(struct blk_keyslot_manager *ksm, struct request_queue *q);
1840 
1841 void blk_ksm_unregister(struct request_queue *q);
1842 
1843 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1844 
1845 static inline bool blk_ksm_register(struct blk_keyslot_manager *ksm,
1846 				    struct request_queue *q)
1847 {
1848 	return true;
1849 }
1850 
1851 static inline void blk_ksm_unregister(struct request_queue *q) { }
1852 
1853 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
1854 
1855 
1856 struct block_device_operations {
1857 	blk_qc_t (*submit_bio) (struct bio *bio);
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 	void (*unlock_native_capacity) (struct gendisk *);
1866 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1867 	int (*set_read_only)(struct block_device *bdev, bool ro);
1868 	/* this callback is with swap_lock and sometimes page table lock held */
1869 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1870 	int (*report_zones)(struct gendisk *, sector_t sector,
1871 			unsigned int nr_zones, report_zones_cb cb, void *data);
1872 	char *(*devnode)(struct gendisk *disk, umode_t *mode);
1873 	struct module *owner;
1874 	const struct pr_ops *pr_ops;
1875 
1876 	/*
1877 	 * Special callback for probing GPT entry at a given sector.
1878 	 * Needed by Android devices, used by GPT scanner and MMC blk
1879 	 * driver.
1880 	 */
1881 	int (*alternative_gpt_sector)(struct gendisk *disk, sector_t *sector);
1882 };
1883 
1884 #ifdef CONFIG_COMPAT
1885 extern int blkdev_compat_ptr_ioctl(struct block_device *, fmode_t,
1886 				      unsigned int, unsigned long);
1887 #else
1888 #define blkdev_compat_ptr_ioctl NULL
1889 #endif
1890 
1891 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1892 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1893 						struct writeback_control *);
1894 
1895 #ifdef CONFIG_BLK_DEV_ZONED
1896 bool blk_req_needs_zone_write_lock(struct request *rq);
1897 bool blk_req_zone_write_trylock(struct request *rq);
1898 void __blk_req_zone_write_lock(struct request *rq);
1899 void __blk_req_zone_write_unlock(struct request *rq);
1900 
1901 static inline void blk_req_zone_write_lock(struct request *rq)
1902 {
1903 	if (blk_req_needs_zone_write_lock(rq))
1904 		__blk_req_zone_write_lock(rq);
1905 }
1906 
1907 static inline void blk_req_zone_write_unlock(struct request *rq)
1908 {
1909 	if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
1910 		__blk_req_zone_write_unlock(rq);
1911 }
1912 
1913 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1914 {
1915 	return rq->q->seq_zones_wlock &&
1916 		test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
1917 }
1918 
1919 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1920 {
1921 	if (!blk_req_needs_zone_write_lock(rq))
1922 		return true;
1923 	return !blk_req_zone_is_write_locked(rq);
1924 }
1925 #else
1926 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
1927 {
1928 	return false;
1929 }
1930 
1931 static inline void blk_req_zone_write_lock(struct request *rq)
1932 {
1933 }
1934 
1935 static inline void blk_req_zone_write_unlock(struct request *rq)
1936 {
1937 }
1938 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1939 {
1940 	return false;
1941 }
1942 
1943 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1944 {
1945 	return true;
1946 }
1947 #endif /* CONFIG_BLK_DEV_ZONED */
1948 
1949 static inline void blk_wake_io_task(struct task_struct *waiter)
1950 {
1951 	/*
1952 	 * If we're polling, the task itself is doing the completions. For
1953 	 * that case, we don't need to signal a wakeup, it's enough to just
1954 	 * mark us as RUNNING.
1955 	 */
1956 	if (waiter == current)
1957 		__set_current_state(TASK_RUNNING);
1958 	else
1959 		wake_up_process(waiter);
1960 }
1961 
1962 unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
1963 		unsigned int op);
1964 void disk_end_io_acct(struct gendisk *disk, unsigned int op,
1965 		unsigned long start_time);
1966 
1967 unsigned long bio_start_io_acct(struct bio *bio);
1968 void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time,
1969 		struct block_device *orig_bdev);
1970 
1971 /**
1972  * bio_end_io_acct - end I/O accounting for bio based drivers
1973  * @bio:	bio to end account for
1974  * @start:	start time returned by bio_start_io_acct()
1975  */
1976 static inline void bio_end_io_acct(struct bio *bio, unsigned long start_time)
1977 {
1978 	return bio_end_io_acct_remapped(bio, start_time, bio->bi_bdev);
1979 }
1980 
1981 int bdev_read_only(struct block_device *bdev);
1982 int set_blocksize(struct block_device *bdev, int size);
1983 
1984 const char *bdevname(struct block_device *bdev, char *buffer);
1985 int lookup_bdev(const char *pathname, dev_t *dev);
1986 
1987 void blkdev_show(struct seq_file *seqf, off_t offset);
1988 
1989 #define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
1990 #define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
1991 #ifdef CONFIG_BLOCK
1992 #define BLKDEV_MAJOR_MAX	512
1993 #else
1994 #define BLKDEV_MAJOR_MAX	0
1995 #endif
1996 
1997 struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
1998 		void *holder);
1999 struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
2000 int bd_prepare_to_claim(struct block_device *bdev, void *holder);
2001 void bd_abort_claiming(struct block_device *bdev, void *holder);
2002 void blkdev_put(struct block_device *bdev, fmode_t mode);
2003 
2004 /* just for blk-cgroup, don't use elsewhere */
2005 struct block_device *blkdev_get_no_open(dev_t dev);
2006 void blkdev_put_no_open(struct block_device *bdev);
2007 
2008 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
2009 void bdev_add(struct block_device *bdev, dev_t dev);
2010 struct block_device *I_BDEV(struct inode *inode);
2011 int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart,
2012 		loff_t lend);
2013 
2014 #ifdef CONFIG_BLOCK
2015 void invalidate_bdev(struct block_device *bdev);
2016 int sync_blockdev(struct block_device *bdev);
2017 #else
2018 static inline void invalidate_bdev(struct block_device *bdev)
2019 {
2020 }
2021 static inline int sync_blockdev(struct block_device *bdev)
2022 {
2023 	return 0;
2024 }
2025 #endif
2026 int fsync_bdev(struct block_device *bdev);
2027 
2028 int freeze_bdev(struct block_device *bdev);
2029 int thaw_bdev(struct block_device *bdev);
2030 
2031 #endif /* _LINUX_BLKDEV_H */
2032