xref: /linux-6.15/include/linux/blkdev.h (revision e00a844a)
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_wb;
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 consisitent 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		3
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 I/O stat */
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 /* IO stats tracking on */
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 
125 /* flags that prevent us from merging requests: */
126 #define RQF_NOMERGE_FLAGS \
127 	(RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
128 
129 /*
130  * Try to put the fields that are referenced together in the same cacheline.
131  *
132  * If you modify this structure, make sure to update blk_rq_init() and
133  * especially blk_mq_rq_ctx_init() to take care of the added fields.
134  */
135 struct request {
136 	struct list_head queuelist;
137 	union {
138 		call_single_data_t csd;
139 		u64 fifo_time;
140 	};
141 
142 	struct request_queue *q;
143 	struct blk_mq_ctx *mq_ctx;
144 
145 	int cpu;
146 	unsigned int cmd_flags;		/* op and common flags */
147 	req_flags_t rq_flags;
148 
149 	int internal_tag;
150 
151 	unsigned long atomic_flags;
152 
153 	/* the following two fields are internal, NEVER access directly */
154 	unsigned int __data_len;	/* total data len */
155 	int tag;
156 	sector_t __sector;		/* sector cursor */
157 
158 	struct bio *bio;
159 	struct bio *biotail;
160 
161 	/*
162 	 * The hash is used inside the scheduler, and killed once the
163 	 * request reaches the dispatch list. The ipi_list is only used
164 	 * to queue the request for softirq completion, which is long
165 	 * after the request has been unhashed (and even removed from
166 	 * the dispatch list).
167 	 */
168 	union {
169 		struct hlist_node hash;	/* merge hash */
170 		struct list_head ipi_list;
171 	};
172 
173 	/*
174 	 * The rb_node is only used inside the io scheduler, requests
175 	 * are pruned when moved to the dispatch queue. So let the
176 	 * completion_data share space with the rb_node.
177 	 */
178 	union {
179 		struct rb_node rb_node;	/* sort/lookup */
180 		struct bio_vec special_vec;
181 		void *completion_data;
182 		int error_count; /* for legacy drivers, don't use */
183 	};
184 
185 	/*
186 	 * Three pointers are available for the IO schedulers, if they need
187 	 * more they have to dynamically allocate it.  Flush requests are
188 	 * never put on the IO scheduler. So let the flush fields share
189 	 * space with the elevator data.
190 	 */
191 	union {
192 		struct {
193 			struct io_cq		*icq;
194 			void			*priv[2];
195 		} elv;
196 
197 		struct {
198 			unsigned int		seq;
199 			struct list_head	list;
200 			rq_end_io_fn		*saved_end_io;
201 		} flush;
202 	};
203 
204 	struct gendisk *rq_disk;
205 	struct hd_struct *part;
206 	unsigned long start_time;
207 	struct blk_issue_stat issue_stat;
208 #ifdef CONFIG_BLK_CGROUP
209 	struct request_list *rl;		/* rl this rq is alloced from */
210 	unsigned long long start_time_ns;
211 	unsigned long long io_start_time_ns;    /* when passed to hardware */
212 #endif
213 	/* Number of scatter-gather DMA addr+len pairs after
214 	 * physical address coalescing is performed.
215 	 */
216 	unsigned short nr_phys_segments;
217 #if defined(CONFIG_BLK_DEV_INTEGRITY)
218 	unsigned short nr_integrity_segments;
219 #endif
220 
221 	unsigned short ioprio;
222 
223 	unsigned int timeout;
224 
225 	void *special;		/* opaque pointer available for LLD use */
226 
227 	unsigned int extra_len;	/* length of alignment and padding */
228 
229 	unsigned short write_hint;
230 
231 	unsigned long deadline;
232 	struct list_head timeout_list;
233 
234 	/*
235 	 * completion callback.
236 	 */
237 	rq_end_io_fn *end_io;
238 	void *end_io_data;
239 
240 	/* for bidi */
241 	struct request *next_rq;
242 };
243 
244 static inline bool blk_rq_is_scsi(struct request *rq)
245 {
246 	return req_op(rq) == REQ_OP_SCSI_IN || req_op(rq) == REQ_OP_SCSI_OUT;
247 }
248 
249 static inline bool blk_rq_is_private(struct request *rq)
250 {
251 	return req_op(rq) == REQ_OP_DRV_IN || req_op(rq) == REQ_OP_DRV_OUT;
252 }
253 
254 static inline bool blk_rq_is_passthrough(struct request *rq)
255 {
256 	return blk_rq_is_scsi(rq) || blk_rq_is_private(rq);
257 }
258 
259 static inline unsigned short req_get_ioprio(struct request *req)
260 {
261 	return req->ioprio;
262 }
263 
264 #include <linux/elevator.h>
265 
266 struct blk_queue_ctx;
267 
268 typedef void (request_fn_proc) (struct request_queue *q);
269 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
270 typedef bool (poll_q_fn) (struct request_queue *q, blk_qc_t);
271 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
272 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
273 
274 struct bio_vec;
275 typedef void (softirq_done_fn)(struct request *);
276 typedef int (dma_drain_needed_fn)(struct request *);
277 typedef int (lld_busy_fn) (struct request_queue *q);
278 typedef int (bsg_job_fn) (struct bsg_job *);
279 typedef int (init_rq_fn)(struct request_queue *, struct request *, gfp_t);
280 typedef void (exit_rq_fn)(struct request_queue *, struct request *);
281 
282 enum blk_eh_timer_return {
283 	BLK_EH_NOT_HANDLED,
284 	BLK_EH_HANDLED,
285 	BLK_EH_RESET_TIMER,
286 };
287 
288 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
289 
290 enum blk_queue_state {
291 	Queue_down,
292 	Queue_up,
293 };
294 
295 struct blk_queue_tag {
296 	struct request **tag_index;	/* map of busy tags */
297 	unsigned long *tag_map;		/* bit map of free/busy tags */
298 	int max_depth;			/* what we will send to device */
299 	int real_max_depth;		/* what the array can hold */
300 	atomic_t refcnt;		/* map can be shared */
301 	int alloc_policy;		/* tag allocation policy */
302 	int next_tag;			/* next tag */
303 };
304 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
305 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
306 
307 #define BLK_SCSI_MAX_CMDS	(256)
308 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
309 
310 /*
311  * Zoned block device models (zoned limit).
312  */
313 enum blk_zoned_model {
314 	BLK_ZONED_NONE,	/* Regular block device */
315 	BLK_ZONED_HA,	/* Host-aware zoned block device */
316 	BLK_ZONED_HM,	/* Host-managed zoned block device */
317 };
318 
319 struct queue_limits {
320 	unsigned long		bounce_pfn;
321 	unsigned long		seg_boundary_mask;
322 	unsigned long		virt_boundary_mask;
323 
324 	unsigned int		max_hw_sectors;
325 	unsigned int		max_dev_sectors;
326 	unsigned int		chunk_sectors;
327 	unsigned int		max_sectors;
328 	unsigned int		max_segment_size;
329 	unsigned int		physical_block_size;
330 	unsigned int		alignment_offset;
331 	unsigned int		io_min;
332 	unsigned int		io_opt;
333 	unsigned int		max_discard_sectors;
334 	unsigned int		max_hw_discard_sectors;
335 	unsigned int		max_write_same_sectors;
336 	unsigned int		max_write_zeroes_sectors;
337 	unsigned int		discard_granularity;
338 	unsigned int		discard_alignment;
339 
340 	unsigned short		logical_block_size;
341 	unsigned short		max_segments;
342 	unsigned short		max_integrity_segments;
343 	unsigned short		max_discard_segments;
344 
345 	unsigned char		misaligned;
346 	unsigned char		discard_misaligned;
347 	unsigned char		cluster;
348 	unsigned char		raid_partial_stripes_expensive;
349 	enum blk_zoned_model	zoned;
350 };
351 
352 #ifdef CONFIG_BLK_DEV_ZONED
353 
354 struct blk_zone_report_hdr {
355 	unsigned int	nr_zones;
356 	u8		padding[60];
357 };
358 
359 extern int blkdev_report_zones(struct block_device *bdev,
360 			       sector_t sector, struct blk_zone *zones,
361 			       unsigned int *nr_zones, gfp_t gfp_mask);
362 extern int blkdev_reset_zones(struct block_device *bdev, sector_t sectors,
363 			      sector_t nr_sectors, gfp_t gfp_mask);
364 
365 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
366 				     unsigned int cmd, unsigned long arg);
367 extern int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
368 				    unsigned int cmd, unsigned long arg);
369 
370 #else /* CONFIG_BLK_DEV_ZONED */
371 
372 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
373 					    fmode_t mode, unsigned int cmd,
374 					    unsigned long arg)
375 {
376 	return -ENOTTY;
377 }
378 
379 static inline int blkdev_reset_zones_ioctl(struct block_device *bdev,
380 					   fmode_t mode, unsigned int cmd,
381 					   unsigned long arg)
382 {
383 	return -ENOTTY;
384 }
385 
386 #endif /* CONFIG_BLK_DEV_ZONED */
387 
388 struct request_queue {
389 	/*
390 	 * Together with queue_head for cacheline sharing
391 	 */
392 	struct list_head	queue_head;
393 	struct request		*last_merge;
394 	struct elevator_queue	*elevator;
395 	int			nr_rqs[2];	/* # allocated [a]sync rqs */
396 	int			nr_rqs_elvpriv;	/* # allocated rqs w/ elvpriv */
397 
398 	atomic_t		shared_hctx_restart;
399 
400 	struct blk_queue_stats	*stats;
401 	struct rq_wb		*rq_wb;
402 
403 	/*
404 	 * If blkcg is not used, @q->root_rl serves all requests.  If blkcg
405 	 * is used, root blkg allocates from @q->root_rl and all other
406 	 * blkgs from their own blkg->rl.  Which one to use should be
407 	 * determined using bio_request_list().
408 	 */
409 	struct request_list	root_rl;
410 
411 	request_fn_proc		*request_fn;
412 	make_request_fn		*make_request_fn;
413 	poll_q_fn		*poll_fn;
414 	prep_rq_fn		*prep_rq_fn;
415 	unprep_rq_fn		*unprep_rq_fn;
416 	softirq_done_fn		*softirq_done_fn;
417 	rq_timed_out_fn		*rq_timed_out_fn;
418 	dma_drain_needed_fn	*dma_drain_needed;
419 	lld_busy_fn		*lld_busy_fn;
420 	/* Called just after a request is allocated */
421 	init_rq_fn		*init_rq_fn;
422 	/* Called just before a request is freed */
423 	exit_rq_fn		*exit_rq_fn;
424 	/* Called from inside blk_get_request() */
425 	void (*initialize_rq_fn)(struct request *rq);
426 
427 	const struct blk_mq_ops	*mq_ops;
428 
429 	unsigned int		*mq_map;
430 
431 	/* sw queues */
432 	struct blk_mq_ctx __percpu	*queue_ctx;
433 	unsigned int		nr_queues;
434 
435 	unsigned int		queue_depth;
436 
437 	/* hw dispatch queues */
438 	struct blk_mq_hw_ctx	**queue_hw_ctx;
439 	unsigned int		nr_hw_queues;
440 
441 	/*
442 	 * Dispatch queue sorting
443 	 */
444 	sector_t		end_sector;
445 	struct request		*boundary_rq;
446 
447 	/*
448 	 * Delayed queue handling
449 	 */
450 	struct delayed_work	delay_work;
451 
452 	struct backing_dev_info	*backing_dev_info;
453 
454 	/*
455 	 * The queue owner gets to use this for whatever they like.
456 	 * ll_rw_blk doesn't touch it.
457 	 */
458 	void			*queuedata;
459 
460 	/*
461 	 * various queue flags, see QUEUE_* below
462 	 */
463 	unsigned long		queue_flags;
464 
465 	/*
466 	 * ida allocated id for this queue.  Used to index queues from
467 	 * ioctx.
468 	 */
469 	int			id;
470 
471 	/*
472 	 * queue needs bounce pages for pages above this limit
473 	 */
474 	gfp_t			bounce_gfp;
475 
476 	/*
477 	 * protects queue structures from reentrancy. ->__queue_lock should
478 	 * _never_ be used directly, it is queue private. always use
479 	 * ->queue_lock.
480 	 */
481 	spinlock_t		__queue_lock;
482 	spinlock_t		*queue_lock;
483 
484 	/*
485 	 * queue kobject
486 	 */
487 	struct kobject kobj;
488 
489 	/*
490 	 * mq queue kobject
491 	 */
492 	struct kobject mq_kobj;
493 
494 #ifdef  CONFIG_BLK_DEV_INTEGRITY
495 	struct blk_integrity integrity;
496 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
497 
498 #ifdef CONFIG_PM
499 	struct device		*dev;
500 	int			rpm_status;
501 	unsigned int		nr_pending;
502 #endif
503 
504 	/*
505 	 * queue settings
506 	 */
507 	unsigned long		nr_requests;	/* Max # of requests */
508 	unsigned int		nr_congestion_on;
509 	unsigned int		nr_congestion_off;
510 	unsigned int		nr_batching;
511 
512 	unsigned int		dma_drain_size;
513 	void			*dma_drain_buffer;
514 	unsigned int		dma_pad_mask;
515 	unsigned int		dma_alignment;
516 
517 	struct blk_queue_tag	*queue_tags;
518 	struct list_head	tag_busy_list;
519 
520 	unsigned int		nr_sorted;
521 	unsigned int		in_flight[2];
522 
523 	/*
524 	 * Number of active block driver functions for which blk_drain_queue()
525 	 * must wait. Must be incremented around functions that unlock the
526 	 * queue_lock internally, e.g. scsi_request_fn().
527 	 */
528 	unsigned int		request_fn_active;
529 
530 	unsigned int		rq_timeout;
531 	int			poll_nsec;
532 
533 	struct blk_stat_callback	*poll_cb;
534 	struct blk_rq_stat	poll_stat[BLK_MQ_POLL_STATS_BKTS];
535 
536 	struct timer_list	timeout;
537 	struct work_struct	timeout_work;
538 	struct list_head	timeout_list;
539 
540 	struct list_head	icq_list;
541 #ifdef CONFIG_BLK_CGROUP
542 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
543 	struct blkcg_gq		*root_blkg;
544 	struct list_head	blkg_list;
545 #endif
546 
547 	struct queue_limits	limits;
548 
549 	/*
550 	 * sg stuff
551 	 */
552 	unsigned int		sg_timeout;
553 	unsigned int		sg_reserved_size;
554 	int			node;
555 #ifdef CONFIG_BLK_DEV_IO_TRACE
556 	struct blk_trace	*blk_trace;
557 	struct mutex		blk_trace_mutex;
558 #endif
559 	/*
560 	 * for flush operations
561 	 */
562 	struct blk_flush_queue	*fq;
563 
564 	struct list_head	requeue_list;
565 	spinlock_t		requeue_lock;
566 	struct delayed_work	requeue_work;
567 
568 	struct mutex		sysfs_lock;
569 
570 	int			bypass_depth;
571 	atomic_t		mq_freeze_depth;
572 
573 #if defined(CONFIG_BLK_DEV_BSG)
574 	bsg_job_fn		*bsg_job_fn;
575 	struct bsg_class_device bsg_dev;
576 #endif
577 
578 #ifdef CONFIG_BLK_DEV_THROTTLING
579 	/* Throttle data */
580 	struct throtl_data *td;
581 #endif
582 	struct rcu_head		rcu_head;
583 	wait_queue_head_t	mq_freeze_wq;
584 	struct percpu_ref	q_usage_counter;
585 	struct list_head	all_q_node;
586 
587 	struct blk_mq_tag_set	*tag_set;
588 	struct list_head	tag_set_list;
589 	struct bio_set		*bio_split;
590 
591 #ifdef CONFIG_BLK_DEBUG_FS
592 	struct dentry		*debugfs_dir;
593 	struct dentry		*sched_debugfs_dir;
594 #endif
595 
596 	bool			mq_sysfs_init_done;
597 
598 	size_t			cmd_size;
599 	void			*rq_alloc_data;
600 
601 	struct work_struct	release_work;
602 
603 #define BLK_MAX_WRITE_HINTS	5
604 	u64			write_hints[BLK_MAX_WRITE_HINTS];
605 };
606 
607 #define QUEUE_FLAG_QUEUED	0	/* uses generic tag queueing */
608 #define QUEUE_FLAG_STOPPED	1	/* queue is stopped */
609 #define QUEUE_FLAG_DYING	2	/* queue being torn down */
610 #define QUEUE_FLAG_BYPASS	3	/* act as dumb FIFO queue */
611 #define QUEUE_FLAG_BIDI		4	/* queue supports bidi requests */
612 #define QUEUE_FLAG_NOMERGES     5	/* disable merge attempts */
613 #define QUEUE_FLAG_SAME_COMP	6	/* complete on same CPU-group */
614 #define QUEUE_FLAG_FAIL_IO	7	/* fake timeout */
615 #define QUEUE_FLAG_NONROT	9	/* non-rotational device (SSD) */
616 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
617 #define QUEUE_FLAG_IO_STAT     10	/* do IO stats */
618 #define QUEUE_FLAG_DISCARD     11	/* supports DISCARD */
619 #define QUEUE_FLAG_NOXMERGES   12	/* No extended merges */
620 #define QUEUE_FLAG_ADD_RANDOM  13	/* Contributes to random pool */
621 #define QUEUE_FLAG_SECERASE    14	/* supports secure erase */
622 #define QUEUE_FLAG_SAME_FORCE  15	/* force complete on same CPU */
623 #define QUEUE_FLAG_DEAD        16	/* queue tear-down finished */
624 #define QUEUE_FLAG_INIT_DONE   17	/* queue is initialized */
625 #define QUEUE_FLAG_NO_SG_MERGE 18	/* don't attempt to merge SG segments*/
626 #define QUEUE_FLAG_POLL	       19	/* IO polling enabled if set */
627 #define QUEUE_FLAG_WC	       20	/* Write back caching */
628 #define QUEUE_FLAG_FUA	       21	/* device supports FUA writes */
629 #define QUEUE_FLAG_FLUSH_NQ    22	/* flush not queueuable */
630 #define QUEUE_FLAG_DAX         23	/* device supports DAX */
631 #define QUEUE_FLAG_STATS       24	/* track rq completion times */
632 #define QUEUE_FLAG_POLL_STATS  25	/* collecting stats for hybrid polling */
633 #define QUEUE_FLAG_REGISTERED  26	/* queue has been registered to a disk */
634 #define QUEUE_FLAG_SCSI_PASSTHROUGH 27	/* queue supports SCSI commands */
635 #define QUEUE_FLAG_QUIESCED    28	/* queue has been quiesced */
636 #define QUEUE_FLAG_PREEMPT_ONLY	29	/* only process REQ_PREEMPT requests */
637 
638 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
639 				 (1 << QUEUE_FLAG_SAME_COMP)	|	\
640 				 (1 << QUEUE_FLAG_ADD_RANDOM))
641 
642 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
643 				 (1 << QUEUE_FLAG_SAME_COMP)	|	\
644 				 (1 << QUEUE_FLAG_POLL))
645 
646 /*
647  * @q->queue_lock is set while a queue is being initialized. Since we know
648  * that no other threads access the queue object before @q->queue_lock has
649  * been set, it is safe to manipulate queue flags without holding the
650  * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
651  * blk_init_allocated_queue().
652  */
653 static inline void queue_lockdep_assert_held(struct request_queue *q)
654 {
655 	if (q->queue_lock)
656 		lockdep_assert_held(q->queue_lock);
657 }
658 
659 static inline void queue_flag_set_unlocked(unsigned int flag,
660 					   struct request_queue *q)
661 {
662 	__set_bit(flag, &q->queue_flags);
663 }
664 
665 static inline int queue_flag_test_and_clear(unsigned int flag,
666 					    struct request_queue *q)
667 {
668 	queue_lockdep_assert_held(q);
669 
670 	if (test_bit(flag, &q->queue_flags)) {
671 		__clear_bit(flag, &q->queue_flags);
672 		return 1;
673 	}
674 
675 	return 0;
676 }
677 
678 static inline int queue_flag_test_and_set(unsigned int flag,
679 					  struct request_queue *q)
680 {
681 	queue_lockdep_assert_held(q);
682 
683 	if (!test_bit(flag, &q->queue_flags)) {
684 		__set_bit(flag, &q->queue_flags);
685 		return 0;
686 	}
687 
688 	return 1;
689 }
690 
691 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
692 {
693 	queue_lockdep_assert_held(q);
694 	__set_bit(flag, &q->queue_flags);
695 }
696 
697 static inline void queue_flag_clear_unlocked(unsigned int flag,
698 					     struct request_queue *q)
699 {
700 	__clear_bit(flag, &q->queue_flags);
701 }
702 
703 static inline int queue_in_flight(struct request_queue *q)
704 {
705 	return q->in_flight[0] + q->in_flight[1];
706 }
707 
708 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
709 {
710 	queue_lockdep_assert_held(q);
711 	__clear_bit(flag, &q->queue_flags);
712 }
713 
714 #define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
715 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
716 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
717 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
718 #define blk_queue_bypass(q)	test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
719 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
720 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
721 #define blk_queue_noxmerges(q)	\
722 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
723 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
724 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
725 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
726 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
727 #define blk_queue_secure_erase(q) \
728 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
729 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
730 #define blk_queue_scsi_passthrough(q)	\
731 	test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
732 
733 #define blk_noretry_request(rq) \
734 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
735 			     REQ_FAILFAST_DRIVER))
736 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
737 #define blk_queue_preempt_only(q)				\
738 	test_bit(QUEUE_FLAG_PREEMPT_ONLY, &(q)->queue_flags)
739 
740 extern int blk_set_preempt_only(struct request_queue *q);
741 extern void blk_clear_preempt_only(struct request_queue *q);
742 
743 static inline bool blk_account_rq(struct request *rq)
744 {
745 	return (rq->rq_flags & RQF_STARTED) && !blk_rq_is_passthrough(rq);
746 }
747 
748 #define blk_rq_cpu_valid(rq)	((rq)->cpu != -1)
749 #define blk_bidi_rq(rq)		((rq)->next_rq != NULL)
750 /* rq->queuelist of dequeued request must be list_empty() */
751 #define blk_queued_rq(rq)	(!list_empty(&(rq)->queuelist))
752 
753 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
754 
755 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
756 
757 /*
758  * Driver can handle struct request, if it either has an old style
759  * request_fn defined, or is blk-mq based.
760  */
761 static inline bool queue_is_rq_based(struct request_queue *q)
762 {
763 	return q->request_fn || q->mq_ops;
764 }
765 
766 static inline unsigned int blk_queue_cluster(struct request_queue *q)
767 {
768 	return q->limits.cluster;
769 }
770 
771 static inline enum blk_zoned_model
772 blk_queue_zoned_model(struct request_queue *q)
773 {
774 	return q->limits.zoned;
775 }
776 
777 static inline bool blk_queue_is_zoned(struct request_queue *q)
778 {
779 	switch (blk_queue_zoned_model(q)) {
780 	case BLK_ZONED_HA:
781 	case BLK_ZONED_HM:
782 		return true;
783 	default:
784 		return false;
785 	}
786 }
787 
788 static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
789 {
790 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
791 }
792 
793 static inline bool rq_is_sync(struct request *rq)
794 {
795 	return op_is_sync(rq->cmd_flags);
796 }
797 
798 static inline bool blk_rl_full(struct request_list *rl, bool sync)
799 {
800 	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
801 
802 	return rl->flags & flag;
803 }
804 
805 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
806 {
807 	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
808 
809 	rl->flags |= flag;
810 }
811 
812 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
813 {
814 	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
815 
816 	rl->flags &= ~flag;
817 }
818 
819 static inline bool rq_mergeable(struct request *rq)
820 {
821 	if (blk_rq_is_passthrough(rq))
822 		return false;
823 
824 	if (req_op(rq) == REQ_OP_FLUSH)
825 		return false;
826 
827 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
828 		return false;
829 
830 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
831 		return false;
832 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
833 		return false;
834 
835 	return true;
836 }
837 
838 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
839 {
840 	if (bio_page(a) == bio_page(b) &&
841 	    bio_offset(a) == bio_offset(b))
842 		return true;
843 
844 	return false;
845 }
846 
847 static inline unsigned int blk_queue_depth(struct request_queue *q)
848 {
849 	if (q->queue_depth)
850 		return q->queue_depth;
851 
852 	return q->nr_requests;
853 }
854 
855 /*
856  * q->prep_rq_fn return values
857  */
858 enum {
859 	BLKPREP_OK,		/* serve it */
860 	BLKPREP_KILL,		/* fatal error, kill, return -EIO */
861 	BLKPREP_DEFER,		/* leave on queue */
862 	BLKPREP_INVALID,	/* invalid command, kill, return -EREMOTEIO */
863 };
864 
865 extern unsigned long blk_max_low_pfn, blk_max_pfn;
866 
867 /*
868  * standard bounce addresses:
869  *
870  * BLK_BOUNCE_HIGH	: bounce all highmem pages
871  * BLK_BOUNCE_ANY	: don't bounce anything
872  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
873  */
874 
875 #if BITS_PER_LONG == 32
876 #define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
877 #else
878 #define BLK_BOUNCE_HIGH		-1ULL
879 #endif
880 #define BLK_BOUNCE_ANY		(-1ULL)
881 #define BLK_BOUNCE_ISA		(DMA_BIT_MASK(24))
882 
883 /*
884  * default timeout for SG_IO if none specified
885  */
886 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
887 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
888 
889 struct rq_map_data {
890 	struct page **pages;
891 	int page_order;
892 	int nr_entries;
893 	unsigned long offset;
894 	int null_mapped;
895 	int from_user;
896 };
897 
898 struct req_iterator {
899 	struct bvec_iter iter;
900 	struct bio *bio;
901 };
902 
903 /* This should not be used directly - use rq_for_each_segment */
904 #define for_each_bio(_bio)		\
905 	for (; _bio; _bio = _bio->bi_next)
906 #define __rq_for_each_bio(_bio, rq)	\
907 	if ((rq->bio))			\
908 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
909 
910 #define rq_for_each_segment(bvl, _rq, _iter)			\
911 	__rq_for_each_bio(_iter.bio, _rq)			\
912 		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
913 
914 #define rq_iter_last(bvec, _iter)				\
915 		(_iter.bio->bi_next == NULL &&			\
916 		 bio_iter_last(bvec, _iter.iter))
917 
918 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
919 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
920 #endif
921 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
922 extern void rq_flush_dcache_pages(struct request *rq);
923 #else
924 static inline void rq_flush_dcache_pages(struct request *rq)
925 {
926 }
927 #endif
928 
929 extern int blk_register_queue(struct gendisk *disk);
930 extern void blk_unregister_queue(struct gendisk *disk);
931 extern blk_qc_t generic_make_request(struct bio *bio);
932 extern blk_qc_t direct_make_request(struct bio *bio);
933 extern void blk_rq_init(struct request_queue *q, struct request *rq);
934 extern void blk_init_request_from_bio(struct request *req, struct bio *bio);
935 extern void blk_put_request(struct request *);
936 extern void __blk_put_request(struct request_queue *, struct request *);
937 extern struct request *blk_get_request_flags(struct request_queue *,
938 					     unsigned int op,
939 					     blk_mq_req_flags_t flags);
940 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
941 				       gfp_t gfp_mask);
942 extern void blk_requeue_request(struct request_queue *, struct request *);
943 extern int blk_lld_busy(struct request_queue *q);
944 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
945 			     struct bio_set *bs, gfp_t gfp_mask,
946 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
947 			     void *data);
948 extern void blk_rq_unprep_clone(struct request *rq);
949 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
950 				     struct request *rq);
951 extern int blk_rq_append_bio(struct request *rq, struct bio *bio);
952 extern void blk_delay_queue(struct request_queue *, unsigned long);
953 extern void blk_queue_split(struct request_queue *, struct bio **);
954 extern void blk_recount_segments(struct request_queue *, struct bio *);
955 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
956 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
957 			      unsigned int, void __user *);
958 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
959 			  unsigned int, void __user *);
960 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
961 			 struct scsi_ioctl_command __user *);
962 
963 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
964 extern void blk_queue_exit(struct request_queue *q);
965 extern void blk_start_queue(struct request_queue *q);
966 extern void blk_start_queue_async(struct request_queue *q);
967 extern void blk_stop_queue(struct request_queue *q);
968 extern void blk_sync_queue(struct request_queue *q);
969 extern void __blk_stop_queue(struct request_queue *q);
970 extern void __blk_run_queue(struct request_queue *q);
971 extern void __blk_run_queue_uncond(struct request_queue *q);
972 extern void blk_run_queue(struct request_queue *);
973 extern void blk_run_queue_async(struct request_queue *q);
974 extern int blk_rq_map_user(struct request_queue *, struct request *,
975 			   struct rq_map_data *, void __user *, unsigned long,
976 			   gfp_t);
977 extern int blk_rq_unmap_user(struct bio *);
978 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
979 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
980 			       struct rq_map_data *, const struct iov_iter *,
981 			       gfp_t);
982 extern void blk_execute_rq(struct request_queue *, struct gendisk *,
983 			  struct request *, int);
984 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
985 				  struct request *, int, rq_end_io_fn *);
986 
987 int blk_status_to_errno(blk_status_t status);
988 blk_status_t errno_to_blk_status(int errno);
989 
990 bool blk_poll(struct request_queue *q, blk_qc_t cookie);
991 
992 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
993 {
994 	return bdev->bd_disk->queue;	/* this is never NULL */
995 }
996 
997 /*
998  * blk_rq_pos()			: the current sector
999  * blk_rq_bytes()		: bytes left in the entire request
1000  * blk_rq_cur_bytes()		: bytes left in the current segment
1001  * blk_rq_err_bytes()		: bytes left till the next error boundary
1002  * blk_rq_sectors()		: sectors left in the entire request
1003  * blk_rq_cur_sectors()		: sectors left in the current segment
1004  */
1005 static inline sector_t blk_rq_pos(const struct request *rq)
1006 {
1007 	return rq->__sector;
1008 }
1009 
1010 static inline unsigned int blk_rq_bytes(const struct request *rq)
1011 {
1012 	return rq->__data_len;
1013 }
1014 
1015 static inline int blk_rq_cur_bytes(const struct request *rq)
1016 {
1017 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
1018 }
1019 
1020 extern unsigned int blk_rq_err_bytes(const struct request *rq);
1021 
1022 static inline unsigned int blk_rq_sectors(const struct request *rq)
1023 {
1024 	return blk_rq_bytes(rq) >> 9;
1025 }
1026 
1027 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
1028 {
1029 	return blk_rq_cur_bytes(rq) >> 9;
1030 }
1031 
1032 /*
1033  * Some commands like WRITE SAME have a payload or data transfer size which
1034  * is different from the size of the request.  Any driver that supports such
1035  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
1036  * calculate the data transfer size.
1037  */
1038 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
1039 {
1040 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1041 		return rq->special_vec.bv_len;
1042 	return blk_rq_bytes(rq);
1043 }
1044 
1045 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
1046 						     int op)
1047 {
1048 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
1049 		return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
1050 
1051 	if (unlikely(op == REQ_OP_WRITE_SAME))
1052 		return q->limits.max_write_same_sectors;
1053 
1054 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
1055 		return q->limits.max_write_zeroes_sectors;
1056 
1057 	return q->limits.max_sectors;
1058 }
1059 
1060 /*
1061  * Return maximum size of a request at given offset. Only valid for
1062  * file system requests.
1063  */
1064 static inline unsigned int blk_max_size_offset(struct request_queue *q,
1065 					       sector_t offset)
1066 {
1067 	if (!q->limits.chunk_sectors)
1068 		return q->limits.max_sectors;
1069 
1070 	return q->limits.chunk_sectors -
1071 			(offset & (q->limits.chunk_sectors - 1));
1072 }
1073 
1074 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
1075 						  sector_t offset)
1076 {
1077 	struct request_queue *q = rq->q;
1078 
1079 	if (blk_rq_is_passthrough(rq))
1080 		return q->limits.max_hw_sectors;
1081 
1082 	if (!q->limits.chunk_sectors ||
1083 	    req_op(rq) == REQ_OP_DISCARD ||
1084 	    req_op(rq) == REQ_OP_SECURE_ERASE)
1085 		return blk_queue_get_max_sectors(q, req_op(rq));
1086 
1087 	return min(blk_max_size_offset(q, offset),
1088 			blk_queue_get_max_sectors(q, req_op(rq)));
1089 }
1090 
1091 static inline unsigned int blk_rq_count_bios(struct request *rq)
1092 {
1093 	unsigned int nr_bios = 0;
1094 	struct bio *bio;
1095 
1096 	__rq_for_each_bio(bio, rq)
1097 		nr_bios++;
1098 
1099 	return nr_bios;
1100 }
1101 
1102 /*
1103  * Request issue related functions.
1104  */
1105 extern struct request *blk_peek_request(struct request_queue *q);
1106 extern void blk_start_request(struct request *rq);
1107 extern struct request *blk_fetch_request(struct request_queue *q);
1108 
1109 void blk_steal_bios(struct bio_list *list, struct request *rq);
1110 
1111 /*
1112  * Request completion related functions.
1113  *
1114  * blk_update_request() completes given number of bytes and updates
1115  * the request without completing it.
1116  *
1117  * blk_end_request() and friends.  __blk_end_request() must be called
1118  * with the request queue spinlock acquired.
1119  *
1120  * Several drivers define their own end_request and call
1121  * blk_end_request() for parts of the original function.
1122  * This prevents code duplication in drivers.
1123  */
1124 extern bool blk_update_request(struct request *rq, blk_status_t error,
1125 			       unsigned int nr_bytes);
1126 extern void blk_finish_request(struct request *rq, blk_status_t error);
1127 extern bool blk_end_request(struct request *rq, blk_status_t error,
1128 			    unsigned int nr_bytes);
1129 extern void blk_end_request_all(struct request *rq, blk_status_t error);
1130 extern bool __blk_end_request(struct request *rq, blk_status_t error,
1131 			      unsigned int nr_bytes);
1132 extern void __blk_end_request_all(struct request *rq, blk_status_t error);
1133 extern bool __blk_end_request_cur(struct request *rq, blk_status_t error);
1134 
1135 extern void blk_complete_request(struct request *);
1136 extern void __blk_complete_request(struct request *);
1137 extern void blk_abort_request(struct request *);
1138 extern void blk_unprep_request(struct request *);
1139 
1140 /*
1141  * Access functions for manipulating queue properties
1142  */
1143 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
1144 					spinlock_t *lock, int node_id);
1145 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
1146 extern int blk_init_allocated_queue(struct request_queue *);
1147 extern void blk_cleanup_queue(struct request_queue *);
1148 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1149 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1150 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1151 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1152 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1153 extern void blk_queue_max_discard_segments(struct request_queue *,
1154 		unsigned short);
1155 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1156 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1157 		unsigned int max_discard_sectors);
1158 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1159 		unsigned int max_write_same_sectors);
1160 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1161 		unsigned int max_write_same_sectors);
1162 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
1163 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1164 extern void blk_queue_alignment_offset(struct request_queue *q,
1165 				       unsigned int alignment);
1166 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1167 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1168 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1169 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1170 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1171 extern void blk_set_default_limits(struct queue_limits *lim);
1172 extern void blk_set_stacking_limits(struct queue_limits *lim);
1173 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1174 			    sector_t offset);
1175 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1176 			    sector_t offset);
1177 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1178 			      sector_t offset);
1179 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1180 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1181 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1182 extern int blk_queue_dma_drain(struct request_queue *q,
1183 			       dma_drain_needed_fn *dma_drain_needed,
1184 			       void *buf, unsigned int size);
1185 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1186 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1187 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1188 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1189 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
1190 extern void blk_queue_dma_alignment(struct request_queue *, int);
1191 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1192 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1193 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1194 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1195 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1196 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1197 
1198 /*
1199  * Number of physical segments as sent to the device.
1200  *
1201  * Normally this is the number of discontiguous data segments sent by the
1202  * submitter.  But for data-less command like discard we might have no
1203  * actual data segments submitted, but the driver might have to add it's
1204  * own special payload.  In that case we still return 1 here so that this
1205  * special payload will be mapped.
1206  */
1207 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1208 {
1209 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1210 		return 1;
1211 	return rq->nr_phys_segments;
1212 }
1213 
1214 /*
1215  * Number of discard segments (or ranges) the driver needs to fill in.
1216  * Each discard bio merged into a request is counted as one segment.
1217  */
1218 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1219 {
1220 	return max_t(unsigned short, rq->nr_phys_segments, 1);
1221 }
1222 
1223 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1224 extern void blk_dump_rq_flags(struct request *, char *);
1225 extern long nr_blockdev_pages(void);
1226 
1227 bool __must_check blk_get_queue(struct request_queue *);
1228 struct request_queue *blk_alloc_queue(gfp_t);
1229 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1230 extern void blk_put_queue(struct request_queue *);
1231 extern void blk_set_queue_dying(struct request_queue *);
1232 
1233 /*
1234  * block layer runtime pm functions
1235  */
1236 #ifdef CONFIG_PM
1237 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1238 extern int blk_pre_runtime_suspend(struct request_queue *q);
1239 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1240 extern void blk_pre_runtime_resume(struct request_queue *q);
1241 extern void blk_post_runtime_resume(struct request_queue *q, int err);
1242 extern void blk_set_runtime_active(struct request_queue *q);
1243 #else
1244 static inline void blk_pm_runtime_init(struct request_queue *q,
1245 	struct device *dev) {}
1246 static inline int blk_pre_runtime_suspend(struct request_queue *q)
1247 {
1248 	return -ENOSYS;
1249 }
1250 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1251 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1252 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1253 static inline void blk_set_runtime_active(struct request_queue *q) {}
1254 #endif
1255 
1256 /*
1257  * blk_plug permits building a queue of related requests by holding the I/O
1258  * fragments for a short period. This allows merging of sequential requests
1259  * into single larger request. As the requests are moved from a per-task list to
1260  * the device's request_queue in a batch, this results in improved scalability
1261  * as the lock contention for request_queue lock is reduced.
1262  *
1263  * It is ok not to disable preemption when adding the request to the plug list
1264  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1265  * the plug list when the task sleeps by itself. For details, please see
1266  * schedule() where blk_schedule_flush_plug() is called.
1267  */
1268 struct blk_plug {
1269 	struct list_head list; /* requests */
1270 	struct list_head mq_list; /* blk-mq requests */
1271 	struct list_head cb_list; /* md requires an unplug callback */
1272 };
1273 #define BLK_MAX_REQUEST_COUNT 16
1274 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1275 
1276 struct blk_plug_cb;
1277 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1278 struct blk_plug_cb {
1279 	struct list_head list;
1280 	blk_plug_cb_fn callback;
1281 	void *data;
1282 };
1283 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1284 					     void *data, int size);
1285 extern void blk_start_plug(struct blk_plug *);
1286 extern void blk_finish_plug(struct blk_plug *);
1287 extern void blk_flush_plug_list(struct blk_plug *, bool);
1288 
1289 static inline void blk_flush_plug(struct task_struct *tsk)
1290 {
1291 	struct blk_plug *plug = tsk->plug;
1292 
1293 	if (plug)
1294 		blk_flush_plug_list(plug, false);
1295 }
1296 
1297 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1298 {
1299 	struct blk_plug *plug = tsk->plug;
1300 
1301 	if (plug)
1302 		blk_flush_plug_list(plug, true);
1303 }
1304 
1305 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1306 {
1307 	struct blk_plug *plug = tsk->plug;
1308 
1309 	return plug &&
1310 		(!list_empty(&plug->list) ||
1311 		 !list_empty(&plug->mq_list) ||
1312 		 !list_empty(&plug->cb_list));
1313 }
1314 
1315 /*
1316  * tag stuff
1317  */
1318 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1319 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1320 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1321 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
1322 extern void blk_queue_free_tags(struct request_queue *);
1323 extern int blk_queue_resize_tags(struct request_queue *, int);
1324 extern void blk_queue_invalidate_tags(struct request_queue *);
1325 extern struct blk_queue_tag *blk_init_tags(int, int);
1326 extern void blk_free_tags(struct blk_queue_tag *);
1327 
1328 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1329 						int tag)
1330 {
1331 	if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1332 		return NULL;
1333 	return bqt->tag_index[tag];
1334 }
1335 
1336 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1337 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1338 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1339 
1340 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
1341 
1342 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1343 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1344 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1345 		sector_t nr_sects, gfp_t gfp_mask, int flags,
1346 		struct bio **biop);
1347 
1348 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
1349 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
1350 
1351 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1352 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1353 		unsigned flags);
1354 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1355 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1356 
1357 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1358 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1359 {
1360 	return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1361 				    nr_blocks << (sb->s_blocksize_bits - 9),
1362 				    gfp_mask, flags);
1363 }
1364 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1365 		sector_t nr_blocks, gfp_t gfp_mask)
1366 {
1367 	return blkdev_issue_zeroout(sb->s_bdev,
1368 				    block << (sb->s_blocksize_bits - 9),
1369 				    nr_blocks << (sb->s_blocksize_bits - 9),
1370 				    gfp_mask, 0);
1371 }
1372 
1373 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1374 
1375 enum blk_default_limits {
1376 	BLK_MAX_SEGMENTS	= 128,
1377 	BLK_SAFE_MAX_SECTORS	= 255,
1378 	BLK_DEF_MAX_SECTORS	= 2560,
1379 	BLK_MAX_SEGMENT_SIZE	= 65536,
1380 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
1381 };
1382 
1383 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1384 
1385 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1386 {
1387 	return q->limits.seg_boundary_mask;
1388 }
1389 
1390 static inline unsigned long queue_virt_boundary(struct request_queue *q)
1391 {
1392 	return q->limits.virt_boundary_mask;
1393 }
1394 
1395 static inline unsigned int queue_max_sectors(struct request_queue *q)
1396 {
1397 	return q->limits.max_sectors;
1398 }
1399 
1400 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1401 {
1402 	return q->limits.max_hw_sectors;
1403 }
1404 
1405 static inline unsigned short queue_max_segments(struct request_queue *q)
1406 {
1407 	return q->limits.max_segments;
1408 }
1409 
1410 static inline unsigned short queue_max_discard_segments(struct request_queue *q)
1411 {
1412 	return q->limits.max_discard_segments;
1413 }
1414 
1415 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1416 {
1417 	return q->limits.max_segment_size;
1418 }
1419 
1420 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1421 {
1422 	int retval = 512;
1423 
1424 	if (q && q->limits.logical_block_size)
1425 		retval = q->limits.logical_block_size;
1426 
1427 	return retval;
1428 }
1429 
1430 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1431 {
1432 	return queue_logical_block_size(bdev_get_queue(bdev));
1433 }
1434 
1435 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1436 {
1437 	return q->limits.physical_block_size;
1438 }
1439 
1440 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1441 {
1442 	return queue_physical_block_size(bdev_get_queue(bdev));
1443 }
1444 
1445 static inline unsigned int queue_io_min(struct request_queue *q)
1446 {
1447 	return q->limits.io_min;
1448 }
1449 
1450 static inline int bdev_io_min(struct block_device *bdev)
1451 {
1452 	return queue_io_min(bdev_get_queue(bdev));
1453 }
1454 
1455 static inline unsigned int queue_io_opt(struct request_queue *q)
1456 {
1457 	return q->limits.io_opt;
1458 }
1459 
1460 static inline int bdev_io_opt(struct block_device *bdev)
1461 {
1462 	return queue_io_opt(bdev_get_queue(bdev));
1463 }
1464 
1465 static inline int queue_alignment_offset(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 >> 9) << 9;
1477 
1478 	return (granularity + lim->alignment_offset - alignment) % granularity;
1479 }
1480 
1481 static inline int bdev_alignment_offset(struct block_device *bdev)
1482 {
1483 	struct request_queue *q = bdev_get_queue(bdev);
1484 
1485 	if (q->limits.misaligned)
1486 		return -1;
1487 
1488 	if (bdev != bdev->bd_contains)
1489 		return bdev->bd_part->alignment_offset;
1490 
1491 	return q->limits.alignment_offset;
1492 }
1493 
1494 static inline int queue_discard_alignment(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 >> 9;
1511 	granularity = lim->discard_granularity >> 9;
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 << 9;
1523 }
1524 
1525 static inline int bdev_discard_alignment(struct block_device *bdev)
1526 {
1527 	struct request_queue *q = bdev_get_queue(bdev);
1528 
1529 	if (bdev != bdev->bd_contains)
1530 		return bdev->bd_part->discard_alignment;
1531 
1532 	return q->limits.discard_alignment;
1533 }
1534 
1535 static inline unsigned int bdev_write_same(struct block_device *bdev)
1536 {
1537 	struct request_queue *q = bdev_get_queue(bdev);
1538 
1539 	if (q)
1540 		return q->limits.max_write_same_sectors;
1541 
1542 	return 0;
1543 }
1544 
1545 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1546 {
1547 	struct request_queue *q = bdev_get_queue(bdev);
1548 
1549 	if (q)
1550 		return q->limits.max_write_zeroes_sectors;
1551 
1552 	return 0;
1553 }
1554 
1555 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1556 {
1557 	struct request_queue *q = bdev_get_queue(bdev);
1558 
1559 	if (q)
1560 		return blk_queue_zoned_model(q);
1561 
1562 	return BLK_ZONED_NONE;
1563 }
1564 
1565 static inline bool bdev_is_zoned(struct block_device *bdev)
1566 {
1567 	struct request_queue *q = bdev_get_queue(bdev);
1568 
1569 	if (q)
1570 		return blk_queue_is_zoned(q);
1571 
1572 	return false;
1573 }
1574 
1575 static inline unsigned int bdev_zone_sectors(struct block_device *bdev)
1576 {
1577 	struct request_queue *q = bdev_get_queue(bdev);
1578 
1579 	if (q)
1580 		return blk_queue_zone_sectors(q);
1581 
1582 	return 0;
1583 }
1584 
1585 static inline int queue_dma_alignment(struct request_queue *q)
1586 {
1587 	return q ? q->dma_alignment : 511;
1588 }
1589 
1590 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1591 				 unsigned int len)
1592 {
1593 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1594 	return !(addr & alignment) && !(len & alignment);
1595 }
1596 
1597 /* assumes size > 256 */
1598 static inline unsigned int blksize_bits(unsigned int size)
1599 {
1600 	unsigned int bits = 8;
1601 	do {
1602 		bits++;
1603 		size >>= 1;
1604 	} while (size > 256);
1605 	return bits;
1606 }
1607 
1608 static inline unsigned int block_size(struct block_device *bdev)
1609 {
1610 	return bdev->bd_block_size;
1611 }
1612 
1613 static inline bool queue_flush_queueable(struct request_queue *q)
1614 {
1615 	return !test_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags);
1616 }
1617 
1618 typedef struct {struct page *v;} Sector;
1619 
1620 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1621 
1622 static inline void put_dev_sector(Sector p)
1623 {
1624 	put_page(p.v);
1625 }
1626 
1627 static inline bool __bvec_gap_to_prev(struct request_queue *q,
1628 				struct bio_vec *bprv, unsigned int offset)
1629 {
1630 	return offset ||
1631 		((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
1632 }
1633 
1634 /*
1635  * Check if adding a bio_vec after bprv with offset would create a gap in
1636  * the SG list. Most drivers don't care about this, but some do.
1637  */
1638 static inline bool bvec_gap_to_prev(struct request_queue *q,
1639 				struct bio_vec *bprv, unsigned int offset)
1640 {
1641 	if (!queue_virt_boundary(q))
1642 		return false;
1643 	return __bvec_gap_to_prev(q, bprv, offset);
1644 }
1645 
1646 /*
1647  * Check if the two bvecs from two bios can be merged to one segment.
1648  * If yes, no need to check gap between the two bios since the 1st bio
1649  * and the 1st bvec in the 2nd bio can be handled in one segment.
1650  */
1651 static inline bool bios_segs_mergeable(struct request_queue *q,
1652 		struct bio *prev, struct bio_vec *prev_last_bv,
1653 		struct bio_vec *next_first_bv)
1654 {
1655 	if (!BIOVEC_PHYS_MERGEABLE(prev_last_bv, next_first_bv))
1656 		return false;
1657 	if (!BIOVEC_SEG_BOUNDARY(q, prev_last_bv, next_first_bv))
1658 		return false;
1659 	if (prev->bi_seg_back_size + next_first_bv->bv_len >
1660 			queue_max_segment_size(q))
1661 		return false;
1662 	return true;
1663 }
1664 
1665 static inline bool bio_will_gap(struct request_queue *q,
1666 				struct request *prev_rq,
1667 				struct bio *prev,
1668 				struct bio *next)
1669 {
1670 	if (bio_has_data(prev) && queue_virt_boundary(q)) {
1671 		struct bio_vec pb, nb;
1672 
1673 		/*
1674 		 * don't merge if the 1st bio starts with non-zero
1675 		 * offset, otherwise it is quite difficult to respect
1676 		 * sg gap limit. We work hard to merge a huge number of small
1677 		 * single bios in case of mkfs.
1678 		 */
1679 		if (prev_rq)
1680 			bio_get_first_bvec(prev_rq->bio, &pb);
1681 		else
1682 			bio_get_first_bvec(prev, &pb);
1683 		if (pb.bv_offset)
1684 			return true;
1685 
1686 		/*
1687 		 * We don't need to worry about the situation that the
1688 		 * merged segment ends in unaligned virt boundary:
1689 		 *
1690 		 * - if 'pb' ends aligned, the merged segment ends aligned
1691 		 * - if 'pb' ends unaligned, the next bio must include
1692 		 *   one single bvec of 'nb', otherwise the 'nb' can't
1693 		 *   merge with 'pb'
1694 		 */
1695 		bio_get_last_bvec(prev, &pb);
1696 		bio_get_first_bvec(next, &nb);
1697 
1698 		if (!bios_segs_mergeable(q, prev, &pb, &nb))
1699 			return __bvec_gap_to_prev(q, &pb, nb.bv_offset);
1700 	}
1701 
1702 	return false;
1703 }
1704 
1705 static inline bool req_gap_back_merge(struct request *req, struct bio *bio)
1706 {
1707 	return bio_will_gap(req->q, req, req->biotail, bio);
1708 }
1709 
1710 static inline bool req_gap_front_merge(struct request *req, struct bio *bio)
1711 {
1712 	return bio_will_gap(req->q, NULL, bio, req->bio);
1713 }
1714 
1715 int kblockd_schedule_work(struct work_struct *work);
1716 int kblockd_schedule_work_on(int cpu, struct work_struct *work);
1717 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
1718 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1719 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1720 
1721 #ifdef CONFIG_BLK_CGROUP
1722 /*
1723  * This should not be using sched_clock(). A real patch is in progress
1724  * to fix this up, until that is in place we need to disable preemption
1725  * around sched_clock() in this function and set_io_start_time_ns().
1726  */
1727 static inline void set_start_time_ns(struct request *req)
1728 {
1729 	preempt_disable();
1730 	req->start_time_ns = sched_clock();
1731 	preempt_enable();
1732 }
1733 
1734 static inline void set_io_start_time_ns(struct request *req)
1735 {
1736 	preempt_disable();
1737 	req->io_start_time_ns = sched_clock();
1738 	preempt_enable();
1739 }
1740 
1741 static inline uint64_t rq_start_time_ns(struct request *req)
1742 {
1743         return req->start_time_ns;
1744 }
1745 
1746 static inline uint64_t rq_io_start_time_ns(struct request *req)
1747 {
1748         return req->io_start_time_ns;
1749 }
1750 #else
1751 static inline void set_start_time_ns(struct request *req) {}
1752 static inline void set_io_start_time_ns(struct request *req) {}
1753 static inline uint64_t rq_start_time_ns(struct request *req)
1754 {
1755 	return 0;
1756 }
1757 static inline uint64_t rq_io_start_time_ns(struct request *req)
1758 {
1759 	return 0;
1760 }
1761 #endif
1762 
1763 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1764 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1765 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1766 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1767 
1768 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1769 
1770 enum blk_integrity_flags {
1771 	BLK_INTEGRITY_VERIFY		= 1 << 0,
1772 	BLK_INTEGRITY_GENERATE		= 1 << 1,
1773 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
1774 	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
1775 };
1776 
1777 struct blk_integrity_iter {
1778 	void			*prot_buf;
1779 	void			*data_buf;
1780 	sector_t		seed;
1781 	unsigned int		data_size;
1782 	unsigned short		interval;
1783 	const char		*disk_name;
1784 };
1785 
1786 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1787 
1788 struct blk_integrity_profile {
1789 	integrity_processing_fn		*generate_fn;
1790 	integrity_processing_fn		*verify_fn;
1791 	const char			*name;
1792 };
1793 
1794 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1795 extern void blk_integrity_unregister(struct gendisk *);
1796 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1797 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1798 				   struct scatterlist *);
1799 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1800 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1801 				   struct request *);
1802 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1803 				    struct bio *);
1804 
1805 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1806 {
1807 	struct blk_integrity *bi = &disk->queue->integrity;
1808 
1809 	if (!bi->profile)
1810 		return NULL;
1811 
1812 	return bi;
1813 }
1814 
1815 static inline
1816 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1817 {
1818 	return blk_get_integrity(bdev->bd_disk);
1819 }
1820 
1821 static inline bool blk_integrity_rq(struct request *rq)
1822 {
1823 	return rq->cmd_flags & REQ_INTEGRITY;
1824 }
1825 
1826 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1827 						    unsigned int segs)
1828 {
1829 	q->limits.max_integrity_segments = segs;
1830 }
1831 
1832 static inline unsigned short
1833 queue_max_integrity_segments(struct request_queue *q)
1834 {
1835 	return q->limits.max_integrity_segments;
1836 }
1837 
1838 static inline bool integrity_req_gap_back_merge(struct request *req,
1839 						struct bio *next)
1840 {
1841 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
1842 	struct bio_integrity_payload *bip_next = bio_integrity(next);
1843 
1844 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
1845 				bip_next->bip_vec[0].bv_offset);
1846 }
1847 
1848 static inline bool integrity_req_gap_front_merge(struct request *req,
1849 						 struct bio *bio)
1850 {
1851 	struct bio_integrity_payload *bip = bio_integrity(bio);
1852 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
1853 
1854 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
1855 				bip_next->bip_vec[0].bv_offset);
1856 }
1857 
1858 #else /* CONFIG_BLK_DEV_INTEGRITY */
1859 
1860 struct bio;
1861 struct block_device;
1862 struct gendisk;
1863 struct blk_integrity;
1864 
1865 static inline int blk_integrity_rq(struct request *rq)
1866 {
1867 	return 0;
1868 }
1869 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1870 					    struct bio *b)
1871 {
1872 	return 0;
1873 }
1874 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1875 					  struct bio *b,
1876 					  struct scatterlist *s)
1877 {
1878 	return 0;
1879 }
1880 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1881 {
1882 	return NULL;
1883 }
1884 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1885 {
1886 	return NULL;
1887 }
1888 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1889 {
1890 	return 0;
1891 }
1892 static inline void blk_integrity_register(struct gendisk *d,
1893 					 struct blk_integrity *b)
1894 {
1895 }
1896 static inline void blk_integrity_unregister(struct gendisk *d)
1897 {
1898 }
1899 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1900 						    unsigned int segs)
1901 {
1902 }
1903 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1904 {
1905 	return 0;
1906 }
1907 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1908 					  struct request *r1,
1909 					  struct request *r2)
1910 {
1911 	return true;
1912 }
1913 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1914 					   struct request *r,
1915 					   struct bio *b)
1916 {
1917 	return true;
1918 }
1919 
1920 static inline bool integrity_req_gap_back_merge(struct request *req,
1921 						struct bio *next)
1922 {
1923 	return false;
1924 }
1925 static inline bool integrity_req_gap_front_merge(struct request *req,
1926 						 struct bio *bio)
1927 {
1928 	return false;
1929 }
1930 
1931 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1932 
1933 struct block_device_operations {
1934 	int (*open) (struct block_device *, fmode_t);
1935 	void (*release) (struct gendisk *, fmode_t);
1936 	int (*rw_page)(struct block_device *, sector_t, struct page *, bool);
1937 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1938 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1939 	unsigned int (*check_events) (struct gendisk *disk,
1940 				      unsigned int clearing);
1941 	/* ->media_changed() is DEPRECATED, use ->check_events() instead */
1942 	int (*media_changed) (struct gendisk *);
1943 	void (*unlock_native_capacity) (struct gendisk *);
1944 	int (*revalidate_disk) (struct gendisk *);
1945 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1946 	/* this callback is with swap_lock and sometimes page table lock held */
1947 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1948 	struct module *owner;
1949 	const struct pr_ops *pr_ops;
1950 };
1951 
1952 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1953 				 unsigned long);
1954 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1955 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1956 						struct writeback_control *);
1957 #else /* CONFIG_BLOCK */
1958 
1959 struct block_device;
1960 
1961 /*
1962  * stubs for when the block layer is configured out
1963  */
1964 #define buffer_heads_over_limit 0
1965 
1966 static inline long nr_blockdev_pages(void)
1967 {
1968 	return 0;
1969 }
1970 
1971 struct blk_plug {
1972 };
1973 
1974 static inline void blk_start_plug(struct blk_plug *plug)
1975 {
1976 }
1977 
1978 static inline void blk_finish_plug(struct blk_plug *plug)
1979 {
1980 }
1981 
1982 static inline void blk_flush_plug(struct task_struct *task)
1983 {
1984 }
1985 
1986 static inline void blk_schedule_flush_plug(struct task_struct *task)
1987 {
1988 }
1989 
1990 
1991 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1992 {
1993 	return false;
1994 }
1995 
1996 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1997 				     sector_t *error_sector)
1998 {
1999 	return 0;
2000 }
2001 
2002 #endif /* CONFIG_BLOCK */
2003 
2004 #endif
2005