xref: /linux-6.15/include/linux/blkdev.h (revision 4745dc8a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BLKDEV_H
3 #define _LINUX_BLKDEV_H
4 
5 #include <linux/sched.h>
6 #include <linux/sched/clock.h>
7 
8 #ifdef CONFIG_BLOCK
9 
10 #include <linux/major.h>
11 #include <linux/genhd.h>
12 #include <linux/list.h>
13 #include <linux/llist.h>
14 #include <linux/timer.h>
15 #include <linux/workqueue.h>
16 #include <linux/pagemap.h>
17 #include <linux/backing-dev-defs.h>
18 #include <linux/wait.h>
19 #include <linux/mempool.h>
20 #include <linux/pfn.h>
21 #include <linux/bio.h>
22 #include <linux/stringify.h>
23 #include <linux/gfp.h>
24 #include <linux/bsg.h>
25 #include <linux/smp.h>
26 #include <linux/rcupdate.h>
27 #include <linux/percpu-refcount.h>
28 #include <linux/scatterlist.h>
29 #include <linux/blkzoned.h>
30 
31 struct module;
32 struct scsi_ioctl_command;
33 
34 struct request_queue;
35 struct elevator_queue;
36 struct blk_trace;
37 struct request;
38 struct sg_io_hdr;
39 struct bsg_job;
40 struct blkcg_gq;
41 struct blk_flush_queue;
42 struct pr_ops;
43 struct rq_qos;
44 struct blk_queue_stats;
45 struct blk_stat_callback;
46 
47 #define BLKDEV_MIN_RQ	4
48 #define BLKDEV_MAX_RQ	128	/* Default maximum */
49 
50 /* Must be consistent with blk_mq_poll_stats_bkt() */
51 #define BLK_MQ_POLL_STATS_BKTS 16
52 
53 /* Doing classic polling */
54 #define BLK_MQ_POLL_CLASSIC -1
55 
56 /*
57  * Maximum number of blkcg policies allowed to be registered concurrently.
58  * Defined here to simplify include dependency.
59  */
60 #define BLKCG_MAX_POLS		5
61 
62 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
63 
64 /*
65  * request flags */
66 typedef __u32 __bitwise req_flags_t;
67 
68 /* elevator knows about this request */
69 #define RQF_SORTED		((__force req_flags_t)(1 << 0))
70 /* drive already may have started this one */
71 #define RQF_STARTED		((__force req_flags_t)(1 << 1))
72 /* may not be passed by ioscheduler */
73 #define RQF_SOFTBARRIER		((__force req_flags_t)(1 << 3))
74 /* request for flush sequence */
75 #define RQF_FLUSH_SEQ		((__force req_flags_t)(1 << 4))
76 /* merge of different types, fail separately */
77 #define RQF_MIXED_MERGE		((__force req_flags_t)(1 << 5))
78 /* track inflight for MQ */
79 #define RQF_MQ_INFLIGHT		((__force req_flags_t)(1 << 6))
80 /* don't call prep for this one */
81 #define RQF_DONTPREP		((__force req_flags_t)(1 << 7))
82 /* set for "ide_preempt" requests and also for requests for which the SCSI
83    "quiesce" state must be ignored. */
84 #define RQF_PREEMPT		((__force req_flags_t)(1 << 8))
85 /* contains copies of user pages */
86 #define RQF_COPY_USER		((__force req_flags_t)(1 << 9))
87 /* vaguely specified driver internal error.  Ignored by the block layer */
88 #define RQF_FAILED		((__force req_flags_t)(1 << 10))
89 /* don't warn about errors */
90 #define RQF_QUIET		((__force req_flags_t)(1 << 11))
91 /* elevator private data attached */
92 #define RQF_ELVPRIV		((__force req_flags_t)(1 << 12))
93 /* account into disk and partition IO statistics */
94 #define RQF_IO_STAT		((__force req_flags_t)(1 << 13))
95 /* request came from our alloc pool */
96 #define RQF_ALLOCED		((__force req_flags_t)(1 << 14))
97 /* runtime pm request */
98 #define RQF_PM			((__force req_flags_t)(1 << 15))
99 /* on IO scheduler merge hash */
100 #define RQF_HASHED		((__force req_flags_t)(1 << 16))
101 /* track IO completion time */
102 #define RQF_STATS		((__force req_flags_t)(1 << 17))
103 /* Look at ->special_vec for the actual data payload instead of the
104    bio chain. */
105 #define RQF_SPECIAL_PAYLOAD	((__force req_flags_t)(1 << 18))
106 /* The per-zone write lock is held for this request */
107 #define RQF_ZONE_WRITE_LOCKED	((__force req_flags_t)(1 << 19))
108 /* already slept for hybrid poll */
109 #define RQF_MQ_POLL_SLEPT	((__force req_flags_t)(1 << 20))
110 /* ->timeout has been called, don't expire again */
111 #define RQF_TIMED_OUT		((__force req_flags_t)(1 << 21))
112 
113 /* flags that prevent us from merging requests: */
114 #define RQF_NOMERGE_FLAGS \
115 	(RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
116 
117 /*
118  * Request state for blk-mq.
119  */
120 enum mq_rq_state {
121 	MQ_RQ_IDLE		= 0,
122 	MQ_RQ_IN_FLIGHT		= 1,
123 	MQ_RQ_COMPLETE		= 2,
124 };
125 
126 /*
127  * Try to put the fields that are referenced together in the same cacheline.
128  *
129  * If you modify this structure, make sure to update blk_rq_init() and
130  * especially blk_mq_rq_ctx_init() to take care of the added fields.
131  */
132 struct request {
133 	struct request_queue *q;
134 	struct blk_mq_ctx *mq_ctx;
135 	struct blk_mq_hw_ctx *mq_hctx;
136 
137 	unsigned int cmd_flags;		/* op and common flags */
138 	req_flags_t rq_flags;
139 
140 	int tag;
141 	int internal_tag;
142 
143 	/* the following two fields are internal, NEVER access directly */
144 	unsigned int __data_len;	/* total data len */
145 	sector_t __sector;		/* sector cursor */
146 
147 	struct bio *bio;
148 	struct bio *biotail;
149 
150 	struct list_head queuelist;
151 
152 	/*
153 	 * The hash is used inside the scheduler, and killed once the
154 	 * request reaches the dispatch list. The ipi_list is only used
155 	 * to queue the request for softirq completion, which is long
156 	 * after the request has been unhashed (and even removed from
157 	 * the dispatch list).
158 	 */
159 	union {
160 		struct hlist_node hash;	/* merge hash */
161 		struct list_head ipi_list;
162 	};
163 
164 	/*
165 	 * The rb_node is only used inside the io scheduler, requests
166 	 * are pruned when moved to the dispatch queue. So let the
167 	 * completion_data share space with the rb_node.
168 	 */
169 	union {
170 		struct rb_node rb_node;	/* sort/lookup */
171 		struct bio_vec special_vec;
172 		void *completion_data;
173 		int error_count; /* for legacy drivers, don't use */
174 	};
175 
176 	/*
177 	 * Three pointers are available for the IO schedulers, if they need
178 	 * more they have to dynamically allocate it.  Flush requests are
179 	 * never put on the IO scheduler. So let the flush fields share
180 	 * space with the elevator data.
181 	 */
182 	union {
183 		struct {
184 			struct io_cq		*icq;
185 			void			*priv[2];
186 		} elv;
187 
188 		struct {
189 			unsigned int		seq;
190 			struct list_head	list;
191 			rq_end_io_fn		*saved_end_io;
192 		} flush;
193 	};
194 
195 	struct gendisk *rq_disk;
196 	struct hd_struct *part;
197 	/* Time that I/O was submitted to the kernel. */
198 	u64 start_time_ns;
199 	/* Time that I/O was submitted to the device. */
200 	u64 io_start_time_ns;
201 
202 #ifdef CONFIG_BLK_WBT
203 	unsigned short wbt_flags;
204 #endif
205 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
206 	unsigned short throtl_size;
207 #endif
208 
209 	/*
210 	 * Number of scatter-gather DMA addr+len pairs after
211 	 * physical address coalescing is performed.
212 	 */
213 	unsigned short nr_phys_segments;
214 
215 #if defined(CONFIG_BLK_DEV_INTEGRITY)
216 	unsigned short nr_integrity_segments;
217 #endif
218 
219 	unsigned short write_hint;
220 	unsigned short ioprio;
221 
222 	unsigned int extra_len;	/* length of alignment and padding */
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_scsi(unsigned int op)
243 {
244 	return op == REQ_OP_SCSI_IN || op == REQ_OP_SCSI_OUT;
245 }
246 
247 static inline bool blk_op_is_private(unsigned int op)
248 {
249 	return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
250 }
251 
252 static inline bool blk_rq_is_scsi(struct request *rq)
253 {
254 	return blk_op_is_scsi(req_op(rq));
255 }
256 
257 static inline bool blk_rq_is_private(struct request *rq)
258 {
259 	return blk_op_is_private(req_op(rq));
260 }
261 
262 static inline bool blk_rq_is_passthrough(struct request *rq)
263 {
264 	return blk_rq_is_scsi(rq) || blk_rq_is_private(rq);
265 }
266 
267 static inline bool bio_is_passthrough(struct bio *bio)
268 {
269 	unsigned op = bio_op(bio);
270 
271 	return blk_op_is_scsi(op) || blk_op_is_private(op);
272 }
273 
274 static inline unsigned short req_get_ioprio(struct request *req)
275 {
276 	return req->ioprio;
277 }
278 
279 #include <linux/elevator.h>
280 
281 struct blk_queue_ctx;
282 
283 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
284 
285 struct bio_vec;
286 typedef int (dma_drain_needed_fn)(struct request *);
287 
288 enum blk_eh_timer_return {
289 	BLK_EH_DONE,		/* drivers has completed the command */
290 	BLK_EH_RESET_TIMER,	/* reset timer and try again */
291 };
292 
293 enum blk_queue_state {
294 	Queue_down,
295 	Queue_up,
296 };
297 
298 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
299 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
300 
301 #define BLK_SCSI_MAX_CMDS	(256)
302 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
303 
304 /*
305  * Zoned block device models (zoned limit).
306  */
307 enum blk_zoned_model {
308 	BLK_ZONED_NONE,	/* Regular block device */
309 	BLK_ZONED_HA,	/* Host-aware zoned block device */
310 	BLK_ZONED_HM,	/* Host-managed zoned block device */
311 };
312 
313 struct queue_limits {
314 	unsigned long		bounce_pfn;
315 	unsigned long		seg_boundary_mask;
316 	unsigned long		virt_boundary_mask;
317 
318 	unsigned int		max_hw_sectors;
319 	unsigned int		max_dev_sectors;
320 	unsigned int		chunk_sectors;
321 	unsigned int		max_sectors;
322 	unsigned int		max_segment_size;
323 	unsigned int		physical_block_size;
324 	unsigned int		alignment_offset;
325 	unsigned int		io_min;
326 	unsigned int		io_opt;
327 	unsigned int		max_discard_sectors;
328 	unsigned int		max_hw_discard_sectors;
329 	unsigned int		max_write_same_sectors;
330 	unsigned int		max_write_zeroes_sectors;
331 	unsigned int		discard_granularity;
332 	unsigned int		discard_alignment;
333 
334 	unsigned short		logical_block_size;
335 	unsigned short		max_segments;
336 	unsigned short		max_integrity_segments;
337 	unsigned short		max_discard_segments;
338 
339 	unsigned char		misaligned;
340 	unsigned char		discard_misaligned;
341 	unsigned char		raid_partial_stripes_expensive;
342 	enum blk_zoned_model	zoned;
343 };
344 
345 #ifdef CONFIG_BLK_DEV_ZONED
346 
347 extern unsigned int blkdev_nr_zones(struct block_device *bdev);
348 extern int blkdev_report_zones(struct block_device *bdev,
349 			       sector_t sector, struct blk_zone *zones,
350 			       unsigned int *nr_zones, gfp_t gfp_mask);
351 extern int blkdev_reset_zones(struct block_device *bdev, sector_t sectors,
352 			      sector_t nr_sectors, gfp_t gfp_mask);
353 extern int blk_revalidate_disk_zones(struct gendisk *disk);
354 
355 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
356 				     unsigned int cmd, unsigned long arg);
357 extern int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
358 				    unsigned int cmd, unsigned long arg);
359 
360 #else /* CONFIG_BLK_DEV_ZONED */
361 
362 static inline unsigned int blkdev_nr_zones(struct block_device *bdev)
363 {
364 	return 0;
365 }
366 
367 static inline int blk_revalidate_disk_zones(struct gendisk *disk)
368 {
369 	return 0;
370 }
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 
396 	struct blk_queue_stats	*stats;
397 	struct rq_qos		*rq_qos;
398 
399 	make_request_fn		*make_request_fn;
400 	dma_drain_needed_fn	*dma_drain_needed;
401 
402 	const struct blk_mq_ops	*mq_ops;
403 
404 	/* sw queues */
405 	struct blk_mq_ctx __percpu	*queue_ctx;
406 	unsigned int		nr_queues;
407 
408 	unsigned int		queue_depth;
409 
410 	/* hw dispatch queues */
411 	struct blk_mq_hw_ctx	**queue_hw_ctx;
412 	unsigned int		nr_hw_queues;
413 
414 	struct backing_dev_info	*backing_dev_info;
415 
416 	/*
417 	 * The queue owner gets to use this for whatever they like.
418 	 * ll_rw_blk doesn't touch it.
419 	 */
420 	void			*queuedata;
421 
422 	/*
423 	 * various queue flags, see QUEUE_* below
424 	 */
425 	unsigned long		queue_flags;
426 	/*
427 	 * Number of contexts that have called blk_set_pm_only(). If this
428 	 * counter is above zero then only RQF_PM and RQF_PREEMPT requests are
429 	 * processed.
430 	 */
431 	atomic_t		pm_only;
432 
433 	/*
434 	 * ida allocated id for this queue.  Used to index queues from
435 	 * ioctx.
436 	 */
437 	int			id;
438 
439 	/*
440 	 * queue needs bounce pages for pages above this limit
441 	 */
442 	gfp_t			bounce_gfp;
443 
444 	spinlock_t		queue_lock;
445 
446 	/*
447 	 * queue kobject
448 	 */
449 	struct kobject kobj;
450 
451 	/*
452 	 * mq queue kobject
453 	 */
454 	struct kobject *mq_kobj;
455 
456 #ifdef  CONFIG_BLK_DEV_INTEGRITY
457 	struct blk_integrity integrity;
458 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
459 
460 #ifdef CONFIG_PM
461 	struct device		*dev;
462 	int			rpm_status;
463 	unsigned int		nr_pending;
464 #endif
465 
466 	/*
467 	 * queue settings
468 	 */
469 	unsigned long		nr_requests;	/* Max # of requests */
470 
471 	unsigned int		dma_drain_size;
472 	void			*dma_drain_buffer;
473 	unsigned int		dma_pad_mask;
474 	unsigned int		dma_alignment;
475 
476 	unsigned int		rq_timeout;
477 	int			poll_nsec;
478 
479 	struct blk_stat_callback	*poll_cb;
480 	struct blk_rq_stat	poll_stat[BLK_MQ_POLL_STATS_BKTS];
481 
482 	struct timer_list	timeout;
483 	struct work_struct	timeout_work;
484 
485 	struct list_head	icq_list;
486 #ifdef CONFIG_BLK_CGROUP
487 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
488 	struct blkcg_gq		*root_blkg;
489 	struct list_head	blkg_list;
490 #endif
491 
492 	struct queue_limits	limits;
493 
494 #ifdef CONFIG_BLK_DEV_ZONED
495 	/*
496 	 * Zoned block device information for request dispatch control.
497 	 * nr_zones is the total number of zones of the device. This is always
498 	 * 0 for regular block devices. seq_zones_bitmap is a bitmap of nr_zones
499 	 * bits which indicates if a zone is conventional (bit clear) or
500 	 * sequential (bit set). seq_zones_wlock is a bitmap of nr_zones
501 	 * bits which indicates if a zone is write locked, that is, if a write
502 	 * request targeting the zone was dispatched. All three fields are
503 	 * initialized by the low level device driver (e.g. scsi/sd.c).
504 	 * Stacking drivers (device mappers) may or may not initialize
505 	 * these fields.
506 	 *
507 	 * Reads of this information must be protected with blk_queue_enter() /
508 	 * blk_queue_exit(). Modifying this information is only allowed while
509 	 * no requests are being processed. See also blk_mq_freeze_queue() and
510 	 * blk_mq_unfreeze_queue().
511 	 */
512 	unsigned int		nr_zones;
513 	unsigned long		*seq_zones_bitmap;
514 	unsigned long		*seq_zones_wlock;
515 #endif /* CONFIG_BLK_DEV_ZONED */
516 
517 	/*
518 	 * sg stuff
519 	 */
520 	unsigned int		sg_timeout;
521 	unsigned int		sg_reserved_size;
522 	int			node;
523 #ifdef CONFIG_BLK_DEV_IO_TRACE
524 	struct blk_trace	*blk_trace;
525 	struct mutex		blk_trace_mutex;
526 #endif
527 	/*
528 	 * for flush operations
529 	 */
530 	struct blk_flush_queue	*fq;
531 
532 	struct list_head	requeue_list;
533 	spinlock_t		requeue_lock;
534 	struct delayed_work	requeue_work;
535 
536 	struct mutex		sysfs_lock;
537 
538 	/*
539 	 * for reusing dead hctx instance in case of updating
540 	 * nr_hw_queues
541 	 */
542 	struct list_head	unused_hctx_list;
543 	spinlock_t		unused_hctx_lock;
544 
545 	int			mq_freeze_depth;
546 
547 #if defined(CONFIG_BLK_DEV_BSG)
548 	struct bsg_class_device bsg_dev;
549 #endif
550 
551 #ifdef CONFIG_BLK_DEV_THROTTLING
552 	/* Throttle data */
553 	struct throtl_data *td;
554 #endif
555 	struct rcu_head		rcu_head;
556 	wait_queue_head_t	mq_freeze_wq;
557 	/*
558 	 * Protect concurrent access to q_usage_counter by
559 	 * percpu_ref_kill() and percpu_ref_reinit().
560 	 */
561 	struct mutex		mq_freeze_lock;
562 	struct percpu_ref	q_usage_counter;
563 
564 	struct blk_mq_tag_set	*tag_set;
565 	struct list_head	tag_set_list;
566 	struct bio_set		bio_split;
567 
568 #ifdef CONFIG_BLK_DEBUG_FS
569 	struct dentry		*debugfs_dir;
570 	struct dentry		*sched_debugfs_dir;
571 	struct dentry		*rqos_debugfs_dir;
572 #endif
573 
574 	bool			mq_sysfs_init_done;
575 
576 	size_t			cmd_size;
577 
578 	struct work_struct	release_work;
579 
580 #define BLK_MAX_WRITE_HINTS	5
581 	u64			write_hints[BLK_MAX_WRITE_HINTS];
582 };
583 
584 #define QUEUE_FLAG_STOPPED	0	/* queue is stopped */
585 #define QUEUE_FLAG_DYING	1	/* queue being torn down */
586 #define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
587 #define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
588 #define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
589 #define QUEUE_FLAG_NONROT	6	/* non-rotational device (SSD) */
590 #define QUEUE_FLAG_VIRT		QUEUE_FLAG_NONROT /* paravirt device */
591 #define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
592 #define QUEUE_FLAG_DISCARD	8	/* supports DISCARD */
593 #define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
594 #define QUEUE_FLAG_ADD_RANDOM	10	/* Contributes to random pool */
595 #define QUEUE_FLAG_SECERASE	11	/* supports secure erase */
596 #define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
597 #define QUEUE_FLAG_DEAD		13	/* queue tear-down finished */
598 #define QUEUE_FLAG_INIT_DONE	14	/* queue is initialized */
599 #define QUEUE_FLAG_POLL		16	/* IO polling enabled if set */
600 #define QUEUE_FLAG_WC		17	/* Write back caching */
601 #define QUEUE_FLAG_FUA		18	/* device supports FUA writes */
602 #define QUEUE_FLAG_DAX		19	/* device supports DAX */
603 #define QUEUE_FLAG_STATS	20	/* track IO start and completion times */
604 #define QUEUE_FLAG_POLL_STATS	21	/* collecting stats for hybrid polling */
605 #define QUEUE_FLAG_REGISTERED	22	/* queue has been registered to a disk */
606 #define QUEUE_FLAG_SCSI_PASSTHROUGH 23	/* queue supports SCSI commands */
607 #define QUEUE_FLAG_QUIESCED	24	/* queue has been quiesced */
608 #define QUEUE_FLAG_PCI_P2PDMA	25	/* device supports PCI p2p requests */
609 
610 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
611 				 (1 << QUEUE_FLAG_SAME_COMP))
612 
613 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
614 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
615 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
616 
617 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
618 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
619 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
620 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
621 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
622 #define blk_queue_noxmerges(q)	\
623 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
624 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
625 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
626 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
627 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
628 #define blk_queue_secure_erase(q) \
629 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
630 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
631 #define blk_queue_scsi_passthrough(q)	\
632 	test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
633 #define blk_queue_pci_p2pdma(q)	\
634 	test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
635 
636 #define blk_noretry_request(rq) \
637 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
638 			     REQ_FAILFAST_DRIVER))
639 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
640 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
641 #define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
642 
643 extern void blk_set_pm_only(struct request_queue *q);
644 extern void blk_clear_pm_only(struct request_queue *q);
645 
646 static inline bool blk_account_rq(struct request *rq)
647 {
648 	return (rq->rq_flags & RQF_STARTED) && !blk_rq_is_passthrough(rq);
649 }
650 
651 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
652 
653 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
654 
655 #define rq_dma_dir(rq) \
656 	(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
657 
658 #define dma_map_bvec(dev, bv, dir, attrs) \
659 	dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
660 	(dir), (attrs))
661 
662 static inline bool queue_is_mq(struct request_queue *q)
663 {
664 	return q->mq_ops;
665 }
666 
667 static inline enum blk_zoned_model
668 blk_queue_zoned_model(struct request_queue *q)
669 {
670 	return q->limits.zoned;
671 }
672 
673 static inline bool blk_queue_is_zoned(struct request_queue *q)
674 {
675 	switch (blk_queue_zoned_model(q)) {
676 	case BLK_ZONED_HA:
677 	case BLK_ZONED_HM:
678 		return true;
679 	default:
680 		return false;
681 	}
682 }
683 
684 static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
685 {
686 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
687 }
688 
689 #ifdef CONFIG_BLK_DEV_ZONED
690 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
691 {
692 	return blk_queue_is_zoned(q) ? q->nr_zones : 0;
693 }
694 
695 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
696 					     sector_t sector)
697 {
698 	if (!blk_queue_is_zoned(q))
699 		return 0;
700 	return sector >> ilog2(q->limits.chunk_sectors);
701 }
702 
703 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
704 					 sector_t sector)
705 {
706 	if (!blk_queue_is_zoned(q) || !q->seq_zones_bitmap)
707 		return false;
708 	return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
709 }
710 #else /* CONFIG_BLK_DEV_ZONED */
711 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
712 {
713 	return 0;
714 }
715 #endif /* CONFIG_BLK_DEV_ZONED */
716 
717 static inline bool rq_is_sync(struct request *rq)
718 {
719 	return op_is_sync(rq->cmd_flags);
720 }
721 
722 static inline bool rq_mergeable(struct request *rq)
723 {
724 	if (blk_rq_is_passthrough(rq))
725 		return false;
726 
727 	if (req_op(rq) == REQ_OP_FLUSH)
728 		return false;
729 
730 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
731 		return false;
732 
733 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
734 		return false;
735 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
736 		return false;
737 
738 	return true;
739 }
740 
741 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
742 {
743 	if (bio_page(a) == bio_page(b) &&
744 	    bio_offset(a) == bio_offset(b))
745 		return true;
746 
747 	return false;
748 }
749 
750 static inline unsigned int blk_queue_depth(struct request_queue *q)
751 {
752 	if (q->queue_depth)
753 		return q->queue_depth;
754 
755 	return q->nr_requests;
756 }
757 
758 extern unsigned long blk_max_low_pfn, blk_max_pfn;
759 
760 /*
761  * standard bounce addresses:
762  *
763  * BLK_BOUNCE_HIGH	: bounce all highmem pages
764  * BLK_BOUNCE_ANY	: don't bounce anything
765  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
766  */
767 
768 #if BITS_PER_LONG == 32
769 #define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
770 #else
771 #define BLK_BOUNCE_HIGH		-1ULL
772 #endif
773 #define BLK_BOUNCE_ANY		(-1ULL)
774 #define BLK_BOUNCE_ISA		(DMA_BIT_MASK(24))
775 
776 /*
777  * default timeout for SG_IO if none specified
778  */
779 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
780 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
781 
782 struct rq_map_data {
783 	struct page **pages;
784 	int page_order;
785 	int nr_entries;
786 	unsigned long offset;
787 	int null_mapped;
788 	int from_user;
789 };
790 
791 struct req_iterator {
792 	struct bvec_iter iter;
793 	struct bio *bio;
794 };
795 
796 /* This should not be used directly - use rq_for_each_segment */
797 #define for_each_bio(_bio)		\
798 	for (; _bio; _bio = _bio->bi_next)
799 #define __rq_for_each_bio(_bio, rq)	\
800 	if ((rq->bio))			\
801 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
802 
803 #define rq_for_each_segment(bvl, _rq, _iter)			\
804 	__rq_for_each_bio(_iter.bio, _rq)			\
805 		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
806 
807 #define rq_for_each_bvec(bvl, _rq, _iter)			\
808 	__rq_for_each_bio(_iter.bio, _rq)			\
809 		bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
810 
811 #define rq_iter_last(bvec, _iter)				\
812 		(_iter.bio->bi_next == NULL &&			\
813 		 bio_iter_last(bvec, _iter.iter))
814 
815 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
816 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
817 #endif
818 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
819 extern void rq_flush_dcache_pages(struct request *rq);
820 #else
821 static inline void rq_flush_dcache_pages(struct request *rq)
822 {
823 }
824 #endif
825 
826 extern int blk_register_queue(struct gendisk *disk);
827 extern void blk_unregister_queue(struct gendisk *disk);
828 extern blk_qc_t generic_make_request(struct bio *bio);
829 extern blk_qc_t direct_make_request(struct bio *bio);
830 extern void blk_rq_init(struct request_queue *q, struct request *rq);
831 extern void blk_put_request(struct request *);
832 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
833 				       blk_mq_req_flags_t flags);
834 extern int blk_lld_busy(struct request_queue *q);
835 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
836 			     struct bio_set *bs, gfp_t gfp_mask,
837 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
838 			     void *data);
839 extern void blk_rq_unprep_clone(struct request *rq);
840 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
841 				     struct request *rq);
842 extern int blk_rq_append_bio(struct request *rq, struct bio **bio);
843 extern void blk_queue_split(struct request_queue *, struct bio **);
844 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
845 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
846 			      unsigned int, void __user *);
847 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
848 			  unsigned int, void __user *);
849 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
850 			 struct scsi_ioctl_command __user *);
851 
852 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
853 extern void blk_queue_exit(struct request_queue *q);
854 extern void blk_sync_queue(struct request_queue *q);
855 extern int blk_rq_map_user(struct request_queue *, struct request *,
856 			   struct rq_map_data *, void __user *, unsigned long,
857 			   gfp_t);
858 extern int blk_rq_unmap_user(struct bio *);
859 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
860 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
861 			       struct rq_map_data *, const struct iov_iter *,
862 			       gfp_t);
863 extern void blk_execute_rq(struct request_queue *, struct gendisk *,
864 			  struct request *, int);
865 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
866 				  struct request *, int, rq_end_io_fn *);
867 
868 /* Helper to convert REQ_OP_XXX to its string format XXX */
869 extern const char *blk_op_str(unsigned int op);
870 
871 int blk_status_to_errno(blk_status_t status);
872 blk_status_t errno_to_blk_status(int errno);
873 
874 int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin);
875 
876 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
877 {
878 	return bdev->bd_disk->queue;	/* this is never NULL */
879 }
880 
881 /*
882  * The basic unit of block I/O is a sector. It is used in a number of contexts
883  * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
884  * bytes. Variables of type sector_t represent an offset or size that is a
885  * multiple of 512 bytes. Hence these two constants.
886  */
887 #ifndef SECTOR_SHIFT
888 #define SECTOR_SHIFT 9
889 #endif
890 #ifndef SECTOR_SIZE
891 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
892 #endif
893 
894 /*
895  * blk_rq_pos()			: the current sector
896  * blk_rq_bytes()		: bytes left in the entire request
897  * blk_rq_cur_bytes()		: bytes left in the current segment
898  * blk_rq_err_bytes()		: bytes left till the next error boundary
899  * blk_rq_sectors()		: sectors left in the entire request
900  * blk_rq_cur_sectors()		: sectors left in the current segment
901  */
902 static inline sector_t blk_rq_pos(const struct request *rq)
903 {
904 	return rq->__sector;
905 }
906 
907 static inline unsigned int blk_rq_bytes(const struct request *rq)
908 {
909 	return rq->__data_len;
910 }
911 
912 static inline int blk_rq_cur_bytes(const struct request *rq)
913 {
914 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
915 }
916 
917 extern unsigned int blk_rq_err_bytes(const struct request *rq);
918 
919 static inline unsigned int blk_rq_sectors(const struct request *rq)
920 {
921 	return blk_rq_bytes(rq) >> SECTOR_SHIFT;
922 }
923 
924 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
925 {
926 	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
927 }
928 
929 #ifdef CONFIG_BLK_DEV_ZONED
930 static inline unsigned int blk_rq_zone_no(struct request *rq)
931 {
932 	return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
933 }
934 
935 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
936 {
937 	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
938 }
939 #endif /* CONFIG_BLK_DEV_ZONED */
940 
941 /*
942  * Some commands like WRITE SAME have a payload or data transfer size which
943  * is different from the size of the request.  Any driver that supports such
944  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
945  * calculate the data transfer size.
946  */
947 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
948 {
949 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
950 		return rq->special_vec.bv_len;
951 	return blk_rq_bytes(rq);
952 }
953 
954 /*
955  * Return the first full biovec in the request.  The caller needs to check that
956  * there are any bvecs before calling this helper.
957  */
958 static inline struct bio_vec req_bvec(struct request *rq)
959 {
960 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
961 		return rq->special_vec;
962 	return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
963 }
964 
965 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
966 						     int op)
967 {
968 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
969 		return min(q->limits.max_discard_sectors,
970 			   UINT_MAX >> SECTOR_SHIFT);
971 
972 	if (unlikely(op == REQ_OP_WRITE_SAME))
973 		return q->limits.max_write_same_sectors;
974 
975 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
976 		return q->limits.max_write_zeroes_sectors;
977 
978 	return q->limits.max_sectors;
979 }
980 
981 /*
982  * Return maximum size of a request at given offset. Only valid for
983  * file system requests.
984  */
985 static inline unsigned int blk_max_size_offset(struct request_queue *q,
986 					       sector_t offset)
987 {
988 	if (!q->limits.chunk_sectors)
989 		return q->limits.max_sectors;
990 
991 	return min(q->limits.max_sectors, (unsigned int)(q->limits.chunk_sectors -
992 			(offset & (q->limits.chunk_sectors - 1))));
993 }
994 
995 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
996 						  sector_t offset)
997 {
998 	struct request_queue *q = rq->q;
999 
1000 	if (blk_rq_is_passthrough(rq))
1001 		return q->limits.max_hw_sectors;
1002 
1003 	if (!q->limits.chunk_sectors ||
1004 	    req_op(rq) == REQ_OP_DISCARD ||
1005 	    req_op(rq) == REQ_OP_SECURE_ERASE)
1006 		return blk_queue_get_max_sectors(q, req_op(rq));
1007 
1008 	return min(blk_max_size_offset(q, offset),
1009 			blk_queue_get_max_sectors(q, req_op(rq)));
1010 }
1011 
1012 static inline unsigned int blk_rq_count_bios(struct request *rq)
1013 {
1014 	unsigned int nr_bios = 0;
1015 	struct bio *bio;
1016 
1017 	__rq_for_each_bio(bio, rq)
1018 		nr_bios++;
1019 
1020 	return nr_bios;
1021 }
1022 
1023 void blk_steal_bios(struct bio_list *list, struct request *rq);
1024 
1025 /*
1026  * Request completion related functions.
1027  *
1028  * blk_update_request() completes given number of bytes and updates
1029  * the request without completing it.
1030  */
1031 extern bool blk_update_request(struct request *rq, blk_status_t error,
1032 			       unsigned int nr_bytes);
1033 
1034 extern void __blk_complete_request(struct request *);
1035 extern void blk_abort_request(struct request *);
1036 
1037 /*
1038  * Access functions for manipulating queue properties
1039  */
1040 extern void blk_cleanup_queue(struct request_queue *);
1041 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1042 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1043 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1044 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1045 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1046 extern void blk_queue_max_discard_segments(struct request_queue *,
1047 		unsigned short);
1048 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1049 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1050 		unsigned int max_discard_sectors);
1051 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1052 		unsigned int max_write_same_sectors);
1053 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1054 		unsigned int max_write_same_sectors);
1055 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
1056 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1057 extern void blk_queue_alignment_offset(struct request_queue *q,
1058 				       unsigned int alignment);
1059 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1060 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1061 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1062 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1063 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1064 extern void blk_set_default_limits(struct queue_limits *lim);
1065 extern void blk_set_stacking_limits(struct queue_limits *lim);
1066 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1067 			    sector_t offset);
1068 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1069 			    sector_t offset);
1070 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1071 			      sector_t offset);
1072 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1073 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1074 extern int blk_queue_dma_drain(struct request_queue *q,
1075 			       dma_drain_needed_fn *dma_drain_needed,
1076 			       void *buf, unsigned int size);
1077 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1078 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1079 extern void blk_queue_dma_alignment(struct request_queue *, int);
1080 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1081 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1082 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1083 
1084 /*
1085  * Number of physical segments as sent to the device.
1086  *
1087  * Normally this is the number of discontiguous data segments sent by the
1088  * submitter.  But for data-less command like discard we might have no
1089  * actual data segments submitted, but the driver might have to add it's
1090  * own special payload.  In that case we still return 1 here so that this
1091  * special payload will be mapped.
1092  */
1093 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1094 {
1095 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1096 		return 1;
1097 	return rq->nr_phys_segments;
1098 }
1099 
1100 /*
1101  * Number of discard segments (or ranges) the driver needs to fill in.
1102  * Each discard bio merged into a request is counted as one segment.
1103  */
1104 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1105 {
1106 	return max_t(unsigned short, rq->nr_phys_segments, 1);
1107 }
1108 
1109 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1110 extern void blk_dump_rq_flags(struct request *, char *);
1111 extern long nr_blockdev_pages(void);
1112 
1113 bool __must_check blk_get_queue(struct request_queue *);
1114 struct request_queue *blk_alloc_queue(gfp_t);
1115 struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id);
1116 extern void blk_put_queue(struct request_queue *);
1117 extern void blk_set_queue_dying(struct request_queue *);
1118 
1119 /*
1120  * blk_plug permits building a queue of related requests by holding the I/O
1121  * fragments for a short period. This allows merging of sequential requests
1122  * into single larger request. As the requests are moved from a per-task list to
1123  * the device's request_queue in a batch, this results in improved scalability
1124  * as the lock contention for request_queue lock is reduced.
1125  *
1126  * It is ok not to disable preemption when adding the request to the plug list
1127  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1128  * the plug list when the task sleeps by itself. For details, please see
1129  * schedule() where blk_schedule_flush_plug() is called.
1130  */
1131 struct blk_plug {
1132 	struct list_head mq_list; /* blk-mq requests */
1133 	struct list_head cb_list; /* md requires an unplug callback */
1134 	unsigned short rq_count;
1135 	bool multiple_queues;
1136 };
1137 #define BLK_MAX_REQUEST_COUNT 16
1138 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1139 
1140 struct blk_plug_cb;
1141 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1142 struct blk_plug_cb {
1143 	struct list_head list;
1144 	blk_plug_cb_fn callback;
1145 	void *data;
1146 };
1147 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1148 					     void *data, int size);
1149 extern void blk_start_plug(struct blk_plug *);
1150 extern void blk_finish_plug(struct blk_plug *);
1151 extern void blk_flush_plug_list(struct blk_plug *, bool);
1152 
1153 static inline void blk_flush_plug(struct task_struct *tsk)
1154 {
1155 	struct blk_plug *plug = tsk->plug;
1156 
1157 	if (plug)
1158 		blk_flush_plug_list(plug, false);
1159 }
1160 
1161 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1162 {
1163 	struct blk_plug *plug = tsk->plug;
1164 
1165 	if (plug)
1166 		blk_flush_plug_list(plug, true);
1167 }
1168 
1169 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1170 {
1171 	struct blk_plug *plug = tsk->plug;
1172 
1173 	return plug &&
1174 		 (!list_empty(&plug->mq_list) ||
1175 		 !list_empty(&plug->cb_list));
1176 }
1177 
1178 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1179 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1180 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1181 
1182 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
1183 
1184 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1185 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1186 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1187 		sector_t nr_sects, gfp_t gfp_mask, int flags,
1188 		struct bio **biop);
1189 
1190 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
1191 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
1192 
1193 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1194 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1195 		unsigned flags);
1196 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1197 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1198 
1199 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1200 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1201 {
1202 	return blkdev_issue_discard(sb->s_bdev,
1203 				    block << (sb->s_blocksize_bits -
1204 					      SECTOR_SHIFT),
1205 				    nr_blocks << (sb->s_blocksize_bits -
1206 						  SECTOR_SHIFT),
1207 				    gfp_mask, flags);
1208 }
1209 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1210 		sector_t nr_blocks, gfp_t gfp_mask)
1211 {
1212 	return blkdev_issue_zeroout(sb->s_bdev,
1213 				    block << (sb->s_blocksize_bits -
1214 					      SECTOR_SHIFT),
1215 				    nr_blocks << (sb->s_blocksize_bits -
1216 						  SECTOR_SHIFT),
1217 				    gfp_mask, 0);
1218 }
1219 
1220 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1221 
1222 enum blk_default_limits {
1223 	BLK_MAX_SEGMENTS	= 128,
1224 	BLK_SAFE_MAX_SECTORS	= 255,
1225 	BLK_DEF_MAX_SECTORS	= 2560,
1226 	BLK_MAX_SEGMENT_SIZE	= 65536,
1227 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
1228 };
1229 
1230 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1231 {
1232 	return q->limits.seg_boundary_mask;
1233 }
1234 
1235 static inline unsigned long queue_virt_boundary(struct request_queue *q)
1236 {
1237 	return q->limits.virt_boundary_mask;
1238 }
1239 
1240 static inline unsigned int queue_max_sectors(struct request_queue *q)
1241 {
1242 	return q->limits.max_sectors;
1243 }
1244 
1245 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1246 {
1247 	return q->limits.max_hw_sectors;
1248 }
1249 
1250 static inline unsigned short queue_max_segments(struct request_queue *q)
1251 {
1252 	return q->limits.max_segments;
1253 }
1254 
1255 static inline unsigned short queue_max_discard_segments(struct request_queue *q)
1256 {
1257 	return q->limits.max_discard_segments;
1258 }
1259 
1260 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1261 {
1262 	return q->limits.max_segment_size;
1263 }
1264 
1265 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1266 {
1267 	int retval = 512;
1268 
1269 	if (q && q->limits.logical_block_size)
1270 		retval = q->limits.logical_block_size;
1271 
1272 	return retval;
1273 }
1274 
1275 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1276 {
1277 	return queue_logical_block_size(bdev_get_queue(bdev));
1278 }
1279 
1280 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1281 {
1282 	return q->limits.physical_block_size;
1283 }
1284 
1285 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1286 {
1287 	return queue_physical_block_size(bdev_get_queue(bdev));
1288 }
1289 
1290 static inline unsigned int queue_io_min(struct request_queue *q)
1291 {
1292 	return q->limits.io_min;
1293 }
1294 
1295 static inline int bdev_io_min(struct block_device *bdev)
1296 {
1297 	return queue_io_min(bdev_get_queue(bdev));
1298 }
1299 
1300 static inline unsigned int queue_io_opt(struct request_queue *q)
1301 {
1302 	return q->limits.io_opt;
1303 }
1304 
1305 static inline int bdev_io_opt(struct block_device *bdev)
1306 {
1307 	return queue_io_opt(bdev_get_queue(bdev));
1308 }
1309 
1310 static inline int queue_alignment_offset(struct request_queue *q)
1311 {
1312 	if (q->limits.misaligned)
1313 		return -1;
1314 
1315 	return q->limits.alignment_offset;
1316 }
1317 
1318 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1319 {
1320 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1321 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1322 		<< SECTOR_SHIFT;
1323 
1324 	return (granularity + lim->alignment_offset - alignment) % granularity;
1325 }
1326 
1327 static inline int bdev_alignment_offset(struct block_device *bdev)
1328 {
1329 	struct request_queue *q = bdev_get_queue(bdev);
1330 
1331 	if (q->limits.misaligned)
1332 		return -1;
1333 
1334 	if (bdev != bdev->bd_contains)
1335 		return bdev->bd_part->alignment_offset;
1336 
1337 	return q->limits.alignment_offset;
1338 }
1339 
1340 static inline int queue_discard_alignment(struct request_queue *q)
1341 {
1342 	if (q->limits.discard_misaligned)
1343 		return -1;
1344 
1345 	return q->limits.discard_alignment;
1346 }
1347 
1348 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1349 {
1350 	unsigned int alignment, granularity, offset;
1351 
1352 	if (!lim->max_discard_sectors)
1353 		return 0;
1354 
1355 	/* Why are these in bytes, not sectors? */
1356 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
1357 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
1358 	if (!granularity)
1359 		return 0;
1360 
1361 	/* Offset of the partition start in 'granularity' sectors */
1362 	offset = sector_div(sector, granularity);
1363 
1364 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
1365 	offset = (granularity + alignment - offset) % granularity;
1366 
1367 	/* Turn it back into bytes, gaah */
1368 	return offset << SECTOR_SHIFT;
1369 }
1370 
1371 static inline int bdev_discard_alignment(struct block_device *bdev)
1372 {
1373 	struct request_queue *q = bdev_get_queue(bdev);
1374 
1375 	if (bdev != bdev->bd_contains)
1376 		return bdev->bd_part->discard_alignment;
1377 
1378 	return q->limits.discard_alignment;
1379 }
1380 
1381 static inline unsigned int bdev_write_same(struct block_device *bdev)
1382 {
1383 	struct request_queue *q = bdev_get_queue(bdev);
1384 
1385 	if (q)
1386 		return q->limits.max_write_same_sectors;
1387 
1388 	return 0;
1389 }
1390 
1391 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1392 {
1393 	struct request_queue *q = bdev_get_queue(bdev);
1394 
1395 	if (q)
1396 		return q->limits.max_write_zeroes_sectors;
1397 
1398 	return 0;
1399 }
1400 
1401 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1402 {
1403 	struct request_queue *q = bdev_get_queue(bdev);
1404 
1405 	if (q)
1406 		return blk_queue_zoned_model(q);
1407 
1408 	return BLK_ZONED_NONE;
1409 }
1410 
1411 static inline bool bdev_is_zoned(struct block_device *bdev)
1412 {
1413 	struct request_queue *q = bdev_get_queue(bdev);
1414 
1415 	if (q)
1416 		return blk_queue_is_zoned(q);
1417 
1418 	return false;
1419 }
1420 
1421 static inline unsigned int bdev_zone_sectors(struct block_device *bdev)
1422 {
1423 	struct request_queue *q = bdev_get_queue(bdev);
1424 
1425 	if (q)
1426 		return blk_queue_zone_sectors(q);
1427 	return 0;
1428 }
1429 
1430 static inline int queue_dma_alignment(struct request_queue *q)
1431 {
1432 	return q ? q->dma_alignment : 511;
1433 }
1434 
1435 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1436 				 unsigned int len)
1437 {
1438 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1439 	return !(addr & alignment) && !(len & alignment);
1440 }
1441 
1442 /* assumes size > 256 */
1443 static inline unsigned int blksize_bits(unsigned int size)
1444 {
1445 	unsigned int bits = 8;
1446 	do {
1447 		bits++;
1448 		size >>= 1;
1449 	} while (size > 256);
1450 	return bits;
1451 }
1452 
1453 static inline unsigned int block_size(struct block_device *bdev)
1454 {
1455 	return bdev->bd_block_size;
1456 }
1457 
1458 typedef struct {struct page *v;} Sector;
1459 
1460 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1461 
1462 static inline void put_dev_sector(Sector p)
1463 {
1464 	put_page(p.v);
1465 }
1466 
1467 int kblockd_schedule_work(struct work_struct *work);
1468 int kblockd_schedule_work_on(int cpu, struct work_struct *work);
1469 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1470 
1471 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1472 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1473 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1474 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1475 
1476 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1477 
1478 enum blk_integrity_flags {
1479 	BLK_INTEGRITY_VERIFY		= 1 << 0,
1480 	BLK_INTEGRITY_GENERATE		= 1 << 1,
1481 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
1482 	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
1483 };
1484 
1485 struct blk_integrity_iter {
1486 	void			*prot_buf;
1487 	void			*data_buf;
1488 	sector_t		seed;
1489 	unsigned int		data_size;
1490 	unsigned short		interval;
1491 	const char		*disk_name;
1492 };
1493 
1494 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1495 
1496 struct blk_integrity_profile {
1497 	integrity_processing_fn		*generate_fn;
1498 	integrity_processing_fn		*verify_fn;
1499 	const char			*name;
1500 };
1501 
1502 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1503 extern void blk_integrity_unregister(struct gendisk *);
1504 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1505 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1506 				   struct scatterlist *);
1507 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1508 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1509 				   struct request *);
1510 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1511 				    struct bio *);
1512 
1513 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1514 {
1515 	struct blk_integrity *bi = &disk->queue->integrity;
1516 
1517 	if (!bi->profile)
1518 		return NULL;
1519 
1520 	return bi;
1521 }
1522 
1523 static inline
1524 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1525 {
1526 	return blk_get_integrity(bdev->bd_disk);
1527 }
1528 
1529 static inline bool blk_integrity_rq(struct request *rq)
1530 {
1531 	return rq->cmd_flags & REQ_INTEGRITY;
1532 }
1533 
1534 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1535 						    unsigned int segs)
1536 {
1537 	q->limits.max_integrity_segments = segs;
1538 }
1539 
1540 static inline unsigned short
1541 queue_max_integrity_segments(struct request_queue *q)
1542 {
1543 	return q->limits.max_integrity_segments;
1544 }
1545 
1546 /**
1547  * bio_integrity_intervals - Return number of integrity intervals for a bio
1548  * @bi:		blk_integrity profile for device
1549  * @sectors:	Size of the bio in 512-byte sectors
1550  *
1551  * Description: The block layer calculates everything in 512 byte
1552  * sectors but integrity metadata is done in terms of the data integrity
1553  * interval size of the storage device.  Convert the block layer sectors
1554  * to the appropriate number of integrity intervals.
1555  */
1556 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1557 						   unsigned int sectors)
1558 {
1559 	return sectors >> (bi->interval_exp - 9);
1560 }
1561 
1562 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1563 					       unsigned int sectors)
1564 {
1565 	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
1566 }
1567 
1568 /*
1569  * Return the first bvec that contains integrity data.  Only drivers that are
1570  * limited to a single integrity segment should use this helper.
1571  */
1572 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1573 {
1574 	if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
1575 		return NULL;
1576 	return rq->bio->bi_integrity->bip_vec;
1577 }
1578 
1579 #else /* CONFIG_BLK_DEV_INTEGRITY */
1580 
1581 struct bio;
1582 struct block_device;
1583 struct gendisk;
1584 struct blk_integrity;
1585 
1586 static inline int blk_integrity_rq(struct request *rq)
1587 {
1588 	return 0;
1589 }
1590 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1591 					    struct bio *b)
1592 {
1593 	return 0;
1594 }
1595 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1596 					  struct bio *b,
1597 					  struct scatterlist *s)
1598 {
1599 	return 0;
1600 }
1601 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1602 {
1603 	return NULL;
1604 }
1605 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1606 {
1607 	return NULL;
1608 }
1609 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1610 {
1611 	return 0;
1612 }
1613 static inline void blk_integrity_register(struct gendisk *d,
1614 					 struct blk_integrity *b)
1615 {
1616 }
1617 static inline void blk_integrity_unregister(struct gendisk *d)
1618 {
1619 }
1620 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1621 						    unsigned int segs)
1622 {
1623 }
1624 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1625 {
1626 	return 0;
1627 }
1628 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1629 					  struct request *r1,
1630 					  struct request *r2)
1631 {
1632 	return true;
1633 }
1634 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1635 					   struct request *r,
1636 					   struct bio *b)
1637 {
1638 	return true;
1639 }
1640 
1641 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1642 						   unsigned int sectors)
1643 {
1644 	return 0;
1645 }
1646 
1647 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1648 					       unsigned int sectors)
1649 {
1650 	return 0;
1651 }
1652 
1653 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1654 {
1655 	return NULL;
1656 }
1657 
1658 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1659 
1660 struct block_device_operations {
1661 	int (*open) (struct block_device *, fmode_t);
1662 	void (*release) (struct gendisk *, fmode_t);
1663 	int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
1664 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1665 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1666 	unsigned int (*check_events) (struct gendisk *disk,
1667 				      unsigned int clearing);
1668 	/* ->media_changed() is DEPRECATED, use ->check_events() instead */
1669 	int (*media_changed) (struct gendisk *);
1670 	void (*unlock_native_capacity) (struct gendisk *);
1671 	int (*revalidate_disk) (struct gendisk *);
1672 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1673 	/* this callback is with swap_lock and sometimes page table lock held */
1674 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1675 	int (*report_zones)(struct gendisk *, sector_t sector,
1676 			    struct blk_zone *zones, unsigned int *nr_zones,
1677 			    gfp_t gfp_mask);
1678 	struct module *owner;
1679 	const struct pr_ops *pr_ops;
1680 };
1681 
1682 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1683 				 unsigned long);
1684 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1685 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1686 						struct writeback_control *);
1687 
1688 #ifdef CONFIG_BLK_DEV_ZONED
1689 bool blk_req_needs_zone_write_lock(struct request *rq);
1690 void __blk_req_zone_write_lock(struct request *rq);
1691 void __blk_req_zone_write_unlock(struct request *rq);
1692 
1693 static inline void blk_req_zone_write_lock(struct request *rq)
1694 {
1695 	if (blk_req_needs_zone_write_lock(rq))
1696 		__blk_req_zone_write_lock(rq);
1697 }
1698 
1699 static inline void blk_req_zone_write_unlock(struct request *rq)
1700 {
1701 	if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
1702 		__blk_req_zone_write_unlock(rq);
1703 }
1704 
1705 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1706 {
1707 	return rq->q->seq_zones_wlock &&
1708 		test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
1709 }
1710 
1711 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1712 {
1713 	if (!blk_req_needs_zone_write_lock(rq))
1714 		return true;
1715 	return !blk_req_zone_is_write_locked(rq);
1716 }
1717 #else
1718 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
1719 {
1720 	return false;
1721 }
1722 
1723 static inline void blk_req_zone_write_lock(struct request *rq)
1724 {
1725 }
1726 
1727 static inline void blk_req_zone_write_unlock(struct request *rq)
1728 {
1729 }
1730 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1731 {
1732 	return false;
1733 }
1734 
1735 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1736 {
1737 	return true;
1738 }
1739 #endif /* CONFIG_BLK_DEV_ZONED */
1740 
1741 #else /* CONFIG_BLOCK */
1742 
1743 struct block_device;
1744 
1745 /*
1746  * stubs for when the block layer is configured out
1747  */
1748 #define buffer_heads_over_limit 0
1749 
1750 static inline long nr_blockdev_pages(void)
1751 {
1752 	return 0;
1753 }
1754 
1755 struct blk_plug {
1756 };
1757 
1758 static inline void blk_start_plug(struct blk_plug *plug)
1759 {
1760 }
1761 
1762 static inline void blk_finish_plug(struct blk_plug *plug)
1763 {
1764 }
1765 
1766 static inline void blk_flush_plug(struct task_struct *task)
1767 {
1768 }
1769 
1770 static inline void blk_schedule_flush_plug(struct task_struct *task)
1771 {
1772 }
1773 
1774 
1775 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1776 {
1777 	return false;
1778 }
1779 
1780 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1781 				     sector_t *error_sector)
1782 {
1783 	return 0;
1784 }
1785 
1786 #endif /* CONFIG_BLOCK */
1787 
1788 static inline void blk_wake_io_task(struct task_struct *waiter)
1789 {
1790 	/*
1791 	 * If we're polling, the task itself is doing the completions. For
1792 	 * that case, we don't need to signal a wakeup, it's enough to just
1793 	 * mark us as RUNNING.
1794 	 */
1795 	if (waiter == current)
1796 		__set_current_state(TASK_RUNNING);
1797 	else
1798 		wake_up_process(waiter);
1799 }
1800 
1801 #endif
1802