xref: /linux-6.15/include/linux/blkdev.h (revision e742bd5c)
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 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
198 	/* Time that the first bio started allocating this request. */
199 	u64 alloc_time_ns;
200 #endif
201 	/* Time that this request was allocated for this IO. */
202 	u64 start_time_ns;
203 	/* Time that I/O was submitted to the device. */
204 	u64 io_start_time_ns;
205 
206 #ifdef CONFIG_BLK_WBT
207 	unsigned short wbt_flags;
208 #endif
209 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
210 	unsigned short throtl_size;
211 #endif
212 
213 	/*
214 	 * Number of scatter-gather DMA addr+len pairs after
215 	 * physical address coalescing is performed.
216 	 */
217 	unsigned short nr_phys_segments;
218 
219 #if defined(CONFIG_BLK_DEV_INTEGRITY)
220 	unsigned short nr_integrity_segments;
221 #endif
222 
223 	unsigned short write_hint;
224 	unsigned short ioprio;
225 
226 	unsigned int extra_len;	/* length of alignment and padding */
227 
228 	enum mq_rq_state state;
229 	refcount_t ref;
230 
231 	unsigned int timeout;
232 	unsigned long deadline;
233 
234 	union {
235 		struct __call_single_data csd;
236 		u64 fifo_time;
237 	};
238 
239 	/*
240 	 * completion callback.
241 	 */
242 	rq_end_io_fn *end_io;
243 	void *end_io_data;
244 };
245 
246 static inline bool blk_op_is_scsi(unsigned int op)
247 {
248 	return op == REQ_OP_SCSI_IN || op == REQ_OP_SCSI_OUT;
249 }
250 
251 static inline bool blk_op_is_private(unsigned int op)
252 {
253 	return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
254 }
255 
256 static inline bool blk_rq_is_scsi(struct request *rq)
257 {
258 	return blk_op_is_scsi(req_op(rq));
259 }
260 
261 static inline bool blk_rq_is_private(struct request *rq)
262 {
263 	return blk_op_is_private(req_op(rq));
264 }
265 
266 static inline bool blk_rq_is_passthrough(struct request *rq)
267 {
268 	return blk_rq_is_scsi(rq) || blk_rq_is_private(rq);
269 }
270 
271 static inline bool bio_is_passthrough(struct bio *bio)
272 {
273 	unsigned op = bio_op(bio);
274 
275 	return blk_op_is_scsi(op) || blk_op_is_private(op);
276 }
277 
278 static inline unsigned short req_get_ioprio(struct request *req)
279 {
280 	return req->ioprio;
281 }
282 
283 #include <linux/elevator.h>
284 
285 struct blk_queue_ctx;
286 
287 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
288 
289 struct bio_vec;
290 typedef int (dma_drain_needed_fn)(struct request *);
291 
292 enum blk_eh_timer_return {
293 	BLK_EH_DONE,		/* drivers has completed the command */
294 	BLK_EH_RESET_TIMER,	/* reset timer and try again */
295 };
296 
297 enum blk_queue_state {
298 	Queue_down,
299 	Queue_up,
300 };
301 
302 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
303 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
304 
305 #define BLK_SCSI_MAX_CMDS	(256)
306 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
307 
308 /*
309  * Zoned block device models (zoned limit).
310  */
311 enum blk_zoned_model {
312 	BLK_ZONED_NONE,	/* Regular block device */
313 	BLK_ZONED_HA,	/* Host-aware zoned block device */
314 	BLK_ZONED_HM,	/* Host-managed zoned block device */
315 };
316 
317 struct queue_limits {
318 	unsigned long		bounce_pfn;
319 	unsigned long		seg_boundary_mask;
320 	unsigned long		virt_boundary_mask;
321 
322 	unsigned int		max_hw_sectors;
323 	unsigned int		max_dev_sectors;
324 	unsigned int		chunk_sectors;
325 	unsigned int		max_sectors;
326 	unsigned int		max_segment_size;
327 	unsigned int		physical_block_size;
328 	unsigned int		alignment_offset;
329 	unsigned int		io_min;
330 	unsigned int		io_opt;
331 	unsigned int		max_discard_sectors;
332 	unsigned int		max_hw_discard_sectors;
333 	unsigned int		max_write_same_sectors;
334 	unsigned int		max_write_zeroes_sectors;
335 	unsigned int		discard_granularity;
336 	unsigned int		discard_alignment;
337 
338 	unsigned short		logical_block_size;
339 	unsigned short		max_segments;
340 	unsigned short		max_integrity_segments;
341 	unsigned short		max_discard_segments;
342 
343 	unsigned char		misaligned;
344 	unsigned char		discard_misaligned;
345 	unsigned char		raid_partial_stripes_expensive;
346 	enum blk_zoned_model	zoned;
347 };
348 
349 #ifdef CONFIG_BLK_DEV_ZONED
350 
351 /*
352  * Maximum number of zones to report with a single report zones command.
353  */
354 #define BLK_ZONED_REPORT_MAX_ZONES	8192U
355 
356 extern unsigned int blkdev_nr_zones(struct block_device *bdev);
357 extern int blkdev_report_zones(struct block_device *bdev,
358 			       sector_t sector, struct blk_zone *zones,
359 			       unsigned int *nr_zones);
360 extern int blkdev_reset_zones(struct block_device *bdev, sector_t sectors,
361 			      sector_t nr_sectors, gfp_t gfp_mask);
362 extern int blk_revalidate_disk_zones(struct gendisk *disk);
363 
364 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
365 				     unsigned int cmd, unsigned long arg);
366 extern int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
367 				    unsigned int cmd, unsigned long arg);
368 
369 #else /* CONFIG_BLK_DEV_ZONED */
370 
371 static inline unsigned int blkdev_nr_zones(struct block_device *bdev)
372 {
373 	return 0;
374 }
375 
376 static inline int blk_revalidate_disk_zones(struct gendisk *disk)
377 {
378 	return 0;
379 }
380 
381 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
382 					    fmode_t mode, unsigned int cmd,
383 					    unsigned long arg)
384 {
385 	return -ENOTTY;
386 }
387 
388 static inline int blkdev_reset_zones_ioctl(struct block_device *bdev,
389 					   fmode_t mode, unsigned int cmd,
390 					   unsigned long arg)
391 {
392 	return -ENOTTY;
393 }
394 
395 #endif /* CONFIG_BLK_DEV_ZONED */
396 
397 struct request_queue {
398 	struct request		*last_merge;
399 	struct elevator_queue	*elevator;
400 
401 	struct blk_queue_stats	*stats;
402 	struct rq_qos		*rq_qos;
403 
404 	make_request_fn		*make_request_fn;
405 	dma_drain_needed_fn	*dma_drain_needed;
406 
407 	const struct blk_mq_ops	*mq_ops;
408 
409 	/* sw queues */
410 	struct blk_mq_ctx __percpu	*queue_ctx;
411 	unsigned int		nr_queues;
412 
413 	unsigned int		queue_depth;
414 
415 	/* hw dispatch queues */
416 	struct blk_mq_hw_ctx	**queue_hw_ctx;
417 	unsigned int		nr_hw_queues;
418 
419 	struct backing_dev_info	*backing_dev_info;
420 
421 	/*
422 	 * The queue owner gets to use this for whatever they like.
423 	 * ll_rw_blk doesn't touch it.
424 	 */
425 	void			*queuedata;
426 
427 	/*
428 	 * various queue flags, see QUEUE_* below
429 	 */
430 	unsigned long		queue_flags;
431 	/*
432 	 * Number of contexts that have called blk_set_pm_only(). If this
433 	 * counter is above zero then only RQF_PM and RQF_PREEMPT requests are
434 	 * processed.
435 	 */
436 	atomic_t		pm_only;
437 
438 	/*
439 	 * ida allocated id for this queue.  Used to index queues from
440 	 * ioctx.
441 	 */
442 	int			id;
443 
444 	/*
445 	 * queue needs bounce pages for pages above this limit
446 	 */
447 	gfp_t			bounce_gfp;
448 
449 	spinlock_t		queue_lock;
450 
451 	/*
452 	 * queue kobject
453 	 */
454 	struct kobject kobj;
455 
456 	/*
457 	 * mq queue kobject
458 	 */
459 	struct kobject *mq_kobj;
460 
461 #ifdef  CONFIG_BLK_DEV_INTEGRITY
462 	struct blk_integrity integrity;
463 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
464 
465 #ifdef CONFIG_PM
466 	struct device		*dev;
467 	int			rpm_status;
468 	unsigned int		nr_pending;
469 #endif
470 
471 	/*
472 	 * queue settings
473 	 */
474 	unsigned long		nr_requests;	/* Max # of requests */
475 
476 	unsigned int		dma_drain_size;
477 	void			*dma_drain_buffer;
478 	unsigned int		dma_pad_mask;
479 	unsigned int		dma_alignment;
480 
481 	unsigned int		rq_timeout;
482 	int			poll_nsec;
483 
484 	struct blk_stat_callback	*poll_cb;
485 	struct blk_rq_stat	poll_stat[BLK_MQ_POLL_STATS_BKTS];
486 
487 	struct timer_list	timeout;
488 	struct work_struct	timeout_work;
489 
490 	struct list_head	icq_list;
491 #ifdef CONFIG_BLK_CGROUP
492 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
493 	struct blkcg_gq		*root_blkg;
494 	struct list_head	blkg_list;
495 #endif
496 
497 	struct queue_limits	limits;
498 
499 	unsigned int		required_elevator_features;
500 
501 #ifdef CONFIG_BLK_DEV_ZONED
502 	/*
503 	 * Zoned block device information for request dispatch control.
504 	 * nr_zones is the total number of zones of the device. This is always
505 	 * 0 for regular block devices. seq_zones_bitmap is a bitmap of nr_zones
506 	 * bits which indicates if a zone is conventional (bit clear) or
507 	 * sequential (bit set). seq_zones_wlock is a bitmap of nr_zones
508 	 * bits which indicates if a zone is write locked, that is, if a write
509 	 * request targeting the zone was dispatched. All three fields are
510 	 * initialized by the low level device driver (e.g. scsi/sd.c).
511 	 * Stacking drivers (device mappers) may or may not initialize
512 	 * these fields.
513 	 *
514 	 * Reads of this information must be protected with blk_queue_enter() /
515 	 * blk_queue_exit(). Modifying this information is only allowed while
516 	 * no requests are being processed. See also blk_mq_freeze_queue() and
517 	 * blk_mq_unfreeze_queue().
518 	 */
519 	unsigned int		nr_zones;
520 	unsigned long		*seq_zones_bitmap;
521 	unsigned long		*seq_zones_wlock;
522 #endif /* CONFIG_BLK_DEV_ZONED */
523 
524 	/*
525 	 * sg stuff
526 	 */
527 	unsigned int		sg_timeout;
528 	unsigned int		sg_reserved_size;
529 	int			node;
530 #ifdef CONFIG_BLK_DEV_IO_TRACE
531 	struct blk_trace	*blk_trace;
532 	struct mutex		blk_trace_mutex;
533 #endif
534 	/*
535 	 * for flush operations
536 	 */
537 	struct blk_flush_queue	*fq;
538 
539 	struct list_head	requeue_list;
540 	spinlock_t		requeue_lock;
541 	struct delayed_work	requeue_work;
542 
543 	struct mutex		sysfs_lock;
544 	struct mutex		sysfs_dir_lock;
545 
546 	/*
547 	 * for reusing dead hctx instance in case of updating
548 	 * nr_hw_queues
549 	 */
550 	struct list_head	unused_hctx_list;
551 	spinlock_t		unused_hctx_lock;
552 
553 	int			mq_freeze_depth;
554 
555 #if defined(CONFIG_BLK_DEV_BSG)
556 	struct bsg_class_device bsg_dev;
557 #endif
558 
559 #ifdef CONFIG_BLK_DEV_THROTTLING
560 	/* Throttle data */
561 	struct throtl_data *td;
562 #endif
563 	struct rcu_head		rcu_head;
564 	wait_queue_head_t	mq_freeze_wq;
565 	/*
566 	 * Protect concurrent access to q_usage_counter by
567 	 * percpu_ref_kill() and percpu_ref_reinit().
568 	 */
569 	struct mutex		mq_freeze_lock;
570 	struct percpu_ref	q_usage_counter;
571 
572 	struct blk_mq_tag_set	*tag_set;
573 	struct list_head	tag_set_list;
574 	struct bio_set		bio_split;
575 
576 #ifdef CONFIG_BLK_DEBUG_FS
577 	struct dentry		*debugfs_dir;
578 	struct dentry		*sched_debugfs_dir;
579 	struct dentry		*rqos_debugfs_dir;
580 #endif
581 
582 	bool			mq_sysfs_init_done;
583 
584 	size_t			cmd_size;
585 
586 	struct work_struct	release_work;
587 
588 #define BLK_MAX_WRITE_HINTS	5
589 	u64			write_hints[BLK_MAX_WRITE_HINTS];
590 };
591 
592 #define QUEUE_FLAG_STOPPED	0	/* queue is stopped */
593 #define QUEUE_FLAG_DYING	1	/* queue being torn down */
594 #define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
595 #define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
596 #define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
597 #define QUEUE_FLAG_NONROT	6	/* non-rotational device (SSD) */
598 #define QUEUE_FLAG_VIRT		QUEUE_FLAG_NONROT /* paravirt device */
599 #define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
600 #define QUEUE_FLAG_DISCARD	8	/* supports DISCARD */
601 #define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
602 #define QUEUE_FLAG_ADD_RANDOM	10	/* Contributes to random pool */
603 #define QUEUE_FLAG_SECERASE	11	/* supports secure erase */
604 #define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
605 #define QUEUE_FLAG_DEAD		13	/* queue tear-down finished */
606 #define QUEUE_FLAG_INIT_DONE	14	/* queue is initialized */
607 #define QUEUE_FLAG_POLL		16	/* IO polling enabled if set */
608 #define QUEUE_FLAG_WC		17	/* Write back caching */
609 #define QUEUE_FLAG_FUA		18	/* device supports FUA writes */
610 #define QUEUE_FLAG_DAX		19	/* device supports DAX */
611 #define QUEUE_FLAG_STATS	20	/* track IO start and completion times */
612 #define QUEUE_FLAG_POLL_STATS	21	/* collecting stats for hybrid polling */
613 #define QUEUE_FLAG_REGISTERED	22	/* queue has been registered to a disk */
614 #define QUEUE_FLAG_SCSI_PASSTHROUGH 23	/* queue supports SCSI commands */
615 #define QUEUE_FLAG_QUIESCED	24	/* queue has been quiesced */
616 #define QUEUE_FLAG_PCI_P2PDMA	25	/* device supports PCI p2p requests */
617 #define QUEUE_FLAG_ZONE_RESETALL 26	/* supports Zone Reset All */
618 #define QUEUE_FLAG_RQ_ALLOC_TIME 27	/* record rq->alloc_time_ns */
619 
620 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
621 				 (1 << QUEUE_FLAG_SAME_COMP))
622 
623 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
624 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
625 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
626 
627 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
628 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
629 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
630 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
631 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
632 #define blk_queue_noxmerges(q)	\
633 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
634 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
635 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
636 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
637 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
638 #define blk_queue_zone_resetall(q)	\
639 	test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
640 #define blk_queue_secure_erase(q) \
641 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
642 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
643 #define blk_queue_scsi_passthrough(q)	\
644 	test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
645 #define blk_queue_pci_p2pdma(q)	\
646 	test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
647 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
648 #define blk_queue_rq_alloc_time(q)	\
649 	test_bit(QUEUE_FLAG_RQ_ALLOC_TIME, &(q)->queue_flags)
650 #else
651 #define blk_queue_rq_alloc_time(q)	false
652 #endif
653 
654 #define blk_noretry_request(rq) \
655 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
656 			     REQ_FAILFAST_DRIVER))
657 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
658 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
659 #define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
660 #define blk_queue_registered(q)	test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
661 
662 extern void blk_set_pm_only(struct request_queue *q);
663 extern void blk_clear_pm_only(struct request_queue *q);
664 
665 static inline bool blk_account_rq(struct request *rq)
666 {
667 	return (rq->rq_flags & RQF_STARTED) && !blk_rq_is_passthrough(rq);
668 }
669 
670 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
671 
672 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
673 
674 #define rq_dma_dir(rq) \
675 	(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
676 
677 #define dma_map_bvec(dev, bv, dir, attrs) \
678 	dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
679 	(dir), (attrs))
680 
681 static inline bool queue_is_mq(struct request_queue *q)
682 {
683 	return q->mq_ops;
684 }
685 
686 static inline enum blk_zoned_model
687 blk_queue_zoned_model(struct request_queue *q)
688 {
689 	return q->limits.zoned;
690 }
691 
692 static inline bool blk_queue_is_zoned(struct request_queue *q)
693 {
694 	switch (blk_queue_zoned_model(q)) {
695 	case BLK_ZONED_HA:
696 	case BLK_ZONED_HM:
697 		return true;
698 	default:
699 		return false;
700 	}
701 }
702 
703 static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
704 {
705 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
706 }
707 
708 #ifdef CONFIG_BLK_DEV_ZONED
709 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
710 {
711 	return blk_queue_is_zoned(q) ? q->nr_zones : 0;
712 }
713 
714 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
715 					     sector_t sector)
716 {
717 	if (!blk_queue_is_zoned(q))
718 		return 0;
719 	return sector >> ilog2(q->limits.chunk_sectors);
720 }
721 
722 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
723 					 sector_t sector)
724 {
725 	if (!blk_queue_is_zoned(q) || !q->seq_zones_bitmap)
726 		return false;
727 	return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
728 }
729 #else /* CONFIG_BLK_DEV_ZONED */
730 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
731 {
732 	return 0;
733 }
734 #endif /* CONFIG_BLK_DEV_ZONED */
735 
736 static inline bool rq_is_sync(struct request *rq)
737 {
738 	return op_is_sync(rq->cmd_flags);
739 }
740 
741 static inline bool rq_mergeable(struct request *rq)
742 {
743 	if (blk_rq_is_passthrough(rq))
744 		return false;
745 
746 	if (req_op(rq) == REQ_OP_FLUSH)
747 		return false;
748 
749 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
750 		return false;
751 
752 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
753 		return false;
754 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
755 		return false;
756 
757 	return true;
758 }
759 
760 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
761 {
762 	if (bio_page(a) == bio_page(b) &&
763 	    bio_offset(a) == bio_offset(b))
764 		return true;
765 
766 	return false;
767 }
768 
769 static inline unsigned int blk_queue_depth(struct request_queue *q)
770 {
771 	if (q->queue_depth)
772 		return q->queue_depth;
773 
774 	return q->nr_requests;
775 }
776 
777 extern unsigned long blk_max_low_pfn, blk_max_pfn;
778 
779 /*
780  * standard bounce addresses:
781  *
782  * BLK_BOUNCE_HIGH	: bounce all highmem pages
783  * BLK_BOUNCE_ANY	: don't bounce anything
784  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
785  */
786 
787 #if BITS_PER_LONG == 32
788 #define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
789 #else
790 #define BLK_BOUNCE_HIGH		-1ULL
791 #endif
792 #define BLK_BOUNCE_ANY		(-1ULL)
793 #define BLK_BOUNCE_ISA		(DMA_BIT_MASK(24))
794 
795 /*
796  * default timeout for SG_IO if none specified
797  */
798 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
799 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
800 
801 struct rq_map_data {
802 	struct page **pages;
803 	int page_order;
804 	int nr_entries;
805 	unsigned long offset;
806 	int null_mapped;
807 	int from_user;
808 };
809 
810 struct req_iterator {
811 	struct bvec_iter iter;
812 	struct bio *bio;
813 };
814 
815 /* This should not be used directly - use rq_for_each_segment */
816 #define for_each_bio(_bio)		\
817 	for (; _bio; _bio = _bio->bi_next)
818 #define __rq_for_each_bio(_bio, rq)	\
819 	if ((rq->bio))			\
820 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
821 
822 #define rq_for_each_segment(bvl, _rq, _iter)			\
823 	__rq_for_each_bio(_iter.bio, _rq)			\
824 		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
825 
826 #define rq_for_each_bvec(bvl, _rq, _iter)			\
827 	__rq_for_each_bio(_iter.bio, _rq)			\
828 		bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
829 
830 #define rq_iter_last(bvec, _iter)				\
831 		(_iter.bio->bi_next == NULL &&			\
832 		 bio_iter_last(bvec, _iter.iter))
833 
834 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
835 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
836 #endif
837 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
838 extern void rq_flush_dcache_pages(struct request *rq);
839 #else
840 static inline void rq_flush_dcache_pages(struct request *rq)
841 {
842 }
843 #endif
844 
845 extern int blk_register_queue(struct gendisk *disk);
846 extern void blk_unregister_queue(struct gendisk *disk);
847 extern blk_qc_t generic_make_request(struct bio *bio);
848 extern blk_qc_t direct_make_request(struct bio *bio);
849 extern void blk_rq_init(struct request_queue *q, struct request *rq);
850 extern void blk_put_request(struct request *);
851 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
852 				       blk_mq_req_flags_t flags);
853 extern int blk_lld_busy(struct request_queue *q);
854 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
855 			     struct bio_set *bs, gfp_t gfp_mask,
856 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
857 			     void *data);
858 extern void blk_rq_unprep_clone(struct request *rq);
859 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
860 				     struct request *rq);
861 extern int blk_rq_append_bio(struct request *rq, struct bio **bio);
862 extern void blk_queue_split(struct request_queue *, struct bio **);
863 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
864 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
865 			      unsigned int, void __user *);
866 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
867 			  unsigned int, void __user *);
868 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
869 			 struct scsi_ioctl_command __user *);
870 
871 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
872 extern void blk_queue_exit(struct request_queue *q);
873 extern void blk_sync_queue(struct request_queue *q);
874 extern int blk_rq_map_user(struct request_queue *, struct request *,
875 			   struct rq_map_data *, void __user *, unsigned long,
876 			   gfp_t);
877 extern int blk_rq_unmap_user(struct bio *);
878 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
879 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
880 			       struct rq_map_data *, const struct iov_iter *,
881 			       gfp_t);
882 extern void blk_execute_rq(struct request_queue *, struct gendisk *,
883 			  struct request *, int);
884 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
885 				  struct request *, int, rq_end_io_fn *);
886 
887 /* Helper to convert REQ_OP_XXX to its string format XXX */
888 extern const char *blk_op_str(unsigned int op);
889 
890 int blk_status_to_errno(blk_status_t status);
891 blk_status_t errno_to_blk_status(int errno);
892 
893 int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin);
894 
895 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
896 {
897 	return bdev->bd_disk->queue;	/* this is never NULL */
898 }
899 
900 /*
901  * The basic unit of block I/O is a sector. It is used in a number of contexts
902  * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
903  * bytes. Variables of type sector_t represent an offset or size that is a
904  * multiple of 512 bytes. Hence these two constants.
905  */
906 #ifndef SECTOR_SHIFT
907 #define SECTOR_SHIFT 9
908 #endif
909 #ifndef SECTOR_SIZE
910 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
911 #endif
912 
913 /*
914  * blk_rq_pos()			: the current sector
915  * blk_rq_bytes()		: bytes left in the entire request
916  * blk_rq_cur_bytes()		: bytes left in the current segment
917  * blk_rq_err_bytes()		: bytes left till the next error boundary
918  * blk_rq_sectors()		: sectors left in the entire request
919  * blk_rq_cur_sectors()		: sectors left in the current segment
920  */
921 static inline sector_t blk_rq_pos(const struct request *rq)
922 {
923 	return rq->__sector;
924 }
925 
926 static inline unsigned int blk_rq_bytes(const struct request *rq)
927 {
928 	return rq->__data_len;
929 }
930 
931 static inline int blk_rq_cur_bytes(const struct request *rq)
932 {
933 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
934 }
935 
936 extern unsigned int blk_rq_err_bytes(const struct request *rq);
937 
938 static inline unsigned int blk_rq_sectors(const struct request *rq)
939 {
940 	return blk_rq_bytes(rq) >> SECTOR_SHIFT;
941 }
942 
943 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
944 {
945 	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
946 }
947 
948 #ifdef CONFIG_BLK_DEV_ZONED
949 static inline unsigned int blk_rq_zone_no(struct request *rq)
950 {
951 	return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
952 }
953 
954 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
955 {
956 	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
957 }
958 #endif /* CONFIG_BLK_DEV_ZONED */
959 
960 /*
961  * Some commands like WRITE SAME have a payload or data transfer size which
962  * is different from the size of the request.  Any driver that supports such
963  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
964  * calculate the data transfer size.
965  */
966 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
967 {
968 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
969 		return rq->special_vec.bv_len;
970 	return blk_rq_bytes(rq);
971 }
972 
973 /*
974  * Return the first full biovec in the request.  The caller needs to check that
975  * there are any bvecs before calling this helper.
976  */
977 static inline struct bio_vec req_bvec(struct request *rq)
978 {
979 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
980 		return rq->special_vec;
981 	return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
982 }
983 
984 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
985 						     int op)
986 {
987 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
988 		return min(q->limits.max_discard_sectors,
989 			   UINT_MAX >> SECTOR_SHIFT);
990 
991 	if (unlikely(op == REQ_OP_WRITE_SAME))
992 		return q->limits.max_write_same_sectors;
993 
994 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
995 		return q->limits.max_write_zeroes_sectors;
996 
997 	return q->limits.max_sectors;
998 }
999 
1000 /*
1001  * Return maximum size of a request at given offset. Only valid for
1002  * file system requests.
1003  */
1004 static inline unsigned int blk_max_size_offset(struct request_queue *q,
1005 					       sector_t offset)
1006 {
1007 	if (!q->limits.chunk_sectors)
1008 		return q->limits.max_sectors;
1009 
1010 	return min(q->limits.max_sectors, (unsigned int)(q->limits.chunk_sectors -
1011 			(offset & (q->limits.chunk_sectors - 1))));
1012 }
1013 
1014 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
1015 						  sector_t offset)
1016 {
1017 	struct request_queue *q = rq->q;
1018 
1019 	if (blk_rq_is_passthrough(rq))
1020 		return q->limits.max_hw_sectors;
1021 
1022 	if (!q->limits.chunk_sectors ||
1023 	    req_op(rq) == REQ_OP_DISCARD ||
1024 	    req_op(rq) == REQ_OP_SECURE_ERASE)
1025 		return blk_queue_get_max_sectors(q, req_op(rq));
1026 
1027 	return min(blk_max_size_offset(q, offset),
1028 			blk_queue_get_max_sectors(q, req_op(rq)));
1029 }
1030 
1031 static inline unsigned int blk_rq_count_bios(struct request *rq)
1032 {
1033 	unsigned int nr_bios = 0;
1034 	struct bio *bio;
1035 
1036 	__rq_for_each_bio(bio, rq)
1037 		nr_bios++;
1038 
1039 	return nr_bios;
1040 }
1041 
1042 void blk_steal_bios(struct bio_list *list, struct request *rq);
1043 
1044 /*
1045  * Request completion related functions.
1046  *
1047  * blk_update_request() completes given number of bytes and updates
1048  * the request without completing it.
1049  */
1050 extern bool blk_update_request(struct request *rq, blk_status_t error,
1051 			       unsigned int nr_bytes);
1052 
1053 extern void __blk_complete_request(struct request *);
1054 extern void blk_abort_request(struct request *);
1055 
1056 /*
1057  * Access functions for manipulating queue properties
1058  */
1059 extern void blk_cleanup_queue(struct request_queue *);
1060 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1061 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1062 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1063 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1064 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1065 extern void blk_queue_max_discard_segments(struct request_queue *,
1066 		unsigned short);
1067 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1068 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1069 		unsigned int max_discard_sectors);
1070 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1071 		unsigned int max_write_same_sectors);
1072 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1073 		unsigned int max_write_same_sectors);
1074 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
1075 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1076 extern void blk_queue_alignment_offset(struct request_queue *q,
1077 				       unsigned int alignment);
1078 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1079 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1080 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1081 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1082 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1083 extern void blk_set_default_limits(struct queue_limits *lim);
1084 extern void blk_set_stacking_limits(struct queue_limits *lim);
1085 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1086 			    sector_t offset);
1087 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1088 			    sector_t offset);
1089 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1090 			      sector_t offset);
1091 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1092 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1093 extern int blk_queue_dma_drain(struct request_queue *q,
1094 			       dma_drain_needed_fn *dma_drain_needed,
1095 			       void *buf, unsigned int size);
1096 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1097 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1098 extern void blk_queue_dma_alignment(struct request_queue *, int);
1099 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1100 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1101 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1102 extern void blk_queue_required_elevator_features(struct request_queue *q,
1103 						 unsigned int features);
1104 
1105 /*
1106  * Number of physical segments as sent to the device.
1107  *
1108  * Normally this is the number of discontiguous data segments sent by the
1109  * submitter.  But for data-less command like discard we might have no
1110  * actual data segments submitted, but the driver might have to add it's
1111  * own special payload.  In that case we still return 1 here so that this
1112  * special payload will be mapped.
1113  */
1114 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1115 {
1116 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1117 		return 1;
1118 	return rq->nr_phys_segments;
1119 }
1120 
1121 /*
1122  * Number of discard segments (or ranges) the driver needs to fill in.
1123  * Each discard bio merged into a request is counted as one segment.
1124  */
1125 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1126 {
1127 	return max_t(unsigned short, rq->nr_phys_segments, 1);
1128 }
1129 
1130 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1131 extern void blk_dump_rq_flags(struct request *, char *);
1132 extern long nr_blockdev_pages(void);
1133 
1134 bool __must_check blk_get_queue(struct request_queue *);
1135 struct request_queue *blk_alloc_queue(gfp_t);
1136 struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id);
1137 extern void blk_put_queue(struct request_queue *);
1138 extern void blk_set_queue_dying(struct request_queue *);
1139 
1140 /*
1141  * blk_plug permits building a queue of related requests by holding the I/O
1142  * fragments for a short period. This allows merging of sequential requests
1143  * into single larger request. As the requests are moved from a per-task list to
1144  * the device's request_queue in a batch, this results in improved scalability
1145  * as the lock contention for request_queue lock is reduced.
1146  *
1147  * It is ok not to disable preemption when adding the request to the plug list
1148  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1149  * the plug list when the task sleeps by itself. For details, please see
1150  * schedule() where blk_schedule_flush_plug() is called.
1151  */
1152 struct blk_plug {
1153 	struct list_head mq_list; /* blk-mq requests */
1154 	struct list_head cb_list; /* md requires an unplug callback */
1155 	unsigned short rq_count;
1156 	bool multiple_queues;
1157 };
1158 #define BLK_MAX_REQUEST_COUNT 16
1159 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1160 
1161 struct blk_plug_cb;
1162 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1163 struct blk_plug_cb {
1164 	struct list_head list;
1165 	blk_plug_cb_fn callback;
1166 	void *data;
1167 };
1168 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1169 					     void *data, int size);
1170 extern void blk_start_plug(struct blk_plug *);
1171 extern void blk_finish_plug(struct blk_plug *);
1172 extern void blk_flush_plug_list(struct blk_plug *, bool);
1173 
1174 static inline void blk_flush_plug(struct task_struct *tsk)
1175 {
1176 	struct blk_plug *plug = tsk->plug;
1177 
1178 	if (plug)
1179 		blk_flush_plug_list(plug, false);
1180 }
1181 
1182 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1183 {
1184 	struct blk_plug *plug = tsk->plug;
1185 
1186 	if (plug)
1187 		blk_flush_plug_list(plug, true);
1188 }
1189 
1190 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1191 {
1192 	struct blk_plug *plug = tsk->plug;
1193 
1194 	return plug &&
1195 		 (!list_empty(&plug->mq_list) ||
1196 		 !list_empty(&plug->cb_list));
1197 }
1198 
1199 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1200 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1201 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1202 
1203 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
1204 
1205 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1206 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1207 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1208 		sector_t nr_sects, gfp_t gfp_mask, int flags,
1209 		struct bio **biop);
1210 
1211 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
1212 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
1213 
1214 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1215 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1216 		unsigned flags);
1217 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1218 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1219 
1220 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1221 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1222 {
1223 	return blkdev_issue_discard(sb->s_bdev,
1224 				    block << (sb->s_blocksize_bits -
1225 					      SECTOR_SHIFT),
1226 				    nr_blocks << (sb->s_blocksize_bits -
1227 						  SECTOR_SHIFT),
1228 				    gfp_mask, flags);
1229 }
1230 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1231 		sector_t nr_blocks, gfp_t gfp_mask)
1232 {
1233 	return blkdev_issue_zeroout(sb->s_bdev,
1234 				    block << (sb->s_blocksize_bits -
1235 					      SECTOR_SHIFT),
1236 				    nr_blocks << (sb->s_blocksize_bits -
1237 						  SECTOR_SHIFT),
1238 				    gfp_mask, 0);
1239 }
1240 
1241 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1242 
1243 enum blk_default_limits {
1244 	BLK_MAX_SEGMENTS	= 128,
1245 	BLK_SAFE_MAX_SECTORS	= 255,
1246 	BLK_DEF_MAX_SECTORS	= 2560,
1247 	BLK_MAX_SEGMENT_SIZE	= 65536,
1248 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
1249 };
1250 
1251 static inline unsigned long queue_segment_boundary(const struct request_queue *q)
1252 {
1253 	return q->limits.seg_boundary_mask;
1254 }
1255 
1256 static inline unsigned long queue_virt_boundary(const struct request_queue *q)
1257 {
1258 	return q->limits.virt_boundary_mask;
1259 }
1260 
1261 static inline unsigned int queue_max_sectors(const struct request_queue *q)
1262 {
1263 	return q->limits.max_sectors;
1264 }
1265 
1266 static inline unsigned int queue_max_hw_sectors(const struct request_queue *q)
1267 {
1268 	return q->limits.max_hw_sectors;
1269 }
1270 
1271 static inline unsigned short queue_max_segments(const struct request_queue *q)
1272 {
1273 	return q->limits.max_segments;
1274 }
1275 
1276 static inline unsigned short queue_max_discard_segments(const struct request_queue *q)
1277 {
1278 	return q->limits.max_discard_segments;
1279 }
1280 
1281 static inline unsigned int queue_max_segment_size(const struct request_queue *q)
1282 {
1283 	return q->limits.max_segment_size;
1284 }
1285 
1286 static inline unsigned short queue_logical_block_size(const struct request_queue *q)
1287 {
1288 	int retval = 512;
1289 
1290 	if (q && q->limits.logical_block_size)
1291 		retval = q->limits.logical_block_size;
1292 
1293 	return retval;
1294 }
1295 
1296 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1297 {
1298 	return queue_logical_block_size(bdev_get_queue(bdev));
1299 }
1300 
1301 static inline unsigned int queue_physical_block_size(const struct request_queue *q)
1302 {
1303 	return q->limits.physical_block_size;
1304 }
1305 
1306 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1307 {
1308 	return queue_physical_block_size(bdev_get_queue(bdev));
1309 }
1310 
1311 static inline unsigned int queue_io_min(const struct request_queue *q)
1312 {
1313 	return q->limits.io_min;
1314 }
1315 
1316 static inline int bdev_io_min(struct block_device *bdev)
1317 {
1318 	return queue_io_min(bdev_get_queue(bdev));
1319 }
1320 
1321 static inline unsigned int queue_io_opt(const struct request_queue *q)
1322 {
1323 	return q->limits.io_opt;
1324 }
1325 
1326 static inline int bdev_io_opt(struct block_device *bdev)
1327 {
1328 	return queue_io_opt(bdev_get_queue(bdev));
1329 }
1330 
1331 static inline int queue_alignment_offset(const struct request_queue *q)
1332 {
1333 	if (q->limits.misaligned)
1334 		return -1;
1335 
1336 	return q->limits.alignment_offset;
1337 }
1338 
1339 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1340 {
1341 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1342 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1343 		<< SECTOR_SHIFT;
1344 
1345 	return (granularity + lim->alignment_offset - alignment) % granularity;
1346 }
1347 
1348 static inline int bdev_alignment_offset(struct block_device *bdev)
1349 {
1350 	struct request_queue *q = bdev_get_queue(bdev);
1351 
1352 	if (q->limits.misaligned)
1353 		return -1;
1354 
1355 	if (bdev != bdev->bd_contains)
1356 		return bdev->bd_part->alignment_offset;
1357 
1358 	return q->limits.alignment_offset;
1359 }
1360 
1361 static inline int queue_discard_alignment(const struct request_queue *q)
1362 {
1363 	if (q->limits.discard_misaligned)
1364 		return -1;
1365 
1366 	return q->limits.discard_alignment;
1367 }
1368 
1369 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1370 {
1371 	unsigned int alignment, granularity, offset;
1372 
1373 	if (!lim->max_discard_sectors)
1374 		return 0;
1375 
1376 	/* Why are these in bytes, not sectors? */
1377 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
1378 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
1379 	if (!granularity)
1380 		return 0;
1381 
1382 	/* Offset of the partition start in 'granularity' sectors */
1383 	offset = sector_div(sector, granularity);
1384 
1385 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
1386 	offset = (granularity + alignment - offset) % granularity;
1387 
1388 	/* Turn it back into bytes, gaah */
1389 	return offset << SECTOR_SHIFT;
1390 }
1391 
1392 static inline int bdev_discard_alignment(struct block_device *bdev)
1393 {
1394 	struct request_queue *q = bdev_get_queue(bdev);
1395 
1396 	if (bdev != bdev->bd_contains)
1397 		return bdev->bd_part->discard_alignment;
1398 
1399 	return q->limits.discard_alignment;
1400 }
1401 
1402 static inline unsigned int bdev_write_same(struct block_device *bdev)
1403 {
1404 	struct request_queue *q = bdev_get_queue(bdev);
1405 
1406 	if (q)
1407 		return q->limits.max_write_same_sectors;
1408 
1409 	return 0;
1410 }
1411 
1412 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1413 {
1414 	struct request_queue *q = bdev_get_queue(bdev);
1415 
1416 	if (q)
1417 		return q->limits.max_write_zeroes_sectors;
1418 
1419 	return 0;
1420 }
1421 
1422 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1423 {
1424 	struct request_queue *q = bdev_get_queue(bdev);
1425 
1426 	if (q)
1427 		return blk_queue_zoned_model(q);
1428 
1429 	return BLK_ZONED_NONE;
1430 }
1431 
1432 static inline bool bdev_is_zoned(struct block_device *bdev)
1433 {
1434 	struct request_queue *q = bdev_get_queue(bdev);
1435 
1436 	if (q)
1437 		return blk_queue_is_zoned(q);
1438 
1439 	return false;
1440 }
1441 
1442 static inline sector_t bdev_zone_sectors(struct block_device *bdev)
1443 {
1444 	struct request_queue *q = bdev_get_queue(bdev);
1445 
1446 	if (q)
1447 		return blk_queue_zone_sectors(q);
1448 	return 0;
1449 }
1450 
1451 static inline int queue_dma_alignment(const struct request_queue *q)
1452 {
1453 	return q ? q->dma_alignment : 511;
1454 }
1455 
1456 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1457 				 unsigned int len)
1458 {
1459 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1460 	return !(addr & alignment) && !(len & alignment);
1461 }
1462 
1463 /* assumes size > 256 */
1464 static inline unsigned int blksize_bits(unsigned int size)
1465 {
1466 	unsigned int bits = 8;
1467 	do {
1468 		bits++;
1469 		size >>= 1;
1470 	} while (size > 256);
1471 	return bits;
1472 }
1473 
1474 static inline unsigned int block_size(struct block_device *bdev)
1475 {
1476 	return bdev->bd_block_size;
1477 }
1478 
1479 typedef struct {struct page *v;} Sector;
1480 
1481 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1482 
1483 static inline void put_dev_sector(Sector p)
1484 {
1485 	put_page(p.v);
1486 }
1487 
1488 int kblockd_schedule_work(struct work_struct *work);
1489 int kblockd_schedule_work_on(int cpu, struct work_struct *work);
1490 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1491 
1492 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1493 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1494 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1495 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1496 
1497 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1498 
1499 enum blk_integrity_flags {
1500 	BLK_INTEGRITY_VERIFY		= 1 << 0,
1501 	BLK_INTEGRITY_GENERATE		= 1 << 1,
1502 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
1503 	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
1504 };
1505 
1506 struct blk_integrity_iter {
1507 	void			*prot_buf;
1508 	void			*data_buf;
1509 	sector_t		seed;
1510 	unsigned int		data_size;
1511 	unsigned short		interval;
1512 	const char		*disk_name;
1513 };
1514 
1515 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1516 
1517 struct blk_integrity_profile {
1518 	integrity_processing_fn		*generate_fn;
1519 	integrity_processing_fn		*verify_fn;
1520 	const char			*name;
1521 };
1522 
1523 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1524 extern void blk_integrity_unregister(struct gendisk *);
1525 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1526 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1527 				   struct scatterlist *);
1528 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1529 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1530 				   struct request *);
1531 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1532 				    struct bio *);
1533 
1534 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1535 {
1536 	struct blk_integrity *bi = &disk->queue->integrity;
1537 
1538 	if (!bi->profile)
1539 		return NULL;
1540 
1541 	return bi;
1542 }
1543 
1544 static inline
1545 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1546 {
1547 	return blk_get_integrity(bdev->bd_disk);
1548 }
1549 
1550 static inline bool blk_integrity_rq(struct request *rq)
1551 {
1552 	return rq->cmd_flags & REQ_INTEGRITY;
1553 }
1554 
1555 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1556 						    unsigned int segs)
1557 {
1558 	q->limits.max_integrity_segments = segs;
1559 }
1560 
1561 static inline unsigned short
1562 queue_max_integrity_segments(const struct request_queue *q)
1563 {
1564 	return q->limits.max_integrity_segments;
1565 }
1566 
1567 /**
1568  * bio_integrity_intervals - Return number of integrity intervals for a bio
1569  * @bi:		blk_integrity profile for device
1570  * @sectors:	Size of the bio in 512-byte sectors
1571  *
1572  * Description: The block layer calculates everything in 512 byte
1573  * sectors but integrity metadata is done in terms of the data integrity
1574  * interval size of the storage device.  Convert the block layer sectors
1575  * to the appropriate number of integrity intervals.
1576  */
1577 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1578 						   unsigned int sectors)
1579 {
1580 	return sectors >> (bi->interval_exp - 9);
1581 }
1582 
1583 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1584 					       unsigned int sectors)
1585 {
1586 	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
1587 }
1588 
1589 /*
1590  * Return the first bvec that contains integrity data.  Only drivers that are
1591  * limited to a single integrity segment should use this helper.
1592  */
1593 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1594 {
1595 	if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
1596 		return NULL;
1597 	return rq->bio->bi_integrity->bip_vec;
1598 }
1599 
1600 #else /* CONFIG_BLK_DEV_INTEGRITY */
1601 
1602 struct bio;
1603 struct block_device;
1604 struct gendisk;
1605 struct blk_integrity;
1606 
1607 static inline int blk_integrity_rq(struct request *rq)
1608 {
1609 	return 0;
1610 }
1611 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1612 					    struct bio *b)
1613 {
1614 	return 0;
1615 }
1616 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1617 					  struct bio *b,
1618 					  struct scatterlist *s)
1619 {
1620 	return 0;
1621 }
1622 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1623 {
1624 	return NULL;
1625 }
1626 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1627 {
1628 	return NULL;
1629 }
1630 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1631 {
1632 	return 0;
1633 }
1634 static inline void blk_integrity_register(struct gendisk *d,
1635 					 struct blk_integrity *b)
1636 {
1637 }
1638 static inline void blk_integrity_unregister(struct gendisk *d)
1639 {
1640 }
1641 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1642 						    unsigned int segs)
1643 {
1644 }
1645 static inline unsigned short queue_max_integrity_segments(const struct request_queue *q)
1646 {
1647 	return 0;
1648 }
1649 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1650 					  struct request *r1,
1651 					  struct request *r2)
1652 {
1653 	return true;
1654 }
1655 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1656 					   struct request *r,
1657 					   struct bio *b)
1658 {
1659 	return true;
1660 }
1661 
1662 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1663 						   unsigned int sectors)
1664 {
1665 	return 0;
1666 }
1667 
1668 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1669 					       unsigned int sectors)
1670 {
1671 	return 0;
1672 }
1673 
1674 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1675 {
1676 	return NULL;
1677 }
1678 
1679 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1680 
1681 struct block_device_operations {
1682 	int (*open) (struct block_device *, fmode_t);
1683 	void (*release) (struct gendisk *, fmode_t);
1684 	int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
1685 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1686 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1687 	unsigned int (*check_events) (struct gendisk *disk,
1688 				      unsigned int clearing);
1689 	/* ->media_changed() is DEPRECATED, use ->check_events() instead */
1690 	int (*media_changed) (struct gendisk *);
1691 	void (*unlock_native_capacity) (struct gendisk *);
1692 	int (*revalidate_disk) (struct gendisk *);
1693 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1694 	/* this callback is with swap_lock and sometimes page table lock held */
1695 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1696 	int (*report_zones)(struct gendisk *, sector_t sector,
1697 			    struct blk_zone *zones, unsigned int *nr_zones);
1698 	struct module *owner;
1699 	const struct pr_ops *pr_ops;
1700 };
1701 
1702 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1703 				 unsigned long);
1704 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1705 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1706 						struct writeback_control *);
1707 
1708 #ifdef CONFIG_BLK_DEV_ZONED
1709 bool blk_req_needs_zone_write_lock(struct request *rq);
1710 void __blk_req_zone_write_lock(struct request *rq);
1711 void __blk_req_zone_write_unlock(struct request *rq);
1712 
1713 static inline void blk_req_zone_write_lock(struct request *rq)
1714 {
1715 	if (blk_req_needs_zone_write_lock(rq))
1716 		__blk_req_zone_write_lock(rq);
1717 }
1718 
1719 static inline void blk_req_zone_write_unlock(struct request *rq)
1720 {
1721 	if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
1722 		__blk_req_zone_write_unlock(rq);
1723 }
1724 
1725 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1726 {
1727 	return rq->q->seq_zones_wlock &&
1728 		test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
1729 }
1730 
1731 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1732 {
1733 	if (!blk_req_needs_zone_write_lock(rq))
1734 		return true;
1735 	return !blk_req_zone_is_write_locked(rq);
1736 }
1737 #else
1738 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
1739 {
1740 	return false;
1741 }
1742 
1743 static inline void blk_req_zone_write_lock(struct request *rq)
1744 {
1745 }
1746 
1747 static inline void blk_req_zone_write_unlock(struct request *rq)
1748 {
1749 }
1750 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1751 {
1752 	return false;
1753 }
1754 
1755 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1756 {
1757 	return true;
1758 }
1759 #endif /* CONFIG_BLK_DEV_ZONED */
1760 
1761 #else /* CONFIG_BLOCK */
1762 
1763 struct block_device;
1764 
1765 /*
1766  * stubs for when the block layer is configured out
1767  */
1768 #define buffer_heads_over_limit 0
1769 
1770 static inline long nr_blockdev_pages(void)
1771 {
1772 	return 0;
1773 }
1774 
1775 struct blk_plug {
1776 };
1777 
1778 static inline void blk_start_plug(struct blk_plug *plug)
1779 {
1780 }
1781 
1782 static inline void blk_finish_plug(struct blk_plug *plug)
1783 {
1784 }
1785 
1786 static inline void blk_flush_plug(struct task_struct *task)
1787 {
1788 }
1789 
1790 static inline void blk_schedule_flush_plug(struct task_struct *task)
1791 {
1792 }
1793 
1794 
1795 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1796 {
1797 	return false;
1798 }
1799 
1800 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1801 				     sector_t *error_sector)
1802 {
1803 	return 0;
1804 }
1805 
1806 #endif /* CONFIG_BLOCK */
1807 
1808 static inline void blk_wake_io_task(struct task_struct *waiter)
1809 {
1810 	/*
1811 	 * If we're polling, the task itself is doing the completions. For
1812 	 * that case, we don't need to signal a wakeup, it's enough to just
1813 	 * mark us as RUNNING.
1814 	 */
1815 	if (waiter == current)
1816 		__set_current_state(TASK_RUNNING);
1817 	else
1818 		wake_up_process(waiter);
1819 }
1820 
1821 #endif
1822