xref: /linux-6.15/include/linux/blkdev.h (revision 4e74eeb2)
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 struct blk_keyslot_manager;
47 
48 #define BLKDEV_MIN_RQ	4
49 #define BLKDEV_MAX_RQ	128	/* Default maximum */
50 
51 /* Must be consistent with blk_mq_poll_stats_bkt() */
52 #define BLK_MQ_POLL_STATS_BKTS 16
53 
54 /* Doing classic polling */
55 #define BLK_MQ_POLL_CLASSIC -1
56 
57 /*
58  * Maximum number of blkcg policies allowed to be registered concurrently.
59  * Defined here to simplify include dependency.
60  */
61 #define BLKCG_MAX_POLS		5
62 
63 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
64 
65 /*
66  * request flags */
67 typedef __u32 __bitwise req_flags_t;
68 
69 /* elevator knows about this request */
70 #define RQF_SORTED		((__force req_flags_t)(1 << 0))
71 /* drive already may have started this one */
72 #define RQF_STARTED		((__force req_flags_t)(1 << 1))
73 /* may not be passed by ioscheduler */
74 #define RQF_SOFTBARRIER		((__force req_flags_t)(1 << 3))
75 /* request for flush sequence */
76 #define RQF_FLUSH_SEQ		((__force req_flags_t)(1 << 4))
77 /* merge of different types, fail separately */
78 #define RQF_MIXED_MERGE		((__force req_flags_t)(1 << 5))
79 /* track inflight for MQ */
80 #define RQF_MQ_INFLIGHT		((__force req_flags_t)(1 << 6))
81 /* don't call prep for this one */
82 #define RQF_DONTPREP		((__force req_flags_t)(1 << 7))
83 /* set for "ide_preempt" requests and also for requests for which the SCSI
84    "quiesce" state must be ignored. */
85 #define RQF_PREEMPT		((__force req_flags_t)(1 << 8))
86 /* vaguely specified driver internal error.  Ignored by the block layer */
87 #define RQF_FAILED		((__force req_flags_t)(1 << 10))
88 /* don't warn about errors */
89 #define RQF_QUIET		((__force req_flags_t)(1 << 11))
90 /* elevator private data attached */
91 #define RQF_ELVPRIV		((__force req_flags_t)(1 << 12))
92 /* account into disk and partition IO statistics */
93 #define RQF_IO_STAT		((__force req_flags_t)(1 << 13))
94 /* request came from our alloc pool */
95 #define RQF_ALLOCED		((__force req_flags_t)(1 << 14))
96 /* runtime pm request */
97 #define RQF_PM			((__force req_flags_t)(1 << 15))
98 /* on IO scheduler merge hash */
99 #define RQF_HASHED		((__force req_flags_t)(1 << 16))
100 /* track IO completion time */
101 #define RQF_STATS		((__force req_flags_t)(1 << 17))
102 /* Look at ->special_vec for the actual data payload instead of the
103    bio chain. */
104 #define RQF_SPECIAL_PAYLOAD	((__force req_flags_t)(1 << 18))
105 /* The per-zone write lock is held for this request */
106 #define RQF_ZONE_WRITE_LOCKED	((__force req_flags_t)(1 << 19))
107 /* already slept for hybrid poll */
108 #define RQF_MQ_POLL_SLEPT	((__force req_flags_t)(1 << 20))
109 /* ->timeout has been called, don't expire again */
110 #define RQF_TIMED_OUT		((__force req_flags_t)(1 << 21))
111 
112 /* flags that prevent us from merging requests: */
113 #define RQF_NOMERGE_FLAGS \
114 	(RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
115 
116 /*
117  * Request state for blk-mq.
118  */
119 enum mq_rq_state {
120 	MQ_RQ_IDLE		= 0,
121 	MQ_RQ_IN_FLIGHT		= 1,
122 	MQ_RQ_COMPLETE		= 2,
123 };
124 
125 /*
126  * Try to put the fields that are referenced together in the same cacheline.
127  *
128  * If you modify this structure, make sure to update blk_rq_init() and
129  * especially blk_mq_rq_ctx_init() to take care of the added fields.
130  */
131 struct request {
132 	struct request_queue *q;
133 	struct blk_mq_ctx *mq_ctx;
134 	struct blk_mq_hw_ctx *mq_hctx;
135 
136 	unsigned int cmd_flags;		/* op and common flags */
137 	req_flags_t rq_flags;
138 
139 	int tag;
140 	int internal_tag;
141 
142 	/* the following two fields are internal, NEVER access directly */
143 	unsigned int __data_len;	/* total data len */
144 	sector_t __sector;		/* sector cursor */
145 
146 	struct bio *bio;
147 	struct bio *biotail;
148 
149 	struct list_head queuelist;
150 
151 	/*
152 	 * The hash is used inside the scheduler, and killed once the
153 	 * request reaches the dispatch list. The ipi_list is only used
154 	 * to queue the request for softirq completion, which is long
155 	 * after the request has been unhashed (and even removed from
156 	 * the dispatch list).
157 	 */
158 	union {
159 		struct hlist_node hash;	/* merge hash */
160 		struct list_head ipi_list;
161 	};
162 
163 	/*
164 	 * The rb_node is only used inside the io scheduler, requests
165 	 * are pruned when moved to the dispatch queue. So let the
166 	 * completion_data share space with the rb_node.
167 	 */
168 	union {
169 		struct rb_node rb_node;	/* sort/lookup */
170 		struct bio_vec special_vec;
171 		void *completion_data;
172 		int error_count; /* for legacy drivers, don't use */
173 	};
174 
175 	/*
176 	 * Three pointers are available for the IO schedulers, if they need
177 	 * more they have to dynamically allocate it.  Flush requests are
178 	 * never put on the IO scheduler. So let the flush fields share
179 	 * space with the elevator data.
180 	 */
181 	union {
182 		struct {
183 			struct io_cq		*icq;
184 			void			*priv[2];
185 		} elv;
186 
187 		struct {
188 			unsigned int		seq;
189 			struct list_head	list;
190 			rq_end_io_fn		*saved_end_io;
191 		} flush;
192 	};
193 
194 	struct gendisk *rq_disk;
195 	struct hd_struct *part;
196 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
197 	/* Time that the first bio started allocating this request. */
198 	u64 alloc_time_ns;
199 #endif
200 	/* Time that this request was allocated for this IO. */
201 	u64 start_time_ns;
202 	/* Time that I/O was submitted to the device. */
203 	u64 io_start_time_ns;
204 
205 #ifdef CONFIG_BLK_WBT
206 	unsigned short wbt_flags;
207 #endif
208 	/*
209 	 * rq sectors used for blk stats. It has the same value
210 	 * with blk_rq_sectors(rq), except that it never be zeroed
211 	 * by completion.
212 	 */
213 	unsigned short stats_sectors;
214 
215 	/*
216 	 * Number of scatter-gather DMA addr+len pairs after
217 	 * physical address coalescing is performed.
218 	 */
219 	unsigned short nr_phys_segments;
220 
221 #if defined(CONFIG_BLK_DEV_INTEGRITY)
222 	unsigned short nr_integrity_segments;
223 #endif
224 
225 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
226 	struct bio_crypt_ctx *crypt_ctx;
227 	struct blk_ksm_keyslot *crypt_keyslot;
228 #endif
229 
230 	unsigned short write_hint;
231 	unsigned short ioprio;
232 
233 	enum mq_rq_state state;
234 	refcount_t ref;
235 
236 	unsigned int timeout;
237 	unsigned long deadline;
238 
239 	union {
240 		struct __call_single_data csd;
241 		u64 fifo_time;
242 	};
243 
244 	/*
245 	 * completion callback.
246 	 */
247 	rq_end_io_fn *end_io;
248 	void *end_io_data;
249 };
250 
251 static inline bool blk_op_is_scsi(unsigned int op)
252 {
253 	return op == REQ_OP_SCSI_IN || op == REQ_OP_SCSI_OUT;
254 }
255 
256 static inline bool blk_op_is_private(unsigned int op)
257 {
258 	return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT;
259 }
260 
261 static inline bool blk_rq_is_scsi(struct request *rq)
262 {
263 	return blk_op_is_scsi(req_op(rq));
264 }
265 
266 static inline bool blk_rq_is_private(struct request *rq)
267 {
268 	return blk_op_is_private(req_op(rq));
269 }
270 
271 static inline bool blk_rq_is_passthrough(struct request *rq)
272 {
273 	return blk_rq_is_scsi(rq) || blk_rq_is_private(rq);
274 }
275 
276 static inline bool bio_is_passthrough(struct bio *bio)
277 {
278 	unsigned op = bio_op(bio);
279 
280 	return blk_op_is_scsi(op) || blk_op_is_private(op);
281 }
282 
283 static inline unsigned short req_get_ioprio(struct request *req)
284 {
285 	return req->ioprio;
286 }
287 
288 #include <linux/elevator.h>
289 
290 struct blk_queue_ctx;
291 
292 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
293 
294 struct bio_vec;
295 
296 enum blk_eh_timer_return {
297 	BLK_EH_DONE,		/* drivers has completed the command */
298 	BLK_EH_RESET_TIMER,	/* reset timer and try again */
299 };
300 
301 enum blk_queue_state {
302 	Queue_down,
303 	Queue_up,
304 };
305 
306 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
307 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
308 
309 #define BLK_SCSI_MAX_CMDS	(256)
310 #define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
311 
312 /*
313  * Zoned block device models (zoned limit).
314  */
315 enum blk_zoned_model {
316 	BLK_ZONED_NONE,	/* Regular block device */
317 	BLK_ZONED_HA,	/* Host-aware zoned block device */
318 	BLK_ZONED_HM,	/* Host-managed zoned block device */
319 };
320 
321 struct queue_limits {
322 	unsigned long		bounce_pfn;
323 	unsigned long		seg_boundary_mask;
324 	unsigned long		virt_boundary_mask;
325 
326 	unsigned int		max_hw_sectors;
327 	unsigned int		max_dev_sectors;
328 	unsigned int		chunk_sectors;
329 	unsigned int		max_sectors;
330 	unsigned int		max_segment_size;
331 	unsigned int		physical_block_size;
332 	unsigned int		logical_block_size;
333 	unsigned int		alignment_offset;
334 	unsigned int		io_min;
335 	unsigned int		io_opt;
336 	unsigned int		max_discard_sectors;
337 	unsigned int		max_hw_discard_sectors;
338 	unsigned int		max_write_same_sectors;
339 	unsigned int		max_write_zeroes_sectors;
340 	unsigned int		max_zone_append_sectors;
341 	unsigned int		discard_granularity;
342 	unsigned int		discard_alignment;
343 
344 	unsigned short		max_segments;
345 	unsigned short		max_integrity_segments;
346 	unsigned short		max_discard_segments;
347 
348 	unsigned char		misaligned;
349 	unsigned char		discard_misaligned;
350 	unsigned char		raid_partial_stripes_expensive;
351 	enum blk_zoned_model	zoned;
352 };
353 
354 typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,
355 			       void *data);
356 
357 #ifdef CONFIG_BLK_DEV_ZONED
358 
359 #define BLK_ALL_ZONES  ((unsigned int)-1)
360 int blkdev_report_zones(struct block_device *bdev, sector_t sector,
361 			unsigned int nr_zones, report_zones_cb cb, void *data);
362 unsigned int blkdev_nr_zones(struct gendisk *disk);
363 extern int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
364 			    sector_t sectors, sector_t nr_sectors,
365 			    gfp_t gfp_mask);
366 int blk_revalidate_disk_zones(struct gendisk *disk,
367 			      void (*update_driver_data)(struct gendisk *disk));
368 
369 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
370 				     unsigned int cmd, unsigned long arg);
371 extern int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
372 				  unsigned int cmd, unsigned long arg);
373 
374 #else /* CONFIG_BLK_DEV_ZONED */
375 
376 static inline unsigned int blkdev_nr_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_zone_mgmt_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 
406 	const struct blk_mq_ops	*mq_ops;
407 
408 	/* sw queues */
409 	struct blk_mq_ctx __percpu	*queue_ctx;
410 
411 	unsigned int		queue_depth;
412 
413 	/* hw dispatch queues */
414 	struct blk_mq_hw_ctx	**queue_hw_ctx;
415 	unsigned int		nr_hw_queues;
416 
417 	struct backing_dev_info	*backing_dev_info;
418 
419 	/*
420 	 * The queue owner gets to use this for whatever they like.
421 	 * ll_rw_blk doesn't touch it.
422 	 */
423 	void			*queuedata;
424 
425 	/*
426 	 * various queue flags, see QUEUE_* below
427 	 */
428 	unsigned long		queue_flags;
429 	/*
430 	 * Number of contexts that have called blk_set_pm_only(). If this
431 	 * counter is above zero then only RQF_PM and RQF_PREEMPT requests are
432 	 * processed.
433 	 */
434 	atomic_t		pm_only;
435 
436 	/*
437 	 * ida allocated id for this queue.  Used to index queues from
438 	 * ioctx.
439 	 */
440 	int			id;
441 
442 	/*
443 	 * queue needs bounce pages for pages above this limit
444 	 */
445 	gfp_t			bounce_gfp;
446 
447 	spinlock_t		queue_lock;
448 
449 	/*
450 	 * queue kobject
451 	 */
452 	struct kobject kobj;
453 
454 	/*
455 	 * mq queue kobject
456 	 */
457 	struct kobject *mq_kobj;
458 
459 #ifdef  CONFIG_BLK_DEV_INTEGRITY
460 	struct blk_integrity integrity;
461 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
462 
463 #ifdef CONFIG_PM
464 	struct device		*dev;
465 	int			rpm_status;
466 	unsigned int		nr_pending;
467 #endif
468 
469 	/*
470 	 * queue settings
471 	 */
472 	unsigned long		nr_requests;	/* Max # of requests */
473 
474 	unsigned int		dma_pad_mask;
475 	unsigned int		dma_alignment;
476 
477 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
478 	/* Inline crypto capabilities */
479 	struct blk_keyslot_manager *ksm;
480 #endif
481 
482 	unsigned int		rq_timeout;
483 	int			poll_nsec;
484 
485 	struct blk_stat_callback	*poll_cb;
486 	struct blk_rq_stat	poll_stat[BLK_MQ_POLL_STATS_BKTS];
487 
488 	struct timer_list	timeout;
489 	struct work_struct	timeout_work;
490 
491 	struct list_head	icq_list;
492 #ifdef CONFIG_BLK_CGROUP
493 	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
494 	struct blkcg_gq		*root_blkg;
495 	struct list_head	blkg_list;
496 #endif
497 
498 	struct queue_limits	limits;
499 
500 	unsigned int		required_elevator_features;
501 
502 #ifdef CONFIG_BLK_DEV_ZONED
503 	/*
504 	 * Zoned block device information for request dispatch control.
505 	 * nr_zones is the total number of zones of the device. This is always
506 	 * 0 for regular block devices. conv_zones_bitmap is a bitmap of nr_zones
507 	 * bits which indicates if a zone is conventional (bit set) or
508 	 * sequential (bit clear). seq_zones_wlock is a bitmap of nr_zones
509 	 * bits which indicates if a zone is write locked, that is, if a write
510 	 * request targeting the zone was dispatched. All three fields are
511 	 * initialized by the low level device driver (e.g. scsi/sd.c).
512 	 * Stacking drivers (device mappers) may or may not initialize
513 	 * these fields.
514 	 *
515 	 * Reads of this information must be protected with blk_queue_enter() /
516 	 * blk_queue_exit(). Modifying this information is only allowed while
517 	 * no requests are being processed. See also blk_mq_freeze_queue() and
518 	 * blk_mq_unfreeze_queue().
519 	 */
520 	unsigned int		nr_zones;
521 	unsigned long		*conv_zones_bitmap;
522 	unsigned long		*seq_zones_wlock;
523 #endif /* CONFIG_BLK_DEV_ZONED */
524 
525 	/*
526 	 * sg stuff
527 	 */
528 	unsigned int		sg_timeout;
529 	unsigned int		sg_reserved_size;
530 	int			node;
531 #ifdef CONFIG_BLK_DEV_IO_TRACE
532 	struct blk_trace __rcu	*blk_trace;
533 	struct mutex		blk_trace_mutex;
534 #endif
535 	/*
536 	 * for flush operations
537 	 */
538 	struct blk_flush_queue	*fq;
539 
540 	struct list_head	requeue_list;
541 	spinlock_t		requeue_lock;
542 	struct delayed_work	requeue_work;
543 
544 	struct mutex		sysfs_lock;
545 	struct mutex		sysfs_dir_lock;
546 
547 	/*
548 	 * for reusing dead hctx instance in case of updating
549 	 * nr_hw_queues
550 	 */
551 	struct list_head	unused_hctx_list;
552 	spinlock_t		unused_hctx_lock;
553 
554 	int			mq_freeze_depth;
555 
556 #if defined(CONFIG_BLK_DEV_BSG)
557 	struct bsg_class_device bsg_dev;
558 #endif
559 
560 #ifdef CONFIG_BLK_DEV_THROTTLING
561 	/* Throttle data */
562 	struct throtl_data *td;
563 #endif
564 	struct rcu_head		rcu_head;
565 	wait_queue_head_t	mq_freeze_wq;
566 	/*
567 	 * Protect concurrent access to q_usage_counter by
568 	 * percpu_ref_kill() and percpu_ref_reinit().
569 	 */
570 	struct mutex		mq_freeze_lock;
571 	struct percpu_ref	q_usage_counter;
572 
573 	struct blk_mq_tag_set	*tag_set;
574 	struct list_head	tag_set_list;
575 	struct bio_set		bio_split;
576 
577 #ifdef CONFIG_BLK_DEBUG_FS
578 	struct dentry		*debugfs_dir;
579 	struct dentry		*sched_debugfs_dir;
580 	struct dentry		*rqos_debugfs_dir;
581 #endif
582 
583 	bool			mq_sysfs_init_done;
584 
585 	size_t			cmd_size;
586 
587 	struct work_struct	release_work;
588 
589 #define BLK_MAX_WRITE_HINTS	5
590 	u64			write_hints[BLK_MAX_WRITE_HINTS];
591 };
592 
593 /* Keep blk_queue_flag_name[] in sync with the definitions below */
594 #define QUEUE_FLAG_STOPPED	0	/* queue is stopped */
595 #define QUEUE_FLAG_DYING	1	/* queue being torn down */
596 #define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
597 #define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
598 #define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
599 #define QUEUE_FLAG_NONROT	6	/* non-rotational device (SSD) */
600 #define QUEUE_FLAG_VIRT		QUEUE_FLAG_NONROT /* paravirt device */
601 #define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
602 #define QUEUE_FLAG_DISCARD	8	/* supports DISCARD */
603 #define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
604 #define QUEUE_FLAG_ADD_RANDOM	10	/* Contributes to random pool */
605 #define QUEUE_FLAG_SECERASE	11	/* supports secure erase */
606 #define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
607 #define QUEUE_FLAG_DEAD		13	/* queue tear-down finished */
608 #define QUEUE_FLAG_INIT_DONE	14	/* queue is initialized */
609 #define QUEUE_FLAG_POLL		16	/* IO polling enabled if set */
610 #define QUEUE_FLAG_WC		17	/* Write back caching */
611 #define QUEUE_FLAG_FUA		18	/* device supports FUA writes */
612 #define QUEUE_FLAG_DAX		19	/* device supports DAX */
613 #define QUEUE_FLAG_STATS	20	/* track IO start and completion times */
614 #define QUEUE_FLAG_POLL_STATS	21	/* collecting stats for hybrid polling */
615 #define QUEUE_FLAG_REGISTERED	22	/* queue has been registered to a disk */
616 #define QUEUE_FLAG_SCSI_PASSTHROUGH 23	/* queue supports SCSI commands */
617 #define QUEUE_FLAG_QUIESCED	24	/* queue has been quiesced */
618 #define QUEUE_FLAG_PCI_P2PDMA	25	/* device supports PCI p2p requests */
619 #define QUEUE_FLAG_ZONE_RESETALL 26	/* supports Zone Reset All */
620 #define QUEUE_FLAG_RQ_ALLOC_TIME 27	/* record rq->alloc_time_ns */
621 
622 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
623 				 (1 << QUEUE_FLAG_SAME_COMP))
624 
625 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
626 void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
627 bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
628 
629 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
630 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
631 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
632 #define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
633 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
634 #define blk_queue_noxmerges(q)	\
635 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
636 #define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
637 #define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
638 #define blk_queue_add_random(q)	test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
639 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
640 #define blk_queue_zone_resetall(q)	\
641 	test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
642 #define blk_queue_secure_erase(q) \
643 	(test_bit(QUEUE_FLAG_SECERASE, &(q)->queue_flags))
644 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
645 #define blk_queue_scsi_passthrough(q)	\
646 	test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
647 #define blk_queue_pci_p2pdma(q)	\
648 	test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
649 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
650 #define blk_queue_rq_alloc_time(q)	\
651 	test_bit(QUEUE_FLAG_RQ_ALLOC_TIME, &(q)->queue_flags)
652 #else
653 #define blk_queue_rq_alloc_time(q)	false
654 #endif
655 
656 #define blk_noretry_request(rq) \
657 	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
658 			     REQ_FAILFAST_DRIVER))
659 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
660 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
661 #define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
662 #define blk_queue_registered(q)	test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
663 
664 extern void blk_set_pm_only(struct request_queue *q);
665 extern void blk_clear_pm_only(struct request_queue *q);
666 
667 static inline bool blk_account_rq(struct request *rq)
668 {
669 	return (rq->rq_flags & RQF_STARTED) && !blk_rq_is_passthrough(rq);
670 }
671 
672 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
673 
674 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
675 
676 #define rq_dma_dir(rq) \
677 	(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
678 
679 #define dma_map_bvec(dev, bv, dir, attrs) \
680 	dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
681 	(dir), (attrs))
682 
683 static inline bool queue_is_mq(struct request_queue *q)
684 {
685 	return q->mq_ops;
686 }
687 
688 static inline enum blk_zoned_model
689 blk_queue_zoned_model(struct request_queue *q)
690 {
691 	return q->limits.zoned;
692 }
693 
694 static inline bool blk_queue_is_zoned(struct request_queue *q)
695 {
696 	switch (blk_queue_zoned_model(q)) {
697 	case BLK_ZONED_HA:
698 	case BLK_ZONED_HM:
699 		return true;
700 	default:
701 		return false;
702 	}
703 }
704 
705 static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
706 {
707 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
708 }
709 
710 #ifdef CONFIG_BLK_DEV_ZONED
711 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
712 {
713 	return blk_queue_is_zoned(q) ? q->nr_zones : 0;
714 }
715 
716 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
717 					     sector_t sector)
718 {
719 	if (!blk_queue_is_zoned(q))
720 		return 0;
721 	return sector >> ilog2(q->limits.chunk_sectors);
722 }
723 
724 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
725 					 sector_t sector)
726 {
727 	if (!blk_queue_is_zoned(q))
728 		return false;
729 	if (!q->conv_zones_bitmap)
730 		return true;
731 	return !test_bit(blk_queue_zone_no(q, sector), q->conv_zones_bitmap);
732 }
733 #else /* CONFIG_BLK_DEV_ZONED */
734 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
735 {
736 	return 0;
737 }
738 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
739 					 sector_t sector)
740 {
741 	return false;
742 }
743 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
744 					     sector_t sector)
745 {
746 	return 0;
747 }
748 #endif /* CONFIG_BLK_DEV_ZONED */
749 
750 static inline bool rq_is_sync(struct request *rq)
751 {
752 	return op_is_sync(rq->cmd_flags);
753 }
754 
755 static inline bool rq_mergeable(struct request *rq)
756 {
757 	if (blk_rq_is_passthrough(rq))
758 		return false;
759 
760 	if (req_op(rq) == REQ_OP_FLUSH)
761 		return false;
762 
763 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
764 		return false;
765 
766 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
767 		return false;
768 
769 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
770 		return false;
771 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
772 		return false;
773 
774 	return true;
775 }
776 
777 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
778 {
779 	if (bio_page(a) == bio_page(b) &&
780 	    bio_offset(a) == bio_offset(b))
781 		return true;
782 
783 	return false;
784 }
785 
786 static inline unsigned int blk_queue_depth(struct request_queue *q)
787 {
788 	if (q->queue_depth)
789 		return q->queue_depth;
790 
791 	return q->nr_requests;
792 }
793 
794 extern unsigned long blk_max_low_pfn, blk_max_pfn;
795 
796 /*
797  * standard bounce addresses:
798  *
799  * BLK_BOUNCE_HIGH	: bounce all highmem pages
800  * BLK_BOUNCE_ANY	: don't bounce anything
801  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
802  */
803 
804 #if BITS_PER_LONG == 32
805 #define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
806 #else
807 #define BLK_BOUNCE_HIGH		-1ULL
808 #endif
809 #define BLK_BOUNCE_ANY		(-1ULL)
810 #define BLK_BOUNCE_ISA		(DMA_BIT_MASK(24))
811 
812 /*
813  * default timeout for SG_IO if none specified
814  */
815 #define BLK_DEFAULT_SG_TIMEOUT	(60 * HZ)
816 #define BLK_MIN_SG_TIMEOUT	(7 * HZ)
817 
818 struct rq_map_data {
819 	struct page **pages;
820 	int page_order;
821 	int nr_entries;
822 	unsigned long offset;
823 	int null_mapped;
824 	int from_user;
825 };
826 
827 struct req_iterator {
828 	struct bvec_iter iter;
829 	struct bio *bio;
830 };
831 
832 /* This should not be used directly - use rq_for_each_segment */
833 #define for_each_bio(_bio)		\
834 	for (; _bio; _bio = _bio->bi_next)
835 #define __rq_for_each_bio(_bio, rq)	\
836 	if ((rq->bio))			\
837 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
838 
839 #define rq_for_each_segment(bvl, _rq, _iter)			\
840 	__rq_for_each_bio(_iter.bio, _rq)			\
841 		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
842 
843 #define rq_for_each_bvec(bvl, _rq, _iter)			\
844 	__rq_for_each_bio(_iter.bio, _rq)			\
845 		bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
846 
847 #define rq_iter_last(bvec, _iter)				\
848 		(_iter.bio->bi_next == NULL &&			\
849 		 bio_iter_last(bvec, _iter.iter))
850 
851 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
852 # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
853 #endif
854 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
855 extern void rq_flush_dcache_pages(struct request *rq);
856 #else
857 static inline void rq_flush_dcache_pages(struct request *rq)
858 {
859 }
860 #endif
861 
862 extern int blk_register_queue(struct gendisk *disk);
863 extern void blk_unregister_queue(struct gendisk *disk);
864 extern blk_qc_t generic_make_request(struct bio *bio);
865 extern blk_qc_t direct_make_request(struct bio *bio);
866 extern void blk_rq_init(struct request_queue *q, struct request *rq);
867 extern void blk_put_request(struct request *);
868 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
869 				       blk_mq_req_flags_t flags);
870 extern int blk_lld_busy(struct request_queue *q);
871 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
872 			     struct bio_set *bs, gfp_t gfp_mask,
873 			     int (*bio_ctr)(struct bio *, struct bio *, void *),
874 			     void *data);
875 extern void blk_rq_unprep_clone(struct request *rq);
876 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
877 				     struct request *rq);
878 extern int blk_rq_append_bio(struct request *rq, struct bio **bio);
879 extern void blk_queue_split(struct request_queue *, struct bio **);
880 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
881 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
882 			      unsigned int, void __user *);
883 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
884 			  unsigned int, void __user *);
885 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
886 			 struct scsi_ioctl_command __user *);
887 extern int get_sg_io_hdr(struct sg_io_hdr *hdr, const void __user *argp);
888 extern int put_sg_io_hdr(const struct sg_io_hdr *hdr, void __user *argp);
889 
890 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
891 extern void blk_queue_exit(struct request_queue *q);
892 extern void blk_sync_queue(struct request_queue *q);
893 extern int blk_rq_map_user(struct request_queue *, struct request *,
894 			   struct rq_map_data *, void __user *, unsigned long,
895 			   gfp_t);
896 extern int blk_rq_unmap_user(struct bio *);
897 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
898 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
899 			       struct rq_map_data *, const struct iov_iter *,
900 			       gfp_t);
901 extern void blk_execute_rq(struct request_queue *, struct gendisk *,
902 			  struct request *, int);
903 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
904 				  struct request *, int, rq_end_io_fn *);
905 
906 /* Helper to convert REQ_OP_XXX to its string format XXX */
907 extern const char *blk_op_str(unsigned int op);
908 
909 int blk_status_to_errno(blk_status_t status);
910 blk_status_t errno_to_blk_status(int errno);
911 
912 int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin);
913 
914 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
915 {
916 	return bdev->bd_disk->queue;	/* this is never NULL */
917 }
918 
919 /*
920  * The basic unit of block I/O is a sector. It is used in a number of contexts
921  * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
922  * bytes. Variables of type sector_t represent an offset or size that is a
923  * multiple of 512 bytes. Hence these two constants.
924  */
925 #ifndef SECTOR_SHIFT
926 #define SECTOR_SHIFT 9
927 #endif
928 #ifndef SECTOR_SIZE
929 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
930 #endif
931 
932 /*
933  * blk_rq_pos()			: the current sector
934  * blk_rq_bytes()		: bytes left in the entire request
935  * blk_rq_cur_bytes()		: bytes left in the current segment
936  * blk_rq_err_bytes()		: bytes left till the next error boundary
937  * blk_rq_sectors()		: sectors left in the entire request
938  * blk_rq_cur_sectors()		: sectors left in the current segment
939  * blk_rq_stats_sectors()	: sectors of the entire request used for stats
940  */
941 static inline sector_t blk_rq_pos(const struct request *rq)
942 {
943 	return rq->__sector;
944 }
945 
946 static inline unsigned int blk_rq_bytes(const struct request *rq)
947 {
948 	return rq->__data_len;
949 }
950 
951 static inline int blk_rq_cur_bytes(const struct request *rq)
952 {
953 	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
954 }
955 
956 extern unsigned int blk_rq_err_bytes(const struct request *rq);
957 
958 static inline unsigned int blk_rq_sectors(const struct request *rq)
959 {
960 	return blk_rq_bytes(rq) >> SECTOR_SHIFT;
961 }
962 
963 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
964 {
965 	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
966 }
967 
968 static inline unsigned int blk_rq_stats_sectors(const struct request *rq)
969 {
970 	return rq->stats_sectors;
971 }
972 
973 #ifdef CONFIG_BLK_DEV_ZONED
974 
975 /* Helper to convert BLK_ZONE_ZONE_XXX to its string format XXX */
976 const char *blk_zone_cond_str(enum blk_zone_cond zone_cond);
977 
978 static inline unsigned int blk_rq_zone_no(struct request *rq)
979 {
980 	return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
981 }
982 
983 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
984 {
985 	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
986 }
987 #endif /* CONFIG_BLK_DEV_ZONED */
988 
989 /*
990  * Some commands like WRITE SAME have a payload or data transfer size which
991  * is different from the size of the request.  Any driver that supports such
992  * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
993  * calculate the data transfer size.
994  */
995 static inline unsigned int blk_rq_payload_bytes(struct request *rq)
996 {
997 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
998 		return rq->special_vec.bv_len;
999 	return blk_rq_bytes(rq);
1000 }
1001 
1002 /*
1003  * Return the first full biovec in the request.  The caller needs to check that
1004  * there are any bvecs before calling this helper.
1005  */
1006 static inline struct bio_vec req_bvec(struct request *rq)
1007 {
1008 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1009 		return rq->special_vec;
1010 	return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
1011 }
1012 
1013 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
1014 						     int op)
1015 {
1016 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
1017 		return min(q->limits.max_discard_sectors,
1018 			   UINT_MAX >> SECTOR_SHIFT);
1019 
1020 	if (unlikely(op == REQ_OP_WRITE_SAME))
1021 		return q->limits.max_write_same_sectors;
1022 
1023 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
1024 		return q->limits.max_write_zeroes_sectors;
1025 
1026 	return q->limits.max_sectors;
1027 }
1028 
1029 /*
1030  * Return maximum size of a request at given offset. Only valid for
1031  * file system requests.
1032  */
1033 static inline unsigned int blk_max_size_offset(struct request_queue *q,
1034 					       sector_t offset)
1035 {
1036 	if (!q->limits.chunk_sectors)
1037 		return q->limits.max_sectors;
1038 
1039 	return min(q->limits.max_sectors, (unsigned int)(q->limits.chunk_sectors -
1040 			(offset & (q->limits.chunk_sectors - 1))));
1041 }
1042 
1043 static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
1044 						  sector_t offset)
1045 {
1046 	struct request_queue *q = rq->q;
1047 
1048 	if (blk_rq_is_passthrough(rq))
1049 		return q->limits.max_hw_sectors;
1050 
1051 	if (!q->limits.chunk_sectors ||
1052 	    req_op(rq) == REQ_OP_DISCARD ||
1053 	    req_op(rq) == REQ_OP_SECURE_ERASE)
1054 		return blk_queue_get_max_sectors(q, req_op(rq));
1055 
1056 	return min(blk_max_size_offset(q, offset),
1057 			blk_queue_get_max_sectors(q, req_op(rq)));
1058 }
1059 
1060 static inline unsigned int blk_rq_count_bios(struct request *rq)
1061 {
1062 	unsigned int nr_bios = 0;
1063 	struct bio *bio;
1064 
1065 	__rq_for_each_bio(bio, rq)
1066 		nr_bios++;
1067 
1068 	return nr_bios;
1069 }
1070 
1071 void blk_steal_bios(struct bio_list *list, struct request *rq);
1072 
1073 /*
1074  * Request completion related functions.
1075  *
1076  * blk_update_request() completes given number of bytes and updates
1077  * the request without completing it.
1078  */
1079 extern bool blk_update_request(struct request *rq, blk_status_t error,
1080 			       unsigned int nr_bytes);
1081 
1082 extern void __blk_complete_request(struct request *);
1083 extern void blk_abort_request(struct request *);
1084 
1085 /*
1086  * Access functions for manipulating queue properties
1087  */
1088 extern void blk_cleanup_queue(struct request_queue *);
1089 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1090 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1091 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1092 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1093 extern void blk_queue_max_discard_segments(struct request_queue *,
1094 		unsigned short);
1095 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1096 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1097 		unsigned int max_discard_sectors);
1098 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1099 		unsigned int max_write_same_sectors);
1100 extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
1101 		unsigned int max_write_same_sectors);
1102 extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
1103 extern void blk_queue_max_zone_append_sectors(struct request_queue *q,
1104 		unsigned int max_zone_append_sectors);
1105 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1106 extern void blk_queue_alignment_offset(struct request_queue *q,
1107 				       unsigned int alignment);
1108 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1109 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1110 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1111 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1112 extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth);
1113 extern void blk_set_default_limits(struct queue_limits *lim);
1114 extern void blk_set_stacking_limits(struct queue_limits *lim);
1115 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1116 			    sector_t offset);
1117 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1118 			    sector_t offset);
1119 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1120 			      sector_t offset);
1121 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1122 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1123 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1124 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1125 extern void blk_queue_dma_alignment(struct request_queue *, int);
1126 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1127 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1128 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
1129 extern void blk_queue_required_elevator_features(struct request_queue *q,
1130 						 unsigned int features);
1131 extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
1132 					      struct device *dev);
1133 
1134 /*
1135  * Number of physical segments as sent to the device.
1136  *
1137  * Normally this is the number of discontiguous data segments sent by the
1138  * submitter.  But for data-less command like discard we might have no
1139  * actual data segments submitted, but the driver might have to add it's
1140  * own special payload.  In that case we still return 1 here so that this
1141  * special payload will be mapped.
1142  */
1143 static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
1144 {
1145 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
1146 		return 1;
1147 	return rq->nr_phys_segments;
1148 }
1149 
1150 /*
1151  * Number of discard segments (or ranges) the driver needs to fill in.
1152  * Each discard bio merged into a request is counted as one segment.
1153  */
1154 static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
1155 {
1156 	return max_t(unsigned short, rq->nr_phys_segments, 1);
1157 }
1158 
1159 int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
1160 		struct scatterlist *sglist, struct scatterlist **last_sg);
1161 static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq,
1162 		struct scatterlist *sglist)
1163 {
1164 	struct scatterlist *last_sg = NULL;
1165 
1166 	return __blk_rq_map_sg(q, rq, sglist, &last_sg);
1167 }
1168 extern void blk_dump_rq_flags(struct request *, char *);
1169 extern long nr_blockdev_pages(void);
1170 
1171 bool __must_check blk_get_queue(struct request_queue *);
1172 struct request_queue *blk_alloc_queue(make_request_fn make_request, int node_id);
1173 extern void blk_put_queue(struct request_queue *);
1174 extern void blk_set_queue_dying(struct request_queue *);
1175 
1176 /*
1177  * blk_plug permits building a queue of related requests by holding the I/O
1178  * fragments for a short period. This allows merging of sequential requests
1179  * into single larger request. As the requests are moved from a per-task list to
1180  * the device's request_queue in a batch, this results in improved scalability
1181  * as the lock contention for request_queue lock is reduced.
1182  *
1183  * It is ok not to disable preemption when adding the request to the plug list
1184  * or when attempting a merge, because blk_schedule_flush_list() will only flush
1185  * the plug list when the task sleeps by itself. For details, please see
1186  * schedule() where blk_schedule_flush_plug() is called.
1187  */
1188 struct blk_plug {
1189 	struct list_head mq_list; /* blk-mq requests */
1190 	struct list_head cb_list; /* md requires an unplug callback */
1191 	unsigned short rq_count;
1192 	bool multiple_queues;
1193 };
1194 #define BLK_MAX_REQUEST_COUNT 16
1195 #define BLK_PLUG_FLUSH_SIZE (128 * 1024)
1196 
1197 struct blk_plug_cb;
1198 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1199 struct blk_plug_cb {
1200 	struct list_head list;
1201 	blk_plug_cb_fn callback;
1202 	void *data;
1203 };
1204 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1205 					     void *data, int size);
1206 extern void blk_start_plug(struct blk_plug *);
1207 extern void blk_finish_plug(struct blk_plug *);
1208 extern void blk_flush_plug_list(struct blk_plug *, bool);
1209 
1210 static inline void blk_flush_plug(struct task_struct *tsk)
1211 {
1212 	struct blk_plug *plug = tsk->plug;
1213 
1214 	if (plug)
1215 		blk_flush_plug_list(plug, false);
1216 }
1217 
1218 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1219 {
1220 	struct blk_plug *plug = tsk->plug;
1221 
1222 	if (plug)
1223 		blk_flush_plug_list(plug, true);
1224 }
1225 
1226 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1227 {
1228 	struct blk_plug *plug = tsk->plug;
1229 
1230 	return plug &&
1231 		 (!list_empty(&plug->mq_list) ||
1232 		 !list_empty(&plug->cb_list));
1233 }
1234 
1235 extern void blk_io_schedule(void);
1236 
1237 int blkdev_issue_flush(struct block_device *, gfp_t);
1238 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1239 		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1240 
1241 #define BLKDEV_DISCARD_SECURE	(1 << 0)	/* issue a secure erase */
1242 
1243 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1244 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1245 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1246 		sector_t nr_sects, gfp_t gfp_mask, int flags,
1247 		struct bio **biop);
1248 
1249 #define BLKDEV_ZERO_NOUNMAP	(1 << 0)  /* do not free blocks */
1250 #define BLKDEV_ZERO_NOFALLBACK	(1 << 1)  /* don't write explicit zeroes */
1251 
1252 extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1253 		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
1254 		unsigned flags);
1255 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1256 		sector_t nr_sects, gfp_t gfp_mask, unsigned flags);
1257 
1258 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1259 		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1260 {
1261 	return blkdev_issue_discard(sb->s_bdev,
1262 				    block << (sb->s_blocksize_bits -
1263 					      SECTOR_SHIFT),
1264 				    nr_blocks << (sb->s_blocksize_bits -
1265 						  SECTOR_SHIFT),
1266 				    gfp_mask, flags);
1267 }
1268 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1269 		sector_t nr_blocks, gfp_t gfp_mask)
1270 {
1271 	return blkdev_issue_zeroout(sb->s_bdev,
1272 				    block << (sb->s_blocksize_bits -
1273 					      SECTOR_SHIFT),
1274 				    nr_blocks << (sb->s_blocksize_bits -
1275 						  SECTOR_SHIFT),
1276 				    gfp_mask, 0);
1277 }
1278 
1279 extern int blk_verify_command(unsigned char *cmd, fmode_t mode);
1280 
1281 enum blk_default_limits {
1282 	BLK_MAX_SEGMENTS	= 128,
1283 	BLK_SAFE_MAX_SECTORS	= 255,
1284 	BLK_DEF_MAX_SECTORS	= 2560,
1285 	BLK_MAX_SEGMENT_SIZE	= 65536,
1286 	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,
1287 };
1288 
1289 static inline unsigned long queue_segment_boundary(const struct request_queue *q)
1290 {
1291 	return q->limits.seg_boundary_mask;
1292 }
1293 
1294 static inline unsigned long queue_virt_boundary(const struct request_queue *q)
1295 {
1296 	return q->limits.virt_boundary_mask;
1297 }
1298 
1299 static inline unsigned int queue_max_sectors(const struct request_queue *q)
1300 {
1301 	return q->limits.max_sectors;
1302 }
1303 
1304 static inline unsigned int queue_max_hw_sectors(const struct request_queue *q)
1305 {
1306 	return q->limits.max_hw_sectors;
1307 }
1308 
1309 static inline unsigned short queue_max_segments(const struct request_queue *q)
1310 {
1311 	return q->limits.max_segments;
1312 }
1313 
1314 static inline unsigned short queue_max_discard_segments(const struct request_queue *q)
1315 {
1316 	return q->limits.max_discard_segments;
1317 }
1318 
1319 static inline unsigned int queue_max_segment_size(const struct request_queue *q)
1320 {
1321 	return q->limits.max_segment_size;
1322 }
1323 
1324 static inline unsigned int queue_max_zone_append_sectors(const struct request_queue *q)
1325 {
1326 	return q->limits.max_zone_append_sectors;
1327 }
1328 
1329 static inline unsigned queue_logical_block_size(const struct request_queue *q)
1330 {
1331 	int retval = 512;
1332 
1333 	if (q && q->limits.logical_block_size)
1334 		retval = q->limits.logical_block_size;
1335 
1336 	return retval;
1337 }
1338 
1339 static inline unsigned int bdev_logical_block_size(struct block_device *bdev)
1340 {
1341 	return queue_logical_block_size(bdev_get_queue(bdev));
1342 }
1343 
1344 static inline unsigned int queue_physical_block_size(const struct request_queue *q)
1345 {
1346 	return q->limits.physical_block_size;
1347 }
1348 
1349 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1350 {
1351 	return queue_physical_block_size(bdev_get_queue(bdev));
1352 }
1353 
1354 static inline unsigned int queue_io_min(const struct request_queue *q)
1355 {
1356 	return q->limits.io_min;
1357 }
1358 
1359 static inline int bdev_io_min(struct block_device *bdev)
1360 {
1361 	return queue_io_min(bdev_get_queue(bdev));
1362 }
1363 
1364 static inline unsigned int queue_io_opt(const struct request_queue *q)
1365 {
1366 	return q->limits.io_opt;
1367 }
1368 
1369 static inline int bdev_io_opt(struct block_device *bdev)
1370 {
1371 	return queue_io_opt(bdev_get_queue(bdev));
1372 }
1373 
1374 static inline int queue_alignment_offset(const struct request_queue *q)
1375 {
1376 	if (q->limits.misaligned)
1377 		return -1;
1378 
1379 	return q->limits.alignment_offset;
1380 }
1381 
1382 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1383 {
1384 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1385 	unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
1386 		<< SECTOR_SHIFT;
1387 
1388 	return (granularity + lim->alignment_offset - alignment) % granularity;
1389 }
1390 
1391 static inline int bdev_alignment_offset(struct block_device *bdev)
1392 {
1393 	struct request_queue *q = bdev_get_queue(bdev);
1394 
1395 	if (q->limits.misaligned)
1396 		return -1;
1397 
1398 	if (bdev != bdev->bd_contains)
1399 		return bdev->bd_part->alignment_offset;
1400 
1401 	return q->limits.alignment_offset;
1402 }
1403 
1404 static inline int queue_discard_alignment(const struct request_queue *q)
1405 {
1406 	if (q->limits.discard_misaligned)
1407 		return -1;
1408 
1409 	return q->limits.discard_alignment;
1410 }
1411 
1412 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1413 {
1414 	unsigned int alignment, granularity, offset;
1415 
1416 	if (!lim->max_discard_sectors)
1417 		return 0;
1418 
1419 	/* Why are these in bytes, not sectors? */
1420 	alignment = lim->discard_alignment >> SECTOR_SHIFT;
1421 	granularity = lim->discard_granularity >> SECTOR_SHIFT;
1422 	if (!granularity)
1423 		return 0;
1424 
1425 	/* Offset of the partition start in 'granularity' sectors */
1426 	offset = sector_div(sector, granularity);
1427 
1428 	/* And why do we do this modulus *again* in blkdev_issue_discard()? */
1429 	offset = (granularity + alignment - offset) % granularity;
1430 
1431 	/* Turn it back into bytes, gaah */
1432 	return offset << SECTOR_SHIFT;
1433 }
1434 
1435 static inline int bdev_discard_alignment(struct block_device *bdev)
1436 {
1437 	struct request_queue *q = bdev_get_queue(bdev);
1438 
1439 	if (bdev != bdev->bd_contains)
1440 		return bdev->bd_part->discard_alignment;
1441 
1442 	return q->limits.discard_alignment;
1443 }
1444 
1445 static inline unsigned int bdev_write_same(struct block_device *bdev)
1446 {
1447 	struct request_queue *q = bdev_get_queue(bdev);
1448 
1449 	if (q)
1450 		return q->limits.max_write_same_sectors;
1451 
1452 	return 0;
1453 }
1454 
1455 static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev)
1456 {
1457 	struct request_queue *q = bdev_get_queue(bdev);
1458 
1459 	if (q)
1460 		return q->limits.max_write_zeroes_sectors;
1461 
1462 	return 0;
1463 }
1464 
1465 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
1466 {
1467 	struct request_queue *q = bdev_get_queue(bdev);
1468 
1469 	if (q)
1470 		return blk_queue_zoned_model(q);
1471 
1472 	return BLK_ZONED_NONE;
1473 }
1474 
1475 static inline bool bdev_is_zoned(struct block_device *bdev)
1476 {
1477 	struct request_queue *q = bdev_get_queue(bdev);
1478 
1479 	if (q)
1480 		return blk_queue_is_zoned(q);
1481 
1482 	return false;
1483 }
1484 
1485 static inline sector_t bdev_zone_sectors(struct block_device *bdev)
1486 {
1487 	struct request_queue *q = bdev_get_queue(bdev);
1488 
1489 	if (q)
1490 		return blk_queue_zone_sectors(q);
1491 	return 0;
1492 }
1493 
1494 static inline int queue_dma_alignment(const struct request_queue *q)
1495 {
1496 	return q ? q->dma_alignment : 511;
1497 }
1498 
1499 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1500 				 unsigned int len)
1501 {
1502 	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1503 	return !(addr & alignment) && !(len & alignment);
1504 }
1505 
1506 /* assumes size > 256 */
1507 static inline unsigned int blksize_bits(unsigned int size)
1508 {
1509 	unsigned int bits = 8;
1510 	do {
1511 		bits++;
1512 		size >>= 1;
1513 	} while (size > 256);
1514 	return bits;
1515 }
1516 
1517 static inline unsigned int block_size(struct block_device *bdev)
1518 {
1519 	return bdev->bd_block_size;
1520 }
1521 
1522 int kblockd_schedule_work(struct work_struct *work);
1523 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1524 
1525 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1526 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1527 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1528 	MODULE_ALIAS("block-major-" __stringify(major) "-*")
1529 
1530 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1531 
1532 enum blk_integrity_flags {
1533 	BLK_INTEGRITY_VERIFY		= 1 << 0,
1534 	BLK_INTEGRITY_GENERATE		= 1 << 1,
1535 	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
1536 	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
1537 };
1538 
1539 struct blk_integrity_iter {
1540 	void			*prot_buf;
1541 	void			*data_buf;
1542 	sector_t		seed;
1543 	unsigned int		data_size;
1544 	unsigned short		interval;
1545 	const char		*disk_name;
1546 };
1547 
1548 typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
1549 typedef void (integrity_prepare_fn) (struct request *);
1550 typedef void (integrity_complete_fn) (struct request *, unsigned int);
1551 
1552 struct blk_integrity_profile {
1553 	integrity_processing_fn		*generate_fn;
1554 	integrity_processing_fn		*verify_fn;
1555 	integrity_prepare_fn		*prepare_fn;
1556 	integrity_complete_fn		*complete_fn;
1557 	const char			*name;
1558 };
1559 
1560 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1561 extern void blk_integrity_unregister(struct gendisk *);
1562 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1563 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1564 				   struct scatterlist *);
1565 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1566 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1567 				   struct request *);
1568 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1569 				    struct bio *);
1570 
1571 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1572 {
1573 	struct blk_integrity *bi = &disk->queue->integrity;
1574 
1575 	if (!bi->profile)
1576 		return NULL;
1577 
1578 	return bi;
1579 }
1580 
1581 static inline
1582 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1583 {
1584 	return blk_get_integrity(bdev->bd_disk);
1585 }
1586 
1587 static inline bool
1588 blk_integrity_queue_supports_integrity(struct request_queue *q)
1589 {
1590 	return q->integrity.profile;
1591 }
1592 
1593 static inline bool blk_integrity_rq(struct request *rq)
1594 {
1595 	return rq->cmd_flags & REQ_INTEGRITY;
1596 }
1597 
1598 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1599 						    unsigned int segs)
1600 {
1601 	q->limits.max_integrity_segments = segs;
1602 }
1603 
1604 static inline unsigned short
1605 queue_max_integrity_segments(const struct request_queue *q)
1606 {
1607 	return q->limits.max_integrity_segments;
1608 }
1609 
1610 /**
1611  * bio_integrity_intervals - Return number of integrity intervals for a bio
1612  * @bi:		blk_integrity profile for device
1613  * @sectors:	Size of the bio in 512-byte sectors
1614  *
1615  * Description: The block layer calculates everything in 512 byte
1616  * sectors but integrity metadata is done in terms of the data integrity
1617  * interval size of the storage device.  Convert the block layer sectors
1618  * to the appropriate number of integrity intervals.
1619  */
1620 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1621 						   unsigned int sectors)
1622 {
1623 	return sectors >> (bi->interval_exp - 9);
1624 }
1625 
1626 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1627 					       unsigned int sectors)
1628 {
1629 	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
1630 }
1631 
1632 /*
1633  * Return the first bvec that contains integrity data.  Only drivers that are
1634  * limited to a single integrity segment should use this helper.
1635  */
1636 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1637 {
1638 	if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
1639 		return NULL;
1640 	return rq->bio->bi_integrity->bip_vec;
1641 }
1642 
1643 #else /* CONFIG_BLK_DEV_INTEGRITY */
1644 
1645 struct bio;
1646 struct block_device;
1647 struct gendisk;
1648 struct blk_integrity;
1649 
1650 static inline int blk_integrity_rq(struct request *rq)
1651 {
1652 	return 0;
1653 }
1654 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1655 					    struct bio *b)
1656 {
1657 	return 0;
1658 }
1659 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1660 					  struct bio *b,
1661 					  struct scatterlist *s)
1662 {
1663 	return 0;
1664 }
1665 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1666 {
1667 	return NULL;
1668 }
1669 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1670 {
1671 	return NULL;
1672 }
1673 static inline bool
1674 blk_integrity_queue_supports_integrity(struct request_queue *q)
1675 {
1676 	return false;
1677 }
1678 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1679 {
1680 	return 0;
1681 }
1682 static inline void blk_integrity_register(struct gendisk *d,
1683 					 struct blk_integrity *b)
1684 {
1685 }
1686 static inline void blk_integrity_unregister(struct gendisk *d)
1687 {
1688 }
1689 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1690 						    unsigned int segs)
1691 {
1692 }
1693 static inline unsigned short queue_max_integrity_segments(const struct request_queue *q)
1694 {
1695 	return 0;
1696 }
1697 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1698 					  struct request *r1,
1699 					  struct request *r2)
1700 {
1701 	return true;
1702 }
1703 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1704 					   struct request *r,
1705 					   struct bio *b)
1706 {
1707 	return true;
1708 }
1709 
1710 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
1711 						   unsigned int sectors)
1712 {
1713 	return 0;
1714 }
1715 
1716 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
1717 					       unsigned int sectors)
1718 {
1719 	return 0;
1720 }
1721 
1722 static inline struct bio_vec *rq_integrity_vec(struct request *rq)
1723 {
1724 	return NULL;
1725 }
1726 
1727 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1728 
1729 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1730 
1731 bool blk_ksm_register(struct blk_keyslot_manager *ksm, struct request_queue *q);
1732 
1733 void blk_ksm_unregister(struct request_queue *q);
1734 
1735 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1736 
1737 static inline bool blk_ksm_register(struct blk_keyslot_manager *ksm,
1738 				    struct request_queue *q)
1739 {
1740 	return true;
1741 }
1742 
1743 static inline void blk_ksm_unregister(struct request_queue *q) { }
1744 
1745 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
1746 
1747 
1748 struct block_device_operations {
1749 	int (*open) (struct block_device *, fmode_t);
1750 	void (*release) (struct gendisk *, fmode_t);
1751 	int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);
1752 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1753 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1754 	unsigned int (*check_events) (struct gendisk *disk,
1755 				      unsigned int clearing);
1756 	/* ->media_changed() is DEPRECATED, use ->check_events() instead */
1757 	int (*media_changed) (struct gendisk *);
1758 	void (*unlock_native_capacity) (struct gendisk *);
1759 	int (*revalidate_disk) (struct gendisk *);
1760 	int (*getgeo)(struct block_device *, struct hd_geometry *);
1761 	/* this callback is with swap_lock and sometimes page table lock held */
1762 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1763 	int (*report_zones)(struct gendisk *, sector_t sector,
1764 			unsigned int nr_zones, report_zones_cb cb, void *data);
1765 	char *(*devnode)(struct gendisk *disk, umode_t *mode);
1766 	struct module *owner;
1767 	const struct pr_ops *pr_ops;
1768 };
1769 
1770 #ifdef CONFIG_COMPAT
1771 extern int blkdev_compat_ptr_ioctl(struct block_device *, fmode_t,
1772 				      unsigned int, unsigned long);
1773 #else
1774 #define blkdev_compat_ptr_ioctl NULL
1775 #endif
1776 
1777 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1778 				 unsigned long);
1779 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1780 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1781 						struct writeback_control *);
1782 
1783 #ifdef CONFIG_BLK_DEV_ZONED
1784 bool blk_req_needs_zone_write_lock(struct request *rq);
1785 bool blk_req_zone_write_trylock(struct request *rq);
1786 void __blk_req_zone_write_lock(struct request *rq);
1787 void __blk_req_zone_write_unlock(struct request *rq);
1788 
1789 static inline void blk_req_zone_write_lock(struct request *rq)
1790 {
1791 	if (blk_req_needs_zone_write_lock(rq))
1792 		__blk_req_zone_write_lock(rq);
1793 }
1794 
1795 static inline void blk_req_zone_write_unlock(struct request *rq)
1796 {
1797 	if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
1798 		__blk_req_zone_write_unlock(rq);
1799 }
1800 
1801 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1802 {
1803 	return rq->q->seq_zones_wlock &&
1804 		test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
1805 }
1806 
1807 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1808 {
1809 	if (!blk_req_needs_zone_write_lock(rq))
1810 		return true;
1811 	return !blk_req_zone_is_write_locked(rq);
1812 }
1813 #else
1814 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
1815 {
1816 	return false;
1817 }
1818 
1819 static inline void blk_req_zone_write_lock(struct request *rq)
1820 {
1821 }
1822 
1823 static inline void blk_req_zone_write_unlock(struct request *rq)
1824 {
1825 }
1826 static inline bool blk_req_zone_is_write_locked(struct request *rq)
1827 {
1828 	return false;
1829 }
1830 
1831 static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
1832 {
1833 	return true;
1834 }
1835 #endif /* CONFIG_BLK_DEV_ZONED */
1836 
1837 #else /* CONFIG_BLOCK */
1838 
1839 struct block_device;
1840 
1841 /*
1842  * stubs for when the block layer is configured out
1843  */
1844 #define buffer_heads_over_limit 0
1845 
1846 static inline long nr_blockdev_pages(void)
1847 {
1848 	return 0;
1849 }
1850 
1851 struct blk_plug {
1852 };
1853 
1854 static inline void blk_start_plug(struct blk_plug *plug)
1855 {
1856 }
1857 
1858 static inline void blk_finish_plug(struct blk_plug *plug)
1859 {
1860 }
1861 
1862 static inline void blk_flush_plug(struct task_struct *task)
1863 {
1864 }
1865 
1866 static inline void blk_schedule_flush_plug(struct task_struct *task)
1867 {
1868 }
1869 
1870 
1871 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1872 {
1873 	return false;
1874 }
1875 
1876 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask)
1877 {
1878 	return 0;
1879 }
1880 
1881 #endif /* CONFIG_BLOCK */
1882 
1883 static inline void blk_wake_io_task(struct task_struct *waiter)
1884 {
1885 	/*
1886 	 * If we're polling, the task itself is doing the completions. For
1887 	 * that case, we don't need to signal a wakeup, it's enough to just
1888 	 * mark us as RUNNING.
1889 	 */
1890 	if (waiter == current)
1891 		__set_current_state(TASK_RUNNING);
1892 	else
1893 		wake_up_process(waiter);
1894 }
1895 
1896 #ifdef CONFIG_BLOCK
1897 unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
1898 		unsigned int op);
1899 void disk_end_io_acct(struct gendisk *disk, unsigned int op,
1900 		unsigned long start_time);
1901 
1902 /**
1903  * bio_start_io_acct - start I/O accounting for bio based drivers
1904  * @bio:	bio to start account for
1905  *
1906  * Returns the start time that should be passed back to bio_end_io_acct().
1907  */
1908 static inline unsigned long bio_start_io_acct(struct bio *bio)
1909 {
1910 	return disk_start_io_acct(bio->bi_disk, bio_sectors(bio), bio_op(bio));
1911 }
1912 
1913 /**
1914  * bio_end_io_acct - end I/O accounting for bio based drivers
1915  * @bio:	bio to end account for
1916  * @start:	start time returned by bio_start_io_acct()
1917  */
1918 static inline void bio_end_io_acct(struct bio *bio, unsigned long start_time)
1919 {
1920 	return disk_end_io_acct(bio->bi_disk, bio_op(bio), start_time);
1921 }
1922 #endif /* CONFIG_BLOCK */
1923 
1924 #endif
1925