1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
4 #include <linux/sched.h>
8 #include <linux/major.h>
9 #include <linux/genhd.h>
10 #include <linux/list.h>
11 #include <linux/llist.h>
12 #include <linux/timer.h>
13 #include <linux/workqueue.h>
14 #include <linux/pagemap.h>
15 #include <linux/backing-dev-defs.h>
16 #include <linux/wait.h>
17 #include <linux/mempool.h>
18 #include <linux/bio.h>
19 #include <linux/stringify.h>
20 #include <linux/gfp.h>
21 #include <linux/bsg.h>
22 #include <linux/smp.h>
23 #include <linux/rcupdate.h>
24 #include <linux/percpu-refcount.h>
25 #include <linux/scatterlist.h>
28 struct scsi_ioctl_command;
31 struct elevator_queue;
37 struct blk_flush_queue;
40 #define BLKDEV_MIN_RQ 4
41 #define BLKDEV_MAX_RQ 128 /* Default maximum */
44 * Maximum number of blkcg policies allowed to be registered concurrently.
45 * Defined here to simplify include dependency.
47 #define BLKCG_MAX_POLS 2
50 typedef void (rq_end_io_fn)(struct request *, int);
52 #define BLK_RL_SYNCFULL (1U << 0)
53 #define BLK_RL_ASYNCFULL (1U << 1)
56 struct request_queue *q; /* the queue this rl belongs to */
57 #ifdef CONFIG_BLK_CGROUP
58 struct blkcg_gq *blkg; /* blkg this request pool belongs to */
61 * count[], starved[], and wait[] are indexed by
62 * BLK_RW_SYNC/BLK_RW_ASYNC
67 wait_queue_head_t wait[2];
72 * request command types
74 enum rq_cmd_type_bits {
75 REQ_TYPE_FS = 1, /* fs request */
76 REQ_TYPE_BLOCK_PC, /* scsi command */
77 REQ_TYPE_DRV_PRIV, /* driver defined types from here */
80 #define BLK_MAX_CDB 16
83 * Try to put the fields that are referenced together in the same cacheline.
85 * If you modify this structure, make sure to update blk_rq_init() and
86 * especially blk_mq_rq_ctx_init() to take care of the added fields.
89 struct list_head queuelist;
91 struct call_single_data csd;
92 unsigned long fifo_time;
95 struct request_queue *q;
96 struct blk_mq_ctx *mq_ctx;
100 unsigned long atomic_flags;
104 /* the following two fields are internal, NEVER access directly */
105 unsigned int __data_len; /* total data len */
106 sector_t __sector; /* sector cursor */
112 * The hash is used inside the scheduler, and killed once the
113 * request reaches the dispatch list. The ipi_list is only used
114 * to queue the request for softirq completion, which is long
115 * after the request has been unhashed (and even removed from
116 * the dispatch list).
119 struct hlist_node hash; /* merge hash */
120 struct list_head ipi_list;
124 * The rb_node is only used inside the io scheduler, requests
125 * are pruned when moved to the dispatch queue. So let the
126 * completion_data share space with the rb_node.
129 struct rb_node rb_node; /* sort/lookup */
130 void *completion_data;
134 * Three pointers are available for the IO schedulers, if they need
135 * more they have to dynamically allocate it. Flush requests are
136 * never put on the IO scheduler. So let the flush fields share
137 * space with the elevator data.
147 struct list_head list;
148 rq_end_io_fn *saved_end_io;
152 struct gendisk *rq_disk;
153 struct hd_struct *part;
154 unsigned long start_time;
155 #ifdef CONFIG_BLK_CGROUP
156 struct request_list *rl; /* rl this rq is alloced from */
157 unsigned long long start_time_ns;
158 unsigned long long io_start_time_ns; /* when passed to hardware */
160 /* Number of scatter-gather DMA addr+len pairs after
161 * physical address coalescing is performed.
163 unsigned short nr_phys_segments;
164 #if defined(CONFIG_BLK_DEV_INTEGRITY)
165 unsigned short nr_integrity_segments;
168 unsigned short ioprio;
170 void *special; /* opaque pointer available for LLD use */
176 * when request is used as a packet command carrier
178 unsigned char __cmd[BLK_MAX_CDB];
180 unsigned short cmd_len;
182 unsigned int extra_len; /* length of alignment and padding */
183 unsigned int sense_len;
184 unsigned int resid_len; /* residual count */
187 unsigned long deadline;
188 struct list_head timeout_list;
189 unsigned int timeout;
193 * completion callback.
195 rq_end_io_fn *end_io;
199 struct request *next_rq;
201 ktime_t lat_hist_io_start;
202 int lat_hist_enabled;
205 static inline bool blk_rq_is_passthrough(struct request *rq)
207 return rq->cmd_type != REQ_TYPE_FS;
210 static inline unsigned short req_get_ioprio(struct request *req)
215 #include <linux/elevator.h>
217 struct blk_queue_ctx;
219 typedef void (request_fn_proc) (struct request_queue *q);
220 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
221 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
222 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
225 typedef void (softirq_done_fn)(struct request *);
226 typedef int (dma_drain_needed_fn)(struct request *);
227 typedef int (lld_busy_fn) (struct request_queue *q);
228 typedef int (bsg_job_fn) (struct bsg_job *);
230 enum blk_eh_timer_return {
236 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
238 enum blk_queue_state {
243 struct blk_queue_tag {
244 struct request **tag_index; /* map of busy tags */
245 unsigned long *tag_map; /* bit map of free/busy tags */
246 int busy; /* current depth */
247 int max_depth; /* what we will send to device */
248 int real_max_depth; /* what the array can hold */
249 atomic_t refcnt; /* map can be shared */
250 int alloc_policy; /* tag allocation policy */
251 int next_tag; /* next tag */
253 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
254 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
256 #define BLK_SCSI_MAX_CMDS (256)
257 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
259 struct queue_limits {
260 unsigned long bounce_pfn;
261 unsigned long seg_boundary_mask;
262 unsigned long virt_boundary_mask;
264 unsigned int max_hw_sectors;
265 unsigned int max_dev_sectors;
266 unsigned int chunk_sectors;
267 unsigned int max_sectors;
268 unsigned int max_segment_size;
269 unsigned int physical_block_size;
270 unsigned int alignment_offset;
273 unsigned int max_discard_sectors;
274 unsigned int max_hw_discard_sectors;
275 unsigned int max_write_same_sectors;
276 unsigned int discard_granularity;
277 unsigned int discard_alignment;
279 unsigned short logical_block_size;
280 unsigned short max_segments;
281 unsigned short max_integrity_segments;
283 unsigned char misaligned;
284 unsigned char discard_misaligned;
285 unsigned char cluster;
286 unsigned char discard_zeroes_data;
287 unsigned char raid_partial_stripes_expensive;
290 struct request_queue {
292 * Together with queue_head for cacheline sharing
294 struct list_head queue_head;
295 struct request *last_merge;
296 struct elevator_queue *elevator;
297 int nr_rqs[2]; /* # allocated [a]sync rqs */
298 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
301 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
302 * is used, root blkg allocates from @q->root_rl and all other
303 * blkgs from their own blkg->rl. Which one to use should be
304 * determined using bio_request_list().
306 struct request_list root_rl;
308 request_fn_proc *request_fn;
309 make_request_fn *make_request_fn;
310 prep_rq_fn *prep_rq_fn;
311 unprep_rq_fn *unprep_rq_fn;
312 softirq_done_fn *softirq_done_fn;
313 rq_timed_out_fn *rq_timed_out_fn;
314 dma_drain_needed_fn *dma_drain_needed;
315 lld_busy_fn *lld_busy_fn;
317 struct blk_mq_ops *mq_ops;
319 unsigned int *mq_map;
322 struct blk_mq_ctx __percpu *queue_ctx;
323 unsigned int nr_queues;
325 /* hw dispatch queues */
326 struct blk_mq_hw_ctx **queue_hw_ctx;
327 unsigned int nr_hw_queues;
330 * Dispatch queue sorting
333 struct request *boundary_rq;
336 * Delayed queue handling
338 struct delayed_work delay_work;
340 struct backing_dev_info *backing_dev_info;
343 * The queue owner gets to use this for whatever they like.
344 * ll_rw_blk doesn't touch it.
349 * various queue flags, see QUEUE_* below
351 unsigned long queue_flags;
354 * ida allocated id for this queue. Used to index queues from
360 * queue needs bounce pages for pages above this limit
365 * protects queue structures from reentrancy. ->__queue_lock should
366 * _never_ be used directly, it is queue private. always use
369 spinlock_t __queue_lock;
370 spinlock_t *queue_lock;
380 struct kobject mq_kobj;
382 #ifdef CONFIG_BLK_DEV_INTEGRITY
383 struct blk_integrity integrity;
384 #endif /* CONFIG_BLK_DEV_INTEGRITY */
389 unsigned int nr_pending;
395 unsigned long nr_requests; /* Max # of requests */
396 unsigned int nr_congestion_on;
397 unsigned int nr_congestion_off;
398 unsigned int nr_batching;
400 unsigned int dma_drain_size;
401 void *dma_drain_buffer;
402 unsigned int dma_pad_mask;
403 unsigned int dma_alignment;
405 struct blk_queue_tag *queue_tags;
406 struct list_head tag_busy_list;
408 unsigned int nr_sorted;
409 unsigned int in_flight[2];
411 * Number of active block driver functions for which blk_drain_queue()
412 * must wait. Must be incremented around functions that unlock the
413 * queue_lock internally, e.g. scsi_request_fn().
415 unsigned int request_fn_active;
417 unsigned int rq_timeout;
418 struct timer_list timeout;
419 struct list_head timeout_list;
421 struct list_head icq_list;
422 #ifdef CONFIG_BLK_CGROUP
423 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
424 struct blkcg_gq *root_blkg;
425 struct list_head blkg_list;
428 struct queue_limits limits;
433 unsigned int sg_timeout;
434 unsigned int sg_reserved_size;
436 #ifdef CONFIG_BLK_DEV_IO_TRACE
437 struct blk_trace *blk_trace;
440 * for flush operations
442 unsigned int flush_flags;
443 unsigned int flush_not_queueable:1;
444 struct blk_flush_queue *fq;
446 struct list_head requeue_list;
447 spinlock_t requeue_lock;
448 struct work_struct requeue_work;
450 struct mutex sysfs_lock;
453 atomic_t mq_freeze_depth;
455 #if defined(CONFIG_BLK_DEV_BSG)
456 bsg_job_fn *bsg_job_fn;
458 struct bsg_class_device bsg_dev;
461 #ifdef CONFIG_BLK_DEV_THROTTLING
463 struct throtl_data *td;
465 struct rcu_head rcu_head;
466 wait_queue_head_t mq_freeze_wq;
467 struct percpu_ref q_usage_counter;
468 struct list_head all_q_node;
470 struct blk_mq_tag_set *tag_set;
471 struct list_head tag_set_list;
472 struct bio_set *bio_split;
474 bool mq_sysfs_init_done;
477 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
478 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
479 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
480 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
481 #define QUEUE_FLAG_DYING 5 /* queue being torn down */
482 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
483 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
484 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
485 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
486 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
487 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
488 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
489 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
490 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
491 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
492 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
493 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
494 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
495 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
496 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
497 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
498 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
499 #define QUEUE_FLAG_POLL 22 /* IO polling enabled if set */
500 #define QUEUE_FLAG_FAST 23 /* fast block device (e.g. ram based) */
502 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
503 (1 << QUEUE_FLAG_STACKABLE) | \
504 (1 << QUEUE_FLAG_SAME_COMP) | \
505 (1 << QUEUE_FLAG_ADD_RANDOM))
507 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
508 (1 << QUEUE_FLAG_STACKABLE) | \
509 (1 << QUEUE_FLAG_SAME_COMP))
511 static inline void queue_lockdep_assert_held(struct request_queue *q)
514 lockdep_assert_held(q->queue_lock);
517 static inline void queue_flag_set_unlocked(unsigned int flag,
518 struct request_queue *q)
520 __set_bit(flag, &q->queue_flags);
523 static inline int queue_flag_test_and_clear(unsigned int flag,
524 struct request_queue *q)
526 queue_lockdep_assert_held(q);
528 if (test_bit(flag, &q->queue_flags)) {
529 __clear_bit(flag, &q->queue_flags);
536 static inline int queue_flag_test_and_set(unsigned int flag,
537 struct request_queue *q)
539 queue_lockdep_assert_held(q);
541 if (!test_bit(flag, &q->queue_flags)) {
542 __set_bit(flag, &q->queue_flags);
549 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
551 queue_lockdep_assert_held(q);
552 __set_bit(flag, &q->queue_flags);
555 static inline void queue_flag_clear_unlocked(unsigned int flag,
556 struct request_queue *q)
558 __clear_bit(flag, &q->queue_flags);
561 static inline int queue_in_flight(struct request_queue *q)
563 return q->in_flight[0] + q->in_flight[1];
566 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
568 queue_lockdep_assert_held(q);
569 __clear_bit(flag, &q->queue_flags);
572 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
573 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
574 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
575 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
576 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
577 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
578 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
579 #define blk_queue_noxmerges(q) \
580 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
581 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
582 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
583 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
584 #define blk_queue_stackable(q) \
585 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
586 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
587 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
588 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
589 #define blk_queue_fast(q) test_bit(QUEUE_FLAG_FAST, &(q)->queue_flags)
591 #define blk_noretry_request(rq) \
592 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
593 REQ_FAILFAST_DRIVER))
595 static inline bool blk_account_rq(struct request *rq)
597 return (rq->cmd_flags & REQ_STARTED) && !blk_rq_is_passthrough(rq);
600 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
601 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
602 /* rq->queuelist of dequeued request must be list_empty() */
603 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
605 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
607 #define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1))
610 * Driver can handle struct request, if it either has an old style
611 * request_fn defined, or is blk-mq based.
613 static inline bool queue_is_rq_based(struct request_queue *q)
615 return q->request_fn || q->mq_ops;
618 static inline unsigned int blk_queue_cluster(struct request_queue *q)
620 return q->limits.cluster;
624 * We regard a request as sync, if either a read or a sync write
626 static inline bool rw_is_sync(unsigned int rw_flags)
628 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
631 static inline bool rq_is_sync(struct request *rq)
633 return rw_is_sync(rq->cmd_flags);
636 static inline bool blk_rl_full(struct request_list *rl, bool sync)
638 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
640 return rl->flags & flag;
643 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
645 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
650 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
652 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
657 static inline bool rq_mergeable(struct request *rq)
659 if (blk_rq_is_passthrough(rq))
662 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
668 static inline bool blk_check_merge_flags(unsigned int flags1,
671 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
674 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
677 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
683 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
685 if (bio_data(a) == bio_data(b))
692 * q->prep_rq_fn return values
694 #define BLKPREP_OK 0 /* serve it */
695 #define BLKPREP_KILL 1 /* fatal error, kill */
696 #define BLKPREP_DEFER 2 /* leave on queue */
698 extern unsigned long blk_max_low_pfn, blk_max_pfn;
701 * standard bounce addresses:
703 * BLK_BOUNCE_HIGH : bounce all highmem pages
704 * BLK_BOUNCE_ANY : don't bounce anything
705 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
708 #if BITS_PER_LONG == 32
709 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
711 #define BLK_BOUNCE_HIGH -1ULL
713 #define BLK_BOUNCE_ANY (-1ULL)
714 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
717 * default timeout for SG_IO if none specified
719 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
720 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
723 extern int init_emergency_isa_pool(void);
724 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
726 static inline int init_emergency_isa_pool(void)
730 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
733 #endif /* CONFIG_MMU */
739 unsigned long offset;
744 struct req_iterator {
745 struct bvec_iter iter;
749 /* This should not be used directly - use rq_for_each_segment */
750 #define for_each_bio(_bio) \
751 for (; _bio; _bio = _bio->bi_next)
752 #define __rq_for_each_bio(_bio, rq) \
754 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
756 #define rq_for_each_segment(bvl, _rq, _iter) \
757 __rq_for_each_bio(_iter.bio, _rq) \
758 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
760 #define rq_iter_last(bvec, _iter) \
761 (_iter.bio->bi_next == NULL && \
762 bio_iter_last(bvec, _iter.iter))
764 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
765 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
767 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
768 extern void rq_flush_dcache_pages(struct request *rq);
770 static inline void rq_flush_dcache_pages(struct request *rq)
775 extern int blk_register_queue(struct gendisk *disk);
776 extern void blk_unregister_queue(struct gendisk *disk);
777 extern blk_qc_t generic_make_request(struct bio *bio);
778 extern void blk_rq_init(struct request_queue *q, struct request *rq);
779 extern void blk_put_request(struct request *);
780 extern void __blk_put_request(struct request_queue *, struct request *);
781 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
782 extern struct request *blk_make_request(struct request_queue *, struct bio *,
784 extern void blk_rq_set_block_pc(struct request *);
785 extern void blk_requeue_request(struct request_queue *, struct request *);
786 extern void blk_add_request_payload(struct request *rq, struct page *page,
788 extern int blk_lld_busy(struct request_queue *q);
789 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
790 struct bio_set *bs, gfp_t gfp_mask,
791 int (*bio_ctr)(struct bio *, struct bio *, void *),
793 extern void blk_rq_unprep_clone(struct request *rq);
794 extern int blk_insert_cloned_request(struct request_queue *q,
796 extern void blk_delay_queue(struct request_queue *, unsigned long);
797 extern void blk_queue_split(struct request_queue *, struct bio **,
799 extern void blk_recount_segments(struct request_queue *, struct bio *);
800 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
801 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
802 unsigned int, void __user *);
803 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
804 unsigned int, void __user *);
805 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
806 struct scsi_ioctl_command __user *);
808 extern void blk_recalc_rq_segments(struct request *rq);
809 extern int blk_queue_enter(struct request_queue *q, gfp_t gfp);
810 extern void blk_queue_exit(struct request_queue *q);
811 extern void blk_start_queue(struct request_queue *q);
812 extern void blk_start_queue_async(struct request_queue *q);
813 extern void blk_stop_queue(struct request_queue *q);
814 extern void blk_sync_queue(struct request_queue *q);
815 extern void __blk_stop_queue(struct request_queue *q);
816 extern void __blk_run_queue(struct request_queue *q);
817 extern void __blk_run_queue_uncond(struct request_queue *q);
818 extern void blk_run_queue(struct request_queue *);
819 extern void blk_run_queue_async(struct request_queue *q);
820 extern int blk_rq_map_user(struct request_queue *, struct request *,
821 struct rq_map_data *, void __user *, unsigned long,
823 extern int blk_rq_unmap_user(struct bio *);
824 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
825 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
826 struct rq_map_data *, const struct iov_iter *,
828 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
829 struct request *, int);
830 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
831 struct request *, int, rq_end_io_fn *);
833 bool blk_poll(struct request_queue *q, blk_qc_t cookie);
835 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
837 return bdev->bd_disk->queue; /* this is never NULL */
841 * blk_rq_pos() : the current sector
842 * blk_rq_bytes() : bytes left in the entire request
843 * blk_rq_cur_bytes() : bytes left in the current segment
844 * blk_rq_err_bytes() : bytes left till the next error boundary
845 * blk_rq_sectors() : sectors left in the entire request
846 * blk_rq_cur_sectors() : sectors left in the current segment
848 static inline sector_t blk_rq_pos(const struct request *rq)
853 static inline unsigned int blk_rq_bytes(const struct request *rq)
855 return rq->__data_len;
858 static inline int blk_rq_cur_bytes(const struct request *rq)
860 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
863 extern unsigned int blk_rq_err_bytes(const struct request *rq);
865 static inline unsigned int blk_rq_sectors(const struct request *rq)
867 return blk_rq_bytes(rq) >> 9;
870 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
872 return blk_rq_cur_bytes(rq) >> 9;
875 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
876 unsigned int cmd_flags)
878 if (unlikely(cmd_flags & REQ_DISCARD))
879 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
881 if (unlikely(cmd_flags & REQ_WRITE_SAME))
882 return q->limits.max_write_same_sectors;
884 return q->limits.max_sectors;
888 * Return maximum size of a request at given offset. Only valid for
889 * file system requests.
891 static inline unsigned int blk_max_size_offset(struct request_queue *q,
894 if (!q->limits.chunk_sectors)
895 return q->limits.max_sectors;
897 return min(q->limits.max_sectors, (unsigned int)(q->limits.chunk_sectors -
898 (offset & (q->limits.chunk_sectors - 1))));
901 static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
903 struct request_queue *q = rq->q;
905 if (blk_rq_is_passthrough(rq))
906 return q->limits.max_hw_sectors;
908 if (!q->limits.chunk_sectors || (rq->cmd_flags & REQ_DISCARD))
909 return blk_queue_get_max_sectors(q, rq->cmd_flags);
911 return min(blk_max_size_offset(q, blk_rq_pos(rq)),
912 blk_queue_get_max_sectors(q, rq->cmd_flags));
915 static inline unsigned int blk_rq_count_bios(struct request *rq)
917 unsigned int nr_bios = 0;
920 __rq_for_each_bio(bio, rq)
927 * Request issue related functions.
929 extern struct request *blk_peek_request(struct request_queue *q);
930 extern void blk_start_request(struct request *rq);
931 extern struct request *blk_fetch_request(struct request_queue *q);
934 * Request completion related functions.
936 * blk_update_request() completes given number of bytes and updates
937 * the request without completing it.
939 * blk_end_request() and friends. __blk_end_request() must be called
940 * with the request queue spinlock acquired.
942 * Several drivers define their own end_request and call
943 * blk_end_request() for parts of the original function.
944 * This prevents code duplication in drivers.
946 extern bool blk_update_request(struct request *rq, int error,
947 unsigned int nr_bytes);
948 extern void blk_finish_request(struct request *rq, int error);
949 extern bool blk_end_request(struct request *rq, int error,
950 unsigned int nr_bytes);
951 extern void blk_end_request_all(struct request *rq, int error);
952 extern bool blk_end_request_cur(struct request *rq, int error);
953 extern bool blk_end_request_err(struct request *rq, int error);
954 extern bool __blk_end_request(struct request *rq, int error,
955 unsigned int nr_bytes);
956 extern void __blk_end_request_all(struct request *rq, int error);
957 extern bool __blk_end_request_cur(struct request *rq, int error);
958 extern bool __blk_end_request_err(struct request *rq, int error);
960 extern void blk_complete_request(struct request *);
961 extern void __blk_complete_request(struct request *);
962 extern void blk_abort_request(struct request *);
963 extern void blk_unprep_request(struct request *);
966 * Access functions for manipulating queue properties
968 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
969 spinlock_t *lock, int node_id);
970 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
971 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
972 request_fn_proc *, spinlock_t *);
973 extern void blk_cleanup_queue(struct request_queue *);
974 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
975 extern void blk_queue_bounce_limit(struct request_queue *, u64);
976 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
977 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
978 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
979 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
980 extern void blk_queue_max_discard_sectors(struct request_queue *q,
981 unsigned int max_discard_sectors);
982 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
983 unsigned int max_write_same_sectors);
984 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
985 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
986 extern void blk_queue_alignment_offset(struct request_queue *q,
987 unsigned int alignment);
988 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
989 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
990 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
991 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
992 extern void blk_set_default_limits(struct queue_limits *lim);
993 extern void blk_set_stacking_limits(struct queue_limits *lim);
994 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
996 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
998 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1000 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1001 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1002 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1003 extern int blk_queue_dma_drain(struct request_queue *q,
1004 dma_drain_needed_fn *dma_drain_needed,
1005 void *buf, unsigned int size);
1006 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1007 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1008 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1009 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1010 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
1011 extern void blk_queue_dma_alignment(struct request_queue *, int);
1012 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1013 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1014 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1015 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1016 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
1017 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1018 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1020 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1021 extern int blk_rq_map_sg_no_cluster
1022 (struct request_queue *, struct request *, struct scatterlist *);
1023 extern void blk_dump_rq_flags(struct request *, char *);
1024 extern long nr_blockdev_pages(void);
1026 bool __must_check blk_get_queue(struct request_queue *);
1027 struct request_queue *blk_alloc_queue(gfp_t);
1028 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1029 extern void blk_put_queue(struct request_queue *);
1030 extern void blk_set_queue_dying(struct request_queue *);
1033 * block layer runtime pm functions
1036 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1037 extern int blk_pre_runtime_suspend(struct request_queue *q);
1038 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1039 extern void blk_pre_runtime_resume(struct request_queue *q);
1040 extern void blk_post_runtime_resume(struct request_queue *q, int err);
1042 static inline void blk_pm_runtime_init(struct request_queue *q,
1043 struct device *dev) {}
1044 static inline int blk_pre_runtime_suspend(struct request_queue *q)
1048 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1049 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1050 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1054 * blk_plug permits building a queue of related requests by holding the I/O
1055 * fragments for a short period. This allows merging of sequential requests
1056 * into single larger request. As the requests are moved from a per-task list to
1057 * the device's request_queue in a batch, this results in improved scalability
1058 * as the lock contention for request_queue lock is reduced.
1060 * It is ok not to disable preemption when adding the request to the plug list
1061 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1062 * the plug list when the task sleeps by itself. For details, please see
1063 * schedule() where blk_schedule_flush_plug() is called.
1066 struct list_head list; /* requests */
1067 struct list_head mq_list; /* blk-mq requests */
1068 struct list_head cb_list; /* md requires an unplug callback */
1070 #define BLK_MAX_REQUEST_COUNT 16
1073 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1074 struct blk_plug_cb {
1075 struct list_head list;
1076 blk_plug_cb_fn callback;
1079 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1080 void *data, int size);
1081 extern void blk_start_plug(struct blk_plug *);
1082 extern void blk_finish_plug(struct blk_plug *);
1083 extern void blk_flush_plug_list(struct blk_plug *, bool);
1085 static inline void blk_flush_plug(struct task_struct *tsk)
1087 struct blk_plug *plug = tsk->plug;
1090 blk_flush_plug_list(plug, false);
1093 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1095 struct blk_plug *plug = tsk->plug;
1098 blk_flush_plug_list(plug, true);
1101 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1103 struct blk_plug *plug = tsk->plug;
1106 (!list_empty(&plug->list) ||
1107 !list_empty(&plug->mq_list) ||
1108 !list_empty(&plug->cb_list));
1114 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1115 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1116 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1117 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
1118 extern void blk_queue_free_tags(struct request_queue *);
1119 extern int blk_queue_resize_tags(struct request_queue *, int);
1120 extern void blk_queue_invalidate_tags(struct request_queue *);
1121 extern struct blk_queue_tag *blk_init_tags(int, int);
1122 extern void blk_free_tags(struct blk_queue_tag *);
1124 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1127 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1129 return bqt->tag_index[tag];
1132 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1134 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1135 extern int blkdev_issue_barrier(struct block_device *, gfp_t, sector_t *);
1136 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1137 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1138 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1139 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1140 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1141 sector_t nr_sects, gfp_t gfp_mask, bool discard);
1142 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1143 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1145 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1146 nr_blocks << (sb->s_blocksize_bits - 9),
1149 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1150 sector_t nr_blocks, gfp_t gfp_mask)
1152 return blkdev_issue_zeroout(sb->s_bdev,
1153 block << (sb->s_blocksize_bits - 9),
1154 nr_blocks << (sb->s_blocksize_bits - 9),
1158 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1160 enum blk_default_limits {
1161 BLK_MAX_SEGMENTS = 128,
1162 BLK_SAFE_MAX_SECTORS = 255,
1163 BLK_DEF_MAX_SECTORS = 2560,
1164 BLK_MAX_SEGMENT_SIZE = 65536,
1165 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1168 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1170 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1172 return q->limits.bounce_pfn;
1175 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1177 return q->limits.seg_boundary_mask;
1180 static inline unsigned long queue_virt_boundary(struct request_queue *q)
1182 return q->limits.virt_boundary_mask;
1185 static inline unsigned int queue_max_sectors(struct request_queue *q)
1187 return q->limits.max_sectors;
1190 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1192 return q->limits.max_hw_sectors;
1195 static inline unsigned short queue_max_segments(struct request_queue *q)
1197 return q->limits.max_segments;
1200 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1202 return q->limits.max_segment_size;
1205 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1209 if (q && q->limits.logical_block_size)
1210 retval = q->limits.logical_block_size;
1215 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1217 return queue_logical_block_size(bdev_get_queue(bdev));
1220 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1222 return q->limits.physical_block_size;
1225 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1227 return queue_physical_block_size(bdev_get_queue(bdev));
1230 static inline unsigned int queue_io_min(struct request_queue *q)
1232 return q->limits.io_min;
1235 static inline int bdev_io_min(struct block_device *bdev)
1237 return queue_io_min(bdev_get_queue(bdev));
1240 static inline unsigned int queue_io_opt(struct request_queue *q)
1242 return q->limits.io_opt;
1245 static inline int bdev_io_opt(struct block_device *bdev)
1247 return queue_io_opt(bdev_get_queue(bdev));
1250 static inline int queue_alignment_offset(struct request_queue *q)
1252 if (q->limits.misaligned)
1255 return q->limits.alignment_offset;
1258 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1260 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1261 unsigned int alignment = sector_div(sector, granularity >> 9) << 9;
1263 return (granularity + lim->alignment_offset - alignment) % granularity;
1266 static inline int bdev_alignment_offset(struct block_device *bdev)
1268 struct request_queue *q = bdev_get_queue(bdev);
1270 if (q->limits.misaligned)
1273 if (bdev != bdev->bd_contains)
1274 return bdev->bd_part->alignment_offset;
1276 return q->limits.alignment_offset;
1279 static inline int queue_discard_alignment(struct request_queue *q)
1281 if (q->limits.discard_misaligned)
1284 return q->limits.discard_alignment;
1287 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1289 unsigned int alignment, granularity, offset;
1291 if (!lim->max_discard_sectors)
1294 /* Why are these in bytes, not sectors? */
1295 alignment = lim->discard_alignment >> 9;
1296 granularity = lim->discard_granularity >> 9;
1300 /* Offset of the partition start in 'granularity' sectors */
1301 offset = sector_div(sector, granularity);
1303 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1304 offset = (granularity + alignment - offset) % granularity;
1306 /* Turn it back into bytes, gaah */
1310 static inline int bdev_discard_alignment(struct block_device *bdev)
1312 struct request_queue *q = bdev_get_queue(bdev);
1314 if (bdev != bdev->bd_contains)
1315 return bdev->bd_part->discard_alignment;
1317 return q->limits.discard_alignment;
1320 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1322 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1328 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1330 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1333 static inline unsigned int bdev_write_same(struct block_device *bdev)
1335 struct request_queue *q = bdev_get_queue(bdev);
1338 return q->limits.max_write_same_sectors;
1343 static inline int queue_dma_alignment(struct request_queue *q)
1345 return q ? q->dma_alignment : 511;
1348 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1351 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1352 return !(addr & alignment) && !(len & alignment);
1355 /* assumes size > 256 */
1356 static inline unsigned int blksize_bits(unsigned int size)
1358 unsigned int bits = 8;
1362 } while (size > 256);
1366 static inline unsigned int block_size(struct block_device *bdev)
1368 return bdev->bd_block_size;
1371 static inline bool queue_flush_queueable(struct request_queue *q)
1373 return !q->flush_not_queueable;
1376 typedef struct {struct page *v;} Sector;
1378 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1380 static inline void put_dev_sector(Sector p)
1382 page_cache_release(p.v);
1385 static inline bool __bvec_gap_to_prev(struct request_queue *q,
1386 struct bio_vec *bprv, unsigned int offset)
1389 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
1393 * Check if adding a bio_vec after bprv with offset would create a gap in
1394 * the SG list. Most drivers don't care about this, but some do.
1396 static inline bool bvec_gap_to_prev(struct request_queue *q,
1397 struct bio_vec *bprv, unsigned int offset)
1399 if (!queue_virt_boundary(q))
1401 return __bvec_gap_to_prev(q, bprv, offset);
1404 static inline bool bio_will_gap(struct request_queue *q, struct bio *prev,
1407 if (bio_has_data(prev) && queue_virt_boundary(q)) {
1408 struct bio_vec pb, nb;
1410 bio_get_last_bvec(prev, &pb);
1411 bio_get_first_bvec(next, &nb);
1413 return __bvec_gap_to_prev(q, &pb, nb.bv_offset);
1419 static inline bool req_gap_back_merge(struct request *req, struct bio *bio)
1421 return bio_will_gap(req->q, req->biotail, bio);
1424 static inline bool req_gap_front_merge(struct request *req, struct bio *bio)
1426 return bio_will_gap(req->q, bio, req->bio);
1430 int kblockd_schedule_work(struct work_struct *work);
1431 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
1432 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1434 #ifdef CONFIG_BLK_CGROUP
1436 * This should not be using sched_clock(). A real patch is in progress
1437 * to fix this up, until that is in place we need to disable preemption
1438 * around sched_clock() in this function and set_io_start_time_ns().
1440 static inline void set_start_time_ns(struct request *req)
1443 req->start_time_ns = sched_clock();
1447 static inline void set_io_start_time_ns(struct request *req)
1450 req->io_start_time_ns = sched_clock();
1454 static inline uint64_t rq_start_time_ns(struct request *req)
1456 return req->start_time_ns;
1459 static inline uint64_t rq_io_start_time_ns(struct request *req)
1461 return req->io_start_time_ns;
1464 static inline void set_start_time_ns(struct request *req) {}
1465 static inline void set_io_start_time_ns(struct request *req) {}
1466 static inline uint64_t rq_start_time_ns(struct request *req)
1470 static inline uint64_t rq_io_start_time_ns(struct request *req)
1476 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1477 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1478 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1479 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1481 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1483 enum blk_integrity_flags {
1484 BLK_INTEGRITY_VERIFY = 1 << 0,
1485 BLK_INTEGRITY_GENERATE = 1 << 1,
1486 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2,
1487 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3,
1490 struct blk_integrity_iter {
1494 unsigned int data_size;
1495 unsigned short interval;
1496 const char *disk_name;
1499 typedef int (integrity_processing_fn) (struct blk_integrity_iter *);
1501 struct blk_integrity_profile {
1502 integrity_processing_fn *generate_fn;
1503 integrity_processing_fn *verify_fn;
1507 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1508 extern void blk_integrity_unregister(struct gendisk *);
1509 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1510 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1511 struct scatterlist *);
1512 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1513 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1515 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1518 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1520 struct blk_integrity *bi = &disk->queue->integrity;
1529 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1531 return blk_get_integrity(bdev->bd_disk);
1534 static inline bool blk_integrity_rq(struct request *rq)
1536 return rq->cmd_flags & REQ_INTEGRITY;
1539 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1542 q->limits.max_integrity_segments = segs;
1545 static inline unsigned short
1546 queue_max_integrity_segments(struct request_queue *q)
1548 return q->limits.max_integrity_segments;
1551 static inline bool integrity_req_gap_back_merge(struct request *req,
1554 struct bio_integrity_payload *bip = bio_integrity(req->bio);
1555 struct bio_integrity_payload *bip_next = bio_integrity(next);
1557 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
1558 bip_next->bip_vec[0].bv_offset);
1561 static inline bool integrity_req_gap_front_merge(struct request *req,
1564 struct bio_integrity_payload *bip = bio_integrity(bio);
1565 struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
1567 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
1568 bip_next->bip_vec[0].bv_offset);
1571 #else /* CONFIG_BLK_DEV_INTEGRITY */
1574 struct block_device;
1576 struct blk_integrity;
1578 static inline int blk_integrity_rq(struct request *rq)
1582 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1587 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1589 struct scatterlist *s)
1593 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1597 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1601 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1605 static inline void blk_integrity_register(struct gendisk *d,
1606 struct blk_integrity *b)
1609 static inline void blk_integrity_unregister(struct gendisk *d)
1612 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1616 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1620 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1626 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1633 static inline bool integrity_req_gap_back_merge(struct request *req,
1638 static inline bool integrity_req_gap_front_merge(struct request *req,
1644 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1646 struct block_device_operations {
1647 int (*open) (struct block_device *, fmode_t);
1648 void (*release) (struct gendisk *, fmode_t);
1649 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
1650 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1651 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1652 long (*direct_access)(struct block_device *, sector_t, void __pmem **,
1653 unsigned long *pfn);
1654 unsigned int (*check_events) (struct gendisk *disk,
1655 unsigned int clearing);
1656 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1657 int (*media_changed) (struct gendisk *);
1658 void (*unlock_native_capacity) (struct gendisk *);
1659 int (*revalidate_disk) (struct gendisk *);
1660 int (*getgeo)(struct block_device *, struct hd_geometry *);
1661 /* this callback is with swap_lock and sometimes page table lock held */
1662 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1663 struct module *owner;
1664 const struct pr_ops *pr_ops;
1667 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1669 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1670 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1671 struct writeback_control *);
1672 extern long bdev_direct_access(struct block_device *, sector_t,
1673 void __pmem **addr, unsigned long *pfn, long size);
1676 * X-axis for IO latency histogram support.
1678 static const u_int64_t latency_x_axis_us[] = {
1704 #define BLK_IO_LAT_HIST_DISABLE 0
1705 #define BLK_IO_LAT_HIST_ENABLE 1
1706 #define BLK_IO_LAT_HIST_ZERO 2
1708 struct io_latency_state {
1709 u_int64_t latency_y_axis[ARRAY_SIZE(latency_x_axis_us) + 1];
1710 u_int64_t latency_elems;
1711 u_int64_t latency_sum;
1715 blk_update_latency_hist(struct io_latency_state *s, u_int64_t delta_us)
1719 for (i = 0; i < ARRAY_SIZE(latency_x_axis_us); i++)
1720 if (delta_us < (u_int64_t)latency_x_axis_us[i])
1722 s->latency_y_axis[i]++;
1724 s->latency_sum += delta_us;
1727 ssize_t blk_latency_hist_show(char* name, struct io_latency_state *s,
1728 char *buf, int buf_size);
1730 #else /* CONFIG_BLOCK */
1732 struct block_device;
1735 * stubs for when the block layer is configured out
1737 #define buffer_heads_over_limit 0
1739 static inline long nr_blockdev_pages(void)
1747 static inline void blk_start_plug(struct blk_plug *plug)
1751 static inline void blk_finish_plug(struct blk_plug *plug)
1755 static inline void blk_flush_plug(struct task_struct *task)
1759 static inline void blk_schedule_flush_plug(struct task_struct *task)
1764 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1769 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1770 sector_t *error_sector)
1775 #endif /* CONFIG_BLOCK */