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 unsigned short req_get_ioprio(struct request *req)
210 #include <linux/elevator.h>
212 struct blk_queue_ctx;
214 typedef void (request_fn_proc) (struct request_queue *q);
215 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
216 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
217 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
220 typedef void (softirq_done_fn)(struct request *);
221 typedef int (dma_drain_needed_fn)(struct request *);
222 typedef int (lld_busy_fn) (struct request_queue *q);
223 typedef int (bsg_job_fn) (struct bsg_job *);
225 enum blk_eh_timer_return {
231 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
233 enum blk_queue_state {
238 struct blk_queue_tag {
239 struct request **tag_index; /* map of busy tags */
240 unsigned long *tag_map; /* bit map of free/busy tags */
241 int busy; /* current depth */
242 int max_depth; /* what we will send to device */
243 int real_max_depth; /* what the array can hold */
244 atomic_t refcnt; /* map can be shared */
245 int alloc_policy; /* tag allocation policy */
246 int next_tag; /* next tag */
248 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
249 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
251 #define BLK_SCSI_MAX_CMDS (256)
252 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
254 struct queue_limits {
255 unsigned long bounce_pfn;
256 unsigned long seg_boundary_mask;
257 unsigned long virt_boundary_mask;
259 unsigned int max_hw_sectors;
260 unsigned int max_dev_sectors;
261 unsigned int chunk_sectors;
262 unsigned int max_sectors;
263 unsigned int max_segment_size;
264 unsigned int physical_block_size;
265 unsigned int alignment_offset;
268 unsigned int max_discard_sectors;
269 unsigned int max_hw_discard_sectors;
270 unsigned int max_write_same_sectors;
271 unsigned int discard_granularity;
272 unsigned int discard_alignment;
274 unsigned short logical_block_size;
275 unsigned short max_segments;
276 unsigned short max_integrity_segments;
278 unsigned char misaligned;
279 unsigned char discard_misaligned;
280 unsigned char cluster;
281 unsigned char discard_zeroes_data;
282 unsigned char raid_partial_stripes_expensive;
285 struct request_queue {
287 * Together with queue_head for cacheline sharing
289 struct list_head queue_head;
290 struct request *last_merge;
291 struct elevator_queue *elevator;
292 int nr_rqs[2]; /* # allocated [a]sync rqs */
293 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
296 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
297 * is used, root blkg allocates from @q->root_rl and all other
298 * blkgs from their own blkg->rl. Which one to use should be
299 * determined using bio_request_list().
301 struct request_list root_rl;
303 request_fn_proc *request_fn;
304 make_request_fn *make_request_fn;
305 prep_rq_fn *prep_rq_fn;
306 unprep_rq_fn *unprep_rq_fn;
307 softirq_done_fn *softirq_done_fn;
308 rq_timed_out_fn *rq_timed_out_fn;
309 dma_drain_needed_fn *dma_drain_needed;
310 lld_busy_fn *lld_busy_fn;
312 struct blk_mq_ops *mq_ops;
314 unsigned int *mq_map;
317 struct blk_mq_ctx __percpu *queue_ctx;
318 unsigned int nr_queues;
320 /* hw dispatch queues */
321 struct blk_mq_hw_ctx **queue_hw_ctx;
322 unsigned int nr_hw_queues;
325 * Dispatch queue sorting
328 struct request *boundary_rq;
331 * Delayed queue handling
333 struct delayed_work delay_work;
335 struct backing_dev_info backing_dev_info;
338 * The queue owner gets to use this for whatever they like.
339 * ll_rw_blk doesn't touch it.
344 * various queue flags, see QUEUE_* below
346 unsigned long queue_flags;
349 * ida allocated id for this queue. Used to index queues from
355 * queue needs bounce pages for pages above this limit
360 * protects queue structures from reentrancy. ->__queue_lock should
361 * _never_ be used directly, it is queue private. always use
364 spinlock_t __queue_lock;
365 spinlock_t *queue_lock;
375 struct kobject mq_kobj;
377 #ifdef CONFIG_BLK_DEV_INTEGRITY
378 struct blk_integrity integrity;
379 #endif /* CONFIG_BLK_DEV_INTEGRITY */
384 unsigned int nr_pending;
390 unsigned long nr_requests; /* Max # of requests */
391 unsigned int nr_congestion_on;
392 unsigned int nr_congestion_off;
393 unsigned int nr_batching;
395 unsigned int dma_drain_size;
396 void *dma_drain_buffer;
397 unsigned int dma_pad_mask;
398 unsigned int dma_alignment;
400 struct blk_queue_tag *queue_tags;
401 struct list_head tag_busy_list;
403 unsigned int nr_sorted;
404 unsigned int in_flight[2];
406 * Number of active block driver functions for which blk_drain_queue()
407 * must wait. Must be incremented around functions that unlock the
408 * queue_lock internally, e.g. scsi_request_fn().
410 unsigned int request_fn_active;
412 unsigned int rq_timeout;
413 struct timer_list timeout;
414 struct list_head timeout_list;
416 struct list_head icq_list;
417 #ifdef CONFIG_BLK_CGROUP
418 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
419 struct blkcg_gq *root_blkg;
420 struct list_head blkg_list;
423 struct queue_limits limits;
428 unsigned int sg_timeout;
429 unsigned int sg_reserved_size;
431 #ifdef CONFIG_BLK_DEV_IO_TRACE
432 struct blk_trace *blk_trace;
435 * for flush operations
437 unsigned int flush_flags;
438 unsigned int flush_not_queueable:1;
439 struct blk_flush_queue *fq;
441 struct list_head requeue_list;
442 spinlock_t requeue_lock;
443 struct work_struct requeue_work;
445 struct mutex sysfs_lock;
448 atomic_t mq_freeze_depth;
450 #if defined(CONFIG_BLK_DEV_BSG)
451 bsg_job_fn *bsg_job_fn;
453 struct bsg_class_device bsg_dev;
456 #ifdef CONFIG_BLK_DEV_THROTTLING
458 struct throtl_data *td;
460 struct rcu_head rcu_head;
461 wait_queue_head_t mq_freeze_wq;
462 struct percpu_ref q_usage_counter;
463 struct list_head all_q_node;
465 struct blk_mq_tag_set *tag_set;
466 struct list_head tag_set_list;
467 struct bio_set *bio_split;
469 bool mq_sysfs_init_done;
472 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
473 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
474 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
475 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
476 #define QUEUE_FLAG_DYING 5 /* queue being torn down */
477 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
478 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
479 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
480 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
481 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
482 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
483 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
484 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
485 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
486 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
487 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
488 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
489 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
490 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
491 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
492 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
493 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
494 #define QUEUE_FLAG_POLL 22 /* IO polling enabled if set */
496 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
497 (1 << QUEUE_FLAG_STACKABLE) | \
498 (1 << QUEUE_FLAG_SAME_COMP) | \
499 (1 << QUEUE_FLAG_ADD_RANDOM))
501 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
502 (1 << QUEUE_FLAG_STACKABLE) | \
503 (1 << QUEUE_FLAG_SAME_COMP))
505 static inline void queue_lockdep_assert_held(struct request_queue *q)
508 lockdep_assert_held(q->queue_lock);
511 static inline void queue_flag_set_unlocked(unsigned int flag,
512 struct request_queue *q)
514 __set_bit(flag, &q->queue_flags);
517 static inline int queue_flag_test_and_clear(unsigned int flag,
518 struct request_queue *q)
520 queue_lockdep_assert_held(q);
522 if (test_bit(flag, &q->queue_flags)) {
523 __clear_bit(flag, &q->queue_flags);
530 static inline int queue_flag_test_and_set(unsigned int flag,
531 struct request_queue *q)
533 queue_lockdep_assert_held(q);
535 if (!test_bit(flag, &q->queue_flags)) {
536 __set_bit(flag, &q->queue_flags);
543 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
545 queue_lockdep_assert_held(q);
546 __set_bit(flag, &q->queue_flags);
549 static inline void queue_flag_clear_unlocked(unsigned int flag,
550 struct request_queue *q)
552 __clear_bit(flag, &q->queue_flags);
555 static inline int queue_in_flight(struct request_queue *q)
557 return q->in_flight[0] + q->in_flight[1];
560 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
562 queue_lockdep_assert_held(q);
563 __clear_bit(flag, &q->queue_flags);
566 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
567 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
568 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
569 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
570 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
571 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
572 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
573 #define blk_queue_noxmerges(q) \
574 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
575 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
576 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
577 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
578 #define blk_queue_stackable(q) \
579 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
580 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
581 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
582 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
584 #define blk_noretry_request(rq) \
585 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
586 REQ_FAILFAST_DRIVER))
588 #define blk_account_rq(rq) \
589 (((rq)->cmd_flags & REQ_STARTED) && \
590 ((rq)->cmd_type == REQ_TYPE_FS))
592 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
593 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
594 /* rq->queuelist of dequeued request must be list_empty() */
595 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
597 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
599 #define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1))
602 * Driver can handle struct request, if it either has an old style
603 * request_fn defined, or is blk-mq based.
605 static inline bool queue_is_rq_based(struct request_queue *q)
607 return q->request_fn || q->mq_ops;
610 static inline unsigned int blk_queue_cluster(struct request_queue *q)
612 return q->limits.cluster;
616 * We regard a request as sync, if either a read or a sync write
618 static inline bool rw_is_sync(unsigned int rw_flags)
620 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
623 static inline bool rq_is_sync(struct request *rq)
625 return rw_is_sync(rq->cmd_flags);
628 static inline bool blk_rl_full(struct request_list *rl, bool sync)
630 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
632 return rl->flags & flag;
635 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
637 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
642 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
644 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
649 static inline bool rq_mergeable(struct request *rq)
651 if (rq->cmd_type != REQ_TYPE_FS)
654 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
660 static inline bool blk_check_merge_flags(unsigned int flags1,
663 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
666 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
669 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
675 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
677 if (bio_data(a) == bio_data(b))
684 * q->prep_rq_fn return values
686 #define BLKPREP_OK 0 /* serve it */
687 #define BLKPREP_KILL 1 /* fatal error, kill */
688 #define BLKPREP_DEFER 2 /* leave on queue */
690 extern unsigned long blk_max_low_pfn, blk_max_pfn;
693 * standard bounce addresses:
695 * BLK_BOUNCE_HIGH : bounce all highmem pages
696 * BLK_BOUNCE_ANY : don't bounce anything
697 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
700 #if BITS_PER_LONG == 32
701 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
703 #define BLK_BOUNCE_HIGH -1ULL
705 #define BLK_BOUNCE_ANY (-1ULL)
706 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
709 * default timeout for SG_IO if none specified
711 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
712 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
715 extern int init_emergency_isa_pool(void);
716 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
718 static inline int init_emergency_isa_pool(void)
722 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
725 #endif /* CONFIG_MMU */
731 unsigned long offset;
736 struct req_iterator {
737 struct bvec_iter iter;
741 /* This should not be used directly - use rq_for_each_segment */
742 #define for_each_bio(_bio) \
743 for (; _bio; _bio = _bio->bi_next)
744 #define __rq_for_each_bio(_bio, rq) \
746 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
748 #define rq_for_each_segment(bvl, _rq, _iter) \
749 __rq_for_each_bio(_iter.bio, _rq) \
750 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
752 #define rq_iter_last(bvec, _iter) \
753 (_iter.bio->bi_next == NULL && \
754 bio_iter_last(bvec, _iter.iter))
756 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
757 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
759 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
760 extern void rq_flush_dcache_pages(struct request *rq);
762 static inline void rq_flush_dcache_pages(struct request *rq)
767 extern int blk_register_queue(struct gendisk *disk);
768 extern void blk_unregister_queue(struct gendisk *disk);
769 extern blk_qc_t generic_make_request(struct bio *bio);
770 extern void blk_rq_init(struct request_queue *q, struct request *rq);
771 extern void blk_put_request(struct request *);
772 extern void __blk_put_request(struct request_queue *, struct request *);
773 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
774 extern struct request *blk_make_request(struct request_queue *, struct bio *,
776 extern void blk_rq_set_block_pc(struct request *);
777 extern void blk_requeue_request(struct request_queue *, struct request *);
778 extern void blk_add_request_payload(struct request *rq, struct page *page,
780 extern int blk_lld_busy(struct request_queue *q);
781 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
782 struct bio_set *bs, gfp_t gfp_mask,
783 int (*bio_ctr)(struct bio *, struct bio *, void *),
785 extern void blk_rq_unprep_clone(struct request *rq);
786 extern int blk_insert_cloned_request(struct request_queue *q,
788 extern void blk_delay_queue(struct request_queue *, unsigned long);
789 extern void blk_queue_split(struct request_queue *, struct bio **,
791 extern void blk_recount_segments(struct request_queue *, struct bio *);
792 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
793 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
794 unsigned int, void __user *);
795 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
796 unsigned int, void __user *);
797 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
798 struct scsi_ioctl_command __user *);
800 extern int blk_queue_enter(struct request_queue *q, gfp_t gfp);
801 extern void blk_queue_exit(struct request_queue *q);
802 extern void blk_start_queue(struct request_queue *q);
803 extern void blk_start_queue_async(struct request_queue *q);
804 extern void blk_stop_queue(struct request_queue *q);
805 extern void blk_sync_queue(struct request_queue *q);
806 extern void __blk_stop_queue(struct request_queue *q);
807 extern void __blk_run_queue(struct request_queue *q);
808 extern void __blk_run_queue_uncond(struct request_queue *q);
809 extern void blk_run_queue(struct request_queue *);
810 extern void blk_run_queue_async(struct request_queue *q);
811 extern int blk_rq_map_user(struct request_queue *, struct request *,
812 struct rq_map_data *, void __user *, unsigned long,
814 extern int blk_rq_unmap_user(struct bio *);
815 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
816 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
817 struct rq_map_data *, const struct iov_iter *,
819 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
820 struct request *, int);
821 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
822 struct request *, int, rq_end_io_fn *);
824 bool blk_poll(struct request_queue *q, blk_qc_t cookie);
826 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
828 return bdev->bd_disk->queue; /* this is never NULL */
832 * blk_rq_pos() : the current sector
833 * blk_rq_bytes() : bytes left in the entire request
834 * blk_rq_cur_bytes() : bytes left in the current segment
835 * blk_rq_err_bytes() : bytes left till the next error boundary
836 * blk_rq_sectors() : sectors left in the entire request
837 * blk_rq_cur_sectors() : sectors left in the current segment
839 static inline sector_t blk_rq_pos(const struct request *rq)
844 static inline unsigned int blk_rq_bytes(const struct request *rq)
846 return rq->__data_len;
849 static inline int blk_rq_cur_bytes(const struct request *rq)
851 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
854 extern unsigned int blk_rq_err_bytes(const struct request *rq);
856 static inline unsigned int blk_rq_sectors(const struct request *rq)
858 return blk_rq_bytes(rq) >> 9;
861 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
863 return blk_rq_cur_bytes(rq) >> 9;
866 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
867 unsigned int cmd_flags)
869 if (unlikely(cmd_flags & REQ_DISCARD))
870 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
872 if (unlikely(cmd_flags & REQ_WRITE_SAME))
873 return q->limits.max_write_same_sectors;
875 return q->limits.max_sectors;
879 * Return maximum size of a request at given offset. Only valid for
880 * file system requests.
882 static inline unsigned int blk_max_size_offset(struct request_queue *q,
885 if (!q->limits.chunk_sectors)
886 return q->limits.max_sectors;
888 return q->limits.chunk_sectors -
889 (offset & (q->limits.chunk_sectors - 1));
892 static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
894 struct request_queue *q = rq->q;
896 if (unlikely(rq->cmd_type != REQ_TYPE_FS))
897 return q->limits.max_hw_sectors;
899 if (!q->limits.chunk_sectors || (rq->cmd_flags & REQ_DISCARD))
900 return blk_queue_get_max_sectors(q, rq->cmd_flags);
902 return min(blk_max_size_offset(q, blk_rq_pos(rq)),
903 blk_queue_get_max_sectors(q, rq->cmd_flags));
906 static inline unsigned int blk_rq_count_bios(struct request *rq)
908 unsigned int nr_bios = 0;
911 __rq_for_each_bio(bio, rq)
918 * Request issue related functions.
920 extern struct request *blk_peek_request(struct request_queue *q);
921 extern void blk_start_request(struct request *rq);
922 extern struct request *blk_fetch_request(struct request_queue *q);
925 * Request completion related functions.
927 * blk_update_request() completes given number of bytes and updates
928 * the request without completing it.
930 * blk_end_request() and friends. __blk_end_request() must be called
931 * with the request queue spinlock acquired.
933 * Several drivers define their own end_request and call
934 * blk_end_request() for parts of the original function.
935 * This prevents code duplication in drivers.
937 extern bool blk_update_request(struct request *rq, int error,
938 unsigned int nr_bytes);
939 extern void blk_finish_request(struct request *rq, int error);
940 extern bool blk_end_request(struct request *rq, int error,
941 unsigned int nr_bytes);
942 extern void blk_end_request_all(struct request *rq, int error);
943 extern bool blk_end_request_cur(struct request *rq, int error);
944 extern bool blk_end_request_err(struct request *rq, int error);
945 extern bool __blk_end_request(struct request *rq, int error,
946 unsigned int nr_bytes);
947 extern void __blk_end_request_all(struct request *rq, int error);
948 extern bool __blk_end_request_cur(struct request *rq, int error);
949 extern bool __blk_end_request_err(struct request *rq, int error);
951 extern void blk_complete_request(struct request *);
952 extern void __blk_complete_request(struct request *);
953 extern void blk_abort_request(struct request *);
954 extern void blk_unprep_request(struct request *);
957 * Access functions for manipulating queue properties
959 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
960 spinlock_t *lock, int node_id);
961 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
962 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
963 request_fn_proc *, spinlock_t *);
964 extern void blk_cleanup_queue(struct request_queue *);
965 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
966 extern void blk_queue_bounce_limit(struct request_queue *, u64);
967 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
968 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
969 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
970 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
971 extern void blk_queue_max_discard_sectors(struct request_queue *q,
972 unsigned int max_discard_sectors);
973 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
974 unsigned int max_write_same_sectors);
975 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
976 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
977 extern void blk_queue_alignment_offset(struct request_queue *q,
978 unsigned int alignment);
979 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
980 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
981 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
982 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
983 extern void blk_set_default_limits(struct queue_limits *lim);
984 extern void blk_set_stacking_limits(struct queue_limits *lim);
985 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
987 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
989 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
991 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
992 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
993 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
994 extern int blk_queue_dma_drain(struct request_queue *q,
995 dma_drain_needed_fn *dma_drain_needed,
996 void *buf, unsigned int size);
997 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
998 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
999 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
1000 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1001 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
1002 extern void blk_queue_dma_alignment(struct request_queue *, int);
1003 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1004 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1005 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1006 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1007 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
1008 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1009 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1011 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1012 extern void blk_dump_rq_flags(struct request *, char *);
1013 extern long nr_blockdev_pages(void);
1015 bool __must_check blk_get_queue(struct request_queue *);
1016 struct request_queue *blk_alloc_queue(gfp_t);
1017 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1018 extern void blk_put_queue(struct request_queue *);
1019 extern void blk_set_queue_dying(struct request_queue *);
1022 * block layer runtime pm functions
1025 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1026 extern int blk_pre_runtime_suspend(struct request_queue *q);
1027 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1028 extern void blk_pre_runtime_resume(struct request_queue *q);
1029 extern void blk_post_runtime_resume(struct request_queue *q, int err);
1031 static inline void blk_pm_runtime_init(struct request_queue *q,
1032 struct device *dev) {}
1033 static inline int blk_pre_runtime_suspend(struct request_queue *q)
1037 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1038 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1039 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1043 * blk_plug permits building a queue of related requests by holding the I/O
1044 * fragments for a short period. This allows merging of sequential requests
1045 * into single larger request. As the requests are moved from a per-task list to
1046 * the device's request_queue in a batch, this results in improved scalability
1047 * as the lock contention for request_queue lock is reduced.
1049 * It is ok not to disable preemption when adding the request to the plug list
1050 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1051 * the plug list when the task sleeps by itself. For details, please see
1052 * schedule() where blk_schedule_flush_plug() is called.
1055 struct list_head list; /* requests */
1056 struct list_head mq_list; /* blk-mq requests */
1057 struct list_head cb_list; /* md requires an unplug callback */
1059 #define BLK_MAX_REQUEST_COUNT 16
1062 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1063 struct blk_plug_cb {
1064 struct list_head list;
1065 blk_plug_cb_fn callback;
1068 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1069 void *data, int size);
1070 extern void blk_start_plug(struct blk_plug *);
1071 extern void blk_finish_plug(struct blk_plug *);
1072 extern void blk_flush_plug_list(struct blk_plug *, bool);
1074 static inline void blk_flush_plug(struct task_struct *tsk)
1076 struct blk_plug *plug = tsk->plug;
1079 blk_flush_plug_list(plug, false);
1082 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1084 struct blk_plug *plug = tsk->plug;
1087 blk_flush_plug_list(plug, true);
1090 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1092 struct blk_plug *plug = tsk->plug;
1095 (!list_empty(&plug->list) ||
1096 !list_empty(&plug->mq_list) ||
1097 !list_empty(&plug->cb_list));
1103 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1104 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1105 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1106 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
1107 extern void blk_queue_free_tags(struct request_queue *);
1108 extern int blk_queue_resize_tags(struct request_queue *, int);
1109 extern void blk_queue_invalidate_tags(struct request_queue *);
1110 extern struct blk_queue_tag *blk_init_tags(int, int);
1111 extern void blk_free_tags(struct blk_queue_tag *);
1113 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1116 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1118 return bqt->tag_index[tag];
1121 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1123 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1124 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1125 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1126 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1127 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1128 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1129 sector_t nr_sects, gfp_t gfp_mask, bool discard);
1130 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1131 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1133 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1134 nr_blocks << (sb->s_blocksize_bits - 9),
1137 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1138 sector_t nr_blocks, gfp_t gfp_mask)
1140 return blkdev_issue_zeroout(sb->s_bdev,
1141 block << (sb->s_blocksize_bits - 9),
1142 nr_blocks << (sb->s_blocksize_bits - 9),
1146 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1148 enum blk_default_limits {
1149 BLK_MAX_SEGMENTS = 128,
1150 BLK_SAFE_MAX_SECTORS = 255,
1151 BLK_DEF_MAX_SECTORS = 2560,
1152 BLK_MAX_SEGMENT_SIZE = 65536,
1153 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1156 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1158 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1160 return q->limits.bounce_pfn;
1163 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1165 return q->limits.seg_boundary_mask;
1168 static inline unsigned long queue_virt_boundary(struct request_queue *q)
1170 return q->limits.virt_boundary_mask;
1173 static inline unsigned int queue_max_sectors(struct request_queue *q)
1175 return q->limits.max_sectors;
1178 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1180 return q->limits.max_hw_sectors;
1183 static inline unsigned short queue_max_segments(struct request_queue *q)
1185 return q->limits.max_segments;
1188 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1190 return q->limits.max_segment_size;
1193 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1197 if (q && q->limits.logical_block_size)
1198 retval = q->limits.logical_block_size;
1203 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1205 return queue_logical_block_size(bdev_get_queue(bdev));
1208 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1210 return q->limits.physical_block_size;
1213 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1215 return queue_physical_block_size(bdev_get_queue(bdev));
1218 static inline unsigned int queue_io_min(struct request_queue *q)
1220 return q->limits.io_min;
1223 static inline int bdev_io_min(struct block_device *bdev)
1225 return queue_io_min(bdev_get_queue(bdev));
1228 static inline unsigned int queue_io_opt(struct request_queue *q)
1230 return q->limits.io_opt;
1233 static inline int bdev_io_opt(struct block_device *bdev)
1235 return queue_io_opt(bdev_get_queue(bdev));
1238 static inline int queue_alignment_offset(struct request_queue *q)
1240 if (q->limits.misaligned)
1243 return q->limits.alignment_offset;
1246 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1248 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1249 unsigned int alignment = sector_div(sector, granularity >> 9) << 9;
1251 return (granularity + lim->alignment_offset - alignment) % granularity;
1254 static inline int bdev_alignment_offset(struct block_device *bdev)
1256 struct request_queue *q = bdev_get_queue(bdev);
1258 if (q->limits.misaligned)
1261 if (bdev != bdev->bd_contains)
1262 return bdev->bd_part->alignment_offset;
1264 return q->limits.alignment_offset;
1267 static inline int queue_discard_alignment(struct request_queue *q)
1269 if (q->limits.discard_misaligned)
1272 return q->limits.discard_alignment;
1275 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1277 unsigned int alignment, granularity, offset;
1279 if (!lim->max_discard_sectors)
1282 /* Why are these in bytes, not sectors? */
1283 alignment = lim->discard_alignment >> 9;
1284 granularity = lim->discard_granularity >> 9;
1288 /* Offset of the partition start in 'granularity' sectors */
1289 offset = sector_div(sector, granularity);
1291 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1292 offset = (granularity + alignment - offset) % granularity;
1294 /* Turn it back into bytes, gaah */
1298 static inline int bdev_discard_alignment(struct block_device *bdev)
1300 struct request_queue *q = bdev_get_queue(bdev);
1302 if (bdev != bdev->bd_contains)
1303 return bdev->bd_part->discard_alignment;
1305 return q->limits.discard_alignment;
1308 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1310 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1316 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1318 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1321 static inline unsigned int bdev_write_same(struct block_device *bdev)
1323 struct request_queue *q = bdev_get_queue(bdev);
1326 return q->limits.max_write_same_sectors;
1331 static inline int queue_dma_alignment(struct request_queue *q)
1333 return q ? q->dma_alignment : 511;
1336 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1339 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1340 return !(addr & alignment) && !(len & alignment);
1343 /* assumes size > 256 */
1344 static inline unsigned int blksize_bits(unsigned int size)
1346 unsigned int bits = 8;
1350 } while (size > 256);
1354 static inline unsigned int block_size(struct block_device *bdev)
1356 return bdev->bd_block_size;
1359 static inline bool queue_flush_queueable(struct request_queue *q)
1361 return !q->flush_not_queueable;
1364 typedef struct {struct page *v;} Sector;
1366 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1368 static inline void put_dev_sector(Sector p)
1370 page_cache_release(p.v);
1373 static inline bool __bvec_gap_to_prev(struct request_queue *q,
1374 struct bio_vec *bprv, unsigned int offset)
1377 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
1381 * Check if adding a bio_vec after bprv with offset would create a gap in
1382 * the SG list. Most drivers don't care about this, but some do.
1384 static inline bool bvec_gap_to_prev(struct request_queue *q,
1385 struct bio_vec *bprv, unsigned int offset)
1387 if (!queue_virt_boundary(q))
1389 return __bvec_gap_to_prev(q, bprv, offset);
1392 static inline bool bio_will_gap(struct request_queue *q, struct bio *prev,
1395 if (bio_has_data(prev) && queue_virt_boundary(q)) {
1396 struct bio_vec pb, nb;
1398 bio_get_last_bvec(prev, &pb);
1399 bio_get_first_bvec(next, &nb);
1401 return __bvec_gap_to_prev(q, &pb, nb.bv_offset);
1407 static inline bool req_gap_back_merge(struct request *req, struct bio *bio)
1409 return bio_will_gap(req->q, req->biotail, bio);
1412 static inline bool req_gap_front_merge(struct request *req, struct bio *bio)
1414 return bio_will_gap(req->q, bio, req->bio);
1418 int kblockd_schedule_work(struct work_struct *work);
1419 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
1420 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1422 #ifdef CONFIG_BLK_CGROUP
1424 * This should not be using sched_clock(). A real patch is in progress
1425 * to fix this up, until that is in place we need to disable preemption
1426 * around sched_clock() in this function and set_io_start_time_ns().
1428 static inline void set_start_time_ns(struct request *req)
1431 req->start_time_ns = sched_clock();
1435 static inline void set_io_start_time_ns(struct request *req)
1438 req->io_start_time_ns = sched_clock();
1442 static inline uint64_t rq_start_time_ns(struct request *req)
1444 return req->start_time_ns;
1447 static inline uint64_t rq_io_start_time_ns(struct request *req)
1449 return req->io_start_time_ns;
1452 static inline void set_start_time_ns(struct request *req) {}
1453 static inline void set_io_start_time_ns(struct request *req) {}
1454 static inline uint64_t rq_start_time_ns(struct request *req)
1458 static inline uint64_t rq_io_start_time_ns(struct request *req)
1464 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1465 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1466 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1467 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1469 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1471 enum blk_integrity_flags {
1472 BLK_INTEGRITY_VERIFY = 1 << 0,
1473 BLK_INTEGRITY_GENERATE = 1 << 1,
1474 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2,
1475 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3,
1478 struct blk_integrity_iter {
1482 unsigned int data_size;
1483 unsigned short interval;
1484 const char *disk_name;
1487 typedef int (integrity_processing_fn) (struct blk_integrity_iter *);
1489 struct blk_integrity_profile {
1490 integrity_processing_fn *generate_fn;
1491 integrity_processing_fn *verify_fn;
1495 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *);
1496 extern void blk_integrity_unregister(struct gendisk *);
1497 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1498 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1499 struct scatterlist *);
1500 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1501 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1503 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1506 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1508 struct blk_integrity *bi = &disk->queue->integrity;
1517 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1519 return blk_get_integrity(bdev->bd_disk);
1522 static inline bool blk_integrity_rq(struct request *rq)
1524 return rq->cmd_flags & REQ_INTEGRITY;
1527 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1530 q->limits.max_integrity_segments = segs;
1533 static inline unsigned short
1534 queue_max_integrity_segments(struct request_queue *q)
1536 return q->limits.max_integrity_segments;
1539 static inline bool integrity_req_gap_back_merge(struct request *req,
1542 struct bio_integrity_payload *bip = bio_integrity(req->bio);
1543 struct bio_integrity_payload *bip_next = bio_integrity(next);
1545 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
1546 bip_next->bip_vec[0].bv_offset);
1549 static inline bool integrity_req_gap_front_merge(struct request *req,
1552 struct bio_integrity_payload *bip = bio_integrity(bio);
1553 struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
1555 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
1556 bip_next->bip_vec[0].bv_offset);
1559 #else /* CONFIG_BLK_DEV_INTEGRITY */
1562 struct block_device;
1564 struct blk_integrity;
1566 static inline int blk_integrity_rq(struct request *rq)
1570 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1575 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1577 struct scatterlist *s)
1581 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1585 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1589 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1593 static inline void blk_integrity_register(struct gendisk *d,
1594 struct blk_integrity *b)
1597 static inline void blk_integrity_unregister(struct gendisk *d)
1600 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1604 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1608 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1614 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1621 static inline bool integrity_req_gap_back_merge(struct request *req,
1626 static inline bool integrity_req_gap_front_merge(struct request *req,
1632 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1634 struct block_device_operations {
1635 int (*open) (struct block_device *, fmode_t);
1636 void (*release) (struct gendisk *, fmode_t);
1637 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
1638 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1639 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1640 long (*direct_access)(struct block_device *, sector_t, void __pmem **,
1641 unsigned long *pfn);
1642 unsigned int (*check_events) (struct gendisk *disk,
1643 unsigned int clearing);
1644 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1645 int (*media_changed) (struct gendisk *);
1646 void (*unlock_native_capacity) (struct gendisk *);
1647 int (*revalidate_disk) (struct gendisk *);
1648 int (*getgeo)(struct block_device *, struct hd_geometry *);
1649 /* this callback is with swap_lock and sometimes page table lock held */
1650 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1651 struct module *owner;
1652 const struct pr_ops *pr_ops;
1655 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1657 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1658 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1659 struct writeback_control *);
1660 extern long bdev_direct_access(struct block_device *, sector_t,
1661 void __pmem **addr, unsigned long *pfn, long size);
1664 * X-axis for IO latency histogram support.
1666 static const u_int64_t latency_x_axis_us[] = {
1692 #define BLK_IO_LAT_HIST_DISABLE 0
1693 #define BLK_IO_LAT_HIST_ENABLE 1
1694 #define BLK_IO_LAT_HIST_ZERO 2
1696 struct io_latency_state {
1697 u_int64_t latency_y_axis_read[ARRAY_SIZE(latency_x_axis_us) + 1];
1698 u_int64_t latency_reads_elems;
1699 u_int64_t latency_y_axis_write[ARRAY_SIZE(latency_x_axis_us) + 1];
1700 u_int64_t latency_writes_elems;
1704 blk_update_latency_hist(struct io_latency_state *s,
1710 for (i = 0; i < ARRAY_SIZE(latency_x_axis_us); i++) {
1711 if (delta_us < (u_int64_t)latency_x_axis_us[i]) {
1713 s->latency_y_axis_read[i]++;
1715 s->latency_y_axis_write[i]++;
1719 if (i == ARRAY_SIZE(latency_x_axis_us)) {
1720 /* Overflowed the histogram */
1722 s->latency_y_axis_read[i]++;
1724 s->latency_y_axis_write[i]++;
1727 s->latency_reads_elems++;
1729 s->latency_writes_elems++;
1732 void blk_zero_latency_hist(struct io_latency_state *s);
1733 ssize_t blk_latency_hist_show(struct io_latency_state *s, char *buf);
1735 #else /* CONFIG_BLOCK */
1737 struct block_device;
1740 * stubs for when the block layer is configured out
1742 #define buffer_heads_over_limit 0
1744 static inline long nr_blockdev_pages(void)
1752 static inline void blk_start_plug(struct blk_plug *plug)
1756 static inline void blk_finish_plug(struct blk_plug *plug)
1760 static inline void blk_flush_plug(struct task_struct *task)
1764 static inline void blk_schedule_flush_plug(struct task_struct *task)
1769 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1774 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1775 sector_t *error_sector)
1780 #endif /* CONFIG_BLOCK */