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;
39 #define BLKDEV_MIN_RQ 4
40 #define BLKDEV_MAX_RQ 128 /* Default maximum */
43 * Maximum number of blkcg policies allowed to be registered concurrently.
44 * Defined here to simplify include dependency.
46 #define BLKCG_MAX_POLS 2
49 typedef void (rq_end_io_fn)(struct request *, int);
51 #define BLK_RL_SYNCFULL (1U << 0)
52 #define BLK_RL_ASYNCFULL (1U << 1)
55 struct request_queue *q; /* the queue this rl belongs to */
56 #ifdef CONFIG_BLK_CGROUP
57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */
60 * count[], starved[], and wait[] are indexed by
61 * BLK_RW_SYNC/BLK_RW_ASYNC
66 wait_queue_head_t wait[2];
71 * request command types
73 enum rq_cmd_type_bits {
74 REQ_TYPE_FS = 1, /* fs request */
75 REQ_TYPE_BLOCK_PC, /* scsi command */
76 REQ_TYPE_DRV_PRIV, /* driver defined types from here */
79 #define BLK_MAX_CDB 16
82 * Try to put the fields that are referenced together in the same cacheline.
84 * If you modify this structure, make sure to update blk_rq_init() and
85 * especially blk_mq_rq_ctx_init() to take care of the added fields.
88 struct list_head queuelist;
90 struct call_single_data csd;
91 unsigned long fifo_time;
94 struct request_queue *q;
95 struct blk_mq_ctx *mq_ctx;
99 unsigned long atomic_flags;
103 /* the following two fields are internal, NEVER access directly */
104 unsigned int __data_len; /* total data len */
105 sector_t __sector; /* sector cursor */
111 * The hash is used inside the scheduler, and killed once the
112 * request reaches the dispatch list. The ipi_list is only used
113 * to queue the request for softirq completion, which is long
114 * after the request has been unhashed (and even removed from
115 * the dispatch list).
118 struct hlist_node hash; /* merge hash */
119 struct list_head ipi_list;
123 * The rb_node is only used inside the io scheduler, requests
124 * are pruned when moved to the dispatch queue. So let the
125 * completion_data share space with the rb_node.
128 struct rb_node rb_node; /* sort/lookup */
129 void *completion_data;
133 * Three pointers are available for the IO schedulers, if they need
134 * more they have to dynamically allocate it. Flush requests are
135 * never put on the IO scheduler. So let the flush fields share
136 * space with the elevator data.
146 struct list_head list;
147 rq_end_io_fn *saved_end_io;
151 struct gendisk *rq_disk;
152 struct hd_struct *part;
153 unsigned long start_time;
154 #ifdef CONFIG_BLK_CGROUP
155 struct request_list *rl; /* rl this rq is alloced from */
156 unsigned long long start_time_ns;
157 unsigned long long io_start_time_ns; /* when passed to hardware */
159 /* Number of scatter-gather DMA addr+len pairs after
160 * physical address coalescing is performed.
162 unsigned short nr_phys_segments;
163 #if defined(CONFIG_BLK_DEV_INTEGRITY)
164 unsigned short nr_integrity_segments;
167 unsigned short ioprio;
169 void *special; /* opaque pointer available for LLD use */
175 * when request is used as a packet command carrier
177 unsigned char __cmd[BLK_MAX_CDB];
179 unsigned short cmd_len;
181 unsigned int extra_len; /* length of alignment and padding */
182 unsigned int sense_len;
183 unsigned int resid_len; /* residual count */
186 unsigned long deadline;
187 struct list_head timeout_list;
188 unsigned int timeout;
192 * completion callback.
194 rq_end_io_fn *end_io;
198 struct request *next_rq;
201 static inline unsigned short req_get_ioprio(struct request *req)
206 #include <linux/elevator.h>
208 struct blk_queue_ctx;
210 typedef void (request_fn_proc) (struct request_queue *q);
211 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
212 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
213 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
216 struct bvec_merge_data {
217 struct block_device *bi_bdev;
222 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
224 typedef void (softirq_done_fn)(struct request *);
225 typedef int (dma_drain_needed_fn)(struct request *);
226 typedef int (lld_busy_fn) (struct request_queue *q);
227 typedef int (bsg_job_fn) (struct bsg_job *);
229 enum blk_eh_timer_return {
235 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
237 enum blk_queue_state {
242 struct blk_queue_tag {
243 struct request **tag_index; /* map of busy tags */
244 unsigned long *tag_map; /* bit map of free/busy tags */
245 int busy; /* current depth */
246 int max_depth; /* what we will send to device */
247 int real_max_depth; /* what the array can hold */
248 atomic_t refcnt; /* map can be shared */
249 int alloc_policy; /* tag allocation policy */
250 int next_tag; /* next tag */
252 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
253 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
255 #define BLK_SCSI_MAX_CMDS (256)
256 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
258 struct queue_limits {
259 unsigned long bounce_pfn;
260 unsigned long seg_boundary_mask;
262 unsigned int max_hw_sectors;
263 unsigned int chunk_sectors;
264 unsigned int max_sectors;
265 unsigned int max_segment_size;
266 unsigned int physical_block_size;
267 unsigned int alignment_offset;
270 unsigned int max_discard_sectors;
271 unsigned int max_write_same_sectors;
272 unsigned int discard_granularity;
273 unsigned int discard_alignment;
275 unsigned short logical_block_size;
276 unsigned short max_segments;
277 unsigned short max_integrity_segments;
279 unsigned char misaligned;
280 unsigned char discard_misaligned;
281 unsigned char cluster;
282 unsigned char discard_zeroes_data;
283 unsigned char raid_partial_stripes_expensive;
286 struct request_queue {
288 * Together with queue_head for cacheline sharing
290 struct list_head queue_head;
291 struct request *last_merge;
292 struct elevator_queue *elevator;
293 int nr_rqs[2]; /* # allocated [a]sync rqs */
294 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
297 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
298 * is used, root blkg allocates from @q->root_rl and all other
299 * blkgs from their own blkg->rl. Which one to use should be
300 * determined using bio_request_list().
302 struct request_list root_rl;
304 request_fn_proc *request_fn;
305 make_request_fn *make_request_fn;
306 prep_rq_fn *prep_rq_fn;
307 unprep_rq_fn *unprep_rq_fn;
308 merge_bvec_fn *merge_bvec_fn;
309 softirq_done_fn *softirq_done_fn;
310 rq_timed_out_fn *rq_timed_out_fn;
311 dma_drain_needed_fn *dma_drain_needed;
312 lld_busy_fn *lld_busy_fn;
314 struct blk_mq_ops *mq_ops;
316 unsigned int *mq_map;
319 struct blk_mq_ctx __percpu *queue_ctx;
320 unsigned int nr_queues;
322 /* hw dispatch queues */
323 struct blk_mq_hw_ctx **queue_hw_ctx;
324 unsigned int nr_hw_queues;
327 * Dispatch queue sorting
330 struct request *boundary_rq;
333 * Delayed queue handling
335 struct delayed_work delay_work;
337 struct backing_dev_info backing_dev_info;
340 * The queue owner gets to use this for whatever they like.
341 * ll_rw_blk doesn't touch it.
346 * various queue flags, see QUEUE_* below
348 unsigned long queue_flags;
351 * ida allocated id for this queue. Used to index queues from
357 * queue needs bounce pages for pages above this limit
362 * protects queue structures from reentrancy. ->__queue_lock should
363 * _never_ be used directly, it is queue private. always use
366 spinlock_t __queue_lock;
367 spinlock_t *queue_lock;
377 struct kobject mq_kobj;
382 unsigned int nr_pending;
388 unsigned long nr_requests; /* Max # of requests */
389 unsigned int nr_congestion_on;
390 unsigned int nr_congestion_off;
391 unsigned int nr_batching;
393 unsigned int dma_drain_size;
394 void *dma_drain_buffer;
395 unsigned int dma_pad_mask;
396 unsigned int dma_alignment;
398 struct blk_queue_tag *queue_tags;
399 struct list_head tag_busy_list;
401 unsigned int nr_sorted;
402 unsigned int in_flight[2];
404 * Number of active block driver functions for which blk_drain_queue()
405 * must wait. Must be incremented around functions that unlock the
406 * queue_lock internally, e.g. scsi_request_fn().
408 unsigned int request_fn_active;
410 unsigned int rq_timeout;
411 struct timer_list timeout;
412 struct list_head timeout_list;
414 struct list_head icq_list;
415 #ifdef CONFIG_BLK_CGROUP
416 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
417 struct blkcg_gq *root_blkg;
418 struct list_head blkg_list;
421 struct queue_limits limits;
426 unsigned int sg_timeout;
427 unsigned int sg_reserved_size;
429 #ifdef CONFIG_BLK_DEV_IO_TRACE
430 struct blk_trace *blk_trace;
433 * for flush operations
435 unsigned int flush_flags;
436 unsigned int flush_not_queueable:1;
437 struct blk_flush_queue *fq;
439 struct list_head requeue_list;
440 spinlock_t requeue_lock;
441 struct work_struct requeue_work;
443 struct mutex sysfs_lock;
446 atomic_t mq_freeze_depth;
448 #if defined(CONFIG_BLK_DEV_BSG)
449 bsg_job_fn *bsg_job_fn;
451 struct bsg_class_device bsg_dev;
454 #ifdef CONFIG_BLK_DEV_THROTTLING
456 struct throtl_data *td;
458 struct rcu_head rcu_head;
459 wait_queue_head_t mq_freeze_wq;
460 struct percpu_ref mq_usage_counter;
461 struct list_head all_q_node;
463 struct blk_mq_tag_set *tag_set;
464 struct list_head tag_set_list;
467 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
468 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
469 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
470 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
471 #define QUEUE_FLAG_DYING 5 /* queue being torn down */
472 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
473 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
474 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
475 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
476 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
477 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
478 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
479 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
480 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
481 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
482 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
483 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
484 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
485 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
486 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
487 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
488 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
489 #define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */
491 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
492 (1 << QUEUE_FLAG_STACKABLE) | \
493 (1 << QUEUE_FLAG_SAME_COMP) | \
494 (1 << QUEUE_FLAG_ADD_RANDOM))
496 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
497 (1 << QUEUE_FLAG_STACKABLE) | \
498 (1 << QUEUE_FLAG_SAME_COMP))
500 static inline void queue_lockdep_assert_held(struct request_queue *q)
503 lockdep_assert_held(q->queue_lock);
506 static inline void queue_flag_set_unlocked(unsigned int flag,
507 struct request_queue *q)
509 __set_bit(flag, &q->queue_flags);
512 static inline int queue_flag_test_and_clear(unsigned int flag,
513 struct request_queue *q)
515 queue_lockdep_assert_held(q);
517 if (test_bit(flag, &q->queue_flags)) {
518 __clear_bit(flag, &q->queue_flags);
525 static inline int queue_flag_test_and_set(unsigned int flag,
526 struct request_queue *q)
528 queue_lockdep_assert_held(q);
530 if (!test_bit(flag, &q->queue_flags)) {
531 __set_bit(flag, &q->queue_flags);
538 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
540 queue_lockdep_assert_held(q);
541 __set_bit(flag, &q->queue_flags);
544 static inline void queue_flag_clear_unlocked(unsigned int flag,
545 struct request_queue *q)
547 __clear_bit(flag, &q->queue_flags);
550 static inline int queue_in_flight(struct request_queue *q)
552 return q->in_flight[0] + q->in_flight[1];
555 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
557 queue_lockdep_assert_held(q);
558 __clear_bit(flag, &q->queue_flags);
561 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
562 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
563 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
564 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
565 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
566 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
567 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
568 #define blk_queue_noxmerges(q) \
569 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
570 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
571 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
572 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
573 #define blk_queue_stackable(q) \
574 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
575 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
576 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
577 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
579 #define blk_noretry_request(rq) \
580 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
581 REQ_FAILFAST_DRIVER))
583 #define blk_account_rq(rq) \
584 (((rq)->cmd_flags & REQ_STARTED) && \
585 ((rq)->cmd_type == REQ_TYPE_FS))
587 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
588 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
589 /* rq->queuelist of dequeued request must be list_empty() */
590 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
592 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
594 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
597 * Driver can handle struct request, if it either has an old style
598 * request_fn defined, or is blk-mq based.
600 static inline bool queue_is_rq_based(struct request_queue *q)
602 return q->request_fn || q->mq_ops;
605 static inline unsigned int blk_queue_cluster(struct request_queue *q)
607 return q->limits.cluster;
611 * We regard a request as sync, if either a read or a sync write
613 static inline bool rw_is_sync(unsigned int rw_flags)
615 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
618 static inline bool rq_is_sync(struct request *rq)
620 return rw_is_sync(rq->cmd_flags);
623 static inline bool blk_rl_full(struct request_list *rl, bool sync)
625 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
627 return rl->flags & flag;
630 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
632 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
637 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
639 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
644 static inline bool rq_mergeable(struct request *rq)
646 if (rq->cmd_type != REQ_TYPE_FS)
649 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
655 static inline bool blk_check_merge_flags(unsigned int flags1,
658 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
661 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
664 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
670 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
672 if (bio_data(a) == bio_data(b))
679 * q->prep_rq_fn return values
681 #define BLKPREP_OK 0 /* serve it */
682 #define BLKPREP_KILL 1 /* fatal error, kill */
683 #define BLKPREP_DEFER 2 /* leave on queue */
685 extern unsigned long blk_max_low_pfn, blk_max_pfn;
688 * standard bounce addresses:
690 * BLK_BOUNCE_HIGH : bounce all highmem pages
691 * BLK_BOUNCE_ANY : don't bounce anything
692 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
695 #if BITS_PER_LONG == 32
696 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
698 #define BLK_BOUNCE_HIGH -1ULL
700 #define BLK_BOUNCE_ANY (-1ULL)
701 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
704 * default timeout for SG_IO if none specified
706 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
707 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
710 extern int init_emergency_isa_pool(void);
711 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
713 static inline int init_emergency_isa_pool(void)
717 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
720 #endif /* CONFIG_MMU */
726 unsigned long offset;
731 struct req_iterator {
732 struct bvec_iter iter;
736 /* This should not be used directly - use rq_for_each_segment */
737 #define for_each_bio(_bio) \
738 for (; _bio; _bio = _bio->bi_next)
739 #define __rq_for_each_bio(_bio, rq) \
741 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
743 #define rq_for_each_segment(bvl, _rq, _iter) \
744 __rq_for_each_bio(_iter.bio, _rq) \
745 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
747 #define rq_iter_last(bvec, _iter) \
748 (_iter.bio->bi_next == NULL && \
749 bio_iter_last(bvec, _iter.iter))
751 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
752 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
754 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
755 extern void rq_flush_dcache_pages(struct request *rq);
757 static inline void rq_flush_dcache_pages(struct request *rq)
762 extern int blk_register_queue(struct gendisk *disk);
763 extern void blk_unregister_queue(struct gendisk *disk);
764 extern void generic_make_request(struct bio *bio);
765 extern void blk_rq_init(struct request_queue *q, struct request *rq);
766 extern void blk_put_request(struct request *);
767 extern void __blk_put_request(struct request_queue *, struct request *);
768 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
769 extern struct request *blk_make_request(struct request_queue *, struct bio *,
771 extern void blk_rq_set_block_pc(struct request *);
772 extern void blk_requeue_request(struct request_queue *, struct request *);
773 extern void blk_add_request_payload(struct request *rq, struct page *page,
775 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
776 extern int blk_lld_busy(struct request_queue *q);
777 extern void blk_rq_prep_clone(struct request *rq, struct request *rq_src);
778 extern int blk_insert_cloned_request(struct request_queue *q,
780 extern void blk_delay_queue(struct request_queue *, unsigned long);
781 extern void blk_recount_segments(struct request_queue *, struct bio *);
782 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
783 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
784 unsigned int, void __user *);
785 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
786 unsigned int, void __user *);
787 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
788 struct scsi_ioctl_command __user *);
790 extern void blk_start_queue(struct request_queue *q);
791 extern void blk_stop_queue(struct request_queue *q);
792 extern void blk_sync_queue(struct request_queue *q);
793 extern void __blk_stop_queue(struct request_queue *q);
794 extern void __blk_run_queue(struct request_queue *q);
795 extern void __blk_run_queue_uncond(struct request_queue *q);
796 extern void blk_run_queue(struct request_queue *);
797 extern void blk_run_queue_async(struct request_queue *q);
798 extern int blk_rq_map_user(struct request_queue *, struct request *,
799 struct rq_map_data *, void __user *, unsigned long,
801 extern int blk_rq_unmap_user(struct bio *);
802 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
803 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
804 struct rq_map_data *, const struct iov_iter *,
806 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
807 struct request *, int);
808 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
809 struct request *, int, rq_end_io_fn *);
811 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
813 return bdev->bd_disk->queue; /* this is never NULL */
817 * blk_rq_pos() : the current sector
818 * blk_rq_bytes() : bytes left in the entire request
819 * blk_rq_cur_bytes() : bytes left in the current segment
820 * blk_rq_err_bytes() : bytes left till the next error boundary
821 * blk_rq_sectors() : sectors left in the entire request
822 * blk_rq_cur_sectors() : sectors left in the current segment
824 static inline sector_t blk_rq_pos(const struct request *rq)
829 static inline unsigned int blk_rq_bytes(const struct request *rq)
831 return rq->__data_len;
834 static inline int blk_rq_cur_bytes(const struct request *rq)
836 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
839 extern unsigned int blk_rq_err_bytes(const struct request *rq);
841 static inline unsigned int blk_rq_sectors(const struct request *rq)
843 return blk_rq_bytes(rq) >> 9;
846 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
848 return blk_rq_cur_bytes(rq) >> 9;
851 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
852 unsigned int cmd_flags)
854 if (unlikely(cmd_flags & REQ_DISCARD))
855 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
857 if (unlikely(cmd_flags & REQ_WRITE_SAME))
858 return q->limits.max_write_same_sectors;
860 return q->limits.max_sectors;
864 * Return maximum size of a request at given offset. Only valid for
865 * file system requests.
867 static inline unsigned int blk_max_size_offset(struct request_queue *q,
870 if (!q->limits.chunk_sectors)
871 return q->limits.max_sectors;
873 return q->limits.chunk_sectors -
874 (offset & (q->limits.chunk_sectors - 1));
877 static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
879 struct request_queue *q = rq->q;
881 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
882 return q->limits.max_hw_sectors;
884 if (!q->limits.chunk_sectors || (rq->cmd_flags & REQ_DISCARD))
885 return blk_queue_get_max_sectors(q, rq->cmd_flags);
887 return min(blk_max_size_offset(q, blk_rq_pos(rq)),
888 blk_queue_get_max_sectors(q, rq->cmd_flags));
891 static inline unsigned int blk_rq_count_bios(struct request *rq)
893 unsigned int nr_bios = 0;
896 __rq_for_each_bio(bio, rq)
903 * Request issue related functions.
905 extern struct request *blk_peek_request(struct request_queue *q);
906 extern void blk_start_request(struct request *rq);
907 extern struct request *blk_fetch_request(struct request_queue *q);
910 * Request completion related functions.
912 * blk_update_request() completes given number of bytes and updates
913 * the request without completing it.
915 * blk_end_request() and friends. __blk_end_request() must be called
916 * with the request queue spinlock acquired.
918 * Several drivers define their own end_request and call
919 * blk_end_request() for parts of the original function.
920 * This prevents code duplication in drivers.
922 extern bool blk_update_request(struct request *rq, int error,
923 unsigned int nr_bytes);
924 extern void blk_finish_request(struct request *rq, int error);
925 extern bool blk_end_request(struct request *rq, int error,
926 unsigned int nr_bytes);
927 extern void blk_end_request_all(struct request *rq, int error);
928 extern bool blk_end_request_cur(struct request *rq, int error);
929 extern bool blk_end_request_err(struct request *rq, int error);
930 extern bool __blk_end_request(struct request *rq, int error,
931 unsigned int nr_bytes);
932 extern void __blk_end_request_all(struct request *rq, int error);
933 extern bool __blk_end_request_cur(struct request *rq, int error);
934 extern bool __blk_end_request_err(struct request *rq, int error);
936 extern void blk_complete_request(struct request *);
937 extern void __blk_complete_request(struct request *);
938 extern void blk_abort_request(struct request *);
939 extern void blk_unprep_request(struct request *);
942 * Access functions for manipulating queue properties
944 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
945 spinlock_t *lock, int node_id);
946 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
947 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
948 request_fn_proc *, spinlock_t *);
949 extern void blk_cleanup_queue(struct request_queue *);
950 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
951 extern void blk_queue_bounce_limit(struct request_queue *, u64);
952 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
953 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
954 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
955 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
956 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
957 extern void blk_queue_max_discard_sectors(struct request_queue *q,
958 unsigned int max_discard_sectors);
959 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
960 unsigned int max_write_same_sectors);
961 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
962 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
963 extern void blk_queue_alignment_offset(struct request_queue *q,
964 unsigned int alignment);
965 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
966 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
967 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
968 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
969 extern void blk_set_default_limits(struct queue_limits *lim);
970 extern void blk_set_stacking_limits(struct queue_limits *lim);
971 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
973 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
975 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
977 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
978 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
979 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
980 extern int blk_queue_dma_drain(struct request_queue *q,
981 dma_drain_needed_fn *dma_drain_needed,
982 void *buf, unsigned int size);
983 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
984 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
985 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
986 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
987 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
988 extern void blk_queue_dma_alignment(struct request_queue *, int);
989 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
990 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
991 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
992 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
993 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
994 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
995 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
997 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
998 extern void blk_dump_rq_flags(struct request *, char *);
999 extern long nr_blockdev_pages(void);
1001 bool __must_check blk_get_queue(struct request_queue *);
1002 struct request_queue *blk_alloc_queue(gfp_t);
1003 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1004 extern void blk_put_queue(struct request_queue *);
1005 extern void blk_set_queue_dying(struct request_queue *);
1008 * block layer runtime pm functions
1011 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1012 extern int blk_pre_runtime_suspend(struct request_queue *q);
1013 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1014 extern void blk_pre_runtime_resume(struct request_queue *q);
1015 extern void blk_post_runtime_resume(struct request_queue *q, int err);
1017 static inline void blk_pm_runtime_init(struct request_queue *q,
1018 struct device *dev) {}
1019 static inline int blk_pre_runtime_suspend(struct request_queue *q)
1023 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1024 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1025 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1029 * blk_plug permits building a queue of related requests by holding the I/O
1030 * fragments for a short period. This allows merging of sequential requests
1031 * into single larger request. As the requests are moved from a per-task list to
1032 * the device's request_queue in a batch, this results in improved scalability
1033 * as the lock contention for request_queue lock is reduced.
1035 * It is ok not to disable preemption when adding the request to the plug list
1036 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1037 * the plug list when the task sleeps by itself. For details, please see
1038 * schedule() where blk_schedule_flush_plug() is called.
1041 struct list_head list; /* requests */
1042 struct list_head mq_list; /* blk-mq requests */
1043 struct list_head cb_list; /* md requires an unplug callback */
1045 #define BLK_MAX_REQUEST_COUNT 16
1048 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1049 struct blk_plug_cb {
1050 struct list_head list;
1051 blk_plug_cb_fn callback;
1054 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1055 void *data, int size);
1056 extern void blk_start_plug(struct blk_plug *);
1057 extern void blk_finish_plug(struct blk_plug *);
1058 extern void blk_flush_plug_list(struct blk_plug *, bool);
1060 static inline void blk_flush_plug(struct task_struct *tsk)
1062 struct blk_plug *plug = tsk->plug;
1065 blk_flush_plug_list(plug, false);
1068 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1070 struct blk_plug *plug = tsk->plug;
1073 blk_flush_plug_list(plug, true);
1076 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1078 struct blk_plug *plug = tsk->plug;
1081 (!list_empty(&plug->list) ||
1082 !list_empty(&plug->mq_list) ||
1083 !list_empty(&plug->cb_list));
1089 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1090 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1091 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1092 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
1093 extern void blk_queue_free_tags(struct request_queue *);
1094 extern int blk_queue_resize_tags(struct request_queue *, int);
1095 extern void blk_queue_invalidate_tags(struct request_queue *);
1096 extern struct blk_queue_tag *blk_init_tags(int, int);
1097 extern void blk_free_tags(struct blk_queue_tag *);
1099 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1102 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1104 return bqt->tag_index[tag];
1107 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1109 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1110 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1111 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1112 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1113 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1114 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1115 sector_t nr_sects, gfp_t gfp_mask, bool discard);
1116 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1117 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1119 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1120 nr_blocks << (sb->s_blocksize_bits - 9),
1123 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1124 sector_t nr_blocks, gfp_t gfp_mask)
1126 return blkdev_issue_zeroout(sb->s_bdev,
1127 block << (sb->s_blocksize_bits - 9),
1128 nr_blocks << (sb->s_blocksize_bits - 9),
1132 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1134 enum blk_default_limits {
1135 BLK_MAX_SEGMENTS = 128,
1136 BLK_SAFE_MAX_SECTORS = 255,
1137 BLK_MAX_SEGMENT_SIZE = 65536,
1138 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1141 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1143 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1145 return q->limits.bounce_pfn;
1148 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1150 return q->limits.seg_boundary_mask;
1153 static inline unsigned int queue_max_sectors(struct request_queue *q)
1155 return q->limits.max_sectors;
1158 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1160 return q->limits.max_hw_sectors;
1163 static inline unsigned short queue_max_segments(struct request_queue *q)
1165 return q->limits.max_segments;
1168 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1170 return q->limits.max_segment_size;
1173 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1177 if (q && q->limits.logical_block_size)
1178 retval = q->limits.logical_block_size;
1183 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1185 return queue_logical_block_size(bdev_get_queue(bdev));
1188 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1190 return q->limits.physical_block_size;
1193 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1195 return queue_physical_block_size(bdev_get_queue(bdev));
1198 static inline unsigned int queue_io_min(struct request_queue *q)
1200 return q->limits.io_min;
1203 static inline int bdev_io_min(struct block_device *bdev)
1205 return queue_io_min(bdev_get_queue(bdev));
1208 static inline unsigned int queue_io_opt(struct request_queue *q)
1210 return q->limits.io_opt;
1213 static inline int bdev_io_opt(struct block_device *bdev)
1215 return queue_io_opt(bdev_get_queue(bdev));
1218 static inline int queue_alignment_offset(struct request_queue *q)
1220 if (q->limits.misaligned)
1223 return q->limits.alignment_offset;
1226 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1228 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1229 unsigned int alignment = sector_div(sector, granularity >> 9) << 9;
1231 return (granularity + lim->alignment_offset - alignment) % granularity;
1234 static inline int bdev_alignment_offset(struct block_device *bdev)
1236 struct request_queue *q = bdev_get_queue(bdev);
1238 if (q->limits.misaligned)
1241 if (bdev != bdev->bd_contains)
1242 return bdev->bd_part->alignment_offset;
1244 return q->limits.alignment_offset;
1247 static inline int queue_discard_alignment(struct request_queue *q)
1249 if (q->limits.discard_misaligned)
1252 return q->limits.discard_alignment;
1255 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1257 unsigned int alignment, granularity, offset;
1259 if (!lim->max_discard_sectors)
1262 /* Why are these in bytes, not sectors? */
1263 alignment = lim->discard_alignment >> 9;
1264 granularity = lim->discard_granularity >> 9;
1268 /* Offset of the partition start in 'granularity' sectors */
1269 offset = sector_div(sector, granularity);
1271 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1272 offset = (granularity + alignment - offset) % granularity;
1274 /* Turn it back into bytes, gaah */
1278 static inline int bdev_discard_alignment(struct block_device *bdev)
1280 struct request_queue *q = bdev_get_queue(bdev);
1282 if (bdev != bdev->bd_contains)
1283 return bdev->bd_part->discard_alignment;
1285 return q->limits.discard_alignment;
1288 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1290 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1296 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1298 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1301 static inline unsigned int bdev_write_same(struct block_device *bdev)
1303 struct request_queue *q = bdev_get_queue(bdev);
1306 return q->limits.max_write_same_sectors;
1311 static inline int queue_dma_alignment(struct request_queue *q)
1313 return q ? q->dma_alignment : 511;
1316 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1319 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1320 return !(addr & alignment) && !(len & alignment);
1323 /* assumes size > 256 */
1324 static inline unsigned int blksize_bits(unsigned int size)
1326 unsigned int bits = 8;
1330 } while (size > 256);
1334 static inline unsigned int block_size(struct block_device *bdev)
1336 return bdev->bd_block_size;
1339 static inline bool queue_flush_queueable(struct request_queue *q)
1341 return !q->flush_not_queueable;
1344 typedef struct {struct page *v;} Sector;
1346 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1348 static inline void put_dev_sector(Sector p)
1350 page_cache_release(p.v);
1354 int kblockd_schedule_work(struct work_struct *work);
1355 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
1356 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1358 #ifdef CONFIG_BLK_CGROUP
1360 * This should not be using sched_clock(). A real patch is in progress
1361 * to fix this up, until that is in place we need to disable preemption
1362 * around sched_clock() in this function and set_io_start_time_ns().
1364 static inline void set_start_time_ns(struct request *req)
1367 req->start_time_ns = sched_clock();
1371 static inline void set_io_start_time_ns(struct request *req)
1374 req->io_start_time_ns = sched_clock();
1378 static inline uint64_t rq_start_time_ns(struct request *req)
1380 return req->start_time_ns;
1383 static inline uint64_t rq_io_start_time_ns(struct request *req)
1385 return req->io_start_time_ns;
1388 static inline void set_start_time_ns(struct request *req) {}
1389 static inline void set_io_start_time_ns(struct request *req) {}
1390 static inline uint64_t rq_start_time_ns(struct request *req)
1394 static inline uint64_t rq_io_start_time_ns(struct request *req)
1400 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1401 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1402 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1403 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1405 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1407 enum blk_integrity_flags {
1408 BLK_INTEGRITY_VERIFY = 1 << 0,
1409 BLK_INTEGRITY_GENERATE = 1 << 1,
1410 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2,
1411 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3,
1414 struct blk_integrity_iter {
1418 unsigned int data_size;
1419 unsigned short interval;
1420 const char *disk_name;
1423 typedef int (integrity_processing_fn) (struct blk_integrity_iter *);
1425 struct blk_integrity {
1426 integrity_processing_fn *generate_fn;
1427 integrity_processing_fn *verify_fn;
1429 unsigned short flags;
1430 unsigned short tuple_size;
1431 unsigned short interval;
1432 unsigned short tag_size;
1436 struct kobject kobj;
1439 extern bool blk_integrity_is_initialized(struct gendisk *);
1440 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1441 extern void blk_integrity_unregister(struct gendisk *);
1442 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1443 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1444 struct scatterlist *);
1445 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1446 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1448 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1452 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1454 return bdev->bd_disk->integrity;
1457 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1459 return disk->integrity;
1462 static inline bool blk_integrity_rq(struct request *rq)
1464 return rq->cmd_flags & REQ_INTEGRITY;
1467 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1470 q->limits.max_integrity_segments = segs;
1473 static inline unsigned short
1474 queue_max_integrity_segments(struct request_queue *q)
1476 return q->limits.max_integrity_segments;
1479 #else /* CONFIG_BLK_DEV_INTEGRITY */
1482 struct block_device;
1484 struct blk_integrity;
1486 static inline int blk_integrity_rq(struct request *rq)
1490 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1495 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1497 struct scatterlist *s)
1501 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1505 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1509 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1513 static inline int blk_integrity_register(struct gendisk *d,
1514 struct blk_integrity *b)
1518 static inline void blk_integrity_unregister(struct gendisk *d)
1521 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1525 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1529 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1535 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1541 static inline bool blk_integrity_is_initialized(struct gendisk *g)
1546 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1548 struct block_device_operations {
1549 int (*open) (struct block_device *, fmode_t);
1550 void (*release) (struct gendisk *, fmode_t);
1551 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
1552 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1553 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1554 long (*direct_access)(struct block_device *, sector_t,
1555 void **, unsigned long *pfn, long size);
1556 unsigned int (*check_events) (struct gendisk *disk,
1557 unsigned int clearing);
1558 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1559 int (*media_changed) (struct gendisk *);
1560 void (*unlock_native_capacity) (struct gendisk *);
1561 int (*revalidate_disk) (struct gendisk *);
1562 int (*getgeo)(struct block_device *, struct hd_geometry *);
1563 /* this callback is with swap_lock and sometimes page table lock held */
1564 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1565 struct module *owner;
1568 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1570 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1571 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1572 struct writeback_control *);
1573 extern long bdev_direct_access(struct block_device *, sector_t, void **addr,
1574 unsigned long *pfn, long size);
1575 #else /* CONFIG_BLOCK */
1577 struct block_device;
1580 * stubs for when the block layer is configured out
1582 #define buffer_heads_over_limit 0
1584 static inline long nr_blockdev_pages(void)
1592 static inline void blk_start_plug(struct blk_plug *plug)
1596 static inline void blk_finish_plug(struct blk_plug *plug)
1600 static inline void blk_flush_plug(struct task_struct *task)
1604 static inline void blk_schedule_flush_plug(struct task_struct *task)
1609 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1614 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1615 sector_t *error_sector)
1620 #endif /* CONFIG_BLOCK */