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.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>
26 #include <asm/scatterlist.h>
29 struct scsi_ioctl_command;
32 struct elevator_queue;
33 struct request_pm_state;
39 struct blk_flush_queue;
41 #define BLKDEV_MIN_RQ 4
42 #define BLKDEV_MAX_RQ 128 /* Default maximum */
45 * Maximum number of blkcg policies allowed to be registered concurrently.
46 * Defined here to simplify include dependency.
48 #define BLKCG_MAX_POLS 2
51 typedef void (rq_end_io_fn)(struct request *, int);
53 #define BLK_RL_SYNCFULL (1U << 0)
54 #define BLK_RL_ASYNCFULL (1U << 1)
57 struct request_queue *q; /* the queue this rl belongs to */
58 #ifdef CONFIG_BLK_CGROUP
59 struct blkcg_gq *blkg; /* blkg this request pool belongs to */
62 * count[], starved[], and wait[] are indexed by
63 * BLK_RW_SYNC/BLK_RW_ASYNC
68 wait_queue_head_t wait[2];
73 * request command types
75 enum rq_cmd_type_bits {
76 REQ_TYPE_FS = 1, /* fs request */
77 REQ_TYPE_BLOCK_PC, /* scsi command */
78 REQ_TYPE_SENSE, /* sense request */
79 REQ_TYPE_PM_SUSPEND, /* suspend request */
80 REQ_TYPE_PM_RESUME, /* resume request */
81 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
82 REQ_TYPE_SPECIAL, /* driver defined type */
84 * for ATA/ATAPI devices. this really doesn't belong here, ide should
85 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
86 * private REQ_LB opcodes to differentiate what type of request this is
88 REQ_TYPE_ATA_TASKFILE,
92 #define BLK_MAX_CDB 16
95 * Try to put the fields that are referenced together in the same cacheline.
97 * If you modify this structure, make sure to update blk_rq_init() and
98 * especially blk_mq_rq_ctx_init() to take care of the added fields.
101 struct list_head queuelist;
103 struct call_single_data csd;
104 unsigned long fifo_time;
107 struct request_queue *q;
108 struct blk_mq_ctx *mq_ctx;
111 enum rq_cmd_type_bits cmd_type;
112 unsigned long atomic_flags;
116 /* the following two fields are internal, NEVER access directly */
117 unsigned int __data_len; /* total data len */
118 sector_t __sector; /* sector cursor */
124 * The hash is used inside the scheduler, and killed once the
125 * request reaches the dispatch list. The ipi_list is only used
126 * to queue the request for softirq completion, which is long
127 * after the request has been unhashed (and even removed from
128 * the dispatch list).
131 struct hlist_node hash; /* merge hash */
132 struct list_head ipi_list;
136 * The rb_node is only used inside the io scheduler, requests
137 * are pruned when moved to the dispatch queue. So let the
138 * completion_data share space with the rb_node.
141 struct rb_node rb_node; /* sort/lookup */
142 void *completion_data;
146 * Three pointers are available for the IO schedulers, if they need
147 * more they have to dynamically allocate it. Flush requests are
148 * never put on the IO scheduler. So let the flush fields share
149 * space with the elevator data.
159 struct list_head list;
160 rq_end_io_fn *saved_end_io;
164 struct gendisk *rq_disk;
165 struct hd_struct *part;
166 unsigned long start_time;
167 #ifdef CONFIG_BLK_CGROUP
168 struct request_list *rl; /* rl this rq is alloced from */
169 unsigned long long start_time_ns;
170 unsigned long long io_start_time_ns; /* when passed to hardware */
172 /* Number of scatter-gather DMA addr+len pairs after
173 * physical address coalescing is performed.
175 unsigned short nr_phys_segments;
176 #if defined(CONFIG_BLK_DEV_INTEGRITY)
177 unsigned short nr_integrity_segments;
180 unsigned short ioprio;
182 void *special; /* opaque pointer available for LLD use */
188 * when request is used as a packet command carrier
190 unsigned char __cmd[BLK_MAX_CDB];
192 unsigned short cmd_len;
194 unsigned int extra_len; /* length of alignment and padding */
195 unsigned int sense_len;
196 unsigned int resid_len; /* residual count */
199 unsigned long deadline;
200 struct list_head timeout_list;
201 unsigned int timeout;
205 * completion callback.
207 rq_end_io_fn *end_io;
211 struct request *next_rq;
214 static inline unsigned short req_get_ioprio(struct request *req)
220 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
221 * requests. Some step values could eventually be made generic.
223 struct request_pm_state
225 /* PM state machine step value, currently driver specific */
227 /* requested PM state value (S1, S2, S3, S4, ...) */
229 void* data; /* for driver use */
232 #include <linux/elevator.h>
234 struct blk_queue_ctx;
236 typedef void (request_fn_proc) (struct request_queue *q);
237 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
238 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
239 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
242 struct bvec_merge_data {
243 struct block_device *bi_bdev;
248 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
250 typedef void (softirq_done_fn)(struct request *);
251 typedef int (dma_drain_needed_fn)(struct request *);
252 typedef int (lld_busy_fn) (struct request_queue *q);
253 typedef int (bsg_job_fn) (struct bsg_job *);
255 enum blk_eh_timer_return {
261 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
263 enum blk_queue_state {
268 struct blk_queue_tag {
269 struct request **tag_index; /* map of busy tags */
270 unsigned long *tag_map; /* bit map of free/busy tags */
271 int busy; /* current depth */
272 int max_depth; /* what we will send to device */
273 int real_max_depth; /* what the array can hold */
274 atomic_t refcnt; /* map can be shared */
275 int alloc_policy; /* tag allocation policy */
276 int next_tag; /* next tag */
278 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
279 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
281 #define BLK_SCSI_MAX_CMDS (256)
282 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
284 struct queue_limits {
285 unsigned long bounce_pfn;
286 unsigned long seg_boundary_mask;
288 unsigned int max_hw_sectors;
289 unsigned int chunk_sectors;
290 unsigned int max_sectors;
291 unsigned int max_segment_size;
292 unsigned int physical_block_size;
293 unsigned int alignment_offset;
296 unsigned int max_discard_sectors;
297 unsigned int max_write_same_sectors;
298 unsigned int discard_granularity;
299 unsigned int discard_alignment;
301 unsigned short logical_block_size;
302 unsigned short max_segments;
303 unsigned short max_integrity_segments;
305 unsigned char misaligned;
306 unsigned char discard_misaligned;
307 unsigned char cluster;
308 unsigned char discard_zeroes_data;
309 unsigned char raid_partial_stripes_expensive;
312 struct request_queue {
314 * Together with queue_head for cacheline sharing
316 struct list_head queue_head;
317 struct request *last_merge;
318 struct elevator_queue *elevator;
319 int nr_rqs[2]; /* # allocated [a]sync rqs */
320 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
323 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
324 * is used, root blkg allocates from @q->root_rl and all other
325 * blkgs from their own blkg->rl. Which one to use should be
326 * determined using bio_request_list().
328 struct request_list root_rl;
330 request_fn_proc *request_fn;
331 make_request_fn *make_request_fn;
332 prep_rq_fn *prep_rq_fn;
333 unprep_rq_fn *unprep_rq_fn;
334 merge_bvec_fn *merge_bvec_fn;
335 softirq_done_fn *softirq_done_fn;
336 rq_timed_out_fn *rq_timed_out_fn;
337 dma_drain_needed_fn *dma_drain_needed;
338 lld_busy_fn *lld_busy_fn;
340 struct blk_mq_ops *mq_ops;
342 unsigned int *mq_map;
345 struct blk_mq_ctx __percpu *queue_ctx;
346 unsigned int nr_queues;
348 /* hw dispatch queues */
349 struct blk_mq_hw_ctx **queue_hw_ctx;
350 unsigned int nr_hw_queues;
353 * Dispatch queue sorting
356 struct request *boundary_rq;
359 * Delayed queue handling
361 struct delayed_work delay_work;
363 struct backing_dev_info backing_dev_info;
366 * The queue owner gets to use this for whatever they like.
367 * ll_rw_blk doesn't touch it.
372 * various queue flags, see QUEUE_* below
374 unsigned long queue_flags;
377 * ida allocated id for this queue. Used to index queues from
383 * queue needs bounce pages for pages above this limit
388 * protects queue structures from reentrancy. ->__queue_lock should
389 * _never_ be used directly, it is queue private. always use
392 spinlock_t __queue_lock;
393 spinlock_t *queue_lock;
403 struct kobject mq_kobj;
408 unsigned int nr_pending;
414 unsigned long nr_requests; /* Max # of requests */
415 unsigned int nr_congestion_on;
416 unsigned int nr_congestion_off;
417 unsigned int nr_batching;
419 unsigned int dma_drain_size;
420 void *dma_drain_buffer;
421 unsigned int dma_pad_mask;
422 unsigned int dma_alignment;
424 struct blk_queue_tag *queue_tags;
425 struct list_head tag_busy_list;
427 unsigned int nr_sorted;
428 unsigned int in_flight[2];
430 * Number of active block driver functions for which blk_drain_queue()
431 * must wait. Must be incremented around functions that unlock the
432 * queue_lock internally, e.g. scsi_request_fn().
434 unsigned int request_fn_active;
436 unsigned int rq_timeout;
437 struct timer_list timeout;
438 struct list_head timeout_list;
440 struct list_head icq_list;
441 #ifdef CONFIG_BLK_CGROUP
442 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
443 struct blkcg_gq *root_blkg;
444 struct list_head blkg_list;
447 struct queue_limits limits;
452 unsigned int sg_timeout;
453 unsigned int sg_reserved_size;
455 #ifdef CONFIG_BLK_DEV_IO_TRACE
456 struct blk_trace *blk_trace;
459 * for flush operations
461 unsigned int flush_flags;
462 unsigned int flush_not_queueable:1;
463 struct blk_flush_queue *fq;
465 struct list_head requeue_list;
466 spinlock_t requeue_lock;
467 struct work_struct requeue_work;
469 struct mutex sysfs_lock;
474 #if defined(CONFIG_BLK_DEV_BSG)
475 bsg_job_fn *bsg_job_fn;
477 struct bsg_class_device bsg_dev;
480 #ifdef CONFIG_BLK_DEV_THROTTLING
482 struct throtl_data *td;
484 struct rcu_head rcu_head;
485 wait_queue_head_t mq_freeze_wq;
486 struct percpu_ref mq_usage_counter;
487 struct list_head all_q_node;
489 struct blk_mq_tag_set *tag_set;
490 struct list_head tag_set_list;
493 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
494 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
495 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
496 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
497 #define QUEUE_FLAG_DYING 5 /* queue being torn down */
498 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
499 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
500 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
501 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
502 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
503 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
504 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
505 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
506 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
507 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
508 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
509 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
510 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
511 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
512 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
513 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
514 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
515 #define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */
517 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
518 (1 << QUEUE_FLAG_STACKABLE) | \
519 (1 << QUEUE_FLAG_SAME_COMP) | \
520 (1 << QUEUE_FLAG_ADD_RANDOM))
522 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
523 (1 << QUEUE_FLAG_STACKABLE) | \
524 (1 << QUEUE_FLAG_SAME_COMP))
526 static inline void queue_lockdep_assert_held(struct request_queue *q)
529 lockdep_assert_held(q->queue_lock);
532 static inline void queue_flag_set_unlocked(unsigned int flag,
533 struct request_queue *q)
535 __set_bit(flag, &q->queue_flags);
538 static inline int queue_flag_test_and_clear(unsigned int flag,
539 struct request_queue *q)
541 queue_lockdep_assert_held(q);
543 if (test_bit(flag, &q->queue_flags)) {
544 __clear_bit(flag, &q->queue_flags);
551 static inline int queue_flag_test_and_set(unsigned int flag,
552 struct request_queue *q)
554 queue_lockdep_assert_held(q);
556 if (!test_bit(flag, &q->queue_flags)) {
557 __set_bit(flag, &q->queue_flags);
564 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
566 queue_lockdep_assert_held(q);
567 __set_bit(flag, &q->queue_flags);
570 static inline void queue_flag_clear_unlocked(unsigned int flag,
571 struct request_queue *q)
573 __clear_bit(flag, &q->queue_flags);
576 static inline int queue_in_flight(struct request_queue *q)
578 return q->in_flight[0] + q->in_flight[1];
581 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
583 queue_lockdep_assert_held(q);
584 __clear_bit(flag, &q->queue_flags);
587 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
588 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
589 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
590 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
591 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
592 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
593 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
594 #define blk_queue_noxmerges(q) \
595 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
596 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
597 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
598 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
599 #define blk_queue_stackable(q) \
600 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
601 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
602 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
603 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
605 #define blk_noretry_request(rq) \
606 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
607 REQ_FAILFAST_DRIVER))
609 #define blk_account_rq(rq) \
610 (((rq)->cmd_flags & REQ_STARTED) && \
611 ((rq)->cmd_type == REQ_TYPE_FS))
613 #define blk_pm_request(rq) \
614 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
615 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
617 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
618 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
619 /* rq->queuelist of dequeued request must be list_empty() */
620 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
622 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
624 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
627 * Driver can handle struct request, if it either has an old style
628 * request_fn defined, or is blk-mq based.
630 static inline bool queue_is_rq_based(struct request_queue *q)
632 return q->request_fn || q->mq_ops;
635 static inline unsigned int blk_queue_cluster(struct request_queue *q)
637 return q->limits.cluster;
641 * We regard a request as sync, if either a read or a sync write
643 static inline bool rw_is_sync(unsigned int rw_flags)
645 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
648 static inline bool rq_is_sync(struct request *rq)
650 return rw_is_sync(rq->cmd_flags);
653 static inline bool blk_rl_full(struct request_list *rl, bool sync)
655 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
657 return rl->flags & flag;
660 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
662 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
667 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
669 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
674 static inline bool rq_mergeable(struct request *rq)
676 if (rq->cmd_type != REQ_TYPE_FS)
679 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
685 static inline bool blk_check_merge_flags(unsigned int flags1,
688 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
691 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
694 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
700 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
702 if (bio_data(a) == bio_data(b))
709 * q->prep_rq_fn return values
711 #define BLKPREP_OK 0 /* serve it */
712 #define BLKPREP_KILL 1 /* fatal error, kill */
713 #define BLKPREP_DEFER 2 /* leave on queue */
715 extern unsigned long blk_max_low_pfn, blk_max_pfn;
718 * standard bounce addresses:
720 * BLK_BOUNCE_HIGH : bounce all highmem pages
721 * BLK_BOUNCE_ANY : don't bounce anything
722 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
725 #if BITS_PER_LONG == 32
726 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
728 #define BLK_BOUNCE_HIGH -1ULL
730 #define BLK_BOUNCE_ANY (-1ULL)
731 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
734 * default timeout for SG_IO if none specified
736 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
737 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
740 extern int init_emergency_isa_pool(void);
741 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
743 static inline int init_emergency_isa_pool(void)
747 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
750 #endif /* CONFIG_MMU */
756 unsigned long offset;
761 struct req_iterator {
762 struct bvec_iter iter;
766 /* This should not be used directly - use rq_for_each_segment */
767 #define for_each_bio(_bio) \
768 for (; _bio; _bio = _bio->bi_next)
769 #define __rq_for_each_bio(_bio, rq) \
771 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
773 #define rq_for_each_segment(bvl, _rq, _iter) \
774 __rq_for_each_bio(_iter.bio, _rq) \
775 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
777 #define rq_iter_last(bvec, _iter) \
778 (_iter.bio->bi_next == NULL && \
779 bio_iter_last(bvec, _iter.iter))
781 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
782 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
784 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
785 extern void rq_flush_dcache_pages(struct request *rq);
787 static inline void rq_flush_dcache_pages(struct request *rq)
792 extern int blk_register_queue(struct gendisk *disk);
793 extern void blk_unregister_queue(struct gendisk *disk);
794 extern void generic_make_request(struct bio *bio);
795 extern void blk_rq_init(struct request_queue *q, struct request *rq);
796 extern void blk_put_request(struct request *);
797 extern void __blk_put_request(struct request_queue *, struct request *);
798 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
799 extern struct request *blk_make_request(struct request_queue *, struct bio *,
801 extern void blk_rq_set_block_pc(struct request *);
802 extern void blk_requeue_request(struct request_queue *, struct request *);
803 extern void blk_add_request_payload(struct request *rq, struct page *page,
805 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
806 extern int blk_lld_busy(struct request_queue *q);
807 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
808 struct bio_set *bs, gfp_t gfp_mask,
809 int (*bio_ctr)(struct bio *, struct bio *, void *),
811 extern void blk_rq_unprep_clone(struct request *rq);
812 extern int blk_insert_cloned_request(struct request_queue *q,
814 extern void blk_delay_queue(struct request_queue *, unsigned long);
815 extern void blk_recount_segments(struct request_queue *, struct bio *);
816 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
817 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
818 unsigned int, void __user *);
819 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
820 unsigned int, void __user *);
821 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
822 struct scsi_ioctl_command __user *);
824 extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
827 * A queue has just exitted congestion. Note this in the global counter of
828 * congested queues, and wake up anyone who was waiting for requests to be
831 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
833 clear_bdi_congested(&q->backing_dev_info, sync);
837 * A queue has just entered congestion. Flag that in the queue's VM-visible
838 * state flags and increment the global gounter of congested queues.
840 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
842 set_bdi_congested(&q->backing_dev_info, sync);
845 extern void blk_start_queue(struct request_queue *q);
846 extern void blk_stop_queue(struct request_queue *q);
847 extern void blk_sync_queue(struct request_queue *q);
848 extern void __blk_stop_queue(struct request_queue *q);
849 extern void __blk_run_queue(struct request_queue *q);
850 extern void blk_run_queue(struct request_queue *);
851 extern void blk_run_queue_async(struct request_queue *q);
852 extern int blk_rq_map_user(struct request_queue *, struct request *,
853 struct rq_map_data *, void __user *, unsigned long,
855 extern int blk_rq_unmap_user(struct bio *);
856 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
857 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
858 struct rq_map_data *, const struct iov_iter *,
860 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
861 struct request *, int);
862 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
863 struct request *, int, rq_end_io_fn *);
865 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
867 return bdev->bd_disk->queue; /* this is never NULL */
871 * blk_rq_pos() : the current sector
872 * blk_rq_bytes() : bytes left in the entire request
873 * blk_rq_cur_bytes() : bytes left in the current segment
874 * blk_rq_err_bytes() : bytes left till the next error boundary
875 * blk_rq_sectors() : sectors left in the entire request
876 * blk_rq_cur_sectors() : sectors left in the current segment
878 static inline sector_t blk_rq_pos(const struct request *rq)
883 static inline unsigned int blk_rq_bytes(const struct request *rq)
885 return rq->__data_len;
888 static inline int blk_rq_cur_bytes(const struct request *rq)
890 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
893 extern unsigned int blk_rq_err_bytes(const struct request *rq);
895 static inline unsigned int blk_rq_sectors(const struct request *rq)
897 return blk_rq_bytes(rq) >> 9;
900 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
902 return blk_rq_cur_bytes(rq) >> 9;
905 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
906 unsigned int cmd_flags)
908 if (unlikely(cmd_flags & REQ_DISCARD))
909 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
911 if (unlikely(cmd_flags & REQ_WRITE_SAME))
912 return q->limits.max_write_same_sectors;
914 return q->limits.max_sectors;
918 * Return maximum size of a request at given offset. Only valid for
919 * file system requests.
921 static inline unsigned int blk_max_size_offset(struct request_queue *q,
924 if (!q->limits.chunk_sectors)
925 return q->limits.max_sectors;
927 return q->limits.chunk_sectors -
928 (offset & (q->limits.chunk_sectors - 1));
931 static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
933 struct request_queue *q = rq->q;
935 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
936 return q->limits.max_hw_sectors;
938 if (!q->limits.chunk_sectors)
939 return blk_queue_get_max_sectors(q, rq->cmd_flags);
941 return min(blk_max_size_offset(q, blk_rq_pos(rq)),
942 blk_queue_get_max_sectors(q, rq->cmd_flags));
945 static inline unsigned int blk_rq_count_bios(struct request *rq)
947 unsigned int nr_bios = 0;
950 __rq_for_each_bio(bio, rq)
957 * Request issue related functions.
959 extern struct request *blk_peek_request(struct request_queue *q);
960 extern void blk_start_request(struct request *rq);
961 extern struct request *blk_fetch_request(struct request_queue *q);
964 * Request completion related functions.
966 * blk_update_request() completes given number of bytes and updates
967 * the request without completing it.
969 * blk_end_request() and friends. __blk_end_request() must be called
970 * with the request queue spinlock acquired.
972 * Several drivers define their own end_request and call
973 * blk_end_request() for parts of the original function.
974 * This prevents code duplication in drivers.
976 extern bool blk_update_request(struct request *rq, int error,
977 unsigned int nr_bytes);
978 extern void blk_finish_request(struct request *rq, int error);
979 extern bool blk_end_request(struct request *rq, int error,
980 unsigned int nr_bytes);
981 extern void blk_end_request_all(struct request *rq, int error);
982 extern bool blk_end_request_cur(struct request *rq, int error);
983 extern bool blk_end_request_err(struct request *rq, int error);
984 extern bool __blk_end_request(struct request *rq, int error,
985 unsigned int nr_bytes);
986 extern void __blk_end_request_all(struct request *rq, int error);
987 extern bool __blk_end_request_cur(struct request *rq, int error);
988 extern bool __blk_end_request_err(struct request *rq, int error);
990 extern void blk_complete_request(struct request *);
991 extern void __blk_complete_request(struct request *);
992 extern void blk_abort_request(struct request *);
993 extern void blk_unprep_request(struct request *);
996 * Access functions for manipulating queue properties
998 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
999 spinlock_t *lock, int node_id);
1000 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
1001 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
1002 request_fn_proc *, spinlock_t *);
1003 extern void blk_cleanup_queue(struct request_queue *);
1004 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1005 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1006 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
1007 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1008 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1009 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1010 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1011 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1012 unsigned int max_discard_sectors);
1013 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1014 unsigned int max_write_same_sectors);
1015 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
1016 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1017 extern void blk_queue_alignment_offset(struct request_queue *q,
1018 unsigned int alignment);
1019 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1020 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1021 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1022 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1023 extern void blk_set_default_limits(struct queue_limits *lim);
1024 extern void blk_set_stacking_limits(struct queue_limits *lim);
1025 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1027 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1029 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1031 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1032 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1033 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1034 extern int blk_queue_dma_drain(struct request_queue *q,
1035 dma_drain_needed_fn *dma_drain_needed,
1036 void *buf, unsigned int size);
1037 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1038 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1039 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1040 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
1041 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
1042 extern void blk_queue_dma_alignment(struct request_queue *, int);
1043 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1044 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1045 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1046 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1047 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
1048 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1049 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1051 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1052 extern void blk_dump_rq_flags(struct request *, char *);
1053 extern long nr_blockdev_pages(void);
1055 bool __must_check blk_get_queue(struct request_queue *);
1056 struct request_queue *blk_alloc_queue(gfp_t);
1057 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1058 extern void blk_put_queue(struct request_queue *);
1061 * block layer runtime pm functions
1064 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1065 extern int blk_pre_runtime_suspend(struct request_queue *q);
1066 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1067 extern void blk_pre_runtime_resume(struct request_queue *q);
1068 extern void blk_post_runtime_resume(struct request_queue *q, int err);
1070 static inline void blk_pm_runtime_init(struct request_queue *q,
1071 struct device *dev) {}
1072 static inline int blk_pre_runtime_suspend(struct request_queue *q)
1076 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1077 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1078 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1082 * blk_plug permits building a queue of related requests by holding the I/O
1083 * fragments for a short period. This allows merging of sequential requests
1084 * into single larger request. As the requests are moved from a per-task list to
1085 * the device's request_queue in a batch, this results in improved scalability
1086 * as the lock contention for request_queue lock is reduced.
1088 * It is ok not to disable preemption when adding the request to the plug list
1089 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1090 * the plug list when the task sleeps by itself. For details, please see
1091 * schedule() where blk_schedule_flush_plug() is called.
1094 struct list_head list; /* requests */
1095 struct list_head mq_list; /* blk-mq requests */
1096 struct list_head cb_list; /* md requires an unplug callback */
1098 #define BLK_MAX_REQUEST_COUNT 16
1101 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1102 struct blk_plug_cb {
1103 struct list_head list;
1104 blk_plug_cb_fn callback;
1107 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1108 void *data, int size);
1109 extern void blk_start_plug(struct blk_plug *);
1110 extern void blk_finish_plug(struct blk_plug *);
1111 extern void blk_flush_plug_list(struct blk_plug *, bool);
1113 static inline void blk_flush_plug(struct task_struct *tsk)
1115 struct blk_plug *plug = tsk->plug;
1118 blk_flush_plug_list(plug, false);
1121 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1123 struct blk_plug *plug = tsk->plug;
1126 blk_flush_plug_list(plug, true);
1129 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1131 struct blk_plug *plug = tsk->plug;
1134 (!list_empty(&plug->list) ||
1135 !list_empty(&plug->mq_list) ||
1136 !list_empty(&plug->cb_list));
1142 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1143 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1144 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1145 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
1146 extern void blk_queue_free_tags(struct request_queue *);
1147 extern int blk_queue_resize_tags(struct request_queue *, int);
1148 extern void blk_queue_invalidate_tags(struct request_queue *);
1149 extern struct blk_queue_tag *blk_init_tags(int, int);
1150 extern void blk_free_tags(struct blk_queue_tag *);
1152 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1155 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1157 return bqt->tag_index[tag];
1160 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1162 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1163 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1164 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1165 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1166 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1167 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1168 sector_t nr_sects, gfp_t gfp_mask, bool discard);
1169 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1170 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1172 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1173 nr_blocks << (sb->s_blocksize_bits - 9),
1176 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1177 sector_t nr_blocks, gfp_t gfp_mask)
1179 return blkdev_issue_zeroout(sb->s_bdev,
1180 block << (sb->s_blocksize_bits - 9),
1181 nr_blocks << (sb->s_blocksize_bits - 9),
1185 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1187 enum blk_default_limits {
1188 BLK_MAX_SEGMENTS = 128,
1189 BLK_SAFE_MAX_SECTORS = 255,
1190 BLK_MAX_SEGMENT_SIZE = 65536,
1191 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1194 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1196 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1198 return q->limits.bounce_pfn;
1201 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1203 return q->limits.seg_boundary_mask;
1206 static inline unsigned int queue_max_sectors(struct request_queue *q)
1208 return q->limits.max_sectors;
1211 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1213 return q->limits.max_hw_sectors;
1216 static inline unsigned short queue_max_segments(struct request_queue *q)
1218 return q->limits.max_segments;
1221 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1223 return q->limits.max_segment_size;
1226 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1230 if (q && q->limits.logical_block_size)
1231 retval = q->limits.logical_block_size;
1236 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1238 return queue_logical_block_size(bdev_get_queue(bdev));
1241 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1243 return q->limits.physical_block_size;
1246 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1248 return queue_physical_block_size(bdev_get_queue(bdev));
1251 static inline unsigned int queue_io_min(struct request_queue *q)
1253 return q->limits.io_min;
1256 static inline int bdev_io_min(struct block_device *bdev)
1258 return queue_io_min(bdev_get_queue(bdev));
1261 static inline unsigned int queue_io_opt(struct request_queue *q)
1263 return q->limits.io_opt;
1266 static inline int bdev_io_opt(struct block_device *bdev)
1268 return queue_io_opt(bdev_get_queue(bdev));
1271 static inline int queue_alignment_offset(struct request_queue *q)
1273 if (q->limits.misaligned)
1276 return q->limits.alignment_offset;
1279 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1281 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1282 unsigned int alignment = sector_div(sector, granularity >> 9) << 9;
1284 return (granularity + lim->alignment_offset - alignment) % granularity;
1287 static inline int bdev_alignment_offset(struct block_device *bdev)
1289 struct request_queue *q = bdev_get_queue(bdev);
1291 if (q->limits.misaligned)
1294 if (bdev != bdev->bd_contains)
1295 return bdev->bd_part->alignment_offset;
1297 return q->limits.alignment_offset;
1300 static inline int queue_discard_alignment(struct request_queue *q)
1302 if (q->limits.discard_misaligned)
1305 return q->limits.discard_alignment;
1308 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1310 unsigned int alignment, granularity, offset;
1312 if (!lim->max_discard_sectors)
1315 /* Why are these in bytes, not sectors? */
1316 alignment = lim->discard_alignment >> 9;
1317 granularity = lim->discard_granularity >> 9;
1321 /* Offset of the partition start in 'granularity' sectors */
1322 offset = sector_div(sector, granularity);
1324 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1325 offset = (granularity + alignment - offset) % granularity;
1327 /* Turn it back into bytes, gaah */
1331 static inline int bdev_discard_alignment(struct block_device *bdev)
1333 struct request_queue *q = bdev_get_queue(bdev);
1335 if (bdev != bdev->bd_contains)
1336 return bdev->bd_part->discard_alignment;
1338 return q->limits.discard_alignment;
1341 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1343 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1349 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1351 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1354 static inline unsigned int bdev_write_same(struct block_device *bdev)
1356 struct request_queue *q = bdev_get_queue(bdev);
1359 return q->limits.max_write_same_sectors;
1364 static inline int queue_dma_alignment(struct request_queue *q)
1366 return q ? q->dma_alignment : 511;
1369 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1372 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1373 return !(addr & alignment) && !(len & alignment);
1376 /* assumes size > 256 */
1377 static inline unsigned int blksize_bits(unsigned int size)
1379 unsigned int bits = 8;
1383 } while (size > 256);
1387 static inline unsigned int block_size(struct block_device *bdev)
1389 return bdev->bd_block_size;
1392 static inline bool queue_flush_queueable(struct request_queue *q)
1394 return !q->flush_not_queueable;
1397 typedef struct {struct page *v;} Sector;
1399 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1401 static inline void put_dev_sector(Sector p)
1403 page_cache_release(p.v);
1407 int kblockd_schedule_work(struct work_struct *work);
1408 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
1409 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1411 #ifdef CONFIG_BLK_CGROUP
1413 * This should not be using sched_clock(). A real patch is in progress
1414 * to fix this up, until that is in place we need to disable preemption
1415 * around sched_clock() in this function and set_io_start_time_ns().
1417 static inline void set_start_time_ns(struct request *req)
1420 req->start_time_ns = sched_clock();
1424 static inline void set_io_start_time_ns(struct request *req)
1427 req->io_start_time_ns = sched_clock();
1431 static inline uint64_t rq_start_time_ns(struct request *req)
1433 return req->start_time_ns;
1436 static inline uint64_t rq_io_start_time_ns(struct request *req)
1438 return req->io_start_time_ns;
1441 static inline void set_start_time_ns(struct request *req) {}
1442 static inline void set_io_start_time_ns(struct request *req) {}
1443 static inline uint64_t rq_start_time_ns(struct request *req)
1447 static inline uint64_t rq_io_start_time_ns(struct request *req)
1453 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1454 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1455 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1456 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1458 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1460 enum blk_integrity_flags {
1461 BLK_INTEGRITY_VERIFY = 1 << 0,
1462 BLK_INTEGRITY_GENERATE = 1 << 1,
1463 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2,
1464 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3,
1467 struct blk_integrity_iter {
1471 unsigned int data_size;
1472 unsigned short interval;
1473 const char *disk_name;
1476 typedef int (integrity_processing_fn) (struct blk_integrity_iter *);
1478 struct blk_integrity {
1479 integrity_processing_fn *generate_fn;
1480 integrity_processing_fn *verify_fn;
1482 unsigned short flags;
1483 unsigned short tuple_size;
1484 unsigned short interval;
1485 unsigned short tag_size;
1489 struct kobject kobj;
1492 extern bool blk_integrity_is_initialized(struct gendisk *);
1493 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1494 extern void blk_integrity_unregister(struct gendisk *);
1495 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1496 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1497 struct scatterlist *);
1498 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1499 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1501 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1505 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1507 return bdev->bd_disk->integrity;
1510 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1512 return disk->integrity;
1515 static inline bool blk_integrity_rq(struct request *rq)
1517 return rq->cmd_flags & REQ_INTEGRITY;
1520 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1523 q->limits.max_integrity_segments = segs;
1526 static inline unsigned short
1527 queue_max_integrity_segments(struct request_queue *q)
1529 return q->limits.max_integrity_segments;
1532 #else /* CONFIG_BLK_DEV_INTEGRITY */
1535 struct block_device;
1537 struct blk_integrity;
1539 static inline int blk_integrity_rq(struct request *rq)
1543 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1548 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1550 struct scatterlist *s)
1554 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1558 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1562 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1566 static inline int blk_integrity_register(struct gendisk *d,
1567 struct blk_integrity *b)
1571 static inline void blk_integrity_unregister(struct gendisk *d)
1574 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1578 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1582 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1588 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1594 static inline bool blk_integrity_is_initialized(struct gendisk *g)
1599 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1601 struct block_device_operations {
1602 int (*open) (struct block_device *, fmode_t);
1603 void (*release) (struct gendisk *, fmode_t);
1604 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
1605 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1606 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1607 long (*direct_access)(struct block_device *, sector_t,
1608 void **, unsigned long *pfn, long size);
1609 unsigned int (*check_events) (struct gendisk *disk,
1610 unsigned int clearing);
1611 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1612 int (*media_changed) (struct gendisk *);
1613 void (*unlock_native_capacity) (struct gendisk *);
1614 int (*revalidate_disk) (struct gendisk *);
1615 int (*getgeo)(struct block_device *, struct hd_geometry *);
1616 /* this callback is with swap_lock and sometimes page table lock held */
1617 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1618 struct module *owner;
1621 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1623 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1624 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1625 struct writeback_control *);
1626 extern long bdev_direct_access(struct block_device *, sector_t, void **addr,
1627 unsigned long *pfn, long size);
1628 #else /* CONFIG_BLOCK */
1630 struct block_device;
1633 * stubs for when the block layer is configured out
1635 #define buffer_heads_over_limit 0
1637 static inline long nr_blockdev_pages(void)
1645 static inline void blk_start_plug(struct blk_plug *plug)
1649 static inline void blk_finish_plug(struct blk_plug *plug)
1653 static inline void blk_flush_plug(struct task_struct *task)
1657 static inline void blk_schedule_flush_plug(struct task_struct *task)
1662 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1667 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1668 sector_t *error_sector)
1673 #endif /* CONFIG_BLOCK */