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 struct work_struct work;
105 unsigned long fifo_time;
108 struct request_queue *q;
109 struct blk_mq_ctx *mq_ctx;
112 enum rq_cmd_type_bits cmd_type;
113 unsigned long atomic_flags;
117 /* the following two fields are internal, NEVER access directly */
118 unsigned int __data_len; /* total data len */
119 sector_t __sector; /* sector cursor */
125 * The hash is used inside the scheduler, and killed once the
126 * request reaches the dispatch list. The ipi_list is only used
127 * to queue the request for softirq completion, which is long
128 * after the request has been unhashed (and even removed from
129 * the dispatch list).
132 struct hlist_node hash; /* merge hash */
133 struct list_head ipi_list;
137 * The rb_node is only used inside the io scheduler, requests
138 * are pruned when moved to the dispatch queue. So let the
139 * completion_data share space with the rb_node.
142 struct rb_node rb_node; /* sort/lookup */
143 void *completion_data;
147 * Three pointers are available for the IO schedulers, if they need
148 * more they have to dynamically allocate it. Flush requests are
149 * never put on the IO scheduler. So let the flush fields share
150 * space with the elevator data.
160 struct list_head list;
161 rq_end_io_fn *saved_end_io;
165 struct gendisk *rq_disk;
166 struct hd_struct *part;
167 unsigned long start_time;
168 #ifdef CONFIG_BLK_CGROUP
169 struct request_list *rl; /* rl this rq is alloced from */
170 unsigned long long start_time_ns;
171 unsigned long long io_start_time_ns; /* when passed to hardware */
173 /* Number of scatter-gather DMA addr+len pairs after
174 * physical address coalescing is performed.
176 unsigned short nr_phys_segments;
177 #if defined(CONFIG_BLK_DEV_INTEGRITY)
178 unsigned short nr_integrity_segments;
181 unsigned short ioprio;
183 void *special; /* opaque pointer available for LLD use */
189 * when request is used as a packet command carrier
191 unsigned char __cmd[BLK_MAX_CDB];
193 unsigned short cmd_len;
195 unsigned int extra_len; /* length of alignment and padding */
196 unsigned int sense_len;
197 unsigned int resid_len; /* residual count */
200 unsigned long deadline;
201 struct list_head timeout_list;
202 unsigned int timeout;
206 * completion callback.
208 rq_end_io_fn *end_io;
212 struct request *next_rq;
215 static inline unsigned short req_get_ioprio(struct request *req)
221 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
222 * requests. Some step values could eventually be made generic.
224 struct request_pm_state
226 /* PM state machine step value, currently driver specific */
228 /* requested PM state value (S1, S2, S3, S4, ...) */
230 void* data; /* for driver use */
233 #include <linux/elevator.h>
235 struct blk_queue_ctx;
237 typedef void (request_fn_proc) (struct request_queue *q);
238 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
239 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
240 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
243 struct bvec_merge_data {
244 struct block_device *bi_bdev;
249 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
251 typedef void (softirq_done_fn)(struct request *);
252 typedef int (dma_drain_needed_fn)(struct request *);
253 typedef int (lld_busy_fn) (struct request_queue *q);
254 typedef int (bsg_job_fn) (struct bsg_job *);
256 enum blk_eh_timer_return {
262 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
264 enum blk_queue_state {
269 struct blk_queue_tag {
270 struct request **tag_index; /* map of busy tags */
271 unsigned long *tag_map; /* bit map of free/busy tags */
272 int busy; /* current depth */
273 int max_depth; /* what we will send to device */
274 int real_max_depth; /* what the array can hold */
275 atomic_t refcnt; /* map can be shared */
276 int alloc_policy; /* tag allocation policy */
277 int next_tag; /* next tag */
279 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
280 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
282 #define BLK_SCSI_MAX_CMDS (256)
283 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
285 struct queue_limits {
286 unsigned long bounce_pfn;
287 unsigned long seg_boundary_mask;
289 unsigned int max_hw_sectors;
290 unsigned int chunk_sectors;
291 unsigned int max_sectors;
292 unsigned int max_segment_size;
293 unsigned int physical_block_size;
294 unsigned int alignment_offset;
297 unsigned int max_discard_sectors;
298 unsigned int max_write_same_sectors;
299 unsigned int discard_granularity;
300 unsigned int discard_alignment;
302 unsigned short logical_block_size;
303 unsigned short max_segments;
304 unsigned short max_integrity_segments;
306 unsigned char misaligned;
307 unsigned char discard_misaligned;
308 unsigned char cluster;
309 unsigned char discard_zeroes_data;
310 unsigned char raid_partial_stripes_expensive;
313 struct request_queue {
315 * Together with queue_head for cacheline sharing
317 struct list_head queue_head;
318 struct request *last_merge;
319 struct elevator_queue *elevator;
320 int nr_rqs[2]; /* # allocated [a]sync rqs */
321 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
324 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
325 * is used, root blkg allocates from @q->root_rl and all other
326 * blkgs from their own blkg->rl. Which one to use should be
327 * determined using bio_request_list().
329 struct request_list root_rl;
331 request_fn_proc *request_fn;
332 make_request_fn *make_request_fn;
333 prep_rq_fn *prep_rq_fn;
334 unprep_rq_fn *unprep_rq_fn;
335 merge_bvec_fn *merge_bvec_fn;
336 softirq_done_fn *softirq_done_fn;
337 rq_timed_out_fn *rq_timed_out_fn;
338 dma_drain_needed_fn *dma_drain_needed;
339 lld_busy_fn *lld_busy_fn;
341 struct blk_mq_ops *mq_ops;
343 unsigned int *mq_map;
346 struct blk_mq_ctx __percpu *queue_ctx;
347 unsigned int nr_queues;
349 /* hw dispatch queues */
350 struct blk_mq_hw_ctx **queue_hw_ctx;
351 unsigned int nr_hw_queues;
354 * Dispatch queue sorting
357 struct request *boundary_rq;
360 * Delayed queue handling
362 struct delayed_work delay_work;
364 struct backing_dev_info backing_dev_info;
367 * The queue owner gets to use this for whatever they like.
368 * ll_rw_blk doesn't touch it.
373 * various queue flags, see QUEUE_* below
375 unsigned long queue_flags;
378 * ida allocated id for this queue. Used to index queues from
384 * queue needs bounce pages for pages above this limit
389 * protects queue structures from reentrancy. ->__queue_lock should
390 * _never_ be used directly, it is queue private. always use
393 spinlock_t __queue_lock;
394 spinlock_t *queue_lock;
404 struct kobject mq_kobj;
409 unsigned int nr_pending;
415 unsigned long nr_requests; /* Max # of requests */
416 unsigned int nr_congestion_on;
417 unsigned int nr_congestion_off;
418 unsigned int nr_batching;
420 unsigned int dma_drain_size;
421 void *dma_drain_buffer;
422 unsigned int dma_pad_mask;
423 unsigned int dma_alignment;
425 struct blk_queue_tag *queue_tags;
426 struct list_head tag_busy_list;
428 unsigned int nr_sorted;
429 unsigned int in_flight[2];
431 * Number of active block driver functions for which blk_drain_queue()
432 * must wait. Must be incremented around functions that unlock the
433 * queue_lock internally, e.g. scsi_request_fn().
435 unsigned int request_fn_active;
437 unsigned int rq_timeout;
438 struct timer_list timeout;
439 struct list_head timeout_list;
441 struct list_head icq_list;
442 #ifdef CONFIG_BLK_CGROUP
443 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
444 struct blkcg_gq *root_blkg;
445 struct list_head blkg_list;
448 struct queue_limits limits;
453 unsigned int sg_timeout;
454 unsigned int sg_reserved_size;
456 #ifdef CONFIG_BLK_DEV_IO_TRACE
457 struct blk_trace *blk_trace;
460 * for flush operations
462 unsigned int flush_flags;
463 unsigned int flush_not_queueable:1;
464 struct blk_flush_queue *fq;
466 struct list_head requeue_list;
467 spinlock_t requeue_lock;
468 struct work_struct requeue_work;
470 struct mutex sysfs_lock;
475 #if defined(CONFIG_BLK_DEV_BSG)
476 bsg_job_fn *bsg_job_fn;
478 struct bsg_class_device bsg_dev;
481 #ifdef CONFIG_BLK_DEV_THROTTLING
483 struct throtl_data *td;
485 struct rcu_head rcu_head;
486 struct swait_head mq_freeze_wq;
487 struct percpu_ref mq_usage_counter;
488 struct list_head all_q_node;
490 struct blk_mq_tag_set *tag_set;
491 struct list_head tag_set_list;
494 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
495 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
496 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
497 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
498 #define QUEUE_FLAG_DYING 5 /* queue being torn down */
499 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
500 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
501 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
502 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
503 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
504 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
505 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
506 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
507 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
508 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
509 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
510 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
511 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
512 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
513 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
514 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
515 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
516 #define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */
518 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
519 (1 << QUEUE_FLAG_STACKABLE) | \
520 (1 << QUEUE_FLAG_SAME_COMP) | \
521 (1 << QUEUE_FLAG_ADD_RANDOM))
523 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
524 (1 << QUEUE_FLAG_STACKABLE) | \
525 (1 << QUEUE_FLAG_SAME_COMP))
527 static inline void queue_lockdep_assert_held(struct request_queue *q)
530 lockdep_assert_held(q->queue_lock);
533 static inline void queue_flag_set_unlocked(unsigned int flag,
534 struct request_queue *q)
536 __set_bit(flag, &q->queue_flags);
539 static inline int queue_flag_test_and_clear(unsigned int flag,
540 struct request_queue *q)
542 queue_lockdep_assert_held(q);
544 if (test_bit(flag, &q->queue_flags)) {
545 __clear_bit(flag, &q->queue_flags);
552 static inline int queue_flag_test_and_set(unsigned int flag,
553 struct request_queue *q)
555 queue_lockdep_assert_held(q);
557 if (!test_bit(flag, &q->queue_flags)) {
558 __set_bit(flag, &q->queue_flags);
565 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
567 queue_lockdep_assert_held(q);
568 __set_bit(flag, &q->queue_flags);
571 static inline void queue_flag_clear_unlocked(unsigned int flag,
572 struct request_queue *q)
574 __clear_bit(flag, &q->queue_flags);
577 static inline int queue_in_flight(struct request_queue *q)
579 return q->in_flight[0] + q->in_flight[1];
582 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
584 queue_lockdep_assert_held(q);
585 __clear_bit(flag, &q->queue_flags);
588 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
589 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
590 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
591 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
592 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
593 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
594 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
595 #define blk_queue_noxmerges(q) \
596 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
597 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
598 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
599 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
600 #define blk_queue_stackable(q) \
601 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
602 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
603 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
604 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
606 #define blk_noretry_request(rq) \
607 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
608 REQ_FAILFAST_DRIVER))
610 #define blk_account_rq(rq) \
611 (((rq)->cmd_flags & REQ_STARTED) && \
612 ((rq)->cmd_type == REQ_TYPE_FS))
614 #define blk_pm_request(rq) \
615 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
616 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
618 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
619 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
620 /* rq->queuelist of dequeued request must be list_empty() */
621 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
623 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
625 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
628 * Driver can handle struct request, if it either has an old style
629 * request_fn defined, or is blk-mq based.
631 static inline bool queue_is_rq_based(struct request_queue *q)
633 return q->request_fn || q->mq_ops;
636 static inline unsigned int blk_queue_cluster(struct request_queue *q)
638 return q->limits.cluster;
642 * We regard a request as sync, if either a read or a sync write
644 static inline bool rw_is_sync(unsigned int rw_flags)
646 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
649 static inline bool rq_is_sync(struct request *rq)
651 return rw_is_sync(rq->cmd_flags);
654 static inline bool blk_rl_full(struct request_list *rl, bool sync)
656 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
658 return rl->flags & flag;
661 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
663 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
668 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
670 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
675 static inline bool rq_mergeable(struct request *rq)
677 if (rq->cmd_type != REQ_TYPE_FS)
680 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
686 static inline bool blk_check_merge_flags(unsigned int flags1,
689 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
692 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
695 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
701 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
703 if (bio_data(a) == bio_data(b))
710 * q->prep_rq_fn return values
712 #define BLKPREP_OK 0 /* serve it */
713 #define BLKPREP_KILL 1 /* fatal error, kill */
714 #define BLKPREP_DEFER 2 /* leave on queue */
716 extern unsigned long blk_max_low_pfn, blk_max_pfn;
719 * standard bounce addresses:
721 * BLK_BOUNCE_HIGH : bounce all highmem pages
722 * BLK_BOUNCE_ANY : don't bounce anything
723 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
726 #if BITS_PER_LONG == 32
727 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
729 #define BLK_BOUNCE_HIGH -1ULL
731 #define BLK_BOUNCE_ANY (-1ULL)
732 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
735 * default timeout for SG_IO if none specified
737 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
738 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
741 extern int init_emergency_isa_pool(void);
742 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
744 static inline int init_emergency_isa_pool(void)
748 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
751 #endif /* CONFIG_MMU */
757 unsigned long offset;
762 struct req_iterator {
763 struct bvec_iter iter;
767 /* This should not be used directly - use rq_for_each_segment */
768 #define for_each_bio(_bio) \
769 for (; _bio; _bio = _bio->bi_next)
770 #define __rq_for_each_bio(_bio, rq) \
772 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
774 #define rq_for_each_segment(bvl, _rq, _iter) \
775 __rq_for_each_bio(_iter.bio, _rq) \
776 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
778 #define rq_iter_last(bvec, _iter) \
779 (_iter.bio->bi_next == NULL && \
780 bio_iter_last(bvec, _iter.iter))
782 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
783 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
785 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
786 extern void rq_flush_dcache_pages(struct request *rq);
788 static inline void rq_flush_dcache_pages(struct request *rq)
793 extern int blk_register_queue(struct gendisk *disk);
794 extern void blk_unregister_queue(struct gendisk *disk);
795 extern void generic_make_request(struct bio *bio);
796 extern void blk_rq_init(struct request_queue *q, struct request *rq);
797 extern void blk_put_request(struct request *);
798 extern void __blk_put_request(struct request_queue *, struct request *);
799 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
800 extern struct request *blk_make_request(struct request_queue *, struct bio *,
802 extern void blk_rq_set_block_pc(struct request *);
803 extern void blk_requeue_request(struct request_queue *, struct request *);
804 extern void blk_add_request_payload(struct request *rq, struct page *page,
806 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
807 extern int blk_lld_busy(struct request_queue *q);
808 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
809 struct bio_set *bs, gfp_t gfp_mask,
810 int (*bio_ctr)(struct bio *, struct bio *, void *),
812 extern void blk_rq_unprep_clone(struct request *rq);
813 extern int blk_insert_cloned_request(struct request_queue *q,
815 extern void blk_delay_queue(struct request_queue *, unsigned long);
816 extern void blk_recount_segments(struct request_queue *, struct bio *);
817 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
818 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
819 unsigned int, void __user *);
820 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
821 unsigned int, void __user *);
822 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
823 struct scsi_ioctl_command __user *);
826 * A queue has just exitted congestion. Note this in the global counter of
827 * congested queues, and wake up anyone who was waiting for requests to be
830 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
832 clear_bdi_congested(&q->backing_dev_info, sync);
836 * A queue has just entered congestion. Flag that in the queue's VM-visible
837 * state flags and increment the global gounter of congested queues.
839 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
841 set_bdi_congested(&q->backing_dev_info, sync);
844 extern void blk_start_queue(struct request_queue *q);
845 extern void blk_stop_queue(struct request_queue *q);
846 extern void blk_sync_queue(struct request_queue *q);
847 extern void __blk_stop_queue(struct request_queue *q);
848 extern void __blk_run_queue(struct request_queue *q);
849 extern void blk_run_queue(struct request_queue *);
850 extern void blk_run_queue_async(struct request_queue *q);
851 extern int blk_rq_map_user(struct request_queue *, struct request *,
852 struct rq_map_data *, void __user *, unsigned long,
854 extern int blk_rq_unmap_user(struct bio *);
855 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
856 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
857 struct rq_map_data *, const struct iov_iter *,
859 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
860 struct request *, int);
861 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
862 struct request *, int, rq_end_io_fn *);
864 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
866 return bdev->bd_disk->queue; /* this is never NULL */
870 * blk_rq_pos() : the current sector
871 * blk_rq_bytes() : bytes left in the entire request
872 * blk_rq_cur_bytes() : bytes left in the current segment
873 * blk_rq_err_bytes() : bytes left till the next error boundary
874 * blk_rq_sectors() : sectors left in the entire request
875 * blk_rq_cur_sectors() : sectors left in the current segment
877 static inline sector_t blk_rq_pos(const struct request *rq)
882 static inline unsigned int blk_rq_bytes(const struct request *rq)
884 return rq->__data_len;
887 static inline int blk_rq_cur_bytes(const struct request *rq)
889 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
892 extern unsigned int blk_rq_err_bytes(const struct request *rq);
894 static inline unsigned int blk_rq_sectors(const struct request *rq)
896 return blk_rq_bytes(rq) >> 9;
899 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
901 return blk_rq_cur_bytes(rq) >> 9;
904 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
905 unsigned int cmd_flags)
907 if (unlikely(cmd_flags & REQ_DISCARD))
908 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
910 if (unlikely(cmd_flags & REQ_WRITE_SAME))
911 return q->limits.max_write_same_sectors;
913 return q->limits.max_sectors;
917 * Return maximum size of a request at given offset. Only valid for
918 * file system requests.
920 static inline unsigned int blk_max_size_offset(struct request_queue *q,
923 if (!q->limits.chunk_sectors)
924 return q->limits.max_sectors;
926 return q->limits.chunk_sectors -
927 (offset & (q->limits.chunk_sectors - 1));
930 static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
932 struct request_queue *q = rq->q;
934 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
935 return q->limits.max_hw_sectors;
937 if (!q->limits.chunk_sectors)
938 return blk_queue_get_max_sectors(q, rq->cmd_flags);
940 return min(blk_max_size_offset(q, blk_rq_pos(rq)),
941 blk_queue_get_max_sectors(q, rq->cmd_flags));
944 static inline unsigned int blk_rq_count_bios(struct request *rq)
946 unsigned int nr_bios = 0;
949 __rq_for_each_bio(bio, rq)
956 * Request issue related functions.
958 extern struct request *blk_peek_request(struct request_queue *q);
959 extern void blk_start_request(struct request *rq);
960 extern struct request *blk_fetch_request(struct request_queue *q);
963 * Request completion related functions.
965 * blk_update_request() completes given number of bytes and updates
966 * the request without completing it.
968 * blk_end_request() and friends. __blk_end_request() must be called
969 * with the request queue spinlock acquired.
971 * Several drivers define their own end_request and call
972 * blk_end_request() for parts of the original function.
973 * This prevents code duplication in drivers.
975 extern bool blk_update_request(struct request *rq, int error,
976 unsigned int nr_bytes);
977 extern void blk_finish_request(struct request *rq, int error);
978 extern bool blk_end_request(struct request *rq, int error,
979 unsigned int nr_bytes);
980 extern void blk_end_request_all(struct request *rq, int error);
981 extern bool blk_end_request_cur(struct request *rq, int error);
982 extern bool blk_end_request_err(struct request *rq, int error);
983 extern bool __blk_end_request(struct request *rq, int error,
984 unsigned int nr_bytes);
985 extern void __blk_end_request_all(struct request *rq, int error);
986 extern bool __blk_end_request_cur(struct request *rq, int error);
987 extern bool __blk_end_request_err(struct request *rq, int error);
989 extern void blk_complete_request(struct request *);
990 extern void __blk_complete_request(struct request *);
991 extern void blk_abort_request(struct request *);
992 extern void blk_unprep_request(struct request *);
995 * Access functions for manipulating queue properties
997 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
998 spinlock_t *lock, int node_id);
999 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
1000 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
1001 request_fn_proc *, spinlock_t *);
1002 extern void blk_cleanup_queue(struct request_queue *);
1003 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1004 extern void blk_queue_bounce_limit(struct request_queue *, u64);
1005 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
1006 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1007 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1008 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1009 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1010 extern void blk_queue_max_discard_sectors(struct request_queue *q,
1011 unsigned int max_discard_sectors);
1012 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1013 unsigned int max_write_same_sectors);
1014 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
1015 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1016 extern void blk_queue_alignment_offset(struct request_queue *q,
1017 unsigned int alignment);
1018 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1019 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1020 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1021 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1022 extern void blk_set_default_limits(struct queue_limits *lim);
1023 extern void blk_set_stacking_limits(struct queue_limits *lim);
1024 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1026 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1028 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1030 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1031 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1032 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1033 extern int blk_queue_dma_drain(struct request_queue *q,
1034 dma_drain_needed_fn *dma_drain_needed,
1035 void *buf, unsigned int size);
1036 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1037 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1038 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1039 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
1040 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
1041 extern void blk_queue_dma_alignment(struct request_queue *, int);
1042 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1043 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1044 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1045 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1046 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
1047 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1048 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1050 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1051 extern void blk_dump_rq_flags(struct request *, char *);
1052 extern long nr_blockdev_pages(void);
1054 bool __must_check blk_get_queue(struct request_queue *);
1055 struct request_queue *blk_alloc_queue(gfp_t);
1056 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1057 extern void blk_put_queue(struct request_queue *);
1060 * block layer runtime pm functions
1063 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1064 extern int blk_pre_runtime_suspend(struct request_queue *q);
1065 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1066 extern void blk_pre_runtime_resume(struct request_queue *q);
1067 extern void blk_post_runtime_resume(struct request_queue *q, int err);
1069 static inline void blk_pm_runtime_init(struct request_queue *q,
1070 struct device *dev) {}
1071 static inline int blk_pre_runtime_suspend(struct request_queue *q)
1075 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1076 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1077 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1081 * blk_plug permits building a queue of related requests by holding the I/O
1082 * fragments for a short period. This allows merging of sequential requests
1083 * into single larger request. As the requests are moved from a per-task list to
1084 * the device's request_queue in a batch, this results in improved scalability
1085 * as the lock contention for request_queue lock is reduced.
1087 * It is ok not to disable preemption when adding the request to the plug list
1088 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1089 * the plug list when the task sleeps by itself. For details, please see
1090 * schedule() where blk_schedule_flush_plug() is called.
1093 struct list_head list; /* requests */
1094 struct list_head mq_list; /* blk-mq requests */
1095 struct list_head cb_list; /* md requires an unplug callback */
1097 #define BLK_MAX_REQUEST_COUNT 16
1100 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1101 struct blk_plug_cb {
1102 struct list_head list;
1103 blk_plug_cb_fn callback;
1106 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1107 void *data, int size);
1108 extern void blk_start_plug(struct blk_plug *);
1109 extern void blk_finish_plug(struct blk_plug *);
1110 extern void blk_flush_plug_list(struct blk_plug *, bool);
1112 static inline void blk_flush_plug(struct task_struct *tsk)
1114 struct blk_plug *plug = tsk->plug;
1117 blk_flush_plug_list(plug, false);
1120 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1122 struct blk_plug *plug = tsk->plug;
1125 blk_flush_plug_list(plug, true);
1128 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1130 struct blk_plug *plug = tsk->plug;
1133 (!list_empty(&plug->list) ||
1134 !list_empty(&plug->mq_list) ||
1135 !list_empty(&plug->cb_list));
1141 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1142 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1143 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1144 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
1145 extern void blk_queue_free_tags(struct request_queue *);
1146 extern int blk_queue_resize_tags(struct request_queue *, int);
1147 extern void blk_queue_invalidate_tags(struct request_queue *);
1148 extern struct blk_queue_tag *blk_init_tags(int, int);
1149 extern void blk_free_tags(struct blk_queue_tag *);
1151 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1154 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1156 return bqt->tag_index[tag];
1159 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1161 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1162 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1163 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1164 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1165 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1166 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1167 sector_t nr_sects, gfp_t gfp_mask, bool discard);
1168 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1169 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1171 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1172 nr_blocks << (sb->s_blocksize_bits - 9),
1175 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1176 sector_t nr_blocks, gfp_t gfp_mask)
1178 return blkdev_issue_zeroout(sb->s_bdev,
1179 block << (sb->s_blocksize_bits - 9),
1180 nr_blocks << (sb->s_blocksize_bits - 9),
1184 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1186 enum blk_default_limits {
1187 BLK_MAX_SEGMENTS = 128,
1188 BLK_SAFE_MAX_SECTORS = 255,
1189 BLK_MAX_SEGMENT_SIZE = 65536,
1190 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1193 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1195 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1197 return q->limits.bounce_pfn;
1200 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1202 return q->limits.seg_boundary_mask;
1205 static inline unsigned int queue_max_sectors(struct request_queue *q)
1207 return q->limits.max_sectors;
1210 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1212 return q->limits.max_hw_sectors;
1215 static inline unsigned short queue_max_segments(struct request_queue *q)
1217 return q->limits.max_segments;
1220 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1222 return q->limits.max_segment_size;
1225 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1229 if (q && q->limits.logical_block_size)
1230 retval = q->limits.logical_block_size;
1235 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1237 return queue_logical_block_size(bdev_get_queue(bdev));
1240 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1242 return q->limits.physical_block_size;
1245 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1247 return queue_physical_block_size(bdev_get_queue(bdev));
1250 static inline unsigned int queue_io_min(struct request_queue *q)
1252 return q->limits.io_min;
1255 static inline int bdev_io_min(struct block_device *bdev)
1257 return queue_io_min(bdev_get_queue(bdev));
1260 static inline unsigned int queue_io_opt(struct request_queue *q)
1262 return q->limits.io_opt;
1265 static inline int bdev_io_opt(struct block_device *bdev)
1267 return queue_io_opt(bdev_get_queue(bdev));
1270 static inline int queue_alignment_offset(struct request_queue *q)
1272 if (q->limits.misaligned)
1275 return q->limits.alignment_offset;
1278 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1280 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1281 unsigned int alignment = sector_div(sector, granularity >> 9) << 9;
1283 return (granularity + lim->alignment_offset - alignment) % granularity;
1286 static inline int bdev_alignment_offset(struct block_device *bdev)
1288 struct request_queue *q = bdev_get_queue(bdev);
1290 if (q->limits.misaligned)
1293 if (bdev != bdev->bd_contains)
1294 return bdev->bd_part->alignment_offset;
1296 return q->limits.alignment_offset;
1299 static inline int queue_discard_alignment(struct request_queue *q)
1301 if (q->limits.discard_misaligned)
1304 return q->limits.discard_alignment;
1307 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1309 unsigned int alignment, granularity, offset;
1311 if (!lim->max_discard_sectors)
1314 /* Why are these in bytes, not sectors? */
1315 alignment = lim->discard_alignment >> 9;
1316 granularity = lim->discard_granularity >> 9;
1320 /* Offset of the partition start in 'granularity' sectors */
1321 offset = sector_div(sector, granularity);
1323 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1324 offset = (granularity + alignment - offset) % granularity;
1326 /* Turn it back into bytes, gaah */
1330 static inline int bdev_discard_alignment(struct block_device *bdev)
1332 struct request_queue *q = bdev_get_queue(bdev);
1334 if (bdev != bdev->bd_contains)
1335 return bdev->bd_part->discard_alignment;
1337 return q->limits.discard_alignment;
1340 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1342 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1348 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1350 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1353 static inline unsigned int bdev_write_same(struct block_device *bdev)
1355 struct request_queue *q = bdev_get_queue(bdev);
1358 return q->limits.max_write_same_sectors;
1363 static inline int queue_dma_alignment(struct request_queue *q)
1365 return q ? q->dma_alignment : 511;
1368 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1371 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1372 return !(addr & alignment) && !(len & alignment);
1375 /* assumes size > 256 */
1376 static inline unsigned int blksize_bits(unsigned int size)
1378 unsigned int bits = 8;
1382 } while (size > 256);
1386 static inline unsigned int block_size(struct block_device *bdev)
1388 return bdev->bd_block_size;
1391 static inline bool queue_flush_queueable(struct request_queue *q)
1393 return !q->flush_not_queueable;
1396 typedef struct {struct page *v;} Sector;
1398 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1400 static inline void put_dev_sector(Sector p)
1402 page_cache_release(p.v);
1406 int kblockd_schedule_work(struct work_struct *work);
1407 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
1408 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1410 #ifdef CONFIG_BLK_CGROUP
1412 * This should not be using sched_clock(). A real patch is in progress
1413 * to fix this up, until that is in place we need to disable preemption
1414 * around sched_clock() in this function and set_io_start_time_ns().
1416 static inline void set_start_time_ns(struct request *req)
1419 req->start_time_ns = sched_clock();
1423 static inline void set_io_start_time_ns(struct request *req)
1426 req->io_start_time_ns = sched_clock();
1430 static inline uint64_t rq_start_time_ns(struct request *req)
1432 return req->start_time_ns;
1435 static inline uint64_t rq_io_start_time_ns(struct request *req)
1437 return req->io_start_time_ns;
1440 static inline void set_start_time_ns(struct request *req) {}
1441 static inline void set_io_start_time_ns(struct request *req) {}
1442 static inline uint64_t rq_start_time_ns(struct request *req)
1446 static inline uint64_t rq_io_start_time_ns(struct request *req)
1452 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1453 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1454 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1455 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1457 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1459 enum blk_integrity_flags {
1460 BLK_INTEGRITY_VERIFY = 1 << 0,
1461 BLK_INTEGRITY_GENERATE = 1 << 1,
1462 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2,
1463 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3,
1466 struct blk_integrity_iter {
1470 unsigned int data_size;
1471 unsigned short interval;
1472 const char *disk_name;
1475 typedef int (integrity_processing_fn) (struct blk_integrity_iter *);
1477 struct blk_integrity {
1478 integrity_processing_fn *generate_fn;
1479 integrity_processing_fn *verify_fn;
1481 unsigned short flags;
1482 unsigned short tuple_size;
1483 unsigned short interval;
1484 unsigned short tag_size;
1488 struct kobject kobj;
1491 extern bool blk_integrity_is_initialized(struct gendisk *);
1492 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1493 extern void blk_integrity_unregister(struct gendisk *);
1494 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1495 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1496 struct scatterlist *);
1497 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1498 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
1500 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
1504 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1506 return bdev->bd_disk->integrity;
1509 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1511 return disk->integrity;
1514 static inline bool blk_integrity_rq(struct request *rq)
1516 return rq->cmd_flags & REQ_INTEGRITY;
1519 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1522 q->limits.max_integrity_segments = segs;
1525 static inline unsigned short
1526 queue_max_integrity_segments(struct request_queue *q)
1528 return q->limits.max_integrity_segments;
1531 #else /* CONFIG_BLK_DEV_INTEGRITY */
1534 struct block_device;
1536 struct blk_integrity;
1538 static inline int blk_integrity_rq(struct request *rq)
1542 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1547 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1549 struct scatterlist *s)
1553 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1557 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1561 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1565 static inline int blk_integrity_register(struct gendisk *d,
1566 struct blk_integrity *b)
1570 static inline void blk_integrity_unregister(struct gendisk *d)
1573 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1577 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1581 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
1587 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
1593 static inline bool blk_integrity_is_initialized(struct gendisk *g)
1598 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1600 struct block_device_operations {
1601 int (*open) (struct block_device *, fmode_t);
1602 void (*release) (struct gendisk *, fmode_t);
1603 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
1604 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1605 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1606 long (*direct_access)(struct block_device *, sector_t,
1607 void **, unsigned long *pfn, long size);
1608 unsigned int (*check_events) (struct gendisk *disk,
1609 unsigned int clearing);
1610 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1611 int (*media_changed) (struct gendisk *);
1612 void (*unlock_native_capacity) (struct gendisk *);
1613 int (*revalidate_disk) (struct gendisk *);
1614 int (*getgeo)(struct block_device *, struct hd_geometry *);
1615 /* this callback is with swap_lock and sometimes page table lock held */
1616 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1617 struct module *owner;
1620 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1622 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1623 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1624 struct writeback_control *);
1625 extern long bdev_direct_access(struct block_device *, sector_t, void **addr,
1626 unsigned long *pfn, long size);
1627 #else /* CONFIG_BLOCK */
1629 struct block_device;
1632 * stubs for when the block layer is configured out
1634 #define buffer_heads_over_limit 0
1636 static inline long nr_blockdev_pages(void)
1644 static inline void blk_start_plug(struct blk_plug *plug)
1648 static inline void blk_finish_plug(struct blk_plug *plug)
1652 static inline void blk_flush_plug(struct task_struct *task)
1656 static inline void blk_schedule_flush_plug(struct task_struct *task)
1661 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1666 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1667 sector_t *error_sector)
1672 #endif /* CONFIG_BLOCK */