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/timer.h>
12 #include <linux/workqueue.h>
13 #include <linux/pagemap.h>
14 #include <linux/backing-dev.h>
15 #include <linux/wait.h>
16 #include <linux/mempool.h>
17 #include <linux/bio.h>
18 #include <linux/stringify.h>
19 #include <linux/gfp.h>
20 #include <linux/bsg.h>
21 #include <linux/smp.h>
23 #include <asm/scatterlist.h>
26 struct scsi_ioctl_command
;
29 struct elevator_queue
;
30 struct request_pm_state
;
37 #define BLKDEV_MIN_RQ 4
38 #define BLKDEV_MAX_RQ 128 /* Default maximum */
41 * Maximum number of blkcg policies allowed to be registered concurrently.
42 * Defined here to simplify include dependency.
44 #define BLKCG_MAX_POLS 2
47 typedef void (rq_end_io_fn
)(struct request
*, int);
49 #define BLK_RL_SYNCFULL (1U << 0)
50 #define BLK_RL_ASYNCFULL (1U << 1)
53 struct request_queue
*q
; /* the queue this rl belongs to */
54 #ifdef CONFIG_BLK_CGROUP
55 struct blkcg_gq
*blkg
; /* blkg this request pool belongs to */
58 * count[], starved[], and wait[] are indexed by
59 * BLK_RW_SYNC/BLK_RW_ASYNC
64 wait_queue_head_t wait
[2];
69 * request command types
71 enum rq_cmd_type_bits
{
72 REQ_TYPE_FS
= 1, /* fs request */
73 REQ_TYPE_BLOCK_PC
, /* scsi command */
74 REQ_TYPE_SENSE
, /* sense request */
75 REQ_TYPE_PM_SUSPEND
, /* suspend request */
76 REQ_TYPE_PM_RESUME
, /* resume request */
77 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
78 REQ_TYPE_SPECIAL
, /* driver defined type */
80 * for ATA/ATAPI devices. this really doesn't belong here, ide should
81 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
82 * private REQ_LB opcodes to differentiate what type of request this is
84 REQ_TYPE_ATA_TASKFILE
,
88 #define BLK_MAX_CDB 16
91 * try to put the fields that are referenced together in the same cacheline.
92 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
96 struct list_head queuelist
;
97 struct call_single_data csd
;
99 struct request_queue
*q
;
101 unsigned int cmd_flags
;
102 enum rq_cmd_type_bits cmd_type
;
103 unsigned long atomic_flags
;
107 /* the following two fields are internal, NEVER access directly */
108 unsigned int __data_len
; /* total data len */
109 sector_t __sector
; /* sector cursor */
114 struct hlist_node hash
; /* merge hash */
116 * The rb_node is only used inside the io scheduler, requests
117 * are pruned when moved to the dispatch queue. So let the
118 * completion_data share space with the rb_node.
121 struct rb_node rb_node
; /* sort/lookup */
122 void *completion_data
;
126 * Three pointers are available for the IO schedulers, if they need
127 * more they have to dynamically allocate it. Flush requests are
128 * never put on the IO scheduler. So let the flush fields share
129 * space with the elevator data.
139 struct list_head list
;
140 rq_end_io_fn
*saved_end_io
;
144 struct gendisk
*rq_disk
;
145 struct hd_struct
*part
;
146 unsigned long start_time
;
147 #ifdef CONFIG_BLK_CGROUP
148 struct request_list
*rl
; /* rl this rq is alloced from */
149 unsigned long long start_time_ns
;
150 unsigned long long io_start_time_ns
; /* when passed to hardware */
152 /* Number of scatter-gather DMA addr+len pairs after
153 * physical address coalescing is performed.
155 unsigned short nr_phys_segments
;
156 #if defined(CONFIG_BLK_DEV_INTEGRITY)
157 unsigned short nr_integrity_segments
;
160 unsigned short ioprio
;
164 void *special
; /* opaque pointer available for LLD use */
165 char *buffer
; /* kaddr of the current segment if available */
171 * when request is used as a packet command carrier
173 unsigned char __cmd
[BLK_MAX_CDB
];
175 unsigned short cmd_len
;
177 unsigned int extra_len
; /* length of alignment and padding */
178 unsigned int sense_len
;
179 unsigned int resid_len
; /* residual count */
182 unsigned long deadline
;
183 struct list_head timeout_list
;
184 unsigned int timeout
;
188 * completion callback.
190 rq_end_io_fn
*end_io
;
194 struct request
*next_rq
;
197 static inline unsigned short req_get_ioprio(struct request
*req
)
203 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
204 * requests. Some step values could eventually be made generic.
206 struct request_pm_state
208 /* PM state machine step value, currently driver specific */
210 /* requested PM state value (S1, S2, S3, S4, ...) */
212 void* data
; /* for driver use */
215 #include <linux/elevator.h>
217 typedef void (request_fn_proc
) (struct request_queue
*q
);
218 typedef void (make_request_fn
) (struct request_queue
*q
, struct bio
*bio
);
219 typedef int (prep_rq_fn
) (struct request_queue
*, struct request
*);
220 typedef void (unprep_rq_fn
) (struct request_queue
*, struct request
*);
223 struct bvec_merge_data
{
224 struct block_device
*bi_bdev
;
229 typedef int (merge_bvec_fn
) (struct request_queue
*, struct bvec_merge_data
*,
231 typedef void (softirq_done_fn
)(struct request
*);
232 typedef int (dma_drain_needed_fn
)(struct request
*);
233 typedef int (lld_busy_fn
) (struct request_queue
*q
);
234 typedef int (bsg_job_fn
) (struct bsg_job
*);
236 enum blk_eh_timer_return
{
242 typedef enum blk_eh_timer_return (rq_timed_out_fn
)(struct request
*);
244 enum blk_queue_state
{
249 struct blk_queue_tag
{
250 struct request
**tag_index
; /* map of busy tags */
251 unsigned long *tag_map
; /* bit map of free/busy tags */
252 int busy
; /* current depth */
253 int max_depth
; /* what we will send to device */
254 int real_max_depth
; /* what the array can hold */
255 atomic_t refcnt
; /* map can be shared */
258 #define BLK_SCSI_MAX_CMDS (256)
259 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
261 struct queue_limits
{
262 unsigned long bounce_pfn
;
263 unsigned long seg_boundary_mask
;
265 unsigned int max_hw_sectors
;
266 unsigned int max_sectors
;
267 unsigned int max_segment_size
;
268 unsigned int physical_block_size
;
269 unsigned int alignment_offset
;
272 unsigned int max_discard_sectors
;
273 unsigned int max_write_same_sectors
;
274 unsigned int discard_granularity
;
275 unsigned int discard_alignment
;
277 unsigned short logical_block_size
;
278 unsigned short max_segments
;
279 unsigned short max_integrity_segments
;
281 unsigned char misaligned
;
282 unsigned char discard_misaligned
;
283 unsigned char cluster
;
284 unsigned char discard_zeroes_data
;
287 struct request_queue
{
289 * Together with queue_head for cacheline sharing
291 struct list_head queue_head
;
292 struct request
*last_merge
;
293 struct elevator_queue
*elevator
;
294 int nr_rqs
[2]; /* # allocated [a]sync rqs */
295 int nr_rqs_elvpriv
; /* # allocated rqs w/ elvpriv */
298 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
299 * is used, root blkg allocates from @q->root_rl and all other
300 * blkgs from their own blkg->rl. Which one to use should be
301 * determined using bio_request_list().
303 struct request_list root_rl
;
305 request_fn_proc
*request_fn
;
306 make_request_fn
*make_request_fn
;
307 prep_rq_fn
*prep_rq_fn
;
308 unprep_rq_fn
*unprep_rq_fn
;
309 merge_bvec_fn
*merge_bvec_fn
;
310 softirq_done_fn
*softirq_done_fn
;
311 rq_timed_out_fn
*rq_timed_out_fn
;
312 dma_drain_needed_fn
*dma_drain_needed
;
313 lld_busy_fn
*lld_busy_fn
;
316 * Dispatch queue sorting
319 struct request
*boundary_rq
;
322 * Delayed queue handling
324 struct delayed_work delay_work
;
326 struct backing_dev_info backing_dev_info
;
329 * The queue owner gets to use this for whatever they like.
330 * ll_rw_blk doesn't touch it.
335 * various queue flags, see QUEUE_* below
337 unsigned long queue_flags
;
340 * ida allocated id for this queue. Used to index queues from
346 * queue needs bounce pages for pages above this limit
351 * protects queue structures from reentrancy. ->__queue_lock should
352 * _never_ be used directly, it is queue private. always use
355 spinlock_t __queue_lock
;
356 spinlock_t
*queue_lock
;
366 unsigned long nr_requests
; /* Max # of requests */
367 unsigned int nr_congestion_on
;
368 unsigned int nr_congestion_off
;
369 unsigned int nr_batching
;
371 unsigned int dma_drain_size
;
372 void *dma_drain_buffer
;
373 unsigned int dma_pad_mask
;
374 unsigned int dma_alignment
;
376 struct blk_queue_tag
*queue_tags
;
377 struct list_head tag_busy_list
;
379 unsigned int nr_sorted
;
380 unsigned int in_flight
[2];
382 * Number of active block driver functions for which blk_drain_queue()
383 * must wait. Must be incremented around functions that unlock the
384 * queue_lock internally, e.g. scsi_request_fn().
386 unsigned int request_fn_active
;
388 unsigned int rq_timeout
;
389 struct timer_list timeout
;
390 struct list_head timeout_list
;
392 struct list_head icq_list
;
393 #ifdef CONFIG_BLK_CGROUP
394 DECLARE_BITMAP (blkcg_pols
, BLKCG_MAX_POLS
);
395 struct blkcg_gq
*root_blkg
;
396 struct list_head blkg_list
;
399 struct queue_limits limits
;
404 unsigned int sg_timeout
;
405 unsigned int sg_reserved_size
;
407 #ifdef CONFIG_BLK_DEV_IO_TRACE
408 struct blk_trace
*blk_trace
;
411 * for flush operations
413 unsigned int flush_flags
;
414 unsigned int flush_not_queueable
:1;
415 unsigned int flush_queue_delayed
:1;
416 unsigned int flush_pending_idx
:1;
417 unsigned int flush_running_idx
:1;
418 unsigned long flush_pending_since
;
419 struct list_head flush_queue
[2];
420 struct list_head flush_data_in_flight
;
421 struct request flush_rq
;
423 struct mutex sysfs_lock
;
427 #if defined(CONFIG_BLK_DEV_BSG)
428 bsg_job_fn
*bsg_job_fn
;
430 struct bsg_class_device bsg_dev
;
433 #ifdef CONFIG_BLK_CGROUP
434 struct list_head all_q_node
;
436 #ifdef CONFIG_BLK_DEV_THROTTLING
438 struct throtl_data
*td
;
442 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
443 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
444 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
445 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
446 #define QUEUE_FLAG_DYING 5 /* queue being torn down */
447 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
448 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
449 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
450 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
451 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
452 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
453 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
454 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
455 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
456 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
457 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
458 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
459 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
460 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
461 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
463 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
464 (1 << QUEUE_FLAG_STACKABLE) | \
465 (1 << QUEUE_FLAG_SAME_COMP) | \
466 (1 << QUEUE_FLAG_ADD_RANDOM))
468 static inline void queue_lockdep_assert_held(struct request_queue
*q
)
471 lockdep_assert_held(q
->queue_lock
);
474 static inline void queue_flag_set_unlocked(unsigned int flag
,
475 struct request_queue
*q
)
477 __set_bit(flag
, &q
->queue_flags
);
480 static inline int queue_flag_test_and_clear(unsigned int flag
,
481 struct request_queue
*q
)
483 queue_lockdep_assert_held(q
);
485 if (test_bit(flag
, &q
->queue_flags
)) {
486 __clear_bit(flag
, &q
->queue_flags
);
493 static inline int queue_flag_test_and_set(unsigned int flag
,
494 struct request_queue
*q
)
496 queue_lockdep_assert_held(q
);
498 if (!test_bit(flag
, &q
->queue_flags
)) {
499 __set_bit(flag
, &q
->queue_flags
);
506 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
508 queue_lockdep_assert_held(q
);
509 __set_bit(flag
, &q
->queue_flags
);
512 static inline void queue_flag_clear_unlocked(unsigned int flag
,
513 struct request_queue
*q
)
515 __clear_bit(flag
, &q
->queue_flags
);
518 static inline int queue_in_flight(struct request_queue
*q
)
520 return q
->in_flight
[0] + q
->in_flight
[1];
523 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
525 queue_lockdep_assert_held(q
);
526 __clear_bit(flag
, &q
->queue_flags
);
529 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
530 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
531 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
532 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
533 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
534 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
535 #define blk_queue_noxmerges(q) \
536 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
537 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
538 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
539 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
540 #define blk_queue_stackable(q) \
541 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
542 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
543 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
544 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
546 #define blk_noretry_request(rq) \
547 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
548 REQ_FAILFAST_DRIVER))
550 #define blk_account_rq(rq) \
551 (((rq)->cmd_flags & REQ_STARTED) && \
552 ((rq)->cmd_type == REQ_TYPE_FS))
554 #define blk_pm_request(rq) \
555 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
556 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
558 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
559 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
560 /* rq->queuelist of dequeued request must be list_empty() */
561 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
563 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
565 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
567 static inline unsigned int blk_queue_cluster(struct request_queue
*q
)
569 return q
->limits
.cluster
;
573 * We regard a request as sync, if either a read or a sync write
575 static inline bool rw_is_sync(unsigned int rw_flags
)
577 return !(rw_flags
& REQ_WRITE
) || (rw_flags
& REQ_SYNC
);
580 static inline bool rq_is_sync(struct request
*rq
)
582 return rw_is_sync(rq
->cmd_flags
);
585 static inline bool blk_rl_full(struct request_list
*rl
, bool sync
)
587 unsigned int flag
= sync
? BLK_RL_SYNCFULL
: BLK_RL_ASYNCFULL
;
589 return rl
->flags
& flag
;
592 static inline void blk_set_rl_full(struct request_list
*rl
, bool sync
)
594 unsigned int flag
= sync
? BLK_RL_SYNCFULL
: BLK_RL_ASYNCFULL
;
599 static inline void blk_clear_rl_full(struct request_list
*rl
, bool sync
)
601 unsigned int flag
= sync
? BLK_RL_SYNCFULL
: BLK_RL_ASYNCFULL
;
606 static inline bool rq_mergeable(struct request
*rq
)
608 if (rq
->cmd_type
!= REQ_TYPE_FS
)
611 if (rq
->cmd_flags
& REQ_NOMERGE_FLAGS
)
617 static inline bool blk_check_merge_flags(unsigned int flags1
,
620 if ((flags1
& REQ_DISCARD
) != (flags2
& REQ_DISCARD
))
623 if ((flags1
& REQ_SECURE
) != (flags2
& REQ_SECURE
))
626 if ((flags1
& REQ_WRITE_SAME
) != (flags2
& REQ_WRITE_SAME
))
632 static inline bool blk_write_same_mergeable(struct bio
*a
, struct bio
*b
)
634 if (bio_data(a
) == bio_data(b
))
641 * q->prep_rq_fn return values
643 #define BLKPREP_OK 0 /* serve it */
644 #define BLKPREP_KILL 1 /* fatal error, kill */
645 #define BLKPREP_DEFER 2 /* leave on queue */
647 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
650 * standard bounce addresses:
652 * BLK_BOUNCE_HIGH : bounce all highmem pages
653 * BLK_BOUNCE_ANY : don't bounce anything
654 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
657 #if BITS_PER_LONG == 32
658 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
660 #define BLK_BOUNCE_HIGH -1ULL
662 #define BLK_BOUNCE_ANY (-1ULL)
663 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
666 * default timeout for SG_IO if none specified
668 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
669 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
672 extern int init_emergency_isa_pool(void);
673 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
675 static inline int init_emergency_isa_pool(void)
679 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
682 #endif /* CONFIG_MMU */
688 unsigned long offset
;
693 struct req_iterator
{
698 /* This should not be used directly - use rq_for_each_segment */
699 #define for_each_bio(_bio) \
700 for (; _bio; _bio = _bio->bi_next)
701 #define __rq_for_each_bio(_bio, rq) \
703 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
705 #define rq_for_each_segment(bvl, _rq, _iter) \
706 __rq_for_each_bio(_iter.bio, _rq) \
707 bio_for_each_segment(bvl, _iter.bio, _iter.i)
709 #define rq_iter_last(rq, _iter) \
710 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
712 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
713 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
715 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
716 extern void rq_flush_dcache_pages(struct request
*rq
);
718 static inline void rq_flush_dcache_pages(struct request
*rq
)
723 extern int blk_register_queue(struct gendisk
*disk
);
724 extern void blk_unregister_queue(struct gendisk
*disk
);
725 extern void generic_make_request(struct bio
*bio
);
726 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
727 extern void blk_put_request(struct request
*);
728 extern void __blk_put_request(struct request_queue
*, struct request
*);
729 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
730 extern struct request
*blk_make_request(struct request_queue
*, struct bio
*,
732 extern void blk_requeue_request(struct request_queue
*, struct request
*);
733 extern void blk_add_request_payload(struct request
*rq
, struct page
*page
,
735 extern int blk_rq_check_limits(struct request_queue
*q
, struct request
*rq
);
736 extern int blk_lld_busy(struct request_queue
*q
);
737 extern int blk_rq_prep_clone(struct request
*rq
, struct request
*rq_src
,
738 struct bio_set
*bs
, gfp_t gfp_mask
,
739 int (*bio_ctr
)(struct bio
*, struct bio
*, void *),
741 extern void blk_rq_unprep_clone(struct request
*rq
);
742 extern int blk_insert_cloned_request(struct request_queue
*q
,
744 extern void blk_delay_queue(struct request_queue
*, unsigned long);
745 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
746 extern int scsi_verify_blk_ioctl(struct block_device
*, unsigned int);
747 extern int scsi_cmd_blk_ioctl(struct block_device
*, fmode_t
,
748 unsigned int, void __user
*);
749 extern int scsi_cmd_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
750 unsigned int, void __user
*);
751 extern int sg_scsi_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
752 struct scsi_ioctl_command __user
*);
754 extern void blk_queue_bio(struct request_queue
*q
, struct bio
*bio
);
757 * A queue has just exitted congestion. Note this in the global counter of
758 * congested queues, and wake up anyone who was waiting for requests to be
761 static inline void blk_clear_queue_congested(struct request_queue
*q
, int sync
)
763 clear_bdi_congested(&q
->backing_dev_info
, sync
);
767 * A queue has just entered congestion. Flag that in the queue's VM-visible
768 * state flags and increment the global gounter of congested queues.
770 static inline void blk_set_queue_congested(struct request_queue
*q
, int sync
)
772 set_bdi_congested(&q
->backing_dev_info
, sync
);
775 extern void blk_start_queue(struct request_queue
*q
);
776 extern void blk_stop_queue(struct request_queue
*q
);
777 extern void blk_sync_queue(struct request_queue
*q
);
778 extern void __blk_stop_queue(struct request_queue
*q
);
779 extern void __blk_run_queue(struct request_queue
*q
);
780 extern void blk_run_queue(struct request_queue
*);
781 extern void blk_run_queue_async(struct request_queue
*q
);
782 extern int blk_rq_map_user(struct request_queue
*, struct request
*,
783 struct rq_map_data
*, void __user
*, unsigned long,
785 extern int blk_rq_unmap_user(struct bio
*);
786 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
787 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
788 struct rq_map_data
*, struct sg_iovec
*, int,
789 unsigned int, gfp_t
);
790 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
791 struct request
*, int);
792 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
793 struct request
*, int, rq_end_io_fn
*);
795 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
797 return bdev
->bd_disk
->queue
;
801 * blk_rq_pos() : the current sector
802 * blk_rq_bytes() : bytes left in the entire request
803 * blk_rq_cur_bytes() : bytes left in the current segment
804 * blk_rq_err_bytes() : bytes left till the next error boundary
805 * blk_rq_sectors() : sectors left in the entire request
806 * blk_rq_cur_sectors() : sectors left in the current segment
808 static inline sector_t
blk_rq_pos(const struct request
*rq
)
813 static inline unsigned int blk_rq_bytes(const struct request
*rq
)
815 return rq
->__data_len
;
818 static inline int blk_rq_cur_bytes(const struct request
*rq
)
820 return rq
->bio
? bio_cur_bytes(rq
->bio
) : 0;
823 extern unsigned int blk_rq_err_bytes(const struct request
*rq
);
825 static inline unsigned int blk_rq_sectors(const struct request
*rq
)
827 return blk_rq_bytes(rq
) >> 9;
830 static inline unsigned int blk_rq_cur_sectors(const struct request
*rq
)
832 return blk_rq_cur_bytes(rq
) >> 9;
835 static inline unsigned int blk_queue_get_max_sectors(struct request_queue
*q
,
836 unsigned int cmd_flags
)
838 if (unlikely(cmd_flags
& REQ_DISCARD
))
839 return q
->limits
.max_discard_sectors
;
841 if (unlikely(cmd_flags
& REQ_WRITE_SAME
))
842 return q
->limits
.max_write_same_sectors
;
844 return q
->limits
.max_sectors
;
847 static inline unsigned int blk_rq_get_max_sectors(struct request
*rq
)
849 struct request_queue
*q
= rq
->q
;
851 if (unlikely(rq
->cmd_type
== REQ_TYPE_BLOCK_PC
))
852 return q
->limits
.max_hw_sectors
;
854 return blk_queue_get_max_sectors(q
, rq
->cmd_flags
);
858 * Request issue related functions.
860 extern struct request
*blk_peek_request(struct request_queue
*q
);
861 extern void blk_start_request(struct request
*rq
);
862 extern struct request
*blk_fetch_request(struct request_queue
*q
);
865 * Request completion related functions.
867 * blk_update_request() completes given number of bytes and updates
868 * the request without completing it.
870 * blk_end_request() and friends. __blk_end_request() must be called
871 * with the request queue spinlock acquired.
873 * Several drivers define their own end_request and call
874 * blk_end_request() for parts of the original function.
875 * This prevents code duplication in drivers.
877 extern bool blk_update_request(struct request
*rq
, int error
,
878 unsigned int nr_bytes
);
879 extern bool blk_end_request(struct request
*rq
, int error
,
880 unsigned int nr_bytes
);
881 extern void blk_end_request_all(struct request
*rq
, int error
);
882 extern bool blk_end_request_cur(struct request
*rq
, int error
);
883 extern bool blk_end_request_err(struct request
*rq
, int error
);
884 extern bool __blk_end_request(struct request
*rq
, int error
,
885 unsigned int nr_bytes
);
886 extern void __blk_end_request_all(struct request
*rq
, int error
);
887 extern bool __blk_end_request_cur(struct request
*rq
, int error
);
888 extern bool __blk_end_request_err(struct request
*rq
, int error
);
890 extern void blk_complete_request(struct request
*);
891 extern void __blk_complete_request(struct request
*);
892 extern void blk_abort_request(struct request
*);
893 extern void blk_unprep_request(struct request
*);
896 * Access functions for manipulating queue properties
898 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
899 spinlock_t
*lock
, int node_id
);
900 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
901 extern struct request_queue
*blk_init_allocated_queue(struct request_queue
*,
902 request_fn_proc
*, spinlock_t
*);
903 extern void blk_cleanup_queue(struct request_queue
*);
904 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
905 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
906 extern void blk_limits_max_hw_sectors(struct queue_limits
*, unsigned int);
907 extern void blk_queue_max_hw_sectors(struct request_queue
*, unsigned int);
908 extern void blk_queue_max_segments(struct request_queue
*, unsigned short);
909 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
910 extern void blk_queue_max_discard_sectors(struct request_queue
*q
,
911 unsigned int max_discard_sectors
);
912 extern void blk_queue_max_write_same_sectors(struct request_queue
*q
,
913 unsigned int max_write_same_sectors
);
914 extern void blk_queue_logical_block_size(struct request_queue
*, unsigned short);
915 extern void blk_queue_physical_block_size(struct request_queue
*, unsigned int);
916 extern void blk_queue_alignment_offset(struct request_queue
*q
,
917 unsigned int alignment
);
918 extern void blk_limits_io_min(struct queue_limits
*limits
, unsigned int min
);
919 extern void blk_queue_io_min(struct request_queue
*q
, unsigned int min
);
920 extern void blk_limits_io_opt(struct queue_limits
*limits
, unsigned int opt
);
921 extern void blk_queue_io_opt(struct request_queue
*q
, unsigned int opt
);
922 extern void blk_set_default_limits(struct queue_limits
*lim
);
923 extern void blk_set_stacking_limits(struct queue_limits
*lim
);
924 extern int blk_stack_limits(struct queue_limits
*t
, struct queue_limits
*b
,
926 extern int bdev_stack_limits(struct queue_limits
*t
, struct block_device
*bdev
,
928 extern void disk_stack_limits(struct gendisk
*disk
, struct block_device
*bdev
,
930 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
931 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
932 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
933 extern int blk_queue_dma_drain(struct request_queue
*q
,
934 dma_drain_needed_fn
*dma_drain_needed
,
935 void *buf
, unsigned int size
);
936 extern void blk_queue_lld_busy(struct request_queue
*q
, lld_busy_fn
*fn
);
937 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
938 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
939 extern void blk_queue_unprep_rq(struct request_queue
*, unprep_rq_fn
*ufn
);
940 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
941 extern void blk_queue_dma_alignment(struct request_queue
*, int);
942 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
943 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
944 extern void blk_queue_rq_timed_out(struct request_queue
*, rq_timed_out_fn
*);
945 extern void blk_queue_rq_timeout(struct request_queue
*, unsigned int);
946 extern void blk_queue_flush(struct request_queue
*q
, unsigned int flush
);
947 extern void blk_queue_flush_queueable(struct request_queue
*q
, bool queueable
);
948 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
950 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
951 extern int blk_bio_map_sg(struct request_queue
*q
, struct bio
*bio
,
952 struct scatterlist
*sglist
);
953 extern void blk_dump_rq_flags(struct request
*, char *);
954 extern long nr_blockdev_pages(void);
956 bool __must_check
blk_get_queue(struct request_queue
*);
957 struct request_queue
*blk_alloc_queue(gfp_t
);
958 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
959 extern void blk_put_queue(struct request_queue
*);
962 * blk_plug permits building a queue of related requests by holding the I/O
963 * fragments for a short period. This allows merging of sequential requests
964 * into single larger request. As the requests are moved from a per-task list to
965 * the device's request_queue in a batch, this results in improved scalability
966 * as the lock contention for request_queue lock is reduced.
968 * It is ok not to disable preemption when adding the request to the plug list
969 * or when attempting a merge, because blk_schedule_flush_list() will only flush
970 * the plug list when the task sleeps by itself. For details, please see
971 * schedule() where blk_schedule_flush_plug() is called.
974 unsigned long magic
; /* detect uninitialized use-cases */
975 struct list_head list
; /* requests */
976 struct list_head cb_list
; /* md requires an unplug callback */
977 unsigned int should_sort
; /* list to be sorted before flushing? */
979 #define BLK_MAX_REQUEST_COUNT 16
982 typedef void (*blk_plug_cb_fn
)(struct blk_plug_cb
*, bool);
984 struct list_head list
;
985 blk_plug_cb_fn callback
;
988 extern struct blk_plug_cb
*blk_check_plugged(blk_plug_cb_fn unplug
,
989 void *data
, int size
);
990 extern void blk_start_plug(struct blk_plug
*);
991 extern void blk_finish_plug(struct blk_plug
*);
992 extern void blk_flush_plug_list(struct blk_plug
*, bool);
994 static inline void blk_flush_plug(struct task_struct
*tsk
)
996 struct blk_plug
*plug
= tsk
->plug
;
999 blk_flush_plug_list(plug
, false);
1002 static inline void blk_schedule_flush_plug(struct task_struct
*tsk
)
1004 struct blk_plug
*plug
= tsk
->plug
;
1007 blk_flush_plug_list(plug
, true);
1010 static inline bool blk_needs_flush_plug(struct task_struct
*tsk
)
1012 struct blk_plug
*plug
= tsk
->plug
;
1014 return plug
&& (!list_empty(&plug
->list
) || !list_empty(&plug
->cb_list
));
1020 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
1021 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
1022 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
1023 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
1024 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
1025 extern void blk_queue_free_tags(struct request_queue
*);
1026 extern int blk_queue_resize_tags(struct request_queue
*, int);
1027 extern void blk_queue_invalidate_tags(struct request_queue
*);
1028 extern struct blk_queue_tag
*blk_init_tags(int);
1029 extern void blk_free_tags(struct blk_queue_tag
*);
1031 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
1034 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
1036 return bqt
->tag_index
[tag
];
1039 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1041 extern int blkdev_issue_flush(struct block_device
*, gfp_t
, sector_t
*);
1042 extern int blkdev_issue_discard(struct block_device
*bdev
, sector_t sector
,
1043 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
);
1044 extern int blkdev_issue_write_same(struct block_device
*bdev
, sector_t sector
,
1045 sector_t nr_sects
, gfp_t gfp_mask
, struct page
*page
);
1046 extern int blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
1047 sector_t nr_sects
, gfp_t gfp_mask
);
1048 static inline int sb_issue_discard(struct super_block
*sb
, sector_t block
,
1049 sector_t nr_blocks
, gfp_t gfp_mask
, unsigned long flags
)
1051 return blkdev_issue_discard(sb
->s_bdev
, block
<< (sb
->s_blocksize_bits
- 9),
1052 nr_blocks
<< (sb
->s_blocksize_bits
- 9),
1055 static inline int sb_issue_zeroout(struct super_block
*sb
, sector_t block
,
1056 sector_t nr_blocks
, gfp_t gfp_mask
)
1058 return blkdev_issue_zeroout(sb
->s_bdev
,
1059 block
<< (sb
->s_blocksize_bits
- 9),
1060 nr_blocks
<< (sb
->s_blocksize_bits
- 9),
1064 extern int blk_verify_command(unsigned char *cmd
, fmode_t has_write_perm
);
1066 enum blk_default_limits
{
1067 BLK_MAX_SEGMENTS
= 128,
1068 BLK_SAFE_MAX_SECTORS
= 255,
1069 BLK_DEF_MAX_SECTORS
= 1024,
1070 BLK_MAX_SEGMENT_SIZE
= 65536,
1071 BLK_SEG_BOUNDARY_MASK
= 0xFFFFFFFFUL
,
1074 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1076 static inline unsigned long queue_bounce_pfn(struct request_queue
*q
)
1078 return q
->limits
.bounce_pfn
;
1081 static inline unsigned long queue_segment_boundary(struct request_queue
*q
)
1083 return q
->limits
.seg_boundary_mask
;
1086 static inline unsigned int queue_max_sectors(struct request_queue
*q
)
1088 return q
->limits
.max_sectors
;
1091 static inline unsigned int queue_max_hw_sectors(struct request_queue
*q
)
1093 return q
->limits
.max_hw_sectors
;
1096 static inline unsigned short queue_max_segments(struct request_queue
*q
)
1098 return q
->limits
.max_segments
;
1101 static inline unsigned int queue_max_segment_size(struct request_queue
*q
)
1103 return q
->limits
.max_segment_size
;
1106 static inline unsigned short queue_logical_block_size(struct request_queue
*q
)
1110 if (q
&& q
->limits
.logical_block_size
)
1111 retval
= q
->limits
.logical_block_size
;
1116 static inline unsigned short bdev_logical_block_size(struct block_device
*bdev
)
1118 return queue_logical_block_size(bdev_get_queue(bdev
));
1121 static inline unsigned int queue_physical_block_size(struct request_queue
*q
)
1123 return q
->limits
.physical_block_size
;
1126 static inline unsigned int bdev_physical_block_size(struct block_device
*bdev
)
1128 return queue_physical_block_size(bdev_get_queue(bdev
));
1131 static inline unsigned int queue_io_min(struct request_queue
*q
)
1133 return q
->limits
.io_min
;
1136 static inline int bdev_io_min(struct block_device
*bdev
)
1138 return queue_io_min(bdev_get_queue(bdev
));
1141 static inline unsigned int queue_io_opt(struct request_queue
*q
)
1143 return q
->limits
.io_opt
;
1146 static inline int bdev_io_opt(struct block_device
*bdev
)
1148 return queue_io_opt(bdev_get_queue(bdev
));
1151 static inline int queue_alignment_offset(struct request_queue
*q
)
1153 if (q
->limits
.misaligned
)
1156 return q
->limits
.alignment_offset
;
1159 static inline int queue_limit_alignment_offset(struct queue_limits
*lim
, sector_t sector
)
1161 unsigned int granularity
= max(lim
->physical_block_size
, lim
->io_min
);
1162 unsigned int alignment
= (sector
<< 9) & (granularity
- 1);
1164 return (granularity
+ lim
->alignment_offset
- alignment
)
1165 & (granularity
- 1);
1168 static inline int bdev_alignment_offset(struct block_device
*bdev
)
1170 struct request_queue
*q
= bdev_get_queue(bdev
);
1172 if (q
->limits
.misaligned
)
1175 if (bdev
!= bdev
->bd_contains
)
1176 return bdev
->bd_part
->alignment_offset
;
1178 return q
->limits
.alignment_offset
;
1181 static inline int queue_discard_alignment(struct request_queue
*q
)
1183 if (q
->limits
.discard_misaligned
)
1186 return q
->limits
.discard_alignment
;
1189 static inline int queue_limit_discard_alignment(struct queue_limits
*lim
, sector_t sector
)
1191 unsigned int alignment
, granularity
, offset
;
1193 if (!lim
->max_discard_sectors
)
1196 /* Why are these in bytes, not sectors? */
1197 alignment
= lim
->discard_alignment
>> 9;
1198 granularity
= lim
->discard_granularity
>> 9;
1202 /* Offset of the partition start in 'granularity' sectors */
1203 offset
= sector_div(sector
, granularity
);
1205 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1206 offset
= (granularity
+ alignment
- offset
) % granularity
;
1208 /* Turn it back into bytes, gaah */
1212 static inline int bdev_discard_alignment(struct block_device
*bdev
)
1214 struct request_queue
*q
= bdev_get_queue(bdev
);
1216 if (bdev
!= bdev
->bd_contains
)
1217 return bdev
->bd_part
->discard_alignment
;
1219 return q
->limits
.discard_alignment
;
1222 static inline unsigned int queue_discard_zeroes_data(struct request_queue
*q
)
1224 if (q
->limits
.max_discard_sectors
&& q
->limits
.discard_zeroes_data
== 1)
1230 static inline unsigned int bdev_discard_zeroes_data(struct block_device
*bdev
)
1232 return queue_discard_zeroes_data(bdev_get_queue(bdev
));
1235 static inline unsigned int bdev_write_same(struct block_device
*bdev
)
1237 struct request_queue
*q
= bdev_get_queue(bdev
);
1240 return q
->limits
.max_write_same_sectors
;
1245 static inline int queue_dma_alignment(struct request_queue
*q
)
1247 return q
? q
->dma_alignment
: 511;
1250 static inline int blk_rq_aligned(struct request_queue
*q
, unsigned long addr
,
1253 unsigned int alignment
= queue_dma_alignment(q
) | q
->dma_pad_mask
;
1254 return !(addr
& alignment
) && !(len
& alignment
);
1257 /* assumes size > 256 */
1258 static inline unsigned int blksize_bits(unsigned int size
)
1260 unsigned int bits
= 8;
1264 } while (size
> 256);
1268 static inline unsigned int block_size(struct block_device
*bdev
)
1270 return bdev
->bd_block_size
;
1273 static inline bool queue_flush_queueable(struct request_queue
*q
)
1275 return !q
->flush_not_queueable
;
1278 typedef struct {struct page
*v
;} Sector
;
1280 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
1282 static inline void put_dev_sector(Sector p
)
1284 page_cache_release(p
.v
);
1288 int kblockd_schedule_work(struct request_queue
*q
, struct work_struct
*work
);
1290 #ifdef CONFIG_BLK_CGROUP
1292 * This should not be using sched_clock(). A real patch is in progress
1293 * to fix this up, until that is in place we need to disable preemption
1294 * around sched_clock() in this function and set_io_start_time_ns().
1296 static inline void set_start_time_ns(struct request
*req
)
1299 req
->start_time_ns
= sched_clock();
1303 static inline void set_io_start_time_ns(struct request
*req
)
1306 req
->io_start_time_ns
= sched_clock();
1310 static inline uint64_t rq_start_time_ns(struct request
*req
)
1312 return req
->start_time_ns
;
1315 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1317 return req
->io_start_time_ns
;
1320 static inline void set_start_time_ns(struct request
*req
) {}
1321 static inline void set_io_start_time_ns(struct request
*req
) {}
1322 static inline uint64_t rq_start_time_ns(struct request
*req
)
1326 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1332 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1333 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1334 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1335 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1337 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1339 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1340 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1342 struct blk_integrity_exchg
{
1346 unsigned int data_size
;
1347 unsigned short sector_size
;
1348 const char *disk_name
;
1351 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
1352 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
1353 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
1354 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
1356 struct blk_integrity
{
1357 integrity_gen_fn
*generate_fn
;
1358 integrity_vrfy_fn
*verify_fn
;
1359 integrity_set_tag_fn
*set_tag_fn
;
1360 integrity_get_tag_fn
*get_tag_fn
;
1362 unsigned short flags
;
1363 unsigned short tuple_size
;
1364 unsigned short sector_size
;
1365 unsigned short tag_size
;
1369 struct kobject kobj
;
1372 extern bool blk_integrity_is_initialized(struct gendisk
*);
1373 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
1374 extern void blk_integrity_unregister(struct gendisk
*);
1375 extern int blk_integrity_compare(struct gendisk
*, struct gendisk
*);
1376 extern int blk_rq_map_integrity_sg(struct request_queue
*, struct bio
*,
1377 struct scatterlist
*);
1378 extern int blk_rq_count_integrity_sg(struct request_queue
*, struct bio
*);
1379 extern int blk_integrity_merge_rq(struct request_queue
*, struct request
*,
1381 extern int blk_integrity_merge_bio(struct request_queue
*, struct request
*,
1385 struct blk_integrity
*bdev_get_integrity(struct block_device
*bdev
)
1387 return bdev
->bd_disk
->integrity
;
1390 static inline struct blk_integrity
*blk_get_integrity(struct gendisk
*disk
)
1392 return disk
->integrity
;
1395 static inline int blk_integrity_rq(struct request
*rq
)
1397 if (rq
->bio
== NULL
)
1400 return bio_integrity(rq
->bio
);
1403 static inline void blk_queue_max_integrity_segments(struct request_queue
*q
,
1406 q
->limits
.max_integrity_segments
= segs
;
1409 static inline unsigned short
1410 queue_max_integrity_segments(struct request_queue
*q
)
1412 return q
->limits
.max_integrity_segments
;
1415 #else /* CONFIG_BLK_DEV_INTEGRITY */
1418 struct block_device
;
1420 struct blk_integrity
;
1422 static inline int blk_integrity_rq(struct request
*rq
)
1426 static inline int blk_rq_count_integrity_sg(struct request_queue
*q
,
1431 static inline int blk_rq_map_integrity_sg(struct request_queue
*q
,
1433 struct scatterlist
*s
)
1437 static inline struct blk_integrity
*bdev_get_integrity(struct block_device
*b
)
1441 static inline struct blk_integrity
*blk_get_integrity(struct gendisk
*disk
)
1445 static inline int blk_integrity_compare(struct gendisk
*a
, struct gendisk
*b
)
1449 static inline int blk_integrity_register(struct gendisk
*d
,
1450 struct blk_integrity
*b
)
1454 static inline void blk_integrity_unregister(struct gendisk
*d
)
1457 static inline void blk_queue_max_integrity_segments(struct request_queue
*q
,
1461 static inline unsigned short queue_max_integrity_segments(struct request_queue
*q
)
1465 static inline int blk_integrity_merge_rq(struct request_queue
*rq
,
1471 static inline int blk_integrity_merge_bio(struct request_queue
*rq
,
1477 static inline bool blk_integrity_is_initialized(struct gendisk
*g
)
1482 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1484 struct block_device_operations
{
1485 int (*open
) (struct block_device
*, fmode_t
);
1486 int (*release
) (struct gendisk
*, fmode_t
);
1487 int (*ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1488 int (*compat_ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1489 int (*direct_access
) (struct block_device
*, sector_t
,
1490 void **, unsigned long *);
1491 unsigned int (*check_events
) (struct gendisk
*disk
,
1492 unsigned int clearing
);
1493 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1494 int (*media_changed
) (struct gendisk
*);
1495 void (*unlock_native_capacity
) (struct gendisk
*);
1496 int (*revalidate_disk
) (struct gendisk
*);
1497 int (*getgeo
)(struct block_device
*, struct hd_geometry
*);
1498 /* this callback is with swap_lock and sometimes page table lock held */
1499 void (*swap_slot_free_notify
) (struct block_device
*, unsigned long);
1500 struct module
*owner
;
1503 extern int __blkdev_driver_ioctl(struct block_device
*, fmode_t
, unsigned int,
1505 #else /* CONFIG_BLOCK */
1507 * stubs for when the block layer is configured out
1509 #define buffer_heads_over_limit 0
1511 static inline long nr_blockdev_pages(void)
1519 static inline void blk_start_plug(struct blk_plug
*plug
)
1523 static inline void blk_finish_plug(struct blk_plug
*plug
)
1527 static inline void blk_flush_plug(struct task_struct
*task
)
1531 static inline void blk_schedule_flush_plug(struct task_struct
*task
)
1536 static inline bool blk_needs_flush_plug(struct task_struct
*tsk
)
1541 #endif /* CONFIG_BLOCK */