1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
6 #include <linux/sched.h>
7 #include <linux/major.h>
8 #include <linux/genhd.h>
9 #include <linux/list.h>
10 #include <linux/timer.h>
11 #include <linux/workqueue.h>
12 #include <linux/pagemap.h>
13 #include <linux/backing-dev.h>
14 #include <linux/wait.h>
15 #include <linux/mempool.h>
16 #include <linux/bio.h>
17 #include <linux/stringify.h>
18 #include <linux/gfp.h>
19 #include <linux/bsg.h>
20 #include <linux/smp.h>
22 #include <asm/scatterlist.h>
25 struct scsi_ioctl_command
;
28 struct elevator_queue
;
29 struct request_pm_state
;
36 #define BLKDEV_MIN_RQ 4
37 #define BLKDEV_MAX_RQ 128 /* Default maximum */
40 * Maximum number of blkcg policies allowed to be registered concurrently.
41 * Defined here to simplify include dependency.
43 #define BLKCG_MAX_POLS 2
46 typedef void (rq_end_io_fn
)(struct request
*, int);
50 * count[], starved[], and wait[] are indexed by
51 * BLK_RW_SYNC/BLK_RW_ASYNC
57 wait_queue_head_t wait
[2];
61 * request command types
63 enum rq_cmd_type_bits
{
64 REQ_TYPE_FS
= 1, /* fs request */
65 REQ_TYPE_BLOCK_PC
, /* scsi command */
66 REQ_TYPE_SENSE
, /* sense request */
67 REQ_TYPE_PM_SUSPEND
, /* suspend request */
68 REQ_TYPE_PM_RESUME
, /* resume request */
69 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
70 REQ_TYPE_SPECIAL
, /* driver defined type */
72 * for ATA/ATAPI devices. this really doesn't belong here, ide should
73 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
74 * private REQ_LB opcodes to differentiate what type of request this is
76 REQ_TYPE_ATA_TASKFILE
,
80 #define BLK_MAX_CDB 16
83 * try to put the fields that are referenced together in the same cacheline.
84 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
88 struct list_head queuelist
;
89 struct call_single_data csd
;
91 struct request_queue
*q
;
93 unsigned int cmd_flags
;
94 enum rq_cmd_type_bits cmd_type
;
95 unsigned long atomic_flags
;
99 /* the following two fields are internal, NEVER access directly */
100 unsigned int __data_len
; /* total data len */
101 sector_t __sector
; /* sector cursor */
106 struct hlist_node hash
; /* merge hash */
108 * The rb_node is only used inside the io scheduler, requests
109 * are pruned when moved to the dispatch queue. So let the
110 * completion_data share space with the rb_node.
113 struct rb_node rb_node
; /* sort/lookup */
114 void *completion_data
;
118 * Three pointers are available for the IO schedulers, if they need
119 * more they have to dynamically allocate it. Flush requests are
120 * never put on the IO scheduler. So let the flush fields share
121 * space with the elevator data.
131 struct list_head list
;
132 rq_end_io_fn
*saved_end_io
;
136 struct gendisk
*rq_disk
;
137 struct hd_struct
*part
;
138 unsigned long start_time
;
139 #ifdef CONFIG_BLK_CGROUP
140 unsigned long long start_time_ns
;
141 unsigned long long io_start_time_ns
; /* when passed to hardware */
143 /* Number of scatter-gather DMA addr+len pairs after
144 * physical address coalescing is performed.
146 unsigned short nr_phys_segments
;
147 #if defined(CONFIG_BLK_DEV_INTEGRITY)
148 unsigned short nr_integrity_segments
;
151 unsigned short ioprio
;
155 void *special
; /* opaque pointer available for LLD use */
156 char *buffer
; /* kaddr of the current segment if available */
162 * when request is used as a packet command carrier
164 unsigned char __cmd
[BLK_MAX_CDB
];
166 unsigned short cmd_len
;
168 unsigned int extra_len
; /* length of alignment and padding */
169 unsigned int sense_len
;
170 unsigned int resid_len
; /* residual count */
173 unsigned long deadline
;
174 struct list_head timeout_list
;
175 unsigned int timeout
;
179 * completion callback.
181 rq_end_io_fn
*end_io
;
185 struct request
*next_rq
;
188 static inline unsigned short req_get_ioprio(struct request
*req
)
194 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
195 * requests. Some step values could eventually be made generic.
197 struct request_pm_state
199 /* PM state machine step value, currently driver specific */
201 /* requested PM state value (S1, S2, S3, S4, ...) */
203 void* data
; /* for driver use */
206 #include <linux/elevator.h>
208 typedef void (request_fn_proc
) (struct request_queue
*q
);
209 typedef void (make_request_fn
) (struct request_queue
*q
, struct bio
*bio
);
210 typedef int (prep_rq_fn
) (struct request_queue
*, struct request
*);
211 typedef void (unprep_rq_fn
) (struct request_queue
*, struct request
*);
214 struct bvec_merge_data
{
215 struct block_device
*bi_bdev
;
220 typedef int (merge_bvec_fn
) (struct request_queue
*, struct bvec_merge_data
*,
222 typedef void (softirq_done_fn
)(struct request
*);
223 typedef int (dma_drain_needed_fn
)(struct request
*);
224 typedef int (lld_busy_fn
) (struct request_queue
*q
);
225 typedef int (bsg_job_fn
) (struct bsg_job
*);
227 enum blk_eh_timer_return
{
233 typedef enum blk_eh_timer_return (rq_timed_out_fn
)(struct request
*);
235 enum blk_queue_state
{
240 struct blk_queue_tag
{
241 struct request
**tag_index
; /* map of busy tags */
242 unsigned long *tag_map
; /* bit map of free/busy tags */
243 int busy
; /* current depth */
244 int max_depth
; /* what we will send to device */
245 int real_max_depth
; /* what the array can hold */
246 atomic_t refcnt
; /* map can be shared */
249 #define BLK_SCSI_MAX_CMDS (256)
250 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
252 struct queue_limits
{
253 unsigned long bounce_pfn
;
254 unsigned long seg_boundary_mask
;
256 unsigned int max_hw_sectors
;
257 unsigned int max_sectors
;
258 unsigned int max_segment_size
;
259 unsigned int physical_block_size
;
260 unsigned int alignment_offset
;
263 unsigned int max_discard_sectors
;
264 unsigned int discard_granularity
;
265 unsigned int discard_alignment
;
267 unsigned short logical_block_size
;
268 unsigned short max_segments
;
269 unsigned short max_integrity_segments
;
271 unsigned char misaligned
;
272 unsigned char discard_misaligned
;
273 unsigned char cluster
;
274 unsigned char discard_zeroes_data
;
277 struct request_queue
{
279 * Together with queue_head for cacheline sharing
281 struct list_head queue_head
;
282 struct request
*last_merge
;
283 struct elevator_queue
*elevator
;
286 * the queue request freelist, one for reads and one for writes
288 struct request_list rq
;
290 request_fn_proc
*request_fn
;
291 make_request_fn
*make_request_fn
;
292 prep_rq_fn
*prep_rq_fn
;
293 unprep_rq_fn
*unprep_rq_fn
;
294 merge_bvec_fn
*merge_bvec_fn
;
295 softirq_done_fn
*softirq_done_fn
;
296 rq_timed_out_fn
*rq_timed_out_fn
;
297 dma_drain_needed_fn
*dma_drain_needed
;
298 lld_busy_fn
*lld_busy_fn
;
301 * Dispatch queue sorting
304 struct request
*boundary_rq
;
307 * Delayed queue handling
309 struct delayed_work delay_work
;
311 struct backing_dev_info backing_dev_info
;
314 * The queue owner gets to use this for whatever they like.
315 * ll_rw_blk doesn't touch it.
320 * various queue flags, see QUEUE_* below
322 unsigned long queue_flags
;
325 * ida allocated id for this queue. Used to index queues from
331 * queue needs bounce pages for pages above this limit
336 * protects queue structures from reentrancy. ->__queue_lock should
337 * _never_ be used directly, it is queue private. always use
340 spinlock_t __queue_lock
;
341 spinlock_t
*queue_lock
;
351 unsigned long nr_requests
; /* Max # of requests */
352 unsigned int nr_congestion_on
;
353 unsigned int nr_congestion_off
;
354 unsigned int nr_batching
;
356 unsigned int dma_drain_size
;
357 void *dma_drain_buffer
;
358 unsigned int dma_pad_mask
;
359 unsigned int dma_alignment
;
361 struct blk_queue_tag
*queue_tags
;
362 struct list_head tag_busy_list
;
364 unsigned int nr_sorted
;
365 unsigned int in_flight
[2];
367 unsigned int rq_timeout
;
368 struct timer_list timeout
;
369 struct list_head timeout_list
;
371 struct list_head icq_list
;
372 #ifdef CONFIG_BLK_CGROUP
373 DECLARE_BITMAP (blkcg_pols
, BLKCG_MAX_POLS
);
374 struct blkio_group
*root_blkg
;
375 struct list_head blkg_list
;
378 struct queue_limits limits
;
383 unsigned int sg_timeout
;
384 unsigned int sg_reserved_size
;
386 #ifdef CONFIG_BLK_DEV_IO_TRACE
387 struct blk_trace
*blk_trace
;
390 * for flush operations
392 unsigned int flush_flags
;
393 unsigned int flush_not_queueable
:1;
394 unsigned int flush_queue_delayed
:1;
395 unsigned int flush_pending_idx
:1;
396 unsigned int flush_running_idx
:1;
397 unsigned long flush_pending_since
;
398 struct list_head flush_queue
[2];
399 struct list_head flush_data_in_flight
;
400 struct request flush_rq
;
402 struct mutex sysfs_lock
;
406 #if defined(CONFIG_BLK_DEV_BSG)
407 bsg_job_fn
*bsg_job_fn
;
409 struct bsg_class_device bsg_dev
;
412 #ifdef CONFIG_BLK_CGROUP
413 struct list_head all_q_node
;
415 #ifdef CONFIG_BLK_DEV_THROTTLING
417 struct throtl_data
*td
;
421 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
422 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
423 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
424 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
425 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
426 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
427 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
428 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
429 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
430 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
431 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
432 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
433 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
434 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
435 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
436 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
437 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
438 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
439 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
441 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
442 (1 << QUEUE_FLAG_STACKABLE) | \
443 (1 << QUEUE_FLAG_SAME_COMP) | \
444 (1 << QUEUE_FLAG_ADD_RANDOM))
446 static inline int queue_is_locked(struct request_queue
*q
)
449 spinlock_t
*lock
= q
->queue_lock
;
450 return lock
&& spin_is_locked(lock
);
456 static inline void queue_flag_set_unlocked(unsigned int flag
,
457 struct request_queue
*q
)
459 __set_bit(flag
, &q
->queue_flags
);
462 static inline int queue_flag_test_and_clear(unsigned int flag
,
463 struct request_queue
*q
)
465 WARN_ON_ONCE(!queue_is_locked(q
));
467 if (test_bit(flag
, &q
->queue_flags
)) {
468 __clear_bit(flag
, &q
->queue_flags
);
475 static inline int queue_flag_test_and_set(unsigned int flag
,
476 struct request_queue
*q
)
478 WARN_ON_ONCE(!queue_is_locked(q
));
480 if (!test_bit(flag
, &q
->queue_flags
)) {
481 __set_bit(flag
, &q
->queue_flags
);
488 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
490 WARN_ON_ONCE(!queue_is_locked(q
));
491 __set_bit(flag
, &q
->queue_flags
);
494 static inline void queue_flag_clear_unlocked(unsigned int flag
,
495 struct request_queue
*q
)
497 __clear_bit(flag
, &q
->queue_flags
);
500 static inline int queue_in_flight(struct request_queue
*q
)
502 return q
->in_flight
[0] + q
->in_flight
[1];
505 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
507 WARN_ON_ONCE(!queue_is_locked(q
));
508 __clear_bit(flag
, &q
->queue_flags
);
511 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
512 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
513 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
514 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
515 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
516 #define blk_queue_noxmerges(q) \
517 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
518 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
519 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
520 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
521 #define blk_queue_stackable(q) \
522 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
523 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
524 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
525 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
527 #define blk_noretry_request(rq) \
528 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
529 REQ_FAILFAST_DRIVER))
531 #define blk_account_rq(rq) \
532 (((rq)->cmd_flags & REQ_STARTED) && \
533 ((rq)->cmd_type == REQ_TYPE_FS || \
534 ((rq)->cmd_flags & REQ_DISCARD)))
536 #define blk_pm_request(rq) \
537 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
538 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
540 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
541 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
542 /* rq->queuelist of dequeued request must be list_empty() */
543 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
545 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
547 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
549 static inline unsigned int blk_queue_cluster(struct request_queue
*q
)
551 return q
->limits
.cluster
;
555 * We regard a request as sync, if either a read or a sync write
557 static inline bool rw_is_sync(unsigned int rw_flags
)
559 return !(rw_flags
& REQ_WRITE
) || (rw_flags
& REQ_SYNC
);
562 static inline bool rq_is_sync(struct request
*rq
)
564 return rw_is_sync(rq
->cmd_flags
);
567 static inline int blk_queue_full(struct request_queue
*q
, int sync
)
570 return test_bit(QUEUE_FLAG_SYNCFULL
, &q
->queue_flags
);
571 return test_bit(QUEUE_FLAG_ASYNCFULL
, &q
->queue_flags
);
574 static inline void blk_set_queue_full(struct request_queue
*q
, int sync
)
577 queue_flag_set(QUEUE_FLAG_SYNCFULL
, q
);
579 queue_flag_set(QUEUE_FLAG_ASYNCFULL
, q
);
582 static inline void blk_clear_queue_full(struct request_queue
*q
, int sync
)
585 queue_flag_clear(QUEUE_FLAG_SYNCFULL
, q
);
587 queue_flag_clear(QUEUE_FLAG_ASYNCFULL
, q
);
592 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
593 * it already be started by driver.
595 #define RQ_NOMERGE_FLAGS \
596 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
597 #define rq_mergeable(rq) \
598 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
599 (((rq)->cmd_flags & REQ_DISCARD) || \
600 (rq)->cmd_type == REQ_TYPE_FS))
603 * q->prep_rq_fn return values
605 #define BLKPREP_OK 0 /* serve it */
606 #define BLKPREP_KILL 1 /* fatal error, kill */
607 #define BLKPREP_DEFER 2 /* leave on queue */
609 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
612 * standard bounce addresses:
614 * BLK_BOUNCE_HIGH : bounce all highmem pages
615 * BLK_BOUNCE_ANY : don't bounce anything
616 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
619 #if BITS_PER_LONG == 32
620 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
622 #define BLK_BOUNCE_HIGH -1ULL
624 #define BLK_BOUNCE_ANY (-1ULL)
625 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
628 * default timeout for SG_IO if none specified
630 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
631 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
634 extern int init_emergency_isa_pool(void);
635 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
637 static inline int init_emergency_isa_pool(void)
641 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
644 #endif /* CONFIG_MMU */
650 unsigned long offset
;
655 struct req_iterator
{
660 /* This should not be used directly - use rq_for_each_segment */
661 #define for_each_bio(_bio) \
662 for (; _bio; _bio = _bio->bi_next)
663 #define __rq_for_each_bio(_bio, rq) \
665 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
667 #define rq_for_each_segment(bvl, _rq, _iter) \
668 __rq_for_each_bio(_iter.bio, _rq) \
669 bio_for_each_segment(bvl, _iter.bio, _iter.i)
671 #define rq_iter_last(rq, _iter) \
672 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
674 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
675 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
677 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
678 extern void rq_flush_dcache_pages(struct request
*rq
);
680 static inline void rq_flush_dcache_pages(struct request
*rq
)
685 extern int blk_register_queue(struct gendisk
*disk
);
686 extern void blk_unregister_queue(struct gendisk
*disk
);
687 extern void generic_make_request(struct bio
*bio
);
688 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
689 extern void blk_put_request(struct request
*);
690 extern void __blk_put_request(struct request_queue
*, struct request
*);
691 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
692 extern struct request
*blk_make_request(struct request_queue
*, struct bio
*,
694 extern void blk_requeue_request(struct request_queue
*, struct request
*);
695 extern void blk_add_request_payload(struct request
*rq
, struct page
*page
,
697 extern int blk_rq_check_limits(struct request_queue
*q
, struct request
*rq
);
698 extern int blk_lld_busy(struct request_queue
*q
);
699 extern int blk_rq_prep_clone(struct request
*rq
, struct request
*rq_src
,
700 struct bio_set
*bs
, gfp_t gfp_mask
,
701 int (*bio_ctr
)(struct bio
*, struct bio
*, void *),
703 extern void blk_rq_unprep_clone(struct request
*rq
);
704 extern int blk_insert_cloned_request(struct request_queue
*q
,
706 extern void blk_delay_queue(struct request_queue
*, unsigned long);
707 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
708 extern int scsi_verify_blk_ioctl(struct block_device
*, unsigned int);
709 extern int scsi_cmd_blk_ioctl(struct block_device
*, fmode_t
,
710 unsigned int, void __user
*);
711 extern int scsi_cmd_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
712 unsigned int, void __user
*);
713 extern int sg_scsi_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
714 struct scsi_ioctl_command __user
*);
716 extern void blk_queue_bio(struct request_queue
*q
, struct bio
*bio
);
719 * A queue has just exitted congestion. Note this in the global counter of
720 * congested queues, and wake up anyone who was waiting for requests to be
723 static inline void blk_clear_queue_congested(struct request_queue
*q
, int sync
)
725 clear_bdi_congested(&q
->backing_dev_info
, sync
);
729 * A queue has just entered congestion. Flag that in the queue's VM-visible
730 * state flags and increment the global gounter of congested queues.
732 static inline void blk_set_queue_congested(struct request_queue
*q
, int sync
)
734 set_bdi_congested(&q
->backing_dev_info
, sync
);
737 extern void blk_start_queue(struct request_queue
*q
);
738 extern void blk_stop_queue(struct request_queue
*q
);
739 extern void blk_sync_queue(struct request_queue
*q
);
740 extern void __blk_stop_queue(struct request_queue
*q
);
741 extern void __blk_run_queue(struct request_queue
*q
);
742 extern void blk_run_queue(struct request_queue
*);
743 extern void blk_run_queue_async(struct request_queue
*q
);
744 extern int blk_rq_map_user(struct request_queue
*, struct request
*,
745 struct rq_map_data
*, void __user
*, unsigned long,
747 extern int blk_rq_unmap_user(struct bio
*);
748 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
749 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
750 struct rq_map_data
*, struct sg_iovec
*, int,
751 unsigned int, gfp_t
);
752 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
753 struct request
*, int);
754 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
755 struct request
*, int, rq_end_io_fn
*);
757 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
759 return bdev
->bd_disk
->queue
;
763 * blk_rq_pos() : the current sector
764 * blk_rq_bytes() : bytes left in the entire request
765 * blk_rq_cur_bytes() : bytes left in the current segment
766 * blk_rq_err_bytes() : bytes left till the next error boundary
767 * blk_rq_sectors() : sectors left in the entire request
768 * blk_rq_cur_sectors() : sectors left in the current segment
770 static inline sector_t
blk_rq_pos(const struct request
*rq
)
775 static inline unsigned int blk_rq_bytes(const struct request
*rq
)
777 return rq
->__data_len
;
780 static inline int blk_rq_cur_bytes(const struct request
*rq
)
782 return rq
->bio
? bio_cur_bytes(rq
->bio
) : 0;
785 extern unsigned int blk_rq_err_bytes(const struct request
*rq
);
787 static inline unsigned int blk_rq_sectors(const struct request
*rq
)
789 return blk_rq_bytes(rq
) >> 9;
792 static inline unsigned int blk_rq_cur_sectors(const struct request
*rq
)
794 return blk_rq_cur_bytes(rq
) >> 9;
798 * Request issue related functions.
800 extern struct request
*blk_peek_request(struct request_queue
*q
);
801 extern void blk_start_request(struct request
*rq
);
802 extern struct request
*blk_fetch_request(struct request_queue
*q
);
805 * Request completion related functions.
807 * blk_update_request() completes given number of bytes and updates
808 * the request without completing it.
810 * blk_end_request() and friends. __blk_end_request() must be called
811 * with the request queue spinlock acquired.
813 * Several drivers define their own end_request and call
814 * blk_end_request() for parts of the original function.
815 * This prevents code duplication in drivers.
817 extern bool blk_update_request(struct request
*rq
, int error
,
818 unsigned int nr_bytes
);
819 extern bool blk_end_request(struct request
*rq
, int error
,
820 unsigned int nr_bytes
);
821 extern void blk_end_request_all(struct request
*rq
, int error
);
822 extern bool blk_end_request_cur(struct request
*rq
, int error
);
823 extern bool blk_end_request_err(struct request
*rq
, int error
);
824 extern bool __blk_end_request(struct request
*rq
, int error
,
825 unsigned int nr_bytes
);
826 extern void __blk_end_request_all(struct request
*rq
, int error
);
827 extern bool __blk_end_request_cur(struct request
*rq
, int error
);
828 extern bool __blk_end_request_err(struct request
*rq
, int error
);
830 extern void blk_complete_request(struct request
*);
831 extern void __blk_complete_request(struct request
*);
832 extern void blk_abort_request(struct request
*);
833 extern void blk_abort_queue(struct request_queue
*);
834 extern void blk_unprep_request(struct request
*);
837 * Access functions for manipulating queue properties
839 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
840 spinlock_t
*lock
, int node_id
);
841 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
842 extern struct request_queue
*blk_init_allocated_queue(struct request_queue
*,
843 request_fn_proc
*, spinlock_t
*);
844 extern void blk_cleanup_queue(struct request_queue
*);
845 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
846 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
847 extern void blk_limits_max_hw_sectors(struct queue_limits
*, unsigned int);
848 extern void blk_queue_max_hw_sectors(struct request_queue
*, unsigned int);
849 extern void blk_queue_max_segments(struct request_queue
*, unsigned short);
850 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
851 extern void blk_queue_max_discard_sectors(struct request_queue
*q
,
852 unsigned int max_discard_sectors
);
853 extern void blk_queue_logical_block_size(struct request_queue
*, unsigned short);
854 extern void blk_queue_physical_block_size(struct request_queue
*, unsigned int);
855 extern void blk_queue_alignment_offset(struct request_queue
*q
,
856 unsigned int alignment
);
857 extern void blk_limits_io_min(struct queue_limits
*limits
, unsigned int min
);
858 extern void blk_queue_io_min(struct request_queue
*q
, unsigned int min
);
859 extern void blk_limits_io_opt(struct queue_limits
*limits
, unsigned int opt
);
860 extern void blk_queue_io_opt(struct request_queue
*q
, unsigned int opt
);
861 extern void blk_set_default_limits(struct queue_limits
*lim
);
862 extern void blk_set_stacking_limits(struct queue_limits
*lim
);
863 extern int blk_stack_limits(struct queue_limits
*t
, struct queue_limits
*b
,
865 extern int bdev_stack_limits(struct queue_limits
*t
, struct block_device
*bdev
,
867 extern void disk_stack_limits(struct gendisk
*disk
, struct block_device
*bdev
,
869 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
870 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
871 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
872 extern int blk_queue_dma_drain(struct request_queue
*q
,
873 dma_drain_needed_fn
*dma_drain_needed
,
874 void *buf
, unsigned int size
);
875 extern void blk_queue_lld_busy(struct request_queue
*q
, lld_busy_fn
*fn
);
876 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
877 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
878 extern void blk_queue_unprep_rq(struct request_queue
*, unprep_rq_fn
*ufn
);
879 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
880 extern void blk_queue_dma_alignment(struct request_queue
*, int);
881 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
882 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
883 extern void blk_queue_rq_timed_out(struct request_queue
*, rq_timed_out_fn
*);
884 extern void blk_queue_rq_timeout(struct request_queue
*, unsigned int);
885 extern void blk_queue_flush(struct request_queue
*q
, unsigned int flush
);
886 extern void blk_queue_flush_queueable(struct request_queue
*q
, bool queueable
);
887 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
889 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
890 extern void blk_dump_rq_flags(struct request
*, char *);
891 extern long nr_blockdev_pages(void);
893 bool __must_check
blk_get_queue(struct request_queue
*);
894 struct request_queue
*blk_alloc_queue(gfp_t
);
895 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
896 extern void blk_put_queue(struct request_queue
*);
899 * blk_plug permits building a queue of related requests by holding the I/O
900 * fragments for a short period. This allows merging of sequential requests
901 * into single larger request. As the requests are moved from a per-task list to
902 * the device's request_queue in a batch, this results in improved scalability
903 * as the lock contention for request_queue lock is reduced.
905 * It is ok not to disable preemption when adding the request to the plug list
906 * or when attempting a merge, because blk_schedule_flush_list() will only flush
907 * the plug list when the task sleeps by itself. For details, please see
908 * schedule() where blk_schedule_flush_plug() is called.
911 unsigned long magic
; /* detect uninitialized use-cases */
912 struct list_head list
; /* requests */
913 struct list_head cb_list
; /* md requires an unplug callback */
914 unsigned int should_sort
; /* list to be sorted before flushing? */
916 #define BLK_MAX_REQUEST_COUNT 16
919 struct list_head list
;
920 void (*callback
)(struct blk_plug_cb
*);
923 extern void blk_start_plug(struct blk_plug
*);
924 extern void blk_finish_plug(struct blk_plug
*);
925 extern void blk_flush_plug_list(struct blk_plug
*, bool);
927 static inline void blk_flush_plug(struct task_struct
*tsk
)
929 struct blk_plug
*plug
= tsk
->plug
;
932 blk_flush_plug_list(plug
, false);
935 static inline void blk_schedule_flush_plug(struct task_struct
*tsk
)
937 struct blk_plug
*plug
= tsk
->plug
;
940 blk_flush_plug_list(plug
, true);
943 static inline bool blk_needs_flush_plug(struct task_struct
*tsk
)
945 struct blk_plug
*plug
= tsk
->plug
;
947 return plug
&& (!list_empty(&plug
->list
) || !list_empty(&plug
->cb_list
));
953 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
954 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
955 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
956 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
957 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
958 extern void blk_queue_free_tags(struct request_queue
*);
959 extern int blk_queue_resize_tags(struct request_queue
*, int);
960 extern void blk_queue_invalidate_tags(struct request_queue
*);
961 extern struct blk_queue_tag
*blk_init_tags(int);
962 extern void blk_free_tags(struct blk_queue_tag
*);
964 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
967 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
969 return bqt
->tag_index
[tag
];
972 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
974 extern int blkdev_issue_flush(struct block_device
*, gfp_t
, sector_t
*);
975 extern int blkdev_issue_discard(struct block_device
*bdev
, sector_t sector
,
976 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
);
977 extern int blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
978 sector_t nr_sects
, gfp_t gfp_mask
);
979 static inline int sb_issue_discard(struct super_block
*sb
, sector_t block
,
980 sector_t nr_blocks
, gfp_t gfp_mask
, unsigned long flags
)
982 return blkdev_issue_discard(sb
->s_bdev
, block
<< (sb
->s_blocksize_bits
- 9),
983 nr_blocks
<< (sb
->s_blocksize_bits
- 9),
986 static inline int sb_issue_zeroout(struct super_block
*sb
, sector_t block
,
987 sector_t nr_blocks
, gfp_t gfp_mask
)
989 return blkdev_issue_zeroout(sb
->s_bdev
,
990 block
<< (sb
->s_blocksize_bits
- 9),
991 nr_blocks
<< (sb
->s_blocksize_bits
- 9),
995 extern int blk_verify_command(unsigned char *cmd
, fmode_t has_write_perm
);
997 enum blk_default_limits
{
998 BLK_MAX_SEGMENTS
= 128,
999 BLK_SAFE_MAX_SECTORS
= 255,
1000 BLK_DEF_MAX_SECTORS
= 1024,
1001 BLK_MAX_SEGMENT_SIZE
= 65536,
1002 BLK_SEG_BOUNDARY_MASK
= 0xFFFFFFFFUL
,
1005 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1007 static inline unsigned long queue_bounce_pfn(struct request_queue
*q
)
1009 return q
->limits
.bounce_pfn
;
1012 static inline unsigned long queue_segment_boundary(struct request_queue
*q
)
1014 return q
->limits
.seg_boundary_mask
;
1017 static inline unsigned int queue_max_sectors(struct request_queue
*q
)
1019 return q
->limits
.max_sectors
;
1022 static inline unsigned int queue_max_hw_sectors(struct request_queue
*q
)
1024 return q
->limits
.max_hw_sectors
;
1027 static inline unsigned short queue_max_segments(struct request_queue
*q
)
1029 return q
->limits
.max_segments
;
1032 static inline unsigned int queue_max_segment_size(struct request_queue
*q
)
1034 return q
->limits
.max_segment_size
;
1037 static inline unsigned short queue_logical_block_size(struct request_queue
*q
)
1041 if (q
&& q
->limits
.logical_block_size
)
1042 retval
= q
->limits
.logical_block_size
;
1047 static inline unsigned short bdev_logical_block_size(struct block_device
*bdev
)
1049 return queue_logical_block_size(bdev_get_queue(bdev
));
1052 static inline unsigned int queue_physical_block_size(struct request_queue
*q
)
1054 return q
->limits
.physical_block_size
;
1057 static inline unsigned int bdev_physical_block_size(struct block_device
*bdev
)
1059 return queue_physical_block_size(bdev_get_queue(bdev
));
1062 static inline unsigned int queue_io_min(struct request_queue
*q
)
1064 return q
->limits
.io_min
;
1067 static inline int bdev_io_min(struct block_device
*bdev
)
1069 return queue_io_min(bdev_get_queue(bdev
));
1072 static inline unsigned int queue_io_opt(struct request_queue
*q
)
1074 return q
->limits
.io_opt
;
1077 static inline int bdev_io_opt(struct block_device
*bdev
)
1079 return queue_io_opt(bdev_get_queue(bdev
));
1082 static inline int queue_alignment_offset(struct request_queue
*q
)
1084 if (q
->limits
.misaligned
)
1087 return q
->limits
.alignment_offset
;
1090 static inline int queue_limit_alignment_offset(struct queue_limits
*lim
, sector_t sector
)
1092 unsigned int granularity
= max(lim
->physical_block_size
, lim
->io_min
);
1093 unsigned int alignment
= (sector
<< 9) & (granularity
- 1);
1095 return (granularity
+ lim
->alignment_offset
- alignment
)
1096 & (granularity
- 1);
1099 static inline int bdev_alignment_offset(struct block_device
*bdev
)
1101 struct request_queue
*q
= bdev_get_queue(bdev
);
1103 if (q
->limits
.misaligned
)
1106 if (bdev
!= bdev
->bd_contains
)
1107 return bdev
->bd_part
->alignment_offset
;
1109 return q
->limits
.alignment_offset
;
1112 static inline int queue_discard_alignment(struct request_queue
*q
)
1114 if (q
->limits
.discard_misaligned
)
1117 return q
->limits
.discard_alignment
;
1120 static inline int queue_limit_discard_alignment(struct queue_limits
*lim
, sector_t sector
)
1122 unsigned int alignment
= (sector
<< 9) & (lim
->discard_granularity
- 1);
1124 if (!lim
->max_discard_sectors
)
1127 return (lim
->discard_granularity
+ lim
->discard_alignment
- alignment
)
1128 & (lim
->discard_granularity
- 1);
1131 static inline unsigned int queue_discard_zeroes_data(struct request_queue
*q
)
1133 if (q
->limits
.max_discard_sectors
&& q
->limits
.discard_zeroes_data
== 1)
1139 static inline unsigned int bdev_discard_zeroes_data(struct block_device
*bdev
)
1141 return queue_discard_zeroes_data(bdev_get_queue(bdev
));
1144 static inline int queue_dma_alignment(struct request_queue
*q
)
1146 return q
? q
->dma_alignment
: 511;
1149 static inline int blk_rq_aligned(struct request_queue
*q
, unsigned long addr
,
1152 unsigned int alignment
= queue_dma_alignment(q
) | q
->dma_pad_mask
;
1153 return !(addr
& alignment
) && !(len
& alignment
);
1156 /* assumes size > 256 */
1157 static inline unsigned int blksize_bits(unsigned int size
)
1159 unsigned int bits
= 8;
1163 } while (size
> 256);
1167 static inline unsigned int block_size(struct block_device
*bdev
)
1169 return bdev
->bd_block_size
;
1172 static inline bool queue_flush_queueable(struct request_queue
*q
)
1174 return !q
->flush_not_queueable
;
1177 typedef struct {struct page
*v
;} Sector
;
1179 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
1181 static inline void put_dev_sector(Sector p
)
1183 page_cache_release(p
.v
);
1187 int kblockd_schedule_work(struct request_queue
*q
, struct work_struct
*work
);
1189 #ifdef CONFIG_BLK_CGROUP
1191 * This should not be using sched_clock(). A real patch is in progress
1192 * to fix this up, until that is in place we need to disable preemption
1193 * around sched_clock() in this function and set_io_start_time_ns().
1195 static inline void set_start_time_ns(struct request
*req
)
1198 req
->start_time_ns
= sched_clock();
1202 static inline void set_io_start_time_ns(struct request
*req
)
1205 req
->io_start_time_ns
= sched_clock();
1209 static inline uint64_t rq_start_time_ns(struct request
*req
)
1211 return req
->start_time_ns
;
1214 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1216 return req
->io_start_time_ns
;
1219 static inline void set_start_time_ns(struct request
*req
) {}
1220 static inline void set_io_start_time_ns(struct request
*req
) {}
1221 static inline uint64_t rq_start_time_ns(struct request
*req
)
1225 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1231 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1232 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1233 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1234 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1236 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1238 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1239 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1241 struct blk_integrity_exchg
{
1245 unsigned int data_size
;
1246 unsigned short sector_size
;
1247 const char *disk_name
;
1250 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
1251 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
1252 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
1253 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
1255 struct blk_integrity
{
1256 integrity_gen_fn
*generate_fn
;
1257 integrity_vrfy_fn
*verify_fn
;
1258 integrity_set_tag_fn
*set_tag_fn
;
1259 integrity_get_tag_fn
*get_tag_fn
;
1261 unsigned short flags
;
1262 unsigned short tuple_size
;
1263 unsigned short sector_size
;
1264 unsigned short tag_size
;
1268 struct kobject kobj
;
1271 extern bool blk_integrity_is_initialized(struct gendisk
*);
1272 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
1273 extern void blk_integrity_unregister(struct gendisk
*);
1274 extern int blk_integrity_compare(struct gendisk
*, struct gendisk
*);
1275 extern int blk_rq_map_integrity_sg(struct request_queue
*, struct bio
*,
1276 struct scatterlist
*);
1277 extern int blk_rq_count_integrity_sg(struct request_queue
*, struct bio
*);
1278 extern int blk_integrity_merge_rq(struct request_queue
*, struct request
*,
1280 extern int blk_integrity_merge_bio(struct request_queue
*, struct request
*,
1284 struct blk_integrity
*bdev_get_integrity(struct block_device
*bdev
)
1286 return bdev
->bd_disk
->integrity
;
1289 static inline struct blk_integrity
*blk_get_integrity(struct gendisk
*disk
)
1291 return disk
->integrity
;
1294 static inline int blk_integrity_rq(struct request
*rq
)
1296 if (rq
->bio
== NULL
)
1299 return bio_integrity(rq
->bio
);
1302 static inline void blk_queue_max_integrity_segments(struct request_queue
*q
,
1305 q
->limits
.max_integrity_segments
= segs
;
1308 static inline unsigned short
1309 queue_max_integrity_segments(struct request_queue
*q
)
1311 return q
->limits
.max_integrity_segments
;
1314 #else /* CONFIG_BLK_DEV_INTEGRITY */
1317 struct block_device
;
1319 struct blk_integrity
;
1321 static inline int blk_integrity_rq(struct request
*rq
)
1325 static inline int blk_rq_count_integrity_sg(struct request_queue
*q
,
1330 static inline int blk_rq_map_integrity_sg(struct request_queue
*q
,
1332 struct scatterlist
*s
)
1336 static inline struct blk_integrity
*bdev_get_integrity(struct block_device
*b
)
1340 static inline struct blk_integrity
*blk_get_integrity(struct gendisk
*disk
)
1344 static inline int blk_integrity_compare(struct gendisk
*a
, struct gendisk
*b
)
1348 static inline int blk_integrity_register(struct gendisk
*d
,
1349 struct blk_integrity
*b
)
1353 static inline void blk_integrity_unregister(struct gendisk
*d
)
1356 static inline void blk_queue_max_integrity_segments(struct request_queue
*q
,
1360 static inline unsigned short queue_max_integrity_segments(struct request_queue
*q
)
1364 static inline int blk_integrity_merge_rq(struct request_queue
*rq
,
1370 static inline int blk_integrity_merge_bio(struct request_queue
*rq
,
1376 static inline bool blk_integrity_is_initialized(struct gendisk
*g
)
1381 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1383 struct block_device_operations
{
1384 int (*open
) (struct block_device
*, fmode_t
);
1385 int (*release
) (struct gendisk
*, fmode_t
);
1386 int (*ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1387 int (*compat_ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1388 int (*direct_access
) (struct block_device
*, sector_t
,
1389 void **, unsigned long *);
1390 unsigned int (*check_events
) (struct gendisk
*disk
,
1391 unsigned int clearing
);
1392 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1393 int (*media_changed
) (struct gendisk
*);
1394 void (*unlock_native_capacity
) (struct gendisk
*);
1395 int (*revalidate_disk
) (struct gendisk
*);
1396 int (*getgeo
)(struct block_device
*, struct hd_geometry
*);
1397 /* this callback is with swap_lock and sometimes page table lock held */
1398 void (*swap_slot_free_notify
) (struct block_device
*, unsigned long);
1399 struct module
*owner
;
1402 extern int __blkdev_driver_ioctl(struct block_device
*, fmode_t
, unsigned int,
1404 #else /* CONFIG_BLOCK */
1406 * stubs for when the block layer is configured out
1408 #define buffer_heads_over_limit 0
1410 static inline long nr_blockdev_pages(void)
1418 static inline void blk_start_plug(struct blk_plug
*plug
)
1422 static inline void blk_finish_plug(struct blk_plug
*plug
)
1426 static inline void blk_flush_plug(struct task_struct
*task
)
1430 static inline void blk_schedule_flush_plug(struct task_struct
*task
)
1435 static inline bool blk_needs_flush_plug(struct task_struct
*tsk
)
1440 #endif /* CONFIG_BLOCK */