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
;
35 #define BLKDEV_MIN_RQ 4
36 #define BLKDEV_MAX_RQ 128 /* Default maximum */
39 typedef void (rq_end_io_fn
)(struct request
*, int);
43 * count[], starved[], and wait[] are indexed by
44 * BLK_RW_SYNC/BLK_RW_ASYNC
50 wait_queue_head_t wait
[2];
54 * request command types
56 enum rq_cmd_type_bits
{
57 REQ_TYPE_FS
= 1, /* fs request */
58 REQ_TYPE_BLOCK_PC
, /* scsi command */
59 REQ_TYPE_SENSE
, /* sense request */
60 REQ_TYPE_PM_SUSPEND
, /* suspend request */
61 REQ_TYPE_PM_RESUME
, /* resume request */
62 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
63 REQ_TYPE_SPECIAL
, /* driver defined type */
65 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 * private REQ_LB opcodes to differentiate what type of request this is
69 REQ_TYPE_ATA_TASKFILE
,
73 #define BLK_MAX_CDB 16
76 * try to put the fields that are referenced together in the same cacheline.
77 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
81 struct list_head queuelist
;
82 struct call_single_data csd
;
84 struct request_queue
*q
;
86 unsigned int cmd_flags
;
87 enum rq_cmd_type_bits cmd_type
;
88 unsigned long atomic_flags
;
92 /* the following two fields are internal, NEVER access directly */
93 unsigned int __data_len
; /* total data len */
94 sector_t __sector
; /* sector cursor */
99 struct hlist_node hash
; /* merge hash */
101 * The rb_node is only used inside the io scheduler, requests
102 * are pruned when moved to the dispatch queue. So let the
103 * completion_data share space with the rb_node.
106 struct rb_node rb_node
; /* sort/lookup */
107 void *completion_data
;
111 * Three pointers are available for the IO schedulers, if they need
112 * more they have to dynamically allocate it. Flush requests are
113 * never put on the IO scheduler. So let the flush fields share
114 * space with the elevator data.
124 struct list_head list
;
125 rq_end_io_fn
*saved_end_io
;
129 struct gendisk
*rq_disk
;
130 struct hd_struct
*part
;
131 unsigned long start_time
;
132 #ifdef CONFIG_BLK_CGROUP
133 unsigned long long start_time_ns
;
134 unsigned long long io_start_time_ns
; /* when passed to hardware */
136 /* Number of scatter-gather DMA addr+len pairs after
137 * physical address coalescing is performed.
139 unsigned short nr_phys_segments
;
140 #if defined(CONFIG_BLK_DEV_INTEGRITY)
141 unsigned short nr_integrity_segments
;
144 unsigned short ioprio
;
148 void *special
; /* opaque pointer available for LLD use */
149 char *buffer
; /* kaddr of the current segment if available */
155 * when request is used as a packet command carrier
157 unsigned char __cmd
[BLK_MAX_CDB
];
159 unsigned short cmd_len
;
161 unsigned int extra_len
; /* length of alignment and padding */
162 unsigned int sense_len
;
163 unsigned int resid_len
; /* residual count */
166 unsigned long deadline
;
167 struct list_head timeout_list
;
168 unsigned int timeout
;
172 * completion callback.
174 rq_end_io_fn
*end_io
;
178 struct request
*next_rq
;
181 static inline unsigned short req_get_ioprio(struct request
*req
)
187 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
188 * requests. Some step values could eventually be made generic.
190 struct request_pm_state
192 /* PM state machine step value, currently driver specific */
194 /* requested PM state value (S1, S2, S3, S4, ...) */
196 void* data
; /* for driver use */
199 #include <linux/elevator.h>
201 typedef void (request_fn_proc
) (struct request_queue
*q
);
202 typedef void (make_request_fn
) (struct request_queue
*q
, struct bio
*bio
);
203 typedef int (prep_rq_fn
) (struct request_queue
*, struct request
*);
204 typedef void (unprep_rq_fn
) (struct request_queue
*, struct request
*);
207 struct bvec_merge_data
{
208 struct block_device
*bi_bdev
;
213 typedef int (merge_bvec_fn
) (struct request_queue
*, struct bvec_merge_data
*,
215 typedef void (softirq_done_fn
)(struct request
*);
216 typedef int (dma_drain_needed_fn
)(struct request
*);
217 typedef int (lld_busy_fn
) (struct request_queue
*q
);
218 typedef int (bsg_job_fn
) (struct bsg_job
*);
220 enum blk_eh_timer_return
{
226 typedef enum blk_eh_timer_return (rq_timed_out_fn
)(struct request
*);
228 enum blk_queue_state
{
233 struct blk_queue_tag
{
234 struct request
**tag_index
; /* map of busy tags */
235 unsigned long *tag_map
; /* bit map of free/busy tags */
236 int busy
; /* current depth */
237 int max_depth
; /* what we will send to device */
238 int real_max_depth
; /* what the array can hold */
239 atomic_t refcnt
; /* map can be shared */
242 #define BLK_SCSI_MAX_CMDS (256)
243 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
245 struct queue_limits
{
246 unsigned long bounce_pfn
;
247 unsigned long seg_boundary_mask
;
249 unsigned int max_hw_sectors
;
250 unsigned int max_sectors
;
251 unsigned int max_segment_size
;
252 unsigned int physical_block_size
;
253 unsigned int alignment_offset
;
256 unsigned int max_discard_sectors
;
257 unsigned int discard_granularity
;
258 unsigned int discard_alignment
;
260 unsigned short logical_block_size
;
261 unsigned short max_segments
;
262 unsigned short max_integrity_segments
;
264 unsigned char misaligned
;
265 unsigned char discard_misaligned
;
266 unsigned char cluster
;
267 unsigned char discard_zeroes_data
;
270 struct request_queue
{
272 * Together with queue_head for cacheline sharing
274 struct list_head queue_head
;
275 struct request
*last_merge
;
276 struct elevator_queue
*elevator
;
279 * the queue request freelist, one for reads and one for writes
281 struct request_list rq
;
283 request_fn_proc
*request_fn
;
284 make_request_fn
*make_request_fn
;
285 prep_rq_fn
*prep_rq_fn
;
286 unprep_rq_fn
*unprep_rq_fn
;
287 merge_bvec_fn
*merge_bvec_fn
;
288 softirq_done_fn
*softirq_done_fn
;
289 rq_timed_out_fn
*rq_timed_out_fn
;
290 dma_drain_needed_fn
*dma_drain_needed
;
291 lld_busy_fn
*lld_busy_fn
;
294 * Dispatch queue sorting
297 struct request
*boundary_rq
;
300 * Delayed queue handling
302 struct delayed_work delay_work
;
304 struct backing_dev_info backing_dev_info
;
307 * The queue owner gets to use this for whatever they like.
308 * ll_rw_blk doesn't touch it.
313 * various queue flags, see QUEUE_* below
315 unsigned long queue_flags
;
318 * ida allocated id for this queue. Used to index queues from
324 * queue needs bounce pages for pages above this limit
329 * protects queue structures from reentrancy. ->__queue_lock should
330 * _never_ be used directly, it is queue private. always use
333 spinlock_t __queue_lock
;
334 spinlock_t
*queue_lock
;
344 unsigned long nr_requests
; /* Max # of requests */
345 unsigned int nr_congestion_on
;
346 unsigned int nr_congestion_off
;
347 unsigned int nr_batching
;
349 unsigned int dma_drain_size
;
350 void *dma_drain_buffer
;
351 unsigned int dma_pad_mask
;
352 unsigned int dma_alignment
;
354 struct blk_queue_tag
*queue_tags
;
355 struct list_head tag_busy_list
;
357 unsigned int nr_sorted
;
358 unsigned int in_flight
[2];
360 unsigned int rq_timeout
;
361 struct timer_list timeout
;
362 struct list_head timeout_list
;
364 struct list_head icq_list
;
365 #ifdef CONFIG_BLK_CGROUP
366 /* XXX: array size hardcoded to avoid include dependency (temporary) */
367 struct list_head blkg_list
;
370 struct queue_limits limits
;
375 unsigned int sg_timeout
;
376 unsigned int sg_reserved_size
;
378 #ifdef CONFIG_BLK_DEV_IO_TRACE
379 struct blk_trace
*blk_trace
;
382 * for flush operations
384 unsigned int flush_flags
;
385 unsigned int flush_not_queueable
:1;
386 unsigned int flush_queue_delayed
:1;
387 unsigned int flush_pending_idx
:1;
388 unsigned int flush_running_idx
:1;
389 unsigned long flush_pending_since
;
390 struct list_head flush_queue
[2];
391 struct list_head flush_data_in_flight
;
392 struct request flush_rq
;
394 struct mutex sysfs_lock
;
398 #if defined(CONFIG_BLK_DEV_BSG)
399 bsg_job_fn
*bsg_job_fn
;
401 struct bsg_class_device bsg_dev
;
404 #ifdef CONFIG_BLK_CGROUP
405 struct list_head all_q_node
;
407 #ifdef CONFIG_BLK_DEV_THROTTLING
409 struct throtl_data
*td
;
413 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
414 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
415 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
416 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
417 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
418 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
419 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
420 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
421 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
422 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
423 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
424 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
425 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
426 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
427 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
428 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
429 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
430 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
431 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
433 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
434 (1 << QUEUE_FLAG_STACKABLE) | \
435 (1 << QUEUE_FLAG_SAME_COMP) | \
436 (1 << QUEUE_FLAG_ADD_RANDOM))
438 static inline int queue_is_locked(struct request_queue
*q
)
441 spinlock_t
*lock
= q
->queue_lock
;
442 return lock
&& spin_is_locked(lock
);
448 static inline void queue_flag_set_unlocked(unsigned int flag
,
449 struct request_queue
*q
)
451 __set_bit(flag
, &q
->queue_flags
);
454 static inline int queue_flag_test_and_clear(unsigned int flag
,
455 struct request_queue
*q
)
457 WARN_ON_ONCE(!queue_is_locked(q
));
459 if (test_bit(flag
, &q
->queue_flags
)) {
460 __clear_bit(flag
, &q
->queue_flags
);
467 static inline int queue_flag_test_and_set(unsigned int flag
,
468 struct request_queue
*q
)
470 WARN_ON_ONCE(!queue_is_locked(q
));
472 if (!test_bit(flag
, &q
->queue_flags
)) {
473 __set_bit(flag
, &q
->queue_flags
);
480 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
482 WARN_ON_ONCE(!queue_is_locked(q
));
483 __set_bit(flag
, &q
->queue_flags
);
486 static inline void queue_flag_clear_unlocked(unsigned int flag
,
487 struct request_queue
*q
)
489 __clear_bit(flag
, &q
->queue_flags
);
492 static inline int queue_in_flight(struct request_queue
*q
)
494 return q
->in_flight
[0] + q
->in_flight
[1];
497 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
499 WARN_ON_ONCE(!queue_is_locked(q
));
500 __clear_bit(flag
, &q
->queue_flags
);
503 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
504 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
505 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
506 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
507 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
508 #define blk_queue_noxmerges(q) \
509 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
510 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
511 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
512 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
513 #define blk_queue_stackable(q) \
514 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
515 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
516 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
517 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
519 #define blk_noretry_request(rq) \
520 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
521 REQ_FAILFAST_DRIVER))
523 #define blk_account_rq(rq) \
524 (((rq)->cmd_flags & REQ_STARTED) && \
525 ((rq)->cmd_type == REQ_TYPE_FS || \
526 ((rq)->cmd_flags & REQ_DISCARD)))
528 #define blk_pm_request(rq) \
529 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
530 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
532 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
533 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
534 /* rq->queuelist of dequeued request must be list_empty() */
535 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
537 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
539 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
541 static inline unsigned int blk_queue_cluster(struct request_queue
*q
)
543 return q
->limits
.cluster
;
547 * We regard a request as sync, if either a read or a sync write
549 static inline bool rw_is_sync(unsigned int rw_flags
)
551 return !(rw_flags
& REQ_WRITE
) || (rw_flags
& REQ_SYNC
);
554 static inline bool rq_is_sync(struct request
*rq
)
556 return rw_is_sync(rq
->cmd_flags
);
559 static inline int blk_queue_full(struct request_queue
*q
, int sync
)
562 return test_bit(QUEUE_FLAG_SYNCFULL
, &q
->queue_flags
);
563 return test_bit(QUEUE_FLAG_ASYNCFULL
, &q
->queue_flags
);
566 static inline void blk_set_queue_full(struct request_queue
*q
, int sync
)
569 queue_flag_set(QUEUE_FLAG_SYNCFULL
, q
);
571 queue_flag_set(QUEUE_FLAG_ASYNCFULL
, q
);
574 static inline void blk_clear_queue_full(struct request_queue
*q
, int sync
)
577 queue_flag_clear(QUEUE_FLAG_SYNCFULL
, q
);
579 queue_flag_clear(QUEUE_FLAG_ASYNCFULL
, q
);
584 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
585 * it already be started by driver.
587 #define RQ_NOMERGE_FLAGS \
588 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
589 #define rq_mergeable(rq) \
590 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
591 (((rq)->cmd_flags & REQ_DISCARD) || \
592 (rq)->cmd_type == REQ_TYPE_FS))
595 * q->prep_rq_fn return values
597 #define BLKPREP_OK 0 /* serve it */
598 #define BLKPREP_KILL 1 /* fatal error, kill */
599 #define BLKPREP_DEFER 2 /* leave on queue */
601 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
604 * standard bounce addresses:
606 * BLK_BOUNCE_HIGH : bounce all highmem pages
607 * BLK_BOUNCE_ANY : don't bounce anything
608 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
611 #if BITS_PER_LONG == 32
612 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
614 #define BLK_BOUNCE_HIGH -1ULL
616 #define BLK_BOUNCE_ANY (-1ULL)
617 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
620 * default timeout for SG_IO if none specified
622 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
623 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
626 extern int init_emergency_isa_pool(void);
627 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
629 static inline int init_emergency_isa_pool(void)
633 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
636 #endif /* CONFIG_MMU */
642 unsigned long offset
;
647 struct req_iterator
{
652 /* This should not be used directly - use rq_for_each_segment */
653 #define for_each_bio(_bio) \
654 for (; _bio; _bio = _bio->bi_next)
655 #define __rq_for_each_bio(_bio, rq) \
657 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
659 #define rq_for_each_segment(bvl, _rq, _iter) \
660 __rq_for_each_bio(_iter.bio, _rq) \
661 bio_for_each_segment(bvl, _iter.bio, _iter.i)
663 #define rq_iter_last(rq, _iter) \
664 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
666 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
667 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
669 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
670 extern void rq_flush_dcache_pages(struct request
*rq
);
672 static inline void rq_flush_dcache_pages(struct request
*rq
)
677 extern int blk_register_queue(struct gendisk
*disk
);
678 extern void blk_unregister_queue(struct gendisk
*disk
);
679 extern void generic_make_request(struct bio
*bio
);
680 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
681 extern void blk_put_request(struct request
*);
682 extern void __blk_put_request(struct request_queue
*, struct request
*);
683 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
684 extern struct request
*blk_make_request(struct request_queue
*, struct bio
*,
686 extern void blk_requeue_request(struct request_queue
*, struct request
*);
687 extern void blk_add_request_payload(struct request
*rq
, struct page
*page
,
689 extern int blk_rq_check_limits(struct request_queue
*q
, struct request
*rq
);
690 extern int blk_lld_busy(struct request_queue
*q
);
691 extern int blk_rq_prep_clone(struct request
*rq
, struct request
*rq_src
,
692 struct bio_set
*bs
, gfp_t gfp_mask
,
693 int (*bio_ctr
)(struct bio
*, struct bio
*, void *),
695 extern void blk_rq_unprep_clone(struct request
*rq
);
696 extern int blk_insert_cloned_request(struct request_queue
*q
,
698 extern void blk_delay_queue(struct request_queue
*, unsigned long);
699 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
700 extern int scsi_verify_blk_ioctl(struct block_device
*, unsigned int);
701 extern int scsi_cmd_blk_ioctl(struct block_device
*, fmode_t
,
702 unsigned int, void __user
*);
703 extern int scsi_cmd_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
704 unsigned int, void __user
*);
705 extern int sg_scsi_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
706 struct scsi_ioctl_command __user
*);
708 extern void blk_queue_bio(struct request_queue
*q
, struct bio
*bio
);
711 * A queue has just exitted congestion. Note this in the global counter of
712 * congested queues, and wake up anyone who was waiting for requests to be
715 static inline void blk_clear_queue_congested(struct request_queue
*q
, int sync
)
717 clear_bdi_congested(&q
->backing_dev_info
, sync
);
721 * A queue has just entered congestion. Flag that in the queue's VM-visible
722 * state flags and increment the global gounter of congested queues.
724 static inline void blk_set_queue_congested(struct request_queue
*q
, int sync
)
726 set_bdi_congested(&q
->backing_dev_info
, sync
);
729 extern void blk_start_queue(struct request_queue
*q
);
730 extern void blk_stop_queue(struct request_queue
*q
);
731 extern void blk_sync_queue(struct request_queue
*q
);
732 extern void __blk_stop_queue(struct request_queue
*q
);
733 extern void __blk_run_queue(struct request_queue
*q
);
734 extern void blk_run_queue(struct request_queue
*);
735 extern void blk_run_queue_async(struct request_queue
*q
);
736 extern int blk_rq_map_user(struct request_queue
*, struct request
*,
737 struct rq_map_data
*, void __user
*, unsigned long,
739 extern int blk_rq_unmap_user(struct bio
*);
740 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
741 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
742 struct rq_map_data
*, struct sg_iovec
*, int,
743 unsigned int, gfp_t
);
744 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
745 struct request
*, int);
746 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
747 struct request
*, int, rq_end_io_fn
*);
749 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
751 return bdev
->bd_disk
->queue
;
755 * blk_rq_pos() : the current sector
756 * blk_rq_bytes() : bytes left in the entire request
757 * blk_rq_cur_bytes() : bytes left in the current segment
758 * blk_rq_err_bytes() : bytes left till the next error boundary
759 * blk_rq_sectors() : sectors left in the entire request
760 * blk_rq_cur_sectors() : sectors left in the current segment
762 static inline sector_t
blk_rq_pos(const struct request
*rq
)
767 static inline unsigned int blk_rq_bytes(const struct request
*rq
)
769 return rq
->__data_len
;
772 static inline int blk_rq_cur_bytes(const struct request
*rq
)
774 return rq
->bio
? bio_cur_bytes(rq
->bio
) : 0;
777 extern unsigned int blk_rq_err_bytes(const struct request
*rq
);
779 static inline unsigned int blk_rq_sectors(const struct request
*rq
)
781 return blk_rq_bytes(rq
) >> 9;
784 static inline unsigned int blk_rq_cur_sectors(const struct request
*rq
)
786 return blk_rq_cur_bytes(rq
) >> 9;
790 * Request issue related functions.
792 extern struct request
*blk_peek_request(struct request_queue
*q
);
793 extern void blk_start_request(struct request
*rq
);
794 extern struct request
*blk_fetch_request(struct request_queue
*q
);
797 * Request completion related functions.
799 * blk_update_request() completes given number of bytes and updates
800 * the request without completing it.
802 * blk_end_request() and friends. __blk_end_request() must be called
803 * with the request queue spinlock acquired.
805 * Several drivers define their own end_request and call
806 * blk_end_request() for parts of the original function.
807 * This prevents code duplication in drivers.
809 extern bool blk_update_request(struct request
*rq
, int error
,
810 unsigned int nr_bytes
);
811 extern bool blk_end_request(struct request
*rq
, int error
,
812 unsigned int nr_bytes
);
813 extern void blk_end_request_all(struct request
*rq
, int error
);
814 extern bool blk_end_request_cur(struct request
*rq
, int error
);
815 extern bool blk_end_request_err(struct request
*rq
, int error
);
816 extern bool __blk_end_request(struct request
*rq
, int error
,
817 unsigned int nr_bytes
);
818 extern void __blk_end_request_all(struct request
*rq
, int error
);
819 extern bool __blk_end_request_cur(struct request
*rq
, int error
);
820 extern bool __blk_end_request_err(struct request
*rq
, int error
);
822 extern void blk_complete_request(struct request
*);
823 extern void __blk_complete_request(struct request
*);
824 extern void blk_abort_request(struct request
*);
825 extern void blk_abort_queue(struct request_queue
*);
826 extern void blk_unprep_request(struct request
*);
829 * Access functions for manipulating queue properties
831 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
832 spinlock_t
*lock
, int node_id
);
833 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
834 extern struct request_queue
*blk_init_allocated_queue(struct request_queue
*,
835 request_fn_proc
*, spinlock_t
*);
836 extern void blk_cleanup_queue(struct request_queue
*);
837 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
838 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
839 extern void blk_limits_max_hw_sectors(struct queue_limits
*, unsigned int);
840 extern void blk_queue_max_hw_sectors(struct request_queue
*, unsigned int);
841 extern void blk_queue_max_segments(struct request_queue
*, unsigned short);
842 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
843 extern void blk_queue_max_discard_sectors(struct request_queue
*q
,
844 unsigned int max_discard_sectors
);
845 extern void blk_queue_logical_block_size(struct request_queue
*, unsigned short);
846 extern void blk_queue_physical_block_size(struct request_queue
*, unsigned int);
847 extern void blk_queue_alignment_offset(struct request_queue
*q
,
848 unsigned int alignment
);
849 extern void blk_limits_io_min(struct queue_limits
*limits
, unsigned int min
);
850 extern void blk_queue_io_min(struct request_queue
*q
, unsigned int min
);
851 extern void blk_limits_io_opt(struct queue_limits
*limits
, unsigned int opt
);
852 extern void blk_queue_io_opt(struct request_queue
*q
, unsigned int opt
);
853 extern void blk_set_default_limits(struct queue_limits
*lim
);
854 extern void blk_set_stacking_limits(struct queue_limits
*lim
);
855 extern int blk_stack_limits(struct queue_limits
*t
, struct queue_limits
*b
,
857 extern int bdev_stack_limits(struct queue_limits
*t
, struct block_device
*bdev
,
859 extern void disk_stack_limits(struct gendisk
*disk
, struct block_device
*bdev
,
861 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
862 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
863 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
864 extern int blk_queue_dma_drain(struct request_queue
*q
,
865 dma_drain_needed_fn
*dma_drain_needed
,
866 void *buf
, unsigned int size
);
867 extern void blk_queue_lld_busy(struct request_queue
*q
, lld_busy_fn
*fn
);
868 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
869 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
870 extern void blk_queue_unprep_rq(struct request_queue
*, unprep_rq_fn
*ufn
);
871 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
872 extern void blk_queue_dma_alignment(struct request_queue
*, int);
873 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
874 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
875 extern void blk_queue_rq_timed_out(struct request_queue
*, rq_timed_out_fn
*);
876 extern void blk_queue_rq_timeout(struct request_queue
*, unsigned int);
877 extern void blk_queue_flush(struct request_queue
*q
, unsigned int flush
);
878 extern void blk_queue_flush_queueable(struct request_queue
*q
, bool queueable
);
879 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
881 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
882 extern void blk_dump_rq_flags(struct request
*, char *);
883 extern long nr_blockdev_pages(void);
885 bool __must_check
blk_get_queue(struct request_queue
*);
886 struct request_queue
*blk_alloc_queue(gfp_t
);
887 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
888 extern void blk_put_queue(struct request_queue
*);
891 * blk_plug permits building a queue of related requests by holding the I/O
892 * fragments for a short period. This allows merging of sequential requests
893 * into single larger request. As the requests are moved from a per-task list to
894 * the device's request_queue in a batch, this results in improved scalability
895 * as the lock contention for request_queue lock is reduced.
897 * It is ok not to disable preemption when adding the request to the plug list
898 * or when attempting a merge, because blk_schedule_flush_list() will only flush
899 * the plug list when the task sleeps by itself. For details, please see
900 * schedule() where blk_schedule_flush_plug() is called.
903 unsigned long magic
; /* detect uninitialized use-cases */
904 struct list_head list
; /* requests */
905 struct list_head cb_list
; /* md requires an unplug callback */
906 unsigned int should_sort
; /* list to be sorted before flushing? */
908 #define BLK_MAX_REQUEST_COUNT 16
911 struct list_head list
;
912 void (*callback
)(struct blk_plug_cb
*);
915 extern void blk_start_plug(struct blk_plug
*);
916 extern void blk_finish_plug(struct blk_plug
*);
917 extern void blk_flush_plug_list(struct blk_plug
*, bool);
919 static inline void blk_flush_plug(struct task_struct
*tsk
)
921 struct blk_plug
*plug
= tsk
->plug
;
924 blk_flush_plug_list(plug
, false);
927 static inline void blk_schedule_flush_plug(struct task_struct
*tsk
)
929 struct blk_plug
*plug
= tsk
->plug
;
932 blk_flush_plug_list(plug
, true);
935 static inline bool blk_needs_flush_plug(struct task_struct
*tsk
)
937 struct blk_plug
*plug
= tsk
->plug
;
939 return plug
&& (!list_empty(&plug
->list
) || !list_empty(&plug
->cb_list
));
945 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
946 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
947 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
948 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
949 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
950 extern void blk_queue_free_tags(struct request_queue
*);
951 extern int blk_queue_resize_tags(struct request_queue
*, int);
952 extern void blk_queue_invalidate_tags(struct request_queue
*);
953 extern struct blk_queue_tag
*blk_init_tags(int);
954 extern void blk_free_tags(struct blk_queue_tag
*);
956 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
959 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
961 return bqt
->tag_index
[tag
];
964 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
966 extern int blkdev_issue_flush(struct block_device
*, gfp_t
, sector_t
*);
967 extern int blkdev_issue_discard(struct block_device
*bdev
, sector_t sector
,
968 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
);
969 extern int blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
970 sector_t nr_sects
, gfp_t gfp_mask
);
971 static inline int sb_issue_discard(struct super_block
*sb
, sector_t block
,
972 sector_t nr_blocks
, gfp_t gfp_mask
, unsigned long flags
)
974 return blkdev_issue_discard(sb
->s_bdev
, block
<< (sb
->s_blocksize_bits
- 9),
975 nr_blocks
<< (sb
->s_blocksize_bits
- 9),
978 static inline int sb_issue_zeroout(struct super_block
*sb
, sector_t block
,
979 sector_t nr_blocks
, gfp_t gfp_mask
)
981 return blkdev_issue_zeroout(sb
->s_bdev
,
982 block
<< (sb
->s_blocksize_bits
- 9),
983 nr_blocks
<< (sb
->s_blocksize_bits
- 9),
987 extern int blk_verify_command(unsigned char *cmd
, fmode_t has_write_perm
);
989 enum blk_default_limits
{
990 BLK_MAX_SEGMENTS
= 128,
991 BLK_SAFE_MAX_SECTORS
= 255,
992 BLK_DEF_MAX_SECTORS
= 1024,
993 BLK_MAX_SEGMENT_SIZE
= 65536,
994 BLK_SEG_BOUNDARY_MASK
= 0xFFFFFFFFUL
,
997 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
999 static inline unsigned long queue_bounce_pfn(struct request_queue
*q
)
1001 return q
->limits
.bounce_pfn
;
1004 static inline unsigned long queue_segment_boundary(struct request_queue
*q
)
1006 return q
->limits
.seg_boundary_mask
;
1009 static inline unsigned int queue_max_sectors(struct request_queue
*q
)
1011 return q
->limits
.max_sectors
;
1014 static inline unsigned int queue_max_hw_sectors(struct request_queue
*q
)
1016 return q
->limits
.max_hw_sectors
;
1019 static inline unsigned short queue_max_segments(struct request_queue
*q
)
1021 return q
->limits
.max_segments
;
1024 static inline unsigned int queue_max_segment_size(struct request_queue
*q
)
1026 return q
->limits
.max_segment_size
;
1029 static inline unsigned short queue_logical_block_size(struct request_queue
*q
)
1033 if (q
&& q
->limits
.logical_block_size
)
1034 retval
= q
->limits
.logical_block_size
;
1039 static inline unsigned short bdev_logical_block_size(struct block_device
*bdev
)
1041 return queue_logical_block_size(bdev_get_queue(bdev
));
1044 static inline unsigned int queue_physical_block_size(struct request_queue
*q
)
1046 return q
->limits
.physical_block_size
;
1049 static inline unsigned int bdev_physical_block_size(struct block_device
*bdev
)
1051 return queue_physical_block_size(bdev_get_queue(bdev
));
1054 static inline unsigned int queue_io_min(struct request_queue
*q
)
1056 return q
->limits
.io_min
;
1059 static inline int bdev_io_min(struct block_device
*bdev
)
1061 return queue_io_min(bdev_get_queue(bdev
));
1064 static inline unsigned int queue_io_opt(struct request_queue
*q
)
1066 return q
->limits
.io_opt
;
1069 static inline int bdev_io_opt(struct block_device
*bdev
)
1071 return queue_io_opt(bdev_get_queue(bdev
));
1074 static inline int queue_alignment_offset(struct request_queue
*q
)
1076 if (q
->limits
.misaligned
)
1079 return q
->limits
.alignment_offset
;
1082 static inline int queue_limit_alignment_offset(struct queue_limits
*lim
, sector_t sector
)
1084 unsigned int granularity
= max(lim
->physical_block_size
, lim
->io_min
);
1085 unsigned int alignment
= (sector
<< 9) & (granularity
- 1);
1087 return (granularity
+ lim
->alignment_offset
- alignment
)
1088 & (granularity
- 1);
1091 static inline int bdev_alignment_offset(struct block_device
*bdev
)
1093 struct request_queue
*q
= bdev_get_queue(bdev
);
1095 if (q
->limits
.misaligned
)
1098 if (bdev
!= bdev
->bd_contains
)
1099 return bdev
->bd_part
->alignment_offset
;
1101 return q
->limits
.alignment_offset
;
1104 static inline int queue_discard_alignment(struct request_queue
*q
)
1106 if (q
->limits
.discard_misaligned
)
1109 return q
->limits
.discard_alignment
;
1112 static inline int queue_limit_discard_alignment(struct queue_limits
*lim
, sector_t sector
)
1114 unsigned int alignment
= (sector
<< 9) & (lim
->discard_granularity
- 1);
1116 if (!lim
->max_discard_sectors
)
1119 return (lim
->discard_granularity
+ lim
->discard_alignment
- alignment
)
1120 & (lim
->discard_granularity
- 1);
1123 static inline unsigned int queue_discard_zeroes_data(struct request_queue
*q
)
1125 if (q
->limits
.max_discard_sectors
&& q
->limits
.discard_zeroes_data
== 1)
1131 static inline unsigned int bdev_discard_zeroes_data(struct block_device
*bdev
)
1133 return queue_discard_zeroes_data(bdev_get_queue(bdev
));
1136 static inline int queue_dma_alignment(struct request_queue
*q
)
1138 return q
? q
->dma_alignment
: 511;
1141 static inline int blk_rq_aligned(struct request_queue
*q
, unsigned long addr
,
1144 unsigned int alignment
= queue_dma_alignment(q
) | q
->dma_pad_mask
;
1145 return !(addr
& alignment
) && !(len
& alignment
);
1148 /* assumes size > 256 */
1149 static inline unsigned int blksize_bits(unsigned int size
)
1151 unsigned int bits
= 8;
1155 } while (size
> 256);
1159 static inline unsigned int block_size(struct block_device
*bdev
)
1161 return bdev
->bd_block_size
;
1164 static inline bool queue_flush_queueable(struct request_queue
*q
)
1166 return !q
->flush_not_queueable
;
1169 typedef struct {struct page
*v
;} Sector
;
1171 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
1173 static inline void put_dev_sector(Sector p
)
1175 page_cache_release(p
.v
);
1179 int kblockd_schedule_work(struct request_queue
*q
, struct work_struct
*work
);
1181 #ifdef CONFIG_BLK_CGROUP
1183 * This should not be using sched_clock(). A real patch is in progress
1184 * to fix this up, until that is in place we need to disable preemption
1185 * around sched_clock() in this function and set_io_start_time_ns().
1187 static inline void set_start_time_ns(struct request
*req
)
1190 req
->start_time_ns
= sched_clock();
1194 static inline void set_io_start_time_ns(struct request
*req
)
1197 req
->io_start_time_ns
= sched_clock();
1201 static inline uint64_t rq_start_time_ns(struct request
*req
)
1203 return req
->start_time_ns
;
1206 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1208 return req
->io_start_time_ns
;
1211 static inline void set_start_time_ns(struct request
*req
) {}
1212 static inline void set_io_start_time_ns(struct request
*req
) {}
1213 static inline uint64_t rq_start_time_ns(struct request
*req
)
1217 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1223 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1224 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1225 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1226 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1228 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1230 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1231 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1233 struct blk_integrity_exchg
{
1237 unsigned int data_size
;
1238 unsigned short sector_size
;
1239 const char *disk_name
;
1242 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
1243 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
1244 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
1245 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
1247 struct blk_integrity
{
1248 integrity_gen_fn
*generate_fn
;
1249 integrity_vrfy_fn
*verify_fn
;
1250 integrity_set_tag_fn
*set_tag_fn
;
1251 integrity_get_tag_fn
*get_tag_fn
;
1253 unsigned short flags
;
1254 unsigned short tuple_size
;
1255 unsigned short sector_size
;
1256 unsigned short tag_size
;
1260 struct kobject kobj
;
1263 extern bool blk_integrity_is_initialized(struct gendisk
*);
1264 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
1265 extern void blk_integrity_unregister(struct gendisk
*);
1266 extern int blk_integrity_compare(struct gendisk
*, struct gendisk
*);
1267 extern int blk_rq_map_integrity_sg(struct request_queue
*, struct bio
*,
1268 struct scatterlist
*);
1269 extern int blk_rq_count_integrity_sg(struct request_queue
*, struct bio
*);
1270 extern int blk_integrity_merge_rq(struct request_queue
*, struct request
*,
1272 extern int blk_integrity_merge_bio(struct request_queue
*, struct request
*,
1276 struct blk_integrity
*bdev_get_integrity(struct block_device
*bdev
)
1278 return bdev
->bd_disk
->integrity
;
1281 static inline struct blk_integrity
*blk_get_integrity(struct gendisk
*disk
)
1283 return disk
->integrity
;
1286 static inline int blk_integrity_rq(struct request
*rq
)
1288 if (rq
->bio
== NULL
)
1291 return bio_integrity(rq
->bio
);
1294 static inline void blk_queue_max_integrity_segments(struct request_queue
*q
,
1297 q
->limits
.max_integrity_segments
= segs
;
1300 static inline unsigned short
1301 queue_max_integrity_segments(struct request_queue
*q
)
1303 return q
->limits
.max_integrity_segments
;
1306 #else /* CONFIG_BLK_DEV_INTEGRITY */
1309 struct block_device
;
1311 struct blk_integrity
;
1313 static inline int blk_integrity_rq(struct request
*rq
)
1317 static inline int blk_rq_count_integrity_sg(struct request_queue
*q
,
1322 static inline int blk_rq_map_integrity_sg(struct request_queue
*q
,
1324 struct scatterlist
*s
)
1328 static inline struct blk_integrity
*bdev_get_integrity(struct block_device
*b
)
1332 static inline struct blk_integrity
*blk_get_integrity(struct gendisk
*disk
)
1336 static inline int blk_integrity_compare(struct gendisk
*a
, struct gendisk
*b
)
1340 static inline int blk_integrity_register(struct gendisk
*d
,
1341 struct blk_integrity
*b
)
1345 static inline void blk_integrity_unregister(struct gendisk
*d
)
1348 static inline void blk_queue_max_integrity_segments(struct request_queue
*q
,
1352 static inline unsigned short queue_max_integrity_segments(struct request_queue
*q
)
1356 static inline int blk_integrity_merge_rq(struct request_queue
*rq
,
1362 static inline int blk_integrity_merge_bio(struct request_queue
*rq
,
1368 static inline bool blk_integrity_is_initialized(struct gendisk
*g
)
1373 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1375 struct block_device_operations
{
1376 int (*open
) (struct block_device
*, fmode_t
);
1377 int (*release
) (struct gendisk
*, fmode_t
);
1378 int (*ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1379 int (*compat_ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1380 int (*direct_access
) (struct block_device
*, sector_t
,
1381 void **, unsigned long *);
1382 unsigned int (*check_events
) (struct gendisk
*disk
,
1383 unsigned int clearing
);
1384 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1385 int (*media_changed
) (struct gendisk
*);
1386 void (*unlock_native_capacity
) (struct gendisk
*);
1387 int (*revalidate_disk
) (struct gendisk
*);
1388 int (*getgeo
)(struct block_device
*, struct hd_geometry
*);
1389 /* this callback is with swap_lock and sometimes page table lock held */
1390 void (*swap_slot_free_notify
) (struct block_device
*, unsigned long);
1391 struct module
*owner
;
1394 extern int __blkdev_driver_ioctl(struct block_device
*, fmode_t
, unsigned int,
1396 #else /* CONFIG_BLOCK */
1398 * stubs for when the block layer is configured out
1400 #define buffer_heads_over_limit 0
1402 static inline long nr_blockdev_pages(void)
1410 static inline void blk_start_plug(struct blk_plug
*plug
)
1414 static inline void blk_finish_plug(struct blk_plug
*plug
)
1418 static inline void blk_flush_plug(struct task_struct
*task
)
1422 static inline void blk_schedule_flush_plug(struct task_struct
*task
)
1427 static inline bool blk_needs_flush_plug(struct task_struct
*tsk
)
1432 #endif /* CONFIG_BLOCK */