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/module.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>
25 struct scsi_ioctl_command
;
28 struct elevator_queue
;
29 struct request_pm_state
;
34 #define BLKDEV_MIN_RQ 4
35 #define BLKDEV_MAX_RQ 128 /* Default maximum */
38 typedef void (rq_end_io_fn
)(struct request
*, int);
42 * count[], starved[], and wait[] are indexed by
43 * BLK_RW_SYNC/BLK_RW_ASYNC
49 wait_queue_head_t wait
[2];
53 * request command types
55 enum rq_cmd_type_bits
{
56 REQ_TYPE_FS
= 1, /* fs request */
57 REQ_TYPE_BLOCK_PC
, /* scsi command */
58 REQ_TYPE_SENSE
, /* sense request */
59 REQ_TYPE_PM_SUSPEND
, /* suspend request */
60 REQ_TYPE_PM_RESUME
, /* resume request */
61 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
62 REQ_TYPE_SPECIAL
, /* driver defined type */
63 REQ_TYPE_LINUX_BLOCK
, /* generic block layer message */
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
,
74 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
75 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
78 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
79 * typically to differentiate REQ_TYPE_SPECIAL requests.
83 REQ_LB_OP_EJECT
= 0x40, /* eject request */
84 REQ_LB_OP_FLUSH
= 0x41, /* flush request */
87 #define BLK_MAX_CDB 16
90 * try to put the fields that are referenced together in the same cacheline.
91 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
95 struct list_head queuelist
;
96 struct call_single_data csd
;
98 struct request_queue
*q
;
100 unsigned int cmd_flags
;
101 enum rq_cmd_type_bits cmd_type
;
102 unsigned long atomic_flags
;
106 /* the following two fields are internal, NEVER access directly */
107 unsigned int __data_len
; /* total data len */
108 sector_t __sector
; /* sector cursor */
113 struct hlist_node hash
; /* merge hash */
115 * The rb_node is only used inside the io scheduler, requests
116 * are pruned when moved to the dispatch queue. So let the
117 * completion_data share space with the rb_node.
120 struct rb_node rb_node
; /* sort/lookup */
121 void *completion_data
;
125 * Three pointers are available for the IO schedulers, if they need
126 * more they have to dynamically allocate it.
128 void *elevator_private
;
129 void *elevator_private2
;
130 void *elevator_private3
;
132 struct gendisk
*rq_disk
;
133 unsigned long start_time
;
134 #ifdef CONFIG_BLK_CGROUP
135 unsigned long long start_time_ns
;
136 unsigned long long io_start_time_ns
; /* when passed to hardware */
138 /* Number of scatter-gather DMA addr+len pairs after
139 * physical address coalescing is performed.
141 unsigned short nr_phys_segments
;
143 unsigned short ioprio
;
147 void *special
; /* opaque pointer available for LLD use */
148 char *buffer
; /* kaddr of the current segment if available */
154 * when request is used as a packet command carrier
156 unsigned char __cmd
[BLK_MAX_CDB
];
158 unsigned short cmd_len
;
160 unsigned int extra_len
; /* length of alignment and padding */
161 unsigned int sense_len
;
162 unsigned int resid_len
; /* residual count */
165 unsigned long deadline
;
166 struct list_head timeout_list
;
167 unsigned int timeout
;
171 * completion callback.
173 rq_end_io_fn
*end_io
;
177 struct request
*next_rq
;
180 static inline unsigned short req_get_ioprio(struct request
*req
)
186 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
187 * requests. Some step values could eventually be made generic.
189 struct request_pm_state
191 /* PM state machine step value, currently driver specific */
193 /* requested PM state value (S1, S2, S3, S4, ...) */
195 void* data
; /* for driver use */
198 #include <linux/elevator.h>
200 typedef void (request_fn_proc
) (struct request_queue
*q
);
201 typedef int (make_request_fn
) (struct request_queue
*q
, struct bio
*bio
);
202 typedef int (prep_rq_fn
) (struct request_queue
*, struct request
*);
203 typedef void (unprep_rq_fn
) (struct request_queue
*, struct request
*);
204 typedef void (unplug_fn
) (struct request_queue
*);
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
);
219 enum blk_eh_timer_return
{
225 typedef enum blk_eh_timer_return (rq_timed_out_fn
)(struct request
*);
227 enum blk_queue_state
{
232 struct blk_queue_tag
{
233 struct request
**tag_index
; /* map of busy tags */
234 unsigned long *tag_map
; /* bit map of free/busy tags */
235 int busy
; /* current depth */
236 int max_depth
; /* what we will send to device */
237 int real_max_depth
; /* what the array can hold */
238 atomic_t refcnt
; /* map can be shared */
241 #define BLK_SCSI_MAX_CMDS (256)
242 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
244 struct queue_limits
{
245 unsigned long bounce_pfn
;
246 unsigned long seg_boundary_mask
;
248 unsigned int max_hw_sectors
;
249 unsigned int max_sectors
;
250 unsigned int max_segment_size
;
251 unsigned int physical_block_size
;
252 unsigned int alignment_offset
;
255 unsigned int max_discard_sectors
;
256 unsigned int discard_granularity
;
257 unsigned int discard_alignment
;
259 unsigned short logical_block_size
;
260 unsigned short max_segments
;
262 unsigned char misaligned
;
263 unsigned char discard_misaligned
;
264 unsigned char no_cluster
;
265 signed char discard_zeroes_data
;
271 * Together with queue_head for cacheline sharing
273 struct list_head queue_head
;
274 struct request
*last_merge
;
275 struct elevator_queue
*elevator
;
278 * the queue request freelist, one for reads and one for writes
280 struct request_list rq
;
282 request_fn_proc
*request_fn
;
283 make_request_fn
*make_request_fn
;
284 prep_rq_fn
*prep_rq_fn
;
285 unprep_rq_fn
*unprep_rq_fn
;
286 unplug_fn
*unplug_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 * Auto-unplugging state
302 struct timer_list unplug_timer
;
303 int unplug_thresh
; /* After this many requests */
304 unsigned long unplug_delay
; /* After this many jiffies */
305 struct work_struct unplug_work
;
307 struct backing_dev_info backing_dev_info
;
310 * The queue owner gets to use this for whatever they like.
311 * ll_rw_blk doesn't touch it.
316 * queue needs bounce pages for pages above this limit
321 * various queue flags, see QUEUE_* below
323 unsigned long queue_flags
;
326 * protects queue structures from reentrancy. ->__queue_lock should
327 * _never_ be used directly, it is queue private. always use
330 spinlock_t __queue_lock
;
331 spinlock_t
*queue_lock
;
341 unsigned long nr_requests
; /* Max # of requests */
342 unsigned int nr_congestion_on
;
343 unsigned int nr_congestion_off
;
344 unsigned int nr_batching
;
346 void *dma_drain_buffer
;
347 unsigned int dma_drain_size
;
348 unsigned int dma_pad_mask
;
349 unsigned int dma_alignment
;
351 struct blk_queue_tag
*queue_tags
;
352 struct list_head tag_busy_list
;
354 unsigned int nr_sorted
;
355 unsigned int in_flight
[2];
357 unsigned int rq_timeout
;
358 struct timer_list timeout
;
359 struct list_head timeout_list
;
361 struct queue_limits limits
;
366 unsigned int sg_timeout
;
367 unsigned int sg_reserved_size
;
369 #ifdef CONFIG_BLK_DEV_IO_TRACE
370 struct blk_trace
*blk_trace
;
373 * reserved for flush operations
375 unsigned int ordered
, next_ordered
, ordseq
;
376 int orderr
, ordcolor
;
377 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
378 struct request
*orig_bar_rq
;
380 struct mutex sysfs_lock
;
382 #if defined(CONFIG_BLK_DEV_BSG)
383 struct bsg_class_device bsg_dev
;
387 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
388 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
389 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
390 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
391 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
392 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
393 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
394 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
395 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
396 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
397 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
398 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
399 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
400 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
401 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
402 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
403 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
404 #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */
405 #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */
406 #define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */
408 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
409 (1 << QUEUE_FLAG_CLUSTER) | \
410 (1 << QUEUE_FLAG_STACKABLE) | \
411 (1 << QUEUE_FLAG_SAME_COMP) | \
412 (1 << QUEUE_FLAG_ADD_RANDOM))
414 static inline int queue_is_locked(struct request_queue
*q
)
417 spinlock_t
*lock
= q
->queue_lock
;
418 return lock
&& spin_is_locked(lock
);
424 static inline void queue_flag_set_unlocked(unsigned int flag
,
425 struct request_queue
*q
)
427 __set_bit(flag
, &q
->queue_flags
);
430 static inline int queue_flag_test_and_clear(unsigned int flag
,
431 struct request_queue
*q
)
433 WARN_ON_ONCE(!queue_is_locked(q
));
435 if (test_bit(flag
, &q
->queue_flags
)) {
436 __clear_bit(flag
, &q
->queue_flags
);
443 static inline int queue_flag_test_and_set(unsigned int flag
,
444 struct request_queue
*q
)
446 WARN_ON_ONCE(!queue_is_locked(q
));
448 if (!test_bit(flag
, &q
->queue_flags
)) {
449 __set_bit(flag
, &q
->queue_flags
);
456 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
458 WARN_ON_ONCE(!queue_is_locked(q
));
459 __set_bit(flag
, &q
->queue_flags
);
462 static inline void queue_flag_clear_unlocked(unsigned int flag
,
463 struct request_queue
*q
)
465 __clear_bit(flag
, &q
->queue_flags
);
468 static inline int queue_in_flight(struct request_queue
*q
)
470 return q
->in_flight
[0] + q
->in_flight
[1];
473 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
475 WARN_ON_ONCE(!queue_is_locked(q
));
476 __clear_bit(flag
, &q
->queue_flags
);
481 * Hardbarrier is supported with one of the following methods.
483 * NONE : hardbarrier unsupported
484 * DRAIN : ordering by draining is enough
485 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
486 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
487 * TAG : ordering by tag is enough
488 * TAG_FLUSH : ordering by tag w/ pre and post flushes
489 * TAG_FUA : ordering by tag w/ pre flush and FUA write
491 QUEUE_ORDERED_BY_DRAIN
= 0x01,
492 QUEUE_ORDERED_BY_TAG
= 0x02,
493 QUEUE_ORDERED_DO_PREFLUSH
= 0x10,
494 QUEUE_ORDERED_DO_BAR
= 0x20,
495 QUEUE_ORDERED_DO_POSTFLUSH
= 0x40,
496 QUEUE_ORDERED_DO_FUA
= 0x80,
498 QUEUE_ORDERED_NONE
= 0x00,
500 QUEUE_ORDERED_DRAIN
= QUEUE_ORDERED_BY_DRAIN
|
501 QUEUE_ORDERED_DO_BAR
,
502 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
503 QUEUE_ORDERED_DO_PREFLUSH
|
504 QUEUE_ORDERED_DO_POSTFLUSH
,
505 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
506 QUEUE_ORDERED_DO_PREFLUSH
|
507 QUEUE_ORDERED_DO_FUA
,
509 QUEUE_ORDERED_TAG
= QUEUE_ORDERED_BY_TAG
|
510 QUEUE_ORDERED_DO_BAR
,
511 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
512 QUEUE_ORDERED_DO_PREFLUSH
|
513 QUEUE_ORDERED_DO_POSTFLUSH
,
514 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
515 QUEUE_ORDERED_DO_PREFLUSH
|
516 QUEUE_ORDERED_DO_FUA
,
519 * Ordered operation sequence
521 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
522 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
523 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
524 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
525 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
526 QUEUE_ORDSEQ_DONE
= 0x20,
529 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
530 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
531 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
532 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
533 #define blk_queue_noxmerges(q) \
534 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
535 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
536 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
537 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
538 #define blk_queue_flushing(q) ((q)->ordseq)
539 #define blk_queue_stackable(q) \
540 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
541 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
543 #define blk_noretry_request(rq) \
544 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
545 REQ_FAILFAST_DRIVER))
547 #define blk_account_rq(rq) \
548 (((rq)->cmd_flags & REQ_STARTED) && \
549 ((rq)->cmd_type == REQ_TYPE_FS || \
550 ((rq)->cmd_flags & REQ_DISCARD)))
552 #define blk_pm_request(rq) \
553 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
554 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
556 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
557 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
558 /* rq->queuelist of dequeued request must be list_empty() */
559 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
561 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
563 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
566 * We regard a request as sync, if either a read or a sync write
568 static inline bool rw_is_sync(unsigned int rw_flags
)
570 return !(rw_flags
& REQ_WRITE
) || (rw_flags
& REQ_SYNC
);
573 static inline bool rq_is_sync(struct request
*rq
)
575 return rw_is_sync(rq
->cmd_flags
);
578 static inline int blk_queue_full(struct request_queue
*q
, int sync
)
581 return test_bit(QUEUE_FLAG_SYNCFULL
, &q
->queue_flags
);
582 return test_bit(QUEUE_FLAG_ASYNCFULL
, &q
->queue_flags
);
585 static inline void blk_set_queue_full(struct request_queue
*q
, int sync
)
588 queue_flag_set(QUEUE_FLAG_SYNCFULL
, q
);
590 queue_flag_set(QUEUE_FLAG_ASYNCFULL
, q
);
593 static inline void blk_clear_queue_full(struct request_queue
*q
, int sync
)
596 queue_flag_clear(QUEUE_FLAG_SYNCFULL
, q
);
598 queue_flag_clear(QUEUE_FLAG_ASYNCFULL
, q
);
603 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
604 * it already be started by driver.
606 #define RQ_NOMERGE_FLAGS \
607 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
608 #define rq_mergeable(rq) \
609 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
610 (((rq)->cmd_flags & REQ_DISCARD) || \
611 (rq)->cmd_type == REQ_TYPE_FS))
614 * q->prep_rq_fn return values
616 #define BLKPREP_OK 0 /* serve it */
617 #define BLKPREP_KILL 1 /* fatal error, kill */
618 #define BLKPREP_DEFER 2 /* leave on queue */
620 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
623 * standard bounce addresses:
625 * BLK_BOUNCE_HIGH : bounce all highmem pages
626 * BLK_BOUNCE_ANY : don't bounce anything
627 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
630 #if BITS_PER_LONG == 32
631 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
633 #define BLK_BOUNCE_HIGH -1ULL
635 #define BLK_BOUNCE_ANY (-1ULL)
636 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
639 * default timeout for SG_IO if none specified
641 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
642 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
645 extern int init_emergency_isa_pool(void);
646 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
648 static inline int init_emergency_isa_pool(void)
652 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
655 #endif /* CONFIG_MMU */
661 unsigned long offset
;
666 struct req_iterator
{
671 /* This should not be used directly - use rq_for_each_segment */
672 #define for_each_bio(_bio) \
673 for (; _bio; _bio = _bio->bi_next)
674 #define __rq_for_each_bio(_bio, rq) \
676 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
678 #define rq_for_each_segment(bvl, _rq, _iter) \
679 __rq_for_each_bio(_iter.bio, _rq) \
680 bio_for_each_segment(bvl, _iter.bio, _iter.i)
682 #define rq_iter_last(rq, _iter) \
683 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
685 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
686 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
688 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
689 extern void rq_flush_dcache_pages(struct request
*rq
);
691 static inline void rq_flush_dcache_pages(struct request
*rq
)
696 extern int blk_register_queue(struct gendisk
*disk
);
697 extern void blk_unregister_queue(struct gendisk
*disk
);
698 extern void register_disk(struct gendisk
*dev
);
699 extern void generic_make_request(struct bio
*bio
);
700 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
701 extern void blk_put_request(struct request
*);
702 extern void __blk_put_request(struct request_queue
*, struct request
*);
703 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
704 extern struct request
*blk_make_request(struct request_queue
*, struct bio
*,
706 extern void blk_insert_request(struct request_queue
*, struct request
*, int, void *);
707 extern void blk_requeue_request(struct request_queue
*, struct request
*);
708 extern void blk_add_request_payload(struct request
*rq
, struct page
*page
,
710 extern int blk_rq_check_limits(struct request_queue
*q
, struct request
*rq
);
711 extern int blk_lld_busy(struct request_queue
*q
);
712 extern int blk_rq_prep_clone(struct request
*rq
, struct request
*rq_src
,
713 struct bio_set
*bs
, gfp_t gfp_mask
,
714 int (*bio_ctr
)(struct bio
*, struct bio
*, void *),
716 extern void blk_rq_unprep_clone(struct request
*rq
);
717 extern int blk_insert_cloned_request(struct request_queue
*q
,
719 extern void blk_plug_device(struct request_queue
*);
720 extern void blk_plug_device_unlocked(struct request_queue
*);
721 extern int blk_remove_plug(struct request_queue
*);
722 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
723 extern int scsi_cmd_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
724 unsigned int, void __user
*);
725 extern int sg_scsi_ioctl(struct request_queue
*, struct gendisk
*, fmode_t
,
726 struct scsi_ioctl_command __user
*);
729 * A queue has just exitted congestion. Note this in the global counter of
730 * congested queues, and wake up anyone who was waiting for requests to be
733 static inline void blk_clear_queue_congested(struct request_queue
*q
, int sync
)
735 clear_bdi_congested(&q
->backing_dev_info
, sync
);
739 * A queue has just entered congestion. Flag that in the queue's VM-visible
740 * state flags and increment the global gounter of congested queues.
742 static inline void blk_set_queue_congested(struct request_queue
*q
, int sync
)
744 set_bdi_congested(&q
->backing_dev_info
, sync
);
747 extern void blk_start_queue(struct request_queue
*q
);
748 extern void blk_stop_queue(struct request_queue
*q
);
749 extern void blk_sync_queue(struct request_queue
*q
);
750 extern void __blk_stop_queue(struct request_queue
*q
);
751 extern void __blk_run_queue(struct request_queue
*);
752 extern void blk_run_queue(struct request_queue
*);
753 extern int blk_rq_map_user(struct request_queue
*, struct request
*,
754 struct rq_map_data
*, void __user
*, unsigned long,
756 extern int blk_rq_unmap_user(struct bio
*);
757 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
758 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
759 struct rq_map_data
*, struct sg_iovec
*, int,
760 unsigned int, gfp_t
);
761 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
762 struct request
*, int);
763 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
764 struct request
*, int, rq_end_io_fn
*);
765 extern void blk_unplug(struct request_queue
*q
);
767 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
769 return bdev
->bd_disk
->queue
;
773 * blk_rq_pos() : the current sector
774 * blk_rq_bytes() : bytes left in the entire request
775 * blk_rq_cur_bytes() : bytes left in the current segment
776 * blk_rq_err_bytes() : bytes left till the next error boundary
777 * blk_rq_sectors() : sectors left in the entire request
778 * blk_rq_cur_sectors() : sectors left in the current segment
780 static inline sector_t
blk_rq_pos(const struct request
*rq
)
785 static inline unsigned int blk_rq_bytes(const struct request
*rq
)
787 return rq
->__data_len
;
790 static inline int blk_rq_cur_bytes(const struct request
*rq
)
792 return rq
->bio
? bio_cur_bytes(rq
->bio
) : 0;
795 extern unsigned int blk_rq_err_bytes(const struct request
*rq
);
797 static inline unsigned int blk_rq_sectors(const struct request
*rq
)
799 return blk_rq_bytes(rq
) >> 9;
802 static inline unsigned int blk_rq_cur_sectors(const struct request
*rq
)
804 return blk_rq_cur_bytes(rq
) >> 9;
808 * Request issue related functions.
810 extern struct request
*blk_peek_request(struct request_queue
*q
);
811 extern void blk_start_request(struct request
*rq
);
812 extern struct request
*blk_fetch_request(struct request_queue
*q
);
815 * Request completion related functions.
817 * blk_update_request() completes given number of bytes and updates
818 * the request without completing it.
820 * blk_end_request() and friends. __blk_end_request() must be called
821 * with the request queue spinlock acquired.
823 * Several drivers define their own end_request and call
824 * blk_end_request() for parts of the original function.
825 * This prevents code duplication in drivers.
827 extern bool blk_update_request(struct request
*rq
, int error
,
828 unsigned int nr_bytes
);
829 extern bool blk_end_request(struct request
*rq
, int error
,
830 unsigned int nr_bytes
);
831 extern void blk_end_request_all(struct request
*rq
, int error
);
832 extern bool blk_end_request_cur(struct request
*rq
, int error
);
833 extern bool blk_end_request_err(struct request
*rq
, int error
);
834 extern bool __blk_end_request(struct request
*rq
, int error
,
835 unsigned int nr_bytes
);
836 extern void __blk_end_request_all(struct request
*rq
, int error
);
837 extern bool __blk_end_request_cur(struct request
*rq
, int error
);
838 extern bool __blk_end_request_err(struct request
*rq
, int error
);
840 extern void blk_complete_request(struct request
*);
841 extern void __blk_complete_request(struct request
*);
842 extern void blk_abort_request(struct request
*);
843 extern void blk_abort_queue(struct request_queue
*);
844 extern void blk_unprep_request(struct request
*);
847 * Access functions for manipulating queue properties
849 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
850 spinlock_t
*lock
, int node_id
);
851 extern struct request_queue
*blk_init_allocated_queue_node(struct request_queue
*,
853 spinlock_t
*, int node_id
);
854 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
855 extern struct request_queue
*blk_init_allocated_queue(struct request_queue
*,
856 request_fn_proc
*, spinlock_t
*);
857 extern void blk_cleanup_queue(struct request_queue
*);
858 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
859 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
860 extern void blk_queue_max_hw_sectors(struct request_queue
*, unsigned int);
861 extern void blk_queue_max_segments(struct request_queue
*, unsigned short);
862 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
863 extern void blk_queue_max_discard_sectors(struct request_queue
*q
,
864 unsigned int max_discard_sectors
);
865 extern void blk_queue_logical_block_size(struct request_queue
*, unsigned short);
866 extern void blk_queue_physical_block_size(struct request_queue
*, unsigned short);
867 extern void blk_queue_alignment_offset(struct request_queue
*q
,
868 unsigned int alignment
);
869 extern void blk_limits_io_min(struct queue_limits
*limits
, unsigned int min
);
870 extern void blk_queue_io_min(struct request_queue
*q
, unsigned int min
);
871 extern void blk_limits_io_opt(struct queue_limits
*limits
, unsigned int opt
);
872 extern void blk_queue_io_opt(struct request_queue
*q
, unsigned int opt
);
873 extern void blk_set_default_limits(struct queue_limits
*lim
);
874 extern int blk_stack_limits(struct queue_limits
*t
, struct queue_limits
*b
,
876 extern int bdev_stack_limits(struct queue_limits
*t
, struct block_device
*bdev
,
878 extern void disk_stack_limits(struct gendisk
*disk
, struct block_device
*bdev
,
880 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
881 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
882 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
883 extern int blk_queue_dma_drain(struct request_queue
*q
,
884 dma_drain_needed_fn
*dma_drain_needed
,
885 void *buf
, unsigned int size
);
886 extern void blk_queue_lld_busy(struct request_queue
*q
, lld_busy_fn
*fn
);
887 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
888 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
889 extern void blk_queue_unprep_rq(struct request_queue
*, unprep_rq_fn
*ufn
);
890 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
891 extern void blk_queue_dma_alignment(struct request_queue
*, int);
892 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
893 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
894 extern void blk_queue_rq_timed_out(struct request_queue
*, rq_timed_out_fn
*);
895 extern void blk_queue_rq_timeout(struct request_queue
*, unsigned int);
896 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
897 extern int blk_queue_ordered(struct request_queue
*, unsigned);
898 extern bool blk_do_ordered(struct request_queue
*, struct request
**);
899 extern unsigned blk_ordered_cur_seq(struct request_queue
*);
900 extern unsigned blk_ordered_req_seq(struct request
*);
901 extern bool blk_ordered_complete_seq(struct request_queue
*, unsigned, int);
903 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
904 extern void blk_dump_rq_flags(struct request
*, char *);
905 extern void generic_unplug_device(struct request_queue
*);
906 extern long nr_blockdev_pages(void);
908 int blk_get_queue(struct request_queue
*);
909 struct request_queue
*blk_alloc_queue(gfp_t
);
910 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
911 extern void blk_put_queue(struct request_queue
*);
916 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
917 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
918 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
919 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
920 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
921 extern void blk_queue_free_tags(struct request_queue
*);
922 extern int blk_queue_resize_tags(struct request_queue
*, int);
923 extern void blk_queue_invalidate_tags(struct request_queue
*);
924 extern struct blk_queue_tag
*blk_init_tags(int);
925 extern void blk_free_tags(struct blk_queue_tag
*);
927 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
930 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
932 return bqt
->tag_index
[tag
];
935 BLKDEV_WAIT
, /* wait for completion */
936 BLKDEV_BARRIER
, /*issue request with barrier */
938 #define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
939 #define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER)
940 extern int blkdev_issue_flush(struct block_device
*, gfp_t
, sector_t
*,
942 extern int blkdev_issue_discard(struct block_device
*bdev
, sector_t sector
,
943 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
);
944 extern int blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
945 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
);
946 static inline int sb_issue_discard(struct super_block
*sb
,
947 sector_t block
, sector_t nr_blocks
)
949 block
<<= (sb
->s_blocksize_bits
- 9);
950 nr_blocks
<<= (sb
->s_blocksize_bits
- 9);
951 return blkdev_issue_discard(sb
->s_bdev
, block
, nr_blocks
, GFP_KERNEL
,
952 BLKDEV_IFL_WAIT
| BLKDEV_IFL_BARRIER
);
955 extern int blk_verify_command(unsigned char *cmd
, fmode_t has_write_perm
);
957 enum blk_default_limits
{
958 BLK_MAX_SEGMENTS
= 128,
959 BLK_SAFE_MAX_SECTORS
= 255,
960 BLK_DEF_MAX_SECTORS
= 1024,
961 BLK_MAX_SEGMENT_SIZE
= 65536,
962 BLK_SEG_BOUNDARY_MASK
= 0xFFFFFFFFUL
,
965 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
967 static inline unsigned long queue_bounce_pfn(struct request_queue
*q
)
969 return q
->limits
.bounce_pfn
;
972 static inline unsigned long queue_segment_boundary(struct request_queue
*q
)
974 return q
->limits
.seg_boundary_mask
;
977 static inline unsigned int queue_max_sectors(struct request_queue
*q
)
979 return q
->limits
.max_sectors
;
982 static inline unsigned int queue_max_hw_sectors(struct request_queue
*q
)
984 return q
->limits
.max_hw_sectors
;
987 static inline unsigned short queue_max_segments(struct request_queue
*q
)
989 return q
->limits
.max_segments
;
992 static inline unsigned int queue_max_segment_size(struct request_queue
*q
)
994 return q
->limits
.max_segment_size
;
997 static inline unsigned short queue_logical_block_size(struct request_queue
*q
)
1001 if (q
&& q
->limits
.logical_block_size
)
1002 retval
= q
->limits
.logical_block_size
;
1007 static inline unsigned short bdev_logical_block_size(struct block_device
*bdev
)
1009 return queue_logical_block_size(bdev_get_queue(bdev
));
1012 static inline unsigned int queue_physical_block_size(struct request_queue
*q
)
1014 return q
->limits
.physical_block_size
;
1017 static inline int bdev_physical_block_size(struct block_device
*bdev
)
1019 return queue_physical_block_size(bdev_get_queue(bdev
));
1022 static inline unsigned int queue_io_min(struct request_queue
*q
)
1024 return q
->limits
.io_min
;
1027 static inline int bdev_io_min(struct block_device
*bdev
)
1029 return queue_io_min(bdev_get_queue(bdev
));
1032 static inline unsigned int queue_io_opt(struct request_queue
*q
)
1034 return q
->limits
.io_opt
;
1037 static inline int bdev_io_opt(struct block_device
*bdev
)
1039 return queue_io_opt(bdev_get_queue(bdev
));
1042 static inline int queue_alignment_offset(struct request_queue
*q
)
1044 if (q
->limits
.misaligned
)
1047 return q
->limits
.alignment_offset
;
1050 static inline int queue_limit_alignment_offset(struct queue_limits
*lim
, sector_t sector
)
1052 unsigned int granularity
= max(lim
->physical_block_size
, lim
->io_min
);
1053 unsigned int alignment
= (sector
<< 9) & (granularity
- 1);
1055 return (granularity
+ lim
->alignment_offset
- alignment
)
1056 & (granularity
- 1);
1059 static inline int bdev_alignment_offset(struct block_device
*bdev
)
1061 struct request_queue
*q
= bdev_get_queue(bdev
);
1063 if (q
->limits
.misaligned
)
1066 if (bdev
!= bdev
->bd_contains
)
1067 return bdev
->bd_part
->alignment_offset
;
1069 return q
->limits
.alignment_offset
;
1072 static inline int queue_discard_alignment(struct request_queue
*q
)
1074 if (q
->limits
.discard_misaligned
)
1077 return q
->limits
.discard_alignment
;
1080 static inline int queue_limit_discard_alignment(struct queue_limits
*lim
, sector_t sector
)
1082 unsigned int alignment
= (sector
<< 9) & (lim
->discard_granularity
- 1);
1084 return (lim
->discard_granularity
+ lim
->discard_alignment
- alignment
)
1085 & (lim
->discard_granularity
- 1);
1088 static inline unsigned int queue_discard_zeroes_data(struct request_queue
*q
)
1090 if (q
->limits
.discard_zeroes_data
== 1)
1096 static inline unsigned int bdev_discard_zeroes_data(struct block_device
*bdev
)
1098 return queue_discard_zeroes_data(bdev_get_queue(bdev
));
1101 static inline int queue_dma_alignment(struct request_queue
*q
)
1103 return q
? q
->dma_alignment
: 511;
1106 static inline int blk_rq_aligned(struct request_queue
*q
, void *addr
,
1109 unsigned int alignment
= queue_dma_alignment(q
) | q
->dma_pad_mask
;
1110 return !((unsigned long)addr
& alignment
) && !(len
& alignment
);
1113 /* assumes size > 256 */
1114 static inline unsigned int blksize_bits(unsigned int size
)
1116 unsigned int bits
= 8;
1120 } while (size
> 256);
1124 static inline unsigned int block_size(struct block_device
*bdev
)
1126 return bdev
->bd_block_size
;
1129 typedef struct {struct page
*v
;} Sector
;
1131 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
1133 static inline void put_dev_sector(Sector p
)
1135 page_cache_release(p
.v
);
1139 int kblockd_schedule_work(struct request_queue
*q
, struct work_struct
*work
);
1141 #ifdef CONFIG_BLK_CGROUP
1143 * This should not be using sched_clock(). A real patch is in progress
1144 * to fix this up, until that is in place we need to disable preemption
1145 * around sched_clock() in this function and set_io_start_time_ns().
1147 static inline void set_start_time_ns(struct request
*req
)
1150 req
->start_time_ns
= sched_clock();
1154 static inline void set_io_start_time_ns(struct request
*req
)
1157 req
->io_start_time_ns
= sched_clock();
1161 static inline uint64_t rq_start_time_ns(struct request
*req
)
1163 return req
->start_time_ns
;
1166 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1168 return req
->io_start_time_ns
;
1171 static inline void set_start_time_ns(struct request
*req
) {}
1172 static inline void set_io_start_time_ns(struct request
*req
) {}
1173 static inline uint64_t rq_start_time_ns(struct request
*req
)
1177 static inline uint64_t rq_io_start_time_ns(struct request
*req
)
1183 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1184 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1185 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1186 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1188 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1190 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1191 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1193 struct blk_integrity_exchg
{
1197 unsigned int data_size
;
1198 unsigned short sector_size
;
1199 const char *disk_name
;
1202 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
1203 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
1204 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
1205 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
1207 struct blk_integrity
{
1208 integrity_gen_fn
*generate_fn
;
1209 integrity_vrfy_fn
*verify_fn
;
1210 integrity_set_tag_fn
*set_tag_fn
;
1211 integrity_get_tag_fn
*get_tag_fn
;
1213 unsigned short flags
;
1214 unsigned short tuple_size
;
1215 unsigned short sector_size
;
1216 unsigned short tag_size
;
1220 struct kobject kobj
;
1223 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
1224 extern void blk_integrity_unregister(struct gendisk
*);
1225 extern int blk_integrity_compare(struct gendisk
*, struct gendisk
*);
1226 extern int blk_rq_map_integrity_sg(struct request
*, struct scatterlist
*);
1227 extern int blk_rq_count_integrity_sg(struct request
*);
1230 struct blk_integrity
*bdev_get_integrity(struct block_device
*bdev
)
1232 return bdev
->bd_disk
->integrity
;
1235 static inline struct blk_integrity
*blk_get_integrity(struct gendisk
*disk
)
1237 return disk
->integrity
;
1240 static inline int blk_integrity_rq(struct request
*rq
)
1242 if (rq
->bio
== NULL
)
1245 return bio_integrity(rq
->bio
);
1248 #else /* CONFIG_BLK_DEV_INTEGRITY */
1250 #define blk_integrity_rq(rq) (0)
1251 #define blk_rq_count_integrity_sg(a) (0)
1252 #define blk_rq_map_integrity_sg(a, b) (0)
1253 #define bdev_get_integrity(a) (0)
1254 #define blk_get_integrity(a) (0)
1255 #define blk_integrity_compare(a, b) (0)
1256 #define blk_integrity_register(a, b) (0)
1257 #define blk_integrity_unregister(a) do { } while (0);
1259 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1261 struct block_device_operations
{
1262 int (*open
) (struct block_device
*, fmode_t
);
1263 int (*release
) (struct gendisk
*, fmode_t
);
1264 int (*locked_ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1265 int (*ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1266 int (*compat_ioctl
) (struct block_device
*, fmode_t
, unsigned, unsigned long);
1267 int (*direct_access
) (struct block_device
*, sector_t
,
1268 void **, unsigned long *);
1269 int (*media_changed
) (struct gendisk
*);
1270 void (*unlock_native_capacity
) (struct gendisk
*);
1271 int (*revalidate_disk
) (struct gendisk
*);
1272 int (*getgeo
)(struct block_device
*, struct hd_geometry
*);
1273 /* this callback is with swap_lock and sometimes page table lock held */
1274 void (*swap_slot_free_notify
) (struct block_device
*, unsigned long);
1275 struct module
*owner
;
1278 extern int __blkdev_driver_ioctl(struct block_device
*, fmode_t
, unsigned int,
1280 #else /* CONFIG_BLOCK */
1282 * stubs for when the block layer is configured out
1284 #define buffer_heads_over_limit 0
1286 static inline long nr_blockdev_pages(void)
1291 #endif /* CONFIG_BLOCK */