1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
4 #include <linux/sched.h>
5 #include <linux/major.h>
6 #include <linux/genhd.h>
7 #include <linux/list.h>
8 #include <linux/timer.h>
9 #include <linux/workqueue.h>
10 #include <linux/pagemap.h>
11 #include <linux/backing-dev.h>
12 #include <linux/wait.h>
13 #include <linux/mempool.h>
14 #include <linux/bio.h>
15 #include <linux/module.h>
16 #include <linux/stringify.h>
18 #include <asm/scatterlist.h>
21 # include <asm/div64.h>
22 # define sector_div(a, b) do_div(a, b)
24 # define sector_div(n, b)( \
36 struct scsi_ioctl_command
;
39 typedef struct request_queue request_queue_t
;
40 struct elevator_queue
;
41 typedef struct elevator_queue elevator_t
;
42 struct request_pm_state
;
45 #define BLKDEV_MIN_RQ 4
46 #define BLKDEV_MAX_RQ 128 /* Default maximum */
49 * This is the per-process anticipatory I/O scheduler state.
51 struct as_io_context
{
54 void (*dtor
)(struct as_io_context
*aic
); /* destructor */
55 void (*exit
)(struct as_io_context
*aic
); /* called on task exit */
58 atomic_t nr_queued
; /* queued reads & sync writes */
59 atomic_t nr_dispatched
; /* number of requests gone to the drivers */
61 /* IO History tracking */
63 unsigned long last_end_request
;
64 unsigned long ttime_total
;
65 unsigned long ttime_samples
;
66 unsigned long ttime_mean
;
68 unsigned int seek_samples
;
69 sector_t last_request_pos
;
75 struct cfq_io_context
{
76 struct rb_node rb_node
;
79 struct cfq_queue
*cfqq
[2];
81 struct io_context
*ioc
;
83 unsigned long last_end_request
;
84 sector_t last_request_pos
;
85 unsigned long last_queue
;
87 unsigned long ttime_total
;
88 unsigned long ttime_samples
;
89 unsigned long ttime_mean
;
91 unsigned int seek_samples
;
95 struct list_head queue_list
;
97 void (*dtor
)(struct io_context
*); /* destructor */
98 void (*exit
)(struct io_context
*); /* called on task exit */
102 * This is the per-process I/O subsystem state. It is refcounted and
103 * kmalloc'ed. Currently all fields are modified in process io context
104 * (apart from the atomic refcount), so require no locking.
108 struct task_struct
*task
;
110 unsigned int ioprio_changed
;
113 * For request batching
115 unsigned long last_waited
; /* Time last woken after wait for request */
116 int nr_batch_requests
; /* Number of requests left in the batch */
118 struct as_io_context
*aic
;
119 struct rb_root cic_root
;
122 void put_io_context(struct io_context
*ioc
);
123 void exit_io_context(void);
124 struct io_context
*get_io_context(gfp_t gfp_flags
, int node
);
125 void copy_io_context(struct io_context
**pdst
, struct io_context
**psrc
);
126 void swap_io_context(struct io_context
**ioc1
, struct io_context
**ioc2
);
129 typedef void (rq_end_io_fn
)(struct request
*, int);
131 struct request_list
{
136 wait_queue_head_t wait
[2];
140 * request command types
142 enum rq_cmd_type_bits
{
143 REQ_TYPE_FS
= 1, /* fs request */
144 REQ_TYPE_BLOCK_PC
, /* scsi command */
145 REQ_TYPE_SENSE
, /* sense request */
146 REQ_TYPE_PM_SUSPEND
, /* suspend request */
147 REQ_TYPE_PM_RESUME
, /* resume request */
148 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
149 REQ_TYPE_FLUSH
, /* flush request */
150 REQ_TYPE_SPECIAL
, /* driver defined type */
151 REQ_TYPE_LINUX_BLOCK
, /* generic block layer message */
153 * for ATA/ATAPI devices. this really doesn't belong here, ide should
154 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
155 * private REQ_LB opcodes to differentiate what type of request this is
159 REQ_TYPE_ATA_TASKFILE
,
164 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
165 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
168 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
169 * typically to differentiate REQ_TYPE_SPECIAL requests.
174 * just examples for now
176 REQ_LB_OP_EJECT
= 0x40, /* eject request */
177 REQ_LB_OP_FLUSH
= 0x41, /* flush device */
181 * request type modified bits. first three bits match BIO_RW* bits, important
184 __REQ_RW
, /* not set, read. set, write */
185 __REQ_FAILFAST
, /* no low level driver retries */
186 __REQ_SORTED
, /* elevator knows about this request */
187 __REQ_SOFTBARRIER
, /* may not be passed by ioscheduler */
188 __REQ_HARDBARRIER
, /* may not be passed by drive either */
189 __REQ_FUA
, /* forced unit access */
190 __REQ_NOMERGE
, /* don't touch this for merging */
191 __REQ_STARTED
, /* drive already may have started this one */
192 __REQ_DONTPREP
, /* don't call prep for this one */
193 __REQ_QUEUED
, /* uses queueing */
194 __REQ_ELVPRIV
, /* elevator private data attached */
195 __REQ_FAILED
, /* set if the request failed */
196 __REQ_QUIET
, /* don't worry about errors */
197 __REQ_PREEMPT
, /* set for "ide_preempt" requests */
198 __REQ_ORDERED_COLOR
, /* is before or after barrier */
199 __REQ_RW_SYNC
, /* request is sync (O_DIRECT) */
200 __REQ_ALLOCED
, /* request came from our alloc pool */
201 __REQ_RW_META
, /* metadata io request */
202 __REQ_NR_BITS
, /* stops here */
205 #define REQ_RW (1 << __REQ_RW)
206 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
207 #define REQ_SORTED (1 << __REQ_SORTED)
208 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
209 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
210 #define REQ_FUA (1 << __REQ_FUA)
211 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
212 #define REQ_STARTED (1 << __REQ_STARTED)
213 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
214 #define REQ_QUEUED (1 << __REQ_QUEUED)
215 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
216 #define REQ_FAILED (1 << __REQ_FAILED)
217 #define REQ_QUIET (1 << __REQ_QUIET)
218 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
219 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
220 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
221 #define REQ_ALLOCED (1 << __REQ_ALLOCED)
222 #define REQ_RW_META (1 << __REQ_RW_META)
224 #define BLK_MAX_CDB 16
227 * try to put the fields that are referenced together in the same cacheline
230 struct list_head queuelist
;
231 struct list_head donelist
;
235 unsigned int cmd_flags
;
236 enum rq_cmd_type_bits cmd_type
;
238 /* Maintain bio traversal state for part by part I/O submission.
239 * hard_* are block layer internals, no driver should touch them!
242 sector_t sector
; /* next sector to submit */
243 sector_t hard_sector
; /* next sector to complete */
244 unsigned long nr_sectors
; /* no. of sectors left to submit */
245 unsigned long hard_nr_sectors
; /* no. of sectors left to complete */
246 /* no. of sectors left to submit in the current segment */
247 unsigned int current_nr_sectors
;
249 /* no. of sectors left to complete in the current segment */
250 unsigned int hard_cur_sectors
;
255 struct hlist_node hash
; /* merge hash */
257 * The rb_node is only used inside the io scheduler, requests
258 * are pruned when moved to the dispatch queue. So let the
259 * completion_data share space with the rb_node.
262 struct rb_node rb_node
; /* sort/lookup */
263 void *completion_data
;
267 * two pointers are available for the IO schedulers, if they need
268 * more they have to dynamically allocate it.
270 void *elevator_private
;
271 void *elevator_private2
;
273 struct gendisk
*rq_disk
;
274 unsigned long start_time
;
276 /* Number of scatter-gather DMA addr+len pairs after
277 * physical address coalescing is performed.
279 unsigned short nr_phys_segments
;
281 /* Number of scatter-gather addr+len pairs after
282 * physical and DMA remapping hardware coalescing is performed.
283 * This is the number of scatter-gather entries the driver
284 * will actually have to deal with after DMA mapping is done.
286 unsigned short nr_hw_segments
;
288 unsigned short ioprio
;
299 * when request is used as a packet command carrier
301 unsigned int cmd_len
;
302 unsigned char cmd
[BLK_MAX_CDB
];
304 unsigned int data_len
;
305 unsigned int sense_len
;
309 unsigned int timeout
;
313 * completion callback.
315 rq_end_io_fn
*end_io
;
320 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
321 * requests. Some step values could eventually be made generic.
323 struct request_pm_state
325 /* PM state machine step value, currently driver specific */
327 /* requested PM state value (S1, S2, S3, S4, ...) */
329 void* data
; /* for driver use */
332 #include <linux/elevator.h>
334 typedef int (merge_request_fn
) (request_queue_t
*, struct request
*,
336 typedef int (merge_requests_fn
) (request_queue_t
*, struct request
*,
338 typedef void (request_fn_proc
) (request_queue_t
*q
);
339 typedef int (make_request_fn
) (request_queue_t
*q
, struct bio
*bio
);
340 typedef int (prep_rq_fn
) (request_queue_t
*, struct request
*);
341 typedef void (unplug_fn
) (request_queue_t
*);
344 typedef int (merge_bvec_fn
) (request_queue_t
*, struct bio
*, struct bio_vec
*);
345 typedef void (activity_fn
) (void *data
, int rw
);
346 typedef int (issue_flush_fn
) (request_queue_t
*, struct gendisk
*, sector_t
*);
347 typedef void (prepare_flush_fn
) (request_queue_t
*, struct request
*);
348 typedef void (softirq_done_fn
)(struct request
*);
350 enum blk_queue_state
{
355 struct blk_queue_tag
{
356 struct request
**tag_index
; /* map of busy tags */
357 unsigned long *tag_map
; /* bit map of free/busy tags */
358 struct list_head busy_list
; /* fifo list of busy tags */
359 int busy
; /* current depth */
360 int max_depth
; /* what we will send to device */
361 int real_max_depth
; /* what the array can hold */
362 atomic_t refcnt
; /* map can be shared */
368 * Together with queue_head for cacheline sharing
370 struct list_head queue_head
;
371 struct request
*last_merge
;
372 elevator_t
*elevator
;
375 * the queue request freelist, one for reads and one for writes
377 struct request_list rq
;
379 request_fn_proc
*request_fn
;
380 merge_request_fn
*back_merge_fn
;
381 merge_request_fn
*front_merge_fn
;
382 merge_requests_fn
*merge_requests_fn
;
383 make_request_fn
*make_request_fn
;
384 prep_rq_fn
*prep_rq_fn
;
385 unplug_fn
*unplug_fn
;
386 merge_bvec_fn
*merge_bvec_fn
;
387 activity_fn
*activity_fn
;
388 issue_flush_fn
*issue_flush_fn
;
389 prepare_flush_fn
*prepare_flush_fn
;
390 softirq_done_fn
*softirq_done_fn
;
393 * Dispatch queue sorting
396 struct request
*boundary_rq
;
399 * Auto-unplugging state
401 struct timer_list unplug_timer
;
402 int unplug_thresh
; /* After this many requests */
403 unsigned long unplug_delay
; /* After this many jiffies */
404 struct work_struct unplug_work
;
406 struct backing_dev_info backing_dev_info
;
409 * The queue owner gets to use this for whatever they like.
410 * ll_rw_blk doesn't touch it.
417 * queue needs bounce pages for pages above this limit
419 unsigned long bounce_pfn
;
423 * various queue flags, see QUEUE_* below
425 unsigned long queue_flags
;
428 * protects queue structures from reentrancy. ->__queue_lock should
429 * _never_ be used directly, it is queue private. always use
432 spinlock_t __queue_lock
;
433 spinlock_t
*queue_lock
;
443 unsigned long nr_requests
; /* Max # of requests */
444 unsigned int nr_congestion_on
;
445 unsigned int nr_congestion_off
;
446 unsigned int nr_batching
;
448 unsigned int max_sectors
;
449 unsigned int max_hw_sectors
;
450 unsigned short max_phys_segments
;
451 unsigned short max_hw_segments
;
452 unsigned short hardsect_size
;
453 unsigned int max_segment_size
;
455 unsigned long seg_boundary_mask
;
456 unsigned int dma_alignment
;
458 struct blk_queue_tag
*queue_tags
;
460 unsigned int nr_sorted
;
461 unsigned int in_flight
;
466 unsigned int sg_timeout
;
467 unsigned int sg_reserved_size
;
469 #ifdef CONFIG_BLK_DEV_IO_TRACE
470 struct blk_trace
*blk_trace
;
473 * reserved for flush operations
475 unsigned int ordered
, next_ordered
, ordseq
;
476 int orderr
, ordcolor
;
477 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
478 struct request
*orig_bar_rq
;
479 unsigned int bi_size
;
481 struct mutex sysfs_lock
;
484 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
485 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
486 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
487 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
488 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
489 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
490 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
491 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
492 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
496 * Hardbarrier is supported with one of the following methods.
498 * NONE : hardbarrier unsupported
499 * DRAIN : ordering by draining is enough
500 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
501 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
502 * TAG : ordering by tag is enough
503 * TAG_FLUSH : ordering by tag w/ pre and post flushes
504 * TAG_FUA : ordering by tag w/ pre flush and FUA write
506 QUEUE_ORDERED_NONE
= 0x00,
507 QUEUE_ORDERED_DRAIN
= 0x01,
508 QUEUE_ORDERED_TAG
= 0x02,
510 QUEUE_ORDERED_PREFLUSH
= 0x10,
511 QUEUE_ORDERED_POSTFLUSH
= 0x20,
512 QUEUE_ORDERED_FUA
= 0x40,
514 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
515 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
516 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
517 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
518 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
519 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
520 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
521 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
524 * Ordered operation sequence
526 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
527 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
528 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
529 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
530 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
531 QUEUE_ORDSEQ_DONE
= 0x20,
534 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
535 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
536 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
537 #define blk_queue_flushing(q) ((q)->ordseq)
539 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
540 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
541 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
542 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
544 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
545 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
547 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
549 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
550 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
551 #define blk_pm_request(rq) \
552 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
554 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
555 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
556 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
558 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
560 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
563 * We regard a request as sync, if it's a READ or a SYNC write.
565 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
566 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
568 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
571 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
572 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
575 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
578 set_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
580 set_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
583 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
586 clear_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
588 clear_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
593 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
594 * it already be started by driver.
596 #define RQ_NOMERGE_FLAGS \
597 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
598 #define rq_mergeable(rq) \
599 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
602 * q->prep_rq_fn return values
604 #define BLKPREP_OK 0 /* serve it */
605 #define BLKPREP_KILL 1 /* fatal error, kill */
606 #define BLKPREP_DEFER 2 /* leave on queue */
608 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
611 * standard bounce addresses:
613 * BLK_BOUNCE_HIGH : bounce all highmem pages
614 * BLK_BOUNCE_ANY : don't bounce anything
615 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
617 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
618 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
619 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
622 extern int init_emergency_isa_pool(void);
623 extern void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
);
625 static inline int init_emergency_isa_pool(void)
629 static inline void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
)
632 #endif /* CONFIG_MMU */
634 #define rq_for_each_bio(_bio, rq) \
636 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
638 extern int blk_register_queue(struct gendisk
*disk
);
639 extern void blk_unregister_queue(struct gendisk
*disk
);
640 extern void register_disk(struct gendisk
*dev
);
641 extern void generic_make_request(struct bio
*bio
);
642 extern void blk_put_request(struct request
*);
643 extern void __blk_put_request(request_queue_t
*, struct request
*);
644 extern void blk_end_sync_rq(struct request
*rq
, int error
);
645 extern struct request
*blk_get_request(request_queue_t
*, int, gfp_t
);
646 extern void blk_insert_request(request_queue_t
*, struct request
*, int, void *);
647 extern void blk_requeue_request(request_queue_t
*, struct request
*);
648 extern void blk_plug_device(request_queue_t
*);
649 extern int blk_remove_plug(request_queue_t
*);
650 extern void blk_recount_segments(request_queue_t
*, struct bio
*);
651 extern int scsi_cmd_ioctl(struct file
*, struct gendisk
*, unsigned int, void __user
*);
652 extern int sg_scsi_ioctl(struct file
*, struct request_queue
*,
653 struct gendisk
*, struct scsi_ioctl_command __user
*);
654 extern void blk_start_queue(request_queue_t
*q
);
655 extern void blk_stop_queue(request_queue_t
*q
);
656 extern void blk_sync_queue(struct request_queue
*q
);
657 extern void __blk_stop_queue(request_queue_t
*q
);
658 extern void blk_run_queue(request_queue_t
*);
659 extern void blk_start_queueing(request_queue_t
*);
660 extern void blk_queue_activity_fn(request_queue_t
*, activity_fn
*, void *);
661 extern int blk_rq_map_user(request_queue_t
*, struct request
*, void __user
*, unsigned int);
662 extern int blk_rq_unmap_user(struct bio
*, unsigned int);
663 extern int blk_rq_map_kern(request_queue_t
*, struct request
*, void *, unsigned int, gfp_t
);
664 extern int blk_rq_map_user_iov(request_queue_t
*, struct request
*, struct sg_iovec
*, int);
665 extern int blk_execute_rq(request_queue_t
*, struct gendisk
*,
666 struct request
*, int);
667 extern void blk_execute_rq_nowait(request_queue_t
*, struct gendisk
*,
668 struct request
*, int, rq_end_io_fn
*);
670 static inline request_queue_t
*bdev_get_queue(struct block_device
*bdev
)
672 return bdev
->bd_disk
->queue
;
675 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
678 if (bdi
&& bdi
->unplug_io_fn
)
679 bdi
->unplug_io_fn(bdi
, page
);
682 static inline void blk_run_address_space(struct address_space
*mapping
)
685 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
689 * end_request() and friends. Must be called with the request queue spinlock
690 * acquired. All functions called within end_request() _must_be_ atomic.
692 * Several drivers define their own end_request and call
693 * end_that_request_first() and end_that_request_last()
694 * for parts of the original function. This prevents
695 * code duplication in drivers.
697 extern int end_that_request_first(struct request
*, int, int);
698 extern int end_that_request_chunk(struct request
*, int, int);
699 extern void end_that_request_last(struct request
*, int);
700 extern void end_request(struct request
*req
, int uptodate
);
701 extern void blk_complete_request(struct request
*);
704 * end_that_request_first/chunk() takes an uptodate argument. we account
705 * any value <= as an io error. 0 means -EIO for compatability reasons,
706 * any other < 0 value is the direct error type. An uptodate value of
707 * 1 indicates successful io completion
709 #define end_io_error(uptodate) (unlikely((uptodate) <= 0))
711 static inline void blkdev_dequeue_request(struct request
*req
)
713 elv_dequeue_request(req
->q
, req
);
717 * Access functions for manipulating queue properties
719 extern request_queue_t
*blk_init_queue_node(request_fn_proc
*rfn
,
720 spinlock_t
*lock
, int node_id
);
721 extern request_queue_t
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
722 extern void blk_cleanup_queue(request_queue_t
*);
723 extern void blk_queue_make_request(request_queue_t
*, make_request_fn
*);
724 extern void blk_queue_bounce_limit(request_queue_t
*, u64
);
725 extern void blk_queue_max_sectors(request_queue_t
*, unsigned int);
726 extern void blk_queue_max_phys_segments(request_queue_t
*, unsigned short);
727 extern void blk_queue_max_hw_segments(request_queue_t
*, unsigned short);
728 extern void blk_queue_max_segment_size(request_queue_t
*, unsigned int);
729 extern void blk_queue_hardsect_size(request_queue_t
*, unsigned short);
730 extern void blk_queue_stack_limits(request_queue_t
*t
, request_queue_t
*b
);
731 extern void blk_queue_segment_boundary(request_queue_t
*, unsigned long);
732 extern void blk_queue_prep_rq(request_queue_t
*, prep_rq_fn
*pfn
);
733 extern void blk_queue_merge_bvec(request_queue_t
*, merge_bvec_fn
*);
734 extern void blk_queue_dma_alignment(request_queue_t
*, int);
735 extern void blk_queue_softirq_done(request_queue_t
*, softirq_done_fn
*);
736 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
737 extern int blk_queue_ordered(request_queue_t
*, unsigned, prepare_flush_fn
*);
738 extern void blk_queue_issue_flush_fn(request_queue_t
*, issue_flush_fn
*);
739 extern int blk_do_ordered(request_queue_t
*, struct request
**);
740 extern unsigned blk_ordered_cur_seq(request_queue_t
*);
741 extern unsigned blk_ordered_req_seq(struct request
*);
742 extern void blk_ordered_complete_seq(request_queue_t
*, unsigned, int);
744 extern int blk_rq_map_sg(request_queue_t
*, struct request
*, struct scatterlist
*);
745 extern void blk_dump_rq_flags(struct request
*, char *);
746 extern void generic_unplug_device(request_queue_t
*);
747 extern void __generic_unplug_device(request_queue_t
*);
748 extern long nr_blockdev_pages(void);
750 int blk_get_queue(request_queue_t
*);
751 request_queue_t
*blk_alloc_queue(gfp_t
);
752 request_queue_t
*blk_alloc_queue_node(gfp_t
, int);
753 extern void blk_put_queue(request_queue_t
*);
758 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
759 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
760 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
761 extern int blk_queue_start_tag(request_queue_t
*, struct request
*);
762 extern struct request
*blk_queue_find_tag(request_queue_t
*, int);
763 extern void blk_queue_end_tag(request_queue_t
*, struct request
*);
764 extern int blk_queue_init_tags(request_queue_t
*, int, struct blk_queue_tag
*);
765 extern void blk_queue_free_tags(request_queue_t
*);
766 extern int blk_queue_resize_tags(request_queue_t
*, int);
767 extern void blk_queue_invalidate_tags(request_queue_t
*);
768 extern long blk_congestion_wait(int rw
, long timeout
);
769 extern struct blk_queue_tag
*blk_init_tags(int);
770 extern void blk_free_tags(struct blk_queue_tag
*);
771 extern void blk_congestion_end(int rw
);
773 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
776 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
778 return bqt
->tag_index
[tag
];
781 extern void blk_rq_bio_prep(request_queue_t
*, struct request
*, struct bio
*);
782 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
784 #define MAX_PHYS_SEGMENTS 128
785 #define MAX_HW_SEGMENTS 128
786 #define SAFE_MAX_SECTORS 255
787 #define BLK_DEF_MAX_SECTORS 1024
789 #define MAX_SEGMENT_SIZE 65536
791 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
793 static inline int queue_hardsect_size(request_queue_t
*q
)
797 if (q
&& q
->hardsect_size
)
798 retval
= q
->hardsect_size
;
803 static inline int bdev_hardsect_size(struct block_device
*bdev
)
805 return queue_hardsect_size(bdev_get_queue(bdev
));
808 static inline int queue_dma_alignment(request_queue_t
*q
)
812 if (q
&& q
->dma_alignment
)
813 retval
= q
->dma_alignment
;
818 /* assumes size > 256 */
819 static inline unsigned int blksize_bits(unsigned int size
)
821 unsigned int bits
= 8;
825 } while (size
> 256);
829 static inline unsigned int block_size(struct block_device
*bdev
)
831 return bdev
->bd_block_size
;
834 typedef struct {struct page
*v
;} Sector
;
836 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
838 static inline void put_dev_sector(Sector p
)
840 page_cache_release(p
.v
);
844 int kblockd_schedule_work(struct work_struct
*work
);
845 void kblockd_flush(void);
847 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
848 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
849 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
850 MODULE_ALIAS("block-major-" __stringify(major) "-*")
853 #else /* CONFIG_BLOCK */
855 * stubs for when the block layer is configured out
857 #define buffer_heads_over_limit 0
859 static inline long blk_congestion_wait(int rw
, long timeout
)
861 return io_schedule_timeout(timeout
);
864 static inline long nr_blockdev_pages(void)
869 static inline void exit_io_context(void)
873 #endif /* CONFIG_BLOCK */