1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
4 #include <linux/config.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 typedef struct request_queue request_queue_t
;
22 struct elevator_queue
;
23 typedef struct elevator_queue elevator_t
;
24 struct request_pm_state
;
26 #define BLKDEV_MIN_RQ 4
27 #define BLKDEV_MAX_RQ 128 /* Default maximum */
30 * This is the per-process anticipatory I/O scheduler state.
32 struct as_io_context
{
35 void (*dtor
)(struct as_io_context
*aic
); /* destructor */
36 void (*exit
)(struct as_io_context
*aic
); /* called on task exit */
39 atomic_t nr_queued
; /* queued reads & sync writes */
40 atomic_t nr_dispatched
; /* number of requests gone to the drivers */
42 /* IO History tracking */
44 unsigned long last_end_request
;
45 unsigned long ttime_total
;
46 unsigned long ttime_samples
;
47 unsigned long ttime_mean
;
49 unsigned int seek_samples
;
50 sector_t last_request_pos
;
56 struct cfq_io_context
{
58 * circular list of cfq_io_contexts belonging to a process io context
60 struct list_head list
;
61 struct cfq_queue
*cfqq
;
64 struct io_context
*ioc
;
66 unsigned long last_end_request
;
67 unsigned long last_queue
;
68 unsigned long ttime_total
;
69 unsigned long ttime_samples
;
70 unsigned long ttime_mean
;
72 void (*dtor
)(struct cfq_io_context
*);
73 void (*exit
)(struct cfq_io_context
*);
77 * This is the per-process I/O subsystem state. It is refcounted and
78 * kmalloc'ed. Currently all fields are modified in process io context
79 * (apart from the atomic refcount), so require no locking.
83 struct task_struct
*task
;
85 int (*set_ioprio
)(struct io_context
*, unsigned int);
88 * For request batching
90 unsigned long last_waited
; /* Time last woken after wait for request */
91 int nr_batch_requests
; /* Number of requests left in the batch */
93 struct as_io_context
*aic
;
94 struct cfq_io_context
*cic
;
97 void put_io_context(struct io_context
*ioc
);
98 void exit_io_context(void);
99 struct io_context
*current_io_context(gfp_t gfp_flags
);
100 struct io_context
*get_io_context(gfp_t gfp_flags
);
101 void copy_io_context(struct io_context
**pdst
, struct io_context
**psrc
);
102 void swap_io_context(struct io_context
**ioc1
, struct io_context
**ioc2
);
105 typedef void (rq_end_io_fn
)(struct request
*, int);
107 struct request_list
{
112 wait_queue_head_t wait
[2];
115 #define BLK_MAX_CDB 16
118 * try to put the fields that are referenced together in the same cacheline
121 struct list_head queuelist
; /* looking for ->queue? you must _not_
122 * access it directly, use
123 * blkdev_dequeue_request! */
124 unsigned long flags
; /* see REQ_ bits below */
126 /* Maintain bio traversal state for part by part I/O submission.
127 * hard_* are block layer internals, no driver should touch them!
130 sector_t sector
; /* next sector to submit */
131 unsigned long nr_sectors
; /* no. of sectors left to submit */
132 /* no. of sectors left to submit in the current segment */
133 unsigned int current_nr_sectors
;
135 sector_t hard_sector
; /* next sector to complete */
136 unsigned long hard_nr_sectors
; /* no. of sectors left to complete */
137 /* no. of sectors left to complete in the current segment */
138 unsigned int hard_cur_sectors
;
143 void *elevator_private
;
145 unsigned short ioprio
;
147 int rq_status
; /* should split this into a few status bits */
148 struct gendisk
*rq_disk
;
150 unsigned long start_time
;
152 /* Number of scatter-gather DMA addr+len pairs after
153 * physical address coalescing is performed.
155 unsigned short nr_phys_segments
;
157 /* Number of scatter-gather addr+len pairs after
158 * physical and DMA remapping hardware coalescing is performed.
159 * This is the number of scatter-gather entries the driver
160 * will actually have to deal with after DMA mapping is done.
162 unsigned short nr_hw_segments
;
169 struct request_list
*rl
;
171 struct completion
*waiting
;
175 * when request is used as a packet command carrier
177 unsigned int cmd_len
;
178 unsigned char cmd
[BLK_MAX_CDB
];
180 unsigned int data_len
;
183 unsigned int sense_len
;
186 unsigned int timeout
;
190 * For Power Management requests
192 struct request_pm_state
*pm
;
195 * completion callback. end_io_data should be folded in with waiting
197 rq_end_io_fn
*end_io
;
202 * first three bits match BIO_RW* bits, important
205 __REQ_RW
, /* not set, read. set, write */
206 __REQ_FAILFAST
, /* no low level driver retries */
207 __REQ_SORTED
, /* elevator knows about this request */
208 __REQ_SOFTBARRIER
, /* may not be passed by ioscheduler */
209 __REQ_HARDBARRIER
, /* may not be passed by drive either */
210 __REQ_FUA
, /* forced unit access */
211 __REQ_CMD
, /* is a regular fs rw request */
212 __REQ_NOMERGE
, /* don't touch this for merging */
213 __REQ_STARTED
, /* drive already may have started this one */
214 __REQ_DONTPREP
, /* don't call prep for this one */
215 __REQ_QUEUED
, /* uses queueing */
216 __REQ_ELVPRIV
, /* elevator private data attached */
218 * for ATA/ATAPI devices
220 __REQ_PC
, /* packet command (special) */
221 __REQ_BLOCK_PC
, /* queued down pc from block layer */
222 __REQ_SENSE
, /* sense retrival */
224 __REQ_FAILED
, /* set if the request failed */
225 __REQ_QUIET
, /* don't worry about errors */
226 __REQ_SPECIAL
, /* driver suplied command */
229 __REQ_DRIVE_TASKFILE
,
230 __REQ_PREEMPT
, /* set for "ide_preempt" requests */
231 __REQ_PM_SUSPEND
, /* suspend request */
232 __REQ_PM_RESUME
, /* resume request */
233 __REQ_PM_SHUTDOWN
, /* shutdown request */
234 __REQ_ORDERED_COLOR
, /* is before or after barrier */
235 __REQ_NR_BITS
, /* stops here */
238 #define REQ_RW (1 << __REQ_RW)
239 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
240 #define REQ_SORTED (1 << __REQ_SORTED)
241 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
242 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
243 #define REQ_FUA (1 << __REQ_FUA)
244 #define REQ_CMD (1 << __REQ_CMD)
245 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
246 #define REQ_STARTED (1 << __REQ_STARTED)
247 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
248 #define REQ_QUEUED (1 << __REQ_QUEUED)
249 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
250 #define REQ_PC (1 << __REQ_PC)
251 #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
252 #define REQ_SENSE (1 << __REQ_SENSE)
253 #define REQ_FAILED (1 << __REQ_FAILED)
254 #define REQ_QUIET (1 << __REQ_QUIET)
255 #define REQ_SPECIAL (1 << __REQ_SPECIAL)
256 #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
257 #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
258 #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
259 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
260 #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
261 #define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
262 #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
263 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
266 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
267 * requests. Some step values could eventually be made generic.
269 struct request_pm_state
271 /* PM state machine step value, currently driver specific */
273 /* requested PM state value (S1, S2, S3, S4, ...) */
275 void* data
; /* for driver use */
278 #include <linux/elevator.h>
280 typedef int (merge_request_fn
) (request_queue_t
*, struct request
*,
282 typedef int (merge_requests_fn
) (request_queue_t
*, struct request
*,
284 typedef void (request_fn_proc
) (request_queue_t
*q
);
285 typedef int (make_request_fn
) (request_queue_t
*q
, struct bio
*bio
);
286 typedef int (prep_rq_fn
) (request_queue_t
*, struct request
*);
287 typedef void (unplug_fn
) (request_queue_t
*);
290 typedef int (merge_bvec_fn
) (request_queue_t
*, struct bio
*, struct bio_vec
*);
291 typedef void (activity_fn
) (void *data
, int rw
);
292 typedef int (issue_flush_fn
) (request_queue_t
*, struct gendisk
*, sector_t
*);
293 typedef void (prepare_flush_fn
) (request_queue_t
*, struct request
*);
295 enum blk_queue_state
{
300 struct blk_queue_tag
{
301 struct request
**tag_index
; /* map of busy tags */
302 unsigned long *tag_map
; /* bit map of free/busy tags */
303 struct list_head busy_list
; /* fifo list of busy tags */
304 int busy
; /* current depth */
305 int max_depth
; /* what we will send to device */
306 int real_max_depth
; /* what the array can hold */
307 atomic_t refcnt
; /* map can be shared */
313 * Together with queue_head for cacheline sharing
315 struct list_head queue_head
;
316 struct request
*last_merge
;
317 elevator_t
*elevator
;
320 * the queue request freelist, one for reads and one for writes
322 struct request_list rq
;
324 request_fn_proc
*request_fn
;
325 merge_request_fn
*back_merge_fn
;
326 merge_request_fn
*front_merge_fn
;
327 merge_requests_fn
*merge_requests_fn
;
328 make_request_fn
*make_request_fn
;
329 prep_rq_fn
*prep_rq_fn
;
330 unplug_fn
*unplug_fn
;
331 merge_bvec_fn
*merge_bvec_fn
;
332 activity_fn
*activity_fn
;
333 issue_flush_fn
*issue_flush_fn
;
334 prepare_flush_fn
*prepare_flush_fn
;
337 * Dispatch queue sorting
340 struct request
*boundary_rq
;
343 * Auto-unplugging state
345 struct timer_list unplug_timer
;
346 int unplug_thresh
; /* After this many requests */
347 unsigned long unplug_delay
; /* After this many jiffies */
348 struct work_struct unplug_work
;
350 struct backing_dev_info backing_dev_info
;
353 * The queue owner gets to use this for whatever they like.
354 * ll_rw_blk doesn't touch it.
361 * queue needs bounce pages for pages above this limit
363 unsigned long bounce_pfn
;
367 * various queue flags, see QUEUE_* below
369 unsigned long queue_flags
;
372 * protects queue structures from reentrancy. ->__queue_lock should
373 * _never_ be used directly, it is queue private. always use
376 spinlock_t __queue_lock
;
377 spinlock_t
*queue_lock
;
387 unsigned long nr_requests
; /* Max # of requests */
388 unsigned int nr_congestion_on
;
389 unsigned int nr_congestion_off
;
390 unsigned int nr_batching
;
392 unsigned short max_sectors
;
393 unsigned short max_hw_sectors
;
394 unsigned short max_phys_segments
;
395 unsigned short max_hw_segments
;
396 unsigned short hardsect_size
;
397 unsigned int max_segment_size
;
399 unsigned long seg_boundary_mask
;
400 unsigned int dma_alignment
;
402 struct blk_queue_tag
*queue_tags
;
406 unsigned int nr_sorted
;
407 unsigned int in_flight
;
412 unsigned int sg_timeout
;
413 unsigned int sg_reserved_size
;
417 * reserved for flush operations
419 unsigned int ordered
, next_ordered
, ordseq
;
420 int orderr
, ordcolor
;
421 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
422 struct request
*orig_bar_rq
;
423 unsigned int bi_size
;
426 #define RQ_INACTIVE (-1)
428 #define RQ_SCSI_BUSY 0xffff
429 #define RQ_SCSI_DONE 0xfffe
430 #define RQ_SCSI_DISCONNECTING 0xffe0
432 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
433 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
434 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
435 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
436 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
437 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
438 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
439 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
440 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
444 * Hardbarrier is supported with one of the following methods.
446 * NONE : hardbarrier unsupported
447 * DRAIN : ordering by draining is enough
448 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
449 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
450 * TAG : ordering by tag is enough
451 * TAG_FLUSH : ordering by tag w/ pre and post flushes
452 * TAG_FUA : ordering by tag w/ pre flush and FUA write
454 QUEUE_ORDERED_NONE
= 0x00,
455 QUEUE_ORDERED_DRAIN
= 0x01,
456 QUEUE_ORDERED_TAG
= 0x02,
458 QUEUE_ORDERED_PREFLUSH
= 0x10,
459 QUEUE_ORDERED_POSTFLUSH
= 0x20,
460 QUEUE_ORDERED_FUA
= 0x40,
462 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
463 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
464 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
465 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
466 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
467 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
468 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
469 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
472 * Ordered operation sequence
474 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
475 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
476 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
477 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
478 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
479 QUEUE_ORDSEQ_DONE
= 0x20,
482 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
483 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
484 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
485 #define blk_queue_flushing(q) ((q)->ordseq)
487 #define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
488 #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
489 #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
490 #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
492 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
494 #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
495 #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
496 #define blk_pm_request(rq) \
497 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
499 #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
500 #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
501 #define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
503 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
505 #define rq_data_dir(rq) ((rq)->flags & 1)
507 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
510 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
511 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
514 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
517 set_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
519 set_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
522 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
525 clear_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
527 clear_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
532 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
533 * it already be started by driver.
535 #define RQ_NOMERGE_FLAGS \
536 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
537 #define rq_mergeable(rq) \
538 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
541 * noop, requests are automagically marked as active/inactive by I/O
542 * scheduler -- see elv_next_request
544 #define blk_queue_headactive(q, head_active)
547 * q->prep_rq_fn return values
549 #define BLKPREP_OK 0 /* serve it */
550 #define BLKPREP_KILL 1 /* fatal error, kill */
551 #define BLKPREP_DEFER 2 /* leave on queue */
553 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
556 * standard bounce addresses:
558 * BLK_BOUNCE_HIGH : bounce all highmem pages
559 * BLK_BOUNCE_ANY : don't bounce anything
560 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
562 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
563 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
564 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
567 extern int init_emergency_isa_pool(void);
568 extern void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
);
570 static inline int init_emergency_isa_pool(void)
574 static inline void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
)
577 #endif /* CONFIG_MMU */
579 #define rq_for_each_bio(_bio, rq) \
581 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
585 unsigned block_size_bits
;
588 extern int blk_register_queue(struct gendisk
*disk
);
589 extern void blk_unregister_queue(struct gendisk
*disk
);
590 extern void register_disk(struct gendisk
*dev
);
591 extern void generic_make_request(struct bio
*bio
);
592 extern void blk_put_request(struct request
*);
593 extern void __blk_put_request(request_queue_t
*, struct request
*);
594 extern void blk_end_sync_rq(struct request
*rq
, int error
);
595 extern void blk_attempt_remerge(request_queue_t
*, struct request
*);
596 extern struct request
*blk_get_request(request_queue_t
*, int, gfp_t
);
597 extern void blk_insert_request(request_queue_t
*, struct request
*, int, void *);
598 extern void blk_requeue_request(request_queue_t
*, struct request
*);
599 extern void blk_plug_device(request_queue_t
*);
600 extern int blk_remove_plug(request_queue_t
*);
601 extern void blk_recount_segments(request_queue_t
*, struct bio
*);
602 extern int scsi_cmd_ioctl(struct file
*, struct gendisk
*, unsigned int, void __user
*);
603 extern void blk_start_queue(request_queue_t
*q
);
604 extern void blk_stop_queue(request_queue_t
*q
);
605 extern void blk_sync_queue(struct request_queue
*q
);
606 extern void __blk_stop_queue(request_queue_t
*q
);
607 extern void blk_run_queue(request_queue_t
*);
608 extern void blk_queue_activity_fn(request_queue_t
*, activity_fn
*, void *);
609 extern int blk_rq_map_user(request_queue_t
*, struct request
*, void __user
*, unsigned int);
610 extern int blk_rq_unmap_user(struct bio
*, unsigned int);
611 extern int blk_rq_map_kern(request_queue_t
*, struct request
*, void *, unsigned int, gfp_t
);
612 extern int blk_rq_map_user_iov(request_queue_t
*, struct request
*, struct sg_iovec
*, int);
613 extern int blk_execute_rq(request_queue_t
*, struct gendisk
*,
614 struct request
*, int);
615 extern void blk_execute_rq_nowait(request_queue_t
*, struct gendisk
*,
616 struct request
*, int, rq_end_io_fn
*);
618 static inline request_queue_t
*bdev_get_queue(struct block_device
*bdev
)
620 return bdev
->bd_disk
->queue
;
623 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
626 if (bdi
&& bdi
->unplug_io_fn
)
627 bdi
->unplug_io_fn(bdi
, page
);
630 static inline void blk_run_address_space(struct address_space
*mapping
)
633 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
637 * end_request() and friends. Must be called with the request queue spinlock
638 * acquired. All functions called within end_request() _must_be_ atomic.
640 * Several drivers define their own end_request and call
641 * end_that_request_first() and end_that_request_last()
642 * for parts of the original function. This prevents
643 * code duplication in drivers.
645 extern int end_that_request_first(struct request
*, int, int);
646 extern int end_that_request_chunk(struct request
*, int, int);
647 extern void end_that_request_last(struct request
*, int);
648 extern void end_request(struct request
*req
, int uptodate
);
651 * end_that_request_first/chunk() takes an uptodate argument. we account
652 * any value <= as an io error. 0 means -EIO for compatability reasons,
653 * any other < 0 value is the direct error type. An uptodate value of
654 * 1 indicates successful io completion
656 #define end_io_error(uptodate) (unlikely((uptodate) <= 0))
658 static inline void blkdev_dequeue_request(struct request
*req
)
660 elv_dequeue_request(req
->q
, req
);
664 * This should be in elevator.h, but that requires pulling in rq and q
666 static inline void elv_dispatch_add_tail(struct request_queue
*q
,
669 if (q
->last_merge
== rq
)
670 q
->last_merge
= NULL
;
673 q
->end_sector
= rq_end_sector(rq
);
675 list_add_tail(&rq
->queuelist
, &q
->queue_head
);
679 * Access functions for manipulating queue properties
681 extern request_queue_t
*blk_init_queue_node(request_fn_proc
*rfn
,
682 spinlock_t
*lock
, int node_id
);
683 extern request_queue_t
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
684 extern void blk_cleanup_queue(request_queue_t
*);
685 extern void blk_queue_make_request(request_queue_t
*, make_request_fn
*);
686 extern void blk_queue_bounce_limit(request_queue_t
*, u64
);
687 extern void blk_queue_max_sectors(request_queue_t
*, unsigned short);
688 extern void blk_queue_max_phys_segments(request_queue_t
*, unsigned short);
689 extern void blk_queue_max_hw_segments(request_queue_t
*, unsigned short);
690 extern void blk_queue_max_segment_size(request_queue_t
*, unsigned int);
691 extern void blk_queue_hardsect_size(request_queue_t
*, unsigned short);
692 extern void blk_queue_stack_limits(request_queue_t
*t
, request_queue_t
*b
);
693 extern void blk_queue_segment_boundary(request_queue_t
*, unsigned long);
694 extern void blk_queue_prep_rq(request_queue_t
*, prep_rq_fn
*pfn
);
695 extern void blk_queue_merge_bvec(request_queue_t
*, merge_bvec_fn
*);
696 extern void blk_queue_dma_alignment(request_queue_t
*, int);
697 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
698 extern int blk_queue_ordered(request_queue_t
*, unsigned, prepare_flush_fn
*);
699 extern void blk_queue_issue_flush_fn(request_queue_t
*, issue_flush_fn
*);
700 extern int blk_do_ordered(request_queue_t
*, struct request
**);
701 extern unsigned blk_ordered_cur_seq(request_queue_t
*);
702 extern unsigned blk_ordered_req_seq(struct request
*);
703 extern void blk_ordered_complete_seq(request_queue_t
*, unsigned, int);
705 extern int blk_rq_map_sg(request_queue_t
*, struct request
*, struct scatterlist
*);
706 extern void blk_dump_rq_flags(struct request
*, char *);
707 extern void generic_unplug_device(request_queue_t
*);
708 extern void __generic_unplug_device(request_queue_t
*);
709 extern long nr_blockdev_pages(void);
711 int blk_get_queue(request_queue_t
*);
712 request_queue_t
*blk_alloc_queue(gfp_t
);
713 request_queue_t
*blk_alloc_queue_node(gfp_t
, int);
714 #define blk_put_queue(q) blk_cleanup_queue((q))
719 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
720 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
721 #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
722 extern int blk_queue_start_tag(request_queue_t
*, struct request
*);
723 extern struct request
*blk_queue_find_tag(request_queue_t
*, int);
724 extern void blk_queue_end_tag(request_queue_t
*, struct request
*);
725 extern int blk_queue_init_tags(request_queue_t
*, int, struct blk_queue_tag
*);
726 extern void blk_queue_free_tags(request_queue_t
*);
727 extern int blk_queue_resize_tags(request_queue_t
*, int);
728 extern void blk_queue_invalidate_tags(request_queue_t
*);
729 extern long blk_congestion_wait(int rw
, long timeout
);
731 extern void blk_rq_bio_prep(request_queue_t
*, struct request
*, struct bio
*);
732 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
734 #define MAX_PHYS_SEGMENTS 128
735 #define MAX_HW_SEGMENTS 128
736 #define SAFE_MAX_SECTORS 255
737 #define BLK_DEF_MAX_SECTORS 1024
739 #define MAX_SEGMENT_SIZE 65536
741 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
743 static inline int queue_hardsect_size(request_queue_t
*q
)
747 if (q
&& q
->hardsect_size
)
748 retval
= q
->hardsect_size
;
753 static inline int bdev_hardsect_size(struct block_device
*bdev
)
755 return queue_hardsect_size(bdev_get_queue(bdev
));
758 static inline int queue_dma_alignment(request_queue_t
*q
)
762 if (q
&& q
->dma_alignment
)
763 retval
= q
->dma_alignment
;
768 static inline int bdev_dma_aligment(struct block_device
*bdev
)
770 return queue_dma_alignment(bdev_get_queue(bdev
));
773 #define blk_finished_io(nsects) do { } while (0)
774 #define blk_started_io(nsects) do { } while (0)
776 /* assumes size > 256 */
777 static inline unsigned int blksize_bits(unsigned int size
)
779 unsigned int bits
= 8;
783 } while (size
> 256);
787 static inline unsigned int block_size(struct block_device
*bdev
)
789 return bdev
->bd_block_size
;
792 typedef struct {struct page
*v
;} Sector
;
794 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
796 static inline void put_dev_sector(Sector p
)
798 page_cache_release(p
.v
);
802 int kblockd_schedule_work(struct work_struct
*work
);
803 void kblockd_flush(void);
806 # include <asm/div64.h>
807 # define sector_div(a, b) do_div(a, b)
809 # define sector_div(n, b)( \
819 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
820 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
821 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
822 MODULE_ALIAS("block-major-" __stringify(major) "-*")