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
;
27 #define BLKDEV_MIN_RQ 4
28 #define BLKDEV_MAX_RQ 128 /* Default maximum */
31 * This is the per-process anticipatory I/O scheduler state.
33 struct as_io_context
{
36 void (*dtor
)(struct as_io_context
*aic
); /* destructor */
37 void (*exit
)(struct as_io_context
*aic
); /* called on task exit */
40 atomic_t nr_queued
; /* queued reads & sync writes */
41 atomic_t nr_dispatched
; /* number of requests gone to the drivers */
43 /* IO History tracking */
45 unsigned long last_end_request
;
46 unsigned long ttime_total
;
47 unsigned long ttime_samples
;
48 unsigned long ttime_mean
;
50 unsigned int seek_samples
;
51 sector_t last_request_pos
;
57 struct cfq_io_context
{
59 * circular list of cfq_io_contexts belonging to a process io context
61 struct list_head list
;
62 struct cfq_queue
*cfqq
[2];
65 struct io_context
*ioc
;
67 unsigned long last_end_request
;
68 unsigned long last_queue
;
69 unsigned long ttime_total
;
70 unsigned long ttime_samples
;
71 unsigned long ttime_mean
;
73 struct list_head queue_list
;
75 void (*dtor
)(struct cfq_io_context
*);
76 void (*exit
)(struct cfq_io_context
*);
80 * This is the per-process I/O subsystem state. It is refcounted and
81 * kmalloc'ed. Currently all fields are modified in process io context
82 * (apart from the atomic refcount), so require no locking.
86 struct task_struct
*task
;
88 int (*set_ioprio
)(struct io_context
*, unsigned int);
91 * For request batching
93 unsigned long last_waited
; /* Time last woken after wait for request */
94 int nr_batch_requests
; /* Number of requests left in the batch */
96 struct as_io_context
*aic
;
97 struct cfq_io_context
*cic
;
100 void put_io_context(struct io_context
*ioc
);
101 void exit_io_context(void);
102 struct io_context
*current_io_context(gfp_t gfp_flags
);
103 struct io_context
*get_io_context(gfp_t gfp_flags
);
104 void copy_io_context(struct io_context
**pdst
, struct io_context
**psrc
);
105 void swap_io_context(struct io_context
**ioc1
, struct io_context
**ioc2
);
108 typedef void (rq_end_io_fn
)(struct request
*, int);
110 struct request_list
{
115 wait_queue_head_t wait
[2];
118 #define BLK_MAX_CDB 16
121 * try to put the fields that are referenced together in the same cacheline
124 struct list_head queuelist
;
125 struct list_head donelist
;
127 unsigned long flags
; /* see REQ_ bits below */
129 /* Maintain bio traversal state for part by part I/O submission.
130 * hard_* are block layer internals, no driver should touch them!
133 sector_t sector
; /* next sector to submit */
134 unsigned long nr_sectors
; /* no. of sectors left to submit */
135 /* no. of sectors left to submit in the current segment */
136 unsigned int current_nr_sectors
;
138 sector_t hard_sector
; /* next sector to complete */
139 unsigned long hard_nr_sectors
; /* no. of sectors left to complete */
140 /* no. of sectors left to complete in the current segment */
141 unsigned int hard_cur_sectors
;
146 void *elevator_private
;
147 void *completion_data
;
149 unsigned short ioprio
;
151 int rq_status
; /* should split this into a few status bits */
152 struct gendisk
*rq_disk
;
154 unsigned long start_time
;
156 /* Number of scatter-gather DMA addr+len pairs after
157 * physical address coalescing is performed.
159 unsigned short nr_phys_segments
;
161 /* Number of scatter-gather addr+len pairs after
162 * physical and DMA remapping hardware coalescing is performed.
163 * This is the number of scatter-gather entries the driver
164 * will actually have to deal with after DMA mapping is done.
166 unsigned short nr_hw_segments
;
173 struct request_list
*rl
;
175 struct completion
*waiting
;
179 * when request is used as a packet command carrier
181 unsigned int cmd_len
;
182 unsigned char cmd
[BLK_MAX_CDB
];
184 unsigned int data_len
;
187 unsigned int sense_len
;
190 unsigned int timeout
;
194 * For Power Management requests
196 struct request_pm_state
*pm
;
199 * completion callback. end_io_data should be folded in with waiting
201 rq_end_io_fn
*end_io
;
206 * first three bits match BIO_RW* bits, important
209 __REQ_RW
, /* not set, read. set, write */
210 __REQ_FAILFAST
, /* no low level driver retries */
211 __REQ_SORTED
, /* elevator knows about this request */
212 __REQ_SOFTBARRIER
, /* may not be passed by ioscheduler */
213 __REQ_HARDBARRIER
, /* may not be passed by drive either */
214 __REQ_FUA
, /* forced unit access */
215 __REQ_CMD
, /* is a regular fs rw request */
216 __REQ_NOMERGE
, /* don't touch this for merging */
217 __REQ_STARTED
, /* drive already may have started this one */
218 __REQ_DONTPREP
, /* don't call prep for this one */
219 __REQ_QUEUED
, /* uses queueing */
220 __REQ_ELVPRIV
, /* elevator private data attached */
222 * for ATA/ATAPI devices
224 __REQ_PC
, /* packet command (special) */
225 __REQ_BLOCK_PC
, /* queued down pc from block layer */
226 __REQ_SENSE
, /* sense retrival */
228 __REQ_FAILED
, /* set if the request failed */
229 __REQ_QUIET
, /* don't worry about errors */
230 __REQ_SPECIAL
, /* driver suplied command */
233 __REQ_DRIVE_TASKFILE
,
234 __REQ_PREEMPT
, /* set for "ide_preempt" requests */
235 __REQ_PM_SUSPEND
, /* suspend request */
236 __REQ_PM_RESUME
, /* resume request */
237 __REQ_PM_SHUTDOWN
, /* shutdown request */
238 __REQ_ORDERED_COLOR
, /* is before or after barrier */
239 __REQ_NR_BITS
, /* stops here */
242 #define REQ_RW (1 << __REQ_RW)
243 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
244 #define REQ_SORTED (1 << __REQ_SORTED)
245 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
246 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
247 #define REQ_FUA (1 << __REQ_FUA)
248 #define REQ_CMD (1 << __REQ_CMD)
249 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
250 #define REQ_STARTED (1 << __REQ_STARTED)
251 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
252 #define REQ_QUEUED (1 << __REQ_QUEUED)
253 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
254 #define REQ_PC (1 << __REQ_PC)
255 #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
256 #define REQ_SENSE (1 << __REQ_SENSE)
257 #define REQ_FAILED (1 << __REQ_FAILED)
258 #define REQ_QUIET (1 << __REQ_QUIET)
259 #define REQ_SPECIAL (1 << __REQ_SPECIAL)
260 #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
261 #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
262 #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
263 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
264 #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
265 #define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
266 #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
267 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
270 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
271 * requests. Some step values could eventually be made generic.
273 struct request_pm_state
275 /* PM state machine step value, currently driver specific */
277 /* requested PM state value (S1, S2, S3, S4, ...) */
279 void* data
; /* for driver use */
282 #include <linux/elevator.h>
284 typedef int (merge_request_fn
) (request_queue_t
*, struct request
*,
286 typedef int (merge_requests_fn
) (request_queue_t
*, struct request
*,
288 typedef void (request_fn_proc
) (request_queue_t
*q
);
289 typedef int (make_request_fn
) (request_queue_t
*q
, struct bio
*bio
);
290 typedef int (prep_rq_fn
) (request_queue_t
*, struct request
*);
291 typedef void (unplug_fn
) (request_queue_t
*);
294 typedef int (merge_bvec_fn
) (request_queue_t
*, struct bio
*, struct bio_vec
*);
295 typedef void (activity_fn
) (void *data
, int rw
);
296 typedef int (issue_flush_fn
) (request_queue_t
*, struct gendisk
*, sector_t
*);
297 typedef void (prepare_flush_fn
) (request_queue_t
*, struct request
*);
298 typedef void (softirq_done_fn
)(struct request
*);
300 enum blk_queue_state
{
305 struct blk_queue_tag
{
306 struct request
**tag_index
; /* map of busy tags */
307 unsigned long *tag_map
; /* bit map of free/busy tags */
308 struct list_head busy_list
; /* fifo list of busy tags */
309 int busy
; /* current depth */
310 int max_depth
; /* what we will send to device */
311 int real_max_depth
; /* what the array can hold */
312 atomic_t refcnt
; /* map can be shared */
318 * Together with queue_head for cacheline sharing
320 struct list_head queue_head
;
321 struct request
*last_merge
;
322 elevator_t
*elevator
;
325 * the queue request freelist, one for reads and one for writes
327 struct request_list rq
;
329 request_fn_proc
*request_fn
;
330 merge_request_fn
*back_merge_fn
;
331 merge_request_fn
*front_merge_fn
;
332 merge_requests_fn
*merge_requests_fn
;
333 make_request_fn
*make_request_fn
;
334 prep_rq_fn
*prep_rq_fn
;
335 unplug_fn
*unplug_fn
;
336 merge_bvec_fn
*merge_bvec_fn
;
337 activity_fn
*activity_fn
;
338 issue_flush_fn
*issue_flush_fn
;
339 prepare_flush_fn
*prepare_flush_fn
;
340 softirq_done_fn
*softirq_done_fn
;
343 * Dispatch queue sorting
346 struct request
*boundary_rq
;
349 * Auto-unplugging state
351 struct timer_list unplug_timer
;
352 int unplug_thresh
; /* After this many requests */
353 unsigned long unplug_delay
; /* After this many jiffies */
354 struct work_struct unplug_work
;
356 struct backing_dev_info backing_dev_info
;
359 * The queue owner gets to use this for whatever they like.
360 * ll_rw_blk doesn't touch it.
367 * queue needs bounce pages for pages above this limit
369 unsigned long bounce_pfn
;
373 * various queue flags, see QUEUE_* below
375 unsigned long queue_flags
;
378 * protects queue structures from reentrancy. ->__queue_lock should
379 * _never_ be used directly, it is queue private. always use
382 spinlock_t __queue_lock
;
383 spinlock_t
*queue_lock
;
393 unsigned long nr_requests
; /* Max # of requests */
394 unsigned int nr_congestion_on
;
395 unsigned int nr_congestion_off
;
396 unsigned int nr_batching
;
398 unsigned int max_sectors
;
399 unsigned int max_hw_sectors
;
400 unsigned short max_phys_segments
;
401 unsigned short max_hw_segments
;
402 unsigned short hardsect_size
;
403 unsigned int max_segment_size
;
405 unsigned long seg_boundary_mask
;
406 unsigned int dma_alignment
;
408 struct blk_queue_tag
*queue_tags
;
410 unsigned int nr_sorted
;
411 unsigned int in_flight
;
416 unsigned int sg_timeout
;
417 unsigned int sg_reserved_size
;
420 struct blk_trace
*blk_trace
;
423 * reserved for flush operations
425 unsigned int ordered
, next_ordered
, ordseq
;
426 int orderr
, ordcolor
;
427 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
428 struct request
*orig_bar_rq
;
429 unsigned int bi_size
;
431 struct mutex sysfs_lock
;
434 #define RQ_INACTIVE (-1)
436 #define RQ_SCSI_BUSY 0xffff
437 #define RQ_SCSI_DONE 0xfffe
438 #define RQ_SCSI_DISCONNECTING 0xffe0
440 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
441 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
442 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
443 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
444 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
445 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
446 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
447 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
448 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
452 * Hardbarrier is supported with one of the following methods.
454 * NONE : hardbarrier unsupported
455 * DRAIN : ordering by draining is enough
456 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
457 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
458 * TAG : ordering by tag is enough
459 * TAG_FLUSH : ordering by tag w/ pre and post flushes
460 * TAG_FUA : ordering by tag w/ pre flush and FUA write
462 QUEUE_ORDERED_NONE
= 0x00,
463 QUEUE_ORDERED_DRAIN
= 0x01,
464 QUEUE_ORDERED_TAG
= 0x02,
466 QUEUE_ORDERED_PREFLUSH
= 0x10,
467 QUEUE_ORDERED_POSTFLUSH
= 0x20,
468 QUEUE_ORDERED_FUA
= 0x40,
470 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
471 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
472 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
473 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
474 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
475 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
476 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
477 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
480 * Ordered operation sequence
482 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
483 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
484 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
485 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
486 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
487 QUEUE_ORDSEQ_DONE
= 0x20,
490 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
491 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
492 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
493 #define blk_queue_flushing(q) ((q)->ordseq)
495 #define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
496 #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
497 #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
498 #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
500 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
502 #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
503 #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
504 #define blk_pm_request(rq) \
505 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
507 #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
508 #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
509 #define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
511 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
513 #define rq_data_dir(rq) ((rq)->flags & 1)
515 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
518 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
519 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
522 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
525 set_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
527 set_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
530 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
533 clear_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
535 clear_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
540 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
541 * it already be started by driver.
543 #define RQ_NOMERGE_FLAGS \
544 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
545 #define rq_mergeable(rq) \
546 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
549 * noop, requests are automagically marked as active/inactive by I/O
550 * scheduler -- see elv_next_request
552 #define blk_queue_headactive(q, head_active)
555 * q->prep_rq_fn return values
557 #define BLKPREP_OK 0 /* serve it */
558 #define BLKPREP_KILL 1 /* fatal error, kill */
559 #define BLKPREP_DEFER 2 /* leave on queue */
561 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
564 * standard bounce addresses:
566 * BLK_BOUNCE_HIGH : bounce all highmem pages
567 * BLK_BOUNCE_ANY : don't bounce anything
568 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
570 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
571 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
572 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
575 extern int init_emergency_isa_pool(void);
576 extern void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
);
578 static inline int init_emergency_isa_pool(void)
582 static inline void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
)
585 #endif /* CONFIG_MMU */
587 #define rq_for_each_bio(_bio, rq) \
589 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
593 unsigned block_size_bits
;
596 extern int blk_register_queue(struct gendisk
*disk
);
597 extern void blk_unregister_queue(struct gendisk
*disk
);
598 extern void register_disk(struct gendisk
*dev
);
599 extern void generic_make_request(struct bio
*bio
);
600 extern void blk_put_request(struct request
*);
601 extern void __blk_put_request(request_queue_t
*, struct request
*);
602 extern void blk_end_sync_rq(struct request
*rq
, int error
);
603 extern struct request
*blk_get_request(request_queue_t
*, int, gfp_t
);
604 extern void blk_insert_request(request_queue_t
*, struct request
*, int, void *);
605 extern void blk_requeue_request(request_queue_t
*, struct request
*);
606 extern void blk_plug_device(request_queue_t
*);
607 extern int blk_remove_plug(request_queue_t
*);
608 extern void blk_recount_segments(request_queue_t
*, struct bio
*);
609 extern int scsi_cmd_ioctl(struct file
*, struct gendisk
*, unsigned int, void __user
*);
610 extern void blk_start_queue(request_queue_t
*q
);
611 extern void blk_stop_queue(request_queue_t
*q
);
612 extern void blk_sync_queue(struct request_queue
*q
);
613 extern void __blk_stop_queue(request_queue_t
*q
);
614 extern void blk_run_queue(request_queue_t
*);
615 extern void blk_queue_activity_fn(request_queue_t
*, activity_fn
*, void *);
616 extern int blk_rq_map_user(request_queue_t
*, struct request
*, void __user
*, unsigned int);
617 extern int blk_rq_unmap_user(struct bio
*, unsigned int);
618 extern int blk_rq_map_kern(request_queue_t
*, struct request
*, void *, unsigned int, gfp_t
);
619 extern int blk_rq_map_user_iov(request_queue_t
*, struct request
*, struct sg_iovec
*, int);
620 extern int blk_execute_rq(request_queue_t
*, struct gendisk
*,
621 struct request
*, int);
622 extern void blk_execute_rq_nowait(request_queue_t
*, struct gendisk
*,
623 struct request
*, int, rq_end_io_fn
*);
625 static inline request_queue_t
*bdev_get_queue(struct block_device
*bdev
)
627 return bdev
->bd_disk
->queue
;
630 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
633 if (bdi
&& bdi
->unplug_io_fn
)
634 bdi
->unplug_io_fn(bdi
, page
);
637 static inline void blk_run_address_space(struct address_space
*mapping
)
640 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
644 * end_request() and friends. Must be called with the request queue spinlock
645 * acquired. All functions called within end_request() _must_be_ atomic.
647 * Several drivers define their own end_request and call
648 * end_that_request_first() and end_that_request_last()
649 * for parts of the original function. This prevents
650 * code duplication in drivers.
652 extern int end_that_request_first(struct request
*, int, int);
653 extern int end_that_request_chunk(struct request
*, int, int);
654 extern void end_that_request_last(struct request
*, int);
655 extern void end_request(struct request
*req
, int uptodate
);
656 extern void blk_complete_request(struct request
*);
658 static inline int rq_all_done(struct request
*rq
, unsigned int nr_bytes
)
660 if (blk_fs_request(rq
))
661 return (nr_bytes
>= (rq
->hard_nr_sectors
<< 9));
662 else if (blk_pc_request(rq
))
663 return nr_bytes
>= rq
->data_len
;
669 * end_that_request_first/chunk() takes an uptodate argument. we account
670 * any value <= as an io error. 0 means -EIO for compatability reasons,
671 * any other < 0 value is the direct error type. An uptodate value of
672 * 1 indicates successful io completion
674 #define end_io_error(uptodate) (unlikely((uptodate) <= 0))
676 static inline void blkdev_dequeue_request(struct request
*req
)
678 elv_dequeue_request(req
->q
, req
);
682 * This should be in elevator.h, but that requires pulling in rq and q
684 static inline void elv_dispatch_add_tail(struct request_queue
*q
,
687 if (q
->last_merge
== rq
)
688 q
->last_merge
= NULL
;
691 q
->end_sector
= rq_end_sector(rq
);
693 list_add_tail(&rq
->queuelist
, &q
->queue_head
);
697 * Access functions for manipulating queue properties
699 extern request_queue_t
*blk_init_queue_node(request_fn_proc
*rfn
,
700 spinlock_t
*lock
, int node_id
);
701 extern request_queue_t
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
702 extern void blk_cleanup_queue(request_queue_t
*);
703 extern void blk_queue_make_request(request_queue_t
*, make_request_fn
*);
704 extern void blk_queue_bounce_limit(request_queue_t
*, u64
);
705 extern void blk_queue_max_sectors(request_queue_t
*, unsigned int);
706 extern void blk_queue_max_phys_segments(request_queue_t
*, unsigned short);
707 extern void blk_queue_max_hw_segments(request_queue_t
*, unsigned short);
708 extern void blk_queue_max_segment_size(request_queue_t
*, unsigned int);
709 extern void blk_queue_hardsect_size(request_queue_t
*, unsigned short);
710 extern void blk_queue_stack_limits(request_queue_t
*t
, request_queue_t
*b
);
711 extern void blk_queue_segment_boundary(request_queue_t
*, unsigned long);
712 extern void blk_queue_prep_rq(request_queue_t
*, prep_rq_fn
*pfn
);
713 extern void blk_queue_merge_bvec(request_queue_t
*, merge_bvec_fn
*);
714 extern void blk_queue_dma_alignment(request_queue_t
*, int);
715 extern void blk_queue_softirq_done(request_queue_t
*, softirq_done_fn
*);
716 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
717 extern int blk_queue_ordered(request_queue_t
*, unsigned, prepare_flush_fn
*);
718 extern void blk_queue_issue_flush_fn(request_queue_t
*, issue_flush_fn
*);
719 extern int blk_do_ordered(request_queue_t
*, struct request
**);
720 extern unsigned blk_ordered_cur_seq(request_queue_t
*);
721 extern unsigned blk_ordered_req_seq(struct request
*);
722 extern void blk_ordered_complete_seq(request_queue_t
*, unsigned, int);
724 extern int blk_rq_map_sg(request_queue_t
*, struct request
*, struct scatterlist
*);
725 extern void blk_dump_rq_flags(struct request
*, char *);
726 extern void generic_unplug_device(request_queue_t
*);
727 extern void __generic_unplug_device(request_queue_t
*);
728 extern long nr_blockdev_pages(void);
730 int blk_get_queue(request_queue_t
*);
731 request_queue_t
*blk_alloc_queue(gfp_t
);
732 request_queue_t
*blk_alloc_queue_node(gfp_t
, int);
733 extern void blk_put_queue(request_queue_t
*);
738 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
739 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
740 #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
741 extern int blk_queue_start_tag(request_queue_t
*, struct request
*);
742 extern struct request
*blk_queue_find_tag(request_queue_t
*, int);
743 extern void blk_queue_end_tag(request_queue_t
*, struct request
*);
744 extern int blk_queue_init_tags(request_queue_t
*, int, struct blk_queue_tag
*);
745 extern void blk_queue_free_tags(request_queue_t
*);
746 extern int blk_queue_resize_tags(request_queue_t
*, int);
747 extern void blk_queue_invalidate_tags(request_queue_t
*);
748 extern long blk_congestion_wait(int rw
, long timeout
);
750 extern void blk_rq_bio_prep(request_queue_t
*, struct request
*, struct bio
*);
751 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
753 #define MAX_PHYS_SEGMENTS 128
754 #define MAX_HW_SEGMENTS 128
755 #define SAFE_MAX_SECTORS 255
756 #define BLK_DEF_MAX_SECTORS 1024
758 #define MAX_SEGMENT_SIZE 65536
760 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
762 static inline int queue_hardsect_size(request_queue_t
*q
)
766 if (q
&& q
->hardsect_size
)
767 retval
= q
->hardsect_size
;
772 static inline int bdev_hardsect_size(struct block_device
*bdev
)
774 return queue_hardsect_size(bdev_get_queue(bdev
));
777 static inline int queue_dma_alignment(request_queue_t
*q
)
781 if (q
&& q
->dma_alignment
)
782 retval
= q
->dma_alignment
;
787 static inline int bdev_dma_aligment(struct block_device
*bdev
)
789 return queue_dma_alignment(bdev_get_queue(bdev
));
792 #define blk_finished_io(nsects) do { } while (0)
793 #define blk_started_io(nsects) do { } while (0)
795 /* assumes size > 256 */
796 static inline unsigned int blksize_bits(unsigned int size
)
798 unsigned int bits
= 8;
802 } while (size
> 256);
806 static inline unsigned int block_size(struct block_device
*bdev
)
808 return bdev
->bd_block_size
;
811 typedef struct {struct page
*v
;} Sector
;
813 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
815 static inline void put_dev_sector(Sector p
)
817 page_cache_release(p
.v
);
821 int kblockd_schedule_work(struct work_struct
*work
);
822 void kblockd_flush(void);
825 # include <asm/div64.h>
826 # define sector_div(a, b) do_div(a, b)
828 # define sector_div(n, b)( \
838 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
839 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
840 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
841 MODULE_ALIAS("block-major-" __stringify(major) "-*")