1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
4 #include <linux/major.h>
5 #include <linux/genhd.h>
6 #include <linux/list.h>
7 #include <linux/timer.h>
8 #include <linux/workqueue.h>
9 #include <linux/pagemap.h>
10 #include <linux/backing-dev.h>
11 #include <linux/wait.h>
12 #include <linux/mempool.h>
13 #include <linux/bio.h>
14 #include <linux/module.h>
15 #include <linux/stringify.h>
17 #include <asm/scatterlist.h>
19 struct scsi_ioctl_command
;
22 typedef struct request_queue request_queue_t
;
23 struct elevator_queue
;
24 typedef struct elevator_queue elevator_t
;
25 struct request_pm_state
;
28 #define BLKDEV_MIN_RQ 4
29 #define BLKDEV_MAX_RQ 128 /* Default maximum */
32 * This is the per-process anticipatory I/O scheduler state.
34 struct as_io_context
{
37 void (*dtor
)(struct as_io_context
*aic
); /* destructor */
38 void (*exit
)(struct as_io_context
*aic
); /* called on task exit */
41 atomic_t nr_queued
; /* queued reads & sync writes */
42 atomic_t nr_dispatched
; /* number of requests gone to the drivers */
44 /* IO History tracking */
46 unsigned long last_end_request
;
47 unsigned long ttime_total
;
48 unsigned long ttime_samples
;
49 unsigned long ttime_mean
;
51 unsigned int seek_samples
;
52 sector_t last_request_pos
;
58 struct cfq_io_context
{
59 struct rb_node rb_node
;
62 struct cfq_queue
*cfqq
[2];
64 struct io_context
*ioc
;
66 unsigned long last_end_request
;
67 sector_t last_request_pos
;
68 unsigned long last_queue
;
70 unsigned long ttime_total
;
71 unsigned long ttime_samples
;
72 unsigned long ttime_mean
;
74 unsigned int seek_samples
;
78 struct list_head queue_list
;
80 void (*dtor
)(struct io_context
*); /* destructor */
81 void (*exit
)(struct io_context
*); /* called on task exit */
85 * This is the per-process I/O subsystem state. It is refcounted and
86 * kmalloc'ed. Currently all fields are modified in process io context
87 * (apart from the atomic refcount), so require no locking.
91 struct task_struct
*task
;
93 int (*set_ioprio
)(struct io_context
*, unsigned int);
96 * For request batching
98 unsigned long last_waited
; /* Time last woken after wait for request */
99 int nr_batch_requests
; /* Number of requests left in the batch */
101 struct as_io_context
*aic
;
102 struct rb_root cic_root
;
105 void put_io_context(struct io_context
*ioc
);
106 void exit_io_context(void);
107 struct io_context
*current_io_context(gfp_t gfp_flags
);
108 struct io_context
*get_io_context(gfp_t gfp_flags
);
109 void copy_io_context(struct io_context
**pdst
, struct io_context
**psrc
);
110 void swap_io_context(struct io_context
**ioc1
, struct io_context
**ioc2
);
113 typedef void (rq_end_io_fn
)(struct request
*, int);
115 struct request_list
{
120 wait_queue_head_t wait
[2];
124 * request command types
126 enum rq_cmd_type_bits
{
127 REQ_TYPE_FS
= 1, /* fs request */
128 REQ_TYPE_BLOCK_PC
, /* scsi command */
129 REQ_TYPE_SENSE
, /* sense request */
130 REQ_TYPE_PM_SUSPEND
, /* suspend request */
131 REQ_TYPE_PM_RESUME
, /* resume request */
132 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
133 REQ_TYPE_FLUSH
, /* flush request */
134 REQ_TYPE_SPECIAL
, /* driver defined type */
135 REQ_TYPE_LINUX_BLOCK
, /* generic block layer message */
137 * for ATA/ATAPI devices. this really doesn't belong here, ide should
138 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
139 * private REQ_LB opcodes to differentiate what type of request this is
143 REQ_TYPE_ATA_TASKFILE
,
147 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
148 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
151 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
152 * typically to differentiate REQ_TYPE_SPECIAL requests.
157 * just examples for now
159 REQ_LB_OP_EJECT
= 0x40, /* eject request */
160 REQ_LB_OP_FLUSH
= 0x41, /* flush device */
164 * request type modified bits. first three bits match BIO_RW* bits, important
167 __REQ_RW
, /* not set, read. set, write */
168 __REQ_FAILFAST
, /* no low level driver retries */
169 __REQ_SORTED
, /* elevator knows about this request */
170 __REQ_SOFTBARRIER
, /* may not be passed by ioscheduler */
171 __REQ_HARDBARRIER
, /* may not be passed by drive either */
172 __REQ_FUA
, /* forced unit access */
173 __REQ_NOMERGE
, /* don't touch this for merging */
174 __REQ_STARTED
, /* drive already may have started this one */
175 __REQ_DONTPREP
, /* don't call prep for this one */
176 __REQ_QUEUED
, /* uses queueing */
177 __REQ_ELVPRIV
, /* elevator private data attached */
178 __REQ_FAILED
, /* set if the request failed */
179 __REQ_QUIET
, /* don't worry about errors */
180 __REQ_PREEMPT
, /* set for "ide_preempt" requests */
181 __REQ_ORDERED_COLOR
, /* is before or after barrier */
182 __REQ_RW_SYNC
, /* request is sync (O_DIRECT) */
183 __REQ_NR_BITS
, /* stops here */
186 #define REQ_RW (1 << __REQ_RW)
187 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
188 #define REQ_SORTED (1 << __REQ_SORTED)
189 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
190 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
191 #define REQ_FUA (1 << __REQ_FUA)
192 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
193 #define REQ_STARTED (1 << __REQ_STARTED)
194 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
195 #define REQ_QUEUED (1 << __REQ_QUEUED)
196 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
197 #define REQ_FAILED (1 << __REQ_FAILED)
198 #define REQ_QUIET (1 << __REQ_QUIET)
199 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
200 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
201 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
203 #define BLK_MAX_CDB 16
206 * try to put the fields that are referenced together in the same cacheline
209 struct list_head queuelist
;
210 struct list_head donelist
;
212 unsigned int cmd_flags
;
213 enum rq_cmd_type_bits cmd_type
;
215 /* Maintain bio traversal state for part by part I/O submission.
216 * hard_* are block layer internals, no driver should touch them!
219 sector_t sector
; /* next sector to submit */
220 unsigned long nr_sectors
; /* no. of sectors left to submit */
221 /* no. of sectors left to submit in the current segment */
222 unsigned int current_nr_sectors
;
224 sector_t hard_sector
; /* next sector to complete */
225 unsigned long hard_nr_sectors
; /* no. of sectors left to complete */
226 /* no. of sectors left to complete in the current segment */
227 unsigned int hard_cur_sectors
;
232 struct hlist_node hash
; /* merge hash */
233 struct rb_node rb_node
; /* sort/lookup */
236 * two pointers are available for the IO schedulers, if they need
237 * more they have to dynamically allocate it.
239 void *elevator_private
;
240 void *elevator_private2
;
242 void *completion_data
;
244 int rq_status
; /* should split this into a few status bits */
246 struct gendisk
*rq_disk
;
247 unsigned long start_time
;
249 /* Number of scatter-gather DMA addr+len pairs after
250 * physical address coalescing is performed.
252 unsigned short nr_phys_segments
;
254 /* Number of scatter-gather addr+len pairs after
255 * physical and DMA remapping hardware coalescing is performed.
256 * This is the number of scatter-gather entries the driver
257 * will actually have to deal with after DMA mapping is done.
259 unsigned short nr_hw_segments
;
261 unsigned short ioprio
;
267 struct request_list
*rl
;
273 * when request is used as a packet command carrier
275 unsigned int cmd_len
;
276 unsigned char cmd
[BLK_MAX_CDB
];
278 unsigned int data_len
;
279 unsigned int sense_len
;
283 unsigned int timeout
;
287 * completion callback.
289 rq_end_io_fn
*end_io
;
294 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
295 * requests. Some step values could eventually be made generic.
297 struct request_pm_state
299 /* PM state machine step value, currently driver specific */
301 /* requested PM state value (S1, S2, S3, S4, ...) */
303 void* data
; /* for driver use */
306 #include <linux/elevator.h>
308 typedef int (merge_request_fn
) (request_queue_t
*, struct request
*,
310 typedef int (merge_requests_fn
) (request_queue_t
*, struct request
*,
312 typedef void (request_fn_proc
) (request_queue_t
*q
);
313 typedef int (make_request_fn
) (request_queue_t
*q
, struct bio
*bio
);
314 typedef int (prep_rq_fn
) (request_queue_t
*, struct request
*);
315 typedef void (unplug_fn
) (request_queue_t
*);
318 typedef int (merge_bvec_fn
) (request_queue_t
*, struct bio
*, struct bio_vec
*);
319 typedef void (activity_fn
) (void *data
, int rw
);
320 typedef int (issue_flush_fn
) (request_queue_t
*, struct gendisk
*, sector_t
*);
321 typedef void (prepare_flush_fn
) (request_queue_t
*, struct request
*);
322 typedef void (softirq_done_fn
)(struct request
*);
324 enum blk_queue_state
{
329 struct blk_queue_tag
{
330 struct request
**tag_index
; /* map of busy tags */
331 unsigned long *tag_map
; /* bit map of free/busy tags */
332 struct list_head busy_list
; /* fifo list of busy tags */
333 int busy
; /* current depth */
334 int max_depth
; /* what we will send to device */
335 int real_max_depth
; /* what the array can hold */
336 atomic_t refcnt
; /* map can be shared */
342 * Together with queue_head for cacheline sharing
344 struct list_head queue_head
;
345 struct request
*last_merge
;
346 elevator_t
*elevator
;
349 * the queue request freelist, one for reads and one for writes
351 struct request_list rq
;
353 request_fn_proc
*request_fn
;
354 merge_request_fn
*back_merge_fn
;
355 merge_request_fn
*front_merge_fn
;
356 merge_requests_fn
*merge_requests_fn
;
357 make_request_fn
*make_request_fn
;
358 prep_rq_fn
*prep_rq_fn
;
359 unplug_fn
*unplug_fn
;
360 merge_bvec_fn
*merge_bvec_fn
;
361 activity_fn
*activity_fn
;
362 issue_flush_fn
*issue_flush_fn
;
363 prepare_flush_fn
*prepare_flush_fn
;
364 softirq_done_fn
*softirq_done_fn
;
367 * Dispatch queue sorting
370 struct request
*boundary_rq
;
373 * Auto-unplugging state
375 struct timer_list unplug_timer
;
376 int unplug_thresh
; /* After this many requests */
377 unsigned long unplug_delay
; /* After this many jiffies */
378 struct work_struct unplug_work
;
380 struct backing_dev_info backing_dev_info
;
383 * The queue owner gets to use this for whatever they like.
384 * ll_rw_blk doesn't touch it.
391 * queue needs bounce pages for pages above this limit
393 unsigned long bounce_pfn
;
397 * various queue flags, see QUEUE_* below
399 unsigned long queue_flags
;
402 * protects queue structures from reentrancy. ->__queue_lock should
403 * _never_ be used directly, it is queue private. always use
406 spinlock_t __queue_lock
;
407 spinlock_t
*queue_lock
;
417 unsigned long nr_requests
; /* Max # of requests */
418 unsigned int nr_congestion_on
;
419 unsigned int nr_congestion_off
;
420 unsigned int nr_batching
;
422 unsigned int max_sectors
;
423 unsigned int max_hw_sectors
;
424 unsigned short max_phys_segments
;
425 unsigned short max_hw_segments
;
426 unsigned short hardsect_size
;
427 unsigned int max_segment_size
;
429 unsigned long seg_boundary_mask
;
430 unsigned int dma_alignment
;
432 struct blk_queue_tag
*queue_tags
;
434 unsigned int nr_sorted
;
435 unsigned int in_flight
;
440 unsigned int sg_timeout
;
441 unsigned int sg_reserved_size
;
443 #ifdef CONFIG_BLK_DEV_IO_TRACE
444 struct blk_trace
*blk_trace
;
447 * reserved for flush operations
449 unsigned int ordered
, next_ordered
, ordseq
;
450 int orderr
, ordcolor
;
451 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
452 struct request
*orig_bar_rq
;
453 unsigned int bi_size
;
455 struct mutex sysfs_lock
;
458 #define RQ_INACTIVE (-1)
461 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
462 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
463 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
464 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
465 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
466 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
467 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
468 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
469 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
473 * Hardbarrier is supported with one of the following methods.
475 * NONE : hardbarrier unsupported
476 * DRAIN : ordering by draining is enough
477 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
478 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
479 * TAG : ordering by tag is enough
480 * TAG_FLUSH : ordering by tag w/ pre and post flushes
481 * TAG_FUA : ordering by tag w/ pre flush and FUA write
483 QUEUE_ORDERED_NONE
= 0x00,
484 QUEUE_ORDERED_DRAIN
= 0x01,
485 QUEUE_ORDERED_TAG
= 0x02,
487 QUEUE_ORDERED_PREFLUSH
= 0x10,
488 QUEUE_ORDERED_POSTFLUSH
= 0x20,
489 QUEUE_ORDERED_FUA
= 0x40,
491 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
492 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
493 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
494 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
495 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
496 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
497 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
498 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
501 * Ordered operation sequence
503 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
504 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
505 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
506 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
507 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
508 QUEUE_ORDSEQ_DONE
= 0x20,
511 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
512 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
513 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
514 #define blk_queue_flushing(q) ((q)->ordseq)
516 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
517 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
518 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
519 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
521 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
522 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
524 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
526 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
527 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
528 #define blk_pm_request(rq) \
529 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
531 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
532 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
533 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
535 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
537 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
540 * We regard a request as sync, if it's a READ or a SYNC write.
542 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
544 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
547 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
548 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
551 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
554 set_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
556 set_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
559 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
562 clear_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
564 clear_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
569 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
570 * it already be started by driver.
572 #define RQ_NOMERGE_FLAGS \
573 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
574 #define rq_mergeable(rq) \
575 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
578 * noop, requests are automagically marked as active/inactive by I/O
579 * scheduler -- see elv_next_request
581 #define blk_queue_headactive(q, head_active)
584 * q->prep_rq_fn return values
586 #define BLKPREP_OK 0 /* serve it */
587 #define BLKPREP_KILL 1 /* fatal error, kill */
588 #define BLKPREP_DEFER 2 /* leave on queue */
590 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
593 * standard bounce addresses:
595 * BLK_BOUNCE_HIGH : bounce all highmem pages
596 * BLK_BOUNCE_ANY : don't bounce anything
597 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
599 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
600 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
601 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
604 extern int init_emergency_isa_pool(void);
605 extern void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
);
607 static inline int init_emergency_isa_pool(void)
611 static inline void blk_queue_bounce(request_queue_t
*q
, struct bio
**bio
)
614 #endif /* CONFIG_MMU */
616 #define rq_for_each_bio(_bio, rq) \
618 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
622 unsigned block_size_bits
;
625 extern int blk_register_queue(struct gendisk
*disk
);
626 extern void blk_unregister_queue(struct gendisk
*disk
);
627 extern void register_disk(struct gendisk
*dev
);
628 extern void generic_make_request(struct bio
*bio
);
629 extern void blk_put_request(struct request
*);
630 extern void __blk_put_request(request_queue_t
*, struct request
*);
631 extern void blk_end_sync_rq(struct request
*rq
, int error
);
632 extern struct request
*blk_get_request(request_queue_t
*, int, gfp_t
);
633 extern void blk_insert_request(request_queue_t
*, struct request
*, int, void *);
634 extern void blk_requeue_request(request_queue_t
*, struct request
*);
635 extern void blk_plug_device(request_queue_t
*);
636 extern int blk_remove_plug(request_queue_t
*);
637 extern void blk_recount_segments(request_queue_t
*, struct bio
*);
638 extern int scsi_cmd_ioctl(struct file
*, struct gendisk
*, unsigned int, void __user
*);
639 extern int sg_scsi_ioctl(struct file
*, struct request_queue
*,
640 struct gendisk
*, struct scsi_ioctl_command __user
*);
641 extern void blk_start_queue(request_queue_t
*q
);
642 extern void blk_stop_queue(request_queue_t
*q
);
643 extern void blk_sync_queue(struct request_queue
*q
);
644 extern void __blk_stop_queue(request_queue_t
*q
);
645 extern void blk_run_queue(request_queue_t
*);
646 extern void blk_queue_activity_fn(request_queue_t
*, activity_fn
*, void *);
647 extern int blk_rq_map_user(request_queue_t
*, struct request
*, void __user
*, unsigned int);
648 extern int blk_rq_unmap_user(struct bio
*, unsigned int);
649 extern int blk_rq_map_kern(request_queue_t
*, struct request
*, void *, unsigned int, gfp_t
);
650 extern int blk_rq_map_user_iov(request_queue_t
*, struct request
*, struct sg_iovec
*, int);
651 extern int blk_execute_rq(request_queue_t
*, struct gendisk
*,
652 struct request
*, int);
653 extern void blk_execute_rq_nowait(request_queue_t
*, struct gendisk
*,
654 struct request
*, int, rq_end_io_fn
*);
656 static inline request_queue_t
*bdev_get_queue(struct block_device
*bdev
)
658 return bdev
->bd_disk
->queue
;
661 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
664 if (bdi
&& bdi
->unplug_io_fn
)
665 bdi
->unplug_io_fn(bdi
, page
);
668 static inline void blk_run_address_space(struct address_space
*mapping
)
671 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
675 * end_request() and friends. Must be called with the request queue spinlock
676 * acquired. All functions called within end_request() _must_be_ atomic.
678 * Several drivers define their own end_request and call
679 * end_that_request_first() and end_that_request_last()
680 * for parts of the original function. This prevents
681 * code duplication in drivers.
683 extern int end_that_request_first(struct request
*, int, int);
684 extern int end_that_request_chunk(struct request
*, int, int);
685 extern void end_that_request_last(struct request
*, int);
686 extern void end_request(struct request
*req
, int uptodate
);
687 extern void blk_complete_request(struct request
*);
689 static inline int rq_all_done(struct request
*rq
, unsigned int nr_bytes
)
691 if (blk_fs_request(rq
))
692 return (nr_bytes
>= (rq
->hard_nr_sectors
<< 9));
693 else if (blk_pc_request(rq
))
694 return nr_bytes
>= rq
->data_len
;
700 * end_that_request_first/chunk() takes an uptodate argument. we account
701 * any value <= as an io error. 0 means -EIO for compatability reasons,
702 * any other < 0 value is the direct error type. An uptodate value of
703 * 1 indicates successful io completion
705 #define end_io_error(uptodate) (unlikely((uptodate) <= 0))
707 static inline void blkdev_dequeue_request(struct request
*req
)
709 elv_dequeue_request(req
->q
, req
);
713 * Access functions for manipulating queue properties
715 extern request_queue_t
*blk_init_queue_node(request_fn_proc
*rfn
,
716 spinlock_t
*lock
, int node_id
);
717 extern request_queue_t
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
718 extern void blk_cleanup_queue(request_queue_t
*);
719 extern void blk_queue_make_request(request_queue_t
*, make_request_fn
*);
720 extern void blk_queue_bounce_limit(request_queue_t
*, u64
);
721 extern void blk_queue_max_sectors(request_queue_t
*, unsigned int);
722 extern void blk_queue_max_phys_segments(request_queue_t
*, unsigned short);
723 extern void blk_queue_max_hw_segments(request_queue_t
*, unsigned short);
724 extern void blk_queue_max_segment_size(request_queue_t
*, unsigned int);
725 extern void blk_queue_hardsect_size(request_queue_t
*, unsigned short);
726 extern void blk_queue_stack_limits(request_queue_t
*t
, request_queue_t
*b
);
727 extern void blk_queue_segment_boundary(request_queue_t
*, unsigned long);
728 extern void blk_queue_prep_rq(request_queue_t
*, prep_rq_fn
*pfn
);
729 extern void blk_queue_merge_bvec(request_queue_t
*, merge_bvec_fn
*);
730 extern void blk_queue_dma_alignment(request_queue_t
*, int);
731 extern void blk_queue_softirq_done(request_queue_t
*, softirq_done_fn
*);
732 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
733 extern int blk_queue_ordered(request_queue_t
*, unsigned, prepare_flush_fn
*);
734 extern void blk_queue_issue_flush_fn(request_queue_t
*, issue_flush_fn
*);
735 extern int blk_do_ordered(request_queue_t
*, struct request
**);
736 extern unsigned blk_ordered_cur_seq(request_queue_t
*);
737 extern unsigned blk_ordered_req_seq(struct request
*);
738 extern void blk_ordered_complete_seq(request_queue_t
*, unsigned, int);
740 extern int blk_rq_map_sg(request_queue_t
*, struct request
*, struct scatterlist
*);
741 extern void blk_dump_rq_flags(struct request
*, char *);
742 extern void generic_unplug_device(request_queue_t
*);
743 extern void __generic_unplug_device(request_queue_t
*);
744 extern long nr_blockdev_pages(void);
746 int blk_get_queue(request_queue_t
*);
747 request_queue_t
*blk_alloc_queue(gfp_t
);
748 request_queue_t
*blk_alloc_queue_node(gfp_t
, int);
749 extern void blk_put_queue(request_queue_t
*);
754 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
755 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
756 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
757 extern int blk_queue_start_tag(request_queue_t
*, struct request
*);
758 extern struct request
*blk_queue_find_tag(request_queue_t
*, int);
759 extern void blk_queue_end_tag(request_queue_t
*, struct request
*);
760 extern int blk_queue_init_tags(request_queue_t
*, int, struct blk_queue_tag
*);
761 extern void blk_queue_free_tags(request_queue_t
*);
762 extern int blk_queue_resize_tags(request_queue_t
*, int);
763 extern void blk_queue_invalidate_tags(request_queue_t
*);
764 extern long blk_congestion_wait(int rw
, long timeout
);
765 extern struct blk_queue_tag
*blk_init_tags(int);
766 extern void blk_free_tags(struct blk_queue_tag
*);
767 extern void blk_congestion_end(int rw
);
769 extern void blk_rq_bio_prep(request_queue_t
*, struct request
*, struct bio
*);
770 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
772 #define MAX_PHYS_SEGMENTS 128
773 #define MAX_HW_SEGMENTS 128
774 #define SAFE_MAX_SECTORS 255
775 #define BLK_DEF_MAX_SECTORS 1024
777 #define MAX_SEGMENT_SIZE 65536
779 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
781 static inline int queue_hardsect_size(request_queue_t
*q
)
785 if (q
&& q
->hardsect_size
)
786 retval
= q
->hardsect_size
;
791 static inline int bdev_hardsect_size(struct block_device
*bdev
)
793 return queue_hardsect_size(bdev_get_queue(bdev
));
796 static inline int queue_dma_alignment(request_queue_t
*q
)
800 if (q
&& q
->dma_alignment
)
801 retval
= q
->dma_alignment
;
806 static inline int bdev_dma_aligment(struct block_device
*bdev
)
808 return queue_dma_alignment(bdev_get_queue(bdev
));
811 #define blk_finished_io(nsects) do { } while (0)
812 #define blk_started_io(nsects) do { } while (0)
814 /* assumes size > 256 */
815 static inline unsigned int blksize_bits(unsigned int size
)
817 unsigned int bits
= 8;
821 } while (size
> 256);
825 static inline unsigned int block_size(struct block_device
*bdev
)
827 return bdev
->bd_block_size
;
830 typedef struct {struct page
*v
;} Sector
;
832 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
834 static inline void put_dev_sector(Sector p
)
836 page_cache_release(p
.v
);
840 int kblockd_schedule_work(struct work_struct
*work
);
841 void kblockd_flush(void);
844 # include <asm/div64.h>
845 # define sector_div(a, b) do_div(a, b)
847 # define sector_div(n, b)( \
857 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
858 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
859 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
860 MODULE_ALIAS("block-major-" __stringify(major) "-*")