[SPARC64]: Update defconfig.
[linux-2.6/verdex.git] / include / linux / blkdev.h
blob860e7a485a5f08d2aaa10129d65c6339c128a008
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>
20 struct request_queue;
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 {
33 spinlock_t lock;
35 void (*dtor)(struct as_io_context *aic); /* destructor */
36 void (*exit)(struct as_io_context *aic); /* called on task exit */
38 unsigned long state;
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 */
43 /* Thinktime */
44 unsigned long last_end_request;
45 unsigned long ttime_total;
46 unsigned long ttime_samples;
47 unsigned long ttime_mean;
48 /* Layout pattern */
49 unsigned int seek_samples;
50 sector_t last_request_pos;
51 u64 seek_total;
52 sector_t seek_mean;
55 struct cfq_queue;
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;
62 void *key;
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.
81 struct io_context {
82 atomic_t refcount;
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);
104 struct request;
105 typedef void (rq_end_io_fn)(struct request *, int);
107 struct request_list {
108 int count[2];
109 int starved[2];
110 int elvpriv;
111 mempool_t *rq_pool;
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
120 struct request {
121 struct list_head queuelist;
122 struct list_head donelist;
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;
140 struct bio *bio;
141 struct bio *biotail;
143 void *elevator_private;
144 void *completion_data;
146 unsigned short ioprio;
148 int rq_status; /* should split this into a few status bits */
149 struct gendisk *rq_disk;
150 int errors;
151 unsigned long start_time;
153 /* Number of scatter-gather DMA addr+len pairs after
154 * physical address coalescing is performed.
156 unsigned short nr_phys_segments;
158 /* Number of scatter-gather addr+len pairs after
159 * physical and DMA remapping hardware coalescing is performed.
160 * This is the number of scatter-gather entries the driver
161 * will actually have to deal with after DMA mapping is done.
163 unsigned short nr_hw_segments;
165 int tag;
166 char *buffer;
168 int ref_count;
169 request_queue_t *q;
170 struct request_list *rl;
172 struct completion *waiting;
173 void *special;
176 * when request is used as a packet command carrier
178 unsigned int cmd_len;
179 unsigned char cmd[BLK_MAX_CDB];
181 unsigned int data_len;
182 void *data;
184 unsigned int sense_len;
185 void *sense;
187 unsigned int timeout;
188 int retries;
191 * For Power Management requests
193 struct request_pm_state *pm;
196 * completion callback. end_io_data should be folded in with waiting
198 rq_end_io_fn *end_io;
199 void *end_io_data;
203 * first three bits match BIO_RW* bits, important
205 enum rq_flag_bits {
206 __REQ_RW, /* not set, read. set, write */
207 __REQ_FAILFAST, /* no low level driver retries */
208 __REQ_SORTED, /* elevator knows about this request */
209 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
210 __REQ_HARDBARRIER, /* may not be passed by drive either */
211 __REQ_FUA, /* forced unit access */
212 __REQ_CMD, /* is a regular fs rw request */
213 __REQ_NOMERGE, /* don't touch this for merging */
214 __REQ_STARTED, /* drive already may have started this one */
215 __REQ_DONTPREP, /* don't call prep for this one */
216 __REQ_QUEUED, /* uses queueing */
217 __REQ_ELVPRIV, /* elevator private data attached */
219 * for ATA/ATAPI devices
221 __REQ_PC, /* packet command (special) */
222 __REQ_BLOCK_PC, /* queued down pc from block layer */
223 __REQ_SENSE, /* sense retrival */
225 __REQ_FAILED, /* set if the request failed */
226 __REQ_QUIET, /* don't worry about errors */
227 __REQ_SPECIAL, /* driver suplied command */
228 __REQ_DRIVE_CMD,
229 __REQ_DRIVE_TASK,
230 __REQ_DRIVE_TASKFILE,
231 __REQ_PREEMPT, /* set for "ide_preempt" requests */
232 __REQ_PM_SUSPEND, /* suspend request */
233 __REQ_PM_RESUME, /* resume request */
234 __REQ_PM_SHUTDOWN, /* shutdown request */
235 __REQ_ORDERED_COLOR, /* is before or after barrier */
236 __REQ_NR_BITS, /* stops here */
239 #define REQ_RW (1 << __REQ_RW)
240 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
241 #define REQ_SORTED (1 << __REQ_SORTED)
242 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
243 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
244 #define REQ_FUA (1 << __REQ_FUA)
245 #define REQ_CMD (1 << __REQ_CMD)
246 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
247 #define REQ_STARTED (1 << __REQ_STARTED)
248 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
249 #define REQ_QUEUED (1 << __REQ_QUEUED)
250 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
251 #define REQ_PC (1 << __REQ_PC)
252 #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
253 #define REQ_SENSE (1 << __REQ_SENSE)
254 #define REQ_FAILED (1 << __REQ_FAILED)
255 #define REQ_QUIET (1 << __REQ_QUIET)
256 #define REQ_SPECIAL (1 << __REQ_SPECIAL)
257 #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
258 #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
259 #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
260 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
261 #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
262 #define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
263 #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
264 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
267 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
268 * requests. Some step values could eventually be made generic.
270 struct request_pm_state
272 /* PM state machine step value, currently driver specific */
273 int pm_step;
274 /* requested PM state value (S1, S2, S3, S4, ...) */
275 u32 pm_state;
276 void* data; /* for driver use */
279 #include <linux/elevator.h>
281 typedef int (merge_request_fn) (request_queue_t *, struct request *,
282 struct bio *);
283 typedef int (merge_requests_fn) (request_queue_t *, struct request *,
284 struct request *);
285 typedef void (request_fn_proc) (request_queue_t *q);
286 typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
287 typedef int (prep_rq_fn) (request_queue_t *, struct request *);
288 typedef void (unplug_fn) (request_queue_t *);
290 struct bio_vec;
291 typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
292 typedef void (activity_fn) (void *data, int rw);
293 typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
294 typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
295 typedef void (softirq_done_fn)(struct request *);
297 enum blk_queue_state {
298 Queue_down,
299 Queue_up,
302 struct blk_queue_tag {
303 struct request **tag_index; /* map of busy tags */
304 unsigned long *tag_map; /* bit map of free/busy tags */
305 struct list_head busy_list; /* fifo list of busy tags */
306 int busy; /* current depth */
307 int max_depth; /* what we will send to device */
308 int real_max_depth; /* what the array can hold */
309 atomic_t refcnt; /* map can be shared */
312 struct request_queue
315 * Together with queue_head for cacheline sharing
317 struct list_head queue_head;
318 struct request *last_merge;
319 elevator_t *elevator;
322 * the queue request freelist, one for reads and one for writes
324 struct request_list rq;
326 request_fn_proc *request_fn;
327 merge_request_fn *back_merge_fn;
328 merge_request_fn *front_merge_fn;
329 merge_requests_fn *merge_requests_fn;
330 make_request_fn *make_request_fn;
331 prep_rq_fn *prep_rq_fn;
332 unplug_fn *unplug_fn;
333 merge_bvec_fn *merge_bvec_fn;
334 activity_fn *activity_fn;
335 issue_flush_fn *issue_flush_fn;
336 prepare_flush_fn *prepare_flush_fn;
337 softirq_done_fn *softirq_done_fn;
340 * Dispatch queue sorting
342 sector_t end_sector;
343 struct request *boundary_rq;
346 * Auto-unplugging state
348 struct timer_list unplug_timer;
349 int unplug_thresh; /* After this many requests */
350 unsigned long unplug_delay; /* After this many jiffies */
351 struct work_struct unplug_work;
353 struct backing_dev_info backing_dev_info;
356 * The queue owner gets to use this for whatever they like.
357 * ll_rw_blk doesn't touch it.
359 void *queuedata;
361 void *activity_data;
364 * queue needs bounce pages for pages above this limit
366 unsigned long bounce_pfn;
367 gfp_t bounce_gfp;
370 * various queue flags, see QUEUE_* below
372 unsigned long queue_flags;
375 * protects queue structures from reentrancy. ->__queue_lock should
376 * _never_ be used directly, it is queue private. always use
377 * ->queue_lock.
379 spinlock_t __queue_lock;
380 spinlock_t *queue_lock;
383 * queue kobject
385 struct kobject kobj;
388 * queue settings
390 unsigned long nr_requests; /* Max # of requests */
391 unsigned int nr_congestion_on;
392 unsigned int nr_congestion_off;
393 unsigned int nr_batching;
395 unsigned int max_sectors;
396 unsigned int max_hw_sectors;
397 unsigned short max_phys_segments;
398 unsigned short max_hw_segments;
399 unsigned short hardsect_size;
400 unsigned int max_segment_size;
402 unsigned long seg_boundary_mask;
403 unsigned int dma_alignment;
405 struct blk_queue_tag *queue_tags;
407 atomic_t refcnt;
409 unsigned int nr_sorted;
410 unsigned int in_flight;
413 * sg stuff
415 unsigned int sg_timeout;
416 unsigned int sg_reserved_size;
417 int node;
420 * reserved for flush operations
422 unsigned int ordered, next_ordered, ordseq;
423 int orderr, ordcolor;
424 struct request pre_flush_rq, bar_rq, post_flush_rq;
425 struct request *orig_bar_rq;
426 unsigned int bi_size;
429 #define RQ_INACTIVE (-1)
430 #define RQ_ACTIVE 1
431 #define RQ_SCSI_BUSY 0xffff
432 #define RQ_SCSI_DONE 0xfffe
433 #define RQ_SCSI_DISCONNECTING 0xffe0
435 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
436 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
437 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
438 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
439 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
440 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
441 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
442 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
443 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
445 enum {
447 * Hardbarrier is supported with one of the following methods.
449 * NONE : hardbarrier unsupported
450 * DRAIN : ordering by draining is enough
451 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
452 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
453 * TAG : ordering by tag is enough
454 * TAG_FLUSH : ordering by tag w/ pre and post flushes
455 * TAG_FUA : ordering by tag w/ pre flush and FUA write
457 QUEUE_ORDERED_NONE = 0x00,
458 QUEUE_ORDERED_DRAIN = 0x01,
459 QUEUE_ORDERED_TAG = 0x02,
461 QUEUE_ORDERED_PREFLUSH = 0x10,
462 QUEUE_ORDERED_POSTFLUSH = 0x20,
463 QUEUE_ORDERED_FUA = 0x40,
465 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
466 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
467 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
468 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
469 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
470 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
471 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
472 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
475 * Ordered operation sequence
477 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
478 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
479 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
480 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
481 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
482 QUEUE_ORDSEQ_DONE = 0x20,
485 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
486 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
487 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
488 #define blk_queue_flushing(q) ((q)->ordseq)
490 #define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
491 #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
492 #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
493 #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
495 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
497 #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
498 #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
499 #define blk_pm_request(rq) \
500 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
502 #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
503 #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
504 #define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
506 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
508 #define rq_data_dir(rq) ((rq)->flags & 1)
510 static inline int blk_queue_full(struct request_queue *q, int rw)
512 if (rw == READ)
513 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
514 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
517 static inline void blk_set_queue_full(struct request_queue *q, int rw)
519 if (rw == READ)
520 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
521 else
522 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
525 static inline void blk_clear_queue_full(struct request_queue *q, int rw)
527 if (rw == READ)
528 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
529 else
530 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
535 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
536 * it already be started by driver.
538 #define RQ_NOMERGE_FLAGS \
539 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
540 #define rq_mergeable(rq) \
541 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
544 * noop, requests are automagically marked as active/inactive by I/O
545 * scheduler -- see elv_next_request
547 #define blk_queue_headactive(q, head_active)
550 * q->prep_rq_fn return values
552 #define BLKPREP_OK 0 /* serve it */
553 #define BLKPREP_KILL 1 /* fatal error, kill */
554 #define BLKPREP_DEFER 2 /* leave on queue */
556 extern unsigned long blk_max_low_pfn, blk_max_pfn;
559 * standard bounce addresses:
561 * BLK_BOUNCE_HIGH : bounce all highmem pages
562 * BLK_BOUNCE_ANY : don't bounce anything
563 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
565 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
566 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
567 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
569 #ifdef CONFIG_MMU
570 extern int init_emergency_isa_pool(void);
571 extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
572 #else
573 static inline int init_emergency_isa_pool(void)
575 return 0;
577 static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
580 #endif /* CONFIG_MMU */
582 #define rq_for_each_bio(_bio, rq) \
583 if ((rq->bio)) \
584 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
586 struct sec_size {
587 unsigned block_size;
588 unsigned block_size_bits;
591 extern int blk_register_queue(struct gendisk *disk);
592 extern void blk_unregister_queue(struct gendisk *disk);
593 extern void register_disk(struct gendisk *dev);
594 extern void generic_make_request(struct bio *bio);
595 extern void blk_put_request(struct request *);
596 extern void __blk_put_request(request_queue_t *, struct request *);
597 extern void blk_end_sync_rq(struct request *rq, int error);
598 extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
599 extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
600 extern void blk_requeue_request(request_queue_t *, struct request *);
601 extern void blk_plug_device(request_queue_t *);
602 extern int blk_remove_plug(request_queue_t *);
603 extern void blk_recount_segments(request_queue_t *, struct bio *);
604 extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
605 extern void blk_start_queue(request_queue_t *q);
606 extern void blk_stop_queue(request_queue_t *q);
607 extern void blk_sync_queue(struct request_queue *q);
608 extern void __blk_stop_queue(request_queue_t *q);
609 extern void blk_run_queue(request_queue_t *);
610 extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
611 extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
612 extern int blk_rq_unmap_user(struct bio *, unsigned int);
613 extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t);
614 extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
615 extern int blk_execute_rq(request_queue_t *, struct gendisk *,
616 struct request *, int);
617 extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *,
618 struct request *, int, rq_end_io_fn *);
620 static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
622 return bdev->bd_disk->queue;
625 static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
626 struct page *page)
628 if (bdi && bdi->unplug_io_fn)
629 bdi->unplug_io_fn(bdi, page);
632 static inline void blk_run_address_space(struct address_space *mapping)
634 if (mapping)
635 blk_run_backing_dev(mapping->backing_dev_info, NULL);
639 * end_request() and friends. Must be called with the request queue spinlock
640 * acquired. All functions called within end_request() _must_be_ atomic.
642 * Several drivers define their own end_request and call
643 * end_that_request_first() and end_that_request_last()
644 * for parts of the original function. This prevents
645 * code duplication in drivers.
647 extern int end_that_request_first(struct request *, int, int);
648 extern int end_that_request_chunk(struct request *, int, int);
649 extern void end_that_request_last(struct request *, int);
650 extern void end_request(struct request *req, int uptodate);
651 extern void blk_complete_request(struct request *);
653 static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
655 if (blk_fs_request(rq))
656 return (nr_bytes >= (rq->hard_nr_sectors << 9));
657 else if (blk_pc_request(rq))
658 return nr_bytes >= rq->data_len;
660 return 0;
664 * end_that_request_first/chunk() takes an uptodate argument. we account
665 * any value <= as an io error. 0 means -EIO for compatability reasons,
666 * any other < 0 value is the direct error type. An uptodate value of
667 * 1 indicates successful io completion
669 #define end_io_error(uptodate) (unlikely((uptodate) <= 0))
671 static inline void blkdev_dequeue_request(struct request *req)
673 elv_dequeue_request(req->q, req);
677 * This should be in elevator.h, but that requires pulling in rq and q
679 static inline void elv_dispatch_add_tail(struct request_queue *q,
680 struct request *rq)
682 if (q->last_merge == rq)
683 q->last_merge = NULL;
684 q->nr_sorted--;
686 q->end_sector = rq_end_sector(rq);
687 q->boundary_rq = rq;
688 list_add_tail(&rq->queuelist, &q->queue_head);
692 * Access functions for manipulating queue properties
694 extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
695 spinlock_t *lock, int node_id);
696 extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
697 extern void blk_cleanup_queue(request_queue_t *);
698 extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
699 extern void blk_queue_bounce_limit(request_queue_t *, u64);
700 extern void blk_queue_max_sectors(request_queue_t *, unsigned int);
701 extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
702 extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
703 extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
704 extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
705 extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
706 extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
707 extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
708 extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
709 extern void blk_queue_dma_alignment(request_queue_t *, int);
710 extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *);
711 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
712 extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *);
713 extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
714 extern int blk_do_ordered(request_queue_t *, struct request **);
715 extern unsigned blk_ordered_cur_seq(request_queue_t *);
716 extern unsigned blk_ordered_req_seq(struct request *);
717 extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int);
719 extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
720 extern void blk_dump_rq_flags(struct request *, char *);
721 extern void generic_unplug_device(request_queue_t *);
722 extern void __generic_unplug_device(request_queue_t *);
723 extern long nr_blockdev_pages(void);
725 int blk_get_queue(request_queue_t *);
726 request_queue_t *blk_alloc_queue(gfp_t);
727 request_queue_t *blk_alloc_queue_node(gfp_t, int);
728 #define blk_put_queue(q) blk_cleanup_queue((q))
731 * tag stuff
733 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
734 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
735 #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
736 extern int blk_queue_start_tag(request_queue_t *, struct request *);
737 extern struct request *blk_queue_find_tag(request_queue_t *, int);
738 extern void blk_queue_end_tag(request_queue_t *, struct request *);
739 extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
740 extern void blk_queue_free_tags(request_queue_t *);
741 extern int blk_queue_resize_tags(request_queue_t *, int);
742 extern void blk_queue_invalidate_tags(request_queue_t *);
743 extern long blk_congestion_wait(int rw, long timeout);
745 extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
746 extern int blkdev_issue_flush(struct block_device *, sector_t *);
748 #define MAX_PHYS_SEGMENTS 128
749 #define MAX_HW_SEGMENTS 128
750 #define SAFE_MAX_SECTORS 255
751 #define BLK_DEF_MAX_SECTORS 1024
753 #define MAX_SEGMENT_SIZE 65536
755 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
757 static inline int queue_hardsect_size(request_queue_t *q)
759 int retval = 512;
761 if (q && q->hardsect_size)
762 retval = q->hardsect_size;
764 return retval;
767 static inline int bdev_hardsect_size(struct block_device *bdev)
769 return queue_hardsect_size(bdev_get_queue(bdev));
772 static inline int queue_dma_alignment(request_queue_t *q)
774 int retval = 511;
776 if (q && q->dma_alignment)
777 retval = q->dma_alignment;
779 return retval;
782 static inline int bdev_dma_aligment(struct block_device *bdev)
784 return queue_dma_alignment(bdev_get_queue(bdev));
787 #define blk_finished_io(nsects) do { } while (0)
788 #define blk_started_io(nsects) do { } while (0)
790 /* assumes size > 256 */
791 static inline unsigned int blksize_bits(unsigned int size)
793 unsigned int bits = 8;
794 do {
795 bits++;
796 size >>= 1;
797 } while (size > 256);
798 return bits;
801 static inline unsigned int block_size(struct block_device *bdev)
803 return bdev->bd_block_size;
806 typedef struct {struct page *v;} Sector;
808 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
810 static inline void put_dev_sector(Sector p)
812 page_cache_release(p.v);
815 struct work_struct;
816 int kblockd_schedule_work(struct work_struct *work);
817 void kblockd_flush(void);
819 #ifdef CONFIG_LBD
820 # include <asm/div64.h>
821 # define sector_div(a, b) do_div(a, b)
822 #else
823 # define sector_div(n, b)( \
825 int _res; \
826 _res = (n) % (b); \
827 (n) /= (b); \
828 _res; \
831 #endif
833 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
834 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
835 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
836 MODULE_ALIAS("block-major-" __stringify(major) "-*")
839 #endif