[PATCH] Fix hugepage crash on failing mmap()
[linux-block.git] / include / linux / blkdev.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_BLKDEV_H
2#define _LINUX_BLKDEV_H
3
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>
17
18#include <asm/scatterlist.h>
19
20struct request_queue;
21typedef struct request_queue request_queue_t;
22struct elevator_queue;
23typedef struct elevator_queue elevator_t;
24struct request_pm_state;
25
26#define BLKDEV_MIN_RQ 4
27#define BLKDEV_MAX_RQ 128 /* Default maximum */
28
29/*
30 * This is the per-process anticipatory I/O scheduler state.
31 */
32struct as_io_context {
33 spinlock_t lock;
34
35 void (*dtor)(struct as_io_context *aic); /* destructor */
36 void (*exit)(struct as_io_context *aic); /* called on task exit */
37
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 */
41
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;
53};
54
55struct cfq_queue;
56struct cfq_io_context {
1da177e4
LT
57 /*
58 * circular list of cfq_io_contexts belonging to a process io context
59 */
60 struct list_head list;
61 struct cfq_queue *cfqq;
22e2c507
JA
62 void *key;
63
64 struct io_context *ioc;
65
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;
71
72 void (*dtor)(struct cfq_io_context *);
73 void (*exit)(struct cfq_io_context *);
1da177e4
LT
74};
75
76/*
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.
80 */
81struct io_context {
82 atomic_t refcount;
22e2c507
JA
83 struct task_struct *task;
84
85 int (*set_ioprio)(struct io_context *, unsigned int);
1da177e4
LT
86
87 /*
88 * For request batching
89 */
90 unsigned long last_waited; /* Time last woken after wait for request */
91 int nr_batch_requests; /* Number of requests left in the batch */
92
1da177e4
LT
93 struct as_io_context *aic;
94 struct cfq_io_context *cic;
95};
96
97void put_io_context(struct io_context *ioc);
98void exit_io_context(void);
fb3cc432 99struct io_context *current_io_context(int gfp_flags);
1da177e4
LT
100struct io_context *get_io_context(int gfp_flags);
101void copy_io_context(struct io_context **pdst, struct io_context **psrc);
102void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
103
104struct request;
105typedef void (rq_end_io_fn)(struct request *);
106
107struct request_list {
108 int count[2];
109 int starved[2];
110 mempool_t *rq_pool;
111 wait_queue_head_t wait[2];
112 wait_queue_head_t drain;
113};
114
115#define BLK_MAX_CDB 16
116
117/*
118 * try to put the fields that are referenced together in the same cacheline
119 */
120struct request {
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 */
125
126 /* Maintain bio traversal state for part by part I/O submission.
127 * hard_* are block layer internals, no driver should touch them!
128 */
129
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;
134
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;
139
140 struct bio *bio;
141 struct bio *biotail;
142
143 void *elevator_private;
144
22e2c507
JA
145 unsigned short ioprio;
146
1da177e4
LT
147 int rq_status; /* should split this into a few status bits */
148 struct gendisk *rq_disk;
149 int errors;
150 unsigned long start_time;
151
152 /* Number of scatter-gather DMA addr+len pairs after
153 * physical address coalescing is performed.
154 */
155 unsigned short nr_phys_segments;
156
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.
161 */
162 unsigned short nr_hw_segments;
163
164 int tag;
165 char *buffer;
166
167 int ref_count;
168 request_queue_t *q;
169 struct request_list *rl;
170
171 struct completion *waiting;
172 void *special;
173
174 /*
175 * when request is used as a packet command carrier
176 */
177 unsigned int cmd_len;
178 unsigned char cmd[BLK_MAX_CDB];
179
180 unsigned int data_len;
181 void *data;
182
183 unsigned int sense_len;
184 void *sense;
185
186 unsigned int timeout;
187
188 /*
189 * For Power Management requests
190 */
191 struct request_pm_state *pm;
192
193 /*
194 * completion callback. end_io_data should be folded in with waiting
195 */
196 rq_end_io_fn *end_io;
197 void *end_io_data;
198};
199
200/*
201 * first three bits match BIO_RW* bits, important
202 */
203enum rq_flag_bits {
204 __REQ_RW, /* not set, read. set, write */
205 __REQ_FAILFAST, /* no low level driver retries */
206 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
207 __REQ_HARDBARRIER, /* may not be passed by drive either */
208 __REQ_CMD, /* is a regular fs rw request */
209 __REQ_NOMERGE, /* don't touch this for merging */
210 __REQ_STARTED, /* drive already may have started this one */
211 __REQ_DONTPREP, /* don't call prep for this one */
212 __REQ_QUEUED, /* uses queueing */
213 /*
214 * for ATA/ATAPI devices
215 */
216 __REQ_PC, /* packet command (special) */
217 __REQ_BLOCK_PC, /* queued down pc from block layer */
218 __REQ_SENSE, /* sense retrival */
219
220 __REQ_FAILED, /* set if the request failed */
221 __REQ_QUIET, /* don't worry about errors */
222 __REQ_SPECIAL, /* driver suplied command */
223 __REQ_DRIVE_CMD,
224 __REQ_DRIVE_TASK,
225 __REQ_DRIVE_TASKFILE,
226 __REQ_PREEMPT, /* set for "ide_preempt" requests */
227 __REQ_PM_SUSPEND, /* suspend request */
228 __REQ_PM_RESUME, /* resume request */
229 __REQ_PM_SHUTDOWN, /* shutdown request */
230 __REQ_BAR_PREFLUSH, /* barrier pre-flush done */
231 __REQ_BAR_POSTFLUSH, /* barrier post-flush */
232 __REQ_BAR_FLUSH, /* rq is the flush request */
233 __REQ_NR_BITS, /* stops here */
234};
235
236#define REQ_RW (1 << __REQ_RW)
237#define REQ_FAILFAST (1 << __REQ_FAILFAST)
238#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
239#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
240#define REQ_CMD (1 << __REQ_CMD)
241#define REQ_NOMERGE (1 << __REQ_NOMERGE)
242#define REQ_STARTED (1 << __REQ_STARTED)
243#define REQ_DONTPREP (1 << __REQ_DONTPREP)
244#define REQ_QUEUED (1 << __REQ_QUEUED)
245#define REQ_PC (1 << __REQ_PC)
246#define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
247#define REQ_SENSE (1 << __REQ_SENSE)
248#define REQ_FAILED (1 << __REQ_FAILED)
249#define REQ_QUIET (1 << __REQ_QUIET)
250#define REQ_SPECIAL (1 << __REQ_SPECIAL)
251#define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
252#define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
253#define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
254#define REQ_PREEMPT (1 << __REQ_PREEMPT)
255#define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
256#define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
257#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
258#define REQ_BAR_PREFLUSH (1 << __REQ_BAR_PREFLUSH)
259#define REQ_BAR_POSTFLUSH (1 << __REQ_BAR_POSTFLUSH)
260#define REQ_BAR_FLUSH (1 << __REQ_BAR_FLUSH)
261
262/*
263 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
264 * requests. Some step values could eventually be made generic.
265 */
266struct request_pm_state
267{
268 /* PM state machine step value, currently driver specific */
269 int pm_step;
270 /* requested PM state value (S1, S2, S3, S4, ...) */
271 u32 pm_state;
272 void* data; /* for driver use */
273};
274
275#include <linux/elevator.h>
276
277typedef int (merge_request_fn) (request_queue_t *, struct request *,
278 struct bio *);
279typedef int (merge_requests_fn) (request_queue_t *, struct request *,
280 struct request *);
281typedef void (request_fn_proc) (request_queue_t *q);
282typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
283typedef int (prep_rq_fn) (request_queue_t *, struct request *);
284typedef void (unplug_fn) (request_queue_t *);
285
286struct bio_vec;
287typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
288typedef void (activity_fn) (void *data, int rw);
289typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
290typedef int (prepare_flush_fn) (request_queue_t *, struct request *);
291typedef void (end_flush_fn) (request_queue_t *, struct request *);
292
293enum blk_queue_state {
294 Queue_down,
295 Queue_up,
296};
297
1da177e4
LT
298struct blk_queue_tag {
299 struct request **tag_index; /* map of busy tags */
300 unsigned long *tag_map; /* bit map of free/busy tags */
301 struct list_head busy_list; /* fifo list of busy tags */
302 int busy; /* current depth */
303 int max_depth; /* what we will send to device */
1da177e4
LT
304 atomic_t refcnt; /* map can be shared */
305};
306
307struct request_queue
308{
309 /*
310 * Together with queue_head for cacheline sharing
311 */
312 struct list_head queue_head;
313 struct request *last_merge;
314 elevator_t *elevator;
315
316 /*
317 * the queue request freelist, one for reads and one for writes
318 */
319 struct request_list rq;
320
321 request_fn_proc *request_fn;
322 merge_request_fn *back_merge_fn;
323 merge_request_fn *front_merge_fn;
324 merge_requests_fn *merge_requests_fn;
325 make_request_fn *make_request_fn;
326 prep_rq_fn *prep_rq_fn;
327 unplug_fn *unplug_fn;
328 merge_bvec_fn *merge_bvec_fn;
329 activity_fn *activity_fn;
330 issue_flush_fn *issue_flush_fn;
331 prepare_flush_fn *prepare_flush_fn;
332 end_flush_fn *end_flush_fn;
333
334 /*
335 * Auto-unplugging state
336 */
337 struct timer_list unplug_timer;
338 int unplug_thresh; /* After this many requests */
339 unsigned long unplug_delay; /* After this many jiffies */
340 struct work_struct unplug_work;
341
342 struct backing_dev_info backing_dev_info;
343
344 /*
345 * The queue owner gets to use this for whatever they like.
346 * ll_rw_blk doesn't touch it.
347 */
348 void *queuedata;
349
350 void *activity_data;
351
352 /*
353 * queue needs bounce pages for pages above this limit
354 */
355 unsigned long bounce_pfn;
356 unsigned int bounce_gfp;
357
358 /*
359 * various queue flags, see QUEUE_* below
360 */
361 unsigned long queue_flags;
362
363 /*
152587de 364 * protects queue structures from reentrancy. ->__queue_lock should
365 * _never_ be used directly, it is queue private. always use
366 * ->queue_lock.
1da177e4 367 */
152587de 368 spinlock_t __queue_lock;
1da177e4
LT
369 spinlock_t *queue_lock;
370
371 /*
372 * queue kobject
373 */
374 struct kobject kobj;
375
376 /*
377 * queue settings
378 */
379 unsigned long nr_requests; /* Max # of requests */
380 unsigned int nr_congestion_on;
381 unsigned int nr_congestion_off;
382 unsigned int nr_batching;
383
384 unsigned short max_sectors;
385 unsigned short max_hw_sectors;
386 unsigned short max_phys_segments;
387 unsigned short max_hw_segments;
388 unsigned short hardsect_size;
389 unsigned int max_segment_size;
390
391 unsigned long seg_boundary_mask;
392 unsigned int dma_alignment;
393
394 struct blk_queue_tag *queue_tags;
395
396 atomic_t refcnt;
397
398 unsigned int in_flight;
399
400 /*
401 * sg stuff
402 */
403 unsigned int sg_timeout;
404 unsigned int sg_reserved_size;
1946089a 405 int node;
1da177e4
LT
406
407 struct list_head drain_list;
408
409 /*
410 * reserved for flush operations
411 */
412 struct request *flush_rq;
413 unsigned char ordered;
414};
415
416enum {
417 QUEUE_ORDERED_NONE,
418 QUEUE_ORDERED_TAG,
419 QUEUE_ORDERED_FLUSH,
420};
421
422#define RQ_INACTIVE (-1)
423#define RQ_ACTIVE 1
424#define RQ_SCSI_BUSY 0xffff
425#define RQ_SCSI_DONE 0xfffe
426#define RQ_SCSI_DISCONNECTING 0xffe0
427
428#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
429#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
430#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
431#define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
432#define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
433#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
434#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
435#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
436#define QUEUE_FLAG_DRAIN 8 /* draining queue for sched switch */
437#define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */
438
439#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
440#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
441#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
442#define blk_queue_flushing(q) test_bit(QUEUE_FLAG_FLUSH, &(q)->queue_flags)
443
444#define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
445#define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
446#define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
447#define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
448
449#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
450
451#define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
452#define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
453#define blk_pm_request(rq) \
454 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
455
456#define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
457#define blk_barrier_preflush(rq) ((rq)->flags & REQ_BAR_PREFLUSH)
458#define blk_barrier_postflush(rq) ((rq)->flags & REQ_BAR_POSTFLUSH)
459
460#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
461
462#define rq_data_dir(rq) ((rq)->flags & 1)
463
464static inline int blk_queue_full(struct request_queue *q, int rw)
465{
466 if (rw == READ)
467 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
468 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
469}
470
471static inline void blk_set_queue_full(struct request_queue *q, int rw)
472{
473 if (rw == READ)
474 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
475 else
476 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
477}
478
479static inline void blk_clear_queue_full(struct request_queue *q, int rw)
480{
481 if (rw == READ)
482 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
483 else
484 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
485}
486
487
488/*
489 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
490 * it already be started by driver.
491 */
492#define RQ_NOMERGE_FLAGS \
493 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
494#define rq_mergeable(rq) \
495 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
496
497/*
498 * noop, requests are automagically marked as active/inactive by I/O
499 * scheduler -- see elv_next_request
500 */
501#define blk_queue_headactive(q, head_active)
502
503/*
504 * q->prep_rq_fn return values
505 */
506#define BLKPREP_OK 0 /* serve it */
507#define BLKPREP_KILL 1 /* fatal error, kill */
508#define BLKPREP_DEFER 2 /* leave on queue */
509
510extern unsigned long blk_max_low_pfn, blk_max_pfn;
511
512/*
513 * standard bounce addresses:
514 *
515 * BLK_BOUNCE_HIGH : bounce all highmem pages
516 * BLK_BOUNCE_ANY : don't bounce anything
517 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
518 */
519#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
520#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
521#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
522
523#ifdef CONFIG_MMU
524extern int init_emergency_isa_pool(void);
525extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
526#else
527static inline int init_emergency_isa_pool(void)
528{
529 return 0;
530}
531static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
532{
533}
534#endif /* CONFIG_MMU */
535
536#define rq_for_each_bio(_bio, rq) \
537 if ((rq->bio)) \
538 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
539
540struct sec_size {
541 unsigned block_size;
542 unsigned block_size_bits;
543};
544
545extern int blk_register_queue(struct gendisk *disk);
546extern void blk_unregister_queue(struct gendisk *disk);
547extern void register_disk(struct gendisk *dev);
548extern void generic_make_request(struct bio *bio);
549extern void blk_put_request(struct request *);
550extern void blk_end_sync_rq(struct request *rq);
551extern void blk_attempt_remerge(request_queue_t *, struct request *);
1da177e4 552extern struct request *blk_get_request(request_queue_t *, int, int);
867d1191 553extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
1da177e4
LT
554extern void blk_requeue_request(request_queue_t *, struct request *);
555extern void blk_plug_device(request_queue_t *);
556extern int blk_remove_plug(request_queue_t *);
557extern void blk_recount_segments(request_queue_t *, struct bio *);
1da177e4
LT
558extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
559extern void blk_start_queue(request_queue_t *q);
560extern void blk_stop_queue(request_queue_t *q);
561extern void blk_sync_queue(struct request_queue *q);
562extern void __blk_stop_queue(request_queue_t *q);
563extern void blk_run_queue(request_queue_t *);
564extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
565extern struct request *blk_rq_map_user(request_queue_t *, int, void __user *, unsigned int);
566extern int blk_rq_unmap_user(struct request *, struct bio *, unsigned int);
567extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *);
568
569static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
570{
571 return bdev->bd_disk->queue;
572}
573
574static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
575 struct page *page)
576{
577 if (bdi && bdi->unplug_io_fn)
578 bdi->unplug_io_fn(bdi, page);
579}
580
581static inline void blk_run_address_space(struct address_space *mapping)
582{
583 if (mapping)
584 blk_run_backing_dev(mapping->backing_dev_info, NULL);
585}
586
587/*
588 * end_request() and friends. Must be called with the request queue spinlock
589 * acquired. All functions called within end_request() _must_be_ atomic.
590 *
591 * Several drivers define their own end_request and call
592 * end_that_request_first() and end_that_request_last()
593 * for parts of the original function. This prevents
594 * code duplication in drivers.
595 */
596extern int end_that_request_first(struct request *, int, int);
597extern int end_that_request_chunk(struct request *, int, int);
598extern void end_that_request_last(struct request *);
599extern void end_request(struct request *req, int uptodate);
600
601/*
602 * end_that_request_first/chunk() takes an uptodate argument. we account
603 * any value <= as an io error. 0 means -EIO for compatability reasons,
604 * any other < 0 value is the direct error type. An uptodate value of
605 * 1 indicates successful io completion
606 */
607#define end_io_error(uptodate) (unlikely((uptodate) <= 0))
608
609static inline void blkdev_dequeue_request(struct request *req)
610{
611 BUG_ON(list_empty(&req->queuelist));
612
613 list_del_init(&req->queuelist);
614
615 if (req->rl)
616 elv_remove_request(req->q, req);
617}
618
619/*
620 * Access functions for manipulating queue properties
621 */
1946089a
CL
622extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
623 spinlock_t *lock, int node_id);
1da177e4
LT
624extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
625extern void blk_cleanup_queue(request_queue_t *);
626extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
627extern void blk_queue_bounce_limit(request_queue_t *, u64);
628extern void blk_queue_max_sectors(request_queue_t *, unsigned short);
629extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
630extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
631extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
632extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
633extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
634extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
635extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
636extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
637extern void blk_queue_dma_alignment(request_queue_t *, int);
638extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
639extern void blk_queue_ordered(request_queue_t *, int);
640extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
1da177e4
LT
641extern struct request *blk_start_pre_flush(request_queue_t *,struct request *);
642extern int blk_complete_barrier_rq(request_queue_t *, struct request *, int);
643extern int blk_complete_barrier_rq_locked(request_queue_t *, struct request *, int);
644
645extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
646extern void blk_dump_rq_flags(struct request *, char *);
647extern void generic_unplug_device(request_queue_t *);
648extern void __generic_unplug_device(request_queue_t *);
649extern long nr_blockdev_pages(void);
650extern void blk_wait_queue_drained(request_queue_t *, int);
651extern void blk_finish_queue_drain(request_queue_t *);
652
653int blk_get_queue(request_queue_t *);
1946089a
CL
654request_queue_t *blk_alloc_queue(int gfp_mask);
655request_queue_t *blk_alloc_queue_node(int,int);
1da177e4
LT
656#define blk_put_queue(q) blk_cleanup_queue((q))
657
658/*
659 * tag stuff
660 */
661#define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
662#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
663#define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
664extern int blk_queue_start_tag(request_queue_t *, struct request *);
665extern struct request *blk_queue_find_tag(request_queue_t *, int);
666extern void blk_queue_end_tag(request_queue_t *, struct request *);
667extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
668extern void blk_queue_free_tags(request_queue_t *);
669extern int blk_queue_resize_tags(request_queue_t *, int);
670extern void blk_queue_invalidate_tags(request_queue_t *);
671extern long blk_congestion_wait(int rw, long timeout);
672
673extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
674extern int blkdev_issue_flush(struct block_device *, sector_t *);
675
676#define MAX_PHYS_SEGMENTS 128
677#define MAX_HW_SEGMENTS 128
678#define MAX_SECTORS 255
679
680#define MAX_SEGMENT_SIZE 65536
681
682#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
683
1da177e4
LT
684static inline int queue_hardsect_size(request_queue_t *q)
685{
686 int retval = 512;
687
688 if (q && q->hardsect_size)
689 retval = q->hardsect_size;
690
691 return retval;
692}
693
694static inline int bdev_hardsect_size(struct block_device *bdev)
695{
696 return queue_hardsect_size(bdev_get_queue(bdev));
697}
698
699static inline int queue_dma_alignment(request_queue_t *q)
700{
701 int retval = 511;
702
703 if (q && q->dma_alignment)
704 retval = q->dma_alignment;
705
706 return retval;
707}
708
709static inline int bdev_dma_aligment(struct block_device *bdev)
710{
711 return queue_dma_alignment(bdev_get_queue(bdev));
712}
713
714#define blk_finished_io(nsects) do { } while (0)
715#define blk_started_io(nsects) do { } while (0)
716
717/* assumes size > 256 */
718static inline unsigned int blksize_bits(unsigned int size)
719{
720 unsigned int bits = 8;
721 do {
722 bits++;
723 size >>= 1;
724 } while (size > 256);
725 return bits;
726}
727
728extern inline unsigned int block_size(struct block_device *bdev)
729{
730 return bdev->bd_block_size;
731}
732
733typedef struct {struct page *v;} Sector;
734
735unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
736
737static inline void put_dev_sector(Sector p)
738{
739 page_cache_release(p.v);
740}
741
742struct work_struct;
743int kblockd_schedule_work(struct work_struct *work);
744void kblockd_flush(void);
745
746#ifdef CONFIG_LBD
747# include <asm/div64.h>
748# define sector_div(a, b) do_div(a, b)
749#else
750# define sector_div(n, b)( \
751{ \
752 int _res; \
753 _res = (n) % (b); \
754 (n) /= (b); \
755 _res; \
756} \
757)
758#endif
759
760#define MODULE_ALIAS_BLOCKDEV(major,minor) \
761 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
762#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
763 MODULE_ALIAS("block-major-" __stringify(major) "-*")
764
765
766#endif