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_s;
23typedef struct elevator_s elevator_t;
24struct request_pm_state;
25
26#define BLKDEV_MIN_RQ 4
27#define BLKDEV_MAX_RQ 128
28
29
30
31
32struct as_io_context {
33 spinlock_t lock;
34
35 void (*dtor)(struct as_io_context *aic);
36 void (*exit)(struct as_io_context *aic);
37
38 unsigned long state;
39 atomic_t nr_queued;
40 atomic_t nr_dispatched;
41
42
43
44 unsigned long last_end_request;
45 unsigned long ttime_total;
46 unsigned long ttime_samples;
47 unsigned long ttime_mean;
48
49 unsigned int seek_samples;
50 sector_t last_request_pos;
51 u64 seek_total;
52 sector_t seek_mean;
53};
54
55
56
57
58
59
60struct io_context {
61 atomic_t refcount;
62 pid_t pid;
63
64
65
66
67 unsigned long last_waited;
68 int nr_batch_requests;
69
70 struct as_io_context *aic;
71};
72
73void put_io_context(struct io_context *ioc);
74void exit_io_context(void);
75struct io_context *get_io_context(int gfp_flags);
76void copy_io_context(struct io_context **pdst, struct io_context **psrc);
77void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
78
79struct request_list {
80 int count[2];
81 mempool_t *rq_pool;
82 wait_queue_head_t wait[2];
83};
84
85#define BLK_MAX_CDB 16
86
87
88
89
90struct request {
91 struct list_head queuelist;
92
93
94 unsigned long flags;
95
96
97
98
99
100 sector_t sector;
101 unsigned long nr_sectors;
102
103 unsigned int current_nr_sectors;
104
105 sector_t hard_sector;
106 unsigned long hard_nr_sectors;
107
108 unsigned int hard_cur_sectors;
109
110
111 unsigned short nr_cbio_segments;
112
113 unsigned long nr_cbio_sectors;
114
115 struct bio *cbio;
116 struct bio *bio;
117 struct bio *biotail;
118
119 void *elevator_private;
120
121 int rq_status;
122 struct gendisk *rq_disk;
123 int errors;
124 unsigned long start_time;
125
126
127
128
129 unsigned short nr_phys_segments;
130
131
132
133
134
135
136 unsigned short nr_hw_segments;
137
138 int tag;
139 char *buffer;
140
141 int ref_count;
142 request_queue_t *q;
143 struct request_list *rl;
144
145 struct completion *waiting;
146 void *special;
147
148
149
150
151 unsigned int cmd_len;
152 unsigned char cmd[BLK_MAX_CDB];
153
154 unsigned int data_len;
155 void *data;
156
157 unsigned int sense_len;
158 void *sense;
159
160 unsigned int timeout;
161
162
163
164
165 struct request_pm_state *pm;
166};
167
168
169
170
171enum rq_flag_bits {
172 __REQ_RW,
173 __REQ_FAILFAST,
174 __REQ_SOFTBARRIER,
175 __REQ_HARDBARRIER,
176 __REQ_CMD,
177 __REQ_NOMERGE,
178 __REQ_STARTED,
179 __REQ_DONTPREP,
180 __REQ_QUEUED,
181
182
183
184 __REQ_PC,
185 __REQ_BLOCK_PC,
186 __REQ_SENSE,
187
188 __REQ_FAILED,
189 __REQ_QUIET,
190 __REQ_SPECIAL,
191 __REQ_DRIVE_CMD,
192 __REQ_DRIVE_TASK,
193 __REQ_DRIVE_TASKFILE,
194 __REQ_PREEMPT,
195 __REQ_PM_SUSPEND,
196 __REQ_PM_RESUME,
197 __REQ_PM_SHUTDOWN,
198 __REQ_NR_BITS,
199};
200
201#define REQ_RW (1 << __REQ_RW)
202#define REQ_FAILFAST (1 << __REQ_FAILFAST)
203#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
204#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
205#define REQ_CMD (1 << __REQ_CMD)
206#define REQ_NOMERGE (1 << __REQ_NOMERGE)
207#define REQ_STARTED (1 << __REQ_STARTED)
208#define REQ_DONTPREP (1 << __REQ_DONTPREP)
209#define REQ_QUEUED (1 << __REQ_QUEUED)
210#define REQ_PC (1 << __REQ_PC)
211#define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
212#define REQ_SENSE (1 << __REQ_SENSE)
213#define REQ_FAILED (1 << __REQ_FAILED)
214#define REQ_QUIET (1 << __REQ_QUIET)
215#define REQ_SPECIAL (1 << __REQ_SPECIAL)
216#define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
217#define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
218#define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
219#define REQ_PREEMPT (1 << __REQ_PREEMPT)
220#define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
221#define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
222#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
223
224
225
226
227
228struct request_pm_state
229{
230
231 int pm_step;
232
233 u32 pm_state;
234 void* data;
235};
236
237#include <linux/elevator.h>
238
239typedef int (merge_request_fn) (request_queue_t *, struct request *,
240 struct bio *);
241typedef int (merge_requests_fn) (request_queue_t *, struct request *,
242 struct request *);
243typedef void (request_fn_proc) (request_queue_t *q);
244typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
245typedef int (prep_rq_fn) (request_queue_t *, struct request *);
246typedef void (unplug_fn) (request_queue_t *);
247
248struct bio_vec;
249typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
250typedef void (activity_fn) (void *data, int rw);
251
252enum blk_queue_state {
253 Queue_down,
254 Queue_up,
255};
256
257#define BLK_TAGS_PER_LONG (sizeof(unsigned long) * 8)
258#define BLK_TAGS_MASK (BLK_TAGS_PER_LONG - 1)
259
260struct blk_queue_tag {
261 struct request **tag_index;
262 unsigned long *tag_map;
263 struct list_head busy_list;
264 int busy;
265 int max_depth;
266 int real_max_depth;
267 atomic_t refcnt;
268};
269
270struct request_queue
271{
272
273
274
275 struct list_head queue_head;
276 struct request *last_merge;
277 elevator_t elevator;
278
279
280
281
282 struct request_list rq;
283
284 request_fn_proc *request_fn;
285 merge_request_fn *back_merge_fn;
286 merge_request_fn *front_merge_fn;
287 merge_requests_fn *merge_requests_fn;
288 make_request_fn *make_request_fn;
289 prep_rq_fn *prep_rq_fn;
290 unplug_fn *unplug_fn;
291 merge_bvec_fn *merge_bvec_fn;
292 activity_fn *activity_fn;
293
294
295
296
297 struct timer_list unplug_timer;
298 int unplug_thresh;
299 unsigned long unplug_delay;
300 struct work_struct unplug_work;
301
302 struct backing_dev_info backing_dev_info;
303
304
305
306
307
308 void *queuedata;
309
310 void *activity_data;
311
312
313
314
315 unsigned long bounce_pfn;
316 int bounce_gfp;
317
318
319
320
321 unsigned long queue_flags;
322
323
324
325
326 spinlock_t *queue_lock;
327
328
329
330
331 struct kobject kobj;
332
333
334
335
336 unsigned long nr_requests;
337 unsigned int nr_congestion_on;
338 unsigned int nr_congestion_off;
339
340 unsigned short max_sectors;
341 unsigned short max_phys_segments;
342 unsigned short max_hw_segments;
343 unsigned short hardsect_size;
344 unsigned int max_segment_size;
345
346 unsigned long seg_boundary_mask;
347 unsigned int dma_alignment;
348
349 struct blk_queue_tag *queue_tags;
350
351 atomic_t refcnt;
352
353 unsigned int in_flight;
354
355
356
357
358 unsigned int sg_timeout;
359 unsigned int sg_reserved_size;
360};
361
362#define RQ_INACTIVE (-1)
363#define RQ_ACTIVE 1
364#define RQ_SCSI_BUSY 0xffff
365#define RQ_SCSI_DONE 0xfffe
366#define RQ_SCSI_DISCONNECTING 0xffe0
367
368#define QUEUE_FLAG_CLUSTER 0
369#define QUEUE_FLAG_QUEUED 1
370#define QUEUE_FLAG_STOPPED 2
371#define QUEUE_FLAG_READFULL 3
372#define QUEUE_FLAG_WRITEFULL 4
373#define QUEUE_FLAG_DEAD 5
374#define QUEUE_FLAG_REENTER 6
375#define QUEUE_FLAG_PLUGGED 7
376
377#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
378#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
379#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
380
381#define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
382#define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
383#define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
384#define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
385
386#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
387
388#define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
389#define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
390#define blk_pm_request(rq) \
391 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
392
393#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
394
395#define rq_data_dir(rq) ((rq)->flags & 1)
396
397static inline int blk_queue_full(struct request_queue *q, int rw)
398{
399 if (rw == READ)
400 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
401 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
402}
403
404static inline void blk_set_queue_full(struct request_queue *q, int rw)
405{
406 if (rw == READ)
407 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
408 else
409 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
410}
411
412static inline void blk_clear_queue_full(struct request_queue *q, int rw)
413{
414 if (rw == READ)
415 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
416 else
417 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
418}
419
420
421
422
423
424
425#define RQ_NOMERGE_FLAGS \
426 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
427#define rq_mergeable(rq) \
428 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
429
430
431
432
433
434#define blk_queue_headactive(q, head_active)
435
436
437#define blk_rq_idx(rq) ((rq)->cbio->bi_vcnt - (rq)->nr_cbio_segments)
438
439
440#define blk_rq_vec(rq) (bio_iovec_idx((rq)->cbio, blk_rq_idx(rq)))
441
442
443#define blk_rq_offset(rq) \
444 (((rq)->hard_cur_sectors - (rq)->current_nr_sectors) << 9)
445
446
447
448
449
450
451static inline char * rq_map_buffer(struct request *rq, unsigned long *flags)
452{
453 return (__bio_kmap_irq(rq->cbio, blk_rq_idx(rq), flags)
454 + blk_rq_offset(rq));
455}
456
457static inline void rq_unmap_buffer(char *buffer, unsigned long *flags)
458{
459 __bio_kunmap_irq(buffer, flags);
460}
461
462
463
464
465#define BLKPREP_OK 0
466#define BLKPREP_KILL 1
467#define BLKPREP_DEFER 2
468
469extern unsigned long blk_max_low_pfn, blk_max_pfn;
470
471
472
473
474
475
476
477
478#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
479#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
480#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
481
482#ifdef CONFIG_MMU
483extern int init_emergency_isa_pool(void);
484extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
485#else
486static inline int init_emergency_isa_pool(void)
487{
488 return 0;
489}
490static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
491{
492}
493#endif
494
495#define rq_for_each_bio(_bio, rq) \
496 if ((rq->bio)) \
497 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
498
499struct sec_size {
500 unsigned block_size;
501 unsigned block_size_bits;
502};
503
504extern int blk_register_queue(struct gendisk *disk);
505extern void blk_unregister_queue(struct gendisk *disk);
506extern void register_disk(struct gendisk *dev);
507extern void generic_make_request(struct bio *bio);
508extern void blk_put_request(struct request *);
509extern void blk_attempt_remerge(request_queue_t *, struct request *);
510extern void __blk_attempt_remerge(request_queue_t *, struct request *);
511extern struct request *blk_get_request(request_queue_t *, int, int);
512extern void blk_put_request(struct request *);
513extern void blk_insert_request(request_queue_t *, struct request *, int, void *, int);
514extern void blk_requeue_request(request_queue_t *, struct request *);
515extern void blk_plug_device(request_queue_t *);
516extern int blk_remove_plug(request_queue_t *);
517extern void blk_recount_segments(request_queue_t *, struct bio *);
518extern int blk_phys_contig_segment(request_queue_t *q, struct bio *, struct bio *);
519extern int blk_hw_contig_segment(request_queue_t *q, struct bio *, struct bio *);
520extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
521extern void blk_start_queue(request_queue_t *q);
522extern void blk_stop_queue(request_queue_t *q);
523extern void __blk_stop_queue(request_queue_t *q);
524extern void blk_run_queue(request_queue_t *);
525extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
526extern struct request *blk_rq_map_user(request_queue_t *, int, void __user *, unsigned int);
527extern int blk_rq_unmap_user(struct request *, struct bio *, unsigned int);
528extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *);
529
530static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
531{
532 return bdev->bd_disk->queue;
533}
534
535static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
536 struct page *page)
537{
538 if (bdi && bdi->unplug_io_fn)
539 bdi->unplug_io_fn(bdi, page);
540}
541
542static inline void blk_run_address_space(struct address_space *mapping)
543{
544 if (mapping)
545 blk_run_backing_dev(mapping->backing_dev_info, NULL);
546}
547
548
549
550
551
552
553
554
555
556
557extern int end_that_request_first(struct request *, int, int);
558extern int end_that_request_chunk(struct request *, int, int);
559extern void end_that_request_last(struct request *);
560extern int process_that_request_first(struct request *, unsigned int);
561extern void end_request(struct request *req, int uptodate);
562
563static inline void blkdev_dequeue_request(struct request *req)
564{
565 BUG_ON(list_empty(&req->queuelist));
566
567 list_del_init(&req->queuelist);
568
569 if (req->rl)
570 elv_remove_request(req->q, req);
571}
572
573
574
575
576extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
577extern void blk_cleanup_queue(request_queue_t *);
578extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
579extern void blk_queue_bounce_limit(request_queue_t *, u64);
580extern void blk_queue_max_sectors(request_queue_t *, unsigned short);
581extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
582extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
583extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
584extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
585extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
586extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
587extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
588extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
589extern void blk_queue_dma_alignment(request_queue_t *, int);
590extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
591
592extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
593extern void blk_dump_rq_flags(struct request *, char *);
594extern void generic_unplug_device(request_queue_t *);
595extern void __generic_unplug_device(request_queue_t *);
596extern long nr_blockdev_pages(void);
597
598int blk_get_queue(request_queue_t *);
599request_queue_t *blk_alloc_queue(int);
600#define blk_put_queue(q) blk_cleanup_queue((q))
601
602
603
604
605#define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
606#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
607#define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
608extern int blk_queue_start_tag(request_queue_t *, struct request *);
609extern struct request *blk_queue_find_tag(request_queue_t *, int);
610extern void blk_queue_end_tag(request_queue_t *, struct request *);
611extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
612extern void blk_queue_free_tags(request_queue_t *);
613extern int blk_queue_resize_tags(request_queue_t *, int);
614extern void blk_queue_invalidate_tags(request_queue_t *);
615extern long blk_congestion_wait(int rw, long timeout);
616
617extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
618extern void blk_rq_prep_restart(struct request *);
619
620#define MAX_PHYS_SEGMENTS 128
621#define MAX_HW_SEGMENTS 128
622#define MAX_SECTORS 255
623
624#define MAX_SEGMENT_SIZE 65536
625
626#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
627
628extern void drive_stat_acct(struct request *, int, int);
629
630static inline int queue_hardsect_size(request_queue_t *q)
631{
632 int retval = 512;
633
634 if (q && q->hardsect_size)
635 retval = q->hardsect_size;
636
637 return retval;
638}
639
640static inline int bdev_hardsect_size(struct block_device *bdev)
641{
642 return queue_hardsect_size(bdev_get_queue(bdev));
643}
644
645static inline int queue_dma_alignment(request_queue_t *q)
646{
647 int retval = 511;
648
649 if (q && q->dma_alignment)
650 retval = q->dma_alignment;
651
652 return retval;
653}
654
655static inline int bdev_dma_aligment(struct block_device *bdev)
656{
657 return queue_dma_alignment(bdev_get_queue(bdev));
658}
659
660#define blk_finished_io(nsects) do { } while (0)
661#define blk_started_io(nsects) do { } while (0)
662
663
664static inline unsigned int blksize_bits(unsigned int size)
665{
666 unsigned int bits = 8;
667 do {
668 bits++;
669 size >>= 1;
670 } while (size > 256);
671 return bits;
672}
673
674extern inline unsigned int block_size(struct block_device *bdev)
675{
676 return bdev->bd_block_size;
677}
678
679typedef struct {struct page *v;} Sector;
680
681unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
682
683static inline void put_dev_sector(Sector p)
684{
685 page_cache_release(p.v);
686}
687
688struct work_struct;
689int kblockd_schedule_work(struct work_struct *work);
690void kblockd_flush(void);
691
692#ifdef CONFIG_LBD
693# include <asm/div64.h>
694# define sector_div(a, b) do_div(a, b)
695#else
696# define sector_div(n, b)( \
697{ \
698 int _res; \
699 _res = (n) % (b); \
700 (n) /= (b); \
701 _res; \
702} \
703)
704#endif
705
706#define MODULE_ALIAS_BLOCKDEV(major,minor) \
707 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
708#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
709 MODULE_ALIAS("block-major-" __stringify(major) "-*")
710
711
712#endif
713