1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
3
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>
16
17 #include <asm/scatterlist.h>
18
19 struct scsi_ioctl_command;
20
21 struct request_queue;
22 typedef struct request_queue request_queue_t;
23 struct elevator_queue;
24 typedef struct elevator_queue elevator_t;
25 struct request_pm_state;
26 struct blk_trace;
27
28 #define BLKDEV_MIN_RQ 4
29 #define BLKDEV_MAX_RQ 128 /* Default maximum */
30
31 /*
32 * This is the per-process anticipatory I/O scheduler state.
33 */
34 struct as_io_context {
35 spinlock_t lock;
36
37 void (*dtor)(struct as_io_context *aic); /* destructor */
38 void (*exit)(struct as_io_context *aic); /* called on task exit */
39
40 unsigned long state;
41 atomic_t nr_queued; /* queued reads & sync writes */
42 atomic_t nr_dispatched; /* number of requests gone to the drivers */
43
44 /* IO History tracking */
45 /* Thinktime */
46 unsigned long last_end_request;
47 unsigned long ttime_total;
48 unsigned long ttime_samples;
49 unsigned long ttime_mean;
50 /* Layout pattern */
51 unsigned int seek_samples;
52 sector_t last_request_pos;
53 u64 seek_total;
54 sector_t seek_mean;
55 };
56
57 struct cfq_queue;
58 struct cfq_io_context {
59 struct rb_node rb_node;
60 void *key;
61
62 struct cfq_queue *cfqq[2];
63
64 struct io_context *ioc;
65
66 unsigned long last_end_request;
67 sector_t last_request_pos;
68 unsigned long last_queue;
69
70 unsigned long ttime_total;
71 unsigned long ttime_samples;
72 unsigned long ttime_mean;
73
74 unsigned int seek_samples;
75 u64 seek_total;
76 sector_t seek_mean;
77
78 struct list_head queue_list;
79
80 void (*dtor)(struct io_context *); /* destructor */
81 void (*exit)(struct io_context *); /* called on task exit */
82 };
83
84 /*
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.
88 */
89 struct io_context {
90 atomic_t refcount;
91 struct task_struct *task;
92
93 int (*set_ioprio)(struct io_context *, unsigned int);
94
95 /*
96 * For request batching
97 */
98 unsigned long last_waited; /* Time last woken after wait for request */
99 int nr_batch_requests; /* Number of requests left in the batch */
100
101 struct as_io_context *aic;
102 struct rb_root cic_root;
103 };
104
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);
111
112 struct request;
113 typedef void (rq_end_io_fn)(struct request *, int);
114
115 struct request_list {
116 int count[2];
117 int starved[2];
118 int elvpriv;
119 mempool_t *rq_pool;
120 wait_queue_head_t wait[2];
121 };
122
123 #define BLK_MAX_CDB 16
124
125 /*
126 * try to put the fields that are referenced together in the same cacheline
127 */
128 struct request {
129 struct list_head queuelist;
130 struct list_head donelist;
131
132 unsigned long flags; /* see REQ_ bits below */
133
134 /* Maintain bio traversal state for part by part I/O submission.
135 * hard_* are block layer internals, no driver should touch them!
136 */
137
138 sector_t sector; /* next sector to submit */
139 unsigned long nr_sectors; /* no. of sectors left to submit */
140 /* no. of sectors left to submit in the current segment */
141 unsigned int current_nr_sectors;
142
143 sector_t hard_sector; /* next sector to complete */
144 unsigned long hard_nr_sectors; /* no. of sectors left to complete */
145 /* no. of sectors left to complete in the current segment */
146 unsigned int hard_cur_sectors;
147
148 struct bio *bio;
149 struct bio *biotail;
150
151 void *elevator_private;
152 void *completion_data;
153
154 int rq_status; /* should split this into a few status bits */
155 int errors;
156 struct gendisk *rq_disk;
157 unsigned long start_time;
158
159 /* Number of scatter-gather DMA addr+len pairs after
160 * physical address coalescing is performed.
161 */
162 unsigned short nr_phys_segments;
163
164 /* Number of scatter-gather addr+len pairs after
165 * physical and DMA remapping hardware coalescing is performed.
166 * This is the number of scatter-gather entries the driver
167 * will actually have to deal with after DMA mapping is done.
168 */
169 unsigned short nr_hw_segments;
170
171 unsigned short ioprio;
172
173 int tag;
174
175 int ref_count;
176 request_queue_t *q;
177 struct request_list *rl;
178
179 struct completion *waiting;
180 void *special;
181 char *buffer;
182
183 /*
184 * when request is used as a packet command carrier
185 */
186 unsigned int cmd_len;
187 unsigned char cmd[BLK_MAX_CDB];
188
189 unsigned int data_len;
190 unsigned int sense_len;
191 void *data;
192 void *sense;
193
194 unsigned int timeout;
195 int retries;
196
197 /*
198 * completion callback. end_io_data should be folded in with waiting
199 */
200 rq_end_io_fn *end_io;
201 void *end_io_data;
202 };
203
204 /*
205 * first three bits match BIO_RW* bits, important
206 */
207 enum rq_flag_bits {
208 __REQ_RW, /* not set, read. set, write */
209 __REQ_FAILFAST, /* no low level driver retries */
210 __REQ_SORTED, /* elevator knows about this request */
211 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
212 __REQ_HARDBARRIER, /* may not be passed by drive either */
213 __REQ_FUA, /* forced unit access */
214 __REQ_CMD, /* is a regular fs rw request */
215 __REQ_NOMERGE, /* don't touch this for merging */
216 __REQ_STARTED, /* drive already may have started this one */
217 __REQ_DONTPREP, /* don't call prep for this one */
218 __REQ_QUEUED, /* uses queueing */
219 __REQ_ELVPRIV, /* elevator private data attached */
220 /*
221 * for ATA/ATAPI devices
222 */
223 __REQ_PC, /* packet command (special) */
224 __REQ_BLOCK_PC, /* queued down pc from block layer */
225 __REQ_SENSE, /* sense retrival */
226
227 __REQ_FAILED, /* set if the request failed */
228 __REQ_QUIET, /* don't worry about errors */
229 __REQ_SPECIAL, /* driver suplied command */
230 __REQ_DRIVE_CMD,
231 __REQ_DRIVE_TASK,
232 __REQ_DRIVE_TASKFILE,
233 __REQ_PREEMPT, /* set for "ide_preempt" requests */
234 __REQ_PM_SUSPEND, /* suspend request */
235 __REQ_PM_RESUME, /* resume request */
236 __REQ_PM_SHUTDOWN, /* shutdown request */
237 __REQ_ORDERED_COLOR, /* is before or after barrier */
238 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
239 __REQ_NR_BITS, /* stops here */
240 };
241
242 #define REQ_RW (1 << __REQ_RW)
243 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
244 #define REQ_SORTED (1 << __REQ_SORTED)
245 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
246 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
247 #define REQ_FUA (1 << __REQ_FUA)
248 #define REQ_CMD (1 << __REQ_CMD)
249 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
250 #define REQ_STARTED (1 << __REQ_STARTED)
251 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
252 #define REQ_QUEUED (1 << __REQ_QUEUED)
253 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
254 #define REQ_PC (1 << __REQ_PC)
255 #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
256 #define REQ_SENSE (1 << __REQ_SENSE)
257 #define REQ_FAILED (1 << __REQ_FAILED)
258 #define REQ_QUIET (1 << __REQ_QUIET)
259 #define REQ_SPECIAL (1 << __REQ_SPECIAL)
260 #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
261 #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
262 #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
263 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
264 #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
265 #define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
266 #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
267 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
268 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
269
270 /*
271 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
272 * requests. Some step values could eventually be made generic.
273 */
274 struct request_pm_state
275 {
276 /* PM state machine step value, currently driver specific */
277 int pm_step;
278 /* requested PM state value (S1, S2, S3, S4, ...) */
279 u32 pm_state;
280 void* data; /* for driver use */
281 };
282
283 #include <linux/elevator.h>
284
285 typedef int (merge_request_fn) (request_queue_t *, struct request *,
286 struct bio *);
287 typedef int (merge_requests_fn) (request_queue_t *, struct request *,
288 struct request *);
289 typedef void (request_fn_proc) (request_queue_t *q);
290 typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
291 typedef int (prep_rq_fn) (request_queue_t *, struct request *);
292 typedef void (unplug_fn) (request_queue_t *);
293
294 struct bio_vec;
295 typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
296 typedef void (activity_fn) (void *data, int rw);
297 typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
298 typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
299 typedef void (softirq_done_fn)(struct request *);
300
301 enum blk_queue_state {
302 Queue_down,
303 Queue_up,
304 };
305
306 struct blk_queue_tag {
307 struct request **tag_index; /* map of busy tags */
308 unsigned long *tag_map; /* bit map of free/busy tags */
309 struct list_head busy_list; /* fifo list of busy tags */
310 int busy; /* current depth */
311 int max_depth; /* what we will send to device */
312 int real_max_depth; /* what the array can hold */
313 atomic_t refcnt; /* map can be shared */
314 };
315
316 struct request_queue
317 {
318 /*
319 * Together with queue_head for cacheline sharing
320 */
321 struct list_head queue_head;
322 struct request *last_merge;
323 elevator_t *elevator;
324
325 /*
326 * the queue request freelist, one for reads and one for writes
327 */
328 struct request_list rq;
329
330 request_fn_proc *request_fn;
331 merge_request_fn *back_merge_fn;
332 merge_request_fn *front_merge_fn;
333 merge_requests_fn *merge_requests_fn;
334 make_request_fn *make_request_fn;
335 prep_rq_fn *prep_rq_fn;
336 unplug_fn *unplug_fn;
337 merge_bvec_fn *merge_bvec_fn;
338 activity_fn *activity_fn;
339 issue_flush_fn *issue_flush_fn;
340 prepare_flush_fn *prepare_flush_fn;
341 softirq_done_fn *softirq_done_fn;
342
343 /*
344 * Dispatch queue sorting
345 */
346 sector_t end_sector;
347 struct request *boundary_rq;
348
349 /*
350 * Auto-unplugging state
351 */
352 struct timer_list unplug_timer;
353 int unplug_thresh; /* After this many requests */
354 unsigned long unplug_delay; /* After this many jiffies */
355 struct work_struct unplug_work;
356
357 struct backing_dev_info backing_dev_info;
358
359 /*
360 * The queue owner gets to use this for whatever they like.
361 * ll_rw_blk doesn't touch it.
362 */
363 void *queuedata;
364
365 void *activity_data;
366
367 /*
368 * queue needs bounce pages for pages above this limit
369 */
370 unsigned long bounce_pfn;
371 gfp_t bounce_gfp;
372
373 /*
374 * various queue flags, see QUEUE_* below
375 */
376 unsigned long queue_flags;
377
378 /*
379 * protects queue structures from reentrancy. ->__queue_lock should
380 * _never_ be used directly, it is queue private. always use
381 * ->queue_lock.
382 */
383 spinlock_t __queue_lock;
384 spinlock_t *queue_lock;
385
386 /*
387 * queue kobject
388 */
389 struct kobject kobj;
390
391 /*
392 * queue settings
393 */
394 unsigned long nr_requests; /* Max # of requests */
395 unsigned int nr_congestion_on;
396 unsigned int nr_congestion_off;
397 unsigned int nr_batching;
398
399 unsigned int max_sectors;
400 unsigned int max_hw_sectors;
401 unsigned short max_phys_segments;
402 unsigned short max_hw_segments;
403 unsigned short hardsect_size;
404 unsigned int max_segment_size;
405
406 unsigned long seg_boundary_mask;
407 unsigned int dma_alignment;
408
409 struct blk_queue_tag *queue_tags;
410
411 unsigned int nr_sorted;
412 unsigned int in_flight;
413
414 /*
415 * sg stuff
416 */
417 unsigned int sg_timeout;
418 unsigned int sg_reserved_size;
419 int node;
420
421 struct blk_trace *blk_trace;
422
423 /*
424 * reserved for flush operations
425 */
426 unsigned int ordered, next_ordered, ordseq;
427 int orderr, ordcolor;
428 struct request pre_flush_rq, bar_rq, post_flush_rq;
429 struct request *orig_bar_rq;
430 unsigned int bi_size;
431
432 struct mutex sysfs_lock;
433 };
434
435 #define RQ_INACTIVE (-1)
436 #define RQ_ACTIVE 1
437
438 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
439 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
440 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
441 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
442 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
443 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
444 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
445 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
446 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
447
448 enum {
449 /*
450 * Hardbarrier is supported with one of the following methods.
451 *
452 * NONE : hardbarrier unsupported
453 * DRAIN : ordering by draining is enough
454 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
455 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
456 * TAG : ordering by tag is enough
457 * TAG_FLUSH : ordering by tag w/ pre and post flushes
458 * TAG_FUA : ordering by tag w/ pre flush and FUA write
459 */
460 QUEUE_ORDERED_NONE = 0x00,
461 QUEUE_ORDERED_DRAIN = 0x01,
462 QUEUE_ORDERED_TAG = 0x02,
463
464 QUEUE_ORDERED_PREFLUSH = 0x10,
465 QUEUE_ORDERED_POSTFLUSH = 0x20,
466 QUEUE_ORDERED_FUA = 0x40,
467
468 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
469 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
470 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
471 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
472 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
473 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
474 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
475 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
476
477 /*
478 * Ordered operation sequence
479 */
480 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
481 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
482 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
483 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
484 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
485 QUEUE_ORDSEQ_DONE = 0x20,
486 };
487
488 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
489 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
490 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
491 #define blk_queue_flushing(q) ((q)->ordseq)
492
493 #define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
494 #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
495 #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
496 #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
497
498 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
499
500 #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
501 #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
502 #define blk_pm_request(rq) \
503 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
504
505 #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
506 #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
507 #define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
508
509 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
510
511 #define rq_data_dir(rq) ((rq)->flags & 1)
512
blk_queue_full(struct request_queue * q,int rw)513 static inline int blk_queue_full(struct request_queue *q, int rw)
514 {
515 if (rw == READ)
516 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
517 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
518 }
519
blk_set_queue_full(struct request_queue * q,int rw)520 static inline void blk_set_queue_full(struct request_queue *q, int rw)
521 {
522 if (rw == READ)
523 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
524 else
525 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
526 }
527
blk_clear_queue_full(struct request_queue * q,int rw)528 static inline void blk_clear_queue_full(struct request_queue *q, int rw)
529 {
530 if (rw == READ)
531 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
532 else
533 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
534 }
535
536
537 /*
538 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
539 * it already be started by driver.
540 */
541 #define RQ_NOMERGE_FLAGS \
542 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
543 #define rq_mergeable(rq) \
544 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
545
546 /*
547 * noop, requests are automagically marked as active/inactive by I/O
548 * scheduler -- see elv_next_request
549 */
550 #define blk_queue_headactive(q, head_active)
551
552 /*
553 * q->prep_rq_fn return values
554 */
555 #define BLKPREP_OK 0 /* serve it */
556 #define BLKPREP_KILL 1 /* fatal error, kill */
557 #define BLKPREP_DEFER 2 /* leave on queue */
558
559 extern unsigned long blk_max_low_pfn, blk_max_pfn;
560
561 /*
562 * standard bounce addresses:
563 *
564 * BLK_BOUNCE_HIGH : bounce all highmem pages
565 * BLK_BOUNCE_ANY : don't bounce anything
566 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
567 */
568 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
569 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
570 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
571
572 #ifdef CONFIG_MMU
573 extern int init_emergency_isa_pool(void);
574 extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
575 #else
init_emergency_isa_pool(void)576 static inline int init_emergency_isa_pool(void)
577 {
578 return 0;
579 }
blk_queue_bounce(request_queue_t * q,struct bio ** bio)580 static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
581 {
582 }
583 #endif /* CONFIG_MMU */
584
585 #define rq_for_each_bio(_bio, rq) \
586 if ((rq->bio)) \
587 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
588
589 struct sec_size {
590 unsigned block_size;
591 unsigned block_size_bits;
592 };
593
594 extern int blk_register_queue(struct gendisk *disk);
595 extern void blk_unregister_queue(struct gendisk *disk);
596 extern void register_disk(struct gendisk *dev);
597 extern void generic_make_request(struct bio *bio);
598 extern void blk_put_request(struct request *);
599 extern void __blk_put_request(request_queue_t *, struct request *);
600 extern void blk_end_sync_rq(struct request *rq, int error);
601 extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
602 extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
603 extern void blk_requeue_request(request_queue_t *, struct request *);
604 extern void blk_plug_device(request_queue_t *);
605 extern int blk_remove_plug(request_queue_t *);
606 extern void blk_recount_segments(request_queue_t *, struct bio *);
607 extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
608 extern int sg_scsi_ioctl(struct file *, struct request_queue *,
609 struct gendisk *, struct scsi_ioctl_command __user *);
610 extern void blk_start_queue(request_queue_t *q);
611 extern void blk_stop_queue(request_queue_t *q);
612 extern void blk_sync_queue(struct request_queue *q);
613 extern void __blk_stop_queue(request_queue_t *q);
614 extern void blk_run_queue(request_queue_t *);
615 extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
616 extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
617 extern int blk_rq_unmap_user(struct bio *, unsigned int);
618 extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t);
619 extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
620 extern int blk_execute_rq(request_queue_t *, struct gendisk *,
621 struct request *, int);
622 extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *,
623 struct request *, int, rq_end_io_fn *);
624
bdev_get_queue(struct block_device * bdev)625 static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
626 {
627 return bdev->bd_disk->queue;
628 }
629
blk_run_backing_dev(struct backing_dev_info * bdi,struct page * page)630 static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
631 struct page *page)
632 {
633 if (bdi && bdi->unplug_io_fn)
634 bdi->unplug_io_fn(bdi, page);
635 }
636
blk_run_address_space(struct address_space * mapping)637 static inline void blk_run_address_space(struct address_space *mapping)
638 {
639 if (mapping)
640 blk_run_backing_dev(mapping->backing_dev_info, NULL);
641 }
642
643 /*
644 * end_request() and friends. Must be called with the request queue spinlock
645 * acquired. All functions called within end_request() _must_be_ atomic.
646 *
647 * Several drivers define their own end_request and call
648 * end_that_request_first() and end_that_request_last()
649 * for parts of the original function. This prevents
650 * code duplication in drivers.
651 */
652 extern int end_that_request_first(struct request *, int, int);
653 extern int end_that_request_chunk(struct request *, int, int);
654 extern void end_that_request_last(struct request *, int);
655 extern void end_request(struct request *req, int uptodate);
656 extern void blk_complete_request(struct request *);
657
rq_all_done(struct request * rq,unsigned int nr_bytes)658 static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
659 {
660 if (blk_fs_request(rq))
661 return (nr_bytes >= (rq->hard_nr_sectors << 9));
662 else if (blk_pc_request(rq))
663 return nr_bytes >= rq->data_len;
664
665 return 0;
666 }
667
668 /*
669 * end_that_request_first/chunk() takes an uptodate argument. we account
670 * any value <= as an io error. 0 means -EIO for compatability reasons,
671 * any other < 0 value is the direct error type. An uptodate value of
672 * 1 indicates successful io completion
673 */
674 #define end_io_error(uptodate) (unlikely((uptodate) <= 0))
675
blkdev_dequeue_request(struct request * req)676 static inline void blkdev_dequeue_request(struct request *req)
677 {
678 elv_dequeue_request(req->q, req);
679 }
680
681 /*
682 * This should be in elevator.h, but that requires pulling in rq and q
683 */
elv_dispatch_add_tail(struct request_queue * q,struct request * rq)684 static inline void elv_dispatch_add_tail(struct request_queue *q,
685 struct request *rq)
686 {
687 if (q->last_merge == rq)
688 q->last_merge = NULL;
689 q->nr_sorted--;
690
691 q->end_sector = rq_end_sector(rq);
692 q->boundary_rq = rq;
693 list_add_tail(&rq->queuelist, &q->queue_head);
694 }
695
696 /*
697 * Access functions for manipulating queue properties
698 */
699 extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
700 spinlock_t *lock, int node_id);
701 extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
702 extern void blk_cleanup_queue(request_queue_t *);
703 extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
704 extern void blk_queue_bounce_limit(request_queue_t *, u64);
705 extern void blk_queue_max_sectors(request_queue_t *, unsigned int);
706 extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
707 extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
708 extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
709 extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
710 extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
711 extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
712 extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
713 extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
714 extern void blk_queue_dma_alignment(request_queue_t *, int);
715 extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *);
716 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
717 extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *);
718 extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
719 extern int blk_do_ordered(request_queue_t *, struct request **);
720 extern unsigned blk_ordered_cur_seq(request_queue_t *);
721 extern unsigned blk_ordered_req_seq(struct request *);
722 extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int);
723
724 extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
725 extern void blk_dump_rq_flags(struct request *, char *);
726 extern void generic_unplug_device(request_queue_t *);
727 extern void __generic_unplug_device(request_queue_t *);
728 extern long nr_blockdev_pages(void);
729
730 int blk_get_queue(request_queue_t *);
731 request_queue_t *blk_alloc_queue(gfp_t);
732 request_queue_t *blk_alloc_queue_node(gfp_t, int);
733 extern void blk_put_queue(request_queue_t *);
734
735 /*
736 * tag stuff
737 */
738 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
739 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
740 #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
741 extern int blk_queue_start_tag(request_queue_t *, struct request *);
742 extern struct request *blk_queue_find_tag(request_queue_t *, int);
743 extern void blk_queue_end_tag(request_queue_t *, struct request *);
744 extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
745 extern void blk_queue_free_tags(request_queue_t *);
746 extern int blk_queue_resize_tags(request_queue_t *, int);
747 extern void blk_queue_invalidate_tags(request_queue_t *);
748 extern long blk_congestion_wait(int rw, long timeout);
749
750 extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
751 extern int blkdev_issue_flush(struct block_device *, sector_t *);
752
753 #define MAX_PHYS_SEGMENTS 128
754 #define MAX_HW_SEGMENTS 128
755 #define SAFE_MAX_SECTORS 255
756 #define BLK_DEF_MAX_SECTORS 1024
757
758 #define MAX_SEGMENT_SIZE 65536
759
760 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
761
queue_hardsect_size(request_queue_t * q)762 static inline int queue_hardsect_size(request_queue_t *q)
763 {
764 int retval = 512;
765
766 if (q && q->hardsect_size)
767 retval = q->hardsect_size;
768
769 return retval;
770 }
771
bdev_hardsect_size(struct block_device * bdev)772 static inline int bdev_hardsect_size(struct block_device *bdev)
773 {
774 return queue_hardsect_size(bdev_get_queue(bdev));
775 }
776
queue_dma_alignment(request_queue_t * q)777 static inline int queue_dma_alignment(request_queue_t *q)
778 {
779 int retval = 511;
780
781 if (q && q->dma_alignment)
782 retval = q->dma_alignment;
783
784 return retval;
785 }
786
bdev_dma_aligment(struct block_device * bdev)787 static inline int bdev_dma_aligment(struct block_device *bdev)
788 {
789 return queue_dma_alignment(bdev_get_queue(bdev));
790 }
791
792 #define blk_finished_io(nsects) do { } while (0)
793 #define blk_started_io(nsects) do { } while (0)
794
795 /* assumes size > 256 */
blksize_bits(unsigned int size)796 static inline unsigned int blksize_bits(unsigned int size)
797 {
798 unsigned int bits = 8;
799 do {
800 bits++;
801 size >>= 1;
802 } while (size > 256);
803 return bits;
804 }
805
block_size(struct block_device * bdev)806 static inline unsigned int block_size(struct block_device *bdev)
807 {
808 return bdev->bd_block_size;
809 }
810
811 typedef struct {struct page *v;} Sector;
812
813 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
814
put_dev_sector(Sector p)815 static inline void put_dev_sector(Sector p)
816 {
817 page_cache_release(p.v);
818 }
819
820 struct work_struct;
821 int kblockd_schedule_work(struct work_struct *work);
822 void kblockd_flush(void);
823
824 #ifdef CONFIG_LBD
825 # include <asm/div64.h>
826 # define sector_div(a, b) do_div(a, b)
827 #else
828 # define sector_div(n, b)( \
829 { \
830 int _res; \
831 _res = (n) % (b); \
832 (n) /= (b); \
833 _res; \
834 } \
835 )
836 #endif
837
838 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
839 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
840 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
841 MODULE_ALIAS("block-major-" __stringify(major) "-*")
842
843
844 #endif
845