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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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;
Jens Axboe2056a782006-03-23 20:00:26 +010025struct blk_trace;
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27#define BLKDEV_MIN_RQ 4
28#define BLKDEV_MAX_RQ 128 /* Default maximum */
29
30/*
31 * This is the per-process anticipatory I/O scheduler state.
32 */
33struct as_io_context {
34 spinlock_t lock;
35
36 void (*dtor)(struct as_io_context *aic); /* destructor */
37 void (*exit)(struct as_io_context *aic); /* called on task exit */
38
39 unsigned long state;
40 atomic_t nr_queued; /* queued reads & sync writes */
41 atomic_t nr_dispatched; /* number of requests gone to the drivers */
42
43 /* IO History tracking */
44 /* Thinktime */
45 unsigned long last_end_request;
46 unsigned long ttime_total;
47 unsigned long ttime_samples;
48 unsigned long ttime_mean;
49 /* Layout pattern */
50 unsigned int seek_samples;
51 sector_t last_request_pos;
52 u64 seek_total;
53 sector_t seek_mean;
54};
55
56struct cfq_queue;
57struct cfq_io_context {
Jens Axboee2d74ac2006-03-28 08:59:01 +020058 struct rb_node rb_node;
Jens Axboe22e2c502005-06-27 10:55:12 +020059 void *key;
60
Jens Axboee2d74ac2006-03-28 08:59:01 +020061 struct cfq_queue *cfqq[2];
62
Jens Axboe22e2c502005-06-27 10:55:12 +020063 struct io_context *ioc;
64
65 unsigned long last_end_request;
Jens Axboe206dc692006-03-28 13:03:44 +020066 sector_t last_request_pos;
67 unsigned long last_queue;
68
Jens Axboe22e2c502005-06-27 10:55:12 +020069 unsigned long ttime_total;
70 unsigned long ttime_samples;
71 unsigned long ttime_mean;
72
Jens Axboe206dc692006-03-28 13:03:44 +020073 unsigned int seek_samples;
74 u64 seek_total;
75 sector_t seek_mean;
76
Al Virod9ff4182006-03-18 13:51:22 -050077 struct list_head queue_list;
78
Jens Axboee2d74ac2006-03-28 08:59:01 +020079 void (*dtor)(struct io_context *); /* destructor */
80 void (*exit)(struct io_context *); /* called on task exit */
Linus Torvalds1da177e2005-04-16 15:20:36 -070081};
82
83/*
84 * This is the per-process I/O subsystem state. It is refcounted and
85 * kmalloc'ed. Currently all fields are modified in process io context
86 * (apart from the atomic refcount), so require no locking.
87 */
88struct io_context {
89 atomic_t refcount;
Jens Axboe22e2c502005-06-27 10:55:12 +020090 struct task_struct *task;
91
92 int (*set_ioprio)(struct io_context *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
94 /*
95 * For request batching
96 */
97 unsigned long last_waited; /* Time last woken after wait for request */
98 int nr_batch_requests; /* Number of requests left in the batch */
99
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 struct as_io_context *aic;
Jens Axboee2d74ac2006-03-28 08:59:01 +0200101 struct rb_root cic_root;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102};
103
104void put_io_context(struct io_context *ioc);
105void exit_io_context(void);
Al Viro8267e262005-10-21 03:20:53 -0400106struct io_context *current_io_context(gfp_t gfp_flags);
107struct io_context *get_io_context(gfp_t gfp_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108void copy_io_context(struct io_context **pdst, struct io_context **psrc);
109void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
110
111struct request;
Tejun Heo8ffdc652006-01-06 09:49:03 +0100112typedef void (rq_end_io_fn)(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
114struct request_list {
115 int count[2];
116 int starved[2];
Tejun Heocb98fc82005-10-28 08:29:39 +0200117 int elvpriv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 mempool_t *rq_pool;
119 wait_queue_head_t wait[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120};
121
122#define BLK_MAX_CDB 16
123
124/*
125 * try to put the fields that are referenced together in the same cacheline
126 */
127struct request {
Jens Axboeff856ba2006-01-09 16:02:34 +0100128 struct list_head queuelist;
129 struct list_head donelist;
130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 unsigned long flags; /* see REQ_ bits below */
132
133 /* Maintain bio traversal state for part by part I/O submission.
134 * hard_* are block layer internals, no driver should touch them!
135 */
136
137 sector_t sector; /* next sector to submit */
138 unsigned long nr_sectors; /* no. of sectors left to submit */
139 /* no. of sectors left to submit in the current segment */
140 unsigned int current_nr_sectors;
141
142 sector_t hard_sector; /* next sector to complete */
143 unsigned long hard_nr_sectors; /* no. of sectors left to complete */
144 /* no. of sectors left to complete in the current segment */
145 unsigned int hard_cur_sectors;
146
147 struct bio *bio;
148 struct bio *biotail;
149
150 void *elevator_private;
Jens Axboeff856ba2006-01-09 16:02:34 +0100151 void *completion_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Jens Axboe22e2c502005-06-27 10:55:12 +0200153 unsigned short ioprio;
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 int rq_status; /* should split this into a few status bits */
156 struct gendisk *rq_disk;
157 int errors;
158 unsigned long start_time;
159
160 /* Number of scatter-gather DMA addr+len pairs after
161 * physical address coalescing is performed.
162 */
163 unsigned short nr_phys_segments;
164
165 /* Number of scatter-gather addr+len pairs after
166 * physical and DMA remapping hardware coalescing is performed.
167 * This is the number of scatter-gather entries the driver
168 * will actually have to deal with after DMA mapping is done.
169 */
170 unsigned short nr_hw_segments;
171
172 int tag;
173 char *buffer;
174
175 int ref_count;
176 request_queue_t *q;
177 struct request_list *rl;
178
179 struct completion *waiting;
180 void *special;
181
182 /*
183 * when request is used as a packet command carrier
184 */
185 unsigned int cmd_len;
186 unsigned char cmd[BLK_MAX_CDB];
187
188 unsigned int data_len;
189 void *data;
190
191 unsigned int sense_len;
192 void *sense;
193
194 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600195 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
197 /*
198 * For Power Management requests
199 */
200 struct request_pm_state *pm;
201
202 /*
203 * completion callback. end_io_data should be folded in with waiting
204 */
205 rq_end_io_fn *end_io;
206 void *end_io_data;
207};
208
209/*
210 * first three bits match BIO_RW* bits, important
211 */
212enum rq_flag_bits {
213 __REQ_RW, /* not set, read. set, write */
214 __REQ_FAILFAST, /* no low level driver retries */
Tejun Heo8922e162005-10-20 16:23:44 +0200215 __REQ_SORTED, /* elevator knows about this request */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
217 __REQ_HARDBARRIER, /* may not be passed by drive either */
Tejun Heo797e7db2006-01-06 09:51:03 +0100218 __REQ_FUA, /* forced unit access */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 __REQ_CMD, /* is a regular fs rw request */
220 __REQ_NOMERGE, /* don't touch this for merging */
221 __REQ_STARTED, /* drive already may have started this one */
222 __REQ_DONTPREP, /* don't call prep for this one */
223 __REQ_QUEUED, /* uses queueing */
Tejun Heocb98fc82005-10-28 08:29:39 +0200224 __REQ_ELVPRIV, /* elevator private data attached */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 /*
226 * for ATA/ATAPI devices
227 */
228 __REQ_PC, /* packet command (special) */
229 __REQ_BLOCK_PC, /* queued down pc from block layer */
230 __REQ_SENSE, /* sense retrival */
231
232 __REQ_FAILED, /* set if the request failed */
233 __REQ_QUIET, /* don't worry about errors */
234 __REQ_SPECIAL, /* driver suplied command */
235 __REQ_DRIVE_CMD,
236 __REQ_DRIVE_TASK,
237 __REQ_DRIVE_TASKFILE,
238 __REQ_PREEMPT, /* set for "ide_preempt" requests */
239 __REQ_PM_SUSPEND, /* suspend request */
240 __REQ_PM_RESUME, /* resume request */
241 __REQ_PM_SHUTDOWN, /* shutdown request */
Tejun Heo797e7db2006-01-06 09:51:03 +0100242 __REQ_ORDERED_COLOR, /* is before or after barrier */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 __REQ_NR_BITS, /* stops here */
244};
245
246#define REQ_RW (1 << __REQ_RW)
247#define REQ_FAILFAST (1 << __REQ_FAILFAST)
Tejun Heo8922e162005-10-20 16:23:44 +0200248#define REQ_SORTED (1 << __REQ_SORTED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
250#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
Tejun Heo797e7db2006-01-06 09:51:03 +0100251#define REQ_FUA (1 << __REQ_FUA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252#define REQ_CMD (1 << __REQ_CMD)
253#define REQ_NOMERGE (1 << __REQ_NOMERGE)
254#define REQ_STARTED (1 << __REQ_STARTED)
255#define REQ_DONTPREP (1 << __REQ_DONTPREP)
256#define REQ_QUEUED (1 << __REQ_QUEUED)
Tejun Heocb98fc82005-10-28 08:29:39 +0200257#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258#define REQ_PC (1 << __REQ_PC)
259#define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
260#define REQ_SENSE (1 << __REQ_SENSE)
261#define REQ_FAILED (1 << __REQ_FAILED)
262#define REQ_QUIET (1 << __REQ_QUIET)
263#define REQ_SPECIAL (1 << __REQ_SPECIAL)
264#define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
265#define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
266#define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
267#define REQ_PREEMPT (1 << __REQ_PREEMPT)
268#define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
269#define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
270#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
Tejun Heo797e7db2006-01-06 09:51:03 +0100271#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273/*
274 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
275 * requests. Some step values could eventually be made generic.
276 */
277struct request_pm_state
278{
279 /* PM state machine step value, currently driver specific */
280 int pm_step;
281 /* requested PM state value (S1, S2, S3, S4, ...) */
282 u32 pm_state;
283 void* data; /* for driver use */
284};
285
286#include <linux/elevator.h>
287
288typedef int (merge_request_fn) (request_queue_t *, struct request *,
289 struct bio *);
290typedef int (merge_requests_fn) (request_queue_t *, struct request *,
291 struct request *);
292typedef void (request_fn_proc) (request_queue_t *q);
293typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
294typedef int (prep_rq_fn) (request_queue_t *, struct request *);
295typedef void (unplug_fn) (request_queue_t *);
296
297struct bio_vec;
298typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
299typedef void (activity_fn) (void *data, int rw);
300typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100301typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100302typedef void (softirq_done_fn)(struct request *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303
304enum blk_queue_state {
305 Queue_down,
306 Queue_up,
307};
308
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309struct blk_queue_tag {
310 struct request **tag_index; /* map of busy tags */
311 unsigned long *tag_map; /* bit map of free/busy tags */
312 struct list_head busy_list; /* fifo list of busy tags */
313 int busy; /* current depth */
314 int max_depth; /* what we will send to device */
Tejun Heoba025082005-08-05 13:28:11 -0700315 int real_max_depth; /* what the array can hold */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 atomic_t refcnt; /* map can be shared */
317};
318
319struct request_queue
320{
321 /*
322 * Together with queue_head for cacheline sharing
323 */
324 struct list_head queue_head;
325 struct request *last_merge;
326 elevator_t *elevator;
327
328 /*
329 * the queue request freelist, one for reads and one for writes
330 */
331 struct request_list rq;
332
333 request_fn_proc *request_fn;
334 merge_request_fn *back_merge_fn;
335 merge_request_fn *front_merge_fn;
336 merge_requests_fn *merge_requests_fn;
337 make_request_fn *make_request_fn;
338 prep_rq_fn *prep_rq_fn;
339 unplug_fn *unplug_fn;
340 merge_bvec_fn *merge_bvec_fn;
341 activity_fn *activity_fn;
342 issue_flush_fn *issue_flush_fn;
343 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100344 softirq_done_fn *softirq_done_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200347 * Dispatch queue sorting
348 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200349 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200350 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200351
352 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 * Auto-unplugging state
354 */
355 struct timer_list unplug_timer;
356 int unplug_thresh; /* After this many requests */
357 unsigned long unplug_delay; /* After this many jiffies */
358 struct work_struct unplug_work;
359
360 struct backing_dev_info backing_dev_info;
361
362 /*
363 * The queue owner gets to use this for whatever they like.
364 * ll_rw_blk doesn't touch it.
365 */
366 void *queuedata;
367
368 void *activity_data;
369
370 /*
371 * queue needs bounce pages for pages above this limit
372 */
373 unsigned long bounce_pfn;
Al Viro8267e262005-10-21 03:20:53 -0400374 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
376 /*
377 * various queue flags, see QUEUE_* below
378 */
379 unsigned long queue_flags;
380
381 /*
152587d2005-04-12 16:22:06 -0500382 * protects queue structures from reentrancy. ->__queue_lock should
383 * _never_ be used directly, it is queue private. always use
384 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 */
152587d2005-04-12 16:22:06 -0500386 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 spinlock_t *queue_lock;
388
389 /*
390 * queue kobject
391 */
392 struct kobject kobj;
393
394 /*
395 * queue settings
396 */
397 unsigned long nr_requests; /* Max # of requests */
398 unsigned int nr_congestion_on;
399 unsigned int nr_congestion_off;
400 unsigned int nr_batching;
401
Jens Axboe2cb2e142006-01-17 09:04:32 +0100402 unsigned int max_sectors;
403 unsigned int max_hw_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 unsigned short max_phys_segments;
405 unsigned short max_hw_segments;
406 unsigned short hardsect_size;
407 unsigned int max_segment_size;
408
409 unsigned long seg_boundary_mask;
410 unsigned int dma_alignment;
411
412 struct blk_queue_tag *queue_tags;
413
Tejun Heo15853af2005-11-10 08:52:05 +0100414 unsigned int nr_sorted;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 unsigned int in_flight;
416
417 /*
418 * sg stuff
419 */
420 unsigned int sg_timeout;
421 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700422 int node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423
Jens Axboe2056a782006-03-23 20:00:26 +0100424 struct blk_trace *blk_trace;
425
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 /*
427 * reserved for flush operations
428 */
Tejun Heo797e7db2006-01-06 09:51:03 +0100429 unsigned int ordered, next_ordered, ordseq;
430 int orderr, ordcolor;
431 struct request pre_flush_rq, bar_rq, post_flush_rq;
432 struct request *orig_bar_rq;
433 unsigned int bi_size;
Al Viro483f4af2006-03-18 18:34:37 -0500434
435 struct mutex sysfs_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436};
437
438#define RQ_INACTIVE (-1)
439#define RQ_ACTIVE 1
440#define RQ_SCSI_BUSY 0xffff
441#define RQ_SCSI_DONE 0xfffe
442#define RQ_SCSI_DISCONNECTING 0xffe0
443
444#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
445#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
446#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
447#define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
448#define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
449#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
450#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
451#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200452#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
Tejun Heo797e7db2006-01-06 09:51:03 +0100453
454enum {
455 /*
456 * Hardbarrier is supported with one of the following methods.
457 *
458 * NONE : hardbarrier unsupported
459 * DRAIN : ordering by draining is enough
460 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
461 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
462 * TAG : ordering by tag is enough
463 * TAG_FLUSH : ordering by tag w/ pre and post flushes
464 * TAG_FUA : ordering by tag w/ pre flush and FUA write
465 */
466 QUEUE_ORDERED_NONE = 0x00,
467 QUEUE_ORDERED_DRAIN = 0x01,
468 QUEUE_ORDERED_TAG = 0x02,
469
470 QUEUE_ORDERED_PREFLUSH = 0x10,
471 QUEUE_ORDERED_POSTFLUSH = 0x20,
472 QUEUE_ORDERED_FUA = 0x40,
473
474 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
475 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
476 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
477 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
478 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
479 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
480 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
481 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
482
483 /*
484 * Ordered operation sequence
485 */
486 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
487 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
488 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
489 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
490 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
491 QUEUE_ORDSEQ_DONE = 0x20,
492};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
494#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
495#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
496#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100497#define blk_queue_flushing(q) ((q)->ordseq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
499#define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
500#define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
501#define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
502#define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
503
504#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
505
506#define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
507#define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
508#define blk_pm_request(rq) \
509 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
510
Tejun Heo8922e162005-10-20 16:23:44 +0200511#define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512#define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
Tejun Heo797e7db2006-01-06 09:51:03 +0100513#define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
515#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
516
517#define rq_data_dir(rq) ((rq)->flags & 1)
518
519static inline int blk_queue_full(struct request_queue *q, int rw)
520{
521 if (rw == READ)
522 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
523 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
524}
525
526static inline void blk_set_queue_full(struct request_queue *q, int rw)
527{
528 if (rw == READ)
529 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
530 else
531 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
532}
533
534static inline void blk_clear_queue_full(struct request_queue *q, int rw)
535{
536 if (rw == READ)
537 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
538 else
539 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
540}
541
542
543/*
544 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
545 * it already be started by driver.
546 */
547#define RQ_NOMERGE_FLAGS \
548 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
549#define rq_mergeable(rq) \
550 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
551
552/*
553 * noop, requests are automagically marked as active/inactive by I/O
554 * scheduler -- see elv_next_request
555 */
556#define blk_queue_headactive(q, head_active)
557
558/*
559 * q->prep_rq_fn return values
560 */
561#define BLKPREP_OK 0 /* serve it */
562#define BLKPREP_KILL 1 /* fatal error, kill */
563#define BLKPREP_DEFER 2 /* leave on queue */
564
565extern unsigned long blk_max_low_pfn, blk_max_pfn;
566
567/*
568 * standard bounce addresses:
569 *
570 * BLK_BOUNCE_HIGH : bounce all highmem pages
571 * BLK_BOUNCE_ANY : don't bounce anything
572 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
573 */
574#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
575#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
576#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
577
578#ifdef CONFIG_MMU
579extern int init_emergency_isa_pool(void);
580extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
581#else
582static inline int init_emergency_isa_pool(void)
583{
584 return 0;
585}
586static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
587{
588}
589#endif /* CONFIG_MMU */
590
591#define rq_for_each_bio(_bio, rq) \
592 if ((rq->bio)) \
593 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
594
595struct sec_size {
596 unsigned block_size;
597 unsigned block_size_bits;
598};
599
600extern int blk_register_queue(struct gendisk *disk);
601extern void blk_unregister_queue(struct gendisk *disk);
602extern void register_disk(struct gendisk *dev);
603extern void generic_make_request(struct bio *bio);
604extern void blk_put_request(struct request *);
Mike Christie6e39b692005-11-11 05:30:24 -0600605extern void __blk_put_request(request_queue_t *, struct request *);
Tejun Heo8ffdc652006-01-06 09:49:03 +0100606extern void blk_end_sync_rq(struct request *rq, int error);
Al Viro8267e262005-10-21 03:20:53 -0400607extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
Tejun Heo 867d1192005-04-24 02:06:05 -0500608extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609extern void blk_requeue_request(request_queue_t *, struct request *);
610extern void blk_plug_device(request_queue_t *);
611extern int blk_remove_plug(request_queue_t *);
612extern void blk_recount_segments(request_queue_t *, struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
614extern void blk_start_queue(request_queue_t *q);
615extern void blk_stop_queue(request_queue_t *q);
616extern void blk_sync_queue(struct request_queue *q);
617extern void __blk_stop_queue(request_queue_t *q);
618extern void blk_run_queue(request_queue_t *);
619extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
Jens Axboedd1cab92005-06-20 14:06:01 +0200620extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
621extern int blk_rq_unmap_user(struct bio *, unsigned int);
Al Viro8267e262005-10-21 03:20:53 -0400622extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t);
James Bottomley f1970ba2005-06-20 14:06:52 +0200623extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
James Bottomley 994ca9a2005-06-20 14:11:09 +0200624extern int blk_execute_rq(request_queue_t *, struct gendisk *,
625 struct request *, int);
Mike Christie6e39b692005-11-11 05:30:24 -0600626extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100627 struct request *, int, rq_end_io_fn *);
Mike Christie6e39b692005-11-11 05:30:24 -0600628
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
630{
631 return bdev->bd_disk->queue;
632}
633
634static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
635 struct page *page)
636{
637 if (bdi && bdi->unplug_io_fn)
638 bdi->unplug_io_fn(bdi, page);
639}
640
641static inline void blk_run_address_space(struct address_space *mapping)
642{
643 if (mapping)
644 blk_run_backing_dev(mapping->backing_dev_info, NULL);
645}
646
647/*
648 * end_request() and friends. Must be called with the request queue spinlock
649 * acquired. All functions called within end_request() _must_be_ atomic.
650 *
651 * Several drivers define their own end_request and call
652 * end_that_request_first() and end_that_request_last()
653 * for parts of the original function. This prevents
654 * code duplication in drivers.
655 */
656extern int end_that_request_first(struct request *, int, int);
657extern int end_that_request_chunk(struct request *, int, int);
Tejun Heo8ffdc652006-01-06 09:49:03 +0100658extern void end_that_request_last(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659extern void end_request(struct request *req, int uptodate);
Jens Axboeff856ba2006-01-09 16:02:34 +0100660extern void blk_complete_request(struct request *);
661
662static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
663{
664 if (blk_fs_request(rq))
665 return (nr_bytes >= (rq->hard_nr_sectors << 9));
666 else if (blk_pc_request(rq))
667 return nr_bytes >= rq->data_len;
668
669 return 0;
670}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
672/*
673 * end_that_request_first/chunk() takes an uptodate argument. we account
674 * any value <= as an io error. 0 means -EIO for compatability reasons,
675 * any other < 0 value is the direct error type. An uptodate value of
676 * 1 indicates successful io completion
677 */
678#define end_io_error(uptodate) (unlikely((uptodate) <= 0))
679
680static inline void blkdev_dequeue_request(struct request *req)
681{
Tejun Heo8922e162005-10-20 16:23:44 +0200682 elv_dequeue_request(req->q, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685/*
Jens Axboe1b47f532005-10-20 16:37:00 +0200686 * This should be in elevator.h, but that requires pulling in rq and q
687 */
688static inline void elv_dispatch_add_tail(struct request_queue *q,
689 struct request *rq)
690{
Tejun Heo06b86242005-10-20 16:46:23 +0200691 if (q->last_merge == rq)
692 q->last_merge = NULL;
Tejun Heo15853af2005-11-10 08:52:05 +0100693 q->nr_sorted--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
Jens Axboe1b47f532005-10-20 16:37:00 +0200695 q->end_sector = rq_end_sector(rq);
696 q->boundary_rq = rq;
697 list_add_tail(&rq->queuelist, &q->queue_head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698}
699
700/*
701 * Access functions for manipulating queue properties
702 */
Christoph Lameter19460892005-06-23 00:08:19 -0700703extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
704 spinlock_t *lock, int node_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
706extern void blk_cleanup_queue(request_queue_t *);
707extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
708extern void blk_queue_bounce_limit(request_queue_t *, u64);
Jens Axboe2cb2e142006-01-17 09:04:32 +0100709extern void blk_queue_max_sectors(request_queue_t *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
711extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
712extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
713extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
714extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
715extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
716extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
717extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
718extern void blk_queue_dma_alignment(request_queue_t *, int);
Jens Axboeff856ba2006-01-09 16:02:34 +0100719extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Tejun Heo797e7db2006-01-06 09:51:03 +0100721extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100723extern int blk_do_ordered(request_queue_t *, struct request **);
724extern unsigned blk_ordered_cur_seq(request_queue_t *);
725extern unsigned blk_ordered_req_seq(struct request *);
726extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727
728extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
729extern void blk_dump_rq_flags(struct request *, char *);
730extern void generic_unplug_device(request_queue_t *);
731extern void __generic_unplug_device(request_queue_t *);
732extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733
734int blk_get_queue(request_queue_t *);
Al Viro8267e262005-10-21 03:20:53 -0400735request_queue_t *blk_alloc_queue(gfp_t);
736request_queue_t *blk_alloc_queue_node(gfp_t, int);
Al Viro483f4af2006-03-18 18:34:37 -0500737extern void blk_put_queue(request_queue_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
739/*
740 * tag stuff
741 */
742#define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
743#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
744#define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
745extern int blk_queue_start_tag(request_queue_t *, struct request *);
746extern struct request *blk_queue_find_tag(request_queue_t *, int);
747extern void blk_queue_end_tag(request_queue_t *, struct request *);
748extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
749extern void blk_queue_free_tags(request_queue_t *);
750extern int blk_queue_resize_tags(request_queue_t *, int);
751extern void blk_queue_invalidate_tags(request_queue_t *);
752extern long blk_congestion_wait(int rw, long timeout);
753
754extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
755extern int blkdev_issue_flush(struct block_device *, sector_t *);
756
757#define MAX_PHYS_SEGMENTS 128
758#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -0600759#define SAFE_MAX_SECTORS 255
760#define BLK_DEF_MAX_SECTORS 1024
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761
762#define MAX_SEGMENT_SIZE 65536
763
764#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
765
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766static inline int queue_hardsect_size(request_queue_t *q)
767{
768 int retval = 512;
769
770 if (q && q->hardsect_size)
771 retval = q->hardsect_size;
772
773 return retval;
774}
775
776static inline int bdev_hardsect_size(struct block_device *bdev)
777{
778 return queue_hardsect_size(bdev_get_queue(bdev));
779}
780
781static inline int queue_dma_alignment(request_queue_t *q)
782{
783 int retval = 511;
784
785 if (q && q->dma_alignment)
786 retval = q->dma_alignment;
787
788 return retval;
789}
790
791static inline int bdev_dma_aligment(struct block_device *bdev)
792{
793 return queue_dma_alignment(bdev_get_queue(bdev));
794}
795
796#define blk_finished_io(nsects) do { } while (0)
797#define blk_started_io(nsects) do { } while (0)
798
799/* assumes size > 256 */
800static inline unsigned int blksize_bits(unsigned int size)
801{
802 unsigned int bits = 8;
803 do {
804 bits++;
805 size >>= 1;
806 } while (size > 256);
807 return bits;
808}
809
Adrian Bunk2befb9e2005-09-10 00:27:17 -0700810static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811{
812 return bdev->bd_block_size;
813}
814
815typedef struct {struct page *v;} Sector;
816
817unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
818
819static inline void put_dev_sector(Sector p)
820{
821 page_cache_release(p.v);
822}
823
824struct work_struct;
825int kblockd_schedule_work(struct work_struct *work);
826void kblockd_flush(void);
827
828#ifdef CONFIG_LBD
829# include <asm/div64.h>
830# define sector_div(a, b) do_div(a, b)
831#else
832# define sector_div(n, b)( \
833{ \
834 int _res; \
835 _res = (n) % (b); \
836 (n) /= (b); \
837 _res; \
838} \
839)
840#endif
841
842#define MODULE_ALIAS_BLOCKDEV(major,minor) \
843 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
844#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
845 MODULE_ALIAS("block-major-" __stringify(major) "-*")
846
847
848#endif