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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
Christoph Hellwig21b2f0c2006-03-22 17:52:04 +010020struct scsi_ioctl_command;
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022struct request_queue;
23typedef struct request_queue request_queue_t;
24struct elevator_queue;
25typedef struct elevator_queue elevator_t;
26struct request_pm_state;
Jens Axboe2056a782006-03-23 20:00:26 +010027struct blk_trace;
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29#define BLKDEV_MIN_RQ 4
30#define BLKDEV_MAX_RQ 128 /* Default maximum */
31
32/*
33 * This is the per-process anticipatory I/O scheduler state.
34 */
35struct as_io_context {
36 spinlock_t lock;
37
38 void (*dtor)(struct as_io_context *aic); /* destructor */
39 void (*exit)(struct as_io_context *aic); /* called on task exit */
40
41 unsigned long state;
42 atomic_t nr_queued; /* queued reads & sync writes */
43 atomic_t nr_dispatched; /* number of requests gone to the drivers */
44
45 /* IO History tracking */
46 /* Thinktime */
47 unsigned long last_end_request;
48 unsigned long ttime_total;
49 unsigned long ttime_samples;
50 unsigned long ttime_mean;
51 /* Layout pattern */
52 unsigned int seek_samples;
53 sector_t last_request_pos;
54 u64 seek_total;
55 sector_t seek_mean;
56};
57
58struct cfq_queue;
59struct cfq_io_context {
Jens Axboee2d74ac2006-03-28 08:59:01 +020060 struct rb_node rb_node;
Jens Axboe22e2c502005-06-27 10:55:12 +020061 void *key;
62
Jens Axboee2d74ac2006-03-28 08:59:01 +020063 struct cfq_queue *cfqq[2];
64
Jens Axboe22e2c502005-06-27 10:55:12 +020065 struct io_context *ioc;
66
67 unsigned long last_end_request;
Jens Axboe206dc692006-03-28 13:03:44 +020068 sector_t last_request_pos;
69 unsigned long last_queue;
70
Jens Axboe22e2c502005-06-27 10:55:12 +020071 unsigned long ttime_total;
72 unsigned long ttime_samples;
73 unsigned long ttime_mean;
74
Jens Axboe206dc692006-03-28 13:03:44 +020075 unsigned int seek_samples;
76 u64 seek_total;
77 sector_t seek_mean;
78
Al Virod9ff4182006-03-18 13:51:22 -050079 struct list_head queue_list;
80
Jens Axboee2d74ac2006-03-28 08:59:01 +020081 void (*dtor)(struct io_context *); /* destructor */
82 void (*exit)(struct io_context *); /* called on task exit */
Linus Torvalds1da177e2005-04-16 15:20:36 -070083};
84
85/*
86 * This is the per-process I/O subsystem state. It is refcounted and
87 * kmalloc'ed. Currently all fields are modified in process io context
88 * (apart from the atomic refcount), so require no locking.
89 */
90struct io_context {
91 atomic_t refcount;
Jens Axboe22e2c502005-06-27 10:55:12 +020092 struct task_struct *task;
93
94 int (*set_ioprio)(struct io_context *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 /*
97 * For request batching
98 */
99 unsigned long last_waited; /* Time last woken after wait for request */
100 int nr_batch_requests; /* Number of requests left in the batch */
101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 struct as_io_context *aic;
Jens Axboee2d74ac2006-03-28 08:59:01 +0200103 struct rb_root cic_root;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104};
105
106void put_io_context(struct io_context *ioc);
107void exit_io_context(void);
Al Viro8267e262005-10-21 03:20:53 -0400108struct io_context *current_io_context(gfp_t gfp_flags);
109struct io_context *get_io_context(gfp_t gfp_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110void copy_io_context(struct io_context **pdst, struct io_context **psrc);
111void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
112
113struct request;
Tejun Heo8ffdc652006-01-06 09:49:03 +0100114typedef void (rq_end_io_fn)(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
116struct request_list {
117 int count[2];
118 int starved[2];
Tejun Heocb98fc82005-10-28 08:29:39 +0200119 int elvpriv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 mempool_t *rq_pool;
121 wait_queue_head_t wait[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122};
123
124#define BLK_MAX_CDB 16
125
126/*
127 * try to put the fields that are referenced together in the same cacheline
128 */
129struct request {
Jens Axboeff856ba2006-01-09 16:02:34 +0100130 struct list_head queuelist;
131 struct list_head donelist;
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 unsigned long flags; /* see REQ_ bits below */
134
135 /* Maintain bio traversal state for part by part I/O submission.
136 * hard_* are block layer internals, no driver should touch them!
137 */
138
139 sector_t sector; /* next sector to submit */
140 unsigned long nr_sectors; /* no. of sectors left to submit */
141 /* no. of sectors left to submit in the current segment */
142 unsigned int current_nr_sectors;
143
144 sector_t hard_sector; /* next sector to complete */
145 unsigned long hard_nr_sectors; /* no. of sectors left to complete */
146 /* no. of sectors left to complete in the current segment */
147 unsigned int hard_cur_sectors;
148
149 struct bio *bio;
150 struct bio *biotail;
151
152 void *elevator_private;
Jens Axboeff856ba2006-01-09 16:02:34 +0100153 void *completion_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
Jens Axboe22e2c502005-06-27 10:55:12 +0200155 unsigned short ioprio;
156
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 int rq_status; /* should split this into a few status bits */
158 struct gendisk *rq_disk;
159 int errors;
160 unsigned long start_time;
161
162 /* Number of scatter-gather DMA addr+len pairs after
163 * physical address coalescing is performed.
164 */
165 unsigned short nr_phys_segments;
166
167 /* Number of scatter-gather addr+len pairs after
168 * physical and DMA remapping hardware coalescing is performed.
169 * This is the number of scatter-gather entries the driver
170 * will actually have to deal with after DMA mapping is done.
171 */
172 unsigned short nr_hw_segments;
173
174 int tag;
175 char *buffer;
176
177 int ref_count;
178 request_queue_t *q;
179 struct request_list *rl;
180
181 struct completion *waiting;
182 void *special;
183
184 /*
185 * when request is used as a packet command carrier
186 */
187 unsigned int cmd_len;
188 unsigned char cmd[BLK_MAX_CDB];
189
190 unsigned int data_len;
191 void *data;
192
193 unsigned int sense_len;
194 void *sense;
195
196 unsigned int timeout;
Mike Christie17e01f22005-11-11 05:31:37 -0600197 int retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199 /*
200 * For Power Management requests
201 */
202 struct request_pm_state *pm;
203
204 /*
205 * completion callback. end_io_data should be folded in with waiting
206 */
207 rq_end_io_fn *end_io;
208 void *end_io_data;
209};
210
211/*
212 * first three bits match BIO_RW* bits, important
213 */
214enum rq_flag_bits {
215 __REQ_RW, /* not set, read. set, write */
216 __REQ_FAILFAST, /* no low level driver retries */
Tejun Heo8922e162005-10-20 16:23:44 +0200217 __REQ_SORTED, /* elevator knows about this request */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
219 __REQ_HARDBARRIER, /* may not be passed by drive either */
Tejun Heo797e7db2006-01-06 09:51:03 +0100220 __REQ_FUA, /* forced unit access */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 __REQ_CMD, /* is a regular fs rw request */
222 __REQ_NOMERGE, /* don't touch this for merging */
223 __REQ_STARTED, /* drive already may have started this one */
224 __REQ_DONTPREP, /* don't call prep for this one */
225 __REQ_QUEUED, /* uses queueing */
Tejun Heocb98fc82005-10-28 08:29:39 +0200226 __REQ_ELVPRIV, /* elevator private data attached */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 /*
228 * for ATA/ATAPI devices
229 */
230 __REQ_PC, /* packet command (special) */
231 __REQ_BLOCK_PC, /* queued down pc from block layer */
232 __REQ_SENSE, /* sense retrival */
233
234 __REQ_FAILED, /* set if the request failed */
235 __REQ_QUIET, /* don't worry about errors */
236 __REQ_SPECIAL, /* driver suplied command */
237 __REQ_DRIVE_CMD,
238 __REQ_DRIVE_TASK,
239 __REQ_DRIVE_TASKFILE,
240 __REQ_PREEMPT, /* set for "ide_preempt" requests */
241 __REQ_PM_SUSPEND, /* suspend request */
242 __REQ_PM_RESUME, /* resume request */
243 __REQ_PM_SHUTDOWN, /* shutdown request */
Tejun Heo797e7db2006-01-06 09:51:03 +0100244 __REQ_ORDERED_COLOR, /* is before or after barrier */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 __REQ_NR_BITS, /* stops here */
246};
247
248#define REQ_RW (1 << __REQ_RW)
249#define REQ_FAILFAST (1 << __REQ_FAILFAST)
Tejun Heo8922e162005-10-20 16:23:44 +0200250#define REQ_SORTED (1 << __REQ_SORTED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
252#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
Tejun Heo797e7db2006-01-06 09:51:03 +0100253#define REQ_FUA (1 << __REQ_FUA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254#define REQ_CMD (1 << __REQ_CMD)
255#define REQ_NOMERGE (1 << __REQ_NOMERGE)
256#define REQ_STARTED (1 << __REQ_STARTED)
257#define REQ_DONTPREP (1 << __REQ_DONTPREP)
258#define REQ_QUEUED (1 << __REQ_QUEUED)
Tejun Heocb98fc82005-10-28 08:29:39 +0200259#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260#define REQ_PC (1 << __REQ_PC)
261#define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
262#define REQ_SENSE (1 << __REQ_SENSE)
263#define REQ_FAILED (1 << __REQ_FAILED)
264#define REQ_QUIET (1 << __REQ_QUIET)
265#define REQ_SPECIAL (1 << __REQ_SPECIAL)
266#define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
267#define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
268#define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
269#define REQ_PREEMPT (1 << __REQ_PREEMPT)
270#define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
271#define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
272#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
Tejun Heo797e7db2006-01-06 09:51:03 +0100273#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275/*
276 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
277 * requests. Some step values could eventually be made generic.
278 */
279struct request_pm_state
280{
281 /* PM state machine step value, currently driver specific */
282 int pm_step;
283 /* requested PM state value (S1, S2, S3, S4, ...) */
284 u32 pm_state;
285 void* data; /* for driver use */
286};
287
288#include <linux/elevator.h>
289
290typedef int (merge_request_fn) (request_queue_t *, struct request *,
291 struct bio *);
292typedef int (merge_requests_fn) (request_queue_t *, struct request *,
293 struct request *);
294typedef void (request_fn_proc) (request_queue_t *q);
295typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
296typedef int (prep_rq_fn) (request_queue_t *, struct request *);
297typedef void (unplug_fn) (request_queue_t *);
298
299struct bio_vec;
300typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
301typedef void (activity_fn) (void *data, int rw);
302typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100303typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
Jens Axboeff856ba2006-01-09 16:02:34 +0100304typedef void (softirq_done_fn)(struct request *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
306enum blk_queue_state {
307 Queue_down,
308 Queue_up,
309};
310
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311struct blk_queue_tag {
312 struct request **tag_index; /* map of busy tags */
313 unsigned long *tag_map; /* bit map of free/busy tags */
314 struct list_head busy_list; /* fifo list of busy tags */
315 int busy; /* current depth */
316 int max_depth; /* what we will send to device */
Tejun Heoba025082005-08-05 13:28:11 -0700317 int real_max_depth; /* what the array can hold */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 atomic_t refcnt; /* map can be shared */
319};
320
321struct request_queue
322{
323 /*
324 * Together with queue_head for cacheline sharing
325 */
326 struct list_head queue_head;
327 struct request *last_merge;
328 elevator_t *elevator;
329
330 /*
331 * the queue request freelist, one for reads and one for writes
332 */
333 struct request_list rq;
334
335 request_fn_proc *request_fn;
336 merge_request_fn *back_merge_fn;
337 merge_request_fn *front_merge_fn;
338 merge_requests_fn *merge_requests_fn;
339 make_request_fn *make_request_fn;
340 prep_rq_fn *prep_rq_fn;
341 unplug_fn *unplug_fn;
342 merge_bvec_fn *merge_bvec_fn;
343 activity_fn *activity_fn;
344 issue_flush_fn *issue_flush_fn;
345 prepare_flush_fn *prepare_flush_fn;
Jens Axboeff856ba2006-01-09 16:02:34 +0100346 softirq_done_fn *softirq_done_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
348 /*
Tejun Heo8922e162005-10-20 16:23:44 +0200349 * Dispatch queue sorting
350 */
Jens Axboe1b47f532005-10-20 16:37:00 +0200351 sector_t end_sector;
Tejun Heo8922e162005-10-20 16:23:44 +0200352 struct request *boundary_rq;
Tejun Heo8922e162005-10-20 16:23:44 +0200353
354 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 * Auto-unplugging state
356 */
357 struct timer_list unplug_timer;
358 int unplug_thresh; /* After this many requests */
359 unsigned long unplug_delay; /* After this many jiffies */
360 struct work_struct unplug_work;
361
362 struct backing_dev_info backing_dev_info;
363
364 /*
365 * The queue owner gets to use this for whatever they like.
366 * ll_rw_blk doesn't touch it.
367 */
368 void *queuedata;
369
370 void *activity_data;
371
372 /*
373 * queue needs bounce pages for pages above this limit
374 */
375 unsigned long bounce_pfn;
Al Viro8267e262005-10-21 03:20:53 -0400376 gfp_t bounce_gfp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
378 /*
379 * various queue flags, see QUEUE_* below
380 */
381 unsigned long queue_flags;
382
383 /*
152587d2005-04-12 16:22:06 -0500384 * protects queue structures from reentrancy. ->__queue_lock should
385 * _never_ be used directly, it is queue private. always use
386 * ->queue_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 */
152587d2005-04-12 16:22:06 -0500388 spinlock_t __queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 spinlock_t *queue_lock;
390
391 /*
392 * queue kobject
393 */
394 struct kobject kobj;
395
396 /*
397 * queue settings
398 */
399 unsigned long nr_requests; /* Max # of requests */
400 unsigned int nr_congestion_on;
401 unsigned int nr_congestion_off;
402 unsigned int nr_batching;
403
Jens Axboe2cb2e142006-01-17 09:04:32 +0100404 unsigned int max_sectors;
405 unsigned int max_hw_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 unsigned short max_phys_segments;
407 unsigned short max_hw_segments;
408 unsigned short hardsect_size;
409 unsigned int max_segment_size;
410
411 unsigned long seg_boundary_mask;
412 unsigned int dma_alignment;
413
414 struct blk_queue_tag *queue_tags;
415
Tejun Heo15853af2005-11-10 08:52:05 +0100416 unsigned int nr_sorted;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 unsigned int in_flight;
418
419 /*
420 * sg stuff
421 */
422 unsigned int sg_timeout;
423 unsigned int sg_reserved_size;
Christoph Lameter19460892005-06-23 00:08:19 -0700424 int node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
Jens Axboe2056a782006-03-23 20:00:26 +0100426 struct blk_trace *blk_trace;
427
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 /*
429 * reserved for flush operations
430 */
Tejun Heo797e7db2006-01-06 09:51:03 +0100431 unsigned int ordered, next_ordered, ordseq;
432 int orderr, ordcolor;
433 struct request pre_flush_rq, bar_rq, post_flush_rq;
434 struct request *orig_bar_rq;
435 unsigned int bi_size;
Al Viro483f4af2006-03-18 18:34:37 -0500436
437 struct mutex sysfs_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438};
439
440#define RQ_INACTIVE (-1)
441#define RQ_ACTIVE 1
442#define RQ_SCSI_BUSY 0xffff
443#define RQ_SCSI_DONE 0xfffe
444#define RQ_SCSI_DISCONNECTING 0xffe0
445
446#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
447#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
448#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
449#define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
450#define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
451#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
452#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
453#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
Jens Axboe64521d12005-10-28 08:30:39 +0200454#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
Tejun Heo797e7db2006-01-06 09:51:03 +0100455
456enum {
457 /*
458 * Hardbarrier is supported with one of the following methods.
459 *
460 * NONE : hardbarrier unsupported
461 * DRAIN : ordering by draining is enough
462 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
463 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
464 * TAG : ordering by tag is enough
465 * TAG_FLUSH : ordering by tag w/ pre and post flushes
466 * TAG_FUA : ordering by tag w/ pre flush and FUA write
467 */
468 QUEUE_ORDERED_NONE = 0x00,
469 QUEUE_ORDERED_DRAIN = 0x01,
470 QUEUE_ORDERED_TAG = 0x02,
471
472 QUEUE_ORDERED_PREFLUSH = 0x10,
473 QUEUE_ORDERED_POSTFLUSH = 0x20,
474 QUEUE_ORDERED_FUA = 0x40,
475
476 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
477 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
478 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
479 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
480 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
481 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
482 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
483 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
484
485 /*
486 * Ordered operation sequence
487 */
488 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
489 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
490 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
491 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
492 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
493 QUEUE_ORDSEQ_DONE = 0x20,
494};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495
496#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
497#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
498#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
Tejun Heo797e7db2006-01-06 09:51:03 +0100499#define blk_queue_flushing(q) ((q)->ordseq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500
501#define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
502#define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
503#define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
504#define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
505
506#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
507
508#define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
509#define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
510#define blk_pm_request(rq) \
511 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
512
Tejun Heo8922e162005-10-20 16:23:44 +0200513#define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514#define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
Tejun Heo797e7db2006-01-06 09:51:03 +0100515#define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
518
519#define rq_data_dir(rq) ((rq)->flags & 1)
520
521static inline int blk_queue_full(struct request_queue *q, int rw)
522{
523 if (rw == READ)
524 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
525 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
526}
527
528static inline void blk_set_queue_full(struct request_queue *q, int rw)
529{
530 if (rw == READ)
531 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
532 else
533 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
534}
535
536static inline void blk_clear_queue_full(struct request_queue *q, int rw)
537{
538 if (rw == READ)
539 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
540 else
541 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
542}
543
544
545/*
546 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
547 * it already be started by driver.
548 */
549#define RQ_NOMERGE_FLAGS \
550 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
551#define rq_mergeable(rq) \
552 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
553
554/*
555 * noop, requests are automagically marked as active/inactive by I/O
556 * scheduler -- see elv_next_request
557 */
558#define blk_queue_headactive(q, head_active)
559
560/*
561 * q->prep_rq_fn return values
562 */
563#define BLKPREP_OK 0 /* serve it */
564#define BLKPREP_KILL 1 /* fatal error, kill */
565#define BLKPREP_DEFER 2 /* leave on queue */
566
567extern unsigned long blk_max_low_pfn, blk_max_pfn;
568
569/*
570 * standard bounce addresses:
571 *
572 * BLK_BOUNCE_HIGH : bounce all highmem pages
573 * BLK_BOUNCE_ANY : don't bounce anything
574 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
575 */
576#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
577#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
578#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
579
580#ifdef CONFIG_MMU
581extern int init_emergency_isa_pool(void);
582extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
583#else
584static inline int init_emergency_isa_pool(void)
585{
586 return 0;
587}
588static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
589{
590}
591#endif /* CONFIG_MMU */
592
593#define rq_for_each_bio(_bio, rq) \
594 if ((rq->bio)) \
595 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
596
597struct sec_size {
598 unsigned block_size;
599 unsigned block_size_bits;
600};
601
602extern int blk_register_queue(struct gendisk *disk);
603extern void blk_unregister_queue(struct gendisk *disk);
604extern void register_disk(struct gendisk *dev);
605extern void generic_make_request(struct bio *bio);
606extern void blk_put_request(struct request *);
Mike Christie6e39b692005-11-11 05:30:24 -0600607extern void __blk_put_request(request_queue_t *, struct request *);
Tejun Heo8ffdc652006-01-06 09:49:03 +0100608extern void blk_end_sync_rq(struct request *rq, int error);
Al Viro8267e262005-10-21 03:20:53 -0400609extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
Tejun Heo 867d1192005-04-24 02:06:05 -0500610extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611extern void blk_requeue_request(request_queue_t *, struct request *);
612extern void blk_plug_device(request_queue_t *);
613extern int blk_remove_plug(request_queue_t *);
614extern void blk_recount_segments(request_queue_t *, struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
Christoph Hellwig21b2f0c2006-03-22 17:52:04 +0100616extern int sg_scsi_ioctl(struct file *, struct request_queue *,
617 struct gendisk *, struct scsi_ioctl_command __user *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618extern void blk_start_queue(request_queue_t *q);
619extern void blk_stop_queue(request_queue_t *q);
620extern void blk_sync_queue(struct request_queue *q);
621extern void __blk_stop_queue(request_queue_t *q);
622extern void blk_run_queue(request_queue_t *);
623extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
Jens Axboedd1cab92005-06-20 14:06:01 +0200624extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
625extern int blk_rq_unmap_user(struct bio *, unsigned int);
Al Viro8267e262005-10-21 03:20:53 -0400626extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t);
James Bottomley f1970ba2005-06-20 14:06:52 +0200627extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
James Bottomley 994ca9a2005-06-20 14:11:09 +0200628extern int blk_execute_rq(request_queue_t *, struct gendisk *,
629 struct request *, int);
Mike Christie6e39b692005-11-11 05:30:24 -0600630extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *,
Jens Axboe15fc8582006-01-06 10:00:50 +0100631 struct request *, int, rq_end_io_fn *);
Mike Christie6e39b692005-11-11 05:30:24 -0600632
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
634{
635 return bdev->bd_disk->queue;
636}
637
638static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
639 struct page *page)
640{
641 if (bdi && bdi->unplug_io_fn)
642 bdi->unplug_io_fn(bdi, page);
643}
644
645static inline void blk_run_address_space(struct address_space *mapping)
646{
647 if (mapping)
648 blk_run_backing_dev(mapping->backing_dev_info, NULL);
649}
650
651/*
652 * end_request() and friends. Must be called with the request queue spinlock
653 * acquired. All functions called within end_request() _must_be_ atomic.
654 *
655 * Several drivers define their own end_request and call
656 * end_that_request_first() and end_that_request_last()
657 * for parts of the original function. This prevents
658 * code duplication in drivers.
659 */
660extern int end_that_request_first(struct request *, int, int);
661extern int end_that_request_chunk(struct request *, int, int);
Tejun Heo8ffdc652006-01-06 09:49:03 +0100662extern void end_that_request_last(struct request *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663extern void end_request(struct request *req, int uptodate);
Jens Axboeff856ba2006-01-09 16:02:34 +0100664extern void blk_complete_request(struct request *);
665
666static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
667{
668 if (blk_fs_request(rq))
669 return (nr_bytes >= (rq->hard_nr_sectors << 9));
670 else if (blk_pc_request(rq))
671 return nr_bytes >= rq->data_len;
672
673 return 0;
674}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
676/*
677 * end_that_request_first/chunk() takes an uptodate argument. we account
678 * any value <= as an io error. 0 means -EIO for compatability reasons,
679 * any other < 0 value is the direct error type. An uptodate value of
680 * 1 indicates successful io completion
681 */
682#define end_io_error(uptodate) (unlikely((uptodate) <= 0))
683
684static inline void blkdev_dequeue_request(struct request *req)
685{
Tejun Heo8922e162005-10-20 16:23:44 +0200686 elv_dequeue_request(req->q, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689/*
Jens Axboe1b47f532005-10-20 16:37:00 +0200690 * This should be in elevator.h, but that requires pulling in rq and q
691 */
692static inline void elv_dispatch_add_tail(struct request_queue *q,
693 struct request *rq)
694{
Tejun Heo06b86242005-10-20 16:46:23 +0200695 if (q->last_merge == rq)
696 q->last_merge = NULL;
Tejun Heo15853af2005-11-10 08:52:05 +0100697 q->nr_sorted--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698
Jens Axboe1b47f532005-10-20 16:37:00 +0200699 q->end_sector = rq_end_sector(rq);
700 q->boundary_rq = rq;
701 list_add_tail(&rq->queuelist, &q->queue_head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702}
703
704/*
705 * Access functions for manipulating queue properties
706 */
Christoph Lameter19460892005-06-23 00:08:19 -0700707extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
708 spinlock_t *lock, int node_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
710extern void blk_cleanup_queue(request_queue_t *);
711extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
712extern void blk_queue_bounce_limit(request_queue_t *, u64);
Jens Axboe2cb2e142006-01-17 09:04:32 +0100713extern void blk_queue_max_sectors(request_queue_t *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
715extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
716extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
717extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
718extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
719extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
720extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
721extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
722extern void blk_queue_dma_alignment(request_queue_t *, int);
Jens Axboeff856ba2006-01-09 16:02:34 +0100723extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
Tejun Heo797e7db2006-01-06 09:51:03 +0100725extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
Tejun Heo797e7db2006-01-06 09:51:03 +0100727extern int blk_do_ordered(request_queue_t *, struct request **);
728extern unsigned blk_ordered_cur_seq(request_queue_t *);
729extern unsigned blk_ordered_req_seq(struct request *);
730extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
732extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
733extern void blk_dump_rq_flags(struct request *, char *);
734extern void generic_unplug_device(request_queue_t *);
735extern void __generic_unplug_device(request_queue_t *);
736extern long nr_blockdev_pages(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737
738int blk_get_queue(request_queue_t *);
Al Viro8267e262005-10-21 03:20:53 -0400739request_queue_t *blk_alloc_queue(gfp_t);
740request_queue_t *blk_alloc_queue_node(gfp_t, int);
Al Viro483f4af2006-03-18 18:34:37 -0500741extern void blk_put_queue(request_queue_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
743/*
744 * tag stuff
745 */
746#define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
747#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
748#define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
749extern int blk_queue_start_tag(request_queue_t *, struct request *);
750extern struct request *blk_queue_find_tag(request_queue_t *, int);
751extern void blk_queue_end_tag(request_queue_t *, struct request *);
752extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
753extern void blk_queue_free_tags(request_queue_t *);
754extern int blk_queue_resize_tags(request_queue_t *, int);
755extern void blk_queue_invalidate_tags(request_queue_t *);
756extern long blk_congestion_wait(int rw, long timeout);
757
758extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
759extern int blkdev_issue_flush(struct block_device *, sector_t *);
760
761#define MAX_PHYS_SEGMENTS 128
762#define MAX_HW_SEGMENTS 128
Mike Christiedefd94b2005-12-05 02:37:06 -0600763#define SAFE_MAX_SECTORS 255
764#define BLK_DEF_MAX_SECTORS 1024
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765
766#define MAX_SEGMENT_SIZE 65536
767
768#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
769
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770static inline int queue_hardsect_size(request_queue_t *q)
771{
772 int retval = 512;
773
774 if (q && q->hardsect_size)
775 retval = q->hardsect_size;
776
777 return retval;
778}
779
780static inline int bdev_hardsect_size(struct block_device *bdev)
781{
782 return queue_hardsect_size(bdev_get_queue(bdev));
783}
784
785static inline int queue_dma_alignment(request_queue_t *q)
786{
787 int retval = 511;
788
789 if (q && q->dma_alignment)
790 retval = q->dma_alignment;
791
792 return retval;
793}
794
795static inline int bdev_dma_aligment(struct block_device *bdev)
796{
797 return queue_dma_alignment(bdev_get_queue(bdev));
798}
799
800#define blk_finished_io(nsects) do { } while (0)
801#define blk_started_io(nsects) do { } while (0)
802
803/* assumes size > 256 */
804static inline unsigned int blksize_bits(unsigned int size)
805{
806 unsigned int bits = 8;
807 do {
808 bits++;
809 size >>= 1;
810 } while (size > 256);
811 return bits;
812}
813
Adrian Bunk2befb9e2005-09-10 00:27:17 -0700814static inline unsigned int block_size(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815{
816 return bdev->bd_block_size;
817}
818
819typedef struct {struct page *v;} Sector;
820
821unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
822
823static inline void put_dev_sector(Sector p)
824{
825 page_cache_release(p.v);
826}
827
828struct work_struct;
829int kblockd_schedule_work(struct work_struct *work);
830void kblockd_flush(void);
831
832#ifdef CONFIG_LBD
833# include <asm/div64.h>
834# define sector_div(a, b) do_div(a, b)
835#else
836# define sector_div(n, b)( \
837{ \
838 int _res; \
839 _res = (n) % (b); \
840 (n) /= (b); \
841 _res; \
842} \
843)
844#endif
845
846#define MODULE_ALIAS_BLOCKDEV(major,minor) \
847 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
848#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
849 MODULE_ALIAS("block-major-" __stringify(major) "-*")
850
851
852#endif