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1da177e4 LT |
1 | #ifndef _LINUX_BLKDEV_H |
2 | #define _LINUX_BLKDEV_H | |
3 | ||
bcfd8d36 | 4 | #include <linux/sched.h> |
1da177e4 LT |
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 | ||
9361401e DH |
20 | #ifdef CONFIG_LBD |
21 | # include <asm/div64.h> | |
22 | # define sector_div(a, b) do_div(a, b) | |
23 | #else | |
24 | # define sector_div(n, b)( \ | |
25 | { \ | |
26 | int _res; \ | |
27 | _res = (n) % (b); \ | |
28 | (n) /= (b); \ | |
29 | _res; \ | |
30 | } \ | |
31 | ) | |
32 | #endif | |
33 | ||
34 | #ifdef CONFIG_BLOCK | |
35 | ||
21b2f0c8 CH |
36 | struct scsi_ioctl_command; |
37 | ||
1da177e4 LT |
38 | struct request_queue; |
39 | typedef struct request_queue request_queue_t; | |
40 | struct elevator_queue; | |
41 | typedef struct elevator_queue elevator_t; | |
42 | struct request_pm_state; | |
2056a782 | 43 | struct blk_trace; |
1da177e4 LT |
44 | |
45 | #define BLKDEV_MIN_RQ 4 | |
46 | #define BLKDEV_MAX_RQ 128 /* Default maximum */ | |
47 | ||
48 | /* | |
49 | * This is the per-process anticipatory I/O scheduler state. | |
50 | */ | |
51 | struct as_io_context { | |
52 | spinlock_t lock; | |
53 | ||
54 | void (*dtor)(struct as_io_context *aic); /* destructor */ | |
55 | void (*exit)(struct as_io_context *aic); /* called on task exit */ | |
56 | ||
57 | unsigned long state; | |
58 | atomic_t nr_queued; /* queued reads & sync writes */ | |
59 | atomic_t nr_dispatched; /* number of requests gone to the drivers */ | |
60 | ||
61 | /* IO History tracking */ | |
62 | /* Thinktime */ | |
63 | unsigned long last_end_request; | |
64 | unsigned long ttime_total; | |
65 | unsigned long ttime_samples; | |
66 | unsigned long ttime_mean; | |
67 | /* Layout pattern */ | |
68 | unsigned int seek_samples; | |
69 | sector_t last_request_pos; | |
70 | u64 seek_total; | |
71 | sector_t seek_mean; | |
72 | }; | |
73 | ||
74 | struct cfq_queue; | |
75 | struct cfq_io_context { | |
e2d74ac0 | 76 | struct rb_node rb_node; |
22e2c507 JA |
77 | void *key; |
78 | ||
e2d74ac0 JA |
79 | struct cfq_queue *cfqq[2]; |
80 | ||
22e2c507 JA |
81 | struct io_context *ioc; |
82 | ||
83 | unsigned long last_end_request; | |
206dc69b JA |
84 | sector_t last_request_pos; |
85 | unsigned long last_queue; | |
86 | ||
22e2c507 JA |
87 | unsigned long ttime_total; |
88 | unsigned long ttime_samples; | |
89 | unsigned long ttime_mean; | |
90 | ||
206dc69b JA |
91 | unsigned int seek_samples; |
92 | u64 seek_total; | |
93 | sector_t seek_mean; | |
94 | ||
d9ff4187 AV |
95 | struct list_head queue_list; |
96 | ||
e2d74ac0 JA |
97 | void (*dtor)(struct io_context *); /* destructor */ |
98 | void (*exit)(struct io_context *); /* called on task exit */ | |
1da177e4 LT |
99 | }; |
100 | ||
101 | /* | |
102 | * This is the per-process I/O subsystem state. It is refcounted and | |
103 | * kmalloc'ed. Currently all fields are modified in process io context | |
104 | * (apart from the atomic refcount), so require no locking. | |
105 | */ | |
106 | struct io_context { | |
107 | atomic_t refcount; | |
22e2c507 JA |
108 | struct task_struct *task; |
109 | ||
fc46379d | 110 | unsigned int ioprio_changed; |
1da177e4 LT |
111 | |
112 | /* | |
113 | * For request batching | |
114 | */ | |
115 | unsigned long last_waited; /* Time last woken after wait for request */ | |
116 | int nr_batch_requests; /* Number of requests left in the batch */ | |
117 | ||
1da177e4 | 118 | struct as_io_context *aic; |
e2d74ac0 | 119 | struct rb_root cic_root; |
1da177e4 LT |
120 | }; |
121 | ||
122 | void put_io_context(struct io_context *ioc); | |
123 | void exit_io_context(void); | |
b5deef90 | 124 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
1da177e4 LT |
125 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); |
126 | void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); | |
127 | ||
128 | struct request; | |
8ffdc655 | 129 | typedef void (rq_end_io_fn)(struct request *, int); |
1da177e4 LT |
130 | |
131 | struct request_list { | |
132 | int count[2]; | |
133 | int starved[2]; | |
cb98fc8b | 134 | int elvpriv; |
1da177e4 LT |
135 | mempool_t *rq_pool; |
136 | wait_queue_head_t wait[2]; | |
1da177e4 LT |
137 | }; |
138 | ||
4aff5e23 JA |
139 | /* |
140 | * request command types | |
141 | */ | |
142 | enum rq_cmd_type_bits { | |
143 | REQ_TYPE_FS = 1, /* fs request */ | |
144 | REQ_TYPE_BLOCK_PC, /* scsi command */ | |
145 | REQ_TYPE_SENSE, /* sense request */ | |
146 | REQ_TYPE_PM_SUSPEND, /* suspend request */ | |
147 | REQ_TYPE_PM_RESUME, /* resume request */ | |
148 | REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ | |
149 | REQ_TYPE_FLUSH, /* flush request */ | |
150 | REQ_TYPE_SPECIAL, /* driver defined type */ | |
151 | REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ | |
152 | /* | |
153 | * for ATA/ATAPI devices. this really doesn't belong here, ide should | |
154 | * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver | |
155 | * private REQ_LB opcodes to differentiate what type of request this is | |
156 | */ | |
157 | REQ_TYPE_ATA_CMD, | |
158 | REQ_TYPE_ATA_TASK, | |
159 | REQ_TYPE_ATA_TASKFILE, | |
160 | }; | |
161 | ||
162 | /* | |
163 | * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being | |
164 | * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a | |
165 | * SCSI cdb. | |
166 | * | |
167 | * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, | |
168 | * typically to differentiate REQ_TYPE_SPECIAL requests. | |
169 | * | |
170 | */ | |
171 | enum { | |
172 | /* | |
173 | * just examples for now | |
174 | */ | |
175 | REQ_LB_OP_EJECT = 0x40, /* eject request */ | |
176 | REQ_LB_OP_FLUSH = 0x41, /* flush device */ | |
177 | }; | |
178 | ||
179 | /* | |
180 | * request type modified bits. first three bits match BIO_RW* bits, important | |
181 | */ | |
182 | enum rq_flag_bits { | |
183 | __REQ_RW, /* not set, read. set, write */ | |
184 | __REQ_FAILFAST, /* no low level driver retries */ | |
185 | __REQ_SORTED, /* elevator knows about this request */ | |
186 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ | |
187 | __REQ_HARDBARRIER, /* may not be passed by drive either */ | |
188 | __REQ_FUA, /* forced unit access */ | |
189 | __REQ_NOMERGE, /* don't touch this for merging */ | |
190 | __REQ_STARTED, /* drive already may have started this one */ | |
191 | __REQ_DONTPREP, /* don't call prep for this one */ | |
192 | __REQ_QUEUED, /* uses queueing */ | |
193 | __REQ_ELVPRIV, /* elevator private data attached */ | |
194 | __REQ_FAILED, /* set if the request failed */ | |
195 | __REQ_QUIET, /* don't worry about errors */ | |
196 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
197 | __REQ_ORDERED_COLOR, /* is before or after barrier */ | |
198 | __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ | |
49171e5c | 199 | __REQ_ALLOCED, /* request came from our alloc pool */ |
5404bc7a | 200 | __REQ_RW_META, /* metadata io request */ |
4aff5e23 JA |
201 | __REQ_NR_BITS, /* stops here */ |
202 | }; | |
203 | ||
204 | #define REQ_RW (1 << __REQ_RW) | |
205 | #define REQ_FAILFAST (1 << __REQ_FAILFAST) | |
206 | #define REQ_SORTED (1 << __REQ_SORTED) | |
207 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) | |
208 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) | |
209 | #define REQ_FUA (1 << __REQ_FUA) | |
210 | #define REQ_NOMERGE (1 << __REQ_NOMERGE) | |
211 | #define REQ_STARTED (1 << __REQ_STARTED) | |
212 | #define REQ_DONTPREP (1 << __REQ_DONTPREP) | |
213 | #define REQ_QUEUED (1 << __REQ_QUEUED) | |
214 | #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) | |
215 | #define REQ_FAILED (1 << __REQ_FAILED) | |
216 | #define REQ_QUIET (1 << __REQ_QUIET) | |
217 | #define REQ_PREEMPT (1 << __REQ_PREEMPT) | |
218 | #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) | |
219 | #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) | |
49171e5c | 220 | #define REQ_ALLOCED (1 << __REQ_ALLOCED) |
5404bc7a | 221 | #define REQ_RW_META (1 << __REQ_RW_META) |
4aff5e23 | 222 | |
1da177e4 LT |
223 | #define BLK_MAX_CDB 16 |
224 | ||
225 | /* | |
226 | * try to put the fields that are referenced together in the same cacheline | |
227 | */ | |
228 | struct request { | |
ff856bad JA |
229 | struct list_head queuelist; |
230 | struct list_head donelist; | |
231 | ||
e6a1c874 JA |
232 | request_queue_t *q; |
233 | ||
4aff5e23 JA |
234 | unsigned int cmd_flags; |
235 | enum rq_cmd_type_bits cmd_type; | |
1da177e4 LT |
236 | |
237 | /* Maintain bio traversal state for part by part I/O submission. | |
238 | * hard_* are block layer internals, no driver should touch them! | |
239 | */ | |
240 | ||
241 | sector_t sector; /* next sector to submit */ | |
e6a1c874 | 242 | sector_t hard_sector; /* next sector to complete */ |
1da177e4 | 243 | unsigned long nr_sectors; /* no. of sectors left to submit */ |
e6a1c874 | 244 | unsigned long hard_nr_sectors; /* no. of sectors left to complete */ |
1da177e4 LT |
245 | /* no. of sectors left to submit in the current segment */ |
246 | unsigned int current_nr_sectors; | |
247 | ||
1da177e4 LT |
248 | /* no. of sectors left to complete in the current segment */ |
249 | unsigned int hard_cur_sectors; | |
250 | ||
251 | struct bio *bio; | |
252 | struct bio *biotail; | |
253 | ||
9817064b | 254 | struct hlist_node hash; /* merge hash */ |
e6a1c874 JA |
255 | /* |
256 | * The rb_node is only used inside the io scheduler, requests | |
257 | * are pruned when moved to the dispatch queue. So let the | |
258 | * completion_data share space with the rb_node. | |
259 | */ | |
260 | union { | |
261 | struct rb_node rb_node; /* sort/lookup */ | |
262 | void *completion_data; | |
263 | }; | |
9817064b | 264 | |
ff7d145f JA |
265 | /* |
266 | * two pointers are available for the IO schedulers, if they need | |
267 | * more they have to dynamically allocate it. | |
268 | */ | |
1da177e4 | 269 | void *elevator_private; |
ff7d145f JA |
270 | void *elevator_private2; |
271 | ||
8f34ee75 | 272 | struct gendisk *rq_disk; |
1da177e4 LT |
273 | unsigned long start_time; |
274 | ||
275 | /* Number of scatter-gather DMA addr+len pairs after | |
276 | * physical address coalescing is performed. | |
277 | */ | |
278 | unsigned short nr_phys_segments; | |
279 | ||
280 | /* Number of scatter-gather addr+len pairs after | |
281 | * physical and DMA remapping hardware coalescing is performed. | |
282 | * This is the number of scatter-gather entries the driver | |
283 | * will actually have to deal with after DMA mapping is done. | |
284 | */ | |
285 | unsigned short nr_hw_segments; | |
286 | ||
8f34ee75 JA |
287 | unsigned short ioprio; |
288 | ||
1da177e4 | 289 | void *special; |
8f34ee75 | 290 | char *buffer; |
1da177e4 | 291 | |
cdd60262 JA |
292 | int tag; |
293 | int errors; | |
294 | ||
295 | int ref_count; | |
296 | ||
1da177e4 LT |
297 | /* |
298 | * when request is used as a packet command carrier | |
299 | */ | |
300 | unsigned int cmd_len; | |
301 | unsigned char cmd[BLK_MAX_CDB]; | |
302 | ||
303 | unsigned int data_len; | |
1da177e4 | 304 | unsigned int sense_len; |
8f34ee75 | 305 | void *data; |
1da177e4 LT |
306 | void *sense; |
307 | ||
308 | unsigned int timeout; | |
17e01f21 | 309 | int retries; |
1da177e4 | 310 | |
1da177e4 | 311 | /* |
c00895ab | 312 | * completion callback. |
1da177e4 LT |
313 | */ |
314 | rq_end_io_fn *end_io; | |
315 | void *end_io_data; | |
316 | }; | |
317 | ||
318 | /* | |
4aff5e23 | 319 | * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME |
1da177e4 LT |
320 | * requests. Some step values could eventually be made generic. |
321 | */ | |
322 | struct request_pm_state | |
323 | { | |
324 | /* PM state machine step value, currently driver specific */ | |
325 | int pm_step; | |
326 | /* requested PM state value (S1, S2, S3, S4, ...) */ | |
327 | u32 pm_state; | |
328 | void* data; /* for driver use */ | |
329 | }; | |
330 | ||
331 | #include <linux/elevator.h> | |
332 | ||
333 | typedef int (merge_request_fn) (request_queue_t *, struct request *, | |
334 | struct bio *); | |
335 | typedef int (merge_requests_fn) (request_queue_t *, struct request *, | |
336 | struct request *); | |
337 | typedef void (request_fn_proc) (request_queue_t *q); | |
338 | typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); | |
339 | typedef int (prep_rq_fn) (request_queue_t *, struct request *); | |
340 | typedef void (unplug_fn) (request_queue_t *); | |
341 | ||
342 | struct bio_vec; | |
343 | typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); | |
344 | typedef void (activity_fn) (void *data, int rw); | |
345 | typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); | |
797e7dbb | 346 | typedef void (prepare_flush_fn) (request_queue_t *, struct request *); |
ff856bad | 347 | typedef void (softirq_done_fn)(struct request *); |
1da177e4 LT |
348 | |
349 | enum blk_queue_state { | |
350 | Queue_down, | |
351 | Queue_up, | |
352 | }; | |
353 | ||
1da177e4 LT |
354 | struct blk_queue_tag { |
355 | struct request **tag_index; /* map of busy tags */ | |
356 | unsigned long *tag_map; /* bit map of free/busy tags */ | |
357 | struct list_head busy_list; /* fifo list of busy tags */ | |
358 | int busy; /* current depth */ | |
359 | int max_depth; /* what we will send to device */ | |
ba025082 | 360 | int real_max_depth; /* what the array can hold */ |
1da177e4 LT |
361 | atomic_t refcnt; /* map can be shared */ |
362 | }; | |
363 | ||
364 | struct request_queue | |
365 | { | |
366 | /* | |
367 | * Together with queue_head for cacheline sharing | |
368 | */ | |
369 | struct list_head queue_head; | |
370 | struct request *last_merge; | |
371 | elevator_t *elevator; | |
372 | ||
373 | /* | |
374 | * the queue request freelist, one for reads and one for writes | |
375 | */ | |
376 | struct request_list rq; | |
377 | ||
378 | request_fn_proc *request_fn; | |
379 | merge_request_fn *back_merge_fn; | |
380 | merge_request_fn *front_merge_fn; | |
381 | merge_requests_fn *merge_requests_fn; | |
382 | make_request_fn *make_request_fn; | |
383 | prep_rq_fn *prep_rq_fn; | |
384 | unplug_fn *unplug_fn; | |
385 | merge_bvec_fn *merge_bvec_fn; | |
386 | activity_fn *activity_fn; | |
387 | issue_flush_fn *issue_flush_fn; | |
388 | prepare_flush_fn *prepare_flush_fn; | |
ff856bad | 389 | softirq_done_fn *softirq_done_fn; |
1da177e4 | 390 | |
8922e16c TH |
391 | /* |
392 | * Dispatch queue sorting | |
393 | */ | |
1b47f531 | 394 | sector_t end_sector; |
8922e16c | 395 | struct request *boundary_rq; |
8922e16c | 396 | |
1da177e4 LT |
397 | /* |
398 | * Auto-unplugging state | |
399 | */ | |
400 | struct timer_list unplug_timer; | |
401 | int unplug_thresh; /* After this many requests */ | |
402 | unsigned long unplug_delay; /* After this many jiffies */ | |
403 | struct work_struct unplug_work; | |
404 | ||
405 | struct backing_dev_info backing_dev_info; | |
406 | ||
407 | /* | |
408 | * The queue owner gets to use this for whatever they like. | |
409 | * ll_rw_blk doesn't touch it. | |
410 | */ | |
411 | void *queuedata; | |
412 | ||
413 | void *activity_data; | |
414 | ||
415 | /* | |
416 | * queue needs bounce pages for pages above this limit | |
417 | */ | |
418 | unsigned long bounce_pfn; | |
8267e268 | 419 | gfp_t bounce_gfp; |
1da177e4 LT |
420 | |
421 | /* | |
422 | * various queue flags, see QUEUE_* below | |
423 | */ | |
424 | unsigned long queue_flags; | |
425 | ||
426 | /* | |
152587de | 427 | * protects queue structures from reentrancy. ->__queue_lock should |
428 | * _never_ be used directly, it is queue private. always use | |
429 | * ->queue_lock. | |
1da177e4 | 430 | */ |
152587de | 431 | spinlock_t __queue_lock; |
1da177e4 LT |
432 | spinlock_t *queue_lock; |
433 | ||
434 | /* | |
435 | * queue kobject | |
436 | */ | |
437 | struct kobject kobj; | |
438 | ||
439 | /* | |
440 | * queue settings | |
441 | */ | |
442 | unsigned long nr_requests; /* Max # of requests */ | |
443 | unsigned int nr_congestion_on; | |
444 | unsigned int nr_congestion_off; | |
445 | unsigned int nr_batching; | |
446 | ||
2cb2e147 JA |
447 | unsigned int max_sectors; |
448 | unsigned int max_hw_sectors; | |
1da177e4 LT |
449 | unsigned short max_phys_segments; |
450 | unsigned short max_hw_segments; | |
451 | unsigned short hardsect_size; | |
452 | unsigned int max_segment_size; | |
453 | ||
454 | unsigned long seg_boundary_mask; | |
455 | unsigned int dma_alignment; | |
456 | ||
457 | struct blk_queue_tag *queue_tags; | |
458 | ||
15853af9 | 459 | unsigned int nr_sorted; |
1da177e4 LT |
460 | unsigned int in_flight; |
461 | ||
462 | /* | |
463 | * sg stuff | |
464 | */ | |
465 | unsigned int sg_timeout; | |
466 | unsigned int sg_reserved_size; | |
1946089a | 467 | int node; |
6c5c9341 | 468 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
2056a782 | 469 | struct blk_trace *blk_trace; |
6c5c9341 | 470 | #endif |
1da177e4 LT |
471 | /* |
472 | * reserved for flush operations | |
473 | */ | |
797e7dbb TH |
474 | unsigned int ordered, next_ordered, ordseq; |
475 | int orderr, ordcolor; | |
476 | struct request pre_flush_rq, bar_rq, post_flush_rq; | |
477 | struct request *orig_bar_rq; | |
478 | unsigned int bi_size; | |
483f4afc AV |
479 | |
480 | struct mutex sysfs_lock; | |
1da177e4 LT |
481 | }; |
482 | ||
1da177e4 LT |
483 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ |
484 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ | |
485 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ | |
486 | #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ | |
487 | #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ | |
488 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ | |
489 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ | |
490 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ | |
64521d1a | 491 | #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ |
797e7dbb TH |
492 | |
493 | enum { | |
494 | /* | |
495 | * Hardbarrier is supported with one of the following methods. | |
496 | * | |
497 | * NONE : hardbarrier unsupported | |
498 | * DRAIN : ordering by draining is enough | |
499 | * DRAIN_FLUSH : ordering by draining w/ pre and post flushes | |
500 | * DRAIN_FUA : ordering by draining w/ pre flush and FUA write | |
501 | * TAG : ordering by tag is enough | |
502 | * TAG_FLUSH : ordering by tag w/ pre and post flushes | |
503 | * TAG_FUA : ordering by tag w/ pre flush and FUA write | |
504 | */ | |
505 | QUEUE_ORDERED_NONE = 0x00, | |
506 | QUEUE_ORDERED_DRAIN = 0x01, | |
507 | QUEUE_ORDERED_TAG = 0x02, | |
508 | ||
509 | QUEUE_ORDERED_PREFLUSH = 0x10, | |
510 | QUEUE_ORDERED_POSTFLUSH = 0x20, | |
511 | QUEUE_ORDERED_FUA = 0x40, | |
512 | ||
513 | QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | | |
514 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
515 | QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | | |
516 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
517 | QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | | |
518 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
519 | QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | | |
520 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
521 | ||
522 | /* | |
523 | * Ordered operation sequence | |
524 | */ | |
525 | QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ | |
526 | QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ | |
527 | QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ | |
528 | QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ | |
529 | QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ | |
530 | QUEUE_ORDSEQ_DONE = 0x20, | |
531 | }; | |
1da177e4 LT |
532 | |
533 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) | |
534 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) | |
535 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) | |
797e7dbb | 536 | #define blk_queue_flushing(q) ((q)->ordseq) |
1da177e4 | 537 | |
4aff5e23 JA |
538 | #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) |
539 | #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) | |
540 | #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) | |
541 | #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) | |
542 | ||
543 | #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) | |
544 | #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) | |
1da177e4 LT |
545 | |
546 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) | |
547 | ||
4aff5e23 JA |
548 | #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) |
549 | #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) | |
1da177e4 | 550 | #define blk_pm_request(rq) \ |
4aff5e23 | 551 | (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) |
1da177e4 | 552 | |
4aff5e23 JA |
553 | #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) |
554 | #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) | |
555 | #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) | |
1da177e4 LT |
556 | |
557 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) | |
558 | ||
4aff5e23 | 559 | #define rq_data_dir(rq) ((rq)->cmd_flags & 1) |
1da177e4 | 560 | |
9e2585a8 JA |
561 | /* |
562 | * We regard a request as sync, if it's a READ or a SYNC write. | |
563 | */ | |
564 | #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) | |
5404bc7a | 565 | #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) |
9e2585a8 | 566 | |
1da177e4 LT |
567 | static inline int blk_queue_full(struct request_queue *q, int rw) |
568 | { | |
569 | if (rw == READ) | |
570 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
571 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
572 | } | |
573 | ||
574 | static inline void blk_set_queue_full(struct request_queue *q, int rw) | |
575 | { | |
576 | if (rw == READ) | |
577 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
578 | else | |
579 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
580 | } | |
581 | ||
582 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) | |
583 | { | |
584 | if (rw == READ) | |
585 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
586 | else | |
587 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
588 | } | |
589 | ||
590 | ||
591 | /* | |
592 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may | |
593 | * it already be started by driver. | |
594 | */ | |
595 | #define RQ_NOMERGE_FLAGS \ | |
596 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) | |
597 | #define rq_mergeable(rq) \ | |
4aff5e23 | 598 | (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) |
1da177e4 | 599 | |
1da177e4 LT |
600 | /* |
601 | * q->prep_rq_fn return values | |
602 | */ | |
603 | #define BLKPREP_OK 0 /* serve it */ | |
604 | #define BLKPREP_KILL 1 /* fatal error, kill */ | |
605 | #define BLKPREP_DEFER 2 /* leave on queue */ | |
606 | ||
607 | extern unsigned long blk_max_low_pfn, blk_max_pfn; | |
608 | ||
609 | /* | |
610 | * standard bounce addresses: | |
611 | * | |
612 | * BLK_BOUNCE_HIGH : bounce all highmem pages | |
613 | * BLK_BOUNCE_ANY : don't bounce anything | |
614 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary | |
615 | */ | |
616 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) | |
617 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) | |
618 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) | |
619 | ||
620 | #ifdef CONFIG_MMU | |
621 | extern int init_emergency_isa_pool(void); | |
622 | extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); | |
623 | #else | |
624 | static inline int init_emergency_isa_pool(void) | |
625 | { | |
626 | return 0; | |
627 | } | |
628 | static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) | |
629 | { | |
630 | } | |
631 | #endif /* CONFIG_MMU */ | |
632 | ||
633 | #define rq_for_each_bio(_bio, rq) \ | |
634 | if ((rq->bio)) \ | |
635 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) | |
636 | ||
1da177e4 LT |
637 | extern int blk_register_queue(struct gendisk *disk); |
638 | extern void blk_unregister_queue(struct gendisk *disk); | |
639 | extern void register_disk(struct gendisk *dev); | |
640 | extern void generic_make_request(struct bio *bio); | |
641 | extern void blk_put_request(struct request *); | |
6e39b69e | 642 | extern void __blk_put_request(request_queue_t *, struct request *); |
8ffdc655 | 643 | extern void blk_end_sync_rq(struct request *rq, int error); |
8267e268 | 644 | extern struct request *blk_get_request(request_queue_t *, int, gfp_t); |
867d1191 | 645 | extern void blk_insert_request(request_queue_t *, struct request *, int, void *); |
1da177e4 LT |
646 | extern void blk_requeue_request(request_queue_t *, struct request *); |
647 | extern void blk_plug_device(request_queue_t *); | |
648 | extern int blk_remove_plug(request_queue_t *); | |
649 | extern void blk_recount_segments(request_queue_t *, struct bio *); | |
1da177e4 | 650 | extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); |
21b2f0c8 CH |
651 | extern int sg_scsi_ioctl(struct file *, struct request_queue *, |
652 | struct gendisk *, struct scsi_ioctl_command __user *); | |
1da177e4 LT |
653 | extern void blk_start_queue(request_queue_t *q); |
654 | extern void blk_stop_queue(request_queue_t *q); | |
655 | extern void blk_sync_queue(struct request_queue *q); | |
656 | extern void __blk_stop_queue(request_queue_t *q); | |
657 | extern void blk_run_queue(request_queue_t *); | |
dc72ef4a | 658 | extern void blk_start_queueing(request_queue_t *); |
1da177e4 | 659 | extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); |
dd1cab95 JA |
660 | extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int); |
661 | extern int blk_rq_unmap_user(struct bio *, unsigned int); | |
8267e268 | 662 | extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); |
f1970baf | 663 | extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int); |
994ca9a1 JB |
664 | extern int blk_execute_rq(request_queue_t *, struct gendisk *, |
665 | struct request *, int); | |
6e39b69e | 666 | extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, |
15fc858a | 667 | struct request *, int, rq_end_io_fn *); |
6e39b69e | 668 | |
1da177e4 LT |
669 | static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |
670 | { | |
671 | return bdev->bd_disk->queue; | |
672 | } | |
673 | ||
674 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, | |
675 | struct page *page) | |
676 | { | |
677 | if (bdi && bdi->unplug_io_fn) | |
678 | bdi->unplug_io_fn(bdi, page); | |
679 | } | |
680 | ||
681 | static inline void blk_run_address_space(struct address_space *mapping) | |
682 | { | |
683 | if (mapping) | |
684 | blk_run_backing_dev(mapping->backing_dev_info, NULL); | |
685 | } | |
686 | ||
687 | /* | |
688 | * end_request() and friends. Must be called with the request queue spinlock | |
689 | * acquired. All functions called within end_request() _must_be_ atomic. | |
690 | * | |
691 | * Several drivers define their own end_request and call | |
692 | * end_that_request_first() and end_that_request_last() | |
693 | * for parts of the original function. This prevents | |
694 | * code duplication in drivers. | |
695 | */ | |
696 | extern int end_that_request_first(struct request *, int, int); | |
697 | extern int end_that_request_chunk(struct request *, int, int); | |
8ffdc655 | 698 | extern void end_that_request_last(struct request *, int); |
1da177e4 | 699 | extern void end_request(struct request *req, int uptodate); |
ff856bad JA |
700 | extern void blk_complete_request(struct request *); |
701 | ||
1da177e4 LT |
702 | /* |
703 | * end_that_request_first/chunk() takes an uptodate argument. we account | |
704 | * any value <= as an io error. 0 means -EIO for compatability reasons, | |
705 | * any other < 0 value is the direct error type. An uptodate value of | |
706 | * 1 indicates successful io completion | |
707 | */ | |
708 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) | |
709 | ||
710 | static inline void blkdev_dequeue_request(struct request *req) | |
711 | { | |
8922e16c | 712 | elv_dequeue_request(req->q, req); |
1da177e4 | 713 | } |
1da177e4 | 714 | |
1da177e4 LT |
715 | /* |
716 | * Access functions for manipulating queue properties | |
717 | */ | |
1946089a CL |
718 | extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, |
719 | spinlock_t *lock, int node_id); | |
1da177e4 LT |
720 | extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); |
721 | extern void blk_cleanup_queue(request_queue_t *); | |
722 | extern void blk_queue_make_request(request_queue_t *, make_request_fn *); | |
723 | extern void blk_queue_bounce_limit(request_queue_t *, u64); | |
2cb2e147 | 724 | extern void blk_queue_max_sectors(request_queue_t *, unsigned int); |
1da177e4 LT |
725 | extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); |
726 | extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); | |
727 | extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); | |
728 | extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); | |
729 | extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); | |
730 | extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); | |
731 | extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); | |
732 | extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); | |
733 | extern void blk_queue_dma_alignment(request_queue_t *, int); | |
ff856bad | 734 | extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *); |
1da177e4 | 735 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); |
797e7dbb | 736 | extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); |
1da177e4 | 737 | extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); |
797e7dbb TH |
738 | extern int blk_do_ordered(request_queue_t *, struct request **); |
739 | extern unsigned blk_ordered_cur_seq(request_queue_t *); | |
740 | extern unsigned blk_ordered_req_seq(struct request *); | |
741 | extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); | |
1da177e4 LT |
742 | |
743 | extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); | |
744 | extern void blk_dump_rq_flags(struct request *, char *); | |
745 | extern void generic_unplug_device(request_queue_t *); | |
746 | extern void __generic_unplug_device(request_queue_t *); | |
747 | extern long nr_blockdev_pages(void); | |
1da177e4 LT |
748 | |
749 | int blk_get_queue(request_queue_t *); | |
8267e268 AV |
750 | request_queue_t *blk_alloc_queue(gfp_t); |
751 | request_queue_t *blk_alloc_queue_node(gfp_t, int); | |
483f4afc | 752 | extern void blk_put_queue(request_queue_t *); |
1da177e4 LT |
753 | |
754 | /* | |
755 | * tag stuff | |
756 | */ | |
757 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) | |
758 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) | |
4aff5e23 | 759 | #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) |
1da177e4 LT |
760 | extern int blk_queue_start_tag(request_queue_t *, struct request *); |
761 | extern struct request *blk_queue_find_tag(request_queue_t *, int); | |
762 | extern void blk_queue_end_tag(request_queue_t *, struct request *); | |
763 | extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); | |
764 | extern void blk_queue_free_tags(request_queue_t *); | |
765 | extern int blk_queue_resize_tags(request_queue_t *, int); | |
766 | extern void blk_queue_invalidate_tags(request_queue_t *); | |
767 | extern long blk_congestion_wait(int rw, long timeout); | |
492dfb48 JB |
768 | extern struct blk_queue_tag *blk_init_tags(int); |
769 | extern void blk_free_tags(struct blk_queue_tag *); | |
275a082f | 770 | extern void blk_congestion_end(int rw); |
1da177e4 LT |
771 | |
772 | extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); | |
773 | extern int blkdev_issue_flush(struct block_device *, sector_t *); | |
774 | ||
775 | #define MAX_PHYS_SEGMENTS 128 | |
776 | #define MAX_HW_SEGMENTS 128 | |
defd94b7 MC |
777 | #define SAFE_MAX_SECTORS 255 |
778 | #define BLK_DEF_MAX_SECTORS 1024 | |
1da177e4 LT |
779 | |
780 | #define MAX_SEGMENT_SIZE 65536 | |
781 | ||
782 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) | |
783 | ||
1da177e4 LT |
784 | static inline int queue_hardsect_size(request_queue_t *q) |
785 | { | |
786 | int retval = 512; | |
787 | ||
788 | if (q && q->hardsect_size) | |
789 | retval = q->hardsect_size; | |
790 | ||
791 | return retval; | |
792 | } | |
793 | ||
794 | static inline int bdev_hardsect_size(struct block_device *bdev) | |
795 | { | |
796 | return queue_hardsect_size(bdev_get_queue(bdev)); | |
797 | } | |
798 | ||
799 | static inline int queue_dma_alignment(request_queue_t *q) | |
800 | { | |
801 | int retval = 511; | |
802 | ||
803 | if (q && q->dma_alignment) | |
804 | retval = q->dma_alignment; | |
805 | ||
806 | return retval; | |
807 | } | |
808 | ||
1da177e4 LT |
809 | /* assumes size > 256 */ |
810 | static inline unsigned int blksize_bits(unsigned int size) | |
811 | { | |
812 | unsigned int bits = 8; | |
813 | do { | |
814 | bits++; | |
815 | size >>= 1; | |
816 | } while (size > 256); | |
817 | return bits; | |
818 | } | |
819 | ||
2befb9e3 | 820 | static inline unsigned int block_size(struct block_device *bdev) |
1da177e4 LT |
821 | { |
822 | return bdev->bd_block_size; | |
823 | } | |
824 | ||
825 | typedef struct {struct page *v;} Sector; | |
826 | ||
827 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); | |
828 | ||
829 | static inline void put_dev_sector(Sector p) | |
830 | { | |
831 | page_cache_release(p.v); | |
832 | } | |
833 | ||
834 | struct work_struct; | |
835 | int kblockd_schedule_work(struct work_struct *work); | |
836 | void kblockd_flush(void); | |
837 | ||
1da177e4 LT |
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 | ||
9361401e DH |
844 | #else /* CONFIG_BLOCK */ |
845 | /* | |
846 | * stubs for when the block layer is configured out | |
847 | */ | |
848 | #define buffer_heads_over_limit 0 | |
849 | ||
850 | static inline long blk_congestion_wait(int rw, long timeout) | |
851 | { | |
bcfd8d36 | 852 | return io_schedule_timeout(timeout); |
9361401e DH |
853 | } |
854 | ||
855 | static inline long nr_blockdev_pages(void) | |
856 | { | |
857 | return 0; | |
858 | } | |
859 | ||
bcfd8d36 AM |
860 | static inline void exit_io_context(void) |
861 | { | |
862 | } | |
9361401e DH |
863 | |
864 | #endif /* CONFIG_BLOCK */ | |
865 | ||
1da177e4 | 866 | #endif |