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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; |
3d6392cf JA |
44 | struct request; |
45 | struct sg_io_hdr; | |
1da177e4 LT |
46 | |
47 | #define BLKDEV_MIN_RQ 4 | |
48 | #define BLKDEV_MAX_RQ 128 /* Default maximum */ | |
49 | ||
50 | /* | |
51 | * This is the per-process anticipatory I/O scheduler state. | |
52 | */ | |
53 | struct as_io_context { | |
54 | spinlock_t lock; | |
55 | ||
56 | void (*dtor)(struct as_io_context *aic); /* destructor */ | |
57 | void (*exit)(struct as_io_context *aic); /* called on task exit */ | |
58 | ||
59 | unsigned long state; | |
60 | atomic_t nr_queued; /* queued reads & sync writes */ | |
61 | atomic_t nr_dispatched; /* number of requests gone to the drivers */ | |
62 | ||
63 | /* IO History tracking */ | |
64 | /* Thinktime */ | |
65 | unsigned long last_end_request; | |
66 | unsigned long ttime_total; | |
67 | unsigned long ttime_samples; | |
68 | unsigned long ttime_mean; | |
69 | /* Layout pattern */ | |
70 | unsigned int seek_samples; | |
71 | sector_t last_request_pos; | |
72 | u64 seek_total; | |
73 | sector_t seek_mean; | |
74 | }; | |
75 | ||
76 | struct cfq_queue; | |
77 | struct cfq_io_context { | |
e2d74ac0 | 78 | struct rb_node rb_node; |
22e2c507 JA |
79 | void *key; |
80 | ||
e2d74ac0 JA |
81 | struct cfq_queue *cfqq[2]; |
82 | ||
22e2c507 JA |
83 | struct io_context *ioc; |
84 | ||
85 | unsigned long last_end_request; | |
206dc69b | 86 | sector_t last_request_pos; |
206dc69b | 87 | |
22e2c507 JA |
88 | unsigned long ttime_total; |
89 | unsigned long ttime_samples; | |
90 | unsigned long ttime_mean; | |
91 | ||
206dc69b JA |
92 | unsigned int seek_samples; |
93 | u64 seek_total; | |
94 | sector_t seek_mean; | |
95 | ||
d9ff4187 AV |
96 | struct list_head queue_list; |
97 | ||
e2d74ac0 JA |
98 | void (*dtor)(struct io_context *); /* destructor */ |
99 | void (*exit)(struct io_context *); /* called on task exit */ | |
1da177e4 LT |
100 | }; |
101 | ||
102 | /* | |
103 | * This is the per-process I/O subsystem state. It is refcounted and | |
104 | * kmalloc'ed. Currently all fields are modified in process io context | |
105 | * (apart from the atomic refcount), so require no locking. | |
106 | */ | |
107 | struct io_context { | |
108 | atomic_t refcount; | |
22e2c507 JA |
109 | struct task_struct *task; |
110 | ||
fc46379d | 111 | unsigned int ioprio_changed; |
1da177e4 LT |
112 | |
113 | /* | |
114 | * For request batching | |
115 | */ | |
116 | unsigned long last_waited; /* Time last woken after wait for request */ | |
117 | int nr_batch_requests; /* Number of requests left in the batch */ | |
118 | ||
1da177e4 | 119 | struct as_io_context *aic; |
e2d74ac0 | 120 | struct rb_root cic_root; |
4e521c27 | 121 | void *ioc_data; |
1da177e4 LT |
122 | }; |
123 | ||
124 | void put_io_context(struct io_context *ioc); | |
125 | void exit_io_context(void); | |
b5deef90 | 126 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
1da177e4 LT |
127 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); |
128 | void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); | |
129 | ||
130 | struct request; | |
8ffdc655 | 131 | typedef void (rq_end_io_fn)(struct request *, int); |
1da177e4 LT |
132 | |
133 | struct request_list { | |
134 | int count[2]; | |
135 | int starved[2]; | |
cb98fc8b | 136 | int elvpriv; |
1da177e4 LT |
137 | mempool_t *rq_pool; |
138 | wait_queue_head_t wait[2]; | |
1da177e4 LT |
139 | }; |
140 | ||
4aff5e23 JA |
141 | /* |
142 | * request command types | |
143 | */ | |
144 | enum rq_cmd_type_bits { | |
145 | REQ_TYPE_FS = 1, /* fs request */ | |
146 | REQ_TYPE_BLOCK_PC, /* scsi command */ | |
147 | REQ_TYPE_SENSE, /* sense request */ | |
148 | REQ_TYPE_PM_SUSPEND, /* suspend request */ | |
149 | REQ_TYPE_PM_RESUME, /* resume request */ | |
150 | REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ | |
151 | REQ_TYPE_FLUSH, /* flush request */ | |
152 | REQ_TYPE_SPECIAL, /* driver defined type */ | |
153 | REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ | |
154 | /* | |
155 | * for ATA/ATAPI devices. this really doesn't belong here, ide should | |
156 | * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver | |
157 | * private REQ_LB opcodes to differentiate what type of request this is | |
158 | */ | |
159 | REQ_TYPE_ATA_CMD, | |
160 | REQ_TYPE_ATA_TASK, | |
161 | REQ_TYPE_ATA_TASKFILE, | |
cea2885a | 162 | REQ_TYPE_ATA_PC, |
4aff5e23 JA |
163 | }; |
164 | ||
165 | /* | |
166 | * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being | |
167 | * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a | |
168 | * SCSI cdb. | |
169 | * | |
170 | * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, | |
171 | * typically to differentiate REQ_TYPE_SPECIAL requests. | |
172 | * | |
173 | */ | |
174 | enum { | |
175 | /* | |
176 | * just examples for now | |
177 | */ | |
178 | REQ_LB_OP_EJECT = 0x40, /* eject request */ | |
179 | REQ_LB_OP_FLUSH = 0x41, /* flush device */ | |
180 | }; | |
181 | ||
182 | /* | |
183 | * request type modified bits. first three bits match BIO_RW* bits, important | |
184 | */ | |
185 | enum rq_flag_bits { | |
186 | __REQ_RW, /* not set, read. set, write */ | |
187 | __REQ_FAILFAST, /* no low level driver retries */ | |
188 | __REQ_SORTED, /* elevator knows about this request */ | |
189 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ | |
190 | __REQ_HARDBARRIER, /* may not be passed by drive either */ | |
191 | __REQ_FUA, /* forced unit access */ | |
192 | __REQ_NOMERGE, /* don't touch this for merging */ | |
193 | __REQ_STARTED, /* drive already may have started this one */ | |
194 | __REQ_DONTPREP, /* don't call prep for this one */ | |
195 | __REQ_QUEUED, /* uses queueing */ | |
196 | __REQ_ELVPRIV, /* elevator private data attached */ | |
197 | __REQ_FAILED, /* set if the request failed */ | |
198 | __REQ_QUIET, /* don't worry about errors */ | |
199 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
200 | __REQ_ORDERED_COLOR, /* is before or after barrier */ | |
201 | __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ | |
49171e5c | 202 | __REQ_ALLOCED, /* request came from our alloc pool */ |
5404bc7a | 203 | __REQ_RW_META, /* metadata io request */ |
4aff5e23 JA |
204 | __REQ_NR_BITS, /* stops here */ |
205 | }; | |
206 | ||
207 | #define REQ_RW (1 << __REQ_RW) | |
208 | #define REQ_FAILFAST (1 << __REQ_FAILFAST) | |
209 | #define REQ_SORTED (1 << __REQ_SORTED) | |
210 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) | |
211 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) | |
212 | #define REQ_FUA (1 << __REQ_FUA) | |
213 | #define REQ_NOMERGE (1 << __REQ_NOMERGE) | |
214 | #define REQ_STARTED (1 << __REQ_STARTED) | |
215 | #define REQ_DONTPREP (1 << __REQ_DONTPREP) | |
216 | #define REQ_QUEUED (1 << __REQ_QUEUED) | |
217 | #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) | |
218 | #define REQ_FAILED (1 << __REQ_FAILED) | |
219 | #define REQ_QUIET (1 << __REQ_QUIET) | |
220 | #define REQ_PREEMPT (1 << __REQ_PREEMPT) | |
221 | #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) | |
222 | #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) | |
49171e5c | 223 | #define REQ_ALLOCED (1 << __REQ_ALLOCED) |
5404bc7a | 224 | #define REQ_RW_META (1 << __REQ_RW_META) |
4aff5e23 | 225 | |
1da177e4 LT |
226 | #define BLK_MAX_CDB 16 |
227 | ||
228 | /* | |
229 | * try to put the fields that are referenced together in the same cacheline | |
230 | */ | |
231 | struct request { | |
ff856bad JA |
232 | struct list_head queuelist; |
233 | struct list_head donelist; | |
234 | ||
e6a1c874 JA |
235 | request_queue_t *q; |
236 | ||
4aff5e23 JA |
237 | unsigned int cmd_flags; |
238 | enum rq_cmd_type_bits cmd_type; | |
1da177e4 LT |
239 | |
240 | /* Maintain bio traversal state for part by part I/O submission. | |
241 | * hard_* are block layer internals, no driver should touch them! | |
242 | */ | |
243 | ||
244 | sector_t sector; /* next sector to submit */ | |
e6a1c874 | 245 | sector_t hard_sector; /* next sector to complete */ |
1da177e4 | 246 | unsigned long nr_sectors; /* no. of sectors left to submit */ |
e6a1c874 | 247 | unsigned long hard_nr_sectors; /* no. of sectors left to complete */ |
1da177e4 LT |
248 | /* no. of sectors left to submit in the current segment */ |
249 | unsigned int current_nr_sectors; | |
250 | ||
1da177e4 LT |
251 | /* no. of sectors left to complete in the current segment */ |
252 | unsigned int hard_cur_sectors; | |
253 | ||
254 | struct bio *bio; | |
255 | struct bio *biotail; | |
256 | ||
9817064b | 257 | struct hlist_node hash; /* merge hash */ |
e6a1c874 JA |
258 | /* |
259 | * The rb_node is only used inside the io scheduler, requests | |
260 | * are pruned when moved to the dispatch queue. So let the | |
261 | * completion_data share space with the rb_node. | |
262 | */ | |
263 | union { | |
264 | struct rb_node rb_node; /* sort/lookup */ | |
265 | void *completion_data; | |
266 | }; | |
9817064b | 267 | |
ff7d145f JA |
268 | /* |
269 | * two pointers are available for the IO schedulers, if they need | |
270 | * more they have to dynamically allocate it. | |
271 | */ | |
1da177e4 | 272 | void *elevator_private; |
ff7d145f JA |
273 | void *elevator_private2; |
274 | ||
8f34ee75 | 275 | struct gendisk *rq_disk; |
1da177e4 LT |
276 | unsigned long start_time; |
277 | ||
278 | /* Number of scatter-gather DMA addr+len pairs after | |
279 | * physical address coalescing is performed. | |
280 | */ | |
281 | unsigned short nr_phys_segments; | |
282 | ||
283 | /* Number of scatter-gather addr+len pairs after | |
284 | * physical and DMA remapping hardware coalescing is performed. | |
285 | * This is the number of scatter-gather entries the driver | |
286 | * will actually have to deal with after DMA mapping is done. | |
287 | */ | |
288 | unsigned short nr_hw_segments; | |
289 | ||
8f34ee75 JA |
290 | unsigned short ioprio; |
291 | ||
1da177e4 | 292 | void *special; |
8f34ee75 | 293 | char *buffer; |
1da177e4 | 294 | |
cdd60262 JA |
295 | int tag; |
296 | int errors; | |
297 | ||
298 | int ref_count; | |
299 | ||
1da177e4 LT |
300 | /* |
301 | * when request is used as a packet command carrier | |
302 | */ | |
303 | unsigned int cmd_len; | |
304 | unsigned char cmd[BLK_MAX_CDB]; | |
305 | ||
306 | unsigned int data_len; | |
1da177e4 | 307 | unsigned int sense_len; |
8f34ee75 | 308 | void *data; |
1da177e4 LT |
309 | void *sense; |
310 | ||
311 | unsigned int timeout; | |
17e01f21 | 312 | int retries; |
1da177e4 | 313 | |
1da177e4 | 314 | /* |
c00895ab | 315 | * completion callback. |
1da177e4 LT |
316 | */ |
317 | rq_end_io_fn *end_io; | |
318 | void *end_io_data; | |
319 | }; | |
320 | ||
321 | /* | |
4aff5e23 | 322 | * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME |
1da177e4 LT |
323 | * requests. Some step values could eventually be made generic. |
324 | */ | |
325 | struct request_pm_state | |
326 | { | |
327 | /* PM state machine step value, currently driver specific */ | |
328 | int pm_step; | |
329 | /* requested PM state value (S1, S2, S3, S4, ...) */ | |
330 | u32 pm_state; | |
331 | void* data; /* for driver use */ | |
332 | }; | |
333 | ||
334 | #include <linux/elevator.h> | |
335 | ||
1da177e4 LT |
336 | typedef void (request_fn_proc) (request_queue_t *q); |
337 | typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); | |
338 | typedef int (prep_rq_fn) (request_queue_t *, struct request *); | |
339 | typedef void (unplug_fn) (request_queue_t *); | |
340 | ||
341 | struct bio_vec; | |
342 | typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); | |
1da177e4 | 343 | typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); |
797e7dbb | 344 | typedef void (prepare_flush_fn) (request_queue_t *, struct request *); |
ff856bad | 345 | typedef void (softirq_done_fn)(struct request *); |
1da177e4 LT |
346 | |
347 | enum blk_queue_state { | |
348 | Queue_down, | |
349 | Queue_up, | |
350 | }; | |
351 | ||
1da177e4 LT |
352 | struct blk_queue_tag { |
353 | struct request **tag_index; /* map of busy tags */ | |
354 | unsigned long *tag_map; /* bit map of free/busy tags */ | |
355 | struct list_head busy_list; /* fifo list of busy tags */ | |
356 | int busy; /* current depth */ | |
357 | int max_depth; /* what we will send to device */ | |
ba025082 | 358 | int real_max_depth; /* what the array can hold */ |
1da177e4 LT |
359 | atomic_t refcnt; /* map can be shared */ |
360 | }; | |
361 | ||
362 | struct request_queue | |
363 | { | |
364 | /* | |
365 | * Together with queue_head for cacheline sharing | |
366 | */ | |
367 | struct list_head queue_head; | |
368 | struct request *last_merge; | |
369 | elevator_t *elevator; | |
370 | ||
371 | /* | |
372 | * the queue request freelist, one for reads and one for writes | |
373 | */ | |
374 | struct request_list rq; | |
375 | ||
376 | request_fn_proc *request_fn; | |
1da177e4 LT |
377 | make_request_fn *make_request_fn; |
378 | prep_rq_fn *prep_rq_fn; | |
379 | unplug_fn *unplug_fn; | |
380 | merge_bvec_fn *merge_bvec_fn; | |
1da177e4 LT |
381 | issue_flush_fn *issue_flush_fn; |
382 | prepare_flush_fn *prepare_flush_fn; | |
ff856bad | 383 | softirq_done_fn *softirq_done_fn; |
1da177e4 | 384 | |
8922e16c TH |
385 | /* |
386 | * Dispatch queue sorting | |
387 | */ | |
1b47f531 | 388 | sector_t end_sector; |
8922e16c | 389 | struct request *boundary_rq; |
8922e16c | 390 | |
1da177e4 LT |
391 | /* |
392 | * Auto-unplugging state | |
393 | */ | |
394 | struct timer_list unplug_timer; | |
395 | int unplug_thresh; /* After this many requests */ | |
396 | unsigned long unplug_delay; /* After this many jiffies */ | |
397 | struct work_struct unplug_work; | |
398 | ||
399 | struct backing_dev_info backing_dev_info; | |
400 | ||
401 | /* | |
402 | * The queue owner gets to use this for whatever they like. | |
403 | * ll_rw_blk doesn't touch it. | |
404 | */ | |
405 | void *queuedata; | |
406 | ||
1da177e4 LT |
407 | /* |
408 | * queue needs bounce pages for pages above this limit | |
409 | */ | |
410 | unsigned long bounce_pfn; | |
8267e268 | 411 | gfp_t bounce_gfp; |
1da177e4 LT |
412 | |
413 | /* | |
414 | * various queue flags, see QUEUE_* below | |
415 | */ | |
416 | unsigned long queue_flags; | |
417 | ||
418 | /* | |
152587de JA |
419 | * protects queue structures from reentrancy. ->__queue_lock should |
420 | * _never_ be used directly, it is queue private. always use | |
421 | * ->queue_lock. | |
1da177e4 | 422 | */ |
152587de | 423 | spinlock_t __queue_lock; |
1da177e4 LT |
424 | spinlock_t *queue_lock; |
425 | ||
426 | /* | |
427 | * queue kobject | |
428 | */ | |
429 | struct kobject kobj; | |
430 | ||
431 | /* | |
432 | * queue settings | |
433 | */ | |
434 | unsigned long nr_requests; /* Max # of requests */ | |
435 | unsigned int nr_congestion_on; | |
436 | unsigned int nr_congestion_off; | |
437 | unsigned int nr_batching; | |
438 | ||
2cb2e147 JA |
439 | unsigned int max_sectors; |
440 | unsigned int max_hw_sectors; | |
1da177e4 LT |
441 | unsigned short max_phys_segments; |
442 | unsigned short max_hw_segments; | |
443 | unsigned short hardsect_size; | |
444 | unsigned int max_segment_size; | |
445 | ||
446 | unsigned long seg_boundary_mask; | |
447 | unsigned int dma_alignment; | |
448 | ||
449 | struct blk_queue_tag *queue_tags; | |
450 | ||
15853af9 | 451 | unsigned int nr_sorted; |
1da177e4 LT |
452 | unsigned int in_flight; |
453 | ||
454 | /* | |
455 | * sg stuff | |
456 | */ | |
457 | unsigned int sg_timeout; | |
458 | unsigned int sg_reserved_size; | |
1946089a | 459 | int node; |
6c5c9341 | 460 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
2056a782 | 461 | struct blk_trace *blk_trace; |
6c5c9341 | 462 | #endif |
1da177e4 LT |
463 | /* |
464 | * reserved for flush operations | |
465 | */ | |
797e7dbb TH |
466 | unsigned int ordered, next_ordered, ordseq; |
467 | int orderr, ordcolor; | |
468 | struct request pre_flush_rq, bar_rq, post_flush_rq; | |
469 | struct request *orig_bar_rq; | |
470 | unsigned int bi_size; | |
483f4afc AV |
471 | |
472 | struct mutex sysfs_lock; | |
1da177e4 LT |
473 | }; |
474 | ||
1da177e4 LT |
475 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ |
476 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ | |
477 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ | |
478 | #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ | |
479 | #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ | |
480 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ | |
481 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ | |
482 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ | |
64521d1a | 483 | #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ |
797e7dbb TH |
484 | |
485 | enum { | |
486 | /* | |
487 | * Hardbarrier is supported with one of the following methods. | |
488 | * | |
489 | * NONE : hardbarrier unsupported | |
490 | * DRAIN : ordering by draining is enough | |
491 | * DRAIN_FLUSH : ordering by draining w/ pre and post flushes | |
492 | * DRAIN_FUA : ordering by draining w/ pre flush and FUA write | |
493 | * TAG : ordering by tag is enough | |
494 | * TAG_FLUSH : ordering by tag w/ pre and post flushes | |
495 | * TAG_FUA : ordering by tag w/ pre flush and FUA write | |
496 | */ | |
497 | QUEUE_ORDERED_NONE = 0x00, | |
498 | QUEUE_ORDERED_DRAIN = 0x01, | |
499 | QUEUE_ORDERED_TAG = 0x02, | |
500 | ||
501 | QUEUE_ORDERED_PREFLUSH = 0x10, | |
502 | QUEUE_ORDERED_POSTFLUSH = 0x20, | |
503 | QUEUE_ORDERED_FUA = 0x40, | |
504 | ||
505 | QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | | |
506 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
507 | QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | | |
508 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
509 | QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | | |
510 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
511 | QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | | |
512 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
513 | ||
514 | /* | |
515 | * Ordered operation sequence | |
516 | */ | |
517 | QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ | |
518 | QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ | |
519 | QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ | |
520 | QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ | |
521 | QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ | |
522 | QUEUE_ORDSEQ_DONE = 0x20, | |
523 | }; | |
1da177e4 LT |
524 | |
525 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) | |
526 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) | |
527 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) | |
797e7dbb | 528 | #define blk_queue_flushing(q) ((q)->ordseq) |
1da177e4 | 529 | |
4aff5e23 JA |
530 | #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) |
531 | #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) | |
532 | #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) | |
533 | #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) | |
534 | ||
535 | #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) | |
536 | #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) | |
1da177e4 LT |
537 | |
538 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) | |
539 | ||
4aff5e23 JA |
540 | #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) |
541 | #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) | |
1da177e4 | 542 | #define blk_pm_request(rq) \ |
4aff5e23 | 543 | (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) |
1da177e4 | 544 | |
4aff5e23 JA |
545 | #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) |
546 | #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) | |
547 | #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) | |
1da177e4 LT |
548 | |
549 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) | |
550 | ||
4aff5e23 | 551 | #define rq_data_dir(rq) ((rq)->cmd_flags & 1) |
1da177e4 | 552 | |
9e2585a8 JA |
553 | /* |
554 | * We regard a request as sync, if it's a READ or a SYNC write. | |
555 | */ | |
556 | #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) | |
5404bc7a | 557 | #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) |
9e2585a8 | 558 | |
1da177e4 LT |
559 | static inline int blk_queue_full(struct request_queue *q, int rw) |
560 | { | |
561 | if (rw == READ) | |
562 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
563 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
564 | } | |
565 | ||
566 | static inline void blk_set_queue_full(struct request_queue *q, int rw) | |
567 | { | |
568 | if (rw == READ) | |
569 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
570 | else | |
571 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
572 | } | |
573 | ||
574 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) | |
575 | { | |
576 | if (rw == READ) | |
577 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
578 | else | |
579 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
580 | } | |
581 | ||
582 | ||
583 | /* | |
584 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may | |
585 | * it already be started by driver. | |
586 | */ | |
587 | #define RQ_NOMERGE_FLAGS \ | |
588 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) | |
589 | #define rq_mergeable(rq) \ | |
4aff5e23 | 590 | (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) |
1da177e4 | 591 | |
1da177e4 LT |
592 | /* |
593 | * q->prep_rq_fn return values | |
594 | */ | |
595 | #define BLKPREP_OK 0 /* serve it */ | |
596 | #define BLKPREP_KILL 1 /* fatal error, kill */ | |
597 | #define BLKPREP_DEFER 2 /* leave on queue */ | |
598 | ||
599 | extern unsigned long blk_max_low_pfn, blk_max_pfn; | |
600 | ||
601 | /* | |
602 | * standard bounce addresses: | |
603 | * | |
604 | * BLK_BOUNCE_HIGH : bounce all highmem pages | |
605 | * BLK_BOUNCE_ANY : don't bounce anything | |
606 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary | |
607 | */ | |
608 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) | |
609 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) | |
610 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) | |
611 | ||
3d6392cf JA |
612 | /* |
613 | * default timeout for SG_IO if none specified | |
614 | */ | |
615 | #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) | |
616 | ||
1da177e4 LT |
617 | #ifdef CONFIG_MMU |
618 | extern int init_emergency_isa_pool(void); | |
619 | extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); | |
620 | #else | |
621 | static inline int init_emergency_isa_pool(void) | |
622 | { | |
623 | return 0; | |
624 | } | |
625 | static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) | |
626 | { | |
627 | } | |
628 | #endif /* CONFIG_MMU */ | |
629 | ||
630 | #define rq_for_each_bio(_bio, rq) \ | |
631 | if ((rq->bio)) \ | |
632 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) | |
633 | ||
1da177e4 LT |
634 | extern int blk_register_queue(struct gendisk *disk); |
635 | extern void blk_unregister_queue(struct gendisk *disk); | |
636 | extern void register_disk(struct gendisk *dev); | |
637 | extern void generic_make_request(struct bio *bio); | |
638 | extern void blk_put_request(struct request *); | |
6e39b69e | 639 | extern void __blk_put_request(request_queue_t *, struct request *); |
8ffdc655 | 640 | extern void blk_end_sync_rq(struct request *rq, int error); |
8267e268 | 641 | extern struct request *blk_get_request(request_queue_t *, int, gfp_t); |
867d1191 | 642 | extern void blk_insert_request(request_queue_t *, struct request *, int, void *); |
1da177e4 LT |
643 | extern void blk_requeue_request(request_queue_t *, struct request *); |
644 | extern void blk_plug_device(request_queue_t *); | |
645 | extern int blk_remove_plug(request_queue_t *); | |
646 | extern void blk_recount_segments(request_queue_t *, struct bio *); | |
1da177e4 | 647 | extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); |
21b2f0c8 CH |
648 | extern int sg_scsi_ioctl(struct file *, struct request_queue *, |
649 | struct gendisk *, struct scsi_ioctl_command __user *); | |
3fcfab16 | 650 | |
1aa4f24f JA |
651 | /* |
652 | * Temporary export, until SCSI gets fixed up. | |
653 | */ | |
654 | extern int ll_back_merge_fn(request_queue_t *, struct request *, struct bio *); | |
655 | ||
3fcfab16 AM |
656 | /* |
657 | * A queue has just exitted congestion. Note this in the global counter of | |
658 | * congested queues, and wake up anyone who was waiting for requests to be | |
659 | * put back. | |
660 | */ | |
661 | static inline void blk_clear_queue_congested(request_queue_t *q, int rw) | |
662 | { | |
663 | clear_bdi_congested(&q->backing_dev_info, rw); | |
664 | } | |
665 | ||
666 | /* | |
667 | * A queue has just entered congestion. Flag that in the queue's VM-visible | |
668 | * state flags and increment the global gounter of congested queues. | |
669 | */ | |
670 | static inline void blk_set_queue_congested(request_queue_t *q, int rw) | |
671 | { | |
672 | set_bdi_congested(&q->backing_dev_info, rw); | |
673 | } | |
674 | ||
1da177e4 LT |
675 | extern void blk_start_queue(request_queue_t *q); |
676 | extern void blk_stop_queue(request_queue_t *q); | |
677 | extern void blk_sync_queue(struct request_queue *q); | |
678 | extern void __blk_stop_queue(request_queue_t *q); | |
679 | extern void blk_run_queue(request_queue_t *); | |
dc72ef4a | 680 | extern void blk_start_queueing(request_queue_t *); |
0e75f906 | 681 | extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned long); |
8e5cfc45 | 682 | extern int blk_rq_unmap_user(struct bio *); |
8267e268 | 683 | extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); |
0e75f906 MC |
684 | extern int blk_rq_map_user_iov(request_queue_t *, struct request *, |
685 | struct sg_iovec *, int, unsigned int); | |
994ca9a1 JB |
686 | extern int blk_execute_rq(request_queue_t *, struct gendisk *, |
687 | struct request *, int); | |
6e39b69e | 688 | extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, |
15fc858a | 689 | struct request *, int, rq_end_io_fn *); |
3d6392cf JA |
690 | extern int blk_fill_sghdr_rq(request_queue_t *, struct request *, |
691 | struct sg_io_hdr *, int); | |
692 | extern int blk_unmap_sghdr_rq(struct request *, struct sg_io_hdr *); | |
693 | extern int blk_complete_sghdr_rq(struct request *, struct sg_io_hdr *, | |
694 | struct bio *); | |
6e39b69e | 695 | |
1da177e4 LT |
696 | static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |
697 | { | |
698 | return bdev->bd_disk->queue; | |
699 | } | |
700 | ||
701 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, | |
702 | struct page *page) | |
703 | { | |
704 | if (bdi && bdi->unplug_io_fn) | |
705 | bdi->unplug_io_fn(bdi, page); | |
706 | } | |
707 | ||
708 | static inline void blk_run_address_space(struct address_space *mapping) | |
709 | { | |
710 | if (mapping) | |
711 | blk_run_backing_dev(mapping->backing_dev_info, NULL); | |
712 | } | |
713 | ||
714 | /* | |
715 | * end_request() and friends. Must be called with the request queue spinlock | |
716 | * acquired. All functions called within end_request() _must_be_ atomic. | |
717 | * | |
718 | * Several drivers define their own end_request and call | |
719 | * end_that_request_first() and end_that_request_last() | |
720 | * for parts of the original function. This prevents | |
721 | * code duplication in drivers. | |
722 | */ | |
723 | extern int end_that_request_first(struct request *, int, int); | |
724 | extern int end_that_request_chunk(struct request *, int, int); | |
8ffdc655 | 725 | extern void end_that_request_last(struct request *, int); |
1da177e4 | 726 | extern void end_request(struct request *req, int uptodate); |
ff856bad JA |
727 | extern void blk_complete_request(struct request *); |
728 | ||
1da177e4 LT |
729 | /* |
730 | * end_that_request_first/chunk() takes an uptodate argument. we account | |
731 | * any value <= as an io error. 0 means -EIO for compatability reasons, | |
732 | * any other < 0 value is the direct error type. An uptodate value of | |
733 | * 1 indicates successful io completion | |
734 | */ | |
735 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) | |
736 | ||
737 | static inline void blkdev_dequeue_request(struct request *req) | |
738 | { | |
8922e16c | 739 | elv_dequeue_request(req->q, req); |
1da177e4 | 740 | } |
1da177e4 | 741 | |
1da177e4 LT |
742 | /* |
743 | * Access functions for manipulating queue properties | |
744 | */ | |
1946089a CL |
745 | extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, |
746 | spinlock_t *lock, int node_id); | |
1da177e4 LT |
747 | extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); |
748 | extern void blk_cleanup_queue(request_queue_t *); | |
749 | extern void blk_queue_make_request(request_queue_t *, make_request_fn *); | |
750 | extern void blk_queue_bounce_limit(request_queue_t *, u64); | |
2cb2e147 | 751 | extern void blk_queue_max_sectors(request_queue_t *, unsigned int); |
1da177e4 LT |
752 | extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); |
753 | extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); | |
754 | extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); | |
755 | extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); | |
756 | extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); | |
757 | extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); | |
758 | extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); | |
759 | extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); | |
760 | extern void blk_queue_dma_alignment(request_queue_t *, int); | |
ff856bad | 761 | extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *); |
1da177e4 | 762 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); |
797e7dbb | 763 | extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); |
1da177e4 | 764 | extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); |
797e7dbb TH |
765 | extern int blk_do_ordered(request_queue_t *, struct request **); |
766 | extern unsigned blk_ordered_cur_seq(request_queue_t *); | |
767 | extern unsigned blk_ordered_req_seq(struct request *); | |
768 | extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); | |
1da177e4 LT |
769 | |
770 | extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); | |
771 | extern void blk_dump_rq_flags(struct request *, char *); | |
772 | extern void generic_unplug_device(request_queue_t *); | |
773 | extern void __generic_unplug_device(request_queue_t *); | |
774 | extern long nr_blockdev_pages(void); | |
1da177e4 LT |
775 | |
776 | int blk_get_queue(request_queue_t *); | |
8267e268 AV |
777 | request_queue_t *blk_alloc_queue(gfp_t); |
778 | request_queue_t *blk_alloc_queue_node(gfp_t, int); | |
483f4afc | 779 | extern void blk_put_queue(request_queue_t *); |
1da177e4 LT |
780 | |
781 | /* | |
782 | * tag stuff | |
783 | */ | |
784 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) | |
785 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) | |
4aff5e23 | 786 | #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) |
1da177e4 LT |
787 | extern int blk_queue_start_tag(request_queue_t *, struct request *); |
788 | extern struct request *blk_queue_find_tag(request_queue_t *, int); | |
789 | extern void blk_queue_end_tag(request_queue_t *, struct request *); | |
790 | extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); | |
791 | extern void blk_queue_free_tags(request_queue_t *); | |
792 | extern int blk_queue_resize_tags(request_queue_t *, int); | |
793 | extern void blk_queue_invalidate_tags(request_queue_t *); | |
492dfb48 JB |
794 | extern struct blk_queue_tag *blk_init_tags(int); |
795 | extern void blk_free_tags(struct blk_queue_tag *); | |
1da177e4 | 796 | |
f583f492 DS |
797 | static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, |
798 | int tag) | |
799 | { | |
800 | if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) | |
801 | return NULL; | |
802 | return bqt->tag_index[tag]; | |
803 | } | |
804 | ||
1da177e4 LT |
805 | extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); |
806 | extern int blkdev_issue_flush(struct block_device *, sector_t *); | |
807 | ||
808 | #define MAX_PHYS_SEGMENTS 128 | |
809 | #define MAX_HW_SEGMENTS 128 | |
defd94b7 MC |
810 | #define SAFE_MAX_SECTORS 255 |
811 | #define BLK_DEF_MAX_SECTORS 1024 | |
1da177e4 LT |
812 | |
813 | #define MAX_SEGMENT_SIZE 65536 | |
814 | ||
815 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) | |
816 | ||
1da177e4 LT |
817 | static inline int queue_hardsect_size(request_queue_t *q) |
818 | { | |
819 | int retval = 512; | |
820 | ||
821 | if (q && q->hardsect_size) | |
822 | retval = q->hardsect_size; | |
823 | ||
824 | return retval; | |
825 | } | |
826 | ||
827 | static inline int bdev_hardsect_size(struct block_device *bdev) | |
828 | { | |
829 | return queue_hardsect_size(bdev_get_queue(bdev)); | |
830 | } | |
831 | ||
832 | static inline int queue_dma_alignment(request_queue_t *q) | |
833 | { | |
834 | int retval = 511; | |
835 | ||
836 | if (q && q->dma_alignment) | |
837 | retval = q->dma_alignment; | |
838 | ||
839 | return retval; | |
840 | } | |
841 | ||
1da177e4 LT |
842 | /* assumes size > 256 */ |
843 | static inline unsigned int blksize_bits(unsigned int size) | |
844 | { | |
845 | unsigned int bits = 8; | |
846 | do { | |
847 | bits++; | |
848 | size >>= 1; | |
849 | } while (size > 256); | |
850 | return bits; | |
851 | } | |
852 | ||
2befb9e3 | 853 | static inline unsigned int block_size(struct block_device *bdev) |
1da177e4 LT |
854 | { |
855 | return bdev->bd_block_size; | |
856 | } | |
857 | ||
858 | typedef struct {struct page *v;} Sector; | |
859 | ||
860 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); | |
861 | ||
862 | static inline void put_dev_sector(Sector p) | |
863 | { | |
864 | page_cache_release(p.v); | |
865 | } | |
866 | ||
867 | struct work_struct; | |
868 | int kblockd_schedule_work(struct work_struct *work); | |
19a75d83 | 869 | void kblockd_flush_work(struct work_struct *work); |
1da177e4 | 870 | |
1da177e4 LT |
871 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ |
872 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) | |
873 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ | |
874 | MODULE_ALIAS("block-major-" __stringify(major) "-*") | |
875 | ||
876 | ||
9361401e DH |
877 | #else /* CONFIG_BLOCK */ |
878 | /* | |
879 | * stubs for when the block layer is configured out | |
880 | */ | |
881 | #define buffer_heads_over_limit 0 | |
882 | ||
9361401e DH |
883 | static inline long nr_blockdev_pages(void) |
884 | { | |
885 | return 0; | |
886 | } | |
887 | ||
bcfd8d36 AM |
888 | static inline void exit_io_context(void) |
889 | { | |
890 | } | |
9361401e DH |
891 | |
892 | #endif /* CONFIG_BLOCK */ | |
893 | ||
1da177e4 | 894 | #endif |