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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> | |
d351af01 | 17 | #include <linux/bsg.h> |
1da177e4 LT |
18 | |
19 | #include <asm/scatterlist.h> | |
20 | ||
9361401e DH |
21 | #ifdef CONFIG_LBD |
22 | # include <asm/div64.h> | |
23 | # define sector_div(a, b) do_div(a, b) | |
24 | #else | |
25 | # define sector_div(n, b)( \ | |
26 | { \ | |
27 | int _res; \ | |
28 | _res = (n) % (b); \ | |
29 | (n) /= (b); \ | |
30 | _res; \ | |
31 | } \ | |
32 | ) | |
33 | #endif | |
34 | ||
35 | #ifdef CONFIG_BLOCK | |
36 | ||
21b2f0c8 CH |
37 | struct scsi_ioctl_command; |
38 | ||
1da177e4 LT |
39 | struct request_queue; |
40 | typedef struct request_queue request_queue_t; | |
41 | struct elevator_queue; | |
42 | typedef struct elevator_queue elevator_t; | |
43 | struct request_pm_state; | |
2056a782 | 44 | struct blk_trace; |
3d6392cf JA |
45 | struct request; |
46 | struct sg_io_hdr; | |
1da177e4 LT |
47 | |
48 | #define BLKDEV_MIN_RQ 4 | |
49 | #define BLKDEV_MAX_RQ 128 /* Default maximum */ | |
50 | ||
51 | /* | |
52 | * This is the per-process anticipatory I/O scheduler state. | |
53 | */ | |
54 | struct as_io_context { | |
55 | spinlock_t lock; | |
56 | ||
57 | void (*dtor)(struct as_io_context *aic); /* destructor */ | |
58 | void (*exit)(struct as_io_context *aic); /* called on task exit */ | |
59 | ||
60 | unsigned long state; | |
61 | atomic_t nr_queued; /* queued reads & sync writes */ | |
62 | atomic_t nr_dispatched; /* number of requests gone to the drivers */ | |
63 | ||
64 | /* IO History tracking */ | |
65 | /* Thinktime */ | |
66 | unsigned long last_end_request; | |
67 | unsigned long ttime_total; | |
68 | unsigned long ttime_samples; | |
69 | unsigned long ttime_mean; | |
70 | /* Layout pattern */ | |
71 | unsigned int seek_samples; | |
72 | sector_t last_request_pos; | |
73 | u64 seek_total; | |
74 | sector_t seek_mean; | |
75 | }; | |
76 | ||
77 | struct cfq_queue; | |
78 | struct cfq_io_context { | |
e2d74ac0 | 79 | struct rb_node rb_node; |
22e2c507 JA |
80 | void *key; |
81 | ||
e2d74ac0 JA |
82 | struct cfq_queue *cfqq[2]; |
83 | ||
22e2c507 JA |
84 | struct io_context *ioc; |
85 | ||
86 | unsigned long last_end_request; | |
206dc69b | 87 | sector_t last_request_pos; |
206dc69b | 88 | |
22e2c507 JA |
89 | unsigned long ttime_total; |
90 | unsigned long ttime_samples; | |
91 | unsigned long ttime_mean; | |
92 | ||
206dc69b JA |
93 | unsigned int seek_samples; |
94 | u64 seek_total; | |
95 | sector_t seek_mean; | |
96 | ||
d9ff4187 AV |
97 | struct list_head queue_list; |
98 | ||
e2d74ac0 JA |
99 | void (*dtor)(struct io_context *); /* destructor */ |
100 | void (*exit)(struct io_context *); /* called on task exit */ | |
1da177e4 LT |
101 | }; |
102 | ||
103 | /* | |
104 | * This is the per-process I/O subsystem state. It is refcounted and | |
105 | * kmalloc'ed. Currently all fields are modified in process io context | |
106 | * (apart from the atomic refcount), so require no locking. | |
107 | */ | |
108 | struct io_context { | |
109 | atomic_t refcount; | |
22e2c507 JA |
110 | struct task_struct *task; |
111 | ||
fc46379d | 112 | unsigned int ioprio_changed; |
1da177e4 LT |
113 | |
114 | /* | |
115 | * For request batching | |
116 | */ | |
117 | unsigned long last_waited; /* Time last woken after wait for request */ | |
118 | int nr_batch_requests; /* Number of requests left in the batch */ | |
119 | ||
1da177e4 | 120 | struct as_io_context *aic; |
e2d74ac0 | 121 | struct rb_root cic_root; |
4e521c27 | 122 | void *ioc_data; |
1da177e4 LT |
123 | }; |
124 | ||
125 | void put_io_context(struct io_context *ioc); | |
126 | void exit_io_context(void); | |
b5deef90 | 127 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
1da177e4 LT |
128 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); |
129 | void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); | |
130 | ||
131 | struct request; | |
8ffdc655 | 132 | typedef void (rq_end_io_fn)(struct request *, int); |
1da177e4 LT |
133 | |
134 | struct request_list { | |
135 | int count[2]; | |
136 | int starved[2]; | |
cb98fc8b | 137 | int elvpriv; |
1da177e4 LT |
138 | mempool_t *rq_pool; |
139 | wait_queue_head_t wait[2]; | |
1da177e4 LT |
140 | }; |
141 | ||
4aff5e23 JA |
142 | /* |
143 | * request command types | |
144 | */ | |
145 | enum rq_cmd_type_bits { | |
146 | REQ_TYPE_FS = 1, /* fs request */ | |
147 | REQ_TYPE_BLOCK_PC, /* scsi command */ | |
148 | REQ_TYPE_SENSE, /* sense request */ | |
149 | REQ_TYPE_PM_SUSPEND, /* suspend request */ | |
150 | REQ_TYPE_PM_RESUME, /* resume request */ | |
151 | REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ | |
152 | REQ_TYPE_FLUSH, /* flush request */ | |
153 | REQ_TYPE_SPECIAL, /* driver defined type */ | |
154 | REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ | |
155 | /* | |
156 | * for ATA/ATAPI devices. this really doesn't belong here, ide should | |
157 | * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver | |
158 | * private REQ_LB opcodes to differentiate what type of request this is | |
159 | */ | |
160 | REQ_TYPE_ATA_CMD, | |
161 | REQ_TYPE_ATA_TASK, | |
162 | REQ_TYPE_ATA_TASKFILE, | |
cea2885a | 163 | REQ_TYPE_ATA_PC, |
4aff5e23 JA |
164 | }; |
165 | ||
166 | /* | |
167 | * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being | |
168 | * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a | |
169 | * SCSI cdb. | |
170 | * | |
171 | * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, | |
172 | * typically to differentiate REQ_TYPE_SPECIAL requests. | |
173 | * | |
174 | */ | |
175 | enum { | |
176 | /* | |
177 | * just examples for now | |
178 | */ | |
179 | REQ_LB_OP_EJECT = 0x40, /* eject request */ | |
180 | REQ_LB_OP_FLUSH = 0x41, /* flush device */ | |
181 | }; | |
182 | ||
183 | /* | |
184 | * request type modified bits. first three bits match BIO_RW* bits, important | |
185 | */ | |
186 | enum rq_flag_bits { | |
187 | __REQ_RW, /* not set, read. set, write */ | |
188 | __REQ_FAILFAST, /* no low level driver retries */ | |
189 | __REQ_SORTED, /* elevator knows about this request */ | |
190 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ | |
191 | __REQ_HARDBARRIER, /* may not be passed by drive either */ | |
192 | __REQ_FUA, /* forced unit access */ | |
193 | __REQ_NOMERGE, /* don't touch this for merging */ | |
194 | __REQ_STARTED, /* drive already may have started this one */ | |
195 | __REQ_DONTPREP, /* don't call prep for this one */ | |
196 | __REQ_QUEUED, /* uses queueing */ | |
197 | __REQ_ELVPRIV, /* elevator private data attached */ | |
198 | __REQ_FAILED, /* set if the request failed */ | |
199 | __REQ_QUIET, /* don't worry about errors */ | |
200 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
201 | __REQ_ORDERED_COLOR, /* is before or after barrier */ | |
202 | __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ | |
49171e5c | 203 | __REQ_ALLOCED, /* request came from our alloc pool */ |
5404bc7a | 204 | __REQ_RW_META, /* metadata io request */ |
4aff5e23 JA |
205 | __REQ_NR_BITS, /* stops here */ |
206 | }; | |
207 | ||
208 | #define REQ_RW (1 << __REQ_RW) | |
209 | #define REQ_FAILFAST (1 << __REQ_FAILFAST) | |
210 | #define REQ_SORTED (1 << __REQ_SORTED) | |
211 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) | |
212 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) | |
213 | #define REQ_FUA (1 << __REQ_FUA) | |
214 | #define REQ_NOMERGE (1 << __REQ_NOMERGE) | |
215 | #define REQ_STARTED (1 << __REQ_STARTED) | |
216 | #define REQ_DONTPREP (1 << __REQ_DONTPREP) | |
217 | #define REQ_QUEUED (1 << __REQ_QUEUED) | |
218 | #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) | |
219 | #define REQ_FAILED (1 << __REQ_FAILED) | |
220 | #define REQ_QUIET (1 << __REQ_QUIET) | |
221 | #define REQ_PREEMPT (1 << __REQ_PREEMPT) | |
222 | #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) | |
223 | #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) | |
49171e5c | 224 | #define REQ_ALLOCED (1 << __REQ_ALLOCED) |
5404bc7a | 225 | #define REQ_RW_META (1 << __REQ_RW_META) |
4aff5e23 | 226 | |
1da177e4 LT |
227 | #define BLK_MAX_CDB 16 |
228 | ||
229 | /* | |
230 | * try to put the fields that are referenced together in the same cacheline | |
231 | */ | |
232 | struct request { | |
ff856bad JA |
233 | struct list_head queuelist; |
234 | struct list_head donelist; | |
235 | ||
e6a1c874 JA |
236 | request_queue_t *q; |
237 | ||
4aff5e23 JA |
238 | unsigned int cmd_flags; |
239 | enum rq_cmd_type_bits cmd_type; | |
1da177e4 LT |
240 | |
241 | /* Maintain bio traversal state for part by part I/O submission. | |
242 | * hard_* are block layer internals, no driver should touch them! | |
243 | */ | |
244 | ||
245 | sector_t sector; /* next sector to submit */ | |
e6a1c874 | 246 | sector_t hard_sector; /* next sector to complete */ |
1da177e4 | 247 | unsigned long nr_sectors; /* no. of sectors left to submit */ |
e6a1c874 | 248 | unsigned long hard_nr_sectors; /* no. of sectors left to complete */ |
1da177e4 LT |
249 | /* no. of sectors left to submit in the current segment */ |
250 | unsigned int current_nr_sectors; | |
251 | ||
1da177e4 LT |
252 | /* no. of sectors left to complete in the current segment */ |
253 | unsigned int hard_cur_sectors; | |
254 | ||
255 | struct bio *bio; | |
256 | struct bio *biotail; | |
257 | ||
9817064b | 258 | struct hlist_node hash; /* merge hash */ |
e6a1c874 JA |
259 | /* |
260 | * The rb_node is only used inside the io scheduler, requests | |
261 | * are pruned when moved to the dispatch queue. So let the | |
262 | * completion_data share space with the rb_node. | |
263 | */ | |
264 | union { | |
265 | struct rb_node rb_node; /* sort/lookup */ | |
266 | void *completion_data; | |
267 | }; | |
9817064b | 268 | |
ff7d145f JA |
269 | /* |
270 | * two pointers are available for the IO schedulers, if they need | |
271 | * more they have to dynamically allocate it. | |
272 | */ | |
1da177e4 | 273 | void *elevator_private; |
ff7d145f JA |
274 | void *elevator_private2; |
275 | ||
8f34ee75 | 276 | struct gendisk *rq_disk; |
1da177e4 LT |
277 | unsigned long start_time; |
278 | ||
279 | /* Number of scatter-gather DMA addr+len pairs after | |
280 | * physical address coalescing is performed. | |
281 | */ | |
282 | unsigned short nr_phys_segments; | |
283 | ||
284 | /* Number of scatter-gather addr+len pairs after | |
285 | * physical and DMA remapping hardware coalescing is performed. | |
286 | * This is the number of scatter-gather entries the driver | |
287 | * will actually have to deal with after DMA mapping is done. | |
288 | */ | |
289 | unsigned short nr_hw_segments; | |
290 | ||
8f34ee75 JA |
291 | unsigned short ioprio; |
292 | ||
1da177e4 | 293 | void *special; |
8f34ee75 | 294 | char *buffer; |
1da177e4 | 295 | |
cdd60262 JA |
296 | int tag; |
297 | int errors; | |
298 | ||
299 | int ref_count; | |
300 | ||
1da177e4 LT |
301 | /* |
302 | * when request is used as a packet command carrier | |
303 | */ | |
304 | unsigned int cmd_len; | |
305 | unsigned char cmd[BLK_MAX_CDB]; | |
306 | ||
307 | unsigned int data_len; | |
1da177e4 | 308 | unsigned int sense_len; |
8f34ee75 | 309 | void *data; |
1da177e4 LT |
310 | void *sense; |
311 | ||
312 | unsigned int timeout; | |
17e01f21 | 313 | int retries; |
1da177e4 | 314 | |
1da177e4 | 315 | /* |
c00895ab | 316 | * completion callback. |
1da177e4 LT |
317 | */ |
318 | rq_end_io_fn *end_io; | |
319 | void *end_io_data; | |
abae1fde FT |
320 | |
321 | /* for bidi */ | |
322 | struct request *next_rq; | |
1da177e4 LT |
323 | }; |
324 | ||
325 | /* | |
4aff5e23 | 326 | * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME |
1da177e4 LT |
327 | * requests. Some step values could eventually be made generic. |
328 | */ | |
329 | struct request_pm_state | |
330 | { | |
331 | /* PM state machine step value, currently driver specific */ | |
332 | int pm_step; | |
333 | /* requested PM state value (S1, S2, S3, S4, ...) */ | |
334 | u32 pm_state; | |
335 | void* data; /* for driver use */ | |
336 | }; | |
337 | ||
338 | #include <linux/elevator.h> | |
339 | ||
1da177e4 LT |
340 | typedef void (request_fn_proc) (request_queue_t *q); |
341 | typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); | |
342 | typedef int (prep_rq_fn) (request_queue_t *, struct request *); | |
343 | typedef void (unplug_fn) (request_queue_t *); | |
344 | ||
345 | struct bio_vec; | |
346 | typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); | |
1da177e4 | 347 | typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); |
797e7dbb | 348 | typedef void (prepare_flush_fn) (request_queue_t *, struct request *); |
ff856bad | 349 | typedef void (softirq_done_fn)(struct request *); |
1da177e4 LT |
350 | |
351 | enum blk_queue_state { | |
352 | Queue_down, | |
353 | Queue_up, | |
354 | }; | |
355 | ||
1da177e4 LT |
356 | struct blk_queue_tag { |
357 | struct request **tag_index; /* map of busy tags */ | |
358 | unsigned long *tag_map; /* bit map of free/busy tags */ | |
359 | struct list_head busy_list; /* fifo list of busy tags */ | |
360 | int busy; /* current depth */ | |
361 | int max_depth; /* what we will send to device */ | |
ba025082 | 362 | int real_max_depth; /* what the array can hold */ |
1da177e4 LT |
363 | atomic_t refcnt; /* map can be shared */ |
364 | }; | |
365 | ||
366 | struct request_queue | |
367 | { | |
368 | /* | |
369 | * Together with queue_head for cacheline sharing | |
370 | */ | |
371 | struct list_head queue_head; | |
372 | struct request *last_merge; | |
373 | elevator_t *elevator; | |
374 | ||
375 | /* | |
376 | * the queue request freelist, one for reads and one for writes | |
377 | */ | |
378 | struct request_list rq; | |
379 | ||
380 | request_fn_proc *request_fn; | |
1da177e4 LT |
381 | make_request_fn *make_request_fn; |
382 | prep_rq_fn *prep_rq_fn; | |
383 | unplug_fn *unplug_fn; | |
384 | merge_bvec_fn *merge_bvec_fn; | |
1da177e4 LT |
385 | issue_flush_fn *issue_flush_fn; |
386 | prepare_flush_fn *prepare_flush_fn; | |
ff856bad | 387 | softirq_done_fn *softirq_done_fn; |
1da177e4 | 388 | |
8922e16c TH |
389 | /* |
390 | * Dispatch queue sorting | |
391 | */ | |
1b47f531 | 392 | sector_t end_sector; |
8922e16c | 393 | struct request *boundary_rq; |
8922e16c | 394 | |
1da177e4 LT |
395 | /* |
396 | * Auto-unplugging state | |
397 | */ | |
398 | struct timer_list unplug_timer; | |
399 | int unplug_thresh; /* After this many requests */ | |
400 | unsigned long unplug_delay; /* After this many jiffies */ | |
401 | struct work_struct unplug_work; | |
402 | ||
403 | struct backing_dev_info backing_dev_info; | |
404 | ||
405 | /* | |
406 | * The queue owner gets to use this for whatever they like. | |
407 | * ll_rw_blk doesn't touch it. | |
408 | */ | |
409 | void *queuedata; | |
410 | ||
1da177e4 LT |
411 | /* |
412 | * queue needs bounce pages for pages above this limit | |
413 | */ | |
414 | unsigned long bounce_pfn; | |
8267e268 | 415 | gfp_t bounce_gfp; |
1da177e4 LT |
416 | |
417 | /* | |
418 | * various queue flags, see QUEUE_* below | |
419 | */ | |
420 | unsigned long queue_flags; | |
421 | ||
422 | /* | |
152587de JA |
423 | * protects queue structures from reentrancy. ->__queue_lock should |
424 | * _never_ be used directly, it is queue private. always use | |
425 | * ->queue_lock. | |
1da177e4 | 426 | */ |
152587de | 427 | spinlock_t __queue_lock; |
1da177e4 LT |
428 | spinlock_t *queue_lock; |
429 | ||
430 | /* | |
431 | * queue kobject | |
432 | */ | |
433 | struct kobject kobj; | |
434 | ||
435 | /* | |
436 | * queue settings | |
437 | */ | |
438 | unsigned long nr_requests; /* Max # of requests */ | |
439 | unsigned int nr_congestion_on; | |
440 | unsigned int nr_congestion_off; | |
441 | unsigned int nr_batching; | |
442 | ||
2cb2e147 JA |
443 | unsigned int max_sectors; |
444 | unsigned int max_hw_sectors; | |
1da177e4 LT |
445 | unsigned short max_phys_segments; |
446 | unsigned short max_hw_segments; | |
447 | unsigned short hardsect_size; | |
448 | unsigned int max_segment_size; | |
449 | ||
450 | unsigned long seg_boundary_mask; | |
451 | unsigned int dma_alignment; | |
452 | ||
453 | struct blk_queue_tag *queue_tags; | |
454 | ||
15853af9 | 455 | unsigned int nr_sorted; |
1da177e4 LT |
456 | unsigned int in_flight; |
457 | ||
458 | /* | |
459 | * sg stuff | |
460 | */ | |
461 | unsigned int sg_timeout; | |
462 | unsigned int sg_reserved_size; | |
1946089a | 463 | int node; |
6c5c9341 | 464 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
2056a782 | 465 | struct blk_trace *blk_trace; |
6c5c9341 | 466 | #endif |
1da177e4 LT |
467 | /* |
468 | * reserved for flush operations | |
469 | */ | |
797e7dbb TH |
470 | unsigned int ordered, next_ordered, ordseq; |
471 | int orderr, ordcolor; | |
472 | struct request pre_flush_rq, bar_rq, post_flush_rq; | |
473 | struct request *orig_bar_rq; | |
474 | unsigned int bi_size; | |
483f4afc AV |
475 | |
476 | struct mutex sysfs_lock; | |
d351af01 FT |
477 | |
478 | #if defined(CONFIG_BLK_DEV_BSG) | |
479 | struct bsg_class_device bsg_dev; | |
480 | #endif | |
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 */ |
abae1fde | 492 | #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ |
797e7dbb TH |
493 | |
494 | enum { | |
495 | /* | |
496 | * Hardbarrier is supported with one of the following methods. | |
497 | * | |
498 | * NONE : hardbarrier unsupported | |
499 | * DRAIN : ordering by draining is enough | |
500 | * DRAIN_FLUSH : ordering by draining w/ pre and post flushes | |
501 | * DRAIN_FUA : ordering by draining w/ pre flush and FUA write | |
502 | * TAG : ordering by tag is enough | |
503 | * TAG_FLUSH : ordering by tag w/ pre and post flushes | |
504 | * TAG_FUA : ordering by tag w/ pre flush and FUA write | |
505 | */ | |
506 | QUEUE_ORDERED_NONE = 0x00, | |
507 | QUEUE_ORDERED_DRAIN = 0x01, | |
508 | QUEUE_ORDERED_TAG = 0x02, | |
509 | ||
510 | QUEUE_ORDERED_PREFLUSH = 0x10, | |
511 | QUEUE_ORDERED_POSTFLUSH = 0x20, | |
512 | QUEUE_ORDERED_FUA = 0x40, | |
513 | ||
514 | QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | | |
515 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
516 | QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | | |
517 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
518 | QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | | |
519 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
520 | QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | | |
521 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
522 | ||
523 | /* | |
524 | * Ordered operation sequence | |
525 | */ | |
526 | QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ | |
527 | QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ | |
528 | QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ | |
529 | QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ | |
530 | QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ | |
531 | QUEUE_ORDSEQ_DONE = 0x20, | |
532 | }; | |
1da177e4 LT |
533 | |
534 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) | |
535 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) | |
536 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) | |
797e7dbb | 537 | #define blk_queue_flushing(q) ((q)->ordseq) |
1da177e4 | 538 | |
4aff5e23 JA |
539 | #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) |
540 | #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) | |
541 | #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) | |
542 | #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) | |
543 | ||
544 | #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) | |
545 | #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) | |
1da177e4 LT |
546 | |
547 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) | |
548 | ||
4aff5e23 JA |
549 | #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) |
550 | #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) | |
1da177e4 | 551 | #define blk_pm_request(rq) \ |
4aff5e23 | 552 | (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) |
1da177e4 | 553 | |
4aff5e23 JA |
554 | #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) |
555 | #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) | |
556 | #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) | |
abae1fde | 557 | #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) |
1da177e4 LT |
558 | |
559 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) | |
560 | ||
4aff5e23 | 561 | #define rq_data_dir(rq) ((rq)->cmd_flags & 1) |
1da177e4 | 562 | |
9e2585a8 JA |
563 | /* |
564 | * We regard a request as sync, if it's a READ or a SYNC write. | |
565 | */ | |
566 | #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) | |
5404bc7a | 567 | #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) |
9e2585a8 | 568 | |
1da177e4 LT |
569 | static inline int blk_queue_full(struct request_queue *q, int rw) |
570 | { | |
571 | if (rw == READ) | |
572 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
573 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
574 | } | |
575 | ||
576 | static inline void blk_set_queue_full(struct request_queue *q, int rw) | |
577 | { | |
578 | if (rw == READ) | |
579 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
580 | else | |
581 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
582 | } | |
583 | ||
584 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) | |
585 | { | |
586 | if (rw == READ) | |
587 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
588 | else | |
589 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
590 | } | |
591 | ||
592 | ||
593 | /* | |
594 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may | |
595 | * it already be started by driver. | |
596 | */ | |
597 | #define RQ_NOMERGE_FLAGS \ | |
598 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) | |
599 | #define rq_mergeable(rq) \ | |
4aff5e23 | 600 | (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) |
1da177e4 | 601 | |
1da177e4 LT |
602 | /* |
603 | * q->prep_rq_fn return values | |
604 | */ | |
605 | #define BLKPREP_OK 0 /* serve it */ | |
606 | #define BLKPREP_KILL 1 /* fatal error, kill */ | |
607 | #define BLKPREP_DEFER 2 /* leave on queue */ | |
608 | ||
609 | extern unsigned long blk_max_low_pfn, blk_max_pfn; | |
610 | ||
611 | /* | |
612 | * standard bounce addresses: | |
613 | * | |
614 | * BLK_BOUNCE_HIGH : bounce all highmem pages | |
615 | * BLK_BOUNCE_ANY : don't bounce anything | |
616 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary | |
617 | */ | |
618 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) | |
619 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) | |
620 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) | |
621 | ||
3d6392cf JA |
622 | /* |
623 | * default timeout for SG_IO if none specified | |
624 | */ | |
625 | #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) | |
626 | ||
2a7326b5 | 627 | #ifdef CONFIG_BOUNCE |
1da177e4 LT |
628 | extern int init_emergency_isa_pool(void); |
629 | extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); | |
630 | #else | |
631 | static inline int init_emergency_isa_pool(void) | |
632 | { | |
633 | return 0; | |
634 | } | |
635 | static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) | |
636 | { | |
637 | } | |
638 | #endif /* CONFIG_MMU */ | |
639 | ||
640 | #define rq_for_each_bio(_bio, rq) \ | |
641 | if ((rq->bio)) \ | |
642 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) | |
643 | ||
1da177e4 LT |
644 | extern int blk_register_queue(struct gendisk *disk); |
645 | extern void blk_unregister_queue(struct gendisk *disk); | |
646 | extern void register_disk(struct gendisk *dev); | |
647 | extern void generic_make_request(struct bio *bio); | |
648 | extern void blk_put_request(struct request *); | |
6e39b69e | 649 | extern void __blk_put_request(request_queue_t *, struct request *); |
8ffdc655 | 650 | extern void blk_end_sync_rq(struct request *rq, int error); |
8267e268 | 651 | extern struct request *blk_get_request(request_queue_t *, int, gfp_t); |
867d1191 | 652 | extern void blk_insert_request(request_queue_t *, struct request *, int, void *); |
1da177e4 LT |
653 | extern void blk_requeue_request(request_queue_t *, struct request *); |
654 | extern void blk_plug_device(request_queue_t *); | |
655 | extern int blk_remove_plug(request_queue_t *); | |
656 | extern void blk_recount_segments(request_queue_t *, struct bio *); | |
45e79a3a FT |
657 | extern int scsi_cmd_ioctl(struct file *, struct request_queue *, |
658 | struct gendisk *, unsigned int, void __user *); | |
21b2f0c8 CH |
659 | extern int sg_scsi_ioctl(struct file *, struct request_queue *, |
660 | struct gendisk *, struct scsi_ioctl_command __user *); | |
3fcfab16 | 661 | |
1aa4f24f JA |
662 | /* |
663 | * Temporary export, until SCSI gets fixed up. | |
664 | */ | |
665 | extern int ll_back_merge_fn(request_queue_t *, struct request *, struct bio *); | |
666 | ||
3fcfab16 AM |
667 | /* |
668 | * A queue has just exitted congestion. Note this in the global counter of | |
669 | * congested queues, and wake up anyone who was waiting for requests to be | |
670 | * put back. | |
671 | */ | |
672 | static inline void blk_clear_queue_congested(request_queue_t *q, int rw) | |
673 | { | |
674 | clear_bdi_congested(&q->backing_dev_info, rw); | |
675 | } | |
676 | ||
677 | /* | |
678 | * A queue has just entered congestion. Flag that in the queue's VM-visible | |
679 | * state flags and increment the global gounter of congested queues. | |
680 | */ | |
681 | static inline void blk_set_queue_congested(request_queue_t *q, int rw) | |
682 | { | |
683 | set_bdi_congested(&q->backing_dev_info, rw); | |
684 | } | |
685 | ||
1da177e4 LT |
686 | extern void blk_start_queue(request_queue_t *q); |
687 | extern void blk_stop_queue(request_queue_t *q); | |
688 | extern void blk_sync_queue(struct request_queue *q); | |
689 | extern void __blk_stop_queue(request_queue_t *q); | |
690 | extern void blk_run_queue(request_queue_t *); | |
dc72ef4a | 691 | extern void blk_start_queueing(request_queue_t *); |
0e75f906 | 692 | extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned long); |
8e5cfc45 | 693 | extern int blk_rq_unmap_user(struct bio *); |
8267e268 | 694 | extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); |
0e75f906 MC |
695 | extern int blk_rq_map_user_iov(request_queue_t *, struct request *, |
696 | struct sg_iovec *, int, unsigned int); | |
994ca9a1 JB |
697 | extern int blk_execute_rq(request_queue_t *, struct gendisk *, |
698 | struct request *, int); | |
6e39b69e | 699 | extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, |
15fc858a | 700 | struct request *, int, rq_end_io_fn *); |
337ad41d | 701 | extern int blk_verify_command(unsigned char *, int); |
6e39b69e | 702 | |
1da177e4 LT |
703 | static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |
704 | { | |
705 | return bdev->bd_disk->queue; | |
706 | } | |
707 | ||
708 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, | |
709 | struct page *page) | |
710 | { | |
711 | if (bdi && bdi->unplug_io_fn) | |
712 | bdi->unplug_io_fn(bdi, page); | |
713 | } | |
714 | ||
715 | static inline void blk_run_address_space(struct address_space *mapping) | |
716 | { | |
717 | if (mapping) | |
718 | blk_run_backing_dev(mapping->backing_dev_info, NULL); | |
719 | } | |
720 | ||
721 | /* | |
722 | * end_request() and friends. Must be called with the request queue spinlock | |
723 | * acquired. All functions called within end_request() _must_be_ atomic. | |
724 | * | |
725 | * Several drivers define their own end_request and call | |
726 | * end_that_request_first() and end_that_request_last() | |
727 | * for parts of the original function. This prevents | |
728 | * code duplication in drivers. | |
729 | */ | |
730 | extern int end_that_request_first(struct request *, int, int); | |
731 | extern int end_that_request_chunk(struct request *, int, int); | |
8ffdc655 | 732 | extern void end_that_request_last(struct request *, int); |
1da177e4 | 733 | extern void end_request(struct request *req, int uptodate); |
ff856bad JA |
734 | extern void blk_complete_request(struct request *); |
735 | ||
1da177e4 LT |
736 | /* |
737 | * end_that_request_first/chunk() takes an uptodate argument. we account | |
738 | * any value <= as an io error. 0 means -EIO for compatability reasons, | |
739 | * any other < 0 value is the direct error type. An uptodate value of | |
740 | * 1 indicates successful io completion | |
741 | */ | |
742 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) | |
743 | ||
744 | static inline void blkdev_dequeue_request(struct request *req) | |
745 | { | |
8922e16c | 746 | elv_dequeue_request(req->q, req); |
1da177e4 | 747 | } |
1da177e4 | 748 | |
1da177e4 LT |
749 | /* |
750 | * Access functions for manipulating queue properties | |
751 | */ | |
1946089a CL |
752 | extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, |
753 | spinlock_t *lock, int node_id); | |
1da177e4 LT |
754 | extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); |
755 | extern void blk_cleanup_queue(request_queue_t *); | |
756 | extern void blk_queue_make_request(request_queue_t *, make_request_fn *); | |
757 | extern void blk_queue_bounce_limit(request_queue_t *, u64); | |
2cb2e147 | 758 | extern void blk_queue_max_sectors(request_queue_t *, unsigned int); |
1da177e4 LT |
759 | extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); |
760 | extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); | |
761 | extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); | |
762 | extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); | |
763 | extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); | |
764 | extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); | |
765 | extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); | |
766 | extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); | |
767 | extern void blk_queue_dma_alignment(request_queue_t *, int); | |
ff856bad | 768 | extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *); |
1da177e4 | 769 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); |
797e7dbb | 770 | extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); |
1da177e4 | 771 | extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); |
797e7dbb TH |
772 | extern int blk_do_ordered(request_queue_t *, struct request **); |
773 | extern unsigned blk_ordered_cur_seq(request_queue_t *); | |
774 | extern unsigned blk_ordered_req_seq(struct request *); | |
775 | extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); | |
1da177e4 LT |
776 | |
777 | extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); | |
778 | extern void blk_dump_rq_flags(struct request *, char *); | |
779 | extern void generic_unplug_device(request_queue_t *); | |
780 | extern void __generic_unplug_device(request_queue_t *); | |
781 | extern long nr_blockdev_pages(void); | |
1da177e4 LT |
782 | |
783 | int blk_get_queue(request_queue_t *); | |
8267e268 AV |
784 | request_queue_t *blk_alloc_queue(gfp_t); |
785 | request_queue_t *blk_alloc_queue_node(gfp_t, int); | |
483f4afc | 786 | extern void blk_put_queue(request_queue_t *); |
1da177e4 LT |
787 | |
788 | /* | |
789 | * tag stuff | |
790 | */ | |
791 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) | |
792 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) | |
4aff5e23 | 793 | #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) |
1da177e4 LT |
794 | extern int blk_queue_start_tag(request_queue_t *, struct request *); |
795 | extern struct request *blk_queue_find_tag(request_queue_t *, int); | |
796 | extern void blk_queue_end_tag(request_queue_t *, struct request *); | |
797 | extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); | |
798 | extern void blk_queue_free_tags(request_queue_t *); | |
799 | extern int blk_queue_resize_tags(request_queue_t *, int); | |
800 | extern void blk_queue_invalidate_tags(request_queue_t *); | |
492dfb48 JB |
801 | extern struct blk_queue_tag *blk_init_tags(int); |
802 | extern void blk_free_tags(struct blk_queue_tag *); | |
1da177e4 | 803 | |
f583f492 DS |
804 | static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, |
805 | int tag) | |
806 | { | |
807 | if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) | |
808 | return NULL; | |
809 | return bqt->tag_index[tag]; | |
810 | } | |
811 | ||
1da177e4 LT |
812 | extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); |
813 | extern int blkdev_issue_flush(struct block_device *, sector_t *); | |
814 | ||
815 | #define MAX_PHYS_SEGMENTS 128 | |
816 | #define MAX_HW_SEGMENTS 128 | |
defd94b7 MC |
817 | #define SAFE_MAX_SECTORS 255 |
818 | #define BLK_DEF_MAX_SECTORS 1024 | |
1da177e4 LT |
819 | |
820 | #define MAX_SEGMENT_SIZE 65536 | |
821 | ||
822 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) | |
823 | ||
1da177e4 LT |
824 | static inline int queue_hardsect_size(request_queue_t *q) |
825 | { | |
826 | int retval = 512; | |
827 | ||
828 | if (q && q->hardsect_size) | |
829 | retval = q->hardsect_size; | |
830 | ||
831 | return retval; | |
832 | } | |
833 | ||
834 | static inline int bdev_hardsect_size(struct block_device *bdev) | |
835 | { | |
836 | return queue_hardsect_size(bdev_get_queue(bdev)); | |
837 | } | |
838 | ||
839 | static inline int queue_dma_alignment(request_queue_t *q) | |
840 | { | |
841 | int retval = 511; | |
842 | ||
843 | if (q && q->dma_alignment) | |
844 | retval = q->dma_alignment; | |
845 | ||
846 | return retval; | |
847 | } | |
848 | ||
1da177e4 LT |
849 | /* assumes size > 256 */ |
850 | static inline unsigned int blksize_bits(unsigned int size) | |
851 | { | |
852 | unsigned int bits = 8; | |
853 | do { | |
854 | bits++; | |
855 | size >>= 1; | |
856 | } while (size > 256); | |
857 | return bits; | |
858 | } | |
859 | ||
2befb9e3 | 860 | static inline unsigned int block_size(struct block_device *bdev) |
1da177e4 LT |
861 | { |
862 | return bdev->bd_block_size; | |
863 | } | |
864 | ||
865 | typedef struct {struct page *v;} Sector; | |
866 | ||
867 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); | |
868 | ||
869 | static inline void put_dev_sector(Sector p) | |
870 | { | |
871 | page_cache_release(p.v); | |
872 | } | |
873 | ||
874 | struct work_struct; | |
875 | int kblockd_schedule_work(struct work_struct *work); | |
19a75d83 | 876 | void kblockd_flush_work(struct work_struct *work); |
1da177e4 | 877 | |
1da177e4 LT |
878 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ |
879 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) | |
880 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ | |
881 | MODULE_ALIAS("block-major-" __stringify(major) "-*") | |
882 | ||
883 | ||
9361401e DH |
884 | #else /* CONFIG_BLOCK */ |
885 | /* | |
886 | * stubs for when the block layer is configured out | |
887 | */ | |
888 | #define buffer_heads_over_limit 0 | |
889 | ||
9361401e DH |
890 | static inline long nr_blockdev_pages(void) |
891 | { | |
892 | return 0; | |
893 | } | |
894 | ||
bcfd8d36 AM |
895 | static inline void exit_io_context(void) |
896 | { | |
897 | } | |
9361401e DH |
898 | |
899 | #endif /* CONFIG_BLOCK */ | |
900 | ||
1da177e4 | 901 | #endif |