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1 | #ifndef _LINUX_BLKDEV_H | |
2 | #define _LINUX_BLKDEV_H | |
3 | ||
4 | #ifdef CONFIG_BLOCK | |
5 | ||
6 | #include <linux/sched.h> | |
7 | #include <linux/major.h> | |
8 | #include <linux/genhd.h> | |
9 | #include <linux/list.h> | |
10 | #include <linux/timer.h> | |
11 | #include <linux/workqueue.h> | |
12 | #include <linux/pagemap.h> | |
13 | #include <linux/backing-dev.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/mempool.h> | |
16 | #include <linux/bio.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/stringify.h> | |
19 | #include <linux/bsg.h> | |
20 | ||
21 | #include <asm/scatterlist.h> | |
22 | ||
23 | struct scsi_ioctl_command; | |
24 | ||
25 | struct request_queue; | |
26 | typedef struct request_queue request_queue_t __deprecated; | |
27 | struct elevator_queue; | |
28 | typedef struct elevator_queue elevator_t; | |
29 | struct request_pm_state; | |
30 | struct blk_trace; | |
31 | struct request; | |
32 | struct sg_io_hdr; | |
33 | ||
34 | #define BLKDEV_MIN_RQ 4 | |
35 | #define BLKDEV_MAX_RQ 128 /* Default maximum */ | |
36 | ||
37 | /* | |
38 | * This is the per-process anticipatory I/O scheduler state. | |
39 | */ | |
40 | struct as_io_context { | |
41 | spinlock_t lock; | |
42 | ||
43 | void (*dtor)(struct as_io_context *aic); /* destructor */ | |
44 | void (*exit)(struct as_io_context *aic); /* called on task exit */ | |
45 | ||
46 | unsigned long state; | |
47 | atomic_t nr_queued; /* queued reads & sync writes */ | |
48 | atomic_t nr_dispatched; /* number of requests gone to the drivers */ | |
49 | ||
50 | /* IO History tracking */ | |
51 | /* Thinktime */ | |
52 | unsigned long last_end_request; | |
53 | unsigned long ttime_total; | |
54 | unsigned long ttime_samples; | |
55 | unsigned long ttime_mean; | |
56 | /* Layout pattern */ | |
57 | unsigned int seek_samples; | |
58 | sector_t last_request_pos; | |
59 | u64 seek_total; | |
60 | sector_t seek_mean; | |
61 | }; | |
62 | ||
63 | struct cfq_queue; | |
64 | struct cfq_io_context { | |
65 | struct rb_node rb_node; | |
66 | void *key; | |
67 | ||
68 | struct cfq_queue *cfqq[2]; | |
69 | ||
70 | struct io_context *ioc; | |
71 | ||
72 | unsigned long last_end_request; | |
73 | sector_t last_request_pos; | |
74 | ||
75 | unsigned long ttime_total; | |
76 | unsigned long ttime_samples; | |
77 | unsigned long ttime_mean; | |
78 | ||
79 | unsigned int seek_samples; | |
80 | u64 seek_total; | |
81 | sector_t seek_mean; | |
82 | ||
83 | struct list_head queue_list; | |
84 | ||
85 | void (*dtor)(struct io_context *); /* destructor */ | |
86 | void (*exit)(struct io_context *); /* called on task exit */ | |
87 | }; | |
88 | ||
89 | /* | |
90 | * This is the per-process I/O subsystem state. It is refcounted and | |
91 | * kmalloc'ed. Currently all fields are modified in process io context | |
92 | * (apart from the atomic refcount), so require no locking. | |
93 | */ | |
94 | struct io_context { | |
95 | atomic_t refcount; | |
96 | struct task_struct *task; | |
97 | ||
98 | unsigned int ioprio_changed; | |
99 | ||
100 | /* | |
101 | * For request batching | |
102 | */ | |
103 | unsigned long last_waited; /* Time last woken after wait for request */ | |
104 | int nr_batch_requests; /* Number of requests left in the batch */ | |
105 | ||
106 | struct as_io_context *aic; | |
107 | struct rb_root cic_root; | |
108 | void *ioc_data; | |
109 | }; | |
110 | ||
111 | void put_io_context(struct io_context *ioc); | |
112 | void exit_io_context(void); | |
113 | struct io_context *get_io_context(gfp_t gfp_flags, int node); | |
114 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); | |
115 | void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); | |
116 | ||
117 | struct request; | |
118 | typedef void (rq_end_io_fn)(struct request *, int); | |
119 | ||
120 | struct request_list { | |
121 | int count[2]; | |
122 | int starved[2]; | |
123 | int elvpriv; | |
124 | mempool_t *rq_pool; | |
125 | wait_queue_head_t wait[2]; | |
126 | }; | |
127 | ||
128 | /* | |
129 | * request command types | |
130 | */ | |
131 | enum rq_cmd_type_bits { | |
132 | REQ_TYPE_FS = 1, /* fs request */ | |
133 | REQ_TYPE_BLOCK_PC, /* scsi command */ | |
134 | REQ_TYPE_SENSE, /* sense request */ | |
135 | REQ_TYPE_PM_SUSPEND, /* suspend request */ | |
136 | REQ_TYPE_PM_RESUME, /* resume request */ | |
137 | REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ | |
138 | REQ_TYPE_FLUSH, /* flush request */ | |
139 | REQ_TYPE_SPECIAL, /* driver defined type */ | |
140 | REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ | |
141 | /* | |
142 | * for ATA/ATAPI devices. this really doesn't belong here, ide should | |
143 | * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver | |
144 | * private REQ_LB opcodes to differentiate what type of request this is | |
145 | */ | |
146 | REQ_TYPE_ATA_CMD, | |
147 | REQ_TYPE_ATA_TASK, | |
148 | REQ_TYPE_ATA_TASKFILE, | |
149 | REQ_TYPE_ATA_PC, | |
150 | }; | |
151 | ||
152 | /* | |
153 | * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being | |
154 | * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a | |
155 | * SCSI cdb. | |
156 | * | |
157 | * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, | |
158 | * typically to differentiate REQ_TYPE_SPECIAL requests. | |
159 | * | |
160 | */ | |
161 | enum { | |
162 | /* | |
163 | * just examples for now | |
164 | */ | |
165 | REQ_LB_OP_EJECT = 0x40, /* eject request */ | |
166 | REQ_LB_OP_FLUSH = 0x41, /* flush device */ | |
167 | }; | |
168 | ||
169 | /* | |
170 | * request type modified bits. first three bits match BIO_RW* bits, important | |
171 | */ | |
172 | enum rq_flag_bits { | |
173 | __REQ_RW, /* not set, read. set, write */ | |
174 | __REQ_FAILFAST, /* no low level driver retries */ | |
175 | __REQ_SORTED, /* elevator knows about this request */ | |
176 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ | |
177 | __REQ_HARDBARRIER, /* may not be passed by drive either */ | |
178 | __REQ_FUA, /* forced unit access */ | |
179 | __REQ_NOMERGE, /* don't touch this for merging */ | |
180 | __REQ_STARTED, /* drive already may have started this one */ | |
181 | __REQ_DONTPREP, /* don't call prep for this one */ | |
182 | __REQ_QUEUED, /* uses queueing */ | |
183 | __REQ_ELVPRIV, /* elevator private data attached */ | |
184 | __REQ_FAILED, /* set if the request failed */ | |
185 | __REQ_QUIET, /* don't worry about errors */ | |
186 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
187 | __REQ_ORDERED_COLOR, /* is before or after barrier */ | |
188 | __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ | |
189 | __REQ_ALLOCED, /* request came from our alloc pool */ | |
190 | __REQ_RW_META, /* metadata io request */ | |
191 | __REQ_NR_BITS, /* stops here */ | |
192 | }; | |
193 | ||
194 | #define REQ_RW (1 << __REQ_RW) | |
195 | #define REQ_FAILFAST (1 << __REQ_FAILFAST) | |
196 | #define REQ_SORTED (1 << __REQ_SORTED) | |
197 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) | |
198 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) | |
199 | #define REQ_FUA (1 << __REQ_FUA) | |
200 | #define REQ_NOMERGE (1 << __REQ_NOMERGE) | |
201 | #define REQ_STARTED (1 << __REQ_STARTED) | |
202 | #define REQ_DONTPREP (1 << __REQ_DONTPREP) | |
203 | #define REQ_QUEUED (1 << __REQ_QUEUED) | |
204 | #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) | |
205 | #define REQ_FAILED (1 << __REQ_FAILED) | |
206 | #define REQ_QUIET (1 << __REQ_QUIET) | |
207 | #define REQ_PREEMPT (1 << __REQ_PREEMPT) | |
208 | #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) | |
209 | #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) | |
210 | #define REQ_ALLOCED (1 << __REQ_ALLOCED) | |
211 | #define REQ_RW_META (1 << __REQ_RW_META) | |
212 | ||
213 | #define BLK_MAX_CDB 16 | |
214 | ||
215 | /* | |
216 | * try to put the fields that are referenced together in the same cacheline | |
217 | */ | |
218 | struct request { | |
219 | struct list_head queuelist; | |
220 | struct list_head donelist; | |
221 | ||
222 | struct request_queue *q; | |
223 | ||
224 | unsigned int cmd_flags; | |
225 | enum rq_cmd_type_bits cmd_type; | |
226 | ||
227 | /* Maintain bio traversal state for part by part I/O submission. | |
228 | * hard_* are block layer internals, no driver should touch them! | |
229 | */ | |
230 | ||
231 | sector_t sector; /* next sector to submit */ | |
232 | sector_t hard_sector; /* next sector to complete */ | |
233 | unsigned long nr_sectors; /* no. of sectors left to submit */ | |
234 | unsigned long hard_nr_sectors; /* no. of sectors left to complete */ | |
235 | /* no. of sectors left to submit in the current segment */ | |
236 | unsigned int current_nr_sectors; | |
237 | ||
238 | /* no. of sectors left to complete in the current segment */ | |
239 | unsigned int hard_cur_sectors; | |
240 | ||
241 | struct bio *bio; | |
242 | struct bio *biotail; | |
243 | ||
244 | struct hlist_node hash; /* merge hash */ | |
245 | /* | |
246 | * The rb_node is only used inside the io scheduler, requests | |
247 | * are pruned when moved to the dispatch queue. So let the | |
248 | * completion_data share space with the rb_node. | |
249 | */ | |
250 | union { | |
251 | struct rb_node rb_node; /* sort/lookup */ | |
252 | void *completion_data; | |
253 | }; | |
254 | ||
255 | /* | |
256 | * two pointers are available for the IO schedulers, if they need | |
257 | * more they have to dynamically allocate it. | |
258 | */ | |
259 | void *elevator_private; | |
260 | void *elevator_private2; | |
261 | ||
262 | struct gendisk *rq_disk; | |
263 | unsigned long start_time; | |
264 | ||
265 | /* Number of scatter-gather DMA addr+len pairs after | |
266 | * physical address coalescing is performed. | |
267 | */ | |
268 | unsigned short nr_phys_segments; | |
269 | ||
270 | /* Number of scatter-gather addr+len pairs after | |
271 | * physical and DMA remapping hardware coalescing is performed. | |
272 | * This is the number of scatter-gather entries the driver | |
273 | * will actually have to deal with after DMA mapping is done. | |
274 | */ | |
275 | unsigned short nr_hw_segments; | |
276 | ||
277 | unsigned short ioprio; | |
278 | ||
279 | void *special; | |
280 | char *buffer; | |
281 | ||
282 | int tag; | |
283 | int errors; | |
284 | ||
285 | int ref_count; | |
286 | ||
287 | /* | |
288 | * when request is used as a packet command carrier | |
289 | */ | |
290 | unsigned int cmd_len; | |
291 | unsigned char cmd[BLK_MAX_CDB]; | |
292 | ||
293 | unsigned int data_len; | |
294 | unsigned int sense_len; | |
295 | void *data; | |
296 | void *sense; | |
297 | ||
298 | unsigned int timeout; | |
299 | int retries; | |
300 | ||
301 | /* | |
302 | * completion callback. | |
303 | */ | |
304 | rq_end_io_fn *end_io; | |
305 | void *end_io_data; | |
306 | ||
307 | /* for bidi */ | |
308 | struct request *next_rq; | |
309 | }; | |
310 | ||
311 | /* | |
312 | * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME | |
313 | * requests. Some step values could eventually be made generic. | |
314 | */ | |
315 | struct request_pm_state | |
316 | { | |
317 | /* PM state machine step value, currently driver specific */ | |
318 | int pm_step; | |
319 | /* requested PM state value (S1, S2, S3, S4, ...) */ | |
320 | u32 pm_state; | |
321 | void* data; /* for driver use */ | |
322 | }; | |
323 | ||
324 | #include <linux/elevator.h> | |
325 | ||
326 | typedef void (request_fn_proc) (struct request_queue *q); | |
327 | typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); | |
328 | typedef int (prep_rq_fn) (struct request_queue *, struct request *); | |
329 | typedef void (unplug_fn) (struct request_queue *); | |
330 | ||
331 | struct bio_vec; | |
332 | typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *); | |
333 | typedef void (prepare_flush_fn) (struct request_queue *, struct request *); | |
334 | typedef void (softirq_done_fn)(struct request *); | |
335 | ||
336 | enum blk_queue_state { | |
337 | Queue_down, | |
338 | Queue_up, | |
339 | }; | |
340 | ||
341 | struct blk_queue_tag { | |
342 | struct request **tag_index; /* map of busy tags */ | |
343 | unsigned long *tag_map; /* bit map of free/busy tags */ | |
344 | struct list_head busy_list; /* fifo list of busy tags */ | |
345 | int busy; /* current depth */ | |
346 | int max_depth; /* what we will send to device */ | |
347 | int real_max_depth; /* what the array can hold */ | |
348 | atomic_t refcnt; /* map can be shared */ | |
349 | }; | |
350 | ||
351 | struct request_queue | |
352 | { | |
353 | /* | |
354 | * Together with queue_head for cacheline sharing | |
355 | */ | |
356 | struct list_head queue_head; | |
357 | struct request *last_merge; | |
358 | elevator_t *elevator; | |
359 | ||
360 | /* | |
361 | * the queue request freelist, one for reads and one for writes | |
362 | */ | |
363 | struct request_list rq; | |
364 | ||
365 | request_fn_proc *request_fn; | |
366 | make_request_fn *make_request_fn; | |
367 | prep_rq_fn *prep_rq_fn; | |
368 | unplug_fn *unplug_fn; | |
369 | merge_bvec_fn *merge_bvec_fn; | |
370 | prepare_flush_fn *prepare_flush_fn; | |
371 | softirq_done_fn *softirq_done_fn; | |
372 | ||
373 | /* | |
374 | * Dispatch queue sorting | |
375 | */ | |
376 | sector_t end_sector; | |
377 | struct request *boundary_rq; | |
378 | ||
379 | /* | |
380 | * Auto-unplugging state | |
381 | */ | |
382 | struct timer_list unplug_timer; | |
383 | int unplug_thresh; /* After this many requests */ | |
384 | unsigned long unplug_delay; /* After this many jiffies */ | |
385 | struct work_struct unplug_work; | |
386 | ||
387 | struct backing_dev_info backing_dev_info; | |
388 | ||
389 | /* | |
390 | * The queue owner gets to use this for whatever they like. | |
391 | * ll_rw_blk doesn't touch it. | |
392 | */ | |
393 | void *queuedata; | |
394 | ||
395 | /* | |
396 | * queue needs bounce pages for pages above this limit | |
397 | */ | |
398 | unsigned long bounce_pfn; | |
399 | gfp_t bounce_gfp; | |
400 | ||
401 | /* | |
402 | * various queue flags, see QUEUE_* below | |
403 | */ | |
404 | unsigned long queue_flags; | |
405 | ||
406 | /* | |
407 | * protects queue structures from reentrancy. ->__queue_lock should | |
408 | * _never_ be used directly, it is queue private. always use | |
409 | * ->queue_lock. | |
410 | */ | |
411 | spinlock_t __queue_lock; | |
412 | spinlock_t *queue_lock; | |
413 | ||
414 | /* | |
415 | * queue kobject | |
416 | */ | |
417 | struct kobject kobj; | |
418 | ||
419 | /* | |
420 | * queue settings | |
421 | */ | |
422 | unsigned long nr_requests; /* Max # of requests */ | |
423 | unsigned int nr_congestion_on; | |
424 | unsigned int nr_congestion_off; | |
425 | unsigned int nr_batching; | |
426 | ||
427 | unsigned int max_sectors; | |
428 | unsigned int max_hw_sectors; | |
429 | unsigned short max_phys_segments; | |
430 | unsigned short max_hw_segments; | |
431 | unsigned short hardsect_size; | |
432 | unsigned int max_segment_size; | |
433 | ||
434 | unsigned long seg_boundary_mask; | |
435 | unsigned int dma_alignment; | |
436 | ||
437 | struct blk_queue_tag *queue_tags; | |
438 | ||
439 | unsigned int nr_sorted; | |
440 | unsigned int in_flight; | |
441 | ||
442 | /* | |
443 | * sg stuff | |
444 | */ | |
445 | unsigned int sg_timeout; | |
446 | unsigned int sg_reserved_size; | |
447 | int node; | |
448 | #ifdef CONFIG_BLK_DEV_IO_TRACE | |
449 | struct blk_trace *blk_trace; | |
450 | #endif | |
451 | /* | |
452 | * reserved for flush operations | |
453 | */ | |
454 | unsigned int ordered, next_ordered, ordseq; | |
455 | int orderr, ordcolor; | |
456 | struct request pre_flush_rq, bar_rq, post_flush_rq; | |
457 | struct request *orig_bar_rq; | |
458 | ||
459 | struct mutex sysfs_lock; | |
460 | ||
461 | #if defined(CONFIG_BLK_DEV_BSG) | |
462 | struct bsg_class_device bsg_dev; | |
463 | #endif | |
464 | }; | |
465 | ||
466 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ | |
467 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ | |
468 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ | |
469 | #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */ | |
470 | #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */ | |
471 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ | |
472 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ | |
473 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ | |
474 | #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ | |
475 | #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ | |
476 | ||
477 | enum { | |
478 | /* | |
479 | * Hardbarrier is supported with one of the following methods. | |
480 | * | |
481 | * NONE : hardbarrier unsupported | |
482 | * DRAIN : ordering by draining is enough | |
483 | * DRAIN_FLUSH : ordering by draining w/ pre and post flushes | |
484 | * DRAIN_FUA : ordering by draining w/ pre flush and FUA write | |
485 | * TAG : ordering by tag is enough | |
486 | * TAG_FLUSH : ordering by tag w/ pre and post flushes | |
487 | * TAG_FUA : ordering by tag w/ pre flush and FUA write | |
488 | */ | |
489 | QUEUE_ORDERED_NONE = 0x00, | |
490 | QUEUE_ORDERED_DRAIN = 0x01, | |
491 | QUEUE_ORDERED_TAG = 0x02, | |
492 | ||
493 | QUEUE_ORDERED_PREFLUSH = 0x10, | |
494 | QUEUE_ORDERED_POSTFLUSH = 0x20, | |
495 | QUEUE_ORDERED_FUA = 0x40, | |
496 | ||
497 | QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | | |
498 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
499 | QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | | |
500 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
501 | QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | | |
502 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
503 | QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | | |
504 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
505 | ||
506 | /* | |
507 | * Ordered operation sequence | |
508 | */ | |
509 | QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ | |
510 | QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ | |
511 | QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ | |
512 | QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ | |
513 | QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ | |
514 | QUEUE_ORDSEQ_DONE = 0x20, | |
515 | }; | |
516 | ||
517 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) | |
518 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) | |
519 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) | |
520 | #define blk_queue_flushing(q) ((q)->ordseq) | |
521 | ||
522 | #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) | |
523 | #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) | |
524 | #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) | |
525 | #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) | |
526 | ||
527 | #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) | |
528 | #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) | |
529 | ||
530 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) | |
531 | ||
532 | #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) | |
533 | #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) | |
534 | #define blk_pm_request(rq) \ | |
535 | (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) | |
536 | ||
537 | #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) | |
538 | #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) | |
539 | #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) | |
540 | #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) | |
541 | #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors) | |
542 | ||
543 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) | |
544 | ||
545 | #define rq_data_dir(rq) ((rq)->cmd_flags & 1) | |
546 | ||
547 | /* | |
548 | * We regard a request as sync, if it's a READ or a SYNC write. | |
549 | */ | |
550 | #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) | |
551 | #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) | |
552 | ||
553 | static inline int blk_queue_full(struct request_queue *q, int rw) | |
554 | { | |
555 | if (rw == READ) | |
556 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
557 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
558 | } | |
559 | ||
560 | static inline void blk_set_queue_full(struct request_queue *q, int rw) | |
561 | { | |
562 | if (rw == READ) | |
563 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
564 | else | |
565 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
566 | } | |
567 | ||
568 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) | |
569 | { | |
570 | if (rw == READ) | |
571 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
572 | else | |
573 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
574 | } | |
575 | ||
576 | ||
577 | /* | |
578 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may | |
579 | * it already be started by driver. | |
580 | */ | |
581 | #define RQ_NOMERGE_FLAGS \ | |
582 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) | |
583 | #define rq_mergeable(rq) \ | |
584 | (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) | |
585 | ||
586 | /* | |
587 | * q->prep_rq_fn return values | |
588 | */ | |
589 | #define BLKPREP_OK 0 /* serve it */ | |
590 | #define BLKPREP_KILL 1 /* fatal error, kill */ | |
591 | #define BLKPREP_DEFER 2 /* leave on queue */ | |
592 | ||
593 | extern unsigned long blk_max_low_pfn, blk_max_pfn; | |
594 | ||
595 | /* | |
596 | * standard bounce addresses: | |
597 | * | |
598 | * BLK_BOUNCE_HIGH : bounce all highmem pages | |
599 | * BLK_BOUNCE_ANY : don't bounce anything | |
600 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary | |
601 | */ | |
602 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) | |
603 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) | |
604 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) | |
605 | ||
606 | /* | |
607 | * default timeout for SG_IO if none specified | |
608 | */ | |
609 | #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) | |
610 | ||
611 | #ifdef CONFIG_BOUNCE | |
612 | extern int init_emergency_isa_pool(void); | |
613 | extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); | |
614 | #else | |
615 | static inline int init_emergency_isa_pool(void) | |
616 | { | |
617 | return 0; | |
618 | } | |
619 | static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) | |
620 | { | |
621 | } | |
622 | #endif /* CONFIG_MMU */ | |
623 | ||
624 | struct req_iterator { | |
625 | int i; | |
626 | struct bio *bio; | |
627 | }; | |
628 | ||
629 | /* This should not be used directly - use rq_for_each_segment */ | |
630 | #define __rq_for_each_bio(_bio, rq) \ | |
631 | if ((rq->bio)) \ | |
632 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) | |
633 | ||
634 | #define rq_for_each_segment(bvl, _rq, _iter) \ | |
635 | __rq_for_each_bio(_iter.bio, _rq) \ | |
636 | bio_for_each_segment(bvl, _iter.bio, _iter.i) | |
637 | ||
638 | #define rq_iter_last(rq, _iter) \ | |
639 | (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) | |
640 | ||
641 | extern int blk_register_queue(struct gendisk *disk); | |
642 | extern void blk_unregister_queue(struct gendisk *disk); | |
643 | extern void register_disk(struct gendisk *dev); | |
644 | extern void generic_make_request(struct bio *bio); | |
645 | extern void blk_put_request(struct request *); | |
646 | extern void __blk_put_request(struct request_queue *, struct request *); | |
647 | extern void blk_end_sync_rq(struct request *rq, int error); | |
648 | extern struct request *blk_get_request(struct request_queue *, int, gfp_t); | |
649 | extern void blk_insert_request(struct request_queue *, struct request *, int, void *); | |
650 | extern void blk_requeue_request(struct request_queue *, struct request *); | |
651 | extern void blk_plug_device(struct request_queue *); | |
652 | extern int blk_remove_plug(struct request_queue *); | |
653 | extern void blk_recount_segments(struct request_queue *, struct bio *); | |
654 | extern int scsi_cmd_ioctl(struct file *, struct request_queue *, | |
655 | struct gendisk *, unsigned int, void __user *); | |
656 | extern int sg_scsi_ioctl(struct file *, struct request_queue *, | |
657 | struct gendisk *, struct scsi_ioctl_command __user *); | |
658 | ||
659 | /* | |
660 | * Temporary export, until SCSI gets fixed up. | |
661 | */ | |
662 | extern int blk_rq_append_bio(struct request_queue *q, struct request *rq, | |
663 | struct bio *bio); | |
664 | ||
665 | /* | |
666 | * A queue has just exitted congestion. Note this in the global counter of | |
667 | * congested queues, and wake up anyone who was waiting for requests to be | |
668 | * put back. | |
669 | */ | |
670 | static inline void blk_clear_queue_congested(struct request_queue *q, int rw) | |
671 | { | |
672 | clear_bdi_congested(&q->backing_dev_info, rw); | |
673 | } | |
674 | ||
675 | /* | |
676 | * A queue has just entered congestion. Flag that in the queue's VM-visible | |
677 | * state flags and increment the global gounter of congested queues. | |
678 | */ | |
679 | static inline void blk_set_queue_congested(struct request_queue *q, int rw) | |
680 | { | |
681 | set_bdi_congested(&q->backing_dev_info, rw); | |
682 | } | |
683 | ||
684 | extern void blk_start_queue(struct request_queue *q); | |
685 | extern void blk_stop_queue(struct request_queue *q); | |
686 | extern void blk_sync_queue(struct request_queue *q); | |
687 | extern void __blk_stop_queue(struct request_queue *q); | |
688 | extern void blk_run_queue(struct request_queue *); | |
689 | extern void blk_start_queueing(struct request_queue *); | |
690 | extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long); | |
691 | extern int blk_rq_unmap_user(struct bio *); | |
692 | extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); | |
693 | extern int blk_rq_map_user_iov(struct request_queue *, struct request *, | |
694 | struct sg_iovec *, int, unsigned int); | |
695 | extern int blk_execute_rq(struct request_queue *, struct gendisk *, | |
696 | struct request *, int); | |
697 | extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, | |
698 | struct request *, int, rq_end_io_fn *); | |
699 | extern int blk_verify_command(unsigned char *, int); | |
700 | ||
701 | static inline struct request_queue *bdev_get_queue(struct block_device *bdev) | |
702 | { | |
703 | return bdev->bd_disk->queue; | |
704 | } | |
705 | ||
706 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, | |
707 | struct page *page) | |
708 | { | |
709 | if (bdi && bdi->unplug_io_fn) | |
710 | bdi->unplug_io_fn(bdi, page); | |
711 | } | |
712 | ||
713 | static inline void blk_run_address_space(struct address_space *mapping) | |
714 | { | |
715 | if (mapping) | |
716 | blk_run_backing_dev(mapping->backing_dev_info, NULL); | |
717 | } | |
718 | ||
719 | /* | |
720 | * end_request() and friends. Must be called with the request queue spinlock | |
721 | * acquired. All functions called within end_request() _must_be_ atomic. | |
722 | * | |
723 | * Several drivers define their own end_request and call | |
724 | * end_that_request_first() and end_that_request_last() | |
725 | * for parts of the original function. This prevents | |
726 | * code duplication in drivers. | |
727 | */ | |
728 | extern int end_that_request_first(struct request *, int, int); | |
729 | extern int end_that_request_chunk(struct request *, int, int); | |
730 | extern void end_that_request_last(struct request *, int); | |
731 | extern void end_request(struct request *, int); | |
732 | extern void end_queued_request(struct request *, int); | |
733 | extern void end_dequeued_request(struct request *, int); | |
734 | extern void blk_complete_request(struct request *); | |
735 | ||
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 | { | |
746 | elv_dequeue_request(req->q, req); | |
747 | } | |
748 | ||
749 | /* | |
750 | * Access functions for manipulating queue properties | |
751 | */ | |
752 | extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, | |
753 | spinlock_t *lock, int node_id); | |
754 | extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); | |
755 | extern void blk_cleanup_queue(struct request_queue *); | |
756 | extern void blk_queue_make_request(struct request_queue *, make_request_fn *); | |
757 | extern void blk_queue_bounce_limit(struct request_queue *, u64); | |
758 | extern void blk_queue_max_sectors(struct request_queue *, unsigned int); | |
759 | extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short); | |
760 | extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); | |
761 | extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); | |
762 | extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); | |
763 | extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); | |
764 | extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); | |
765 | extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); | |
766 | extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); | |
767 | extern void blk_queue_dma_alignment(struct request_queue *, int); | |
768 | extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); | |
769 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); | |
770 | extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); | |
771 | extern int blk_do_ordered(struct request_queue *, struct request **); | |
772 | extern unsigned blk_ordered_cur_seq(struct request_queue *); | |
773 | extern unsigned blk_ordered_req_seq(struct request *); | |
774 | extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); | |
775 | ||
776 | extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); | |
777 | extern void blk_dump_rq_flags(struct request *, char *); | |
778 | extern void generic_unplug_device(struct request_queue *); | |
779 | extern void __generic_unplug_device(struct request_queue *); | |
780 | extern long nr_blockdev_pages(void); | |
781 | ||
782 | int blk_get_queue(struct request_queue *); | |
783 | struct request_queue *blk_alloc_queue(gfp_t); | |
784 | struct request_queue *blk_alloc_queue_node(gfp_t, int); | |
785 | extern void blk_put_queue(struct request_queue *); | |
786 | ||
787 | /* | |
788 | * tag stuff | |
789 | */ | |
790 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) | |
791 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) | |
792 | #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) | |
793 | extern int blk_queue_start_tag(struct request_queue *, struct request *); | |
794 | extern struct request *blk_queue_find_tag(struct request_queue *, int); | |
795 | extern void blk_queue_end_tag(struct request_queue *, struct request *); | |
796 | extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); | |
797 | extern void blk_queue_free_tags(struct request_queue *); | |
798 | extern int blk_queue_resize_tags(struct request_queue *, int); | |
799 | extern void blk_queue_invalidate_tags(struct request_queue *); | |
800 | extern struct blk_queue_tag *blk_init_tags(int); | |
801 | extern void blk_free_tags(struct blk_queue_tag *); | |
802 | ||
803 | static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, | |
804 | int tag) | |
805 | { | |
806 | if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) | |
807 | return NULL; | |
808 | return bqt->tag_index[tag]; | |
809 | } | |
810 | ||
811 | extern int blkdev_issue_flush(struct block_device *, sector_t *); | |
812 | ||
813 | #define MAX_PHYS_SEGMENTS 128 | |
814 | #define MAX_HW_SEGMENTS 128 | |
815 | #define SAFE_MAX_SECTORS 255 | |
816 | #define BLK_DEF_MAX_SECTORS 1024 | |
817 | ||
818 | #define MAX_SEGMENT_SIZE 65536 | |
819 | ||
820 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) | |
821 | ||
822 | static inline int queue_hardsect_size(struct request_queue *q) | |
823 | { | |
824 | int retval = 512; | |
825 | ||
826 | if (q && q->hardsect_size) | |
827 | retval = q->hardsect_size; | |
828 | ||
829 | return retval; | |
830 | } | |
831 | ||
832 | static inline int bdev_hardsect_size(struct block_device *bdev) | |
833 | { | |
834 | return queue_hardsect_size(bdev_get_queue(bdev)); | |
835 | } | |
836 | ||
837 | static inline int queue_dma_alignment(struct request_queue *q) | |
838 | { | |
839 | int retval = 511; | |
840 | ||
841 | if (q && q->dma_alignment) | |
842 | retval = q->dma_alignment; | |
843 | ||
844 | return retval; | |
845 | } | |
846 | ||
847 | /* assumes size > 256 */ | |
848 | static inline unsigned int blksize_bits(unsigned int size) | |
849 | { | |
850 | unsigned int bits = 8; | |
851 | do { | |
852 | bits++; | |
853 | size >>= 1; | |
854 | } while (size > 256); | |
855 | return bits; | |
856 | } | |
857 | ||
858 | static inline unsigned int block_size(struct block_device *bdev) | |
859 | { | |
860 | return bdev->bd_block_size; | |
861 | } | |
862 | ||
863 | typedef struct {struct page *v;} Sector; | |
864 | ||
865 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); | |
866 | ||
867 | static inline void put_dev_sector(Sector p) | |
868 | { | |
869 | page_cache_release(p.v); | |
870 | } | |
871 | ||
872 | struct work_struct; | |
873 | int kblockd_schedule_work(struct work_struct *work); | |
874 | void kblockd_flush_work(struct work_struct *work); | |
875 | ||
876 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ | |
877 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) | |
878 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ | |
879 | MODULE_ALIAS("block-major-" __stringify(major) "-*") | |
880 | ||
881 | ||
882 | #else /* CONFIG_BLOCK */ | |
883 | /* | |
884 | * stubs for when the block layer is configured out | |
885 | */ | |
886 | #define buffer_heads_over_limit 0 | |
887 | ||
888 | static inline long nr_blockdev_pages(void) | |
889 | { | |
890 | return 0; | |
891 | } | |
892 | ||
893 | static inline void exit_io_context(void) | |
894 | { | |
895 | } | |
896 | ||
897 | #endif /* CONFIG_BLOCK */ | |
898 | ||
899 | #endif |