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