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1da177e4 LT |
1 | #ifndef _LINUX_BLKDEV_H |
2 | #define _LINUX_BLKDEV_H | |
3 | ||
f5ff8422 JA |
4 | #ifdef CONFIG_BLOCK |
5 | ||
bcfd8d36 | 6 | #include <linux/sched.h> |
1da177e4 LT |
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> | |
d351af01 | 19 | #include <linux/bsg.h> |
1da177e4 LT |
20 | |
21 | #include <asm/scatterlist.h> | |
22 | ||
21b2f0c8 CH |
23 | struct scsi_ioctl_command; |
24 | ||
1da177e4 | 25 | struct request_queue; |
71f65e6b | 26 | typedef struct request_queue request_queue_t __deprecated; |
1da177e4 LT |
27 | struct elevator_queue; |
28 | typedef struct elevator_queue elevator_t; | |
29 | struct request_pm_state; | |
2056a782 | 30 | struct blk_trace; |
3d6392cf JA |
31 | struct request; |
32 | struct sg_io_hdr; | |
1da177e4 LT |
33 | |
34 | #define BLKDEV_MIN_RQ 4 | |
35 | #define BLKDEV_MAX_RQ 128 /* Default maximum */ | |
36 | ||
1da177e4 LT |
37 | void put_io_context(struct io_context *ioc); |
38 | void exit_io_context(void); | |
b5deef90 | 39 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
fd0928df | 40 | struct io_context *alloc_io_context(gfp_t gfp_flags, int node); |
1da177e4 LT |
41 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); |
42 | void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); | |
43 | ||
44 | struct request; | |
8ffdc655 | 45 | typedef void (rq_end_io_fn)(struct request *, int); |
1da177e4 LT |
46 | |
47 | struct request_list { | |
48 | int count[2]; | |
49 | int starved[2]; | |
cb98fc8b | 50 | int elvpriv; |
1da177e4 LT |
51 | mempool_t *rq_pool; |
52 | wait_queue_head_t wait[2]; | |
1da177e4 LT |
53 | }; |
54 | ||
4aff5e23 JA |
55 | /* |
56 | * request command types | |
57 | */ | |
58 | enum rq_cmd_type_bits { | |
59 | REQ_TYPE_FS = 1, /* fs request */ | |
60 | REQ_TYPE_BLOCK_PC, /* scsi command */ | |
61 | REQ_TYPE_SENSE, /* sense request */ | |
62 | REQ_TYPE_PM_SUSPEND, /* suspend request */ | |
63 | REQ_TYPE_PM_RESUME, /* resume request */ | |
64 | REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ | |
65 | REQ_TYPE_FLUSH, /* flush request */ | |
66 | REQ_TYPE_SPECIAL, /* driver defined type */ | |
67 | REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ | |
68 | /* | |
69 | * for ATA/ATAPI devices. this really doesn't belong here, ide should | |
70 | * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver | |
71 | * private REQ_LB opcodes to differentiate what type of request this is | |
72 | */ | |
4aff5e23 | 73 | REQ_TYPE_ATA_TASKFILE, |
cea2885a | 74 | REQ_TYPE_ATA_PC, |
4aff5e23 JA |
75 | }; |
76 | ||
77 | /* | |
78 | * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being | |
79 | * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a | |
80 | * SCSI cdb. | |
81 | * | |
82 | * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, | |
83 | * typically to differentiate REQ_TYPE_SPECIAL requests. | |
84 | * | |
85 | */ | |
86 | enum { | |
87 | /* | |
88 | * just examples for now | |
89 | */ | |
90 | REQ_LB_OP_EJECT = 0x40, /* eject request */ | |
91 | REQ_LB_OP_FLUSH = 0x41, /* flush device */ | |
92 | }; | |
93 | ||
94 | /* | |
95 | * request type modified bits. first three bits match BIO_RW* bits, important | |
96 | */ | |
97 | enum rq_flag_bits { | |
98 | __REQ_RW, /* not set, read. set, write */ | |
99 | __REQ_FAILFAST, /* no low level driver retries */ | |
100 | __REQ_SORTED, /* elevator knows about this request */ | |
101 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ | |
102 | __REQ_HARDBARRIER, /* may not be passed by drive either */ | |
103 | __REQ_FUA, /* forced unit access */ | |
104 | __REQ_NOMERGE, /* don't touch this for merging */ | |
105 | __REQ_STARTED, /* drive already may have started this one */ | |
106 | __REQ_DONTPREP, /* don't call prep for this one */ | |
107 | __REQ_QUEUED, /* uses queueing */ | |
108 | __REQ_ELVPRIV, /* elevator private data attached */ | |
109 | __REQ_FAILED, /* set if the request failed */ | |
110 | __REQ_QUIET, /* don't worry about errors */ | |
111 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
112 | __REQ_ORDERED_COLOR, /* is before or after barrier */ | |
113 | __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ | |
49171e5c | 114 | __REQ_ALLOCED, /* request came from our alloc pool */ |
5404bc7a | 115 | __REQ_RW_META, /* metadata io request */ |
4aff5e23 JA |
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) | |
49171e5c | 135 | #define REQ_ALLOCED (1 << __REQ_ALLOCED) |
5404bc7a | 136 | #define REQ_RW_META (1 << __REQ_RW_META) |
4aff5e23 | 137 | |
1da177e4 LT |
138 | #define BLK_MAX_CDB 16 |
139 | ||
140 | /* | |
141 | * try to put the fields that are referenced together in the same cacheline | |
142 | */ | |
143 | struct request { | |
ff856bad JA |
144 | struct list_head queuelist; |
145 | struct list_head donelist; | |
146 | ||
165125e1 | 147 | struct request_queue *q; |
e6a1c874 | 148 | |
4aff5e23 JA |
149 | unsigned int cmd_flags; |
150 | enum rq_cmd_type_bits cmd_type; | |
1da177e4 LT |
151 | |
152 | /* Maintain bio traversal state for part by part I/O submission. | |
153 | * hard_* are block layer internals, no driver should touch them! | |
154 | */ | |
155 | ||
156 | sector_t sector; /* next sector to submit */ | |
e6a1c874 | 157 | sector_t hard_sector; /* next sector to complete */ |
1da177e4 | 158 | unsigned long nr_sectors; /* no. of sectors left to submit */ |
e6a1c874 | 159 | unsigned long hard_nr_sectors; /* no. of sectors left to complete */ |
1da177e4 LT |
160 | /* no. of sectors left to submit in the current segment */ |
161 | unsigned int current_nr_sectors; | |
162 | ||
1da177e4 LT |
163 | /* no. of sectors left to complete in the current segment */ |
164 | unsigned int hard_cur_sectors; | |
165 | ||
166 | struct bio *bio; | |
167 | struct bio *biotail; | |
168 | ||
9817064b | 169 | struct hlist_node hash; /* merge hash */ |
e6a1c874 JA |
170 | /* |
171 | * The rb_node is only used inside the io scheduler, requests | |
172 | * are pruned when moved to the dispatch queue. So let the | |
173 | * completion_data share space with the rb_node. | |
174 | */ | |
175 | union { | |
176 | struct rb_node rb_node; /* sort/lookup */ | |
177 | void *completion_data; | |
178 | }; | |
9817064b | 179 | |
ff7d145f JA |
180 | /* |
181 | * two pointers are available for the IO schedulers, if they need | |
182 | * more they have to dynamically allocate it. | |
183 | */ | |
1da177e4 | 184 | void *elevator_private; |
ff7d145f JA |
185 | void *elevator_private2; |
186 | ||
8f34ee75 | 187 | struct gendisk *rq_disk; |
1da177e4 LT |
188 | unsigned long start_time; |
189 | ||
190 | /* Number of scatter-gather DMA addr+len pairs after | |
191 | * physical address coalescing is performed. | |
192 | */ | |
193 | unsigned short nr_phys_segments; | |
194 | ||
195 | /* Number of scatter-gather addr+len pairs after | |
196 | * physical and DMA remapping hardware coalescing is performed. | |
197 | * This is the number of scatter-gather entries the driver | |
198 | * will actually have to deal with after DMA mapping is done. | |
199 | */ | |
200 | unsigned short nr_hw_segments; | |
201 | ||
8f34ee75 JA |
202 | unsigned short ioprio; |
203 | ||
1da177e4 | 204 | void *special; |
8f34ee75 | 205 | char *buffer; |
1da177e4 | 206 | |
cdd60262 JA |
207 | int tag; |
208 | int errors; | |
209 | ||
210 | int ref_count; | |
211 | ||
1da177e4 LT |
212 | /* |
213 | * when request is used as a packet command carrier | |
214 | */ | |
215 | unsigned int cmd_len; | |
216 | unsigned char cmd[BLK_MAX_CDB]; | |
217 | ||
218 | unsigned int data_len; | |
1da177e4 | 219 | unsigned int sense_len; |
8f34ee75 | 220 | void *data; |
1da177e4 LT |
221 | void *sense; |
222 | ||
223 | unsigned int timeout; | |
17e01f21 | 224 | int retries; |
1da177e4 | 225 | |
1da177e4 | 226 | /* |
c00895ab | 227 | * completion callback. |
1da177e4 LT |
228 | */ |
229 | rq_end_io_fn *end_io; | |
230 | void *end_io_data; | |
abae1fde FT |
231 | |
232 | /* for bidi */ | |
233 | struct request *next_rq; | |
1da177e4 LT |
234 | }; |
235 | ||
236 | /* | |
4aff5e23 | 237 | * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME |
1da177e4 LT |
238 | * requests. Some step values could eventually be made generic. |
239 | */ | |
240 | struct request_pm_state | |
241 | { | |
242 | /* PM state machine step value, currently driver specific */ | |
243 | int pm_step; | |
244 | /* requested PM state value (S1, S2, S3, S4, ...) */ | |
245 | u32 pm_state; | |
246 | void* data; /* for driver use */ | |
247 | }; | |
248 | ||
249 | #include <linux/elevator.h> | |
250 | ||
165125e1 JA |
251 | typedef void (request_fn_proc) (struct request_queue *q); |
252 | typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); | |
253 | typedef int (prep_rq_fn) (struct request_queue *, struct request *); | |
254 | typedef void (unplug_fn) (struct request_queue *); | |
1da177e4 LT |
255 | |
256 | struct bio_vec; | |
165125e1 | 257 | typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *); |
165125e1 | 258 | typedef void (prepare_flush_fn) (struct request_queue *, struct request *); |
ff856bad | 259 | typedef void (softirq_done_fn)(struct request *); |
1da177e4 LT |
260 | |
261 | enum blk_queue_state { | |
262 | Queue_down, | |
263 | Queue_up, | |
264 | }; | |
265 | ||
1da177e4 LT |
266 | struct blk_queue_tag { |
267 | struct request **tag_index; /* map of busy tags */ | |
268 | unsigned long *tag_map; /* bit map of free/busy tags */ | |
1da177e4 LT |
269 | int busy; /* current depth */ |
270 | int max_depth; /* what we will send to device */ | |
ba025082 | 271 | int real_max_depth; /* what the array can hold */ |
1da177e4 LT |
272 | atomic_t refcnt; /* map can be shared */ |
273 | }; | |
274 | ||
275 | struct request_queue | |
276 | { | |
277 | /* | |
278 | * Together with queue_head for cacheline sharing | |
279 | */ | |
280 | struct list_head queue_head; | |
281 | struct request *last_merge; | |
282 | elevator_t *elevator; | |
283 | ||
284 | /* | |
285 | * the queue request freelist, one for reads and one for writes | |
286 | */ | |
287 | struct request_list rq; | |
288 | ||
289 | request_fn_proc *request_fn; | |
1da177e4 LT |
290 | make_request_fn *make_request_fn; |
291 | prep_rq_fn *prep_rq_fn; | |
292 | unplug_fn *unplug_fn; | |
293 | merge_bvec_fn *merge_bvec_fn; | |
1da177e4 | 294 | prepare_flush_fn *prepare_flush_fn; |
ff856bad | 295 | softirq_done_fn *softirq_done_fn; |
1da177e4 | 296 | |
8922e16c TH |
297 | /* |
298 | * Dispatch queue sorting | |
299 | */ | |
1b47f531 | 300 | sector_t end_sector; |
8922e16c | 301 | struct request *boundary_rq; |
8922e16c | 302 | |
1da177e4 LT |
303 | /* |
304 | * Auto-unplugging state | |
305 | */ | |
306 | struct timer_list unplug_timer; | |
307 | int unplug_thresh; /* After this many requests */ | |
308 | unsigned long unplug_delay; /* After this many jiffies */ | |
309 | struct work_struct unplug_work; | |
310 | ||
311 | struct backing_dev_info backing_dev_info; | |
312 | ||
313 | /* | |
314 | * The queue owner gets to use this for whatever they like. | |
315 | * ll_rw_blk doesn't touch it. | |
316 | */ | |
317 | void *queuedata; | |
318 | ||
1da177e4 LT |
319 | /* |
320 | * queue needs bounce pages for pages above this limit | |
321 | */ | |
322 | unsigned long bounce_pfn; | |
8267e268 | 323 | gfp_t bounce_gfp; |
1da177e4 LT |
324 | |
325 | /* | |
326 | * various queue flags, see QUEUE_* below | |
327 | */ | |
328 | unsigned long queue_flags; | |
329 | ||
330 | /* | |
152587de | 331 | * protects queue structures from reentrancy. ->__queue_lock should |
332 | * _never_ be used directly, it is queue private. always use | |
333 | * ->queue_lock. | |
1da177e4 | 334 | */ |
152587de | 335 | spinlock_t __queue_lock; |
1da177e4 LT |
336 | spinlock_t *queue_lock; |
337 | ||
338 | /* | |
339 | * queue kobject | |
340 | */ | |
341 | struct kobject kobj; | |
342 | ||
343 | /* | |
344 | * queue settings | |
345 | */ | |
346 | unsigned long nr_requests; /* Max # of requests */ | |
347 | unsigned int nr_congestion_on; | |
348 | unsigned int nr_congestion_off; | |
349 | unsigned int nr_batching; | |
350 | ||
2cb2e147 JA |
351 | unsigned int max_sectors; |
352 | unsigned int max_hw_sectors; | |
1da177e4 LT |
353 | unsigned short max_phys_segments; |
354 | unsigned short max_hw_segments; | |
355 | unsigned short hardsect_size; | |
356 | unsigned int max_segment_size; | |
357 | ||
358 | unsigned long seg_boundary_mask; | |
359 | unsigned int dma_alignment; | |
360 | ||
361 | struct blk_queue_tag *queue_tags; | |
6eca9004 | 362 | struct list_head tag_busy_list; |
1da177e4 | 363 | |
15853af9 | 364 | unsigned int nr_sorted; |
1da177e4 LT |
365 | unsigned int in_flight; |
366 | ||
367 | /* | |
368 | * sg stuff | |
369 | */ | |
370 | unsigned int sg_timeout; | |
371 | unsigned int sg_reserved_size; | |
1946089a | 372 | int node; |
6c5c9341 | 373 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
2056a782 | 374 | struct blk_trace *blk_trace; |
6c5c9341 | 375 | #endif |
1da177e4 LT |
376 | /* |
377 | * reserved for flush operations | |
378 | */ | |
797e7dbb TH |
379 | unsigned int ordered, next_ordered, ordseq; |
380 | int orderr, ordcolor; | |
381 | struct request pre_flush_rq, bar_rq, post_flush_rq; | |
382 | struct request *orig_bar_rq; | |
483f4afc AV |
383 | |
384 | struct mutex sysfs_lock; | |
d351af01 FT |
385 | |
386 | #if defined(CONFIG_BLK_DEV_BSG) | |
387 | struct bsg_class_device bsg_dev; | |
388 | #endif | |
1da177e4 LT |
389 | }; |
390 | ||
1da177e4 LT |
391 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ |
392 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ | |
393 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ | |
4e97182a QY |
394 | #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */ |
395 | #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */ | |
1da177e4 LT |
396 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ |
397 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ | |
398 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ | |
64521d1a | 399 | #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ |
abae1fde | 400 | #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ |
797e7dbb TH |
401 | |
402 | enum { | |
403 | /* | |
404 | * Hardbarrier is supported with one of the following methods. | |
405 | * | |
406 | * NONE : hardbarrier unsupported | |
407 | * DRAIN : ordering by draining is enough | |
408 | * DRAIN_FLUSH : ordering by draining w/ pre and post flushes | |
409 | * DRAIN_FUA : ordering by draining w/ pre flush and FUA write | |
410 | * TAG : ordering by tag is enough | |
411 | * TAG_FLUSH : ordering by tag w/ pre and post flushes | |
412 | * TAG_FUA : ordering by tag w/ pre flush and FUA write | |
413 | */ | |
414 | QUEUE_ORDERED_NONE = 0x00, | |
415 | QUEUE_ORDERED_DRAIN = 0x01, | |
416 | QUEUE_ORDERED_TAG = 0x02, | |
417 | ||
418 | QUEUE_ORDERED_PREFLUSH = 0x10, | |
419 | QUEUE_ORDERED_POSTFLUSH = 0x20, | |
420 | QUEUE_ORDERED_FUA = 0x40, | |
421 | ||
422 | QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | | |
423 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
424 | QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | | |
425 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
426 | QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | | |
427 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
428 | QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | | |
429 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
430 | ||
431 | /* | |
432 | * Ordered operation sequence | |
433 | */ | |
434 | QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ | |
435 | QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ | |
436 | QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ | |
437 | QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ | |
438 | QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ | |
439 | QUEUE_ORDSEQ_DONE = 0x20, | |
440 | }; | |
1da177e4 LT |
441 | |
442 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) | |
443 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) | |
444 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) | |
797e7dbb | 445 | #define blk_queue_flushing(q) ((q)->ordseq) |
1da177e4 | 446 | |
4aff5e23 JA |
447 | #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) |
448 | #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) | |
449 | #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) | |
450 | #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) | |
451 | ||
452 | #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) | |
453 | #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) | |
1da177e4 LT |
454 | |
455 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) | |
456 | ||
4aff5e23 JA |
457 | #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) |
458 | #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) | |
1da177e4 | 459 | #define blk_pm_request(rq) \ |
4aff5e23 | 460 | (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) |
1da177e4 | 461 | |
4aff5e23 JA |
462 | #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) |
463 | #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) | |
464 | #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) | |
abae1fde | 465 | #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) |
bf2de6f5 | 466 | #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors) |
1da177e4 LT |
467 | |
468 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) | |
469 | ||
4aff5e23 | 470 | #define rq_data_dir(rq) ((rq)->cmd_flags & 1) |
1da177e4 | 471 | |
9e2585a8 JA |
472 | /* |
473 | * We regard a request as sync, if it's a READ or a SYNC write. | |
474 | */ | |
475 | #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) | |
5404bc7a | 476 | #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) |
9e2585a8 | 477 | |
1da177e4 LT |
478 | static inline int blk_queue_full(struct request_queue *q, int rw) |
479 | { | |
480 | if (rw == READ) | |
481 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
482 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
483 | } | |
484 | ||
485 | static inline void blk_set_queue_full(struct request_queue *q, int rw) | |
486 | { | |
487 | if (rw == READ) | |
488 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
489 | else | |
490 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
491 | } | |
492 | ||
493 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) | |
494 | { | |
495 | if (rw == READ) | |
496 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
497 | else | |
498 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
499 | } | |
500 | ||
501 | ||
502 | /* | |
503 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may | |
504 | * it already be started by driver. | |
505 | */ | |
506 | #define RQ_NOMERGE_FLAGS \ | |
507 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) | |
508 | #define rq_mergeable(rq) \ | |
4aff5e23 | 509 | (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) |
1da177e4 | 510 | |
1da177e4 LT |
511 | /* |
512 | * q->prep_rq_fn return values | |
513 | */ | |
514 | #define BLKPREP_OK 0 /* serve it */ | |
515 | #define BLKPREP_KILL 1 /* fatal error, kill */ | |
516 | #define BLKPREP_DEFER 2 /* leave on queue */ | |
517 | ||
518 | extern unsigned long blk_max_low_pfn, blk_max_pfn; | |
519 | ||
520 | /* | |
521 | * standard bounce addresses: | |
522 | * | |
523 | * BLK_BOUNCE_HIGH : bounce all highmem pages | |
524 | * BLK_BOUNCE_ANY : don't bounce anything | |
525 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary | |
526 | */ | |
527 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) | |
528 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) | |
529 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) | |
530 | ||
3d6392cf JA |
531 | /* |
532 | * default timeout for SG_IO if none specified | |
533 | */ | |
534 | #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) | |
535 | ||
2a7326b5 | 536 | #ifdef CONFIG_BOUNCE |
1da177e4 | 537 | extern int init_emergency_isa_pool(void); |
165125e1 | 538 | extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); |
1da177e4 LT |
539 | #else |
540 | static inline int init_emergency_isa_pool(void) | |
541 | { | |
542 | return 0; | |
543 | } | |
165125e1 | 544 | static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) |
1da177e4 LT |
545 | { |
546 | } | |
547 | #endif /* CONFIG_MMU */ | |
548 | ||
5705f702 N |
549 | struct req_iterator { |
550 | int i; | |
551 | struct bio *bio; | |
552 | }; | |
553 | ||
554 | /* This should not be used directly - use rq_for_each_segment */ | |
555 | #define __rq_for_each_bio(_bio, rq) \ | |
1da177e4 LT |
556 | if ((rq->bio)) \ |
557 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) | |
558 | ||
5705f702 N |
559 | #define rq_for_each_segment(bvl, _rq, _iter) \ |
560 | __rq_for_each_bio(_iter.bio, _rq) \ | |
561 | bio_for_each_segment(bvl, _iter.bio, _iter.i) | |
562 | ||
563 | #define rq_iter_last(rq, _iter) \ | |
564 | (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) | |
565 | ||
1da177e4 LT |
566 | extern int blk_register_queue(struct gendisk *disk); |
567 | extern void blk_unregister_queue(struct gendisk *disk); | |
568 | extern void register_disk(struct gendisk *dev); | |
569 | extern void generic_make_request(struct bio *bio); | |
570 | extern void blk_put_request(struct request *); | |
165125e1 | 571 | extern void __blk_put_request(struct request_queue *, struct request *); |
8ffdc655 | 572 | extern void blk_end_sync_rq(struct request *rq, int error); |
165125e1 JA |
573 | extern struct request *blk_get_request(struct request_queue *, int, gfp_t); |
574 | extern void blk_insert_request(struct request_queue *, struct request *, int, void *); | |
575 | extern void blk_requeue_request(struct request_queue *, struct request *); | |
576 | extern void blk_plug_device(struct request_queue *); | |
577 | extern int blk_remove_plug(struct request_queue *); | |
578 | extern void blk_recount_segments(struct request_queue *, struct bio *); | |
45e79a3a FT |
579 | extern int scsi_cmd_ioctl(struct file *, struct request_queue *, |
580 | struct gendisk *, unsigned int, void __user *); | |
21b2f0c8 CH |
581 | extern int sg_scsi_ioctl(struct file *, struct request_queue *, |
582 | struct gendisk *, struct scsi_ioctl_command __user *); | |
3fcfab16 | 583 | |
1aa4f24f JA |
584 | /* |
585 | * Temporary export, until SCSI gets fixed up. | |
586 | */ | |
3001ca77 N |
587 | extern int blk_rq_append_bio(struct request_queue *q, struct request *rq, |
588 | struct bio *bio); | |
1aa4f24f | 589 | |
3fcfab16 AM |
590 | /* |
591 | * A queue has just exitted congestion. Note this in the global counter of | |
592 | * congested queues, and wake up anyone who was waiting for requests to be | |
593 | * put back. | |
594 | */ | |
165125e1 | 595 | static inline void blk_clear_queue_congested(struct request_queue *q, int rw) |
3fcfab16 AM |
596 | { |
597 | clear_bdi_congested(&q->backing_dev_info, rw); | |
598 | } | |
599 | ||
600 | /* | |
601 | * A queue has just entered congestion. Flag that in the queue's VM-visible | |
602 | * state flags and increment the global gounter of congested queues. | |
603 | */ | |
165125e1 | 604 | static inline void blk_set_queue_congested(struct request_queue *q, int rw) |
3fcfab16 AM |
605 | { |
606 | set_bdi_congested(&q->backing_dev_info, rw); | |
607 | } | |
608 | ||
165125e1 JA |
609 | extern void blk_start_queue(struct request_queue *q); |
610 | extern void blk_stop_queue(struct request_queue *q); | |
1da177e4 | 611 | extern void blk_sync_queue(struct request_queue *q); |
165125e1 JA |
612 | extern void __blk_stop_queue(struct request_queue *q); |
613 | extern void blk_run_queue(struct request_queue *); | |
614 | extern void blk_start_queueing(struct request_queue *); | |
615 | extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long); | |
8e5cfc45 | 616 | extern int blk_rq_unmap_user(struct bio *); |
165125e1 JA |
617 | extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); |
618 | extern int blk_rq_map_user_iov(struct request_queue *, struct request *, | |
0e75f906 | 619 | struct sg_iovec *, int, unsigned int); |
165125e1 | 620 | extern int blk_execute_rq(struct request_queue *, struct gendisk *, |
994ca9a1 | 621 | struct request *, int); |
165125e1 | 622 | extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, |
15fc858a | 623 | struct request *, int, rq_end_io_fn *); |
337ad41d | 624 | extern int blk_verify_command(unsigned char *, int); |
2ad8b1ef | 625 | extern void blk_unplug(struct request_queue *q); |
6e39b69e | 626 | |
165125e1 | 627 | static inline struct request_queue *bdev_get_queue(struct block_device *bdev) |
1da177e4 LT |
628 | { |
629 | return bdev->bd_disk->queue; | |
630 | } | |
631 | ||
632 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, | |
633 | struct page *page) | |
634 | { | |
635 | if (bdi && bdi->unplug_io_fn) | |
636 | bdi->unplug_io_fn(bdi, page); | |
637 | } | |
638 | ||
639 | static inline void blk_run_address_space(struct address_space *mapping) | |
640 | { | |
641 | if (mapping) | |
642 | blk_run_backing_dev(mapping->backing_dev_info, NULL); | |
643 | } | |
644 | ||
645 | /* | |
646 | * end_request() and friends. Must be called with the request queue spinlock | |
647 | * acquired. All functions called within end_request() _must_be_ atomic. | |
648 | * | |
649 | * Several drivers define their own end_request and call | |
650 | * end_that_request_first() and end_that_request_last() | |
651 | * for parts of the original function. This prevents | |
652 | * code duplication in drivers. | |
653 | */ | |
654 | extern int end_that_request_first(struct request *, int, int); | |
655 | extern int end_that_request_chunk(struct request *, int, int); | |
8ffdc655 | 656 | extern void end_that_request_last(struct request *, int); |
a0cd1285 JA |
657 | extern void end_request(struct request *, int); |
658 | extern void end_queued_request(struct request *, int); | |
659 | extern void end_dequeued_request(struct request *, int); | |
ff856bad JA |
660 | extern void blk_complete_request(struct request *); |
661 | ||
1da177e4 LT |
662 | /* |
663 | * end_that_request_first/chunk() takes an uptodate argument. we account | |
664 | * any value <= as an io error. 0 means -EIO for compatability reasons, | |
665 | * any other < 0 value is the direct error type. An uptodate value of | |
666 | * 1 indicates successful io completion | |
667 | */ | |
668 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) | |
669 | ||
670 | static inline void blkdev_dequeue_request(struct request *req) | |
671 | { | |
8922e16c | 672 | elv_dequeue_request(req->q, req); |
1da177e4 | 673 | } |
1da177e4 | 674 | |
1da177e4 LT |
675 | /* |
676 | * Access functions for manipulating queue properties | |
677 | */ | |
165125e1 | 678 | extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, |
1946089a | 679 | spinlock_t *lock, int node_id); |
165125e1 JA |
680 | extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); |
681 | extern void blk_cleanup_queue(struct request_queue *); | |
682 | extern void blk_queue_make_request(struct request_queue *, make_request_fn *); | |
683 | extern void blk_queue_bounce_limit(struct request_queue *, u64); | |
684 | extern void blk_queue_max_sectors(struct request_queue *, unsigned int); | |
685 | extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short); | |
686 | extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); | |
687 | extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); | |
688 | extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); | |
689 | extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); | |
690 | extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); | |
691 | extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); | |
692 | extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); | |
693 | extern void blk_queue_dma_alignment(struct request_queue *, int); | |
11c3e689 | 694 | extern void blk_queue_update_dma_alignment(struct request_queue *, int); |
165125e1 | 695 | extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); |
1da177e4 | 696 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); |
165125e1 | 697 | extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); |
165125e1 JA |
698 | extern int blk_do_ordered(struct request_queue *, struct request **); |
699 | extern unsigned blk_ordered_cur_seq(struct request_queue *); | |
797e7dbb | 700 | extern unsigned blk_ordered_req_seq(struct request *); |
165125e1 | 701 | extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); |
1da177e4 | 702 | |
165125e1 | 703 | extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); |
1da177e4 | 704 | extern void blk_dump_rq_flags(struct request *, char *); |
165125e1 JA |
705 | extern void generic_unplug_device(struct request_queue *); |
706 | extern void __generic_unplug_device(struct request_queue *); | |
1da177e4 | 707 | extern long nr_blockdev_pages(void); |
1da177e4 | 708 | |
165125e1 JA |
709 | int blk_get_queue(struct request_queue *); |
710 | struct request_queue *blk_alloc_queue(gfp_t); | |
711 | struct request_queue *blk_alloc_queue_node(gfp_t, int); | |
712 | extern void blk_put_queue(struct request_queue *); | |
1da177e4 LT |
713 | |
714 | /* | |
715 | * tag stuff | |
716 | */ | |
717 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) | |
718 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) | |
4aff5e23 | 719 | #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) |
165125e1 JA |
720 | extern int blk_queue_start_tag(struct request_queue *, struct request *); |
721 | extern struct request *blk_queue_find_tag(struct request_queue *, int); | |
722 | extern void blk_queue_end_tag(struct request_queue *, struct request *); | |
723 | extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); | |
724 | extern void blk_queue_free_tags(struct request_queue *); | |
725 | extern int blk_queue_resize_tags(struct request_queue *, int); | |
726 | extern void blk_queue_invalidate_tags(struct request_queue *); | |
492dfb48 JB |
727 | extern struct blk_queue_tag *blk_init_tags(int); |
728 | extern void blk_free_tags(struct blk_queue_tag *); | |
1da177e4 | 729 | |
f583f492 DS |
730 | static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, |
731 | int tag) | |
732 | { | |
733 | if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) | |
734 | return NULL; | |
735 | return bqt->tag_index[tag]; | |
736 | } | |
737 | ||
1da177e4 LT |
738 | extern int blkdev_issue_flush(struct block_device *, sector_t *); |
739 | ||
740 | #define MAX_PHYS_SEGMENTS 128 | |
741 | #define MAX_HW_SEGMENTS 128 | |
defd94b7 MC |
742 | #define SAFE_MAX_SECTORS 255 |
743 | #define BLK_DEF_MAX_SECTORS 1024 | |
1da177e4 LT |
744 | |
745 | #define MAX_SEGMENT_SIZE 65536 | |
746 | ||
747 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) | |
748 | ||
165125e1 | 749 | static inline int queue_hardsect_size(struct request_queue *q) |
1da177e4 LT |
750 | { |
751 | int retval = 512; | |
752 | ||
753 | if (q && q->hardsect_size) | |
754 | retval = q->hardsect_size; | |
755 | ||
756 | return retval; | |
757 | } | |
758 | ||
759 | static inline int bdev_hardsect_size(struct block_device *bdev) | |
760 | { | |
761 | return queue_hardsect_size(bdev_get_queue(bdev)); | |
762 | } | |
763 | ||
165125e1 | 764 | static inline int queue_dma_alignment(struct request_queue *q) |
1da177e4 LT |
765 | { |
766 | int retval = 511; | |
767 | ||
768 | if (q && q->dma_alignment) | |
769 | retval = q->dma_alignment; | |
770 | ||
771 | return retval; | |
772 | } | |
773 | ||
1da177e4 LT |
774 | /* assumes size > 256 */ |
775 | static inline unsigned int blksize_bits(unsigned int size) | |
776 | { | |
777 | unsigned int bits = 8; | |
778 | do { | |
779 | bits++; | |
780 | size >>= 1; | |
781 | } while (size > 256); | |
782 | return bits; | |
783 | } | |
784 | ||
2befb9e3 | 785 | static inline unsigned int block_size(struct block_device *bdev) |
1da177e4 LT |
786 | { |
787 | return bdev->bd_block_size; | |
788 | } | |
789 | ||
790 | typedef struct {struct page *v;} Sector; | |
791 | ||
792 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); | |
793 | ||
794 | static inline void put_dev_sector(Sector p) | |
795 | { | |
796 | page_cache_release(p.v); | |
797 | } | |
798 | ||
799 | struct work_struct; | |
800 | int kblockd_schedule_work(struct work_struct *work); | |
19a75d83 | 801 | void kblockd_flush_work(struct work_struct *work); |
1da177e4 | 802 | |
1da177e4 LT |
803 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ |
804 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) | |
805 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ | |
806 | MODULE_ALIAS("block-major-" __stringify(major) "-*") | |
807 | ||
808 | ||
9361401e DH |
809 | #else /* CONFIG_BLOCK */ |
810 | /* | |
811 | * stubs for when the block layer is configured out | |
812 | */ | |
813 | #define buffer_heads_over_limit 0 | |
814 | ||
9361401e DH |
815 | static inline long nr_blockdev_pages(void) |
816 | { | |
817 | return 0; | |
818 | } | |
819 | ||
bcfd8d36 AM |
820 | static inline void exit_io_context(void) |
821 | { | |
822 | } | |
9361401e | 823 | |
fd0928df JA |
824 | static inline int put_io_context(struct io_context *ioc) |
825 | { | |
826 | return 1; | |
827 | } | |
828 | ||
829 | ||
9361401e DH |
830 | #endif /* CONFIG_BLOCK */ |
831 | ||
1da177e4 | 832 | #endif |