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Merge branch 'audit.b62' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit...
[thirdparty/linux.git] / include / linux / blkdev.h
... / ...
CommitLineData
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/gfp.h>
20#include <linux/bsg.h>
21#include <linux/smp.h>
22
23#include <asm/scatterlist.h>
24
25struct scsi_ioctl_command;
26
27struct request_queue;
28struct elevator_queue;
29struct request_pm_state;
30struct blk_trace;
31struct request;
32struct sg_io_hdr;
33
34#define BLKDEV_MIN_RQ 4
35#define BLKDEV_MAX_RQ 128 /* Default maximum */
36
37struct request;
38typedef void (rq_end_io_fn)(struct request *, int);
39
40struct request_list {
41 int count[2];
42 int starved[2];
43 int elvpriv;
44 mempool_t *rq_pool;
45 wait_queue_head_t wait[2];
46};
47
48/*
49 * request command types
50 */
51enum rq_cmd_type_bits {
52 REQ_TYPE_FS = 1, /* fs request */
53 REQ_TYPE_BLOCK_PC, /* scsi command */
54 REQ_TYPE_SENSE, /* sense request */
55 REQ_TYPE_PM_SUSPEND, /* suspend request */
56 REQ_TYPE_PM_RESUME, /* resume request */
57 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
58 REQ_TYPE_SPECIAL, /* driver defined type */
59 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
60 /*
61 * for ATA/ATAPI devices. this really doesn't belong here, ide should
62 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
63 * private REQ_LB opcodes to differentiate what type of request this is
64 */
65 REQ_TYPE_ATA_TASKFILE,
66 REQ_TYPE_ATA_PC,
67};
68
69/*
70 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
71 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
72 * SCSI cdb.
73 *
74 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
75 * typically to differentiate REQ_TYPE_SPECIAL requests.
76 *
77 */
78enum {
79 REQ_LB_OP_EJECT = 0x40, /* eject request */
80 REQ_LB_OP_FLUSH = 0x41, /* flush request */
81 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
82};
83
84/*
85 * request type modified bits. first two bits match BIO_RW* bits, important
86 */
87enum rq_flag_bits {
88 __REQ_RW, /* not set, read. set, write */
89 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
90 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
91 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
92 __REQ_DISCARD, /* request to discard sectors */
93 __REQ_SORTED, /* elevator knows about this request */
94 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
95 __REQ_HARDBARRIER, /* may not be passed by drive either */
96 __REQ_FUA, /* forced unit access */
97 __REQ_NOMERGE, /* don't touch this for merging */
98 __REQ_STARTED, /* drive already may have started this one */
99 __REQ_DONTPREP, /* don't call prep for this one */
100 __REQ_QUEUED, /* uses queueing */
101 __REQ_ELVPRIV, /* elevator private data attached */
102 __REQ_FAILED, /* set if the request failed */
103 __REQ_QUIET, /* don't worry about errors */
104 __REQ_PREEMPT, /* set for "ide_preempt" requests */
105 __REQ_ORDERED_COLOR, /* is before or after barrier */
106 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
107 __REQ_ALLOCED, /* request came from our alloc pool */
108 __REQ_RW_META, /* metadata io request */
109 __REQ_COPY_USER, /* contains copies of user pages */
110 __REQ_INTEGRITY, /* integrity metadata has been remapped */
111 __REQ_UNPLUG, /* unplug queue on submission */
112 __REQ_NR_BITS, /* stops here */
113};
114
115#define REQ_RW (1 << __REQ_RW)
116#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
117#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
118#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
119#define REQ_DISCARD (1 << __REQ_DISCARD)
120#define REQ_SORTED (1 << __REQ_SORTED)
121#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
122#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
123#define REQ_FUA (1 << __REQ_FUA)
124#define REQ_NOMERGE (1 << __REQ_NOMERGE)
125#define REQ_STARTED (1 << __REQ_STARTED)
126#define REQ_DONTPREP (1 << __REQ_DONTPREP)
127#define REQ_QUEUED (1 << __REQ_QUEUED)
128#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
129#define REQ_FAILED (1 << __REQ_FAILED)
130#define REQ_QUIET (1 << __REQ_QUIET)
131#define REQ_PREEMPT (1 << __REQ_PREEMPT)
132#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
133#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
134#define REQ_ALLOCED (1 << __REQ_ALLOCED)
135#define REQ_RW_META (1 << __REQ_RW_META)
136#define REQ_COPY_USER (1 << __REQ_COPY_USER)
137#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
138#define REQ_UNPLUG (1 << __REQ_UNPLUG)
139
140#define BLK_MAX_CDB 16
141
142/*
143 * try to put the fields that are referenced together in the same cacheline.
144 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
145 * as well!
146 */
147struct request {
148 struct list_head queuelist;
149 struct call_single_data csd;
150 int cpu;
151
152 struct request_queue *q;
153
154 unsigned int cmd_flags;
155 enum rq_cmd_type_bits cmd_type;
156 unsigned long atomic_flags;
157
158 /* Maintain bio traversal state for part by part I/O submission.
159 * hard_* are block layer internals, no driver should touch them!
160 */
161
162 sector_t sector; /* next sector to submit */
163 sector_t hard_sector; /* next sector to complete */
164 unsigned long nr_sectors; /* no. of sectors left to submit */
165 unsigned long hard_nr_sectors; /* no. of sectors left to complete */
166 /* no. of sectors left to submit in the current segment */
167 unsigned int current_nr_sectors;
168
169 /* no. of sectors left to complete in the current segment */
170 unsigned int hard_cur_sectors;
171
172 struct bio *bio;
173 struct bio *biotail;
174
175 struct hlist_node hash; /* merge hash */
176 /*
177 * The rb_node is only used inside the io scheduler, requests
178 * are pruned when moved to the dispatch queue. So let the
179 * completion_data share space with the rb_node.
180 */
181 union {
182 struct rb_node rb_node; /* sort/lookup */
183 void *completion_data;
184 };
185
186 /*
187 * two pointers are available for the IO schedulers, if they need
188 * more they have to dynamically allocate it.
189 */
190 void *elevator_private;
191 void *elevator_private2;
192
193 struct gendisk *rq_disk;
194 unsigned long start_time;
195
196 /* Number of scatter-gather DMA addr+len pairs after
197 * physical address coalescing is performed.
198 */
199 unsigned short nr_phys_segments;
200
201 unsigned short ioprio;
202
203 void *special;
204 char *buffer;
205
206 int tag;
207 int errors;
208
209 int ref_count;
210
211 /*
212 * when request is used as a packet command carrier
213 */
214 unsigned short cmd_len;
215 unsigned char __cmd[BLK_MAX_CDB];
216 unsigned char *cmd;
217
218 unsigned int data_len;
219 unsigned int extra_len; /* length of alignment and padding */
220 unsigned int sense_len;
221 void *data;
222 void *sense;
223
224 unsigned long deadline;
225 struct list_head timeout_list;
226 unsigned int timeout;
227 int retries;
228
229 /*
230 * completion callback.
231 */
232 rq_end_io_fn *end_io;
233 void *end_io_data;
234
235 /* for bidi */
236 struct request *next_rq;
237};
238
239static inline unsigned short req_get_ioprio(struct request *req)
240{
241 return req->ioprio;
242}
243
244/*
245 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
246 * requests. Some step values could eventually be made generic.
247 */
248struct request_pm_state
249{
250 /* PM state machine step value, currently driver specific */
251 int pm_step;
252 /* requested PM state value (S1, S2, S3, S4, ...) */
253 u32 pm_state;
254 void* data; /* for driver use */
255};
256
257#include <linux/elevator.h>
258
259typedef void (request_fn_proc) (struct request_queue *q);
260typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
261typedef int (prep_rq_fn) (struct request_queue *, struct request *);
262typedef void (unplug_fn) (struct request_queue *);
263typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
264
265struct bio_vec;
266struct bvec_merge_data {
267 struct block_device *bi_bdev;
268 sector_t bi_sector;
269 unsigned bi_size;
270 unsigned long bi_rw;
271};
272typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
273 struct bio_vec *);
274typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
275typedef void (softirq_done_fn)(struct request *);
276typedef int (dma_drain_needed_fn)(struct request *);
277typedef int (lld_busy_fn) (struct request_queue *q);
278
279enum blk_eh_timer_return {
280 BLK_EH_NOT_HANDLED,
281 BLK_EH_HANDLED,
282 BLK_EH_RESET_TIMER,
283};
284
285typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
286
287enum blk_queue_state {
288 Queue_down,
289 Queue_up,
290};
291
292struct blk_queue_tag {
293 struct request **tag_index; /* map of busy tags */
294 unsigned long *tag_map; /* bit map of free/busy tags */
295 int busy; /* current depth */
296 int max_depth; /* what we will send to device */
297 int real_max_depth; /* what the array can hold */
298 atomic_t refcnt; /* map can be shared */
299};
300
301#define BLK_SCSI_MAX_CMDS (256)
302#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
303
304struct blk_cmd_filter {
305 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
306 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
307 struct kobject kobj;
308};
309
310struct request_queue
311{
312 /*
313 * Together with queue_head for cacheline sharing
314 */
315 struct list_head queue_head;
316 struct request *last_merge;
317 struct elevator_queue *elevator;
318
319 /*
320 * the queue request freelist, one for reads and one for writes
321 */
322 struct request_list rq;
323
324 request_fn_proc *request_fn;
325 make_request_fn *make_request_fn;
326 prep_rq_fn *prep_rq_fn;
327 unplug_fn *unplug_fn;
328 prepare_discard_fn *prepare_discard_fn;
329 merge_bvec_fn *merge_bvec_fn;
330 prepare_flush_fn *prepare_flush_fn;
331 softirq_done_fn *softirq_done_fn;
332 rq_timed_out_fn *rq_timed_out_fn;
333 dma_drain_needed_fn *dma_drain_needed;
334 lld_busy_fn *lld_busy_fn;
335
336 /*
337 * Dispatch queue sorting
338 */
339 sector_t end_sector;
340 struct request *boundary_rq;
341
342 /*
343 * Auto-unplugging state
344 */
345 struct timer_list unplug_timer;
346 int unplug_thresh; /* After this many requests */
347 unsigned long unplug_delay; /* After this many jiffies */
348 struct work_struct unplug_work;
349
350 struct backing_dev_info backing_dev_info;
351
352 /*
353 * The queue owner gets to use this for whatever they like.
354 * ll_rw_blk doesn't touch it.
355 */
356 void *queuedata;
357
358 /*
359 * queue needs bounce pages for pages above this limit
360 */
361 unsigned long bounce_pfn;
362 gfp_t bounce_gfp;
363
364 /*
365 * various queue flags, see QUEUE_* below
366 */
367 unsigned long queue_flags;
368
369 /*
370 * protects queue structures from reentrancy. ->__queue_lock should
371 * _never_ be used directly, it is queue private. always use
372 * ->queue_lock.
373 */
374 spinlock_t __queue_lock;
375 spinlock_t *queue_lock;
376
377 /*
378 * queue kobject
379 */
380 struct kobject kobj;
381
382 /*
383 * queue settings
384 */
385 unsigned long nr_requests; /* Max # of requests */
386 unsigned int nr_congestion_on;
387 unsigned int nr_congestion_off;
388 unsigned int nr_batching;
389
390 unsigned int max_sectors;
391 unsigned int max_hw_sectors;
392 unsigned short max_phys_segments;
393 unsigned short max_hw_segments;
394 unsigned short hardsect_size;
395 unsigned int max_segment_size;
396
397 unsigned long seg_boundary_mask;
398 void *dma_drain_buffer;
399 unsigned int dma_drain_size;
400 unsigned int dma_pad_mask;
401 unsigned int dma_alignment;
402
403 struct blk_queue_tag *queue_tags;
404 struct list_head tag_busy_list;
405
406 unsigned int nr_sorted;
407 unsigned int in_flight;
408
409 unsigned int rq_timeout;
410 struct timer_list timeout;
411 struct list_head timeout_list;
412
413 /*
414 * sg stuff
415 */
416 unsigned int sg_timeout;
417 unsigned int sg_reserved_size;
418 int node;
419#ifdef CONFIG_BLK_DEV_IO_TRACE
420 struct blk_trace *blk_trace;
421#endif
422 /*
423 * reserved for flush operations
424 */
425 unsigned int ordered, next_ordered, ordseq;
426 int orderr, ordcolor;
427 struct request pre_flush_rq, bar_rq, post_flush_rq;
428 struct request *orig_bar_rq;
429
430 struct mutex sysfs_lock;
431
432#if defined(CONFIG_BLK_DEV_BSG)
433 struct bsg_class_device bsg_dev;
434#endif
435 struct blk_cmd_filter cmd_filter;
436};
437
438#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
439#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
440#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
441#define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
442#define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
443#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
444#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
445#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
446#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
447#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
448#define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
449#define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
450#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
451#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
452#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
453#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
454#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
455
456#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
457 (1 << QUEUE_FLAG_CLUSTER) | \
458 (1 << QUEUE_FLAG_STACKABLE))
459
460static inline int queue_is_locked(struct request_queue *q)
461{
462#ifdef CONFIG_SMP
463 spinlock_t *lock = q->queue_lock;
464 return lock && spin_is_locked(lock);
465#else
466 return 1;
467#endif
468}
469
470static inline void queue_flag_set_unlocked(unsigned int flag,
471 struct request_queue *q)
472{
473 __set_bit(flag, &q->queue_flags);
474}
475
476static inline int queue_flag_test_and_clear(unsigned int flag,
477 struct request_queue *q)
478{
479 WARN_ON_ONCE(!queue_is_locked(q));
480
481 if (test_bit(flag, &q->queue_flags)) {
482 __clear_bit(flag, &q->queue_flags);
483 return 1;
484 }
485
486 return 0;
487}
488
489static inline int queue_flag_test_and_set(unsigned int flag,
490 struct request_queue *q)
491{
492 WARN_ON_ONCE(!queue_is_locked(q));
493
494 if (!test_bit(flag, &q->queue_flags)) {
495 __set_bit(flag, &q->queue_flags);
496 return 0;
497 }
498
499 return 1;
500}
501
502static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
503{
504 WARN_ON_ONCE(!queue_is_locked(q));
505 __set_bit(flag, &q->queue_flags);
506}
507
508static inline void queue_flag_clear_unlocked(unsigned int flag,
509 struct request_queue *q)
510{
511 __clear_bit(flag, &q->queue_flags);
512}
513
514static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
515{
516 WARN_ON_ONCE(!queue_is_locked(q));
517 __clear_bit(flag, &q->queue_flags);
518}
519
520enum {
521 /*
522 * Hardbarrier is supported with one of the following methods.
523 *
524 * NONE : hardbarrier unsupported
525 * DRAIN : ordering by draining is enough
526 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
527 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
528 * TAG : ordering by tag is enough
529 * TAG_FLUSH : ordering by tag w/ pre and post flushes
530 * TAG_FUA : ordering by tag w/ pre flush and FUA write
531 */
532 QUEUE_ORDERED_BY_DRAIN = 0x01,
533 QUEUE_ORDERED_BY_TAG = 0x02,
534 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
535 QUEUE_ORDERED_DO_BAR = 0x20,
536 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
537 QUEUE_ORDERED_DO_FUA = 0x80,
538
539 QUEUE_ORDERED_NONE = 0x00,
540
541 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
542 QUEUE_ORDERED_DO_BAR,
543 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
544 QUEUE_ORDERED_DO_PREFLUSH |
545 QUEUE_ORDERED_DO_POSTFLUSH,
546 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
547 QUEUE_ORDERED_DO_PREFLUSH |
548 QUEUE_ORDERED_DO_FUA,
549
550 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
551 QUEUE_ORDERED_DO_BAR,
552 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
553 QUEUE_ORDERED_DO_PREFLUSH |
554 QUEUE_ORDERED_DO_POSTFLUSH,
555 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
556 QUEUE_ORDERED_DO_PREFLUSH |
557 QUEUE_ORDERED_DO_FUA,
558
559 /*
560 * Ordered operation sequence
561 */
562 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
563 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
564 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
565 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
566 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
567 QUEUE_ORDSEQ_DONE = 0x20,
568};
569
570#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
571#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
572#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
573#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
574#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
575#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
576#define blk_queue_flushing(q) ((q)->ordseq)
577#define blk_queue_stackable(q) \
578 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
579
580#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
581#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
582#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
583#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
584
585#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
586#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
587#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
588#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
589 blk_failfast_transport(rq) || \
590 blk_failfast_driver(rq))
591#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
592
593#define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
594
595#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
596#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
597#define blk_pm_request(rq) \
598 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
599
600#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
601#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
602#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
603#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
604#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
605#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
606/* rq->queuelist of dequeued request must be list_empty() */
607#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
608
609#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
610
611#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
612
613/*
614 * We regard a request as sync, if it's a READ or a SYNC write.
615 */
616#define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
617#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
618
619static inline int blk_queue_full(struct request_queue *q, int rw)
620{
621 if (rw == READ)
622 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
623 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
624}
625
626static inline void blk_set_queue_full(struct request_queue *q, int rw)
627{
628 if (rw == READ)
629 queue_flag_set(QUEUE_FLAG_READFULL, q);
630 else
631 queue_flag_set(QUEUE_FLAG_WRITEFULL, q);
632}
633
634static inline void blk_clear_queue_full(struct request_queue *q, int rw)
635{
636 if (rw == READ)
637 queue_flag_clear(QUEUE_FLAG_READFULL, q);
638 else
639 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q);
640}
641
642
643/*
644 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
645 * it already be started by driver.
646 */
647#define RQ_NOMERGE_FLAGS \
648 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
649#define rq_mergeable(rq) \
650 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
651 (blk_discard_rq(rq) || blk_fs_request((rq))))
652
653/*
654 * q->prep_rq_fn return values
655 */
656#define BLKPREP_OK 0 /* serve it */
657#define BLKPREP_KILL 1 /* fatal error, kill */
658#define BLKPREP_DEFER 2 /* leave on queue */
659
660extern unsigned long blk_max_low_pfn, blk_max_pfn;
661
662/*
663 * standard bounce addresses:
664 *
665 * BLK_BOUNCE_HIGH : bounce all highmem pages
666 * BLK_BOUNCE_ANY : don't bounce anything
667 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
668 */
669
670#if BITS_PER_LONG == 32
671#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
672#else
673#define BLK_BOUNCE_HIGH -1ULL
674#endif
675#define BLK_BOUNCE_ANY (-1ULL)
676#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
677
678/*
679 * default timeout for SG_IO if none specified
680 */
681#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
682#define BLK_MIN_SG_TIMEOUT (7 * HZ)
683
684#ifdef CONFIG_BOUNCE
685extern int init_emergency_isa_pool(void);
686extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
687#else
688static inline int init_emergency_isa_pool(void)
689{
690 return 0;
691}
692static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
693{
694}
695#endif /* CONFIG_MMU */
696
697struct rq_map_data {
698 struct page **pages;
699 int page_order;
700 int nr_entries;
701 unsigned long offset;
702 int null_mapped;
703};
704
705struct req_iterator {
706 int i;
707 struct bio *bio;
708};
709
710/* This should not be used directly - use rq_for_each_segment */
711#define for_each_bio(_bio) \
712 for (; _bio; _bio = _bio->bi_next)
713#define __rq_for_each_bio(_bio, rq) \
714 if ((rq->bio)) \
715 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
716
717#define rq_for_each_segment(bvl, _rq, _iter) \
718 __rq_for_each_bio(_iter.bio, _rq) \
719 bio_for_each_segment(bvl, _iter.bio, _iter.i)
720
721#define rq_iter_last(rq, _iter) \
722 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
723
724extern int blk_register_queue(struct gendisk *disk);
725extern void blk_unregister_queue(struct gendisk *disk);
726extern void register_disk(struct gendisk *dev);
727extern void generic_make_request(struct bio *bio);
728extern void blk_rq_init(struct request_queue *q, struct request *rq);
729extern void blk_put_request(struct request *);
730extern void __blk_put_request(struct request_queue *, struct request *);
731extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
732extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
733extern void blk_requeue_request(struct request_queue *, struct request *);
734extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
735extern int blk_lld_busy(struct request_queue *q);
736extern int blk_insert_cloned_request(struct request_queue *q,
737 struct request *rq);
738extern void blk_plug_device(struct request_queue *);
739extern void blk_plug_device_unlocked(struct request_queue *);
740extern int blk_remove_plug(struct request_queue *);
741extern void blk_recount_segments(struct request_queue *, struct bio *);
742extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
743 unsigned int, void __user *);
744extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
745 struct scsi_ioctl_command __user *);
746
747/*
748 * Temporary export, until SCSI gets fixed up.
749 */
750extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
751 struct bio *bio);
752
753/*
754 * A queue has just exitted congestion. Note this in the global counter of
755 * congested queues, and wake up anyone who was waiting for requests to be
756 * put back.
757 */
758static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
759{
760 clear_bdi_congested(&q->backing_dev_info, rw);
761}
762
763/*
764 * A queue has just entered congestion. Flag that in the queue's VM-visible
765 * state flags and increment the global gounter of congested queues.
766 */
767static inline void blk_set_queue_congested(struct request_queue *q, int rw)
768{
769 set_bdi_congested(&q->backing_dev_info, rw);
770}
771
772extern void blk_start_queue(struct request_queue *q);
773extern void blk_stop_queue(struct request_queue *q);
774extern void blk_sync_queue(struct request_queue *q);
775extern void __blk_stop_queue(struct request_queue *q);
776extern void __blk_run_queue(struct request_queue *);
777extern void blk_run_queue(struct request_queue *);
778extern void blk_start_queueing(struct request_queue *);
779extern int blk_rq_map_user(struct request_queue *, struct request *,
780 struct rq_map_data *, void __user *, unsigned long,
781 gfp_t);
782extern int blk_rq_unmap_user(struct bio *);
783extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
784extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
785 struct rq_map_data *, struct sg_iovec *, int,
786 unsigned int, gfp_t);
787extern int blk_execute_rq(struct request_queue *, struct gendisk *,
788 struct request *, int);
789extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
790 struct request *, int, rq_end_io_fn *);
791extern void blk_unplug(struct request_queue *q);
792
793static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
794{
795 return bdev->bd_disk->queue;
796}
797
798static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
799 struct page *page)
800{
801 if (bdi && bdi->unplug_io_fn)
802 bdi->unplug_io_fn(bdi, page);
803}
804
805static inline void blk_run_address_space(struct address_space *mapping)
806{
807 if (mapping)
808 blk_run_backing_dev(mapping->backing_dev_info, NULL);
809}
810
811extern void blkdev_dequeue_request(struct request *req);
812
813/*
814 * blk_end_request() and friends.
815 * __blk_end_request() and end_request() must be called with
816 * the request queue spinlock acquired.
817 *
818 * Several drivers define their own end_request and call
819 * blk_end_request() for parts of the original function.
820 * This prevents code duplication in drivers.
821 */
822extern int blk_end_request(struct request *rq, int error,
823 unsigned int nr_bytes);
824extern int __blk_end_request(struct request *rq, int error,
825 unsigned int nr_bytes);
826extern int blk_end_bidi_request(struct request *rq, int error,
827 unsigned int nr_bytes, unsigned int bidi_bytes);
828extern void end_request(struct request *, int);
829extern int blk_end_request_callback(struct request *rq, int error,
830 unsigned int nr_bytes,
831 int (drv_callback)(struct request *));
832extern void blk_complete_request(struct request *);
833extern void __blk_complete_request(struct request *);
834extern void blk_abort_request(struct request *);
835extern void blk_abort_queue(struct request_queue *);
836extern void blk_update_request(struct request *rq, int error,
837 unsigned int nr_bytes);
838
839/*
840 * blk_end_request() takes bytes instead of sectors as a complete size.
841 * blk_rq_bytes() returns bytes left to complete in the entire request.
842 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
843 */
844extern unsigned int blk_rq_bytes(struct request *rq);
845extern unsigned int blk_rq_cur_bytes(struct request *rq);
846
847/*
848 * Access functions for manipulating queue properties
849 */
850extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
851 spinlock_t *lock, int node_id);
852extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
853extern void blk_cleanup_queue(struct request_queue *);
854extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
855extern void blk_queue_bounce_limit(struct request_queue *, u64);
856extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
857extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
858extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
859extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
860extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
861extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
862extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
863extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
864extern int blk_queue_dma_drain(struct request_queue *q,
865 dma_drain_needed_fn *dma_drain_needed,
866 void *buf, unsigned int size);
867extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
868extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
869extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
870extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
871extern void blk_queue_dma_alignment(struct request_queue *, int);
872extern void blk_queue_update_dma_alignment(struct request_queue *, int);
873extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
874extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
875extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
876extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
877extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
878extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
879extern bool blk_do_ordered(struct request_queue *, struct request **);
880extern unsigned blk_ordered_cur_seq(struct request_queue *);
881extern unsigned blk_ordered_req_seq(struct request *);
882extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
883
884extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
885extern void blk_dump_rq_flags(struct request *, char *);
886extern void generic_unplug_device(struct request_queue *);
887extern long nr_blockdev_pages(void);
888
889int blk_get_queue(struct request_queue *);
890struct request_queue *blk_alloc_queue(gfp_t);
891struct request_queue *blk_alloc_queue_node(gfp_t, int);
892extern void blk_put_queue(struct request_queue *);
893
894/*
895 * tag stuff
896 */
897#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
898extern int blk_queue_start_tag(struct request_queue *, struct request *);
899extern struct request *blk_queue_find_tag(struct request_queue *, int);
900extern void blk_queue_end_tag(struct request_queue *, struct request *);
901extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
902extern void blk_queue_free_tags(struct request_queue *);
903extern int blk_queue_resize_tags(struct request_queue *, int);
904extern void blk_queue_invalidate_tags(struct request_queue *);
905extern struct blk_queue_tag *blk_init_tags(int);
906extern void blk_free_tags(struct blk_queue_tag *);
907
908static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
909 int tag)
910{
911 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
912 return NULL;
913 return bqt->tag_index[tag];
914}
915
916extern int blkdev_issue_flush(struct block_device *, sector_t *);
917extern int blkdev_issue_discard(struct block_device *,
918 sector_t sector, sector_t nr_sects, gfp_t);
919
920static inline int sb_issue_discard(struct super_block *sb,
921 sector_t block, sector_t nr_blocks)
922{
923 block <<= (sb->s_blocksize_bits - 9);
924 nr_blocks <<= (sb->s_blocksize_bits - 9);
925 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
926}
927
928/*
929* command filter functions
930*/
931extern int blk_verify_command(struct blk_cmd_filter *filter,
932 unsigned char *cmd, fmode_t has_write_perm);
933extern void blk_unregister_filter(struct gendisk *disk);
934extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
935
936#define MAX_PHYS_SEGMENTS 128
937#define MAX_HW_SEGMENTS 128
938#define SAFE_MAX_SECTORS 255
939#define BLK_DEF_MAX_SECTORS 1024
940
941#define MAX_SEGMENT_SIZE 65536
942
943#define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
944
945#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
946
947static inline int queue_hardsect_size(struct request_queue *q)
948{
949 int retval = 512;
950
951 if (q && q->hardsect_size)
952 retval = q->hardsect_size;
953
954 return retval;
955}
956
957static inline int bdev_hardsect_size(struct block_device *bdev)
958{
959 return queue_hardsect_size(bdev_get_queue(bdev));
960}
961
962static inline int queue_dma_alignment(struct request_queue *q)
963{
964 return q ? q->dma_alignment : 511;
965}
966
967static inline int blk_rq_aligned(struct request_queue *q, void *addr,
968 unsigned int len)
969{
970 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
971 return !((unsigned long)addr & alignment) && !(len & alignment);
972}
973
974/* assumes size > 256 */
975static inline unsigned int blksize_bits(unsigned int size)
976{
977 unsigned int bits = 8;
978 do {
979 bits++;
980 size >>= 1;
981 } while (size > 256);
982 return bits;
983}
984
985static inline unsigned int block_size(struct block_device *bdev)
986{
987 return bdev->bd_block_size;
988}
989
990typedef struct {struct page *v;} Sector;
991
992unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
993
994static inline void put_dev_sector(Sector p)
995{
996 page_cache_release(p.v);
997}
998
999struct work_struct;
1000int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1001
1002#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1003 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1004#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1005 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1006
1007#if defined(CONFIG_BLK_DEV_INTEGRITY)
1008
1009#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1010#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1011
1012struct blk_integrity_exchg {
1013 void *prot_buf;
1014 void *data_buf;
1015 sector_t sector;
1016 unsigned int data_size;
1017 unsigned short sector_size;
1018 const char *disk_name;
1019};
1020
1021typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1022typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1023typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1024typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1025
1026struct blk_integrity {
1027 integrity_gen_fn *generate_fn;
1028 integrity_vrfy_fn *verify_fn;
1029 integrity_set_tag_fn *set_tag_fn;
1030 integrity_get_tag_fn *get_tag_fn;
1031
1032 unsigned short flags;
1033 unsigned short tuple_size;
1034 unsigned short sector_size;
1035 unsigned short tag_size;
1036
1037 const char *name;
1038
1039 struct kobject kobj;
1040};
1041
1042extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1043extern void blk_integrity_unregister(struct gendisk *);
1044extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1045extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1046extern int blk_rq_count_integrity_sg(struct request *);
1047
1048static inline
1049struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1050{
1051 return bdev->bd_disk->integrity;
1052}
1053
1054static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1055{
1056 return disk->integrity;
1057}
1058
1059static inline int blk_integrity_rq(struct request *rq)
1060{
1061 if (rq->bio == NULL)
1062 return 0;
1063
1064 return bio_integrity(rq->bio);
1065}
1066
1067#else /* CONFIG_BLK_DEV_INTEGRITY */
1068
1069#define blk_integrity_rq(rq) (0)
1070#define blk_rq_count_integrity_sg(a) (0)
1071#define blk_rq_map_integrity_sg(a, b) (0)
1072#define bdev_get_integrity(a) (0)
1073#define blk_get_integrity(a) (0)
1074#define blk_integrity_compare(a, b) (0)
1075#define blk_integrity_register(a, b) (0)
1076#define blk_integrity_unregister(a) do { } while (0);
1077
1078#endif /* CONFIG_BLK_DEV_INTEGRITY */
1079
1080struct block_device_operations {
1081 int (*open) (struct block_device *, fmode_t);
1082 int (*release) (struct gendisk *, fmode_t);
1083 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1084 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1085 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1086 int (*direct_access) (struct block_device *, sector_t,
1087 void **, unsigned long *);
1088 int (*media_changed) (struct gendisk *);
1089 int (*revalidate_disk) (struct gendisk *);
1090 int (*getgeo)(struct block_device *, struct hd_geometry *);
1091 struct module *owner;
1092};
1093
1094extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1095 unsigned long);
1096#else /* CONFIG_BLOCK */
1097/*
1098 * stubs for when the block layer is configured out
1099 */
1100#define buffer_heads_over_limit 0
1101
1102static inline long nr_blockdev_pages(void)
1103{
1104 return 0;
1105}
1106
1107#endif /* CONFIG_BLOCK */
1108
1109#endif
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