projects/linux·blob v3.13 · refs

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1#ifndef _LINUX_BLKDEV_H
2#define _LINUX_BLKDEV_H
3
4#include <linux/sched.h>
5
6#ifdef CONFIG_BLOCK
7
8#include <linux/major.h>
9#include <linux/genhd.h>
10#include <linux/list.h>
11#include <linux/llist.h>
12#include <linux/timer.h>
13#include <linux/workqueue.h>
14#include <linux/pagemap.h>
15#include <linux/backing-dev.h>
16#include <linux/wait.h>
17#include <linux/mempool.h>
18#include <linux/bio.h>
19#include <linux/stringify.h>
20#include <linux/gfp.h>
21#include <linux/bsg.h>
22#include <linux/smp.h>
23#include <linux/rcupdate.h>
24
25#include <asm/scatterlist.h>
26
27struct module;
28struct scsi_ioctl_command;
29
30struct request_queue;
31struct elevator_queue;
32struct request_pm_state;
33struct blk_trace;
34struct request;
35struct sg_io_hdr;
36struct bsg_job;
37struct blkcg_gq;
38
39#define BLKDEV_MIN_RQ 4
40#define BLKDEV_MAX_RQ 128 /* Default maximum */
41
42/*
43 * Maximum number of blkcg policies allowed to be registered concurrently.
44 * Defined here to simplify include dependency.
45 */
46#define BLKCG_MAX_POLS 2
47
48struct request;
49typedef void (rq_end_io_fn)(struct request *, int);
50
51#define BLK_RL_SYNCFULL (1U << 0)
52#define BLK_RL_ASYNCFULL (1U << 1)
53
54struct request_list {
55 struct request_queue *q; /* the queue this rl belongs to */
56#ifdef CONFIG_BLK_CGROUP
57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */
58#endif
59 /*
60 * count[], starved[], and wait[] are indexed by
61 * BLK_RW_SYNC/BLK_RW_ASYNC
62 */
63 int count[2];
64 int starved[2];
65 mempool_t *rq_pool;
66 wait_queue_head_t wait[2];
67 unsigned int flags;
68};
69
70/*
71 * request command types
72 */
73enum rq_cmd_type_bits {
74 REQ_TYPE_FS = 1, /* fs request */
75 REQ_TYPE_BLOCK_PC, /* scsi command */
76 REQ_TYPE_SENSE, /* sense request */
77 REQ_TYPE_PM_SUSPEND, /* suspend request */
78 REQ_TYPE_PM_RESUME, /* resume request */
79 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
80 REQ_TYPE_SPECIAL, /* driver defined type */
81 /*
82 * for ATA/ATAPI devices. this really doesn't belong here, ide should
83 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
84 * private REQ_LB opcodes to differentiate what type of request this is
85 */
86 REQ_TYPE_ATA_TASKFILE,
87 REQ_TYPE_ATA_PC,
88};
89
90#define BLK_MAX_CDB 16
91
92/*
93 * try to put the fields that are referenced together in the same cacheline.
94 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
95 * as well!
96 */
97struct request {
98 union {
99 struct list_head queuelist;
100 struct llist_node ll_list;
101 };
102 union {
103 struct call_single_data csd;
104 struct work_struct mq_flush_data;
105 };
106
107 struct request_queue *q;
108 struct blk_mq_ctx *mq_ctx;
109
110 u64 cmd_flags;
111 enum rq_cmd_type_bits cmd_type;
112 unsigned long atomic_flags;
113
114 int cpu;
115
116 /* the following two fields are internal, NEVER access directly */
117 unsigned int __data_len; /* total data len */
118 sector_t __sector; /* sector cursor */
119
120 struct bio *bio;
121 struct bio *biotail;
122
123 struct hlist_node hash; /* merge hash */
124 /*
125 * The rb_node is only used inside the io scheduler, requests
126 * are pruned when moved to the dispatch queue. So let the
127 * completion_data share space with the rb_node.
128 */
129 union {
130 struct rb_node rb_node; /* sort/lookup */
131 void *completion_data;
132 };
133
134 /*
135 * Three pointers are available for the IO schedulers, if they need
136 * more they have to dynamically allocate it. Flush requests are
137 * never put on the IO scheduler. So let the flush fields share
138 * space with the elevator data.
139 */
140 union {
141 struct {
142 struct io_cq *icq;
143 void *priv[2];
144 } elv;
145
146 struct {
147 unsigned int seq;
148 struct list_head list;
149 rq_end_io_fn *saved_end_io;
150 } flush;
151 };
152
153 struct gendisk *rq_disk;
154 struct hd_struct *part;
155 unsigned long start_time;
156#ifdef CONFIG_BLK_CGROUP
157 struct request_list *rl; /* rl this rq is alloced from */
158 unsigned long long start_time_ns;
159 unsigned long long io_start_time_ns; /* when passed to hardware */
160#endif
161 /* Number of scatter-gather DMA addr+len pairs after
162 * physical address coalescing is performed.
163 */
164 unsigned short nr_phys_segments;
165#if defined(CONFIG_BLK_DEV_INTEGRITY)
166 unsigned short nr_integrity_segments;
167#endif
168
169 unsigned short ioprio;
170
171 void *special; /* opaque pointer available for LLD use */
172 char *buffer; /* kaddr of the current segment if available */
173
174 int tag;
175 int errors;
176
177 /*
178 * when request is used as a packet command carrier
179 */
180 unsigned char __cmd[BLK_MAX_CDB];
181 unsigned char *cmd;
182 unsigned short cmd_len;
183
184 unsigned int extra_len; /* length of alignment and padding */
185 unsigned int sense_len;
186 unsigned int resid_len; /* residual count */
187 void *sense;
188
189 unsigned long deadline;
190 struct list_head timeout_list;
191 unsigned int timeout;
192 int retries;
193
194 /*
195 * completion callback.
196 */
197 rq_end_io_fn *end_io;
198 void *end_io_data;
199
200 /* for bidi */
201 struct request *next_rq;
202};
203
204static inline unsigned short req_get_ioprio(struct request *req)
205{
206 return req->ioprio;
207}
208
209/*
210 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
211 * requests. Some step values could eventually be made generic.
212 */
213struct request_pm_state
214{
215 /* PM state machine step value, currently driver specific */
216 int pm_step;
217 /* requested PM state value (S1, S2, S3, S4, ...) */
218 u32 pm_state;
219 void* data; /* for driver use */
220};
221
222#include <linux/elevator.h>
223
224struct blk_queue_ctx;
225
226typedef void (request_fn_proc) (struct request_queue *q);
227typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
228typedef int (prep_rq_fn) (struct request_queue *, struct request *);
229typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
230
231struct bio_vec;
232struct bvec_merge_data {
233 struct block_device *bi_bdev;
234 sector_t bi_sector;
235 unsigned bi_size;
236 unsigned long bi_rw;
237};
238typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
239 struct bio_vec *);
240typedef void (softirq_done_fn)(struct request *);
241typedef int (dma_drain_needed_fn)(struct request *);
242typedef int (lld_busy_fn) (struct request_queue *q);
243typedef int (bsg_job_fn) (struct bsg_job *);
244
245enum blk_eh_timer_return {
246 BLK_EH_NOT_HANDLED,
247 BLK_EH_HANDLED,
248 BLK_EH_RESET_TIMER,
249};
250
251typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
252
253enum blk_queue_state {
254 Queue_down,
255 Queue_up,
256};
257
258struct blk_queue_tag {
259 struct request **tag_index; /* map of busy tags */
260 unsigned long *tag_map; /* bit map of free/busy tags */
261 int busy; /* current depth */
262 int max_depth; /* what we will send to device */
263 int real_max_depth; /* what the array can hold */
264 atomic_t refcnt; /* map can be shared */
265};
266
267#define BLK_SCSI_MAX_CMDS (256)
268#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
269
270struct queue_limits {
271 unsigned long bounce_pfn;
272 unsigned long seg_boundary_mask;
273
274 unsigned int max_hw_sectors;
275 unsigned int max_sectors;
276 unsigned int max_segment_size;
277 unsigned int physical_block_size;
278 unsigned int alignment_offset;
279 unsigned int io_min;
280 unsigned int io_opt;
281 unsigned int max_discard_sectors;
282 unsigned int max_write_same_sectors;
283 unsigned int discard_granularity;
284 unsigned int discard_alignment;
285
286 unsigned short logical_block_size;
287 unsigned short max_segments;
288 unsigned short max_integrity_segments;
289
290 unsigned char misaligned;
291 unsigned char discard_misaligned;
292 unsigned char cluster;
293 unsigned char discard_zeroes_data;
294};
295
296struct request_queue {
297 /*
298 * Together with queue_head for cacheline sharing
299 */
300 struct list_head queue_head;
301 struct request *last_merge;
302 struct elevator_queue *elevator;
303 int nr_rqs[2]; /* # allocated [a]sync rqs */
304 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
305
306 /*
307 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
308 * is used, root blkg allocates from @q->root_rl and all other
309 * blkgs from their own blkg->rl. Which one to use should be
310 * determined using bio_request_list().
311 */
312 struct request_list root_rl;
313
314 request_fn_proc *request_fn;
315 make_request_fn *make_request_fn;
316 prep_rq_fn *prep_rq_fn;
317 unprep_rq_fn *unprep_rq_fn;
318 merge_bvec_fn *merge_bvec_fn;
319 softirq_done_fn *softirq_done_fn;
320 rq_timed_out_fn *rq_timed_out_fn;
321 dma_drain_needed_fn *dma_drain_needed;
322 lld_busy_fn *lld_busy_fn;
323
324 struct blk_mq_ops *mq_ops;
325
326 unsigned int *mq_map;
327
328 /* sw queues */
329 struct blk_mq_ctx *queue_ctx;
330 unsigned int nr_queues;
331
332 /* hw dispatch queues */
333 struct blk_mq_hw_ctx **queue_hw_ctx;
334 unsigned int nr_hw_queues;
335
336 /*
337 * Dispatch queue sorting
338 */
339 sector_t end_sector;
340 struct request *boundary_rq;
341
342 /*
343 * Delayed queue handling
344 */
345 struct delayed_work delay_work;
346
347 struct backing_dev_info backing_dev_info;
348
349 /*
350 * The queue owner gets to use this for whatever they like.
351 * ll_rw_blk doesn't touch it.
352 */
353 void *queuedata;
354
355 /*
356 * various queue flags, see QUEUE_* below
357 */
358 unsigned long queue_flags;
359
360 /*
361 * ida allocated id for this queue. Used to index queues from
362 * ioctx.
363 */
364 int id;
365
366 /*
367 * queue needs bounce pages for pages above this limit
368 */
369 gfp_t bounce_gfp;
370
371 /*
372 * protects queue structures from reentrancy. ->__queue_lock should
373 * _never_ be used directly, it is queue private. always use
374 * ->queue_lock.
375 */
376 spinlock_t __queue_lock;
377 spinlock_t *queue_lock;
378
379 /*
380 * queue kobject
381 */
382 struct kobject kobj;
383
384 /*
385 * mq queue kobject
386 */
387 struct kobject mq_kobj;
388
389#ifdef CONFIG_PM_RUNTIME
390 struct device *dev;
391 int rpm_status;
392 unsigned int nr_pending;
393#endif
394
395 /*
396 * queue settings
397 */
398 unsigned long nr_requests; /* Max # of requests */
399 unsigned int nr_congestion_on;
400 unsigned int nr_congestion_off;
401 unsigned int nr_batching;
402
403 unsigned int dma_drain_size;
404 void *dma_drain_buffer;
405 unsigned int dma_pad_mask;
406 unsigned int dma_alignment;
407
408 struct blk_queue_tag *queue_tags;
409 struct list_head tag_busy_list;
410
411 unsigned int nr_sorted;
412 unsigned int in_flight[2];
413 /*
414 * Number of active block driver functions for which blk_drain_queue()
415 * must wait. Must be incremented around functions that unlock the
416 * queue_lock internally, e.g. scsi_request_fn().
417 */
418 unsigned int request_fn_active;
419
420 unsigned int rq_timeout;
421 struct timer_list timeout;
422 struct list_head timeout_list;
423
424 struct list_head icq_list;
425#ifdef CONFIG_BLK_CGROUP
426 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
427 struct blkcg_gq *root_blkg;
428 struct list_head blkg_list;
429#endif
430
431 struct queue_limits limits;
432
433 /*
434 * sg stuff
435 */
436 unsigned int sg_timeout;
437 unsigned int sg_reserved_size;
438 int node;
439#ifdef CONFIG_BLK_DEV_IO_TRACE
440 struct blk_trace *blk_trace;
441#endif
442 /*
443 * for flush operations
444 */
445 unsigned int flush_flags;
446 unsigned int flush_not_queueable:1;
447 unsigned int flush_queue_delayed:1;
448 unsigned int flush_pending_idx:1;
449 unsigned int flush_running_idx:1;
450 unsigned long flush_pending_since;
451 struct list_head flush_queue[2];
452 struct list_head flush_data_in_flight;
453 union {
454 struct request flush_rq;
455 struct {
456 spinlock_t mq_flush_lock;
457 struct work_struct mq_flush_work;
458 };
459 };
460
461 struct mutex sysfs_lock;
462
463 int bypass_depth;
464
465#if defined(CONFIG_BLK_DEV_BSG)
466 bsg_job_fn *bsg_job_fn;
467 int bsg_job_size;
468 struct bsg_class_device bsg_dev;
469#endif
470
471#ifdef CONFIG_BLK_DEV_THROTTLING
472 /* Throttle data */
473 struct throtl_data *td;
474#endif
475 struct rcu_head rcu_head;
476 wait_queue_head_t mq_freeze_wq;
477 struct percpu_counter mq_usage_counter;
478 struct list_head all_q_node;
479};
480
481#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
482#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
483#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
484#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
485#define QUEUE_FLAG_DYING 5 /* queue being torn down */
486#define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
487#define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
488#define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
489#define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
490#define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
491#define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
492#define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
493#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
494#define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
495#define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
496#define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
497#define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
498#define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
499#define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
500#define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
501#define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
502
503#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
504 (1 << QUEUE_FLAG_STACKABLE) | \
505 (1 << QUEUE_FLAG_SAME_COMP) | \
506 (1 << QUEUE_FLAG_ADD_RANDOM))
507
508#define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
509 (1 << QUEUE_FLAG_SAME_COMP))
510
511static inline void queue_lockdep_assert_held(struct request_queue *q)
512{
513 if (q->queue_lock)
514 lockdep_assert_held(q->queue_lock);
515}
516
517static inline void queue_flag_set_unlocked(unsigned int flag,
518 struct request_queue *q)
519{
520 __set_bit(flag, &q->queue_flags);
521}
522
523static inline int queue_flag_test_and_clear(unsigned int flag,
524 struct request_queue *q)
525{
526 queue_lockdep_assert_held(q);
527
528 if (test_bit(flag, &q->queue_flags)) {
529 __clear_bit(flag, &q->queue_flags);
530 return 1;
531 }
532
533 return 0;
534}
535
536static inline int queue_flag_test_and_set(unsigned int flag,
537 struct request_queue *q)
538{
539 queue_lockdep_assert_held(q);
540
541 if (!test_bit(flag, &q->queue_flags)) {
542 __set_bit(flag, &q->queue_flags);
543 return 0;
544 }
545
546 return 1;
547}
548
549static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
550{
551 queue_lockdep_assert_held(q);
552 __set_bit(flag, &q->queue_flags);
553}
554
555static inline void queue_flag_clear_unlocked(unsigned int flag,
556 struct request_queue *q)
557{
558 __clear_bit(flag, &q->queue_flags);
559}
560
561static inline int queue_in_flight(struct request_queue *q)
562{
563 return q->in_flight[0] + q->in_flight[1];
564}
565
566static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
567{
568 queue_lockdep_assert_held(q);
569 __clear_bit(flag, &q->queue_flags);
570}
571
572#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
573#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
574#define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
575#define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
576#define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
577#define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
578#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
579#define blk_queue_noxmerges(q) \
580 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
581#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
582#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
583#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
584#define blk_queue_stackable(q) \
585 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
586#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
587#define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
588 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
589
590#define blk_noretry_request(rq) \
591 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
592 REQ_FAILFAST_DRIVER))
593
594#define blk_account_rq(rq) \
595 (((rq)->cmd_flags & REQ_STARTED) && \
596 ((rq)->cmd_type == REQ_TYPE_FS))
597
598#define blk_pm_request(rq) \
599 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
600 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
601
602#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
603#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
604/* rq->queuelist of dequeued request must be list_empty() */
605#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
606
607#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
608
609#define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
610
611static inline unsigned int blk_queue_cluster(struct request_queue *q)
612{
613 return q->limits.cluster;
614}
615
616/*
617 * We regard a request as sync, if either a read or a sync write
618 */
619static inline bool rw_is_sync(unsigned int rw_flags)
620{
621 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
622}
623
624static inline bool rq_is_sync(struct request *rq)
625{
626 return rw_is_sync(rq->cmd_flags);
627}
628
629static inline bool blk_rl_full(struct request_list *rl, bool sync)
630{
631 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
632
633 return rl->flags & flag;
634}
635
636static inline void blk_set_rl_full(struct request_list *rl, bool sync)
637{
638 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
639
640 rl->flags |= flag;
641}
642
643static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
644{
645 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
646
647 rl->flags &= ~flag;
648}
649
650static inline bool rq_mergeable(struct request *rq)
651{
652 if (rq->cmd_type != REQ_TYPE_FS)
653 return false;
654
655 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
656 return false;
657
658 return true;
659}
660
661static inline bool blk_check_merge_flags(unsigned int flags1,
662 unsigned int flags2)
663{
664 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
665 return false;
666
667 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
668 return false;
669
670 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
671 return false;
672
673 return true;
674}
675
676static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
677{
678 if (bio_data(a) == bio_data(b))
679 return true;
680
681 return false;
682}
683
684/*
685 * q->prep_rq_fn return values
686 */
687#define BLKPREP_OK 0 /* serve it */
688#define BLKPREP_KILL 1 /* fatal error, kill */
689#define BLKPREP_DEFER 2 /* leave on queue */
690
691extern unsigned long blk_max_low_pfn, blk_max_pfn;
692
693/*
694 * standard bounce addresses:
695 *
696 * BLK_BOUNCE_HIGH : bounce all highmem pages
697 * BLK_BOUNCE_ANY : don't bounce anything
698 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
699 */
700
701#if BITS_PER_LONG == 32
702#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
703#else
704#define BLK_BOUNCE_HIGH -1ULL
705#endif
706#define BLK_BOUNCE_ANY (-1ULL)
707#define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
708
709/*
710 * default timeout for SG_IO if none specified
711 */
712#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
713#define BLK_MIN_SG_TIMEOUT (7 * HZ)
714
715#ifdef CONFIG_BOUNCE
716extern int init_emergency_isa_pool(void);
717extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
718#else
719static inline int init_emergency_isa_pool(void)
720{
721 return 0;
722}
723static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
724{
725}
726#endif /* CONFIG_MMU */
727
728struct rq_map_data {
729 struct page **pages;
730 int page_order;
731 int nr_entries;
732 unsigned long offset;
733 int null_mapped;
734 int from_user;
735};
736
737struct req_iterator {
738 int i;
739 struct bio *bio;
740};
741
742/* This should not be used directly - use rq_for_each_segment */
743#define for_each_bio(_bio) \
744 for (; _bio; _bio = _bio->bi_next)
745#define __rq_for_each_bio(_bio, rq) \
746 if ((rq->bio)) \
747 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
748
749#define rq_for_each_segment(bvl, _rq, _iter) \
750 __rq_for_each_bio(_iter.bio, _rq) \
751 bio_for_each_segment(bvl, _iter.bio, _iter.i)
752
753#define rq_iter_last(rq, _iter) \
754 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
755
756#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
757# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
758#endif
759#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
760extern void rq_flush_dcache_pages(struct request *rq);
761#else
762static inline void rq_flush_dcache_pages(struct request *rq)
763{
764}
765#endif
766
767extern int blk_register_queue(struct gendisk *disk);
768extern void blk_unregister_queue(struct gendisk *disk);
769extern void generic_make_request(struct bio *bio);
770extern void blk_rq_init(struct request_queue *q, struct request *rq);
771extern void blk_put_request(struct request *);
772extern void __blk_put_request(struct request_queue *, struct request *);
773extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
774extern struct request *blk_make_request(struct request_queue *, struct bio *,
775 gfp_t);
776extern void blk_requeue_request(struct request_queue *, struct request *);
777extern void blk_add_request_payload(struct request *rq, struct page *page,
778 unsigned int len);
779extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
780extern int blk_lld_busy(struct request_queue *q);
781extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
782 struct bio_set *bs, gfp_t gfp_mask,
783 int (*bio_ctr)(struct bio *, struct bio *, void *),
784 void *data);
785extern void blk_rq_unprep_clone(struct request *rq);
786extern int blk_insert_cloned_request(struct request_queue *q,
787 struct request *rq);
788extern void blk_delay_queue(struct request_queue *, unsigned long);
789extern void blk_recount_segments(struct request_queue *, struct bio *);
790extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
791extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
792 unsigned int, void __user *);
793extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
794 unsigned int, void __user *);
795extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
796 struct scsi_ioctl_command __user *);
797
798extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
799
800/*
801 * A queue has just exitted congestion. Note this in the global counter of
802 * congested queues, and wake up anyone who was waiting for requests to be
803 * put back.
804 */
805static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
806{
807 clear_bdi_congested(&q->backing_dev_info, sync);
808}
809
810/*
811 * A queue has just entered congestion. Flag that in the queue's VM-visible
812 * state flags and increment the global gounter of congested queues.
813 */
814static inline void blk_set_queue_congested(struct request_queue *q, int sync)
815{
816 set_bdi_congested(&q->backing_dev_info, sync);
817}
818
819extern void blk_start_queue(struct request_queue *q);
820extern void blk_stop_queue(struct request_queue *q);
821extern void blk_sync_queue(struct request_queue *q);
822extern void __blk_stop_queue(struct request_queue *q);
823extern void __blk_run_queue(struct request_queue *q);
824extern void blk_run_queue(struct request_queue *);
825extern void blk_run_queue_async(struct request_queue *q);
826extern int blk_rq_map_user(struct request_queue *, struct request *,
827 struct rq_map_data *, void __user *, unsigned long,
828 gfp_t);
829extern int blk_rq_unmap_user(struct bio *);
830extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
831extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
832 struct rq_map_data *, struct sg_iovec *, int,
833 unsigned int, gfp_t);
834extern int blk_execute_rq(struct request_queue *, struct gendisk *,
835 struct request *, int);
836extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
837 struct request *, int, rq_end_io_fn *);
838
839static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
840{
841 return bdev->bd_disk->queue;
842}
843
844/*
845 * blk_rq_pos() : the current sector
846 * blk_rq_bytes() : bytes left in the entire request
847 * blk_rq_cur_bytes() : bytes left in the current segment
848 * blk_rq_err_bytes() : bytes left till the next error boundary
849 * blk_rq_sectors() : sectors left in the entire request
850 * blk_rq_cur_sectors() : sectors left in the current segment
851 */
852static inline sector_t blk_rq_pos(const struct request *rq)
853{
854 return rq->__sector;
855}
856
857static inline unsigned int blk_rq_bytes(const struct request *rq)
858{
859 return rq->__data_len;
860}
861
862static inline int blk_rq_cur_bytes(const struct request *rq)
863{
864 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
865}
866
867extern unsigned int blk_rq_err_bytes(const struct request *rq);
868
869static inline unsigned int blk_rq_sectors(const struct request *rq)
870{
871 return blk_rq_bytes(rq) >> 9;
872}
873
874static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
875{
876 return blk_rq_cur_bytes(rq) >> 9;
877}
878
879static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
880 unsigned int cmd_flags)
881{
882 if (unlikely(cmd_flags & REQ_DISCARD))
883 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
884
885 if (unlikely(cmd_flags & REQ_WRITE_SAME))
886 return q->limits.max_write_same_sectors;
887
888 return q->limits.max_sectors;
889}
890
891static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
892{
893 struct request_queue *q = rq->q;
894
895 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
896 return q->limits.max_hw_sectors;
897
898 return blk_queue_get_max_sectors(q, rq->cmd_flags);
899}
900
901static inline unsigned int blk_rq_count_bios(struct request *rq)
902{
903 unsigned int nr_bios = 0;
904 struct bio *bio;
905
906 __rq_for_each_bio(bio, rq)
907 nr_bios++;
908
909 return nr_bios;
910}
911
912/*
913 * Request issue related functions.
914 */
915extern struct request *blk_peek_request(struct request_queue *q);
916extern void blk_start_request(struct request *rq);
917extern struct request *blk_fetch_request(struct request_queue *q);
918
919/*
920 * Request completion related functions.
921 *
922 * blk_update_request() completes given number of bytes and updates
923 * the request without completing it.
924 *
925 * blk_end_request() and friends. __blk_end_request() must be called
926 * with the request queue spinlock acquired.
927 *
928 * Several drivers define their own end_request and call
929 * blk_end_request() for parts of the original function.
930 * This prevents code duplication in drivers.
931 */
932extern bool blk_update_request(struct request *rq, int error,
933 unsigned int nr_bytes);
934extern bool blk_end_request(struct request *rq, int error,
935 unsigned int nr_bytes);
936extern void blk_end_request_all(struct request *rq, int error);
937extern bool blk_end_request_cur(struct request *rq, int error);
938extern bool blk_end_request_err(struct request *rq, int error);
939extern bool __blk_end_request(struct request *rq, int error,
940 unsigned int nr_bytes);
941extern void __blk_end_request_all(struct request *rq, int error);
942extern bool __blk_end_request_cur(struct request *rq, int error);
943extern bool __blk_end_request_err(struct request *rq, int error);
944
945extern void blk_complete_request(struct request *);
946extern void __blk_complete_request(struct request *);
947extern void blk_abort_request(struct request *);
948extern void blk_unprep_request(struct request *);
949
950/*
951 * Access functions for manipulating queue properties
952 */
953extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
954 spinlock_t *lock, int node_id);
955extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
956extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
957 request_fn_proc *, spinlock_t *);
958extern void blk_cleanup_queue(struct request_queue *);
959extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
960extern void blk_queue_bounce_limit(struct request_queue *, u64);
961extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
962extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
963extern void blk_queue_max_segments(struct request_queue *, unsigned short);
964extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
965extern void blk_queue_max_discard_sectors(struct request_queue *q,
966 unsigned int max_discard_sectors);
967extern void blk_queue_max_write_same_sectors(struct request_queue *q,
968 unsigned int max_write_same_sectors);
969extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
970extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
971extern void blk_queue_alignment_offset(struct request_queue *q,
972 unsigned int alignment);
973extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
974extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
975extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
976extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
977extern void blk_set_default_limits(struct queue_limits *lim);
978extern void blk_set_stacking_limits(struct queue_limits *lim);
979extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
980 sector_t offset);
981extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
982 sector_t offset);
983extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
984 sector_t offset);
985extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
986extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
987extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
988extern int blk_queue_dma_drain(struct request_queue *q,
989 dma_drain_needed_fn *dma_drain_needed,
990 void *buf, unsigned int size);
991extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
992extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
993extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
994extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
995extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
996extern void blk_queue_dma_alignment(struct request_queue *, int);
997extern void blk_queue_update_dma_alignment(struct request_queue *, int);
998extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
999extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1000extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1001extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
1002extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1003extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1004
1005extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1006extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
1007 struct scatterlist *sglist);
1008extern void blk_dump_rq_flags(struct request *, char *);
1009extern long nr_blockdev_pages(void);
1010
1011bool __must_check blk_get_queue(struct request_queue *);
1012struct request_queue *blk_alloc_queue(gfp_t);
1013struct request_queue *blk_alloc_queue_node(gfp_t, int);
1014extern void blk_put_queue(struct request_queue *);
1015
1016/*
1017 * block layer runtime pm functions
1018 */
1019#ifdef CONFIG_PM_RUNTIME
1020extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1021extern int blk_pre_runtime_suspend(struct request_queue *q);
1022extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1023extern void blk_pre_runtime_resume(struct request_queue *q);
1024extern void blk_post_runtime_resume(struct request_queue *q, int err);
1025#else
1026static inline void blk_pm_runtime_init(struct request_queue *q,
1027 struct device *dev) {}
1028static inline int blk_pre_runtime_suspend(struct request_queue *q)
1029{
1030 return -ENOSYS;
1031}
1032static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1033static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1034static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1035#endif
1036
1037/*
1038 * blk_plug permits building a queue of related requests by holding the I/O
1039 * fragments for a short period. This allows merging of sequential requests
1040 * into single larger request. As the requests are moved from a per-task list to
1041 * the device's request_queue in a batch, this results in improved scalability
1042 * as the lock contention for request_queue lock is reduced.
1043 *
1044 * It is ok not to disable preemption when adding the request to the plug list
1045 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1046 * the plug list when the task sleeps by itself. For details, please see
1047 * schedule() where blk_schedule_flush_plug() is called.
1048 */
1049struct blk_plug {
1050 unsigned long magic; /* detect uninitialized use-cases */
1051 struct list_head list; /* requests */
1052 struct list_head mq_list; /* blk-mq requests */
1053 struct list_head cb_list; /* md requires an unplug callback */
1054};
1055#define BLK_MAX_REQUEST_COUNT 16
1056
1057struct blk_plug_cb;
1058typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1059struct blk_plug_cb {
1060 struct list_head list;
1061 blk_plug_cb_fn callback;
1062 void *data;
1063};
1064extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1065 void *data, int size);
1066extern void blk_start_plug(struct blk_plug *);
1067extern void blk_finish_plug(struct blk_plug *);
1068extern void blk_flush_plug_list(struct blk_plug *, bool);
1069
1070static inline void blk_flush_plug(struct task_struct *tsk)
1071{
1072 struct blk_plug *plug = tsk->plug;
1073
1074 if (plug)
1075 blk_flush_plug_list(plug, false);
1076}
1077
1078static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1079{
1080 struct blk_plug *plug = tsk->plug;
1081
1082 if (plug)
1083 blk_flush_plug_list(plug, true);
1084}
1085
1086static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1087{
1088 struct blk_plug *plug = tsk->plug;
1089
1090 return plug &&
1091 (!list_empty(&plug->list) ||
1092 !list_empty(&plug->mq_list) ||
1093 !list_empty(&plug->cb_list));
1094}
1095
1096/*
1097 * tag stuff
1098 */
1099#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
1100extern int blk_queue_start_tag(struct request_queue *, struct request *);
1101extern struct request *blk_queue_find_tag(struct request_queue *, int);
1102extern void blk_queue_end_tag(struct request_queue *, struct request *);
1103extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
1104extern void blk_queue_free_tags(struct request_queue *);
1105extern int blk_queue_resize_tags(struct request_queue *, int);
1106extern void blk_queue_invalidate_tags(struct request_queue *);
1107extern struct blk_queue_tag *blk_init_tags(int);
1108extern void blk_free_tags(struct blk_queue_tag *);
1109
1110static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1111 int tag)
1112{
1113 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1114 return NULL;
1115 return bqt->tag_index[tag];
1116}
1117
1118#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1119
1120extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1121extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1122 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1123extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1124 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1125extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1126 sector_t nr_sects, gfp_t gfp_mask);
1127static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1128 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1129{
1130 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1131 nr_blocks << (sb->s_blocksize_bits - 9),
1132 gfp_mask, flags);
1133}
1134static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1135 sector_t nr_blocks, gfp_t gfp_mask)
1136{
1137 return blkdev_issue_zeroout(sb->s_bdev,
1138 block << (sb->s_blocksize_bits - 9),
1139 nr_blocks << (sb->s_blocksize_bits - 9),
1140 gfp_mask);
1141}
1142
1143extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1144
1145enum blk_default_limits {
1146 BLK_MAX_SEGMENTS = 128,
1147 BLK_SAFE_MAX_SECTORS = 255,
1148 BLK_DEF_MAX_SECTORS = 1024,
1149 BLK_MAX_SEGMENT_SIZE = 65536,
1150 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1151};
1152
1153#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1154
1155static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1156{
1157 return q->limits.bounce_pfn;
1158}
1159
1160static inline unsigned long queue_segment_boundary(struct request_queue *q)
1161{
1162 return q->limits.seg_boundary_mask;
1163}
1164
1165static inline unsigned int queue_max_sectors(struct request_queue *q)
1166{
1167 return q->limits.max_sectors;
1168}
1169
1170static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1171{
1172 return q->limits.max_hw_sectors;
1173}
1174
1175static inline unsigned short queue_max_segments(struct request_queue *q)
1176{
1177 return q->limits.max_segments;
1178}
1179
1180static inline unsigned int queue_max_segment_size(struct request_queue *q)
1181{
1182 return q->limits.max_segment_size;
1183}
1184
1185static inline unsigned short queue_logical_block_size(struct request_queue *q)
1186{
1187 int retval = 512;
1188
1189 if (q && q->limits.logical_block_size)
1190 retval = q->limits.logical_block_size;
1191
1192 return retval;
1193}
1194
1195static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1196{
1197 return queue_logical_block_size(bdev_get_queue(bdev));
1198}
1199
1200static inline unsigned int queue_physical_block_size(struct request_queue *q)
1201{
1202 return q->limits.physical_block_size;
1203}
1204
1205static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1206{
1207 return queue_physical_block_size(bdev_get_queue(bdev));
1208}
1209
1210static inline unsigned int queue_io_min(struct request_queue *q)
1211{
1212 return q->limits.io_min;
1213}
1214
1215static inline int bdev_io_min(struct block_device *bdev)
1216{
1217 return queue_io_min(bdev_get_queue(bdev));
1218}
1219
1220static inline unsigned int queue_io_opt(struct request_queue *q)
1221{
1222 return q->limits.io_opt;
1223}
1224
1225static inline int bdev_io_opt(struct block_device *bdev)
1226{
1227 return queue_io_opt(bdev_get_queue(bdev));
1228}
1229
1230static inline int queue_alignment_offset(struct request_queue *q)
1231{
1232 if (q->limits.misaligned)
1233 return -1;
1234
1235 return q->limits.alignment_offset;
1236}
1237
1238static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1239{
1240 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1241 unsigned int alignment = (sector << 9) & (granularity - 1);
1242
1243 return (granularity + lim->alignment_offset - alignment)
1244 & (granularity - 1);
1245}
1246
1247static inline int bdev_alignment_offset(struct block_device *bdev)
1248{
1249 struct request_queue *q = bdev_get_queue(bdev);
1250
1251 if (q->limits.misaligned)
1252 return -1;
1253
1254 if (bdev != bdev->bd_contains)
1255 return bdev->bd_part->alignment_offset;
1256
1257 return q->limits.alignment_offset;
1258}
1259
1260static inline int queue_discard_alignment(struct request_queue *q)
1261{
1262 if (q->limits.discard_misaligned)
1263 return -1;
1264
1265 return q->limits.discard_alignment;
1266}
1267
1268static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1269{
1270 unsigned int alignment, granularity, offset;
1271
1272 if (!lim->max_discard_sectors)
1273 return 0;
1274
1275 /* Why are these in bytes, not sectors? */
1276 alignment = lim->discard_alignment >> 9;
1277 granularity = lim->discard_granularity >> 9;
1278 if (!granularity)
1279 return 0;
1280
1281 /* Offset of the partition start in 'granularity' sectors */
1282 offset = sector_div(sector, granularity);
1283
1284 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1285 offset = (granularity + alignment - offset) % granularity;
1286
1287 /* Turn it back into bytes, gaah */
1288 return offset << 9;
1289}
1290
1291static inline int bdev_discard_alignment(struct block_device *bdev)
1292{
1293 struct request_queue *q = bdev_get_queue(bdev);
1294
1295 if (bdev != bdev->bd_contains)
1296 return bdev->bd_part->discard_alignment;
1297
1298 return q->limits.discard_alignment;
1299}
1300
1301static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1302{
1303 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1304 return 1;
1305
1306 return 0;
1307}
1308
1309static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1310{
1311 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1312}
1313
1314static inline unsigned int bdev_write_same(struct block_device *bdev)
1315{
1316 struct request_queue *q = bdev_get_queue(bdev);
1317
1318 if (q)
1319 return q->limits.max_write_same_sectors;
1320
1321 return 0;
1322}
1323
1324static inline int queue_dma_alignment(struct request_queue *q)
1325{
1326 return q ? q->dma_alignment : 511;
1327}
1328
1329static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1330 unsigned int len)
1331{
1332 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1333 return !(addr & alignment) && !(len & alignment);
1334}
1335
1336/* assumes size > 256 */
1337static inline unsigned int blksize_bits(unsigned int size)
1338{
1339 unsigned int bits = 8;
1340 do {
1341 bits++;
1342 size >>= 1;
1343 } while (size > 256);
1344 return bits;
1345}
1346
1347static inline unsigned int block_size(struct block_device *bdev)
1348{
1349 return bdev->bd_block_size;
1350}
1351
1352static inline bool queue_flush_queueable(struct request_queue *q)
1353{
1354 return !q->flush_not_queueable;
1355}
1356
1357typedef struct {struct page *v;} Sector;
1358
1359unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1360
1361static inline void put_dev_sector(Sector p)
1362{
1363 page_cache_release(p.v);
1364}
1365
1366struct work_struct;
1367int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1368int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
1369
1370#ifdef CONFIG_BLK_CGROUP
1371/*
1372 * This should not be using sched_clock(). A real patch is in progress
1373 * to fix this up, until that is in place we need to disable preemption
1374 * around sched_clock() in this function and set_io_start_time_ns().
1375 */
1376static inline void set_start_time_ns(struct request *req)
1377{
1378 preempt_disable();
1379 req->start_time_ns = sched_clock();
1380 preempt_enable();
1381}
1382
1383static inline void set_io_start_time_ns(struct request *req)
1384{
1385 preempt_disable();
1386 req->io_start_time_ns = sched_clock();
1387 preempt_enable();
1388}
1389
1390static inline uint64_t rq_start_time_ns(struct request *req)
1391{
1392 return req->start_time_ns;
1393}
1394
1395static inline uint64_t rq_io_start_time_ns(struct request *req)
1396{
1397 return req->io_start_time_ns;
1398}
1399#else
1400static inline void set_start_time_ns(struct request *req) {}
1401static inline void set_io_start_time_ns(struct request *req) {}
1402static inline uint64_t rq_start_time_ns(struct request *req)
1403{
1404 return 0;
1405}
1406static inline uint64_t rq_io_start_time_ns(struct request *req)
1407{
1408 return 0;
1409}
1410#endif
1411
1412#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1413 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1414#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1415 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1416
1417#if defined(CONFIG_BLK_DEV_INTEGRITY)
1418
1419#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1420#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1421
1422struct blk_integrity_exchg {
1423 void *prot_buf;
1424 void *data_buf;
1425 sector_t sector;
1426 unsigned int data_size;
1427 unsigned short sector_size;
1428 const char *disk_name;
1429};
1430
1431typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1432typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1433typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1434typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1435
1436struct blk_integrity {
1437 integrity_gen_fn *generate_fn;
1438 integrity_vrfy_fn *verify_fn;
1439 integrity_set_tag_fn *set_tag_fn;
1440 integrity_get_tag_fn *get_tag_fn;
1441
1442 unsigned short flags;
1443 unsigned short tuple_size;
1444 unsigned short sector_size;
1445 unsigned short tag_size;
1446
1447 const char *name;
1448
1449 struct kobject kobj;
1450};
1451
1452extern bool blk_integrity_is_initialized(struct gendisk *);
1453extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1454extern void blk_integrity_unregister(struct gendisk *);
1455extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1456extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1457 struct scatterlist *);
1458extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1459extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1460 struct request *);
1461extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1462 struct bio *);
1463
1464static inline
1465struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1466{
1467 return bdev->bd_disk->integrity;
1468}
1469
1470static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1471{
1472 return disk->integrity;
1473}
1474
1475static inline int blk_integrity_rq(struct request *rq)
1476{
1477 if (rq->bio == NULL)
1478 return 0;
1479
1480 return bio_integrity(rq->bio);
1481}
1482
1483static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1484 unsigned int segs)
1485{
1486 q->limits.max_integrity_segments = segs;
1487}
1488
1489static inline unsigned short
1490queue_max_integrity_segments(struct request_queue *q)
1491{
1492 return q->limits.max_integrity_segments;
1493}
1494
1495#else /* CONFIG_BLK_DEV_INTEGRITY */
1496
1497struct bio;
1498struct block_device;
1499struct gendisk;
1500struct blk_integrity;
1501
1502static inline int blk_integrity_rq(struct request *rq)
1503{
1504 return 0;
1505}
1506static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1507 struct bio *b)
1508{
1509 return 0;
1510}
1511static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1512 struct bio *b,
1513 struct scatterlist *s)
1514{
1515 return 0;
1516}
1517static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1518{
1519 return 0;
1520}
1521static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1522{
1523 return NULL;
1524}
1525static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1526{
1527 return 0;
1528}
1529static inline int blk_integrity_register(struct gendisk *d,
1530 struct blk_integrity *b)
1531{
1532 return 0;
1533}
1534static inline void blk_integrity_unregister(struct gendisk *d)
1535{
1536}
1537static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1538 unsigned int segs)
1539{
1540}
1541static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1542{
1543 return 0;
1544}
1545static inline int blk_integrity_merge_rq(struct request_queue *rq,
1546 struct request *r1,
1547 struct request *r2)
1548{
1549 return 0;
1550}
1551static inline int blk_integrity_merge_bio(struct request_queue *rq,
1552 struct request *r,
1553 struct bio *b)
1554{
1555 return 0;
1556}
1557static inline bool blk_integrity_is_initialized(struct gendisk *g)
1558{
1559 return 0;
1560}
1561
1562#endif /* CONFIG_BLK_DEV_INTEGRITY */
1563
1564struct block_device_operations {
1565 int (*open) (struct block_device *, fmode_t);
1566 void (*release) (struct gendisk *, fmode_t);
1567 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1568 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1569 int (*direct_access) (struct block_device *, sector_t,
1570 void **, unsigned long *);
1571 unsigned int (*check_events) (struct gendisk *disk,
1572 unsigned int clearing);
1573 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1574 int (*media_changed) (struct gendisk *);
1575 void (*unlock_native_capacity) (struct gendisk *);
1576 int (*revalidate_disk) (struct gendisk *);
1577 int (*getgeo)(struct block_device *, struct hd_geometry *);
1578 /* this callback is with swap_lock and sometimes page table lock held */
1579 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1580 struct module *owner;
1581};
1582
1583extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1584 unsigned long);
1585#else /* CONFIG_BLOCK */
1586/*
1587 * stubs for when the block layer is configured out
1588 */
1589#define buffer_heads_over_limit 0
1590
1591static inline long nr_blockdev_pages(void)
1592{
1593 return 0;
1594}
1595
1596struct blk_plug {
1597};
1598
1599static inline void blk_start_plug(struct blk_plug *plug)
1600{
1601}
1602
1603static inline void blk_finish_plug(struct blk_plug *plug)
1604{
1605}
1606
1607static inline void blk_flush_plug(struct task_struct *task)
1608{
1609}
1610
1611static inline void blk_schedule_flush_plug(struct task_struct *task)
1612{
1613}
1614
1615
1616static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1617{
1618 return false;
1619}
1620
1621#endif /* CONFIG_BLOCK */
1622
1623#endif