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