projects / deliverable / linux.git / blame_incremental
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (non-incremental) | history | HEAD
block: add support for limiting gaps in SG lists
[deliverable/linux.git] / include / linux / blkdev.h
... / ...
CommitLineData
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 *
95 * If you modify this structure, make sure to update blk_rq_init() and
96 * especially blk_mq_rq_ctx_init() to take care of the added fields.
97 */
98struct request {
99 struct list_head queuelist;
100 union {
101 struct call_single_data csd;
102 unsigned long fifo_time;
103 };
104
105 struct request_queue *q;
106 struct blk_mq_ctx *mq_ctx;
107
108 u64 cmd_flags;
109 enum rq_cmd_type_bits cmd_type;
110 unsigned long atomic_flags;
111
112 int cpu;
113
114 /* the following two fields are internal, NEVER access directly */
115 unsigned int __data_len; /* total data len */
116 sector_t __sector; /* sector cursor */
117
118 struct bio *bio;
119 struct bio *biotail;
120
121 /*
122 * The hash is used inside the scheduler, and killed once the
123 * request reaches the dispatch list. The ipi_list is only used
124 * to queue the request for softirq completion, which is long
125 * after the request has been unhashed (and even removed from
126 * the dispatch list).
127 */
128 union {
129 struct hlist_node hash; /* merge hash */
130 struct list_head ipi_list;
131 };
132
133 /*
134 * The rb_node is only used inside the io scheduler, requests
135 * are pruned when moved to the dispatch queue. So let the
136 * completion_data share space with the rb_node.
137 */
138 union {
139 struct rb_node rb_node; /* sort/lookup */
140 void *completion_data;
141 };
142
143 /*
144 * Three pointers are available for the IO schedulers, if they need
145 * more they have to dynamically allocate it. Flush requests are
146 * never put on the IO scheduler. So let the flush fields share
147 * space with the elevator data.
148 */
149 union {
150 struct {
151 struct io_cq *icq;
152 void *priv[2];
153 } elv;
154
155 struct {
156 unsigned int seq;
157 struct list_head list;
158 rq_end_io_fn *saved_end_io;
159 } flush;
160 };
161
162 struct gendisk *rq_disk;
163 struct hd_struct *part;
164 unsigned long start_time;
165#ifdef CONFIG_BLK_CGROUP
166 struct request_list *rl; /* rl this rq is alloced from */
167 unsigned long long start_time_ns;
168 unsigned long long io_start_time_ns; /* when passed to hardware */
169#endif
170 /* Number of scatter-gather DMA addr+len pairs after
171 * physical address coalescing is performed.
172 */
173 unsigned short nr_phys_segments;
174#if defined(CONFIG_BLK_DEV_INTEGRITY)
175 unsigned short nr_integrity_segments;
176#endif
177
178 unsigned short ioprio;
179
180 void *special; /* opaque pointer available for LLD use */
181
182 int tag;
183 int errors;
184
185 /*
186 * when request is used as a packet command carrier
187 */
188 unsigned char __cmd[BLK_MAX_CDB];
189 unsigned char *cmd;
190 unsigned short cmd_len;
191
192 unsigned int extra_len; /* length of alignment and padding */
193 unsigned int sense_len;
194 unsigned int resid_len; /* residual count */
195 void *sense;
196
197 unsigned long deadline;
198 struct list_head timeout_list;
199 unsigned int timeout;
200 int retries;
201
202 /*
203 * completion callback.
204 */
205 rq_end_io_fn *end_io;
206 void *end_io_data;
207
208 /* for bidi */
209 struct request *next_rq;
210};
211
212static inline unsigned short req_get_ioprio(struct request *req)
213{
214 return req->ioprio;
215}
216
217/*
218 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
219 * requests. Some step values could eventually be made generic.
220 */
221struct request_pm_state
222{
223 /* PM state machine step value, currently driver specific */
224 int pm_step;
225 /* requested PM state value (S1, S2, S3, S4, ...) */
226 u32 pm_state;
227 void* data; /* for driver use */
228};
229
230#include <linux/elevator.h>
231
232struct blk_queue_ctx;
233
234typedef void (request_fn_proc) (struct request_queue *q);
235typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
236typedef int (prep_rq_fn) (struct request_queue *, struct request *);
237typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
238
239struct bio_vec;
240struct bvec_merge_data {
241 struct block_device *bi_bdev;
242 sector_t bi_sector;
243 unsigned bi_size;
244 unsigned long bi_rw;
245};
246typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
247 struct bio_vec *);
248typedef void (softirq_done_fn)(struct request *);
249typedef int (dma_drain_needed_fn)(struct request *);
250typedef int (lld_busy_fn) (struct request_queue *q);
251typedef int (bsg_job_fn) (struct bsg_job *);
252
253enum blk_eh_timer_return {
254 BLK_EH_NOT_HANDLED,
255 BLK_EH_HANDLED,
256 BLK_EH_RESET_TIMER,
257};
258
259typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
260
261enum blk_queue_state {
262 Queue_down,
263 Queue_up,
264};
265
266struct blk_queue_tag {
267 struct request **tag_index; /* map of busy tags */
268 unsigned long *tag_map; /* bit map of free/busy tags */
269 int busy; /* current depth */
270 int max_depth; /* what we will send to device */
271 int real_max_depth; /* what the array can hold */
272 atomic_t refcnt; /* map can be shared */
273};
274
275#define BLK_SCSI_MAX_CMDS (256)
276#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
277
278struct queue_limits {
279 unsigned long bounce_pfn;
280 unsigned long seg_boundary_mask;
281
282 unsigned int max_hw_sectors;
283 unsigned int chunk_sectors;
284 unsigned int max_sectors;
285 unsigned int max_segment_size;
286 unsigned int physical_block_size;
287 unsigned int alignment_offset;
288 unsigned int io_min;
289 unsigned int io_opt;
290 unsigned int max_discard_sectors;
291 unsigned int max_write_same_sectors;
292 unsigned int discard_granularity;
293 unsigned int discard_alignment;
294
295 unsigned short logical_block_size;
296 unsigned short max_segments;
297 unsigned short max_integrity_segments;
298
299 unsigned char misaligned;
300 unsigned char discard_misaligned;
301 unsigned char cluster;
302 unsigned char discard_zeroes_data;
303 unsigned char raid_partial_stripes_expensive;
304};
305
306struct request_queue {
307 /*
308 * Together with queue_head for cacheline sharing
309 */
310 struct list_head queue_head;
311 struct request *last_merge;
312 struct elevator_queue *elevator;
313 int nr_rqs[2]; /* # allocated [a]sync rqs */
314 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
315
316 /*
317 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
318 * is used, root blkg allocates from @q->root_rl and all other
319 * blkgs from their own blkg->rl. Which one to use should be
320 * determined using bio_request_list().
321 */
322 struct request_list root_rl;
323
324 request_fn_proc *request_fn;
325 make_request_fn *make_request_fn;
326 prep_rq_fn *prep_rq_fn;
327 unprep_rq_fn *unprep_rq_fn;
328 merge_bvec_fn *merge_bvec_fn;
329 softirq_done_fn *softirq_done_fn;
330 rq_timed_out_fn *rq_timed_out_fn;
331 dma_drain_needed_fn *dma_drain_needed;
332 lld_busy_fn *lld_busy_fn;
333
334 struct blk_mq_ops *mq_ops;
335
336 unsigned int *mq_map;
337
338 /* sw queues */
339 struct blk_mq_ctx __percpu *queue_ctx;
340 unsigned int nr_queues;
341
342 /* hw dispatch queues */
343 struct blk_mq_hw_ctx **queue_hw_ctx;
344 unsigned int nr_hw_queues;
345
346 /*
347 * Dispatch queue sorting
348 */
349 sector_t end_sector;
350 struct request *boundary_rq;
351
352 /*
353 * Delayed queue handling
354 */
355 struct delayed_work delay_work;
356
357 struct backing_dev_info backing_dev_info;
358
359 /*
360 * The queue owner gets to use this for whatever they like.
361 * ll_rw_blk doesn't touch it.
362 */
363 void *queuedata;
364
365 /*
366 * various queue flags, see QUEUE_* below
367 */
368 unsigned long queue_flags;
369
370 /*
371 * ida allocated id for this queue. Used to index queues from
372 * ioctx.
373 */
374 int id;
375
376 /*
377 * queue needs bounce pages for pages above this limit
378 */
379 gfp_t bounce_gfp;
380
381 /*
382 * protects queue structures from reentrancy. ->__queue_lock should
383 * _never_ be used directly, it is queue private. always use
384 * ->queue_lock.
385 */
386 spinlock_t __queue_lock;
387 spinlock_t *queue_lock;
388
389 /*
390 * queue kobject
391 */
392 struct kobject kobj;
393
394 /*
395 * mq queue kobject
396 */
397 struct kobject mq_kobj;
398
399#ifdef CONFIG_PM_RUNTIME
400 struct device *dev;
401 int rpm_status;
402 unsigned int nr_pending;
403#endif
404
405 /*
406 * queue settings
407 */
408 unsigned long nr_requests; /* Max # of requests */
409 unsigned int nr_congestion_on;
410 unsigned int nr_congestion_off;
411 unsigned int nr_batching;
412
413 unsigned int dma_drain_size;
414 void *dma_drain_buffer;
415 unsigned int dma_pad_mask;
416 unsigned int dma_alignment;
417
418 struct blk_queue_tag *queue_tags;
419 struct list_head tag_busy_list;
420
421 unsigned int nr_sorted;
422 unsigned int in_flight[2];
423 /*
424 * Number of active block driver functions for which blk_drain_queue()
425 * must wait. Must be incremented around functions that unlock the
426 * queue_lock internally, e.g. scsi_request_fn().
427 */
428 unsigned int request_fn_active;
429
430 unsigned int rq_timeout;
431 struct timer_list timeout;
432 struct list_head timeout_list;
433
434 struct list_head icq_list;
435#ifdef CONFIG_BLK_CGROUP
436 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
437 struct blkcg_gq *root_blkg;
438 struct list_head blkg_list;
439#endif
440
441 struct queue_limits limits;
442
443 /*
444 * sg stuff
445 */
446 unsigned int sg_timeout;
447 unsigned int sg_reserved_size;
448 int node;
449#ifdef CONFIG_BLK_DEV_IO_TRACE
450 struct blk_trace *blk_trace;
451#endif
452 /*
453 * for flush operations
454 */
455 unsigned int flush_flags;
456 unsigned int flush_not_queueable:1;
457 unsigned int flush_queue_delayed:1;
458 unsigned int flush_pending_idx:1;
459 unsigned int flush_running_idx:1;
460 unsigned long flush_pending_since;
461 struct list_head flush_queue[2];
462 struct list_head flush_data_in_flight;
463 struct request *flush_rq;
464 spinlock_t mq_flush_lock;
465
466 struct list_head requeue_list;
467 spinlock_t requeue_lock;
468 struct work_struct requeue_work;
469
470 struct mutex sysfs_lock;
471
472 int bypass_depth;
473
474#if defined(CONFIG_BLK_DEV_BSG)
475 bsg_job_fn *bsg_job_fn;
476 int bsg_job_size;
477 struct bsg_class_device bsg_dev;
478#endif
479
480#ifdef CONFIG_BLK_DEV_THROTTLING
481 /* Throttle data */
482 struct throtl_data *td;
483#endif
484 struct rcu_head rcu_head;
485 wait_queue_head_t mq_freeze_wq;
486 struct percpu_counter mq_usage_counter;
487 struct list_head all_q_node;
488
489 struct blk_mq_tag_set *tag_set;
490 struct list_head tag_set_list;
491};
492
493#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
494#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
495#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
496#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
497#define QUEUE_FLAG_DYING 5 /* queue being torn down */
498#define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
499#define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
500#define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
501#define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
502#define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
503#define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
504#define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
505#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
506#define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
507#define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
508#define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
509#define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
510#define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
511#define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
512#define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
513#define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
514#define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
515#define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */
516
517#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
518 (1 << QUEUE_FLAG_STACKABLE) | \
519 (1 << QUEUE_FLAG_SAME_COMP) | \
520 (1 << QUEUE_FLAG_ADD_RANDOM))
521
522#define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
523 (1 << QUEUE_FLAG_SAME_COMP))
524
525static inline void queue_lockdep_assert_held(struct request_queue *q)
526{
527 if (q->queue_lock)
528 lockdep_assert_held(q->queue_lock);
529}
530
531static inline void queue_flag_set_unlocked(unsigned int flag,
532 struct request_queue *q)
533{
534 __set_bit(flag, &q->queue_flags);
535}
536
537static inline int queue_flag_test_and_clear(unsigned int flag,
538 struct request_queue *q)
539{
540 queue_lockdep_assert_held(q);
541
542 if (test_bit(flag, &q->queue_flags)) {
543 __clear_bit(flag, &q->queue_flags);
544 return 1;
545 }
546
547 return 0;
548}
549
550static inline int queue_flag_test_and_set(unsigned int flag,
551 struct request_queue *q)
552{
553 queue_lockdep_assert_held(q);
554
555 if (!test_bit(flag, &q->queue_flags)) {
556 __set_bit(flag, &q->queue_flags);
557 return 0;
558 }
559
560 return 1;
561}
562
563static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
564{
565 queue_lockdep_assert_held(q);
566 __set_bit(flag, &q->queue_flags);
567}
568
569static inline void queue_flag_clear_unlocked(unsigned int flag,
570 struct request_queue *q)
571{
572 __clear_bit(flag, &q->queue_flags);
573}
574
575static inline int queue_in_flight(struct request_queue *q)
576{
577 return q->in_flight[0] + q->in_flight[1];
578}
579
580static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
581{
582 queue_lockdep_assert_held(q);
583 __clear_bit(flag, &q->queue_flags);
584}
585
586#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
587#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
588#define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
589#define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
590#define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
591#define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
592#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
593#define blk_queue_noxmerges(q) \
594 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
595#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
596#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
597#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
598#define blk_queue_stackable(q) \
599 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
600#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
601#define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
602 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
603
604#define blk_noretry_request(rq) \
605 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
606 REQ_FAILFAST_DRIVER))
607
608#define blk_account_rq(rq) \
609 (((rq)->cmd_flags & REQ_STARTED) && \
610 ((rq)->cmd_type == REQ_TYPE_FS))
611
612#define blk_pm_request(rq) \
613 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
614 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
615
616#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
617#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
618/* rq->queuelist of dequeued request must be list_empty() */
619#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
620
621#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
622
623#define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
624
625/*
626 * Driver can handle struct request, if it either has an old style
627 * request_fn defined, or is blk-mq based.
628 */
629static inline bool queue_is_rq_based(struct request_queue *q)
630{
631 return q->request_fn || q->mq_ops;
632}
633
634static inline unsigned int blk_queue_cluster(struct request_queue *q)
635{
636 return q->limits.cluster;
637}
638
639/*
640 * We regard a request as sync, if either a read or a sync write
641 */
642static inline bool rw_is_sync(unsigned int rw_flags)
643{
644 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
645}
646
647static inline bool rq_is_sync(struct request *rq)
648{
649 return rw_is_sync(rq->cmd_flags);
650}
651
652static inline bool blk_rl_full(struct request_list *rl, bool sync)
653{
654 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
655
656 return rl->flags & flag;
657}
658
659static inline void blk_set_rl_full(struct request_list *rl, bool sync)
660{
661 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
662
663 rl->flags |= flag;
664}
665
666static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
667{
668 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
669
670 rl->flags &= ~flag;
671}
672
673static inline bool rq_mergeable(struct request *rq)
674{
675 if (rq->cmd_type != REQ_TYPE_FS)
676 return false;
677
678 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
679 return false;
680
681 return true;
682}
683
684static inline bool blk_check_merge_flags(unsigned int flags1,
685 unsigned int flags2)
686{
687 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
688 return false;
689
690 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
691 return false;
692
693 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
694 return false;
695
696 return true;
697}
698
699static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
700{
701 if (bio_data(a) == bio_data(b))
702 return true;
703
704 return false;
705}
706
707/*
708 * q->prep_rq_fn return values
709 */
710#define BLKPREP_OK 0 /* serve it */
711#define BLKPREP_KILL 1 /* fatal error, kill */
712#define BLKPREP_DEFER 2 /* leave on queue */
713
714extern unsigned long blk_max_low_pfn, blk_max_pfn;
715
716/*
717 * standard bounce addresses:
718 *
719 * BLK_BOUNCE_HIGH : bounce all highmem pages
720 * BLK_BOUNCE_ANY : don't bounce anything
721 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
722 */
723
724#if BITS_PER_LONG == 32
725#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
726#else
727#define BLK_BOUNCE_HIGH -1ULL
728#endif
729#define BLK_BOUNCE_ANY (-1ULL)
730#define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
731
732/*
733 * default timeout for SG_IO if none specified
734 */
735#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
736#define BLK_MIN_SG_TIMEOUT (7 * HZ)
737
738#ifdef CONFIG_BOUNCE
739extern int init_emergency_isa_pool(void);
740extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
741#else
742static inline int init_emergency_isa_pool(void)
743{
744 return 0;
745}
746static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
747{
748}
749#endif /* CONFIG_MMU */
750
751struct rq_map_data {
752 struct page **pages;
753 int page_order;
754 int nr_entries;
755 unsigned long offset;
756 int null_mapped;
757 int from_user;
758};
759
760struct req_iterator {
761 struct bvec_iter iter;
762 struct bio *bio;
763};
764
765/* This should not be used directly - use rq_for_each_segment */
766#define for_each_bio(_bio) \
767 for (; _bio; _bio = _bio->bi_next)
768#define __rq_for_each_bio(_bio, rq) \
769 if ((rq->bio)) \
770 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
771
772#define rq_for_each_segment(bvl, _rq, _iter) \
773 __rq_for_each_bio(_iter.bio, _rq) \
774 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
775
776#define rq_iter_last(bvec, _iter) \
777 (_iter.bio->bi_next == NULL && \
778 bio_iter_last(bvec, _iter.iter))
779
780#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
781# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
782#endif
783#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
784extern void rq_flush_dcache_pages(struct request *rq);
785#else
786static inline void rq_flush_dcache_pages(struct request *rq)
787{
788}
789#endif
790
791extern int blk_register_queue(struct gendisk *disk);
792extern void blk_unregister_queue(struct gendisk *disk);
793extern void generic_make_request(struct bio *bio);
794extern void blk_rq_init(struct request_queue *q, struct request *rq);
795extern void blk_put_request(struct request *);
796extern void __blk_put_request(struct request_queue *, struct request *);
797extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
798extern struct request *blk_make_request(struct request_queue *, struct bio *,
799 gfp_t);
800extern void blk_rq_set_block_pc(struct request *);
801extern void blk_requeue_request(struct request_queue *, struct request *);
802extern void blk_add_request_payload(struct request *rq, struct page *page,
803 unsigned int len);
804extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
805extern int blk_lld_busy(struct request_queue *q);
806extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
807 struct bio_set *bs, gfp_t gfp_mask,
808 int (*bio_ctr)(struct bio *, struct bio *, void *),
809 void *data);
810extern void blk_rq_unprep_clone(struct request *rq);
811extern int blk_insert_cloned_request(struct request_queue *q,
812 struct request *rq);
813extern void blk_delay_queue(struct request_queue *, unsigned long);
814extern void blk_recount_segments(struct request_queue *, struct bio *);
815extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
816extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
817 unsigned int, void __user *);
818extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
819 unsigned int, void __user *);
820extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
821 struct scsi_ioctl_command __user *);
822
823extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
824
825/*
826 * A queue has just exitted congestion. Note this in the global counter of
827 * congested queues, and wake up anyone who was waiting for requests to be
828 * put back.
829 */
830static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
831{
832 clear_bdi_congested(&q->backing_dev_info, sync);
833}
834
835/*
836 * A queue has just entered congestion. Flag that in the queue's VM-visible
837 * state flags and increment the global gounter of congested queues.
838 */
839static inline void blk_set_queue_congested(struct request_queue *q, int sync)
840{
841 set_bdi_congested(&q->backing_dev_info, sync);
842}
843
844extern void blk_start_queue(struct request_queue *q);
845extern void blk_stop_queue(struct request_queue *q);
846extern void blk_sync_queue(struct request_queue *q);
847extern void __blk_stop_queue(struct request_queue *q);
848extern void __blk_run_queue(struct request_queue *q);
849extern void blk_run_queue(struct request_queue *);
850extern void blk_run_queue_async(struct request_queue *q);
851extern int blk_rq_map_user(struct request_queue *, struct request *,
852 struct rq_map_data *, void __user *, unsigned long,
853 gfp_t);
854extern int blk_rq_unmap_user(struct bio *);
855extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
856extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
857 struct rq_map_data *, const struct sg_iovec *,
858 int, unsigned int, gfp_t);
859extern int blk_execute_rq(struct request_queue *, struct gendisk *,
860 struct request *, int);
861extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
862 struct request *, int, rq_end_io_fn *);
863
864static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
865{
866 return bdev->bd_disk->queue;
867}
868
869/*
870 * blk_rq_pos() : the current sector
871 * blk_rq_bytes() : bytes left in the entire request
872 * blk_rq_cur_bytes() : bytes left in the current segment
873 * blk_rq_err_bytes() : bytes left till the next error boundary
874 * blk_rq_sectors() : sectors left in the entire request
875 * blk_rq_cur_sectors() : sectors left in the current segment
876 */
877static inline sector_t blk_rq_pos(const struct request *rq)
878{
879 return rq->__sector;
880}
881
882static inline unsigned int blk_rq_bytes(const struct request *rq)
883{
884 return rq->__data_len;
885}
886
887static inline int blk_rq_cur_bytes(const struct request *rq)
888{
889 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
890}
891
892extern unsigned int blk_rq_err_bytes(const struct request *rq);
893
894static inline unsigned int blk_rq_sectors(const struct request *rq)
895{
896 return blk_rq_bytes(rq) >> 9;
897}
898
899static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
900{
901 return blk_rq_cur_bytes(rq) >> 9;
902}
903
904static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
905 unsigned int cmd_flags)
906{
907 if (unlikely(cmd_flags & REQ_DISCARD))
908 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
909
910 if (unlikely(cmd_flags & REQ_WRITE_SAME))
911 return q->limits.max_write_same_sectors;
912
913 return q->limits.max_sectors;
914}
915
916/*
917 * Return maximum size of a request at given offset. Only valid for
918 * file system requests.
919 */
920static inline unsigned int blk_max_size_offset(struct request_queue *q,
921 sector_t offset)
922{
923 if (!q->limits.chunk_sectors)
924 return q->limits.max_sectors;
925
926 return q->limits.chunk_sectors -
927 (offset & (q->limits.chunk_sectors - 1));
928}
929
930static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
931{
932 struct request_queue *q = rq->q;
933
934 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
935 return q->limits.max_hw_sectors;
936
937 if (!q->limits.chunk_sectors)
938 return blk_queue_get_max_sectors(q, rq->cmd_flags);
939
940 return min(blk_max_size_offset(q, blk_rq_pos(rq)),
941 blk_queue_get_max_sectors(q, rq->cmd_flags));
942}
943
944static inline unsigned int blk_rq_count_bios(struct request *rq)
945{
946 unsigned int nr_bios = 0;
947 struct bio *bio;
948
949 __rq_for_each_bio(bio, rq)
950 nr_bios++;
951
952 return nr_bios;
953}
954
955/*
956 * Request issue related functions.
957 */
958extern struct request *blk_peek_request(struct request_queue *q);
959extern void blk_start_request(struct request *rq);
960extern struct request *blk_fetch_request(struct request_queue *q);
961
962/*
963 * Request completion related functions.
964 *
965 * blk_update_request() completes given number of bytes and updates
966 * the request without completing it.
967 *
968 * blk_end_request() and friends. __blk_end_request() must be called
969 * with the request queue spinlock acquired.
970 *
971 * Several drivers define their own end_request and call
972 * blk_end_request() for parts of the original function.
973 * This prevents code duplication in drivers.
974 */
975extern bool blk_update_request(struct request *rq, int error,
976 unsigned int nr_bytes);
977extern void blk_finish_request(struct request *rq, int error);
978extern bool blk_end_request(struct request *rq, int error,
979 unsigned int nr_bytes);
980extern void blk_end_request_all(struct request *rq, int error);
981extern bool blk_end_request_cur(struct request *rq, int error);
982extern bool blk_end_request_err(struct request *rq, int error);
983extern bool __blk_end_request(struct request *rq, int error,
984 unsigned int nr_bytes);
985extern void __blk_end_request_all(struct request *rq, int error);
986extern bool __blk_end_request_cur(struct request *rq, int error);
987extern bool __blk_end_request_err(struct request *rq, int error);
988
989extern void blk_complete_request(struct request *);
990extern void __blk_complete_request(struct request *);
991extern void blk_abort_request(struct request *);
992extern void blk_unprep_request(struct request *);
993
994/*
995 * Access functions for manipulating queue properties
996 */
997extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
998 spinlock_t *lock, int node_id);
999extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
1000extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
1001 request_fn_proc *, spinlock_t *);
1002extern void blk_cleanup_queue(struct request_queue *);
1003extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
1004extern void blk_queue_bounce_limit(struct request_queue *, u64);
1005extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
1006extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
1007extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int);
1008extern void blk_queue_max_segments(struct request_queue *, unsigned short);
1009extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1010extern void blk_queue_max_discard_sectors(struct request_queue *q,
1011 unsigned int max_discard_sectors);
1012extern void blk_queue_max_write_same_sectors(struct request_queue *q,
1013 unsigned int max_write_same_sectors);
1014extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
1015extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
1016extern void blk_queue_alignment_offset(struct request_queue *q,
1017 unsigned int alignment);
1018extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
1019extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
1020extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
1021extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
1022extern void blk_set_default_limits(struct queue_limits *lim);
1023extern void blk_set_stacking_limits(struct queue_limits *lim);
1024extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
1025 sector_t offset);
1026extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
1027 sector_t offset);
1028extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
1029 sector_t offset);
1030extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1031extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1032extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1033extern int blk_queue_dma_drain(struct request_queue *q,
1034 dma_drain_needed_fn *dma_drain_needed,
1035 void *buf, unsigned int size);
1036extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1037extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1038extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1039extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
1040extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
1041extern void blk_queue_dma_alignment(struct request_queue *, int);
1042extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1043extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1044extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1045extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1046extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
1047extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1048extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1049
1050extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1051extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
1052 struct scatterlist *sglist);
1053extern void blk_dump_rq_flags(struct request *, char *);
1054extern long nr_blockdev_pages(void);
1055
1056bool __must_check blk_get_queue(struct request_queue *);
1057struct request_queue *blk_alloc_queue(gfp_t);
1058struct request_queue *blk_alloc_queue_node(gfp_t, int);
1059extern void blk_put_queue(struct request_queue *);
1060
1061/*
1062 * block layer runtime pm functions
1063 */
1064#ifdef CONFIG_PM_RUNTIME
1065extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1066extern int blk_pre_runtime_suspend(struct request_queue *q);
1067extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1068extern void blk_pre_runtime_resume(struct request_queue *q);
1069extern void blk_post_runtime_resume(struct request_queue *q, int err);
1070#else
1071static inline void blk_pm_runtime_init(struct request_queue *q,
1072 struct device *dev) {}
1073static inline int blk_pre_runtime_suspend(struct request_queue *q)
1074{
1075 return -ENOSYS;
1076}
1077static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1078static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1079static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1080#endif
1081
1082/*
1083 * blk_plug permits building a queue of related requests by holding the I/O
1084 * fragments for a short period. This allows merging of sequential requests
1085 * into single larger request. As the requests are moved from a per-task list to
1086 * the device's request_queue in a batch, this results in improved scalability
1087 * as the lock contention for request_queue lock is reduced.
1088 *
1089 * It is ok not to disable preemption when adding the request to the plug list
1090 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1091 * the plug list when the task sleeps by itself. For details, please see
1092 * schedule() where blk_schedule_flush_plug() is called.
1093 */
1094struct blk_plug {
1095 struct list_head list; /* requests */
1096 struct list_head mq_list; /* blk-mq requests */
1097 struct list_head cb_list; /* md requires an unplug callback */
1098};
1099#define BLK_MAX_REQUEST_COUNT 16
1100
1101struct blk_plug_cb;
1102typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1103struct blk_plug_cb {
1104 struct list_head list;
1105 blk_plug_cb_fn callback;
1106 void *data;
1107};
1108extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1109 void *data, int size);
1110extern void blk_start_plug(struct blk_plug *);
1111extern void blk_finish_plug(struct blk_plug *);
1112extern void blk_flush_plug_list(struct blk_plug *, bool);
1113
1114static inline void blk_flush_plug(struct task_struct *tsk)
1115{
1116 struct blk_plug *plug = tsk->plug;
1117
1118 if (plug)
1119 blk_flush_plug_list(plug, false);
1120}
1121
1122static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1123{
1124 struct blk_plug *plug = tsk->plug;
1125
1126 if (plug)
1127 blk_flush_plug_list(plug, true);
1128}
1129
1130static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1131{
1132 struct blk_plug *plug = tsk->plug;
1133
1134 return plug &&
1135 (!list_empty(&plug->list) ||
1136 !list_empty(&plug->mq_list) ||
1137 !list_empty(&plug->cb_list));
1138}
1139
1140/*
1141 * tag stuff
1142 */
1143#define blk_rq_tagged(rq) \
1144 ((rq)->mq_ctx || ((rq)->cmd_flags & REQ_QUEUED))
1145extern int blk_queue_start_tag(struct request_queue *, struct request *);
1146extern struct request *blk_queue_find_tag(struct request_queue *, int);
1147extern void blk_queue_end_tag(struct request_queue *, struct request *);
1148extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
1149extern void blk_queue_free_tags(struct request_queue *);
1150extern int blk_queue_resize_tags(struct request_queue *, int);
1151extern void blk_queue_invalidate_tags(struct request_queue *);
1152extern struct blk_queue_tag *blk_init_tags(int);
1153extern void blk_free_tags(struct blk_queue_tag *);
1154
1155static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1156 int tag)
1157{
1158 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1159 return NULL;
1160 return bqt->tag_index[tag];
1161}
1162
1163#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1164
1165extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1166extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1167 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1168extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1169 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1170extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1171 sector_t nr_sects, gfp_t gfp_mask);
1172static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1173 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1174{
1175 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1176 nr_blocks << (sb->s_blocksize_bits - 9),
1177 gfp_mask, flags);
1178}
1179static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1180 sector_t nr_blocks, gfp_t gfp_mask)
1181{
1182 return blkdev_issue_zeroout(sb->s_bdev,
1183 block << (sb->s_blocksize_bits - 9),
1184 nr_blocks << (sb->s_blocksize_bits - 9),
1185 gfp_mask);
1186}
1187
1188extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1189
1190enum blk_default_limits {
1191 BLK_MAX_SEGMENTS = 128,
1192 BLK_SAFE_MAX_SECTORS = 255,
1193 BLK_DEF_MAX_SECTORS = 1024,
1194 BLK_MAX_SEGMENT_SIZE = 65536,
1195 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1196};
1197
1198#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1199
1200static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1201{
1202 return q->limits.bounce_pfn;
1203}
1204
1205static inline unsigned long queue_segment_boundary(struct request_queue *q)
1206{
1207 return q->limits.seg_boundary_mask;
1208}
1209
1210static inline unsigned int queue_max_sectors(struct request_queue *q)
1211{
1212 return q->limits.max_sectors;
1213}
1214
1215static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1216{
1217 return q->limits.max_hw_sectors;
1218}
1219
1220static inline unsigned short queue_max_segments(struct request_queue *q)
1221{
1222 return q->limits.max_segments;
1223}
1224
1225static inline unsigned int queue_max_segment_size(struct request_queue *q)
1226{
1227 return q->limits.max_segment_size;
1228}
1229
1230static inline unsigned short queue_logical_block_size(struct request_queue *q)
1231{
1232 int retval = 512;
1233
1234 if (q && q->limits.logical_block_size)
1235 retval = q->limits.logical_block_size;
1236
1237 return retval;
1238}
1239
1240static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1241{
1242 return queue_logical_block_size(bdev_get_queue(bdev));
1243}
1244
1245static inline unsigned int queue_physical_block_size(struct request_queue *q)
1246{
1247 return q->limits.physical_block_size;
1248}
1249
1250static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1251{
1252 return queue_physical_block_size(bdev_get_queue(bdev));
1253}
1254
1255static inline unsigned int queue_io_min(struct request_queue *q)
1256{
1257 return q->limits.io_min;
1258}
1259
1260static inline int bdev_io_min(struct block_device *bdev)
1261{
1262 return queue_io_min(bdev_get_queue(bdev));
1263}
1264
1265static inline unsigned int queue_io_opt(struct request_queue *q)
1266{
1267 return q->limits.io_opt;
1268}
1269
1270static inline int bdev_io_opt(struct block_device *bdev)
1271{
1272 return queue_io_opt(bdev_get_queue(bdev));
1273}
1274
1275static inline int queue_alignment_offset(struct request_queue *q)
1276{
1277 if (q->limits.misaligned)
1278 return -1;
1279
1280 return q->limits.alignment_offset;
1281}
1282
1283static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1284{
1285 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1286 unsigned int alignment = (sector << 9) & (granularity - 1);
1287
1288 return (granularity + lim->alignment_offset - alignment)
1289 & (granularity - 1);
1290}
1291
1292static inline int bdev_alignment_offset(struct block_device *bdev)
1293{
1294 struct request_queue *q = bdev_get_queue(bdev);
1295
1296 if (q->limits.misaligned)
1297 return -1;
1298
1299 if (bdev != bdev->bd_contains)
1300 return bdev->bd_part->alignment_offset;
1301
1302 return q->limits.alignment_offset;
1303}
1304
1305static inline int queue_discard_alignment(struct request_queue *q)
1306{
1307 if (q->limits.discard_misaligned)
1308 return -1;
1309
1310 return q->limits.discard_alignment;
1311}
1312
1313static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1314{
1315 unsigned int alignment, granularity, offset;
1316
1317 if (!lim->max_discard_sectors)
1318 return 0;
1319
1320 /* Why are these in bytes, not sectors? */
1321 alignment = lim->discard_alignment >> 9;
1322 granularity = lim->discard_granularity >> 9;
1323 if (!granularity)
1324 return 0;
1325
1326 /* Offset of the partition start in 'granularity' sectors */
1327 offset = sector_div(sector, granularity);
1328
1329 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1330 offset = (granularity + alignment - offset) % granularity;
1331
1332 /* Turn it back into bytes, gaah */
1333 return offset << 9;
1334}
1335
1336static inline int bdev_discard_alignment(struct block_device *bdev)
1337{
1338 struct request_queue *q = bdev_get_queue(bdev);
1339
1340 if (bdev != bdev->bd_contains)
1341 return bdev->bd_part->discard_alignment;
1342
1343 return q->limits.discard_alignment;
1344}
1345
1346static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1347{
1348 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1349 return 1;
1350
1351 return 0;
1352}
1353
1354static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1355{
1356 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1357}
1358
1359static inline unsigned int bdev_write_same(struct block_device *bdev)
1360{
1361 struct request_queue *q = bdev_get_queue(bdev);
1362
1363 if (q)
1364 return q->limits.max_write_same_sectors;
1365
1366 return 0;
1367}
1368
1369static inline int queue_dma_alignment(struct request_queue *q)
1370{
1371 return q ? q->dma_alignment : 511;
1372}
1373
1374static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1375 unsigned int len)
1376{
1377 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1378 return !(addr & alignment) && !(len & alignment);
1379}
1380
1381/* assumes size > 256 */
1382static inline unsigned int blksize_bits(unsigned int size)
1383{
1384 unsigned int bits = 8;
1385 do {
1386 bits++;
1387 size >>= 1;
1388 } while (size > 256);
1389 return bits;
1390}
1391
1392static inline unsigned int block_size(struct block_device *bdev)
1393{
1394 return bdev->bd_block_size;
1395}
1396
1397static inline bool queue_flush_queueable(struct request_queue *q)
1398{
1399 return !q->flush_not_queueable;
1400}
1401
1402typedef struct {struct page *v;} Sector;
1403
1404unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1405
1406static inline void put_dev_sector(Sector p)
1407{
1408 page_cache_release(p.v);
1409}
1410
1411struct work_struct;
1412int kblockd_schedule_work(struct work_struct *work);
1413int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
1414int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
1415
1416#ifdef CONFIG_BLK_CGROUP
1417/*
1418 * This should not be using sched_clock(). A real patch is in progress
1419 * to fix this up, until that is in place we need to disable preemption
1420 * around sched_clock() in this function and set_io_start_time_ns().
1421 */
1422static inline void set_start_time_ns(struct request *req)
1423{
1424 preempt_disable();
1425 req->start_time_ns = sched_clock();
1426 preempt_enable();
1427}
1428
1429static inline void set_io_start_time_ns(struct request *req)
1430{
1431 preempt_disable();
1432 req->io_start_time_ns = sched_clock();
1433 preempt_enable();
1434}
1435
1436static inline uint64_t rq_start_time_ns(struct request *req)
1437{
1438 return req->start_time_ns;
1439}
1440
1441static inline uint64_t rq_io_start_time_ns(struct request *req)
1442{
1443 return req->io_start_time_ns;
1444}
1445#else
1446static inline void set_start_time_ns(struct request *req) {}
1447static inline void set_io_start_time_ns(struct request *req) {}
1448static inline uint64_t rq_start_time_ns(struct request *req)
1449{
1450 return 0;
1451}
1452static inline uint64_t rq_io_start_time_ns(struct request *req)
1453{
1454 return 0;
1455}
1456#endif
1457
1458#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1459 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1460#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1461 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1462
1463#if defined(CONFIG_BLK_DEV_INTEGRITY)
1464
1465#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1466#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1467
1468struct blk_integrity_exchg {
1469 void *prot_buf;
1470 void *data_buf;
1471 sector_t sector;
1472 unsigned int data_size;
1473 unsigned short sector_size;
1474 const char *disk_name;
1475};
1476
1477typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1478typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1479typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1480typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1481
1482struct blk_integrity {
1483 integrity_gen_fn *generate_fn;
1484 integrity_vrfy_fn *verify_fn;
1485 integrity_set_tag_fn *set_tag_fn;
1486 integrity_get_tag_fn *get_tag_fn;
1487
1488 unsigned short flags;
1489 unsigned short tuple_size;
1490 unsigned short sector_size;
1491 unsigned short tag_size;
1492
1493 const char *name;
1494
1495 struct kobject kobj;
1496};
1497
1498extern bool blk_integrity_is_initialized(struct gendisk *);
1499extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1500extern void blk_integrity_unregister(struct gendisk *);
1501extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1502extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1503 struct scatterlist *);
1504extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1505extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1506 struct request *);
1507extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1508 struct bio *);
1509
1510static inline
1511struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1512{
1513 return bdev->bd_disk->integrity;
1514}
1515
1516static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1517{
1518 return disk->integrity;
1519}
1520
1521static inline int blk_integrity_rq(struct request *rq)
1522{
1523 if (rq->bio == NULL)
1524 return 0;
1525
1526 return bio_integrity(rq->bio);
1527}
1528
1529static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1530 unsigned int segs)
1531{
1532 q->limits.max_integrity_segments = segs;
1533}
1534
1535static inline unsigned short
1536queue_max_integrity_segments(struct request_queue *q)
1537{
1538 return q->limits.max_integrity_segments;
1539}
1540
1541#else /* CONFIG_BLK_DEV_INTEGRITY */
1542
1543struct bio;
1544struct block_device;
1545struct gendisk;
1546struct blk_integrity;
1547
1548static inline int blk_integrity_rq(struct request *rq)
1549{
1550 return 0;
1551}
1552static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1553 struct bio *b)
1554{
1555 return 0;
1556}
1557static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1558 struct bio *b,
1559 struct scatterlist *s)
1560{
1561 return 0;
1562}
1563static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1564{
1565 return 0;
1566}
1567static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1568{
1569 return NULL;
1570}
1571static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1572{
1573 return 0;
1574}
1575static inline int blk_integrity_register(struct gendisk *d,
1576 struct blk_integrity *b)
1577{
1578 return 0;
1579}
1580static inline void blk_integrity_unregister(struct gendisk *d)
1581{
1582}
1583static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1584 unsigned int segs)
1585{
1586}
1587static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1588{
1589 return 0;
1590}
1591static inline int blk_integrity_merge_rq(struct request_queue *rq,
1592 struct request *r1,
1593 struct request *r2)
1594{
1595 return 0;
1596}
1597static inline int blk_integrity_merge_bio(struct request_queue *rq,
1598 struct request *r,
1599 struct bio *b)
1600{
1601 return 0;
1602}
1603static inline bool blk_integrity_is_initialized(struct gendisk *g)
1604{
1605 return 0;
1606}
1607
1608#endif /* CONFIG_BLK_DEV_INTEGRITY */
1609
1610struct block_device_operations {
1611 int (*open) (struct block_device *, fmode_t);
1612 void (*release) (struct gendisk *, fmode_t);
1613 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
1614 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1615 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1616 int (*direct_access) (struct block_device *, sector_t,
1617 void **, unsigned long *);
1618 unsigned int (*check_events) (struct gendisk *disk,
1619 unsigned int clearing);
1620 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1621 int (*media_changed) (struct gendisk *);
1622 void (*unlock_native_capacity) (struct gendisk *);
1623 int (*revalidate_disk) (struct gendisk *);
1624 int (*getgeo)(struct block_device *, struct hd_geometry *);
1625 /* this callback is with swap_lock and sometimes page table lock held */
1626 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1627 struct module *owner;
1628};
1629
1630extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1631 unsigned long);
1632extern int bdev_read_page(struct block_device *, sector_t, struct page *);
1633extern int bdev_write_page(struct block_device *, sector_t, struct page *,
1634 struct writeback_control *);
1635#else /* CONFIG_BLOCK */
1636
1637struct block_device;
1638
1639/*
1640 * stubs for when the block layer is configured out
1641 */
1642#define buffer_heads_over_limit 0
1643
1644static inline long nr_blockdev_pages(void)
1645{
1646 return 0;
1647}
1648
1649struct blk_plug {
1650};
1651
1652static inline void blk_start_plug(struct blk_plug *plug)
1653{
1654}
1655
1656static inline void blk_finish_plug(struct blk_plug *plug)
1657{
1658}
1659
1660static inline void blk_flush_plug(struct task_struct *task)
1661{
1662}
1663
1664static inline void blk_schedule_flush_plug(struct task_struct *task)
1665{
1666}
1667
1668
1669static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1670{
1671 return false;
1672}
1673
1674static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
1675 sector_t *error_sector)
1676{
1677 return 0;
1678}
1679
1680#endif /* CONFIG_BLOCK */
1681
1682#endif
Linux kernel - Deliverables
This page took 0.029337 seconds and 5 git commands to generate.