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