include: replace linux/module.h with "struct module" wherever possible
[linux-2.6/next.git] / include / linux / blkdev.h
blob0e484b9d08d46064f88ea7e0a5d7e22b4a0e7982
1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
4 #ifdef CONFIG_BLOCK
6 #include <linux/sched.h>
7 #include <linux/major.h>
8 #include <linux/genhd.h>
9 #include <linux/list.h>
10 #include <linux/timer.h>
11 #include <linux/workqueue.h>
12 #include <linux/pagemap.h>
13 #include <linux/backing-dev.h>
14 #include <linux/wait.h>
15 #include <linux/mempool.h>
16 #include <linux/bio.h>
17 #include <linux/stringify.h>
18 #include <linux/gfp.h>
19 #include <linux/bsg.h>
20 #include <linux/smp.h>
22 #include <asm/scatterlist.h>
24 struct module;
25 struct scsi_ioctl_command;
27 struct request_queue;
28 struct elevator_queue;
29 struct request_pm_state;
30 struct blk_trace;
31 struct request;
32 struct sg_io_hdr;
34 #define BLKDEV_MIN_RQ 4
35 #define BLKDEV_MAX_RQ 128 /* Default maximum */
37 struct request;
38 typedef void (rq_end_io_fn)(struct request *, int);
40 struct request_list {
42 * count[], starved[], and wait[] are indexed by
43 * BLK_RW_SYNC/BLK_RW_ASYNC
45 int count[2];
46 int starved[2];
47 int elvpriv;
48 mempool_t *rq_pool;
49 wait_queue_head_t wait[2];
53 * request command types
55 enum rq_cmd_type_bits {
56 REQ_TYPE_FS = 1, /* fs request */
57 REQ_TYPE_BLOCK_PC, /* scsi command */
58 REQ_TYPE_SENSE, /* sense request */
59 REQ_TYPE_PM_SUSPEND, /* suspend request */
60 REQ_TYPE_PM_RESUME, /* resume request */
61 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
62 REQ_TYPE_SPECIAL, /* driver defined type */
64 * for ATA/ATAPI devices. this really doesn't belong here, ide should
65 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
66 * private REQ_LB opcodes to differentiate what type of request this is
68 REQ_TYPE_ATA_TASKFILE,
69 REQ_TYPE_ATA_PC,
72 #define BLK_MAX_CDB 16
75 * try to put the fields that are referenced together in the same cacheline.
76 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
77 * as well!
79 struct request {
80 struct list_head queuelist;
81 struct call_single_data csd;
83 struct request_queue *q;
85 unsigned int cmd_flags;
86 enum rq_cmd_type_bits cmd_type;
87 unsigned long atomic_flags;
89 int cpu;
91 /* the following two fields are internal, NEVER access directly */
92 unsigned int __data_len; /* total data len */
93 sector_t __sector; /* sector cursor */
95 struct bio *bio;
96 struct bio *biotail;
98 struct hlist_node hash; /* merge hash */
100 * The rb_node is only used inside the io scheduler, requests
101 * are pruned when moved to the dispatch queue. So let the
102 * completion_data share space with the rb_node.
104 union {
105 struct rb_node rb_node; /* sort/lookup */
106 void *completion_data;
110 * Three pointers are available for the IO schedulers, if they need
111 * more they have to dynamically allocate it. Flush requests are
112 * never put on the IO scheduler. So let the flush fields share
113 * space with the three elevator_private pointers.
115 union {
116 void *elevator_private[3];
117 struct {
118 unsigned int seq;
119 struct list_head list;
120 } flush;
123 struct gendisk *rq_disk;
124 struct hd_struct *part;
125 unsigned long start_time;
126 #ifdef CONFIG_BLK_CGROUP
127 unsigned long long start_time_ns;
128 unsigned long long io_start_time_ns; /* when passed to hardware */
129 #endif
130 /* Number of scatter-gather DMA addr+len pairs after
131 * physical address coalescing is performed.
133 unsigned short nr_phys_segments;
134 #if defined(CONFIG_BLK_DEV_INTEGRITY)
135 unsigned short nr_integrity_segments;
136 #endif
138 unsigned short ioprio;
140 int ref_count;
142 void *special; /* opaque pointer available for LLD use */
143 char *buffer; /* kaddr of the current segment if available */
145 int tag;
146 int errors;
149 * when request is used as a packet command carrier
151 unsigned char __cmd[BLK_MAX_CDB];
152 unsigned char *cmd;
153 unsigned short cmd_len;
155 unsigned int extra_len; /* length of alignment and padding */
156 unsigned int sense_len;
157 unsigned int resid_len; /* residual count */
158 void *sense;
160 unsigned long deadline;
161 struct list_head timeout_list;
162 unsigned int timeout;
163 int retries;
166 * completion callback.
168 rq_end_io_fn *end_io;
169 void *end_io_data;
171 /* for bidi */
172 struct request *next_rq;
175 static inline unsigned short req_get_ioprio(struct request *req)
177 return req->ioprio;
181 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
182 * requests. Some step values could eventually be made generic.
184 struct request_pm_state
186 /* PM state machine step value, currently driver specific */
187 int pm_step;
188 /* requested PM state value (S1, S2, S3, S4, ...) */
189 u32 pm_state;
190 void* data; /* for driver use */
193 #include <linux/elevator.h>
195 typedef void (request_fn_proc) (struct request_queue *q);
196 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
197 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
198 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
200 struct bio_vec;
201 struct bvec_merge_data {
202 struct block_device *bi_bdev;
203 sector_t bi_sector;
204 unsigned bi_size;
205 unsigned long bi_rw;
207 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
208 struct bio_vec *);
209 typedef void (softirq_done_fn)(struct request *);
210 typedef int (dma_drain_needed_fn)(struct request *);
211 typedef int (lld_busy_fn) (struct request_queue *q);
213 enum blk_eh_timer_return {
214 BLK_EH_NOT_HANDLED,
215 BLK_EH_HANDLED,
216 BLK_EH_RESET_TIMER,
219 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
221 enum blk_queue_state {
222 Queue_down,
223 Queue_up,
226 struct blk_queue_tag {
227 struct request **tag_index; /* map of busy tags */
228 unsigned long *tag_map; /* bit map of free/busy tags */
229 int busy; /* current depth */
230 int max_depth; /* what we will send to device */
231 int real_max_depth; /* what the array can hold */
232 atomic_t refcnt; /* map can be shared */
235 #define BLK_SCSI_MAX_CMDS (256)
236 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
238 struct queue_limits {
239 unsigned long bounce_pfn;
240 unsigned long seg_boundary_mask;
242 unsigned int max_hw_sectors;
243 unsigned int max_sectors;
244 unsigned int max_segment_size;
245 unsigned int physical_block_size;
246 unsigned int alignment_offset;
247 unsigned int io_min;
248 unsigned int io_opt;
249 unsigned int max_discard_sectors;
250 unsigned int discard_granularity;
251 unsigned int discard_alignment;
253 unsigned short logical_block_size;
254 unsigned short max_segments;
255 unsigned short max_integrity_segments;
257 unsigned char misaligned;
258 unsigned char discard_misaligned;
259 unsigned char cluster;
260 unsigned char discard_zeroes_data;
263 struct request_queue {
265 * Together with queue_head for cacheline sharing
267 struct list_head queue_head;
268 struct request *last_merge;
269 struct elevator_queue *elevator;
272 * the queue request freelist, one for reads and one for writes
274 struct request_list rq;
276 request_fn_proc *request_fn;
277 make_request_fn *make_request_fn;
278 prep_rq_fn *prep_rq_fn;
279 unprep_rq_fn *unprep_rq_fn;
280 merge_bvec_fn *merge_bvec_fn;
281 softirq_done_fn *softirq_done_fn;
282 rq_timed_out_fn *rq_timed_out_fn;
283 dma_drain_needed_fn *dma_drain_needed;
284 lld_busy_fn *lld_busy_fn;
287 * Dispatch queue sorting
289 sector_t end_sector;
290 struct request *boundary_rq;
293 * Delayed queue handling
295 struct delayed_work delay_work;
297 struct backing_dev_info backing_dev_info;
300 * The queue owner gets to use this for whatever they like.
301 * ll_rw_blk doesn't touch it.
303 void *queuedata;
306 * various queue flags, see QUEUE_* below
308 unsigned long queue_flags;
311 * queue needs bounce pages for pages above this limit
313 gfp_t bounce_gfp;
316 * protects queue structures from reentrancy. ->__queue_lock should
317 * _never_ be used directly, it is queue private. always use
318 * ->queue_lock.
320 spinlock_t __queue_lock;
321 spinlock_t *queue_lock;
324 * queue kobject
326 struct kobject kobj;
329 * queue settings
331 unsigned long nr_requests; /* Max # of requests */
332 unsigned int nr_congestion_on;
333 unsigned int nr_congestion_off;
334 unsigned int nr_batching;
336 unsigned int dma_drain_size;
337 void *dma_drain_buffer;
338 unsigned int dma_pad_mask;
339 unsigned int dma_alignment;
341 struct blk_queue_tag *queue_tags;
342 struct list_head tag_busy_list;
344 unsigned int nr_sorted;
345 unsigned int in_flight[2];
347 unsigned int rq_timeout;
348 struct timer_list timeout;
349 struct list_head timeout_list;
351 struct queue_limits limits;
354 * sg stuff
356 unsigned int sg_timeout;
357 unsigned int sg_reserved_size;
358 int node;
359 #ifdef CONFIG_BLK_DEV_IO_TRACE
360 struct blk_trace *blk_trace;
361 #endif
363 * for flush operations
365 unsigned int flush_flags;
366 unsigned int flush_not_queueable:1;
367 unsigned int flush_queue_delayed:1;
368 unsigned int flush_pending_idx:1;
369 unsigned int flush_running_idx:1;
370 unsigned long flush_pending_since;
371 struct list_head flush_queue[2];
372 struct list_head flush_data_in_flight;
373 struct request flush_rq;
375 struct mutex sysfs_lock;
377 #if defined(CONFIG_BLK_DEV_BSG)
378 struct bsg_class_device bsg_dev;
379 #endif
381 #ifdef CONFIG_BLK_DEV_THROTTLING
382 /* Throttle data */
383 struct throtl_data *td;
384 #endif
387 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
388 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
389 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
390 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
391 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
392 #define QUEUE_FLAG_ELVSWITCH 6 /* don't use elevator, just do FIFO */
393 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
394 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
395 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
396 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
397 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
398 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
399 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
400 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
401 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
402 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
403 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
404 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
405 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
407 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
408 (1 << QUEUE_FLAG_STACKABLE) | \
409 (1 << QUEUE_FLAG_SAME_COMP) | \
410 (1 << QUEUE_FLAG_ADD_RANDOM))
412 static inline int queue_is_locked(struct request_queue *q)
414 #ifdef CONFIG_SMP
415 spinlock_t *lock = q->queue_lock;
416 return lock && spin_is_locked(lock);
417 #else
418 return 1;
419 #endif
422 static inline void queue_flag_set_unlocked(unsigned int flag,
423 struct request_queue *q)
425 __set_bit(flag, &q->queue_flags);
428 static inline int queue_flag_test_and_clear(unsigned int flag,
429 struct request_queue *q)
431 WARN_ON_ONCE(!queue_is_locked(q));
433 if (test_bit(flag, &q->queue_flags)) {
434 __clear_bit(flag, &q->queue_flags);
435 return 1;
438 return 0;
441 static inline int queue_flag_test_and_set(unsigned int flag,
442 struct request_queue *q)
444 WARN_ON_ONCE(!queue_is_locked(q));
446 if (!test_bit(flag, &q->queue_flags)) {
447 __set_bit(flag, &q->queue_flags);
448 return 0;
451 return 1;
454 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
456 WARN_ON_ONCE(!queue_is_locked(q));
457 __set_bit(flag, &q->queue_flags);
460 static inline void queue_flag_clear_unlocked(unsigned int flag,
461 struct request_queue *q)
463 __clear_bit(flag, &q->queue_flags);
466 static inline int queue_in_flight(struct request_queue *q)
468 return q->in_flight[0] + q->in_flight[1];
471 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
473 WARN_ON_ONCE(!queue_is_locked(q));
474 __clear_bit(flag, &q->queue_flags);
477 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
478 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
479 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
480 #define blk_queue_noxmerges(q) \
481 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
482 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
483 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
484 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
485 #define blk_queue_stackable(q) \
486 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
487 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
488 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
489 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
491 #define blk_noretry_request(rq) \
492 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
493 REQ_FAILFAST_DRIVER))
495 #define blk_account_rq(rq) \
496 (((rq)->cmd_flags & REQ_STARTED) && \
497 ((rq)->cmd_type == REQ_TYPE_FS || \
498 ((rq)->cmd_flags & REQ_DISCARD)))
500 #define blk_pm_request(rq) \
501 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
502 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
504 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
505 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
506 /* rq->queuelist of dequeued request must be list_empty() */
507 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
509 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
511 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
513 static inline unsigned int blk_queue_cluster(struct request_queue *q)
515 return q->limits.cluster;
519 * We regard a request as sync, if either a read or a sync write
521 static inline bool rw_is_sync(unsigned int rw_flags)
523 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
526 static inline bool rq_is_sync(struct request *rq)
528 return rw_is_sync(rq->cmd_flags);
531 static inline int blk_queue_full(struct request_queue *q, int sync)
533 if (sync)
534 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
535 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
538 static inline void blk_set_queue_full(struct request_queue *q, int sync)
540 if (sync)
541 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
542 else
543 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
546 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
548 if (sync)
549 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
550 else
551 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
556 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
557 * it already be started by driver.
559 #define RQ_NOMERGE_FLAGS \
560 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
561 #define rq_mergeable(rq) \
562 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
563 (((rq)->cmd_flags & REQ_DISCARD) || \
564 (rq)->cmd_type == REQ_TYPE_FS))
567 * q->prep_rq_fn return values
569 #define BLKPREP_OK 0 /* serve it */
570 #define BLKPREP_KILL 1 /* fatal error, kill */
571 #define BLKPREP_DEFER 2 /* leave on queue */
573 extern unsigned long blk_max_low_pfn, blk_max_pfn;
576 * standard bounce addresses:
578 * BLK_BOUNCE_HIGH : bounce all highmem pages
579 * BLK_BOUNCE_ANY : don't bounce anything
580 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
583 #if BITS_PER_LONG == 32
584 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
585 #else
586 #define BLK_BOUNCE_HIGH -1ULL
587 #endif
588 #define BLK_BOUNCE_ANY (-1ULL)
589 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
592 * default timeout for SG_IO if none specified
594 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
595 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
597 #ifdef CONFIG_BOUNCE
598 extern int init_emergency_isa_pool(void);
599 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
600 #else
601 static inline int init_emergency_isa_pool(void)
603 return 0;
605 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
608 #endif /* CONFIG_MMU */
610 struct rq_map_data {
611 struct page **pages;
612 int page_order;
613 int nr_entries;
614 unsigned long offset;
615 int null_mapped;
616 int from_user;
619 struct req_iterator {
620 int i;
621 struct bio *bio;
624 /* This should not be used directly - use rq_for_each_segment */
625 #define for_each_bio(_bio) \
626 for (; _bio; _bio = _bio->bi_next)
627 #define __rq_for_each_bio(_bio, rq) \
628 if ((rq->bio)) \
629 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
631 #define rq_for_each_segment(bvl, _rq, _iter) \
632 __rq_for_each_bio(_iter.bio, _rq) \
633 bio_for_each_segment(bvl, _iter.bio, _iter.i)
635 #define rq_iter_last(rq, _iter) \
636 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
638 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
639 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
640 #endif
641 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
642 extern void rq_flush_dcache_pages(struct request *rq);
643 #else
644 static inline void rq_flush_dcache_pages(struct request *rq)
647 #endif
649 extern int blk_register_queue(struct gendisk *disk);
650 extern void blk_unregister_queue(struct gendisk *disk);
651 extern void generic_make_request(struct bio *bio);
652 extern void blk_rq_init(struct request_queue *q, struct request *rq);
653 extern void blk_put_request(struct request *);
654 extern void __blk_put_request(struct request_queue *, struct request *);
655 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
656 extern struct request *blk_make_request(struct request_queue *, struct bio *,
657 gfp_t);
658 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
659 extern void blk_requeue_request(struct request_queue *, struct request *);
660 extern void blk_add_request_payload(struct request *rq, struct page *page,
661 unsigned int len);
662 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
663 extern int blk_lld_busy(struct request_queue *q);
664 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
665 struct bio_set *bs, gfp_t gfp_mask,
666 int (*bio_ctr)(struct bio *, struct bio *, void *),
667 void *data);
668 extern void blk_rq_unprep_clone(struct request *rq);
669 extern int blk_insert_cloned_request(struct request_queue *q,
670 struct request *rq);
671 extern void blk_delay_queue(struct request_queue *, unsigned long);
672 extern void blk_recount_segments(struct request_queue *, struct bio *);
673 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
674 unsigned int, void __user *);
675 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
676 struct scsi_ioctl_command __user *);
679 * A queue has just exitted congestion. Note this in the global counter of
680 * congested queues, and wake up anyone who was waiting for requests to be
681 * put back.
683 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
685 clear_bdi_congested(&q->backing_dev_info, sync);
689 * A queue has just entered congestion. Flag that in the queue's VM-visible
690 * state flags and increment the global gounter of congested queues.
692 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
694 set_bdi_congested(&q->backing_dev_info, sync);
697 extern void blk_start_queue(struct request_queue *q);
698 extern void blk_stop_queue(struct request_queue *q);
699 extern void blk_sync_queue(struct request_queue *q);
700 extern void __blk_stop_queue(struct request_queue *q);
701 extern void __blk_run_queue(struct request_queue *q);
702 extern void blk_run_queue(struct request_queue *);
703 extern void blk_run_queue_async(struct request_queue *q);
704 extern int blk_rq_map_user(struct request_queue *, struct request *,
705 struct rq_map_data *, void __user *, unsigned long,
706 gfp_t);
707 extern int blk_rq_unmap_user(struct bio *);
708 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
709 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
710 struct rq_map_data *, struct sg_iovec *, int,
711 unsigned int, gfp_t);
712 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
713 struct request *, int);
714 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
715 struct request *, int, rq_end_io_fn *);
717 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
719 return bdev->bd_disk->queue;
723 * blk_rq_pos() : the current sector
724 * blk_rq_bytes() : bytes left in the entire request
725 * blk_rq_cur_bytes() : bytes left in the current segment
726 * blk_rq_err_bytes() : bytes left till the next error boundary
727 * blk_rq_sectors() : sectors left in the entire request
728 * blk_rq_cur_sectors() : sectors left in the current segment
730 static inline sector_t blk_rq_pos(const struct request *rq)
732 return rq->__sector;
735 static inline unsigned int blk_rq_bytes(const struct request *rq)
737 return rq->__data_len;
740 static inline int blk_rq_cur_bytes(const struct request *rq)
742 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
745 extern unsigned int blk_rq_err_bytes(const struct request *rq);
747 static inline unsigned int blk_rq_sectors(const struct request *rq)
749 return blk_rq_bytes(rq) >> 9;
752 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
754 return blk_rq_cur_bytes(rq) >> 9;
758 * Request issue related functions.
760 extern struct request *blk_peek_request(struct request_queue *q);
761 extern void blk_start_request(struct request *rq);
762 extern struct request *blk_fetch_request(struct request_queue *q);
765 * Request completion related functions.
767 * blk_update_request() completes given number of bytes and updates
768 * the request without completing it.
770 * blk_end_request() and friends. __blk_end_request() must be called
771 * with the request queue spinlock acquired.
773 * Several drivers define their own end_request and call
774 * blk_end_request() for parts of the original function.
775 * This prevents code duplication in drivers.
777 extern bool blk_update_request(struct request *rq, int error,
778 unsigned int nr_bytes);
779 extern bool blk_end_request(struct request *rq, int error,
780 unsigned int nr_bytes);
781 extern void blk_end_request_all(struct request *rq, int error);
782 extern bool blk_end_request_cur(struct request *rq, int error);
783 extern bool blk_end_request_err(struct request *rq, int error);
784 extern bool __blk_end_request(struct request *rq, int error,
785 unsigned int nr_bytes);
786 extern void __blk_end_request_all(struct request *rq, int error);
787 extern bool __blk_end_request_cur(struct request *rq, int error);
788 extern bool __blk_end_request_err(struct request *rq, int error);
790 extern void blk_complete_request(struct request *);
791 extern void __blk_complete_request(struct request *);
792 extern void blk_abort_request(struct request *);
793 extern void blk_abort_queue(struct request_queue *);
794 extern void blk_unprep_request(struct request *);
797 * Access functions for manipulating queue properties
799 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
800 spinlock_t *lock, int node_id);
801 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
802 request_fn_proc *,
803 spinlock_t *, int node_id);
804 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
805 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
806 request_fn_proc *, spinlock_t *);
807 extern void blk_cleanup_queue(struct request_queue *);
808 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
809 extern void blk_queue_bounce_limit(struct request_queue *, u64);
810 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
811 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
812 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
813 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
814 extern void blk_queue_max_discard_sectors(struct request_queue *q,
815 unsigned int max_discard_sectors);
816 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
817 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
818 extern void blk_queue_alignment_offset(struct request_queue *q,
819 unsigned int alignment);
820 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
821 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
822 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
823 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
824 extern void blk_set_default_limits(struct queue_limits *lim);
825 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
826 sector_t offset);
827 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
828 sector_t offset);
829 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
830 sector_t offset);
831 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
832 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
833 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
834 extern int blk_queue_dma_drain(struct request_queue *q,
835 dma_drain_needed_fn *dma_drain_needed,
836 void *buf, unsigned int size);
837 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
838 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
839 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
840 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
841 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
842 extern void blk_queue_dma_alignment(struct request_queue *, int);
843 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
844 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
845 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
846 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
847 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
848 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
849 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
851 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
852 extern void blk_dump_rq_flags(struct request *, char *);
853 extern long nr_blockdev_pages(void);
855 int blk_get_queue(struct request_queue *);
856 struct request_queue *blk_alloc_queue(gfp_t);
857 struct request_queue *blk_alloc_queue_node(gfp_t, int);
858 extern void blk_put_queue(struct request_queue *);
861 * Note: Code in between changing the blk_plug list/cb_list or element of such
862 * lists is preemptable, but such code can't do sleep (or be very careful),
863 * otherwise data is corrupted. For details, please check schedule() where
864 * blk_schedule_flush_plug() is called.
866 struct blk_plug {
867 unsigned long magic;
868 struct list_head list;
869 struct list_head cb_list;
870 unsigned int should_sort;
871 unsigned int count;
873 #define BLK_MAX_REQUEST_COUNT 16
875 struct blk_plug_cb {
876 struct list_head list;
877 void (*callback)(struct blk_plug_cb *);
880 extern void blk_start_plug(struct blk_plug *);
881 extern void blk_finish_plug(struct blk_plug *);
882 extern void blk_flush_plug_list(struct blk_plug *, bool);
884 static inline void blk_flush_plug(struct task_struct *tsk)
886 struct blk_plug *plug = tsk->plug;
888 if (plug)
889 blk_flush_plug_list(plug, false);
892 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
894 struct blk_plug *plug = tsk->plug;
896 if (plug)
897 blk_flush_plug_list(plug, true);
900 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
902 struct blk_plug *plug = tsk->plug;
904 return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
908 * tag stuff
910 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
911 extern int blk_queue_start_tag(struct request_queue *, struct request *);
912 extern struct request *blk_queue_find_tag(struct request_queue *, int);
913 extern void blk_queue_end_tag(struct request_queue *, struct request *);
914 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
915 extern void blk_queue_free_tags(struct request_queue *);
916 extern int blk_queue_resize_tags(struct request_queue *, int);
917 extern void blk_queue_invalidate_tags(struct request_queue *);
918 extern struct blk_queue_tag *blk_init_tags(int);
919 extern void blk_free_tags(struct blk_queue_tag *);
921 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
922 int tag)
924 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
925 return NULL;
926 return bqt->tag_index[tag];
929 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
931 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
932 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
933 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
934 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
935 sector_t nr_sects, gfp_t gfp_mask);
936 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
937 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
939 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
940 nr_blocks << (sb->s_blocksize_bits - 9),
941 gfp_mask, flags);
943 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
944 sector_t nr_blocks, gfp_t gfp_mask)
946 return blkdev_issue_zeroout(sb->s_bdev,
947 block << (sb->s_blocksize_bits - 9),
948 nr_blocks << (sb->s_blocksize_bits - 9),
949 gfp_mask);
952 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
954 enum blk_default_limits {
955 BLK_MAX_SEGMENTS = 128,
956 BLK_SAFE_MAX_SECTORS = 255,
957 BLK_DEF_MAX_SECTORS = 1024,
958 BLK_MAX_SEGMENT_SIZE = 65536,
959 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
962 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
964 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
966 return q->limits.bounce_pfn;
969 static inline unsigned long queue_segment_boundary(struct request_queue *q)
971 return q->limits.seg_boundary_mask;
974 static inline unsigned int queue_max_sectors(struct request_queue *q)
976 return q->limits.max_sectors;
979 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
981 return q->limits.max_hw_sectors;
984 static inline unsigned short queue_max_segments(struct request_queue *q)
986 return q->limits.max_segments;
989 static inline unsigned int queue_max_segment_size(struct request_queue *q)
991 return q->limits.max_segment_size;
994 static inline unsigned short queue_logical_block_size(struct request_queue *q)
996 int retval = 512;
998 if (q && q->limits.logical_block_size)
999 retval = q->limits.logical_block_size;
1001 return retval;
1004 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1006 return queue_logical_block_size(bdev_get_queue(bdev));
1009 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1011 return q->limits.physical_block_size;
1014 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1016 return queue_physical_block_size(bdev_get_queue(bdev));
1019 static inline unsigned int queue_io_min(struct request_queue *q)
1021 return q->limits.io_min;
1024 static inline int bdev_io_min(struct block_device *bdev)
1026 return queue_io_min(bdev_get_queue(bdev));
1029 static inline unsigned int queue_io_opt(struct request_queue *q)
1031 return q->limits.io_opt;
1034 static inline int bdev_io_opt(struct block_device *bdev)
1036 return queue_io_opt(bdev_get_queue(bdev));
1039 static inline int queue_alignment_offset(struct request_queue *q)
1041 if (q->limits.misaligned)
1042 return -1;
1044 return q->limits.alignment_offset;
1047 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1049 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1050 unsigned int alignment = (sector << 9) & (granularity - 1);
1052 return (granularity + lim->alignment_offset - alignment)
1053 & (granularity - 1);
1056 static inline int bdev_alignment_offset(struct block_device *bdev)
1058 struct request_queue *q = bdev_get_queue(bdev);
1060 if (q->limits.misaligned)
1061 return -1;
1063 if (bdev != bdev->bd_contains)
1064 return bdev->bd_part->alignment_offset;
1066 return q->limits.alignment_offset;
1069 static inline int queue_discard_alignment(struct request_queue *q)
1071 if (q->limits.discard_misaligned)
1072 return -1;
1074 return q->limits.discard_alignment;
1077 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1079 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1081 if (!lim->max_discard_sectors)
1082 return 0;
1084 return (lim->discard_granularity + lim->discard_alignment - alignment)
1085 & (lim->discard_granularity - 1);
1088 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1090 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1091 return 1;
1093 return 0;
1096 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1098 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1101 static inline int queue_dma_alignment(struct request_queue *q)
1103 return q ? q->dma_alignment : 511;
1106 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1107 unsigned int len)
1109 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1110 return !(addr & alignment) && !(len & alignment);
1113 /* assumes size > 256 */
1114 static inline unsigned int blksize_bits(unsigned int size)
1116 unsigned int bits = 8;
1117 do {
1118 bits++;
1119 size >>= 1;
1120 } while (size > 256);
1121 return bits;
1124 static inline unsigned int block_size(struct block_device *bdev)
1126 return bdev->bd_block_size;
1129 static inline bool queue_flush_queueable(struct request_queue *q)
1131 return !q->flush_not_queueable;
1134 typedef struct {struct page *v;} Sector;
1136 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1138 static inline void put_dev_sector(Sector p)
1140 page_cache_release(p.v);
1143 struct work_struct;
1144 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1146 #ifdef CONFIG_BLK_CGROUP
1148 * This should not be using sched_clock(). A real patch is in progress
1149 * to fix this up, until that is in place we need to disable preemption
1150 * around sched_clock() in this function and set_io_start_time_ns().
1152 static inline void set_start_time_ns(struct request *req)
1154 preempt_disable();
1155 req->start_time_ns = sched_clock();
1156 preempt_enable();
1159 static inline void set_io_start_time_ns(struct request *req)
1161 preempt_disable();
1162 req->io_start_time_ns = sched_clock();
1163 preempt_enable();
1166 static inline uint64_t rq_start_time_ns(struct request *req)
1168 return req->start_time_ns;
1171 static inline uint64_t rq_io_start_time_ns(struct request *req)
1173 return req->io_start_time_ns;
1175 #else
1176 static inline void set_start_time_ns(struct request *req) {}
1177 static inline void set_io_start_time_ns(struct request *req) {}
1178 static inline uint64_t rq_start_time_ns(struct request *req)
1180 return 0;
1182 static inline uint64_t rq_io_start_time_ns(struct request *req)
1184 return 0;
1186 #endif
1188 #ifdef CONFIG_BLK_DEV_THROTTLING
1189 extern int blk_throtl_init(struct request_queue *q);
1190 extern void blk_throtl_exit(struct request_queue *q);
1191 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1192 #else /* CONFIG_BLK_DEV_THROTTLING */
1193 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1195 return 0;
1198 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1199 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1200 #endif /* CONFIG_BLK_DEV_THROTTLING */
1202 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1203 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1204 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1205 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1207 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1209 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1210 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1212 struct blk_integrity_exchg {
1213 void *prot_buf;
1214 void *data_buf;
1215 sector_t sector;
1216 unsigned int data_size;
1217 unsigned short sector_size;
1218 const char *disk_name;
1221 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1222 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1223 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1224 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1226 struct blk_integrity {
1227 integrity_gen_fn *generate_fn;
1228 integrity_vrfy_fn *verify_fn;
1229 integrity_set_tag_fn *set_tag_fn;
1230 integrity_get_tag_fn *get_tag_fn;
1232 unsigned short flags;
1233 unsigned short tuple_size;
1234 unsigned short sector_size;
1235 unsigned short tag_size;
1237 const char *name;
1239 struct kobject kobj;
1242 extern bool blk_integrity_is_initialized(struct gendisk *);
1243 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1244 extern void blk_integrity_unregister(struct gendisk *);
1245 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1246 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1247 struct scatterlist *);
1248 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1249 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1250 struct request *);
1251 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1252 struct bio *);
1254 static inline
1255 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1257 return bdev->bd_disk->integrity;
1260 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1262 return disk->integrity;
1265 static inline int blk_integrity_rq(struct request *rq)
1267 if (rq->bio == NULL)
1268 return 0;
1270 return bio_integrity(rq->bio);
1273 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1274 unsigned int segs)
1276 q->limits.max_integrity_segments = segs;
1279 static inline unsigned short
1280 queue_max_integrity_segments(struct request_queue *q)
1282 return q->limits.max_integrity_segments;
1285 #else /* CONFIG_BLK_DEV_INTEGRITY */
1287 #define blk_integrity_rq(rq) (0)
1288 #define blk_rq_count_integrity_sg(a, b) (0)
1289 #define blk_rq_map_integrity_sg(a, b, c) (0)
1290 #define bdev_get_integrity(a) (0)
1291 #define blk_get_integrity(a) (0)
1292 #define blk_integrity_compare(a, b) (0)
1293 #define blk_integrity_register(a, b) (0)
1294 #define blk_integrity_unregister(a) do { } while (0)
1295 #define blk_queue_max_integrity_segments(a, b) do { } while (0)
1296 #define queue_max_integrity_segments(a) (0)
1297 #define blk_integrity_merge_rq(a, b, c) (0)
1298 #define blk_integrity_merge_bio(a, b, c) (0)
1299 #define blk_integrity_is_initialized(a) (0)
1301 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1303 struct block_device_operations {
1304 int (*open) (struct block_device *, fmode_t);
1305 int (*release) (struct gendisk *, fmode_t);
1306 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1307 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1308 int (*direct_access) (struct block_device *, sector_t,
1309 void **, unsigned long *);
1310 unsigned int (*check_events) (struct gendisk *disk,
1311 unsigned int clearing);
1312 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1313 int (*media_changed) (struct gendisk *);
1314 void (*unlock_native_capacity) (struct gendisk *);
1315 int (*revalidate_disk) (struct gendisk *);
1316 int (*getgeo)(struct block_device *, struct hd_geometry *);
1317 /* this callback is with swap_lock and sometimes page table lock held */
1318 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1319 struct module *owner;
1322 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1323 unsigned long);
1324 #else /* CONFIG_BLOCK */
1326 * stubs for when the block layer is configured out
1328 #define buffer_heads_over_limit 0
1330 static inline long nr_blockdev_pages(void)
1332 return 0;
1335 struct blk_plug {
1338 static inline void blk_start_plug(struct blk_plug *plug)
1342 static inline void blk_finish_plug(struct blk_plug *plug)
1346 static inline void blk_flush_plug(struct task_struct *task)
1350 static inline void blk_schedule_flush_plug(struct task_struct *task)
1355 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1357 return false;
1360 #endif /* CONFIG_BLOCK */
1362 #endif