1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
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/module.h>
18 #include <linux/stringify.h>
19 #include <linux/gfp.h>
20 #include <linux/bsg.h>
21 #include <linux/smp.h>
23 #include <asm/scatterlist.h>
25 struct scsi_ioctl_command;
28 struct elevator_queue;
29 struct request_pm_state;
34 #define BLKDEV_MIN_RQ 4
35 #define BLKDEV_MAX_RQ 128 /* Default maximum */
38 typedef void (rq_end_io_fn)(struct request *, int);
42 * count[], starved[], and wait[] are indexed by
43 * BLK_RW_SYNC/BLK_RW_ASYNC
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,
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:rq_init()
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;
91 /* the following two fields are internal, NEVER access directly */
92 unsigned int __data_len; /* total data len */
93 sector_t __sector; /* sector cursor */
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.
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.
113 void *elevator_private;
114 void *elevator_private2;
115 void *elevator_private3;
117 struct gendisk *rq_disk;
118 unsigned long start_time;
119 #ifdef CONFIG_BLK_CGROUP
120 unsigned long long start_time_ns;
121 unsigned long long io_start_time_ns; /* when passed to hardware */
123 /* Number of scatter-gather DMA addr+len pairs after
124 * physical address coalescing is performed.
126 unsigned short nr_phys_segments;
128 unsigned short ioprio;
132 void *special; /* opaque pointer available for LLD use */
133 char *buffer; /* kaddr of the current segment if available */
139 * when request is used as a packet command carrier
141 unsigned char __cmd[BLK_MAX_CDB];
143 unsigned short cmd_len;
145 unsigned int extra_len; /* length of alignment and padding */
146 unsigned int sense_len;
147 unsigned int resid_len; /* residual count */
150 unsigned long deadline;
151 struct list_head timeout_list;
152 unsigned int timeout;
156 * completion callback.
158 rq_end_io_fn *end_io;
162 struct request *next_rq;
165 static inline unsigned short req_get_ioprio(struct request *req)
171 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
172 * requests. Some step values could eventually be made generic.
174 struct request_pm_state
176 /* PM state machine step value, currently driver specific */
178 /* requested PM state value (S1, S2, S3, S4, ...) */
180 void* data; /* for driver use */
183 #include <linux/elevator.h>
185 typedef void (request_fn_proc) (struct request_queue *q);
186 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
187 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
188 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
189 typedef void (unplug_fn) (struct request_queue *);
192 struct bvec_merge_data {
193 struct block_device *bi_bdev;
198 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
200 typedef void (softirq_done_fn)(struct request *);
201 typedef int (dma_drain_needed_fn)(struct request *);
202 typedef int (lld_busy_fn) (struct request_queue *q);
204 enum blk_eh_timer_return {
210 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
212 enum blk_queue_state {
217 struct blk_queue_tag {
218 struct request **tag_index; /* map of busy tags */
219 unsigned long *tag_map; /* bit map of free/busy tags */
220 int busy; /* current depth */
221 int max_depth; /* what we will send to device */
222 int real_max_depth; /* what the array can hold */
223 atomic_t refcnt; /* map can be shared */
226 #define BLK_SCSI_MAX_CMDS (256)
227 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
229 struct queue_limits {
230 unsigned long bounce_pfn;
231 unsigned long seg_boundary_mask;
233 unsigned int max_hw_sectors;
234 unsigned int max_sectors;
235 unsigned int max_segment_size;
236 unsigned int physical_block_size;
237 unsigned int alignment_offset;
240 unsigned int max_discard_sectors;
241 unsigned int discard_granularity;
242 unsigned int discard_alignment;
244 unsigned short logical_block_size;
245 unsigned short max_segments;
247 unsigned char misaligned;
248 unsigned char discard_misaligned;
249 unsigned char no_cluster;
250 signed char discard_zeroes_data;
256 * Together with queue_head for cacheline sharing
258 struct list_head queue_head;
259 struct request *last_merge;
260 struct elevator_queue *elevator;
263 * the queue request freelist, one for reads and one for writes
265 struct request_list rq;
267 request_fn_proc *request_fn;
268 make_request_fn *make_request_fn;
269 prep_rq_fn *prep_rq_fn;
270 unprep_rq_fn *unprep_rq_fn;
271 unplug_fn *unplug_fn;
272 merge_bvec_fn *merge_bvec_fn;
273 softirq_done_fn *softirq_done_fn;
274 rq_timed_out_fn *rq_timed_out_fn;
275 dma_drain_needed_fn *dma_drain_needed;
276 lld_busy_fn *lld_busy_fn;
279 * Dispatch queue sorting
282 struct request *boundary_rq;
285 * Auto-unplugging state
287 struct timer_list unplug_timer;
288 int unplug_thresh; /* After this many requests */
289 unsigned long unplug_delay; /* After this many jiffies */
290 struct work_struct unplug_work;
292 struct backing_dev_info backing_dev_info;
295 * The queue owner gets to use this for whatever they like.
296 * ll_rw_blk doesn't touch it.
301 * queue needs bounce pages for pages above this limit
306 * various queue flags, see QUEUE_* below
308 unsigned long queue_flags;
311 * protects queue structures from reentrancy. ->__queue_lock should
312 * _never_ be used directly, it is queue private. always use
315 spinlock_t __queue_lock;
316 spinlock_t *queue_lock;
326 unsigned long nr_requests; /* Max # of requests */
327 unsigned int nr_congestion_on;
328 unsigned int nr_congestion_off;
329 unsigned int nr_batching;
331 void *dma_drain_buffer;
332 unsigned int dma_drain_size;
333 unsigned int dma_pad_mask;
334 unsigned int dma_alignment;
336 struct blk_queue_tag *queue_tags;
337 struct list_head tag_busy_list;
339 unsigned int nr_sorted;
340 unsigned int in_flight[2];
342 unsigned int rq_timeout;
343 struct timer_list timeout;
344 struct list_head timeout_list;
346 struct queue_limits limits;
351 unsigned int sg_timeout;
352 unsigned int sg_reserved_size;
354 #ifdef CONFIG_BLK_DEV_IO_TRACE
355 struct blk_trace *blk_trace;
358 * for flush operations
360 unsigned int ordered, next_ordered;
361 unsigned int flush_flags;
362 unsigned int flush_seq;
364 struct request flush_rq;
365 struct request *orig_flush_rq;
366 struct list_head pending_flushes;
368 struct mutex sysfs_lock;
370 #if defined(CONFIG_BLK_DEV_BSG)
371 struct bsg_class_device bsg_dev;
375 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
376 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
377 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
378 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
379 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
380 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
381 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
382 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
383 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
384 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
385 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
386 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
387 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
388 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
389 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
390 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
391 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
392 #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */
393 #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */
394 #define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */
395 #define QUEUE_FLAG_SECDISCARD 19 /* supports SECDISCARD */
397 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
398 (1 << QUEUE_FLAG_CLUSTER) | \
399 (1 << QUEUE_FLAG_STACKABLE) | \
400 (1 << QUEUE_FLAG_SAME_COMP) | \
401 (1 << QUEUE_FLAG_ADD_RANDOM))
403 static inline int queue_is_locked(struct request_queue *q)
406 spinlock_t *lock = q->queue_lock;
407 return lock && spin_is_locked(lock);
413 static inline void queue_flag_set_unlocked(unsigned int flag,
414 struct request_queue *q)
416 __set_bit(flag, &q->queue_flags);
419 static inline int queue_flag_test_and_clear(unsigned int flag,
420 struct request_queue *q)
422 WARN_ON_ONCE(!queue_is_locked(q));
424 if (test_bit(flag, &q->queue_flags)) {
425 __clear_bit(flag, &q->queue_flags);
432 static inline int queue_flag_test_and_set(unsigned int flag,
433 struct request_queue *q)
435 WARN_ON_ONCE(!queue_is_locked(q));
437 if (!test_bit(flag, &q->queue_flags)) {
438 __set_bit(flag, &q->queue_flags);
445 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
447 WARN_ON_ONCE(!queue_is_locked(q));
448 __set_bit(flag, &q->queue_flags);
451 static inline void queue_flag_clear_unlocked(unsigned int flag,
452 struct request_queue *q)
454 __clear_bit(flag, &q->queue_flags);
457 static inline int queue_in_flight(struct request_queue *q)
459 return q->in_flight[0] + q->in_flight[1];
462 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
464 WARN_ON_ONCE(!queue_is_locked(q));
465 __clear_bit(flag, &q->queue_flags);
470 * Hardbarrier is supported with one of the following methods.
472 * NONE : hardbarrier unsupported
473 * DRAIN : ordering by draining is enough
474 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
475 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
477 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
478 QUEUE_ORDERED_DO_BAR = 0x20,
479 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
480 QUEUE_ORDERED_DO_FUA = 0x80,
482 QUEUE_ORDERED_NONE = 0x00,
484 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR,
485 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
486 QUEUE_ORDERED_DO_PREFLUSH |
487 QUEUE_ORDERED_DO_POSTFLUSH,
488 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
489 QUEUE_ORDERED_DO_PREFLUSH |
490 QUEUE_ORDERED_DO_FUA,
493 * FLUSH/FUA sequences.
495 QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
496 QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
497 QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
498 QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
499 QUEUE_FSEQ_DONE = (1 << 4),
502 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
503 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
504 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
505 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
506 #define blk_queue_noxmerges(q) \
507 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
508 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
509 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
510 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
511 #define blk_queue_stackable(q) \
512 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
513 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
514 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
515 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
517 #define blk_noretry_request(rq) \
518 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
519 REQ_FAILFAST_DRIVER))
521 #define blk_account_rq(rq) \
522 (((rq)->cmd_flags & REQ_STARTED) && \
523 ((rq)->cmd_type == REQ_TYPE_FS || \
524 ((rq)->cmd_flags & REQ_DISCARD)))
526 #define blk_pm_request(rq) \
527 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
528 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
530 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
531 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
532 /* rq->queuelist of dequeued request must be list_empty() */
533 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
535 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
537 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
540 * We regard a request as sync, if either a read or a sync write
542 static inline bool rw_is_sync(unsigned int rw_flags)
544 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
547 static inline bool rq_is_sync(struct request *rq)
549 return rw_is_sync(rq->cmd_flags);
552 static inline int blk_queue_full(struct request_queue *q, int sync)
555 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
556 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
559 static inline void blk_set_queue_full(struct request_queue *q, int sync)
562 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
564 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
567 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
570 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
572 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
577 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
578 * it already be started by driver.
580 #define RQ_NOMERGE_FLAGS \
581 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
582 #define rq_mergeable(rq) \
583 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
584 (((rq)->cmd_flags & REQ_DISCARD) || \
585 (rq)->cmd_type == REQ_TYPE_FS))
588 * q->prep_rq_fn return values
590 #define BLKPREP_OK 0 /* serve it */
591 #define BLKPREP_KILL 1 /* fatal error, kill */
592 #define BLKPREP_DEFER 2 /* leave on queue */
594 extern unsigned long blk_max_low_pfn, blk_max_pfn;
597 * standard bounce addresses:
599 * BLK_BOUNCE_HIGH : bounce all highmem pages
600 * BLK_BOUNCE_ANY : don't bounce anything
601 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
604 #if BITS_PER_LONG == 32
605 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
607 #define BLK_BOUNCE_HIGH -1ULL
609 #define BLK_BOUNCE_ANY (-1ULL)
610 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
613 * default timeout for SG_IO if none specified
615 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
616 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
619 extern int init_emergency_isa_pool(void);
620 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
622 static inline int init_emergency_isa_pool(void)
626 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
629 #endif /* CONFIG_MMU */
635 unsigned long offset;
640 struct req_iterator {
645 /* This should not be used directly - use rq_for_each_segment */
646 #define for_each_bio(_bio) \
647 for (; _bio; _bio = _bio->bi_next)
648 #define __rq_for_each_bio(_bio, rq) \
650 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
652 #define rq_for_each_segment(bvl, _rq, _iter) \
653 __rq_for_each_bio(_iter.bio, _rq) \
654 bio_for_each_segment(bvl, _iter.bio, _iter.i)
656 #define rq_iter_last(rq, _iter) \
657 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
659 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
660 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
662 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
663 extern void rq_flush_dcache_pages(struct request *rq);
665 static inline void rq_flush_dcache_pages(struct request *rq)
670 extern int blk_register_queue(struct gendisk *disk);
671 extern void blk_unregister_queue(struct gendisk *disk);
672 extern void register_disk(struct gendisk *dev);
673 extern void generic_make_request(struct bio *bio);
674 extern void blk_rq_init(struct request_queue *q, struct request *rq);
675 extern void blk_put_request(struct request *);
676 extern void __blk_put_request(struct request_queue *, struct request *);
677 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
678 extern struct request *blk_make_request(struct request_queue *, struct bio *,
680 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
681 extern void blk_requeue_request(struct request_queue *, struct request *);
682 extern void blk_add_request_payload(struct request *rq, struct page *page,
684 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
685 extern int blk_lld_busy(struct request_queue *q);
686 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
687 struct bio_set *bs, gfp_t gfp_mask,
688 int (*bio_ctr)(struct bio *, struct bio *, void *),
690 extern void blk_rq_unprep_clone(struct request *rq);
691 extern int blk_insert_cloned_request(struct request_queue *q,
693 extern void blk_plug_device(struct request_queue *);
694 extern void blk_plug_device_unlocked(struct request_queue *);
695 extern int blk_remove_plug(struct request_queue *);
696 extern void blk_recount_segments(struct request_queue *, struct bio *);
697 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
698 unsigned int, void __user *);
699 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
700 struct scsi_ioctl_command __user *);
703 * A queue has just exitted congestion. Note this in the global counter of
704 * congested queues, and wake up anyone who was waiting for requests to be
707 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
709 clear_bdi_congested(&q->backing_dev_info, sync);
713 * A queue has just entered congestion. Flag that in the queue's VM-visible
714 * state flags and increment the global gounter of congested queues.
716 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
718 set_bdi_congested(&q->backing_dev_info, sync);
721 extern void blk_start_queue(struct request_queue *q);
722 extern void blk_stop_queue(struct request_queue *q);
723 extern void blk_sync_queue(struct request_queue *q);
724 extern void __blk_stop_queue(struct request_queue *q);
725 extern void __blk_run_queue(struct request_queue *);
726 extern void blk_run_queue(struct request_queue *);
727 extern int blk_rq_map_user(struct request_queue *, struct request *,
728 struct rq_map_data *, void __user *, unsigned long,
730 extern int blk_rq_unmap_user(struct bio *);
731 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
732 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
733 struct rq_map_data *, struct sg_iovec *, int,
734 unsigned int, gfp_t);
735 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
736 struct request *, int);
737 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
738 struct request *, int, rq_end_io_fn *);
739 extern void blk_unplug(struct request_queue *q);
741 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
743 return bdev->bd_disk->queue;
747 * blk_rq_pos() : the current sector
748 * blk_rq_bytes() : bytes left in the entire request
749 * blk_rq_cur_bytes() : bytes left in the current segment
750 * blk_rq_err_bytes() : bytes left till the next error boundary
751 * blk_rq_sectors() : sectors left in the entire request
752 * blk_rq_cur_sectors() : sectors left in the current segment
754 static inline sector_t blk_rq_pos(const struct request *rq)
759 static inline unsigned int blk_rq_bytes(const struct request *rq)
761 return rq->__data_len;
764 static inline int blk_rq_cur_bytes(const struct request *rq)
766 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
769 extern unsigned int blk_rq_err_bytes(const struct request *rq);
771 static inline unsigned int blk_rq_sectors(const struct request *rq)
773 return blk_rq_bytes(rq) >> 9;
776 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
778 return blk_rq_cur_bytes(rq) >> 9;
782 * Request issue related functions.
784 extern struct request *blk_peek_request(struct request_queue *q);
785 extern void blk_start_request(struct request *rq);
786 extern struct request *blk_fetch_request(struct request_queue *q);
789 * Request completion related functions.
791 * blk_update_request() completes given number of bytes and updates
792 * the request without completing it.
794 * blk_end_request() and friends. __blk_end_request() must be called
795 * with the request queue spinlock acquired.
797 * Several drivers define their own end_request and call
798 * blk_end_request() for parts of the original function.
799 * This prevents code duplication in drivers.
801 extern bool blk_update_request(struct request *rq, int error,
802 unsigned int nr_bytes);
803 extern bool blk_end_request(struct request *rq, int error,
804 unsigned int nr_bytes);
805 extern void blk_end_request_all(struct request *rq, int error);
806 extern bool blk_end_request_cur(struct request *rq, int error);
807 extern bool blk_end_request_err(struct request *rq, int error);
808 extern bool __blk_end_request(struct request *rq, int error,
809 unsigned int nr_bytes);
810 extern void __blk_end_request_all(struct request *rq, int error);
811 extern bool __blk_end_request_cur(struct request *rq, int error);
812 extern bool __blk_end_request_err(struct request *rq, int error);
814 extern void blk_complete_request(struct request *);
815 extern void __blk_complete_request(struct request *);
816 extern void blk_abort_request(struct request *);
817 extern void blk_abort_queue(struct request_queue *);
818 extern void blk_unprep_request(struct request *);
821 * Access functions for manipulating queue properties
823 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
824 spinlock_t *lock, int node_id);
825 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
827 spinlock_t *, int node_id);
828 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
829 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
830 request_fn_proc *, spinlock_t *);
831 extern void blk_cleanup_queue(struct request_queue *);
832 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
833 extern void blk_queue_bounce_limit(struct request_queue *, u64);
834 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
835 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
836 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
837 extern void blk_queue_max_discard_sectors(struct request_queue *q,
838 unsigned int max_discard_sectors);
839 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
840 extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
841 extern void blk_queue_alignment_offset(struct request_queue *q,
842 unsigned int alignment);
843 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
844 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
845 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
846 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
847 extern void blk_set_default_limits(struct queue_limits *lim);
848 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
850 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
852 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
854 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
855 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
856 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
857 extern int blk_queue_dma_drain(struct request_queue *q,
858 dma_drain_needed_fn *dma_drain_needed,
859 void *buf, unsigned int size);
860 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
861 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
862 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
863 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
864 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
865 extern void blk_queue_dma_alignment(struct request_queue *, int);
866 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
867 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
868 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
869 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
870 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
871 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
873 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
874 extern void blk_dump_rq_flags(struct request *, char *);
875 extern void generic_unplug_device(struct request_queue *);
876 extern long nr_blockdev_pages(void);
878 int blk_get_queue(struct request_queue *);
879 struct request_queue *blk_alloc_queue(gfp_t);
880 struct request_queue *blk_alloc_queue_node(gfp_t, int);
881 extern void blk_put_queue(struct request_queue *);
886 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
887 extern int blk_queue_start_tag(struct request_queue *, struct request *);
888 extern struct request *blk_queue_find_tag(struct request_queue *, int);
889 extern void blk_queue_end_tag(struct request_queue *, struct request *);
890 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
891 extern void blk_queue_free_tags(struct request_queue *);
892 extern int blk_queue_resize_tags(struct request_queue *, int);
893 extern void blk_queue_invalidate_tags(struct request_queue *);
894 extern struct blk_queue_tag *blk_init_tags(int);
895 extern void blk_free_tags(struct blk_queue_tag *);
897 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
900 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
902 return bqt->tag_index[tag];
905 BLKDEV_WAIT, /* wait for completion */
906 BLKDEV_BARRIER, /* issue request with barrier */
907 BLKDEV_SECURE, /* secure discard */
909 #define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
910 #define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER)
911 #define BLKDEV_IFL_SECURE (1 << BLKDEV_SECURE)
912 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
914 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
915 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
916 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
917 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
918 static inline int sb_issue_discard(struct super_block *sb,
919 sector_t block, sector_t nr_blocks)
921 block <<= (sb->s_blocksize_bits - 9);
922 nr_blocks <<= (sb->s_blocksize_bits - 9);
923 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS,
924 BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
927 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
929 enum blk_default_limits {
930 BLK_MAX_SEGMENTS = 128,
931 BLK_SAFE_MAX_SECTORS = 255,
932 BLK_DEF_MAX_SECTORS = 1024,
933 BLK_MAX_SEGMENT_SIZE = 65536,
934 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
937 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
939 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
941 return q->limits.bounce_pfn;
944 static inline unsigned long queue_segment_boundary(struct request_queue *q)
946 return q->limits.seg_boundary_mask;
949 static inline unsigned int queue_max_sectors(struct request_queue *q)
951 return q->limits.max_sectors;
954 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
956 return q->limits.max_hw_sectors;
959 static inline unsigned short queue_max_segments(struct request_queue *q)
961 return q->limits.max_segments;
964 static inline unsigned int queue_max_segment_size(struct request_queue *q)
966 return q->limits.max_segment_size;
969 static inline unsigned short queue_logical_block_size(struct request_queue *q)
973 if (q && q->limits.logical_block_size)
974 retval = q->limits.logical_block_size;
979 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
981 return queue_logical_block_size(bdev_get_queue(bdev));
984 static inline unsigned int queue_physical_block_size(struct request_queue *q)
986 return q->limits.physical_block_size;
989 static inline int bdev_physical_block_size(struct block_device *bdev)
991 return queue_physical_block_size(bdev_get_queue(bdev));
994 static inline unsigned int queue_io_min(struct request_queue *q)
996 return q->limits.io_min;
999 static inline int bdev_io_min(struct block_device *bdev)
1001 return queue_io_min(bdev_get_queue(bdev));
1004 static inline unsigned int queue_io_opt(struct request_queue *q)
1006 return q->limits.io_opt;
1009 static inline int bdev_io_opt(struct block_device *bdev)
1011 return queue_io_opt(bdev_get_queue(bdev));
1014 static inline int queue_alignment_offset(struct request_queue *q)
1016 if (q->limits.misaligned)
1019 return q->limits.alignment_offset;
1022 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1024 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1025 unsigned int alignment = (sector << 9) & (granularity - 1);
1027 return (granularity + lim->alignment_offset - alignment)
1028 & (granularity - 1);
1031 static inline int bdev_alignment_offset(struct block_device *bdev)
1033 struct request_queue *q = bdev_get_queue(bdev);
1035 if (q->limits.misaligned)
1038 if (bdev != bdev->bd_contains)
1039 return bdev->bd_part->alignment_offset;
1041 return q->limits.alignment_offset;
1044 static inline int queue_discard_alignment(struct request_queue *q)
1046 if (q->limits.discard_misaligned)
1049 return q->limits.discard_alignment;
1052 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1054 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1056 return (lim->discard_granularity + lim->discard_alignment - alignment)
1057 & (lim->discard_granularity - 1);
1060 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1062 if (q->limits.discard_zeroes_data == 1)
1068 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1070 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1073 static inline int queue_dma_alignment(struct request_queue *q)
1075 return q ? q->dma_alignment : 511;
1078 static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1081 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1082 return !((unsigned long)addr & alignment) && !(len & alignment);
1085 /* assumes size > 256 */
1086 static inline unsigned int blksize_bits(unsigned int size)
1088 unsigned int bits = 8;
1092 } while (size > 256);
1096 static inline unsigned int block_size(struct block_device *bdev)
1098 return bdev->bd_block_size;
1101 typedef struct {struct page *v;} Sector;
1103 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1105 static inline void put_dev_sector(Sector p)
1107 page_cache_release(p.v);
1111 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1113 #ifdef CONFIG_BLK_CGROUP
1115 * This should not be using sched_clock(). A real patch is in progress
1116 * to fix this up, until that is in place we need to disable preemption
1117 * around sched_clock() in this function and set_io_start_time_ns().
1119 static inline void set_start_time_ns(struct request *req)
1122 req->start_time_ns = sched_clock();
1126 static inline void set_io_start_time_ns(struct request *req)
1129 req->io_start_time_ns = sched_clock();
1133 static inline uint64_t rq_start_time_ns(struct request *req)
1135 return req->start_time_ns;
1138 static inline uint64_t rq_io_start_time_ns(struct request *req)
1140 return req->io_start_time_ns;
1143 static inline void set_start_time_ns(struct request *req) {}
1144 static inline void set_io_start_time_ns(struct request *req) {}
1145 static inline uint64_t rq_start_time_ns(struct request *req)
1149 static inline uint64_t rq_io_start_time_ns(struct request *req)
1155 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1156 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1157 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1158 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1160 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1162 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1163 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1165 struct blk_integrity_exchg {
1169 unsigned int data_size;
1170 unsigned short sector_size;
1171 const char *disk_name;
1174 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1175 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1176 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1177 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1179 struct blk_integrity {
1180 integrity_gen_fn *generate_fn;
1181 integrity_vrfy_fn *verify_fn;
1182 integrity_set_tag_fn *set_tag_fn;
1183 integrity_get_tag_fn *get_tag_fn;
1185 unsigned short flags;
1186 unsigned short tuple_size;
1187 unsigned short sector_size;
1188 unsigned short tag_size;
1192 struct kobject kobj;
1195 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1196 extern void blk_integrity_unregister(struct gendisk *);
1197 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1198 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1199 extern int blk_rq_count_integrity_sg(struct request *);
1202 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1204 return bdev->bd_disk->integrity;
1207 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1209 return disk->integrity;
1212 static inline int blk_integrity_rq(struct request *rq)
1214 if (rq->bio == NULL)
1217 return bio_integrity(rq->bio);
1220 #else /* CONFIG_BLK_DEV_INTEGRITY */
1222 #define blk_integrity_rq(rq) (0)
1223 #define blk_rq_count_integrity_sg(a) (0)
1224 #define blk_rq_map_integrity_sg(a, b) (0)
1225 #define bdev_get_integrity(a) (0)
1226 #define blk_get_integrity(a) (0)
1227 #define blk_integrity_compare(a, b) (0)
1228 #define blk_integrity_register(a, b) (0)
1229 #define blk_integrity_unregister(a) do { } while (0);
1231 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1233 struct block_device_operations {
1234 int (*open) (struct block_device *, fmode_t);
1235 int (*release) (struct gendisk *, fmode_t);
1236 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1237 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1238 int (*direct_access) (struct block_device *, sector_t,
1239 void **, unsigned long *);
1240 int (*media_changed) (struct gendisk *);
1241 void (*unlock_native_capacity) (struct gendisk *);
1242 int (*revalidate_disk) (struct gendisk *);
1243 int (*getgeo)(struct block_device *, struct hd_geometry *);
1244 /* this callback is with swap_lock and sometimes page table lock held */
1245 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1246 struct module *owner;
1249 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1251 #else /* CONFIG_BLOCK */
1253 * stubs for when the block layer is configured out
1255 #define buffer_heads_over_limit 0
1257 static inline long nr_blockdev_pages(void)
1262 #endif /* CONFIG_BLOCK */