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;
35 #define BLKDEV_MIN_RQ 4
36 #define BLKDEV_MAX_RQ 128 /* Default maximum */
39 typedef void (rq_end_io_fn)(struct request *, int);
43 * count[], starved[], and wait[] are indexed by
44 * BLK_RW_SYNC/BLK_RW_ASYNC
50 wait_queue_head_t wait[2];
54 * request command types
56 enum rq_cmd_type_bits {
57 REQ_TYPE_FS = 1, /* fs request */
58 REQ_TYPE_BLOCK_PC, /* scsi command */
59 REQ_TYPE_SENSE, /* sense request */
60 REQ_TYPE_PM_SUSPEND, /* suspend request */
61 REQ_TYPE_PM_RESUME, /* resume request */
62 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
63 REQ_TYPE_SPECIAL, /* driver defined type */
65 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 * private REQ_LB opcodes to differentiate what type of request this is
69 REQ_TYPE_ATA_TASKFILE,
73 #define BLK_MAX_CDB 16
76 * try to put the fields that are referenced together in the same cacheline.
77 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
81 struct list_head queuelist;
82 struct call_single_data csd;
84 struct request_queue *q;
86 unsigned int cmd_flags;
87 enum rq_cmd_type_bits cmd_type;
88 unsigned long atomic_flags;
92 /* the following two fields are internal, NEVER access directly */
93 unsigned int __data_len; /* total data len */
94 sector_t __sector; /* sector cursor */
99 struct hlist_node hash; /* merge hash */
101 * The rb_node is only used inside the io scheduler, requests
102 * are pruned when moved to the dispatch queue. So let the
103 * completion_data share space with the rb_node.
106 struct rb_node rb_node; /* sort/lookup */
107 void *completion_data;
111 * Three pointers are available for the IO schedulers, if they need
112 * more they have to dynamically allocate it. Flush requests are
113 * never put on the IO scheduler. So let the flush fields share
114 * space with the three elevator_private pointers.
117 void *elevator_private[3];
120 struct list_head list;
121 rq_end_io_fn *saved_end_io;
125 struct gendisk *rq_disk;
126 struct hd_struct *part;
127 unsigned long start_time;
128 #ifdef CONFIG_BLK_CGROUP
129 unsigned long long start_time_ns;
130 unsigned long long io_start_time_ns; /* when passed to hardware */
132 /* Number of scatter-gather DMA addr+len pairs after
133 * physical address coalescing is performed.
135 unsigned short nr_phys_segments;
136 #if defined(CONFIG_BLK_DEV_INTEGRITY)
137 unsigned short nr_integrity_segments;
140 unsigned short ioprio;
144 void *special; /* opaque pointer available for LLD use */
145 char *buffer; /* kaddr of the current segment if available */
151 * when request is used as a packet command carrier
153 unsigned char __cmd[BLK_MAX_CDB];
155 unsigned short cmd_len;
157 unsigned int extra_len; /* length of alignment and padding */
158 unsigned int sense_len;
159 unsigned int resid_len; /* residual count */
162 unsigned long deadline;
163 struct list_head timeout_list;
164 unsigned int timeout;
168 * completion callback.
170 rq_end_io_fn *end_io;
174 struct request *next_rq;
177 static inline unsigned short req_get_ioprio(struct request *req)
183 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
184 * requests. Some step values could eventually be made generic.
186 struct request_pm_state
188 /* PM state machine step value, currently driver specific */
190 /* requested PM state value (S1, S2, S3, S4, ...) */
192 void* data; /* for driver use */
195 #include <linux/elevator.h>
197 typedef void (request_fn_proc) (struct request_queue *q);
198 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
199 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
200 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
203 struct bvec_merge_data {
204 struct block_device *bi_bdev;
209 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
211 typedef void (softirq_done_fn)(struct request *);
212 typedef int (dma_drain_needed_fn)(struct request *);
213 typedef int (lld_busy_fn) (struct request_queue *q);
214 typedef int (bsg_job_fn) (struct bsg_job *);
216 enum blk_eh_timer_return {
222 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
224 enum blk_queue_state {
229 struct blk_queue_tag {
230 struct request **tag_index; /* map of busy tags */
231 unsigned long *tag_map; /* bit map of free/busy tags */
232 int busy; /* current depth */
233 int max_depth; /* what we will send to device */
234 int real_max_depth; /* what the array can hold */
235 atomic_t refcnt; /* map can be shared */
238 #define BLK_SCSI_MAX_CMDS (256)
239 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
241 struct queue_limits {
242 unsigned long bounce_pfn;
243 unsigned long seg_boundary_mask;
245 unsigned int max_hw_sectors;
246 unsigned int max_sectors;
247 unsigned int max_segment_size;
248 unsigned int physical_block_size;
249 unsigned int alignment_offset;
252 unsigned int max_discard_sectors;
253 unsigned int discard_granularity;
254 unsigned int discard_alignment;
256 unsigned short logical_block_size;
257 unsigned short max_segments;
258 unsigned short max_integrity_segments;
260 unsigned char misaligned;
261 unsigned char discard_misaligned;
262 unsigned char cluster;
263 unsigned char discard_zeroes_data;
266 struct request_queue {
268 * Together with queue_head for cacheline sharing
270 struct list_head queue_head;
271 struct request *last_merge;
272 struct elevator_queue *elevator;
275 * the queue request freelist, one for reads and one for writes
277 struct request_list rq;
279 request_fn_proc *request_fn;
280 make_request_fn *make_request_fn;
281 prep_rq_fn *prep_rq_fn;
282 unprep_rq_fn *unprep_rq_fn;
283 merge_bvec_fn *merge_bvec_fn;
284 softirq_done_fn *softirq_done_fn;
285 rq_timed_out_fn *rq_timed_out_fn;
286 dma_drain_needed_fn *dma_drain_needed;
287 lld_busy_fn *lld_busy_fn;
290 * Dispatch queue sorting
293 struct request *boundary_rq;
296 * Delayed queue handling
298 struct delayed_work delay_work;
300 struct backing_dev_info backing_dev_info;
303 * The queue owner gets to use this for whatever they like.
304 * ll_rw_blk doesn't touch it.
309 * various queue flags, see QUEUE_* below
311 unsigned long queue_flags;
314 * queue needs bounce pages for pages above this limit
319 * protects queue structures from reentrancy. ->__queue_lock should
320 * _never_ be used directly, it is queue private. always use
323 spinlock_t __queue_lock;
324 spinlock_t *queue_lock;
334 unsigned long nr_requests; /* Max # of requests */
335 unsigned int nr_congestion_on;
336 unsigned int nr_congestion_off;
337 unsigned int nr_batching;
339 unsigned int dma_drain_size;
340 void *dma_drain_buffer;
341 unsigned int dma_pad_mask;
342 unsigned int dma_alignment;
344 struct blk_queue_tag *queue_tags;
345 struct list_head tag_busy_list;
347 unsigned int nr_sorted;
348 unsigned int in_flight[2];
350 unsigned int rq_timeout;
351 struct timer_list timeout;
352 struct list_head timeout_list;
354 struct queue_limits limits;
359 unsigned int sg_timeout;
360 unsigned int sg_reserved_size;
362 #ifdef CONFIG_BLK_DEV_IO_TRACE
363 struct blk_trace *blk_trace;
366 * for flush operations
368 unsigned int flush_flags;
369 unsigned int flush_not_queueable:1;
370 unsigned int flush_queue_delayed:1;
371 unsigned int flush_pending_idx:1;
372 unsigned int flush_running_idx:1;
373 unsigned long flush_pending_since;
374 struct list_head flush_queue[2];
375 struct list_head flush_data_in_flight;
376 struct request flush_rq;
378 struct mutex sysfs_lock;
380 #if defined(CONFIG_BLK_DEV_BSG)
381 bsg_job_fn *bsg_job_fn;
383 struct bsg_class_device bsg_dev;
386 #ifdef CONFIG_BLK_DEV_THROTTLING
388 struct throtl_data *td;
392 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
393 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
394 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
395 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
396 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
397 #define QUEUE_FLAG_ELVSWITCH 6 /* don't use elevator, just do FIFO */
398 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
399 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
400 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
401 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
402 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
403 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
404 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
405 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
406 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
407 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
408 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
409 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
410 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
412 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
413 (1 << QUEUE_FLAG_STACKABLE) | \
414 (1 << QUEUE_FLAG_SAME_COMP) | \
415 (1 << QUEUE_FLAG_ADD_RANDOM))
417 static inline int queue_is_locked(struct request_queue *q)
420 spinlock_t *lock = q->queue_lock;
421 return lock && spin_is_locked(lock);
427 static inline void queue_flag_set_unlocked(unsigned int flag,
428 struct request_queue *q)
430 __set_bit(flag, &q->queue_flags);
433 static inline int queue_flag_test_and_clear(unsigned int flag,
434 struct request_queue *q)
436 WARN_ON_ONCE(!queue_is_locked(q));
438 if (test_bit(flag, &q->queue_flags)) {
439 __clear_bit(flag, &q->queue_flags);
446 static inline int queue_flag_test_and_set(unsigned int flag,
447 struct request_queue *q)
449 WARN_ON_ONCE(!queue_is_locked(q));
451 if (!test_bit(flag, &q->queue_flags)) {
452 __set_bit(flag, &q->queue_flags);
459 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
461 WARN_ON_ONCE(!queue_is_locked(q));
462 __set_bit(flag, &q->queue_flags);
465 static inline void queue_flag_clear_unlocked(unsigned int flag,
466 struct request_queue *q)
468 __clear_bit(flag, &q->queue_flags);
471 static inline int queue_in_flight(struct request_queue *q)
473 return q->in_flight[0] + q->in_flight[1];
476 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
478 WARN_ON_ONCE(!queue_is_locked(q));
479 __clear_bit(flag, &q->queue_flags);
482 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
483 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
484 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
485 #define blk_queue_noxmerges(q) \
486 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
487 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
488 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
489 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
490 #define blk_queue_stackable(q) \
491 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
492 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
493 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
494 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
496 #define blk_noretry_request(rq) \
497 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
498 REQ_FAILFAST_DRIVER))
500 #define blk_account_rq(rq) \
501 (((rq)->cmd_flags & REQ_STARTED) && \
502 ((rq)->cmd_type == REQ_TYPE_FS || \
503 ((rq)->cmd_flags & REQ_DISCARD)))
505 #define blk_pm_request(rq) \
506 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
507 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
509 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
510 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
511 /* rq->queuelist of dequeued request must be list_empty() */
512 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
514 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
516 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
518 static inline unsigned int blk_queue_cluster(struct request_queue *q)
520 return q->limits.cluster;
524 * We regard a request as sync, if either a read or a sync write
526 static inline bool rw_is_sync(unsigned int rw_flags)
528 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
531 static inline bool rq_is_sync(struct request *rq)
533 return rw_is_sync(rq->cmd_flags);
536 static inline int blk_queue_full(struct request_queue *q, int sync)
539 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
540 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
543 static inline void blk_set_queue_full(struct request_queue *q, int sync)
546 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
548 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
551 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
554 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
556 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
561 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
562 * it already be started by driver.
564 #define RQ_NOMERGE_FLAGS \
565 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
566 #define rq_mergeable(rq) \
567 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
568 (((rq)->cmd_flags & REQ_DISCARD) || \
569 (rq)->cmd_type == REQ_TYPE_FS))
572 * q->prep_rq_fn return values
574 #define BLKPREP_OK 0 /* serve it */
575 #define BLKPREP_KILL 1 /* fatal error, kill */
576 #define BLKPREP_DEFER 2 /* leave on queue */
578 extern unsigned long blk_max_low_pfn, blk_max_pfn;
581 * standard bounce addresses:
583 * BLK_BOUNCE_HIGH : bounce all highmem pages
584 * BLK_BOUNCE_ANY : don't bounce anything
585 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
588 #if BITS_PER_LONG == 32
589 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
591 #define BLK_BOUNCE_HIGH -1ULL
593 #define BLK_BOUNCE_ANY (-1ULL)
594 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
597 * default timeout for SG_IO if none specified
599 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
600 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
603 extern int init_emergency_isa_pool(void);
604 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
606 static inline int init_emergency_isa_pool(void)
610 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
613 #endif /* CONFIG_MMU */
619 unsigned long offset;
624 struct req_iterator {
629 /* This should not be used directly - use rq_for_each_segment */
630 #define for_each_bio(_bio) \
631 for (; _bio; _bio = _bio->bi_next)
632 #define __rq_for_each_bio(_bio, rq) \
634 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
636 #define rq_for_each_segment(bvl, _rq, _iter) \
637 __rq_for_each_bio(_iter.bio, _rq) \
638 bio_for_each_segment(bvl, _iter.bio, _iter.i)
640 #define rq_iter_last(rq, _iter) \
641 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
643 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
644 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
646 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
647 extern void rq_flush_dcache_pages(struct request *rq);
649 static inline void rq_flush_dcache_pages(struct request *rq)
654 extern int blk_register_queue(struct gendisk *disk);
655 extern void blk_unregister_queue(struct gendisk *disk);
656 extern void generic_make_request(struct bio *bio);
657 extern void blk_rq_init(struct request_queue *q, struct request *rq);
658 extern void blk_put_request(struct request *);
659 extern void __blk_put_request(struct request_queue *, struct request *);
660 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
661 extern struct request *blk_make_request(struct request_queue *, struct bio *,
663 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
664 extern void blk_requeue_request(struct request_queue *, struct request *);
665 extern void blk_add_request_payload(struct request *rq, struct page *page,
667 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
668 extern int blk_lld_busy(struct request_queue *q);
669 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
670 struct bio_set *bs, gfp_t gfp_mask,
671 int (*bio_ctr)(struct bio *, struct bio *, void *),
673 extern void blk_rq_unprep_clone(struct request *rq);
674 extern int blk_insert_cloned_request(struct request_queue *q,
676 extern void blk_delay_queue(struct request_queue *, unsigned long);
677 extern void blk_recount_segments(struct request_queue *, struct bio *);
678 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
679 unsigned int, void __user *);
680 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
681 struct scsi_ioctl_command __user *);
684 * A queue has just exitted congestion. Note this in the global counter of
685 * congested queues, and wake up anyone who was waiting for requests to be
688 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
690 clear_bdi_congested(&q->backing_dev_info, sync);
694 * A queue has just entered congestion. Flag that in the queue's VM-visible
695 * state flags and increment the global gounter of congested queues.
697 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
699 set_bdi_congested(&q->backing_dev_info, sync);
702 extern void blk_start_queue(struct request_queue *q);
703 extern void blk_stop_queue(struct request_queue *q);
704 extern void blk_sync_queue(struct request_queue *q);
705 extern void __blk_stop_queue(struct request_queue *q);
706 extern void __blk_run_queue(struct request_queue *q);
707 extern void blk_run_queue(struct request_queue *);
708 extern void blk_run_queue_async(struct request_queue *q);
709 extern int blk_rq_map_user(struct request_queue *, struct request *,
710 struct rq_map_data *, void __user *, unsigned long,
712 extern int blk_rq_unmap_user(struct bio *);
713 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
714 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
715 struct rq_map_data *, struct sg_iovec *, int,
716 unsigned int, gfp_t);
717 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
718 struct request *, int);
719 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
720 struct request *, int, rq_end_io_fn *);
722 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
724 return bdev->bd_disk->queue;
728 * blk_rq_pos() : the current sector
729 * blk_rq_bytes() : bytes left in the entire request
730 * blk_rq_cur_bytes() : bytes left in the current segment
731 * blk_rq_err_bytes() : bytes left till the next error boundary
732 * blk_rq_sectors() : sectors left in the entire request
733 * blk_rq_cur_sectors() : sectors left in the current segment
735 static inline sector_t blk_rq_pos(const struct request *rq)
740 static inline unsigned int blk_rq_bytes(const struct request *rq)
742 return rq->__data_len;
745 static inline int blk_rq_cur_bytes(const struct request *rq)
747 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
750 extern unsigned int blk_rq_err_bytes(const struct request *rq);
752 static inline unsigned int blk_rq_sectors(const struct request *rq)
754 return blk_rq_bytes(rq) >> 9;
757 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
759 return blk_rq_cur_bytes(rq) >> 9;
763 * Request issue related functions.
765 extern struct request *blk_peek_request(struct request_queue *q);
766 extern void blk_start_request(struct request *rq);
767 extern struct request *blk_fetch_request(struct request_queue *q);
770 * Request completion related functions.
772 * blk_update_request() completes given number of bytes and updates
773 * the request without completing it.
775 * blk_end_request() and friends. __blk_end_request() must be called
776 * with the request queue spinlock acquired.
778 * Several drivers define their own end_request and call
779 * blk_end_request() for parts of the original function.
780 * This prevents code duplication in drivers.
782 extern bool blk_update_request(struct request *rq, int error,
783 unsigned int nr_bytes);
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);
789 extern bool __blk_end_request(struct request *rq, int error,
790 unsigned int nr_bytes);
791 extern void __blk_end_request_all(struct request *rq, int error);
792 extern bool __blk_end_request_cur(struct request *rq, int error);
793 extern bool __blk_end_request_err(struct request *rq, int error);
795 extern void blk_complete_request(struct request *);
796 extern void __blk_complete_request(struct request *);
797 extern void blk_abort_request(struct request *);
798 extern void blk_abort_queue(struct request_queue *);
799 extern void blk_unprep_request(struct request *);
802 * Access functions for manipulating queue properties
804 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
805 spinlock_t *lock, int node_id);
806 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
808 spinlock_t *, int node_id);
809 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
810 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
811 request_fn_proc *, spinlock_t *);
812 extern void blk_cleanup_queue(struct request_queue *);
813 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
814 extern void blk_queue_bounce_limit(struct request_queue *, u64);
815 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
816 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
817 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
818 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
819 extern void blk_queue_max_discard_sectors(struct request_queue *q,
820 unsigned int max_discard_sectors);
821 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
822 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
823 extern void blk_queue_alignment_offset(struct request_queue *q,
824 unsigned int alignment);
825 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
826 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
827 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
828 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
829 extern void blk_set_default_limits(struct queue_limits *lim);
830 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
832 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
834 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
836 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
837 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
838 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
839 extern int blk_queue_dma_drain(struct request_queue *q,
840 dma_drain_needed_fn *dma_drain_needed,
841 void *buf, unsigned int size);
842 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
843 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
844 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
845 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
846 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
847 extern void blk_queue_dma_alignment(struct request_queue *, int);
848 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
849 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
850 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
851 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
852 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
853 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
854 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
856 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
857 extern void blk_dump_rq_flags(struct request *, char *);
858 extern long nr_blockdev_pages(void);
860 int blk_get_queue(struct request_queue *);
861 struct request_queue *blk_alloc_queue(gfp_t);
862 struct request_queue *blk_alloc_queue_node(gfp_t, int);
863 extern void blk_put_queue(struct request_queue *);
866 * Note: Code in between changing the blk_plug list/cb_list or element of such
867 * lists is preemptable, but such code can't do sleep (or be very careful),
868 * otherwise data is corrupted. For details, please check schedule() where
869 * blk_schedule_flush_plug() is called.
873 struct list_head list;
874 struct list_head cb_list;
875 unsigned int should_sort;
878 #define BLK_MAX_REQUEST_COUNT 16
881 struct list_head list;
882 void (*callback)(struct blk_plug_cb *);
885 extern void blk_start_plug(struct blk_plug *);
886 extern void blk_finish_plug(struct blk_plug *);
887 extern void blk_flush_plug_list(struct blk_plug *, bool);
889 static inline void blk_flush_plug(struct task_struct *tsk)
891 struct blk_plug *plug = tsk->plug;
894 blk_flush_plug_list(plug, false);
897 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
899 struct blk_plug *plug = tsk->plug;
902 blk_flush_plug_list(plug, true);
905 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
907 struct blk_plug *plug = tsk->plug;
909 return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
915 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
916 extern int blk_queue_start_tag(struct request_queue *, struct request *);
917 extern struct request *blk_queue_find_tag(struct request_queue *, int);
918 extern void blk_queue_end_tag(struct request_queue *, struct request *);
919 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
920 extern void blk_queue_free_tags(struct request_queue *);
921 extern int blk_queue_resize_tags(struct request_queue *, int);
922 extern void blk_queue_invalidate_tags(struct request_queue *);
923 extern struct blk_queue_tag *blk_init_tags(int);
924 extern void blk_free_tags(struct blk_queue_tag *);
926 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
929 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
931 return bqt->tag_index[tag];
934 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
936 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
937 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
938 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
939 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
940 sector_t nr_sects, gfp_t gfp_mask);
941 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
942 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
944 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
945 nr_blocks << (sb->s_blocksize_bits - 9),
948 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
949 sector_t nr_blocks, gfp_t gfp_mask)
951 return blkdev_issue_zeroout(sb->s_bdev,
952 block << (sb->s_blocksize_bits - 9),
953 nr_blocks << (sb->s_blocksize_bits - 9),
957 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
959 enum blk_default_limits {
960 BLK_MAX_SEGMENTS = 128,
961 BLK_SAFE_MAX_SECTORS = 255,
962 BLK_DEF_MAX_SECTORS = 1024,
963 BLK_MAX_SEGMENT_SIZE = 65536,
964 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
967 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
969 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
971 return q->limits.bounce_pfn;
974 static inline unsigned long queue_segment_boundary(struct request_queue *q)
976 return q->limits.seg_boundary_mask;
979 static inline unsigned int queue_max_sectors(struct request_queue *q)
981 return q->limits.max_sectors;
984 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
986 return q->limits.max_hw_sectors;
989 static inline unsigned short queue_max_segments(struct request_queue *q)
991 return q->limits.max_segments;
994 static inline unsigned int queue_max_segment_size(struct request_queue *q)
996 return q->limits.max_segment_size;
999 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1003 if (q && q->limits.logical_block_size)
1004 retval = q->limits.logical_block_size;
1009 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1011 return queue_logical_block_size(bdev_get_queue(bdev));
1014 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1016 return q->limits.physical_block_size;
1019 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1021 return queue_physical_block_size(bdev_get_queue(bdev));
1024 static inline unsigned int queue_io_min(struct request_queue *q)
1026 return q->limits.io_min;
1029 static inline int bdev_io_min(struct block_device *bdev)
1031 return queue_io_min(bdev_get_queue(bdev));
1034 static inline unsigned int queue_io_opt(struct request_queue *q)
1036 return q->limits.io_opt;
1039 static inline int bdev_io_opt(struct block_device *bdev)
1041 return queue_io_opt(bdev_get_queue(bdev));
1044 static inline int queue_alignment_offset(struct request_queue *q)
1046 if (q->limits.misaligned)
1049 return q->limits.alignment_offset;
1052 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1054 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1055 unsigned int alignment = (sector << 9) & (granularity - 1);
1057 return (granularity + lim->alignment_offset - alignment)
1058 & (granularity - 1);
1061 static inline int bdev_alignment_offset(struct block_device *bdev)
1063 struct request_queue *q = bdev_get_queue(bdev);
1065 if (q->limits.misaligned)
1068 if (bdev != bdev->bd_contains)
1069 return bdev->bd_part->alignment_offset;
1071 return q->limits.alignment_offset;
1074 static inline int queue_discard_alignment(struct request_queue *q)
1076 if (q->limits.discard_misaligned)
1079 return q->limits.discard_alignment;
1082 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1084 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1086 if (!lim->max_discard_sectors)
1089 return (lim->discard_granularity + lim->discard_alignment - alignment)
1090 & (lim->discard_granularity - 1);
1093 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1095 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1101 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1103 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1106 static inline int queue_dma_alignment(struct request_queue *q)
1108 return q ? q->dma_alignment : 511;
1111 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1114 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1115 return !(addr & alignment) && !(len & alignment);
1118 /* assumes size > 256 */
1119 static inline unsigned int blksize_bits(unsigned int size)
1121 unsigned int bits = 8;
1125 } while (size > 256);
1129 static inline unsigned int block_size(struct block_device *bdev)
1131 return bdev->bd_block_size;
1134 static inline bool queue_flush_queueable(struct request_queue *q)
1136 return !q->flush_not_queueable;
1139 typedef struct {struct page *v;} Sector;
1141 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1143 static inline void put_dev_sector(Sector p)
1145 page_cache_release(p.v);
1149 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1151 #ifdef CONFIG_BLK_CGROUP
1153 * This should not be using sched_clock(). A real patch is in progress
1154 * to fix this up, until that is in place we need to disable preemption
1155 * around sched_clock() in this function and set_io_start_time_ns().
1157 static inline void set_start_time_ns(struct request *req)
1160 req->start_time_ns = sched_clock();
1164 static inline void set_io_start_time_ns(struct request *req)
1167 req->io_start_time_ns = sched_clock();
1171 static inline uint64_t rq_start_time_ns(struct request *req)
1173 return req->start_time_ns;
1176 static inline uint64_t rq_io_start_time_ns(struct request *req)
1178 return req->io_start_time_ns;
1181 static inline void set_start_time_ns(struct request *req) {}
1182 static inline void set_io_start_time_ns(struct request *req) {}
1183 static inline uint64_t rq_start_time_ns(struct request *req)
1187 static inline uint64_t rq_io_start_time_ns(struct request *req)
1193 #ifdef CONFIG_BLK_DEV_THROTTLING
1194 extern int blk_throtl_init(struct request_queue *q);
1195 extern void blk_throtl_exit(struct request_queue *q);
1196 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1197 #else /* CONFIG_BLK_DEV_THROTTLING */
1198 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1203 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1204 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1205 #endif /* CONFIG_BLK_DEV_THROTTLING */
1207 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1208 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1209 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1210 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1212 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1214 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1215 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1217 struct blk_integrity_exchg {
1221 unsigned int data_size;
1222 unsigned short sector_size;
1223 const char *disk_name;
1226 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1227 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1228 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1229 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1231 struct blk_integrity {
1232 integrity_gen_fn *generate_fn;
1233 integrity_vrfy_fn *verify_fn;
1234 integrity_set_tag_fn *set_tag_fn;
1235 integrity_get_tag_fn *get_tag_fn;
1237 unsigned short flags;
1238 unsigned short tuple_size;
1239 unsigned short sector_size;
1240 unsigned short tag_size;
1244 struct kobject kobj;
1247 extern bool blk_integrity_is_initialized(struct gendisk *);
1248 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1249 extern void blk_integrity_unregister(struct gendisk *);
1250 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1251 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1252 struct scatterlist *);
1253 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1254 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1256 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1260 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1262 return bdev->bd_disk->integrity;
1265 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1267 return disk->integrity;
1270 static inline int blk_integrity_rq(struct request *rq)
1272 if (rq->bio == NULL)
1275 return bio_integrity(rq->bio);
1278 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1281 q->limits.max_integrity_segments = segs;
1284 static inline unsigned short
1285 queue_max_integrity_segments(struct request_queue *q)
1287 return q->limits.max_integrity_segments;
1290 #else /* CONFIG_BLK_DEV_INTEGRITY */
1292 #define blk_integrity_rq(rq) (0)
1293 #define blk_rq_count_integrity_sg(a, b) (0)
1294 #define blk_rq_map_integrity_sg(a, b, c) (0)
1295 #define bdev_get_integrity(a) (0)
1296 #define blk_get_integrity(a) (0)
1297 #define blk_integrity_compare(a, b) (0)
1298 #define blk_integrity_register(a, b) (0)
1299 #define blk_integrity_unregister(a) do { } while (0)
1300 #define blk_queue_max_integrity_segments(a, b) do { } while (0)
1301 #define queue_max_integrity_segments(a) (0)
1302 #define blk_integrity_merge_rq(a, b, c) (0)
1303 #define blk_integrity_merge_bio(a, b, c) (0)
1304 #define blk_integrity_is_initialized(a) (0)
1306 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1308 struct block_device_operations {
1309 int (*open) (struct block_device *, fmode_t);
1310 int (*release) (struct gendisk *, fmode_t);
1311 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1312 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1313 int (*direct_access) (struct block_device *, sector_t,
1314 void **, unsigned long *);
1315 unsigned int (*check_events) (struct gendisk *disk,
1316 unsigned int clearing);
1317 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1318 int (*media_changed) (struct gendisk *);
1319 void (*unlock_native_capacity) (struct gendisk *);
1320 int (*revalidate_disk) (struct gendisk *);
1321 int (*getgeo)(struct block_device *, struct hd_geometry *);
1322 /* this callback is with swap_lock and sometimes page table lock held */
1323 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1324 struct module *owner;
1327 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1329 #else /* CONFIG_BLOCK */
1331 * stubs for when the block layer is configured out
1333 #define buffer_heads_over_limit 0
1335 static inline long nr_blockdev_pages(void)
1343 static inline void blk_start_plug(struct blk_plug *plug)
1347 static inline void blk_finish_plug(struct blk_plug *plug)
1351 static inline void blk_flush_plug(struct task_struct *task)
1355 static inline void blk_schedule_flush_plug(struct task_struct *task)
1360 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1365 #endif /* CONFIG_BLOCK */