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 flush_flags;
361 unsigned int flush_seq;
363 struct request flush_rq;
364 struct request *orig_flush_rq;
365 struct list_head pending_flushes;
367 struct mutex sysfs_lock;
369 #if defined(CONFIG_BLK_DEV_BSG)
370 struct bsg_class_device bsg_dev;
374 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
375 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
376 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
377 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
378 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
379 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
380 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
381 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
382 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
383 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
384 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
385 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
386 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
387 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
388 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
389 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
390 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
391 #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */
392 #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */
393 #define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */
394 #define QUEUE_FLAG_SECDISCARD 19 /* supports SECDISCARD */
396 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
397 (1 << QUEUE_FLAG_CLUSTER) | \
398 (1 << QUEUE_FLAG_STACKABLE) | \
399 (1 << QUEUE_FLAG_SAME_COMP) | \
400 (1 << QUEUE_FLAG_ADD_RANDOM))
402 static inline int queue_is_locked(struct request_queue *q)
405 spinlock_t *lock = q->queue_lock;
406 return lock && spin_is_locked(lock);
412 static inline void queue_flag_set_unlocked(unsigned int flag,
413 struct request_queue *q)
415 __set_bit(flag, &q->queue_flags);
418 static inline int queue_flag_test_and_clear(unsigned int flag,
419 struct request_queue *q)
421 WARN_ON_ONCE(!queue_is_locked(q));
423 if (test_bit(flag, &q->queue_flags)) {
424 __clear_bit(flag, &q->queue_flags);
431 static inline int queue_flag_test_and_set(unsigned int flag,
432 struct request_queue *q)
434 WARN_ON_ONCE(!queue_is_locked(q));
436 if (!test_bit(flag, &q->queue_flags)) {
437 __set_bit(flag, &q->queue_flags);
444 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
446 WARN_ON_ONCE(!queue_is_locked(q));
447 __set_bit(flag, &q->queue_flags);
450 static inline void queue_flag_clear_unlocked(unsigned int flag,
451 struct request_queue *q)
453 __clear_bit(flag, &q->queue_flags);
456 static inline int queue_in_flight(struct request_queue *q)
458 return q->in_flight[0] + q->in_flight[1];
461 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
463 WARN_ON_ONCE(!queue_is_locked(q));
464 __clear_bit(flag, &q->queue_flags);
467 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
468 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
469 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
470 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
471 #define blk_queue_noxmerges(q) \
472 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
473 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
474 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
475 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
476 #define blk_queue_stackable(q) \
477 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
478 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
479 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
480 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
482 #define blk_noretry_request(rq) \
483 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
484 REQ_FAILFAST_DRIVER))
486 #define blk_account_rq(rq) \
487 (((rq)->cmd_flags & REQ_STARTED) && \
488 ((rq)->cmd_type == REQ_TYPE_FS || \
489 ((rq)->cmd_flags & REQ_DISCARD)))
491 #define blk_pm_request(rq) \
492 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
493 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
495 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
496 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
497 /* rq->queuelist of dequeued request must be list_empty() */
498 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
500 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
502 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
505 * We regard a request as sync, if either a read or a sync write
507 static inline bool rw_is_sync(unsigned int rw_flags)
509 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
512 static inline bool rq_is_sync(struct request *rq)
514 return rw_is_sync(rq->cmd_flags);
517 static inline int blk_queue_full(struct request_queue *q, int sync)
520 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
521 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
524 static inline void blk_set_queue_full(struct request_queue *q, int sync)
527 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
529 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
532 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
535 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
537 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
542 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
543 * it already be started by driver.
545 #define RQ_NOMERGE_FLAGS \
546 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER | \
548 #define rq_mergeable(rq) \
549 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
550 (((rq)->cmd_flags & REQ_DISCARD) || \
551 (rq)->cmd_type == REQ_TYPE_FS))
554 * q->prep_rq_fn return values
556 #define BLKPREP_OK 0 /* serve it */
557 #define BLKPREP_KILL 1 /* fatal error, kill */
558 #define BLKPREP_DEFER 2 /* leave on queue */
560 extern unsigned long blk_max_low_pfn, blk_max_pfn;
563 * standard bounce addresses:
565 * BLK_BOUNCE_HIGH : bounce all highmem pages
566 * BLK_BOUNCE_ANY : don't bounce anything
567 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
570 #if BITS_PER_LONG == 32
571 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
573 #define BLK_BOUNCE_HIGH -1ULL
575 #define BLK_BOUNCE_ANY (-1ULL)
576 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
579 * default timeout for SG_IO if none specified
581 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
582 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
585 extern int init_emergency_isa_pool(void);
586 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
588 static inline int init_emergency_isa_pool(void)
592 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
595 #endif /* CONFIG_MMU */
601 unsigned long offset;
606 struct req_iterator {
611 /* This should not be used directly - use rq_for_each_segment */
612 #define for_each_bio(_bio) \
613 for (; _bio; _bio = _bio->bi_next)
614 #define __rq_for_each_bio(_bio, rq) \
616 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
618 #define rq_for_each_segment(bvl, _rq, _iter) \
619 __rq_for_each_bio(_iter.bio, _rq) \
620 bio_for_each_segment(bvl, _iter.bio, _iter.i)
622 #define rq_iter_last(rq, _iter) \
623 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
625 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
626 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
628 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
629 extern void rq_flush_dcache_pages(struct request *rq);
631 static inline void rq_flush_dcache_pages(struct request *rq)
636 extern int blk_register_queue(struct gendisk *disk);
637 extern void blk_unregister_queue(struct gendisk *disk);
638 extern void register_disk(struct gendisk *dev);
639 extern void generic_make_request(struct bio *bio);
640 extern void blk_rq_init(struct request_queue *q, struct request *rq);
641 extern void blk_put_request(struct request *);
642 extern void __blk_put_request(struct request_queue *, struct request *);
643 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
644 extern struct request *blk_make_request(struct request_queue *, struct bio *,
646 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
647 extern void blk_requeue_request(struct request_queue *, struct request *);
648 extern void blk_add_request_payload(struct request *rq, struct page *page,
650 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
651 extern int blk_lld_busy(struct request_queue *q);
652 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
653 struct bio_set *bs, gfp_t gfp_mask,
654 int (*bio_ctr)(struct bio *, struct bio *, void *),
656 extern void blk_rq_unprep_clone(struct request *rq);
657 extern int blk_insert_cloned_request(struct request_queue *q,
659 extern void blk_plug_device(struct request_queue *);
660 extern void blk_plug_device_unlocked(struct request_queue *);
661 extern int blk_remove_plug(struct request_queue *);
662 extern void blk_recount_segments(struct request_queue *, struct bio *);
663 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
664 unsigned int, void __user *);
665 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
666 struct scsi_ioctl_command __user *);
669 * A queue has just exitted congestion. Note this in the global counter of
670 * congested queues, and wake up anyone who was waiting for requests to be
673 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
675 clear_bdi_congested(&q->backing_dev_info, sync);
679 * A queue has just entered congestion. Flag that in the queue's VM-visible
680 * state flags and increment the global gounter of congested queues.
682 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
684 set_bdi_congested(&q->backing_dev_info, sync);
687 extern void blk_start_queue(struct request_queue *q);
688 extern void blk_stop_queue(struct request_queue *q);
689 extern void blk_sync_queue(struct request_queue *q);
690 extern void __blk_stop_queue(struct request_queue *q);
691 extern void __blk_run_queue(struct request_queue *);
692 extern void blk_run_queue(struct request_queue *);
693 extern int blk_rq_map_user(struct request_queue *, struct request *,
694 struct rq_map_data *, void __user *, unsigned long,
696 extern int blk_rq_unmap_user(struct bio *);
697 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
698 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
699 struct rq_map_data *, struct sg_iovec *, int,
700 unsigned int, gfp_t);
701 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
702 struct request *, int);
703 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
704 struct request *, int, rq_end_io_fn *);
705 extern void blk_unplug(struct request_queue *q);
707 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
709 return bdev->bd_disk->queue;
713 * blk_rq_pos() : the current sector
714 * blk_rq_bytes() : bytes left in the entire request
715 * blk_rq_cur_bytes() : bytes left in the current segment
716 * blk_rq_err_bytes() : bytes left till the next error boundary
717 * blk_rq_sectors() : sectors left in the entire request
718 * blk_rq_cur_sectors() : sectors left in the current segment
720 static inline sector_t blk_rq_pos(const struct request *rq)
725 static inline unsigned int blk_rq_bytes(const struct request *rq)
727 return rq->__data_len;
730 static inline int blk_rq_cur_bytes(const struct request *rq)
732 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
735 extern unsigned int blk_rq_err_bytes(const struct request *rq);
737 static inline unsigned int blk_rq_sectors(const struct request *rq)
739 return blk_rq_bytes(rq) >> 9;
742 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
744 return blk_rq_cur_bytes(rq) >> 9;
748 * Request issue related functions.
750 extern struct request *blk_peek_request(struct request_queue *q);
751 extern void blk_start_request(struct request *rq);
752 extern struct request *blk_fetch_request(struct request_queue *q);
755 * Request completion related functions.
757 * blk_update_request() completes given number of bytes and updates
758 * the request without completing it.
760 * blk_end_request() and friends. __blk_end_request() must be called
761 * with the request queue spinlock acquired.
763 * Several drivers define their own end_request and call
764 * blk_end_request() for parts of the original function.
765 * This prevents code duplication in drivers.
767 extern bool blk_update_request(struct request *rq, int error,
768 unsigned int nr_bytes);
769 extern bool blk_end_request(struct request *rq, int error,
770 unsigned int nr_bytes);
771 extern void blk_end_request_all(struct request *rq, int error);
772 extern bool blk_end_request_cur(struct request *rq, int error);
773 extern bool blk_end_request_err(struct request *rq, int error);
774 extern bool __blk_end_request(struct request *rq, int error,
775 unsigned int nr_bytes);
776 extern void __blk_end_request_all(struct request *rq, int error);
777 extern bool __blk_end_request_cur(struct request *rq, int error);
778 extern bool __blk_end_request_err(struct request *rq, int error);
780 extern void blk_complete_request(struct request *);
781 extern void __blk_complete_request(struct request *);
782 extern void blk_abort_request(struct request *);
783 extern void blk_abort_queue(struct request_queue *);
784 extern void blk_unprep_request(struct request *);
787 * Access functions for manipulating queue properties
789 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
790 spinlock_t *lock, int node_id);
791 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
793 spinlock_t *, int node_id);
794 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
795 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
796 request_fn_proc *, spinlock_t *);
797 extern void blk_cleanup_queue(struct request_queue *);
798 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
799 extern void blk_queue_bounce_limit(struct request_queue *, u64);
800 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
801 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
802 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
803 extern void blk_queue_max_discard_sectors(struct request_queue *q,
804 unsigned int max_discard_sectors);
805 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
806 extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
807 extern void blk_queue_alignment_offset(struct request_queue *q,
808 unsigned int alignment);
809 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
810 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
811 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
812 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
813 extern void blk_set_default_limits(struct queue_limits *lim);
814 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
816 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
818 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
820 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
821 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
822 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
823 extern int blk_queue_dma_drain(struct request_queue *q,
824 dma_drain_needed_fn *dma_drain_needed,
825 void *buf, unsigned int size);
826 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
827 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
828 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
829 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
830 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
831 extern void blk_queue_dma_alignment(struct request_queue *, int);
832 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
833 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
834 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
835 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
836 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
837 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
839 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
840 extern void blk_dump_rq_flags(struct request *, char *);
841 extern void generic_unplug_device(struct request_queue *);
842 extern long nr_blockdev_pages(void);
844 int blk_get_queue(struct request_queue *);
845 struct request_queue *blk_alloc_queue(gfp_t);
846 struct request_queue *blk_alloc_queue_node(gfp_t, int);
847 extern void blk_put_queue(struct request_queue *);
852 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
853 extern int blk_queue_start_tag(struct request_queue *, struct request *);
854 extern struct request *blk_queue_find_tag(struct request_queue *, int);
855 extern void blk_queue_end_tag(struct request_queue *, struct request *);
856 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
857 extern void blk_queue_free_tags(struct request_queue *);
858 extern int blk_queue_resize_tags(struct request_queue *, int);
859 extern void blk_queue_invalidate_tags(struct request_queue *);
860 extern struct blk_queue_tag *blk_init_tags(int);
861 extern void blk_free_tags(struct blk_queue_tag *);
863 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
866 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
868 return bqt->tag_index[tag];
871 BLKDEV_WAIT, /* wait for completion */
872 BLKDEV_SECURE, /* secure discard */
874 #define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
875 #define BLKDEV_IFL_SECURE (1 << BLKDEV_SECURE)
876 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
878 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
879 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
880 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
881 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
882 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
883 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
885 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
886 nr_blocks << (sb->s_blocksize_bits - 9),
890 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
892 enum blk_default_limits {
893 BLK_MAX_SEGMENTS = 128,
894 BLK_SAFE_MAX_SECTORS = 255,
895 BLK_DEF_MAX_SECTORS = 1024,
896 BLK_MAX_SEGMENT_SIZE = 65536,
897 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
900 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
902 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
904 return q->limits.bounce_pfn;
907 static inline unsigned long queue_segment_boundary(struct request_queue *q)
909 return q->limits.seg_boundary_mask;
912 static inline unsigned int queue_max_sectors(struct request_queue *q)
914 return q->limits.max_sectors;
917 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
919 return q->limits.max_hw_sectors;
922 static inline unsigned short queue_max_segments(struct request_queue *q)
924 return q->limits.max_segments;
927 static inline unsigned int queue_max_segment_size(struct request_queue *q)
929 return q->limits.max_segment_size;
932 static inline unsigned short queue_logical_block_size(struct request_queue *q)
936 if (q && q->limits.logical_block_size)
937 retval = q->limits.logical_block_size;
942 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
944 return queue_logical_block_size(bdev_get_queue(bdev));
947 static inline unsigned int queue_physical_block_size(struct request_queue *q)
949 return q->limits.physical_block_size;
952 static inline int bdev_physical_block_size(struct block_device *bdev)
954 return queue_physical_block_size(bdev_get_queue(bdev));
957 static inline unsigned int queue_io_min(struct request_queue *q)
959 return q->limits.io_min;
962 static inline int bdev_io_min(struct block_device *bdev)
964 return queue_io_min(bdev_get_queue(bdev));
967 static inline unsigned int queue_io_opt(struct request_queue *q)
969 return q->limits.io_opt;
972 static inline int bdev_io_opt(struct block_device *bdev)
974 return queue_io_opt(bdev_get_queue(bdev));
977 static inline int queue_alignment_offset(struct request_queue *q)
979 if (q->limits.misaligned)
982 return q->limits.alignment_offset;
985 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
987 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
988 unsigned int alignment = (sector << 9) & (granularity - 1);
990 return (granularity + lim->alignment_offset - alignment)
994 static inline int bdev_alignment_offset(struct block_device *bdev)
996 struct request_queue *q = bdev_get_queue(bdev);
998 if (q->limits.misaligned)
1001 if (bdev != bdev->bd_contains)
1002 return bdev->bd_part->alignment_offset;
1004 return q->limits.alignment_offset;
1007 static inline int queue_discard_alignment(struct request_queue *q)
1009 if (q->limits.discard_misaligned)
1012 return q->limits.discard_alignment;
1015 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1017 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1019 return (lim->discard_granularity + lim->discard_alignment - alignment)
1020 & (lim->discard_granularity - 1);
1023 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1025 if (q->limits.discard_zeroes_data == 1)
1031 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1033 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1036 static inline int queue_dma_alignment(struct request_queue *q)
1038 return q ? q->dma_alignment : 511;
1041 static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1044 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1045 return !((unsigned long)addr & alignment) && !(len & alignment);
1048 /* assumes size > 256 */
1049 static inline unsigned int blksize_bits(unsigned int size)
1051 unsigned int bits = 8;
1055 } while (size > 256);
1059 static inline unsigned int block_size(struct block_device *bdev)
1061 return bdev->bd_block_size;
1064 typedef struct {struct page *v;} Sector;
1066 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1068 static inline void put_dev_sector(Sector p)
1070 page_cache_release(p.v);
1074 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1076 #ifdef CONFIG_BLK_CGROUP
1078 * This should not be using sched_clock(). A real patch is in progress
1079 * to fix this up, until that is in place we need to disable preemption
1080 * around sched_clock() in this function and set_io_start_time_ns().
1082 static inline void set_start_time_ns(struct request *req)
1085 req->start_time_ns = sched_clock();
1089 static inline void set_io_start_time_ns(struct request *req)
1092 req->io_start_time_ns = sched_clock();
1096 static inline uint64_t rq_start_time_ns(struct request *req)
1098 return req->start_time_ns;
1101 static inline uint64_t rq_io_start_time_ns(struct request *req)
1103 return req->io_start_time_ns;
1106 static inline void set_start_time_ns(struct request *req) {}
1107 static inline void set_io_start_time_ns(struct request *req) {}
1108 static inline uint64_t rq_start_time_ns(struct request *req)
1112 static inline uint64_t rq_io_start_time_ns(struct request *req)
1118 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1119 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1120 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1121 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1123 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1125 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1126 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1128 struct blk_integrity_exchg {
1132 unsigned int data_size;
1133 unsigned short sector_size;
1134 const char *disk_name;
1137 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1138 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1139 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1140 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1142 struct blk_integrity {
1143 integrity_gen_fn *generate_fn;
1144 integrity_vrfy_fn *verify_fn;
1145 integrity_set_tag_fn *set_tag_fn;
1146 integrity_get_tag_fn *get_tag_fn;
1148 unsigned short flags;
1149 unsigned short tuple_size;
1150 unsigned short sector_size;
1151 unsigned short tag_size;
1155 struct kobject kobj;
1158 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1159 extern void blk_integrity_unregister(struct gendisk *);
1160 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1161 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1162 extern int blk_rq_count_integrity_sg(struct request *);
1165 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1167 return bdev->bd_disk->integrity;
1170 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1172 return disk->integrity;
1175 static inline int blk_integrity_rq(struct request *rq)
1177 if (rq->bio == NULL)
1180 return bio_integrity(rq->bio);
1183 #else /* CONFIG_BLK_DEV_INTEGRITY */
1185 #define blk_integrity_rq(rq) (0)
1186 #define blk_rq_count_integrity_sg(a) (0)
1187 #define blk_rq_map_integrity_sg(a, b) (0)
1188 #define bdev_get_integrity(a) (0)
1189 #define blk_get_integrity(a) (0)
1190 #define blk_integrity_compare(a, b) (0)
1191 #define blk_integrity_register(a, b) (0)
1192 #define blk_integrity_unregister(a) do { } while (0);
1194 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1196 struct block_device_operations {
1197 int (*open) (struct block_device *, fmode_t);
1198 int (*release) (struct gendisk *, fmode_t);
1199 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1200 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1201 int (*direct_access) (struct block_device *, sector_t,
1202 void **, unsigned long *);
1203 int (*media_changed) (struct gendisk *);
1204 void (*unlock_native_capacity) (struct gendisk *);
1205 int (*revalidate_disk) (struct gendisk *);
1206 int (*getgeo)(struct block_device *, struct hd_geometry *);
1207 /* this callback is with swap_lock and sometimes page table lock held */
1208 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1209 struct module *owner;
1212 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1214 #else /* CONFIG_BLOCK */
1216 * stubs for when the block layer is configured out
1218 #define buffer_heads_over_limit 0
1220 static inline long nr_blockdev_pages(void)
1225 #endif /* CONFIG_BLOCK */