1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
4 #include <linux/sched.h>
8 #include <linux/major.h>
9 #include <linux/genhd.h>
10 #include <linux/list.h>
11 #include <linux/llist.h>
12 #include <linux/timer.h>
13 #include <linux/workqueue.h>
14 #include <linux/pagemap.h>
15 #include <linux/backing-dev.h>
16 #include <linux/wait.h>
17 #include <linux/mempool.h>
18 #include <linux/bio.h>
19 #include <linux/stringify.h>
20 #include <linux/gfp.h>
21 #include <linux/bsg.h>
22 #include <linux/smp.h>
23 #include <linux/rcupdate.h>
25 #include <asm/scatterlist.h>
28 struct scsi_ioctl_command;
31 struct elevator_queue;
32 struct request_pm_state;
39 #define BLKDEV_MIN_RQ 4
40 #define BLKDEV_MAX_RQ 128 /* Default maximum */
43 * Maximum number of blkcg policies allowed to be registered concurrently.
44 * Defined here to simplify include dependency.
46 #define BLKCG_MAX_POLS 2
49 typedef void (rq_end_io_fn)(struct request *, int);
51 #define BLK_RL_SYNCFULL (1U << 0)
52 #define BLK_RL_ASYNCFULL (1U << 1)
55 struct request_queue *q; /* the queue this rl belongs to */
56 #ifdef CONFIG_BLK_CGROUP
57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */
60 * count[], starved[], and wait[] are indexed by
61 * BLK_RW_SYNC/BLK_RW_ASYNC
66 wait_queue_head_t wait[2];
71 * request command types
73 enum rq_cmd_type_bits {
74 REQ_TYPE_FS = 1, /* fs request */
75 REQ_TYPE_BLOCK_PC, /* scsi command */
76 REQ_TYPE_SENSE, /* sense request */
77 REQ_TYPE_PM_SUSPEND, /* suspend request */
78 REQ_TYPE_PM_RESUME, /* resume request */
79 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
80 REQ_TYPE_SPECIAL, /* driver defined type */
82 * for ATA/ATAPI devices. this really doesn't belong here, ide should
83 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
84 * private REQ_LB opcodes to differentiate what type of request this is
86 REQ_TYPE_ATA_TASKFILE,
90 #define BLK_MAX_CDB 16
93 * try to put the fields that are referenced together in the same cacheline.
94 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
99 struct list_head queuelist;
100 struct llist_node ll_list;
103 struct call_single_data csd;
104 struct work_struct mq_flush_data;
107 struct request_queue *q;
108 struct blk_mq_ctx *mq_ctx;
111 enum rq_cmd_type_bits cmd_type;
112 unsigned long atomic_flags;
116 /* the following two fields are internal, NEVER access directly */
117 unsigned int __data_len; /* total data len */
118 sector_t __sector; /* sector cursor */
123 struct hlist_node hash; /* merge hash */
125 * The rb_node is only used inside the io scheduler, requests
126 * are pruned when moved to the dispatch queue. So let the
127 * completion_data share space with the rb_node.
130 struct rb_node rb_node; /* sort/lookup */
131 void *completion_data;
135 * Three pointers are available for the IO schedulers, if they need
136 * more they have to dynamically allocate it. Flush requests are
137 * never put on the IO scheduler. So let the flush fields share
138 * space with the elevator data.
148 struct list_head list;
149 rq_end_io_fn *saved_end_io;
153 struct gendisk *rq_disk;
154 struct hd_struct *part;
155 unsigned long start_time;
156 #ifdef CONFIG_BLK_CGROUP
157 struct request_list *rl; /* rl this rq is alloced from */
158 unsigned long long start_time_ns;
159 unsigned long long io_start_time_ns; /* when passed to hardware */
161 /* Number of scatter-gather DMA addr+len pairs after
162 * physical address coalescing is performed.
164 unsigned short nr_phys_segments;
165 #if defined(CONFIG_BLK_DEV_INTEGRITY)
166 unsigned short nr_integrity_segments;
169 unsigned short ioprio;
171 void *special; /* opaque pointer available for LLD use */
172 char *buffer; /* kaddr of the current segment if available */
178 * when request is used as a packet command carrier
180 unsigned char __cmd[BLK_MAX_CDB];
182 unsigned short cmd_len;
184 unsigned int extra_len; /* length of alignment and padding */
185 unsigned int sense_len;
186 unsigned int resid_len; /* residual count */
189 unsigned long deadline;
190 struct list_head timeout_list;
191 unsigned int timeout;
195 * completion callback.
197 rq_end_io_fn *end_io;
201 struct request *next_rq;
204 static inline unsigned short req_get_ioprio(struct request *req)
210 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
211 * requests. Some step values could eventually be made generic.
213 struct request_pm_state
215 /* PM state machine step value, currently driver specific */
217 /* requested PM state value (S1, S2, S3, S4, ...) */
219 void* data; /* for driver use */
222 #include <linux/elevator.h>
224 struct blk_queue_ctx;
226 typedef void (request_fn_proc) (struct request_queue *q);
227 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
228 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
229 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
232 struct bvec_merge_data {
233 struct block_device *bi_bdev;
238 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
240 typedef void (softirq_done_fn)(struct request *);
241 typedef int (dma_drain_needed_fn)(struct request *);
242 typedef int (lld_busy_fn) (struct request_queue *q);
243 typedef int (bsg_job_fn) (struct bsg_job *);
245 enum blk_eh_timer_return {
251 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
253 enum blk_queue_state {
258 struct blk_queue_tag {
259 struct request **tag_index; /* map of busy tags */
260 unsigned long *tag_map; /* bit map of free/busy tags */
261 int busy; /* current depth */
262 int max_depth; /* what we will send to device */
263 int real_max_depth; /* what the array can hold */
264 atomic_t refcnt; /* map can be shared */
267 #define BLK_SCSI_MAX_CMDS (256)
268 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
270 struct queue_limits {
271 unsigned long bounce_pfn;
272 unsigned long seg_boundary_mask;
274 unsigned int max_hw_sectors;
275 unsigned int max_sectors;
276 unsigned int max_segment_size;
277 unsigned int physical_block_size;
278 unsigned int alignment_offset;
281 unsigned int max_discard_sectors;
282 unsigned int max_write_same_sectors;
283 unsigned int discard_granularity;
284 unsigned int discard_alignment;
286 unsigned short logical_block_size;
287 unsigned short max_segments;
288 unsigned short max_integrity_segments;
290 unsigned char misaligned;
291 unsigned char discard_misaligned;
292 unsigned char cluster;
293 unsigned char discard_zeroes_data;
294 unsigned char raid_partial_stripes_expensive;
297 struct request_queue {
299 * Together with queue_head for cacheline sharing
301 struct list_head queue_head;
302 struct request *last_merge;
303 struct elevator_queue *elevator;
304 int nr_rqs[2]; /* # allocated [a]sync rqs */
305 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
308 * If blkcg is not used, @q->root_rl serves all requests. If blkcg
309 * is used, root blkg allocates from @q->root_rl and all other
310 * blkgs from their own blkg->rl. Which one to use should be
311 * determined using bio_request_list().
313 struct request_list root_rl;
315 request_fn_proc *request_fn;
316 make_request_fn *make_request_fn;
317 prep_rq_fn *prep_rq_fn;
318 unprep_rq_fn *unprep_rq_fn;
319 merge_bvec_fn *merge_bvec_fn;
320 softirq_done_fn *softirq_done_fn;
321 rq_timed_out_fn *rq_timed_out_fn;
322 dma_drain_needed_fn *dma_drain_needed;
323 lld_busy_fn *lld_busy_fn;
325 struct blk_mq_ops *mq_ops;
327 unsigned int *mq_map;
330 struct blk_mq_ctx *queue_ctx;
331 unsigned int nr_queues;
333 /* hw dispatch queues */
334 struct blk_mq_hw_ctx **queue_hw_ctx;
335 unsigned int nr_hw_queues;
338 * Dispatch queue sorting
341 struct request *boundary_rq;
344 * Delayed queue handling
346 struct delayed_work delay_work;
348 struct backing_dev_info backing_dev_info;
351 * The queue owner gets to use this for whatever they like.
352 * ll_rw_blk doesn't touch it.
357 * various queue flags, see QUEUE_* below
359 unsigned long queue_flags;
362 * ida allocated id for this queue. Used to index queues from
368 * queue needs bounce pages for pages above this limit
373 * protects queue structures from reentrancy. ->__queue_lock should
374 * _never_ be used directly, it is queue private. always use
377 spinlock_t __queue_lock;
378 spinlock_t *queue_lock;
388 struct kobject mq_kobj;
390 #ifdef CONFIG_PM_RUNTIME
393 unsigned int nr_pending;
399 unsigned long nr_requests; /* Max # of requests */
400 unsigned int nr_congestion_on;
401 unsigned int nr_congestion_off;
402 unsigned int nr_batching;
404 unsigned int dma_drain_size;
405 void *dma_drain_buffer;
406 unsigned int dma_pad_mask;
407 unsigned int dma_alignment;
409 struct blk_queue_tag *queue_tags;
410 struct list_head tag_busy_list;
412 unsigned int nr_sorted;
413 unsigned int in_flight[2];
415 * Number of active block driver functions for which blk_drain_queue()
416 * must wait. Must be incremented around functions that unlock the
417 * queue_lock internally, e.g. scsi_request_fn().
419 unsigned int request_fn_active;
421 unsigned int rq_timeout;
422 struct timer_list timeout;
423 struct list_head timeout_list;
425 struct list_head icq_list;
426 #ifdef CONFIG_BLK_CGROUP
427 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);
428 struct blkcg_gq *root_blkg;
429 struct list_head blkg_list;
432 struct queue_limits limits;
437 unsigned int sg_timeout;
438 unsigned int sg_reserved_size;
440 #ifdef CONFIG_BLK_DEV_IO_TRACE
441 struct blk_trace *blk_trace;
444 * for flush operations
446 unsigned int flush_flags;
447 unsigned int flush_not_queueable:1;
448 unsigned int flush_queue_delayed:1;
449 unsigned int flush_pending_idx:1;
450 unsigned int flush_running_idx:1;
451 unsigned long flush_pending_since;
452 struct list_head flush_queue[2];
453 struct list_head flush_data_in_flight;
455 struct request flush_rq;
457 spinlock_t mq_flush_lock;
458 struct work_struct mq_flush_work;
462 struct mutex sysfs_lock;
466 #if defined(CONFIG_BLK_DEV_BSG)
467 bsg_job_fn *bsg_job_fn;
469 struct bsg_class_device bsg_dev;
472 #ifdef CONFIG_BLK_DEV_THROTTLING
474 struct throtl_data *td;
476 struct rcu_head rcu_head;
477 wait_queue_head_t mq_freeze_wq;
478 struct percpu_counter mq_usage_counter;
479 struct list_head all_q_node;
482 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
483 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
484 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
485 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
486 #define QUEUE_FLAG_DYING 5 /* queue being torn down */
487 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */
488 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
489 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
490 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
491 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
492 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
493 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
494 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
495 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
496 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
497 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
498 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
499 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
500 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
501 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
502 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
504 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
505 (1 << QUEUE_FLAG_STACKABLE) | \
506 (1 << QUEUE_FLAG_SAME_COMP) | \
507 (1 << QUEUE_FLAG_ADD_RANDOM))
509 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
510 (1 << QUEUE_FLAG_SAME_COMP))
512 static inline void queue_lockdep_assert_held(struct request_queue *q)
515 lockdep_assert_held(q->queue_lock);
518 static inline void queue_flag_set_unlocked(unsigned int flag,
519 struct request_queue *q)
521 __set_bit(flag, &q->queue_flags);
524 static inline int queue_flag_test_and_clear(unsigned int flag,
525 struct request_queue *q)
527 queue_lockdep_assert_held(q);
529 if (test_bit(flag, &q->queue_flags)) {
530 __clear_bit(flag, &q->queue_flags);
537 static inline int queue_flag_test_and_set(unsigned int flag,
538 struct request_queue *q)
540 queue_lockdep_assert_held(q);
542 if (!test_bit(flag, &q->queue_flags)) {
543 __set_bit(flag, &q->queue_flags);
550 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
552 queue_lockdep_assert_held(q);
553 __set_bit(flag, &q->queue_flags);
556 static inline void queue_flag_clear_unlocked(unsigned int flag,
557 struct request_queue *q)
559 __clear_bit(flag, &q->queue_flags);
562 static inline int queue_in_flight(struct request_queue *q)
564 return q->in_flight[0] + q->in_flight[1];
567 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
569 queue_lockdep_assert_held(q);
570 __clear_bit(flag, &q->queue_flags);
573 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
574 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
575 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
576 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
577 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
578 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
579 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
580 #define blk_queue_noxmerges(q) \
581 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
582 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
583 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
584 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
585 #define blk_queue_stackable(q) \
586 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
587 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
588 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
589 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
591 #define blk_noretry_request(rq) \
592 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
593 REQ_FAILFAST_DRIVER))
595 #define blk_account_rq(rq) \
596 (((rq)->cmd_flags & REQ_STARTED) && \
597 ((rq)->cmd_type == REQ_TYPE_FS))
599 #define blk_pm_request(rq) \
600 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
601 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
603 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
604 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
605 /* rq->queuelist of dequeued request must be list_empty() */
606 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
608 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
610 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
612 static inline unsigned int blk_queue_cluster(struct request_queue *q)
614 return q->limits.cluster;
618 * We regard a request as sync, if either a read or a sync write
620 static inline bool rw_is_sync(unsigned int rw_flags)
622 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
625 static inline bool rq_is_sync(struct request *rq)
627 return rw_is_sync(rq->cmd_flags);
630 static inline bool blk_rl_full(struct request_list *rl, bool sync)
632 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
634 return rl->flags & flag;
637 static inline void blk_set_rl_full(struct request_list *rl, bool sync)
639 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
644 static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
646 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
651 static inline bool rq_mergeable(struct request *rq)
653 if (rq->cmd_type != REQ_TYPE_FS)
656 if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
662 static inline bool blk_check_merge_flags(unsigned int flags1,
665 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
668 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
671 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME))
677 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
679 if (bio_data(a) == bio_data(b))
686 * q->prep_rq_fn return values
688 #define BLKPREP_OK 0 /* serve it */
689 #define BLKPREP_KILL 1 /* fatal error, kill */
690 #define BLKPREP_DEFER 2 /* leave on queue */
692 extern unsigned long blk_max_low_pfn, blk_max_pfn;
695 * standard bounce addresses:
697 * BLK_BOUNCE_HIGH : bounce all highmem pages
698 * BLK_BOUNCE_ANY : don't bounce anything
699 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
702 #if BITS_PER_LONG == 32
703 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
705 #define BLK_BOUNCE_HIGH -1ULL
707 #define BLK_BOUNCE_ANY (-1ULL)
708 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
711 * default timeout for SG_IO if none specified
713 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
714 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
717 extern int init_emergency_isa_pool(void);
718 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
720 static inline int init_emergency_isa_pool(void)
724 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
727 #endif /* CONFIG_MMU */
733 unsigned long offset;
738 struct req_iterator {
739 struct bvec_iter iter;
743 /* This should not be used directly - use rq_for_each_segment */
744 #define for_each_bio(_bio) \
745 for (; _bio; _bio = _bio->bi_next)
746 #define __rq_for_each_bio(_bio, rq) \
748 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
750 #define rq_for_each_segment(bvl, _rq, _iter) \
751 __rq_for_each_bio(_iter.bio, _rq) \
752 bio_for_each_segment(bvl, _iter.bio, _iter.iter)
754 #define rq_iter_last(bvec, _iter) \
755 (_iter.bio->bi_next == NULL && \
756 bio_iter_last(bvec, _iter.iter))
758 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
759 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
761 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
762 extern void rq_flush_dcache_pages(struct request *rq);
764 static inline void rq_flush_dcache_pages(struct request *rq)
769 extern int blk_register_queue(struct gendisk *disk);
770 extern void blk_unregister_queue(struct gendisk *disk);
771 extern void generic_make_request(struct bio *bio);
772 extern void blk_rq_init(struct request_queue *q, struct request *rq);
773 extern void blk_put_request(struct request *);
774 extern void __blk_put_request(struct request_queue *, struct request *);
775 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
776 extern struct request *blk_make_request(struct request_queue *, struct bio *,
778 extern void blk_requeue_request(struct request_queue *, struct request *);
779 extern void blk_add_request_payload(struct request *rq, struct page *page,
781 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
782 extern int blk_lld_busy(struct request_queue *q);
783 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
784 struct bio_set *bs, gfp_t gfp_mask,
785 int (*bio_ctr)(struct bio *, struct bio *, void *),
787 extern void blk_rq_unprep_clone(struct request *rq);
788 extern int blk_insert_cloned_request(struct request_queue *q,
790 extern void blk_delay_queue(struct request_queue *, unsigned long);
791 extern void blk_recount_segments(struct request_queue *, struct bio *);
792 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
793 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
794 unsigned int, void __user *);
795 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
796 unsigned int, void __user *);
797 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
798 struct scsi_ioctl_command __user *);
800 extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
803 * A queue has just exitted congestion. Note this in the global counter of
804 * congested queues, and wake up anyone who was waiting for requests to be
807 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
809 clear_bdi_congested(&q->backing_dev_info, sync);
813 * A queue has just entered congestion. Flag that in the queue's VM-visible
814 * state flags and increment the global gounter of congested queues.
816 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
818 set_bdi_congested(&q->backing_dev_info, sync);
821 extern void blk_start_queue(struct request_queue *q);
822 extern void blk_stop_queue(struct request_queue *q);
823 extern void blk_sync_queue(struct request_queue *q);
824 extern void __blk_stop_queue(struct request_queue *q);
825 extern void __blk_run_queue(struct request_queue *q);
826 extern void blk_run_queue(struct request_queue *);
827 extern void blk_run_queue_async(struct request_queue *q);
828 extern int blk_rq_map_user(struct request_queue *, struct request *,
829 struct rq_map_data *, void __user *, unsigned long,
831 extern int blk_rq_unmap_user(struct bio *);
832 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
833 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
834 struct rq_map_data *, struct sg_iovec *, int,
835 unsigned int, gfp_t);
836 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
837 struct request *, int);
838 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
839 struct request *, int, rq_end_io_fn *);
841 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
843 return bdev->bd_disk->queue;
847 * blk_rq_pos() : the current sector
848 * blk_rq_bytes() : bytes left in the entire request
849 * blk_rq_cur_bytes() : bytes left in the current segment
850 * blk_rq_err_bytes() : bytes left till the next error boundary
851 * blk_rq_sectors() : sectors left in the entire request
852 * blk_rq_cur_sectors() : sectors left in the current segment
854 static inline sector_t blk_rq_pos(const struct request *rq)
859 static inline unsigned int blk_rq_bytes(const struct request *rq)
861 return rq->__data_len;
864 static inline int blk_rq_cur_bytes(const struct request *rq)
866 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
869 extern unsigned int blk_rq_err_bytes(const struct request *rq);
871 static inline unsigned int blk_rq_sectors(const struct request *rq)
873 return blk_rq_bytes(rq) >> 9;
876 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
878 return blk_rq_cur_bytes(rq) >> 9;
881 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
882 unsigned int cmd_flags)
884 if (unlikely(cmd_flags & REQ_DISCARD))
885 return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
887 if (unlikely(cmd_flags & REQ_WRITE_SAME))
888 return q->limits.max_write_same_sectors;
890 return q->limits.max_sectors;
893 static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
895 struct request_queue *q = rq->q;
897 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
898 return q->limits.max_hw_sectors;
900 return blk_queue_get_max_sectors(q, rq->cmd_flags);
903 static inline unsigned int blk_rq_count_bios(struct request *rq)
905 unsigned int nr_bios = 0;
908 __rq_for_each_bio(bio, rq)
915 * Request issue related functions.
917 extern struct request *blk_peek_request(struct request_queue *q);
918 extern void blk_start_request(struct request *rq);
919 extern struct request *blk_fetch_request(struct request_queue *q);
922 * Request completion related functions.
924 * blk_update_request() completes given number of bytes and updates
925 * the request without completing it.
927 * blk_end_request() and friends. __blk_end_request() must be called
928 * with the request queue spinlock acquired.
930 * Several drivers define their own end_request and call
931 * blk_end_request() for parts of the original function.
932 * This prevents code duplication in drivers.
934 extern bool blk_update_request(struct request *rq, int error,
935 unsigned int nr_bytes);
936 extern bool blk_end_request(struct request *rq, int error,
937 unsigned int nr_bytes);
938 extern void blk_end_request_all(struct request *rq, int error);
939 extern bool blk_end_request_cur(struct request *rq, int error);
940 extern bool blk_end_request_err(struct request *rq, int error);
941 extern bool __blk_end_request(struct request *rq, int error,
942 unsigned int nr_bytes);
943 extern void __blk_end_request_all(struct request *rq, int error);
944 extern bool __blk_end_request_cur(struct request *rq, int error);
945 extern bool __blk_end_request_err(struct request *rq, int error);
947 extern void blk_complete_request(struct request *);
948 extern void __blk_complete_request(struct request *);
949 extern void blk_abort_request(struct request *);
950 extern void blk_unprep_request(struct request *);
953 * Access functions for manipulating queue properties
955 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
956 spinlock_t *lock, int node_id);
957 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
958 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
959 request_fn_proc *, spinlock_t *);
960 extern void blk_cleanup_queue(struct request_queue *);
961 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
962 extern void blk_queue_bounce_limit(struct request_queue *, u64);
963 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
964 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
965 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
966 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
967 extern void blk_queue_max_discard_sectors(struct request_queue *q,
968 unsigned int max_discard_sectors);
969 extern void blk_queue_max_write_same_sectors(struct request_queue *q,
970 unsigned int max_write_same_sectors);
971 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
972 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
973 extern void blk_queue_alignment_offset(struct request_queue *q,
974 unsigned int alignment);
975 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
976 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
977 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
978 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
979 extern void blk_set_default_limits(struct queue_limits *lim);
980 extern void blk_set_stacking_limits(struct queue_limits *lim);
981 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
983 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
985 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
987 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
988 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
989 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
990 extern int blk_queue_dma_drain(struct request_queue *q,
991 dma_drain_needed_fn *dma_drain_needed,
992 void *buf, unsigned int size);
993 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
994 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
995 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
996 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
997 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
998 extern void blk_queue_dma_alignment(struct request_queue *, int);
999 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1000 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1001 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1002 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1003 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
1004 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1005 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1007 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1008 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
1009 struct scatterlist *sglist);
1010 extern void blk_dump_rq_flags(struct request *, char *);
1011 extern long nr_blockdev_pages(void);
1013 bool __must_check blk_get_queue(struct request_queue *);
1014 struct request_queue *blk_alloc_queue(gfp_t);
1015 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1016 extern void blk_put_queue(struct request_queue *);
1019 * block layer runtime pm functions
1021 #ifdef CONFIG_PM_RUNTIME
1022 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
1023 extern int blk_pre_runtime_suspend(struct request_queue *q);
1024 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
1025 extern void blk_pre_runtime_resume(struct request_queue *q);
1026 extern void blk_post_runtime_resume(struct request_queue *q, int err);
1028 static inline void blk_pm_runtime_init(struct request_queue *q,
1029 struct device *dev) {}
1030 static inline int blk_pre_runtime_suspend(struct request_queue *q)
1034 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
1035 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
1036 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
1040 * blk_plug permits building a queue of related requests by holding the I/O
1041 * fragments for a short period. This allows merging of sequential requests
1042 * into single larger request. As the requests are moved from a per-task list to
1043 * the device's request_queue in a batch, this results in improved scalability
1044 * as the lock contention for request_queue lock is reduced.
1046 * It is ok not to disable preemption when adding the request to the plug list
1047 * or when attempting a merge, because blk_schedule_flush_list() will only flush
1048 * the plug list when the task sleeps by itself. For details, please see
1049 * schedule() where blk_schedule_flush_plug() is called.
1052 unsigned long magic; /* detect uninitialized use-cases */
1053 struct list_head list; /* requests */
1054 struct list_head mq_list; /* blk-mq requests */
1055 struct list_head cb_list; /* md requires an unplug callback */
1057 #define BLK_MAX_REQUEST_COUNT 16
1060 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool);
1061 struct blk_plug_cb {
1062 struct list_head list;
1063 blk_plug_cb_fn callback;
1066 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug,
1067 void *data, int size);
1068 extern void blk_start_plug(struct blk_plug *);
1069 extern void blk_finish_plug(struct blk_plug *);
1070 extern void blk_flush_plug_list(struct blk_plug *, bool);
1072 static inline void blk_flush_plug(struct task_struct *tsk)
1074 struct blk_plug *plug = tsk->plug;
1077 blk_flush_plug_list(plug, false);
1080 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
1082 struct blk_plug *plug = tsk->plug;
1085 blk_flush_plug_list(plug, true);
1088 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1090 struct blk_plug *plug = tsk->plug;
1093 (!list_empty(&plug->list) ||
1094 !list_empty(&plug->mq_list) ||
1095 !list_empty(&plug->cb_list));
1101 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
1102 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1103 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1104 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1105 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
1106 extern void blk_queue_free_tags(struct request_queue *);
1107 extern int blk_queue_resize_tags(struct request_queue *, int);
1108 extern void blk_queue_invalidate_tags(struct request_queue *);
1109 extern struct blk_queue_tag *blk_init_tags(int);
1110 extern void blk_free_tags(struct blk_queue_tag *);
1112 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1115 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1117 return bqt->tag_index[tag];
1120 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
1122 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
1123 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
1124 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
1125 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
1126 sector_t nr_sects, gfp_t gfp_mask, struct page *page);
1127 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
1128 sector_t nr_sects, gfp_t gfp_mask);
1129 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
1130 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
1132 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
1133 nr_blocks << (sb->s_blocksize_bits - 9),
1136 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
1137 sector_t nr_blocks, gfp_t gfp_mask)
1139 return blkdev_issue_zeroout(sb->s_bdev,
1140 block << (sb->s_blocksize_bits - 9),
1141 nr_blocks << (sb->s_blocksize_bits - 9),
1145 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
1147 enum blk_default_limits {
1148 BLK_MAX_SEGMENTS = 128,
1149 BLK_SAFE_MAX_SECTORS = 255,
1150 BLK_DEF_MAX_SECTORS = 1024,
1151 BLK_MAX_SEGMENT_SIZE = 65536,
1152 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
1155 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1157 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
1159 return q->limits.bounce_pfn;
1162 static inline unsigned long queue_segment_boundary(struct request_queue *q)
1164 return q->limits.seg_boundary_mask;
1167 static inline unsigned int queue_max_sectors(struct request_queue *q)
1169 return q->limits.max_sectors;
1172 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1174 return q->limits.max_hw_sectors;
1177 static inline unsigned short queue_max_segments(struct request_queue *q)
1179 return q->limits.max_segments;
1182 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1184 return q->limits.max_segment_size;
1187 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1191 if (q && q->limits.logical_block_size)
1192 retval = q->limits.logical_block_size;
1197 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1199 return queue_logical_block_size(bdev_get_queue(bdev));
1202 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1204 return q->limits.physical_block_size;
1207 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1209 return queue_physical_block_size(bdev_get_queue(bdev));
1212 static inline unsigned int queue_io_min(struct request_queue *q)
1214 return q->limits.io_min;
1217 static inline int bdev_io_min(struct block_device *bdev)
1219 return queue_io_min(bdev_get_queue(bdev));
1222 static inline unsigned int queue_io_opt(struct request_queue *q)
1224 return q->limits.io_opt;
1227 static inline int bdev_io_opt(struct block_device *bdev)
1229 return queue_io_opt(bdev_get_queue(bdev));
1232 static inline int queue_alignment_offset(struct request_queue *q)
1234 if (q->limits.misaligned)
1237 return q->limits.alignment_offset;
1240 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1242 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1243 unsigned int alignment = (sector << 9) & (granularity - 1);
1245 return (granularity + lim->alignment_offset - alignment)
1246 & (granularity - 1);
1249 static inline int bdev_alignment_offset(struct block_device *bdev)
1251 struct request_queue *q = bdev_get_queue(bdev);
1253 if (q->limits.misaligned)
1256 if (bdev != bdev->bd_contains)
1257 return bdev->bd_part->alignment_offset;
1259 return q->limits.alignment_offset;
1262 static inline int queue_discard_alignment(struct request_queue *q)
1264 if (q->limits.discard_misaligned)
1267 return q->limits.discard_alignment;
1270 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1272 unsigned int alignment, granularity, offset;
1274 if (!lim->max_discard_sectors)
1277 /* Why are these in bytes, not sectors? */
1278 alignment = lim->discard_alignment >> 9;
1279 granularity = lim->discard_granularity >> 9;
1283 /* Offset of the partition start in 'granularity' sectors */
1284 offset = sector_div(sector, granularity);
1286 /* And why do we do this modulus *again* in blkdev_issue_discard()? */
1287 offset = (granularity + alignment - offset) % granularity;
1289 /* Turn it back into bytes, gaah */
1293 static inline int bdev_discard_alignment(struct block_device *bdev)
1295 struct request_queue *q = bdev_get_queue(bdev);
1297 if (bdev != bdev->bd_contains)
1298 return bdev->bd_part->discard_alignment;
1300 return q->limits.discard_alignment;
1303 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1305 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1311 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1313 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1316 static inline unsigned int bdev_write_same(struct block_device *bdev)
1318 struct request_queue *q = bdev_get_queue(bdev);
1321 return q->limits.max_write_same_sectors;
1326 static inline int queue_dma_alignment(struct request_queue *q)
1328 return q ? q->dma_alignment : 511;
1331 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1334 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1335 return !(addr & alignment) && !(len & alignment);
1338 /* assumes size > 256 */
1339 static inline unsigned int blksize_bits(unsigned int size)
1341 unsigned int bits = 8;
1345 } while (size > 256);
1349 static inline unsigned int block_size(struct block_device *bdev)
1351 return bdev->bd_block_size;
1354 static inline bool queue_flush_queueable(struct request_queue *q)
1356 return !q->flush_not_queueable;
1359 typedef struct {struct page *v;} Sector;
1361 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1363 static inline void put_dev_sector(Sector p)
1365 page_cache_release(p.v);
1369 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1370 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
1372 #ifdef CONFIG_BLK_CGROUP
1374 * This should not be using sched_clock(). A real patch is in progress
1375 * to fix this up, until that is in place we need to disable preemption
1376 * around sched_clock() in this function and set_io_start_time_ns().
1378 static inline void set_start_time_ns(struct request *req)
1381 req->start_time_ns = sched_clock();
1385 static inline void set_io_start_time_ns(struct request *req)
1388 req->io_start_time_ns = sched_clock();
1392 static inline uint64_t rq_start_time_ns(struct request *req)
1394 return req->start_time_ns;
1397 static inline uint64_t rq_io_start_time_ns(struct request *req)
1399 return req->io_start_time_ns;
1402 static inline void set_start_time_ns(struct request *req) {}
1403 static inline void set_io_start_time_ns(struct request *req) {}
1404 static inline uint64_t rq_start_time_ns(struct request *req)
1408 static inline uint64_t rq_io_start_time_ns(struct request *req)
1414 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1415 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1416 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1417 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1419 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1421 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1422 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1424 struct blk_integrity_exchg {
1428 unsigned int data_size;
1429 unsigned short sector_size;
1430 const char *disk_name;
1433 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1434 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1435 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1436 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1438 struct blk_integrity {
1439 integrity_gen_fn *generate_fn;
1440 integrity_vrfy_fn *verify_fn;
1441 integrity_set_tag_fn *set_tag_fn;
1442 integrity_get_tag_fn *get_tag_fn;
1444 unsigned short flags;
1445 unsigned short tuple_size;
1446 unsigned short sector_size;
1447 unsigned short tag_size;
1451 struct kobject kobj;
1454 extern bool blk_integrity_is_initialized(struct gendisk *);
1455 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1456 extern void blk_integrity_unregister(struct gendisk *);
1457 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1458 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1459 struct scatterlist *);
1460 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1461 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1463 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1467 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1469 return bdev->bd_disk->integrity;
1472 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1474 return disk->integrity;
1477 static inline int blk_integrity_rq(struct request *rq)
1479 if (rq->bio == NULL)
1482 return bio_integrity(rq->bio);
1485 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1488 q->limits.max_integrity_segments = segs;
1491 static inline unsigned short
1492 queue_max_integrity_segments(struct request_queue *q)
1494 return q->limits.max_integrity_segments;
1497 #else /* CONFIG_BLK_DEV_INTEGRITY */
1500 struct block_device;
1502 struct blk_integrity;
1504 static inline int blk_integrity_rq(struct request *rq)
1508 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1513 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1515 struct scatterlist *s)
1519 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1523 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1527 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1531 static inline int blk_integrity_register(struct gendisk *d,
1532 struct blk_integrity *b)
1536 static inline void blk_integrity_unregister(struct gendisk *d)
1539 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1543 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1547 static inline int blk_integrity_merge_rq(struct request_queue *rq,
1553 static inline int blk_integrity_merge_bio(struct request_queue *rq,
1559 static inline bool blk_integrity_is_initialized(struct gendisk *g)
1564 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1566 struct block_device_operations {
1567 int (*open) (struct block_device *, fmode_t);
1568 void (*release) (struct gendisk *, fmode_t);
1569 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1570 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1571 int (*direct_access) (struct block_device *, sector_t,
1572 void **, unsigned long *);
1573 unsigned int (*check_events) (struct gendisk *disk,
1574 unsigned int clearing);
1575 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1576 int (*media_changed) (struct gendisk *);
1577 void (*unlock_native_capacity) (struct gendisk *);
1578 int (*revalidate_disk) (struct gendisk *);
1579 int (*getgeo)(struct block_device *, struct hd_geometry *);
1580 /* this callback is with swap_lock and sometimes page table lock held */
1581 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1582 struct module *owner;
1585 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1587 #else /* CONFIG_BLOCK */
1589 * stubs for when the block layer is configured out
1591 #define buffer_heads_over_limit 0
1593 static inline long nr_blockdev_pages(void)
1601 static inline void blk_start_plug(struct blk_plug *plug)
1605 static inline void blk_finish_plug(struct blk_plug *plug)
1609 static inline void blk_flush_plug(struct task_struct *task)
1613 static inline void blk_schedule_flush_plug(struct task_struct *task)
1618 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1623 #endif /* CONFIG_BLOCK */