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/bsg.h>
21 #include <asm/scatterlist.h>
23 struct scsi_ioctl_command
;
26 struct elevator_queue
;
27 typedef struct elevator_queue elevator_t
;
28 struct request_pm_state
;
33 #define BLKDEV_MIN_RQ 4
34 #define BLKDEV_MAX_RQ 128 /* Default maximum */
37 typedef void (rq_end_io_fn
)(struct request
*, int);
44 wait_queue_head_t wait
[2];
48 * request command types
50 enum rq_cmd_type_bits
{
51 REQ_TYPE_FS
= 1, /* fs request */
52 REQ_TYPE_BLOCK_PC
, /* scsi command */
53 REQ_TYPE_SENSE
, /* sense request */
54 REQ_TYPE_PM_SUSPEND
, /* suspend request */
55 REQ_TYPE_PM_RESUME
, /* resume request */
56 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
57 REQ_TYPE_SPECIAL
, /* driver defined type */
58 REQ_TYPE_LINUX_BLOCK
, /* generic block layer message */
60 * for ATA/ATAPI devices. this really doesn't belong here, ide should
61 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
62 * private REQ_LB opcodes to differentiate what type of request this is
64 REQ_TYPE_ATA_TASKFILE
,
69 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
70 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
73 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
74 * typically to differentiate REQ_TYPE_SPECIAL requests.
78 REQ_LB_OP_EJECT
= 0x40, /* eject request */
79 REQ_LB_OP_FLUSH
= 0x41, /* flush request */
80 REQ_LB_OP_DISCARD
= 0x42, /* discard sectors */
84 * request type modified bits. first two bits match BIO_RW* bits, important
87 __REQ_RW
, /* not set, read. set, write */
88 __REQ_FAILFAST
, /* no low level driver retries */
89 __REQ_DISCARD
, /* request to discard sectors */
90 __REQ_SORTED
, /* elevator knows about this request */
91 __REQ_SOFTBARRIER
, /* may not be passed by ioscheduler */
92 __REQ_HARDBARRIER
, /* may not be passed by drive either */
93 __REQ_FUA
, /* forced unit access */
94 __REQ_NOMERGE
, /* don't touch this for merging */
95 __REQ_STARTED
, /* drive already may have started this one */
96 __REQ_DONTPREP
, /* don't call prep for this one */
97 __REQ_QUEUED
, /* uses queueing */
98 __REQ_ELVPRIV
, /* elevator private data attached */
99 __REQ_FAILED
, /* set if the request failed */
100 __REQ_QUIET
, /* don't worry about errors */
101 __REQ_PREEMPT
, /* set for "ide_preempt" requests */
102 __REQ_ORDERED_COLOR
, /* is before or after barrier */
103 __REQ_RW_SYNC
, /* request is sync (O_DIRECT) */
104 __REQ_ALLOCED
, /* request came from our alloc pool */
105 __REQ_RW_META
, /* metadata io request */
106 __REQ_COPY_USER
, /* contains copies of user pages */
107 __REQ_INTEGRITY
, /* integrity metadata has been remapped */
108 __REQ_NR_BITS
, /* stops here */
111 #define REQ_RW (1 << __REQ_RW)
112 #define REQ_DISCARD (1 << __REQ_DISCARD)
113 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
114 #define REQ_SORTED (1 << __REQ_SORTED)
115 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
116 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
117 #define REQ_FUA (1 << __REQ_FUA)
118 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
119 #define REQ_STARTED (1 << __REQ_STARTED)
120 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
121 #define REQ_QUEUED (1 << __REQ_QUEUED)
122 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
123 #define REQ_FAILED (1 << __REQ_FAILED)
124 #define REQ_QUIET (1 << __REQ_QUIET)
125 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
126 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
127 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
128 #define REQ_ALLOCED (1 << __REQ_ALLOCED)
129 #define REQ_RW_META (1 << __REQ_RW_META)
130 #define REQ_COPY_USER (1 << __REQ_COPY_USER)
131 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
133 #define BLK_MAX_CDB 16
136 * try to put the fields that are referenced together in the same cacheline.
137 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
141 struct list_head queuelist
;
142 struct list_head donelist
;
144 struct request_queue
*q
;
146 unsigned int cmd_flags
;
147 enum rq_cmd_type_bits cmd_type
;
149 /* Maintain bio traversal state for part by part I/O submission.
150 * hard_* are block layer internals, no driver should touch them!
153 sector_t sector
; /* next sector to submit */
154 sector_t hard_sector
; /* next sector to complete */
155 unsigned long nr_sectors
; /* no. of sectors left to submit */
156 unsigned long hard_nr_sectors
; /* no. of sectors left to complete */
157 /* no. of sectors left to submit in the current segment */
158 unsigned int current_nr_sectors
;
160 /* no. of sectors left to complete in the current segment */
161 unsigned int hard_cur_sectors
;
166 struct hlist_node hash
; /* merge hash */
168 * The rb_node is only used inside the io scheduler, requests
169 * are pruned when moved to the dispatch queue. So let the
170 * completion_data share space with the rb_node.
173 struct rb_node rb_node
; /* sort/lookup */
174 void *completion_data
;
178 * two pointers are available for the IO schedulers, if they need
179 * more they have to dynamically allocate it.
181 void *elevator_private
;
182 void *elevator_private2
;
184 struct gendisk
*rq_disk
;
185 unsigned long start_time
;
187 /* Number of scatter-gather DMA addr+len pairs after
188 * physical address coalescing is performed.
190 unsigned short nr_phys_segments
;
192 unsigned short ioprio
;
203 * when request is used as a packet command carrier
205 unsigned short cmd_len
;
206 unsigned char __cmd
[BLK_MAX_CDB
];
209 unsigned int data_len
;
210 unsigned int extra_len
; /* length of alignment and padding */
211 unsigned int sense_len
;
215 unsigned int timeout
;
219 * completion callback.
221 rq_end_io_fn
*end_io
;
225 struct request
*next_rq
;
228 static inline unsigned short req_get_ioprio(struct request
*req
)
234 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
235 * requests. Some step values could eventually be made generic.
237 struct request_pm_state
239 /* PM state machine step value, currently driver specific */
241 /* requested PM state value (S1, S2, S3, S4, ...) */
243 void* data
; /* for driver use */
246 #include <linux/elevator.h>
248 typedef void (request_fn_proc
) (struct request_queue
*q
);
249 typedef int (make_request_fn
) (struct request_queue
*q
, struct bio
*bio
);
250 typedef int (prep_rq_fn
) (struct request_queue
*, struct request
*);
251 typedef void (unplug_fn
) (struct request_queue
*);
252 typedef int (prepare_discard_fn
) (struct request_queue
*, struct request
*);
255 struct bvec_merge_data
{
256 struct block_device
*bi_bdev
;
261 typedef int (merge_bvec_fn
) (struct request_queue
*, struct bvec_merge_data
*,
263 typedef void (prepare_flush_fn
) (struct request_queue
*, struct request
*);
264 typedef void (softirq_done_fn
)(struct request
*);
265 typedef int (dma_drain_needed_fn
)(struct request
*);
267 enum blk_queue_state
{
272 struct blk_queue_tag
{
273 struct request
**tag_index
; /* map of busy tags */
274 unsigned long *tag_map
; /* bit map of free/busy tags */
275 int busy
; /* current depth */
276 int max_depth
; /* what we will send to device */
277 int real_max_depth
; /* what the array can hold */
278 atomic_t refcnt
; /* map can be shared */
281 #define BLK_SCSI_MAX_CMDS (256)
282 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
284 struct blk_cmd_filter
{
285 unsigned long read_ok
[BLK_SCSI_CMD_PER_LONG
];
286 unsigned long write_ok
[BLK_SCSI_CMD_PER_LONG
];
293 * Together with queue_head for cacheline sharing
295 struct list_head queue_head
;
296 struct request
*last_merge
;
297 elevator_t
*elevator
;
300 * the queue request freelist, one for reads and one for writes
302 struct request_list rq
;
304 request_fn_proc
*request_fn
;
305 make_request_fn
*make_request_fn
;
306 prep_rq_fn
*prep_rq_fn
;
307 unplug_fn
*unplug_fn
;
308 prepare_discard_fn
*prepare_discard_fn
;
309 merge_bvec_fn
*merge_bvec_fn
;
310 prepare_flush_fn
*prepare_flush_fn
;
311 softirq_done_fn
*softirq_done_fn
;
312 dma_drain_needed_fn
*dma_drain_needed
;
315 * Dispatch queue sorting
318 struct request
*boundary_rq
;
321 * Auto-unplugging state
323 struct timer_list unplug_timer
;
324 int unplug_thresh
; /* After this many requests */
325 unsigned long unplug_delay
; /* After this many jiffies */
326 struct work_struct unplug_work
;
328 struct backing_dev_info backing_dev_info
;
331 * The queue owner gets to use this for whatever they like.
332 * ll_rw_blk doesn't touch it.
337 * queue needs bounce pages for pages above this limit
339 unsigned long bounce_pfn
;
343 * various queue flags, see QUEUE_* below
345 unsigned long queue_flags
;
348 * protects queue structures from reentrancy. ->__queue_lock should
349 * _never_ be used directly, it is queue private. always use
352 spinlock_t __queue_lock
;
353 spinlock_t
*queue_lock
;
363 unsigned long nr_requests
; /* Max # of requests */
364 unsigned int nr_congestion_on
;
365 unsigned int nr_congestion_off
;
366 unsigned int nr_batching
;
368 unsigned int max_sectors
;
369 unsigned int max_hw_sectors
;
370 unsigned short max_phys_segments
;
371 unsigned short max_hw_segments
;
372 unsigned short hardsect_size
;
373 unsigned int max_segment_size
;
375 unsigned long seg_boundary_mask
;
376 void *dma_drain_buffer
;
377 unsigned int dma_drain_size
;
378 unsigned int dma_pad_mask
;
379 unsigned int dma_alignment
;
381 struct blk_queue_tag
*queue_tags
;
382 struct list_head tag_busy_list
;
384 unsigned int nr_sorted
;
385 unsigned int in_flight
;
390 unsigned int sg_timeout
;
391 unsigned int sg_reserved_size
;
393 #ifdef CONFIG_BLK_DEV_IO_TRACE
394 struct blk_trace
*blk_trace
;
397 * reserved for flush operations
399 unsigned int ordered
, next_ordered
, ordseq
;
400 int orderr
, ordcolor
;
401 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
402 struct request
*orig_bar_rq
;
404 struct mutex sysfs_lock
;
406 #if defined(CONFIG_BLK_DEV_BSG)
407 struct bsg_class_device bsg_dev
;
409 struct blk_cmd_filter cmd_filter
;
412 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
413 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
414 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
415 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
416 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
417 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
418 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
419 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
420 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
421 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
422 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
424 static inline int queue_is_locked(struct request_queue
*q
)
427 spinlock_t
*lock
= q
->queue_lock
;
428 return lock
&& spin_is_locked(lock
);
434 static inline void queue_flag_set_unlocked(unsigned int flag
,
435 struct request_queue
*q
)
437 __set_bit(flag
, &q
->queue_flags
);
440 static inline int queue_flag_test_and_clear(unsigned int flag
,
441 struct request_queue
*q
)
443 WARN_ON_ONCE(!queue_is_locked(q
));
445 if (test_bit(flag
, &q
->queue_flags
)) {
446 __clear_bit(flag
, &q
->queue_flags
);
453 static inline int queue_flag_test_and_set(unsigned int flag
,
454 struct request_queue
*q
)
456 WARN_ON_ONCE(!queue_is_locked(q
));
458 if (!test_bit(flag
, &q
->queue_flags
)) {
459 __set_bit(flag
, &q
->queue_flags
);
466 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
468 WARN_ON_ONCE(!queue_is_locked(q
));
469 __set_bit(flag
, &q
->queue_flags
);
472 static inline void queue_flag_clear_unlocked(unsigned int flag
,
473 struct request_queue
*q
)
475 __clear_bit(flag
, &q
->queue_flags
);
478 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
480 WARN_ON_ONCE(!queue_is_locked(q
));
481 __clear_bit(flag
, &q
->queue_flags
);
486 * Hardbarrier is supported with one of the following methods.
488 * NONE : hardbarrier unsupported
489 * DRAIN : ordering by draining is enough
490 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
491 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
492 * TAG : ordering by tag is enough
493 * TAG_FLUSH : ordering by tag w/ pre and post flushes
494 * TAG_FUA : ordering by tag w/ pre flush and FUA write
496 QUEUE_ORDERED_NONE
= 0x00,
497 QUEUE_ORDERED_DRAIN
= 0x01,
498 QUEUE_ORDERED_TAG
= 0x02,
500 QUEUE_ORDERED_PREFLUSH
= 0x10,
501 QUEUE_ORDERED_POSTFLUSH
= 0x20,
502 QUEUE_ORDERED_FUA
= 0x40,
504 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
505 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
506 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
507 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
508 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
509 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
510 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
511 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
514 * Ordered operation sequence
516 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
517 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
518 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
519 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
520 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
521 QUEUE_ORDSEQ_DONE
= 0x20,
524 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
525 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
526 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
527 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
528 #define blk_queue_flushing(q) ((q)->ordseq)
530 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
531 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
532 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
533 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
535 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
536 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
538 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
540 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
541 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
542 #define blk_pm_request(rq) \
543 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
545 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
546 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
547 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
548 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
549 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
550 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
551 /* rq->queuelist of dequeued request must be list_empty() */
552 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
554 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
556 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
559 * We regard a request as sync, if it's a READ or a SYNC write.
561 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
562 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
564 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
567 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
568 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
571 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
574 queue_flag_set(QUEUE_FLAG_READFULL
, q
);
576 queue_flag_set(QUEUE_FLAG_WRITEFULL
, q
);
579 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
582 queue_flag_clear(QUEUE_FLAG_READFULL
, q
);
584 queue_flag_clear(QUEUE_FLAG_WRITEFULL
, q
);
589 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
590 * it already be started by driver.
592 #define RQ_NOMERGE_FLAGS \
593 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
594 #define rq_mergeable(rq) \
595 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
596 (blk_discard_rq(rq) || blk_fs_request((rq))))
599 * q->prep_rq_fn return values
601 #define BLKPREP_OK 0 /* serve it */
602 #define BLKPREP_KILL 1 /* fatal error, kill */
603 #define BLKPREP_DEFER 2 /* leave on queue */
605 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
608 * standard bounce addresses:
610 * BLK_BOUNCE_HIGH : bounce all highmem pages
611 * BLK_BOUNCE_ANY : don't bounce anything
612 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
615 #if BITS_PER_LONG == 32
616 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
618 #define BLK_BOUNCE_HIGH -1ULL
620 #define BLK_BOUNCE_ANY (-1ULL)
621 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
624 * default timeout for SG_IO if none specified
626 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
629 extern int init_emergency_isa_pool(void);
630 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
632 static inline int init_emergency_isa_pool(void)
636 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
639 #endif /* CONFIG_MMU */
641 struct req_iterator
{
646 /* This should not be used directly - use rq_for_each_segment */
647 #define __rq_for_each_bio(_bio, rq) \
649 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
651 #define rq_for_each_segment(bvl, _rq, _iter) \
652 __rq_for_each_bio(_iter.bio, _rq) \
653 bio_for_each_segment(bvl, _iter.bio, _iter.i)
655 #define rq_iter_last(rq, _iter) \
656 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
658 extern int blk_register_queue(struct gendisk
*disk
);
659 extern void blk_unregister_queue(struct gendisk
*disk
);
660 extern void register_disk(struct gendisk
*dev
);
661 extern void generic_make_request(struct bio
*bio
);
662 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
663 extern void blk_put_request(struct request
*);
664 extern void __blk_put_request(struct request_queue
*, struct request
*);
665 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
666 extern void blk_insert_request(struct request_queue
*, struct request
*, int, void *);
667 extern void blk_requeue_request(struct request_queue
*, struct request
*);
668 extern void blk_plug_device(struct request_queue
*);
669 extern void blk_plug_device_unlocked(struct request_queue
*);
670 extern int blk_remove_plug(struct request_queue
*);
671 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
672 extern int scsi_cmd_ioctl(struct file
*, struct request_queue
*,
673 struct gendisk
*, unsigned int, void __user
*);
674 extern int sg_scsi_ioctl(struct file
*, struct request_queue
*,
675 struct gendisk
*, struct scsi_ioctl_command __user
*);
678 * Temporary export, until SCSI gets fixed up.
680 extern int blk_rq_append_bio(struct request_queue
*q
, struct request
*rq
,
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 rw
)
690 clear_bdi_congested(&q
->backing_dev_info
, rw
);
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 rw
)
699 set_bdi_congested(&q
->backing_dev_info
, rw
);
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
*);
707 extern void blk_run_queue(struct request_queue
*);
708 extern void blk_start_queueing(struct request_queue
*);
709 extern int blk_rq_map_user(struct request_queue
*, struct request
*, void __user
*, unsigned long);
710 extern int blk_rq_unmap_user(struct bio
*);
711 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
712 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
713 struct sg_iovec
*, int, unsigned int);
714 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
715 struct request
*, int);
716 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
717 struct request
*, int, rq_end_io_fn
*);
718 extern void blk_unplug(struct request_queue
*q
);
720 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
722 return bdev
->bd_disk
->queue
;
725 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
728 if (bdi
&& bdi
->unplug_io_fn
)
729 bdi
->unplug_io_fn(bdi
, page
);
732 static inline void blk_run_address_space(struct address_space
*mapping
)
735 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
739 * blk_end_request() and friends.
740 * __blk_end_request() and end_request() must be called with
741 * the request queue spinlock acquired.
743 * Several drivers define their own end_request and call
744 * blk_end_request() for parts of the original function.
745 * This prevents code duplication in drivers.
747 extern int blk_end_request(struct request
*rq
, int error
,
748 unsigned int nr_bytes
);
749 extern int __blk_end_request(struct request
*rq
, int error
,
750 unsigned int nr_bytes
);
751 extern int blk_end_bidi_request(struct request
*rq
, int error
,
752 unsigned int nr_bytes
, unsigned int bidi_bytes
);
753 extern void end_request(struct request
*, int);
754 extern void end_queued_request(struct request
*, int);
755 extern void end_dequeued_request(struct request
*, int);
756 extern int blk_end_request_callback(struct request
*rq
, int error
,
757 unsigned int nr_bytes
,
758 int (drv_callback
)(struct request
*));
759 extern void blk_complete_request(struct request
*);
762 * blk_end_request() takes bytes instead of sectors as a complete size.
763 * blk_rq_bytes() returns bytes left to complete in the entire request.
764 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
766 extern unsigned int blk_rq_bytes(struct request
*rq
);
767 extern unsigned int blk_rq_cur_bytes(struct request
*rq
);
769 static inline void blkdev_dequeue_request(struct request
*req
)
771 elv_dequeue_request(req
->q
, req
);
775 * Access functions for manipulating queue properties
777 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
778 spinlock_t
*lock
, int node_id
);
779 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
780 extern void blk_cleanup_queue(struct request_queue
*);
781 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
782 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
783 extern void blk_queue_max_sectors(struct request_queue
*, unsigned int);
784 extern void blk_queue_max_phys_segments(struct request_queue
*, unsigned short);
785 extern void blk_queue_max_hw_segments(struct request_queue
*, unsigned short);
786 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
787 extern void blk_queue_hardsect_size(struct request_queue
*, unsigned short);
788 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
789 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
790 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
791 extern int blk_queue_dma_drain(struct request_queue
*q
,
792 dma_drain_needed_fn
*dma_drain_needed
,
793 void *buf
, unsigned int size
);
794 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
795 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
796 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
797 extern void blk_queue_dma_alignment(struct request_queue
*, int);
798 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
799 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
800 extern void blk_queue_set_discard(struct request_queue
*, prepare_discard_fn
*);
801 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
802 extern int blk_queue_ordered(struct request_queue
*, unsigned, prepare_flush_fn
*);
803 extern int blk_do_ordered(struct request_queue
*, struct request
**);
804 extern unsigned blk_ordered_cur_seq(struct request_queue
*);
805 extern unsigned blk_ordered_req_seq(struct request
*);
806 extern void blk_ordered_complete_seq(struct request_queue
*, unsigned, int);
808 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
809 extern void blk_dump_rq_flags(struct request
*, char *);
810 extern void generic_unplug_device(struct request_queue
*);
811 extern void __generic_unplug_device(struct request_queue
*);
812 extern long nr_blockdev_pages(void);
814 int blk_get_queue(struct request_queue
*);
815 struct request_queue
*blk_alloc_queue(gfp_t
);
816 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
817 extern void blk_put_queue(struct request_queue
*);
822 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
823 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
824 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
825 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
826 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
827 extern void blk_queue_free_tags(struct request_queue
*);
828 extern int blk_queue_resize_tags(struct request_queue
*, int);
829 extern void blk_queue_invalidate_tags(struct request_queue
*);
830 extern struct blk_queue_tag
*blk_init_tags(int);
831 extern void blk_free_tags(struct blk_queue_tag
*);
833 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
836 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
838 return bqt
->tag_index
[tag
];
841 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
842 extern int blkdev_issue_discard(struct block_device
*, sector_t sector
,
845 static inline int sb_issue_discard(struct super_block
*sb
,
846 sector_t block
, unsigned nr_blocks
)
848 block
<<= (sb
->s_blocksize_bits
- 9);
849 nr_blocks
<<= (sb
->s_blocksize_bits
- 9);
850 return blkdev_issue_discard(sb
->s_bdev
, block
, nr_blocks
);
854 * command filter functions
856 extern int blk_verify_command(struct blk_cmd_filter
*filter
,
857 unsigned char *cmd
, int has_write_perm
);
858 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter
*filter
);
860 #define MAX_PHYS_SEGMENTS 128
861 #define MAX_HW_SEGMENTS 128
862 #define SAFE_MAX_SECTORS 255
863 #define BLK_DEF_MAX_SECTORS 1024
865 #define MAX_SEGMENT_SIZE 65536
867 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
869 static inline int queue_hardsect_size(struct request_queue
*q
)
873 if (q
&& q
->hardsect_size
)
874 retval
= q
->hardsect_size
;
879 static inline int bdev_hardsect_size(struct block_device
*bdev
)
881 return queue_hardsect_size(bdev_get_queue(bdev
));
884 static inline int queue_dma_alignment(struct request_queue
*q
)
886 return q
? q
->dma_alignment
: 511;
889 /* assumes size > 256 */
890 static inline unsigned int blksize_bits(unsigned int size
)
892 unsigned int bits
= 8;
896 } while (size
> 256);
900 static inline unsigned int block_size(struct block_device
*bdev
)
902 return bdev
->bd_block_size
;
905 typedef struct {struct page
*v
;} Sector
;
907 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
909 static inline void put_dev_sector(Sector p
)
911 page_cache_release(p
.v
);
915 int kblockd_schedule_work(struct work_struct
*work
);
916 void kblockd_flush_work(struct work_struct
*work
);
918 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
919 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
920 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
921 MODULE_ALIAS("block-major-" __stringify(major) "-*")
923 #if defined(CONFIG_BLK_DEV_INTEGRITY)
925 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
926 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
928 struct blk_integrity_exchg
{
932 unsigned int data_size
;
933 unsigned short sector_size
;
934 const char *disk_name
;
937 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
938 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
939 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
940 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
942 struct blk_integrity
{
943 integrity_gen_fn
*generate_fn
;
944 integrity_vrfy_fn
*verify_fn
;
945 integrity_set_tag_fn
*set_tag_fn
;
946 integrity_get_tag_fn
*get_tag_fn
;
948 unsigned short flags
;
949 unsigned short tuple_size
;
950 unsigned short sector_size
;
951 unsigned short tag_size
;
958 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
959 extern void blk_integrity_unregister(struct gendisk
*);
960 extern int blk_integrity_compare(struct block_device
*, struct block_device
*);
961 extern int blk_rq_map_integrity_sg(struct request
*, struct scatterlist
*);
962 extern int blk_rq_count_integrity_sg(struct request
*);
964 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity
*bi
)
967 return bi
->tuple_size
;
972 static inline struct blk_integrity
*bdev_get_integrity(struct block_device
*bdev
)
974 return bdev
->bd_disk
->integrity
;
977 static inline unsigned int bdev_get_tag_size(struct block_device
*bdev
)
979 struct blk_integrity
*bi
= bdev_get_integrity(bdev
);
987 static inline int bdev_integrity_enabled(struct block_device
*bdev
, int rw
)
989 struct blk_integrity
*bi
= bdev_get_integrity(bdev
);
994 if (rw
== READ
&& bi
->verify_fn
!= NULL
&&
995 (bi
->flags
& INTEGRITY_FLAG_READ
))
998 if (rw
== WRITE
&& bi
->generate_fn
!= NULL
&&
999 (bi
->flags
& INTEGRITY_FLAG_WRITE
))
1005 static inline int blk_integrity_rq(struct request
*rq
)
1007 if (rq
->bio
== NULL
)
1010 return bio_integrity(rq
->bio
);
1013 #else /* CONFIG_BLK_DEV_INTEGRITY */
1015 #define blk_integrity_rq(rq) (0)
1016 #define blk_rq_count_integrity_sg(a) (0)
1017 #define blk_rq_map_integrity_sg(a, b) (0)
1018 #define bdev_get_integrity(a) (0)
1019 #define bdev_get_tag_size(a) (0)
1020 #define blk_integrity_compare(a, b) (0)
1021 #define blk_integrity_register(a, b) (0)
1022 #define blk_integrity_unregister(a) do { } while (0);
1024 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1026 #else /* CONFIG_BLOCK */
1028 * stubs for when the block layer is configured out
1030 #define buffer_heads_over_limit 0
1032 static inline long nr_blockdev_pages(void)
1037 #endif /* CONFIG_BLOCK */