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 typedef struct elevator_queue elevator_t
;
30 struct request_pm_state
;
35 #define BLKDEV_MIN_RQ 4
36 #define BLKDEV_MAX_RQ 128 /* Default maximum */
39 typedef void (rq_end_io_fn
)(struct request
*, int);
46 wait_queue_head_t wait
[2];
50 * request command types
52 enum rq_cmd_type_bits
{
53 REQ_TYPE_FS
= 1, /* fs request */
54 REQ_TYPE_BLOCK_PC
, /* scsi command */
55 REQ_TYPE_SENSE
, /* sense request */
56 REQ_TYPE_PM_SUSPEND
, /* suspend request */
57 REQ_TYPE_PM_RESUME
, /* resume request */
58 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
59 REQ_TYPE_SPECIAL
, /* driver defined type */
60 REQ_TYPE_LINUX_BLOCK
, /* generic block layer message */
62 * for ATA/ATAPI devices. this really doesn't belong here, ide should
63 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
64 * private REQ_LB opcodes to differentiate what type of request this is
66 REQ_TYPE_ATA_TASKFILE
,
71 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
72 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
75 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
76 * typically to differentiate REQ_TYPE_SPECIAL requests.
80 REQ_LB_OP_EJECT
= 0x40, /* eject request */
81 REQ_LB_OP_FLUSH
= 0x41, /* flush request */
82 REQ_LB_OP_DISCARD
= 0x42, /* discard sectors */
86 * request type modified bits. first two bits match BIO_RW* bits, important
89 __REQ_RW
, /* not set, read. set, write */
90 __REQ_FAILFAST
, /* no low level driver retries */
91 __REQ_DISCARD
, /* request to discard sectors */
92 __REQ_SORTED
, /* elevator knows about this request */
93 __REQ_SOFTBARRIER
, /* may not be passed by ioscheduler */
94 __REQ_HARDBARRIER
, /* may not be passed by drive either */
95 __REQ_FUA
, /* forced unit access */
96 __REQ_NOMERGE
, /* don't touch this for merging */
97 __REQ_STARTED
, /* drive already may have started this one */
98 __REQ_DONTPREP
, /* don't call prep for this one */
99 __REQ_QUEUED
, /* uses queueing */
100 __REQ_ELVPRIV
, /* elevator private data attached */
101 __REQ_FAILED
, /* set if the request failed */
102 __REQ_QUIET
, /* don't worry about errors */
103 __REQ_PREEMPT
, /* set for "ide_preempt" requests */
104 __REQ_ORDERED_COLOR
, /* is before or after barrier */
105 __REQ_RW_SYNC
, /* request is sync (O_DIRECT) */
106 __REQ_ALLOCED
, /* request came from our alloc pool */
107 __REQ_RW_META
, /* metadata io request */
108 __REQ_COPY_USER
, /* contains copies of user pages */
109 __REQ_INTEGRITY
, /* integrity metadata has been remapped */
110 __REQ_NR_BITS
, /* stops here */
113 #define REQ_RW (1 << __REQ_RW)
114 #define REQ_DISCARD (1 << __REQ_DISCARD)
115 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
116 #define REQ_SORTED (1 << __REQ_SORTED)
117 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
118 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
119 #define REQ_FUA (1 << __REQ_FUA)
120 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
121 #define REQ_STARTED (1 << __REQ_STARTED)
122 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
123 #define REQ_QUEUED (1 << __REQ_QUEUED)
124 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
125 #define REQ_FAILED (1 << __REQ_FAILED)
126 #define REQ_QUIET (1 << __REQ_QUIET)
127 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
128 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
129 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
130 #define REQ_ALLOCED (1 << __REQ_ALLOCED)
131 #define REQ_RW_META (1 << __REQ_RW_META)
132 #define REQ_COPY_USER (1 << __REQ_COPY_USER)
133 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
135 #define BLK_MAX_CDB 16
138 * try to put the fields that are referenced together in the same cacheline.
139 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
143 struct list_head queuelist
;
144 struct call_single_data csd
;
147 struct request_queue
*q
;
149 unsigned int cmd_flags
;
150 enum rq_cmd_type_bits cmd_type
;
151 unsigned long atomic_flags
;
153 /* Maintain bio traversal state for part by part I/O submission.
154 * hard_* are block layer internals, no driver should touch them!
157 sector_t sector
; /* next sector to submit */
158 sector_t hard_sector
; /* next sector to complete */
159 unsigned long nr_sectors
; /* no. of sectors left to submit */
160 unsigned long hard_nr_sectors
; /* no. of sectors left to complete */
161 /* no. of sectors left to submit in the current segment */
162 unsigned int current_nr_sectors
;
164 /* no. of sectors left to complete in the current segment */
165 unsigned int hard_cur_sectors
;
170 struct hlist_node hash
; /* merge hash */
172 * The rb_node is only used inside the io scheduler, requests
173 * are pruned when moved to the dispatch queue. So let the
174 * completion_data share space with the rb_node.
177 struct rb_node rb_node
; /* sort/lookup */
178 void *completion_data
;
182 * two pointers are available for the IO schedulers, if they need
183 * more they have to dynamically allocate it.
185 void *elevator_private
;
186 void *elevator_private2
;
188 struct gendisk
*rq_disk
;
189 unsigned long start_time
;
191 /* Number of scatter-gather DMA addr+len pairs after
192 * physical address coalescing is performed.
194 unsigned short nr_phys_segments
;
196 unsigned short ioprio
;
207 * when request is used as a packet command carrier
209 unsigned short cmd_len
;
210 unsigned char __cmd
[BLK_MAX_CDB
];
213 unsigned int data_len
;
214 unsigned int extra_len
; /* length of alignment and padding */
215 unsigned int sense_len
;
219 unsigned long deadline
;
220 struct list_head timeout_list
;
221 unsigned int timeout
;
225 * completion callback.
227 rq_end_io_fn
*end_io
;
231 struct request
*next_rq
;
234 static inline unsigned short req_get_ioprio(struct request
*req
)
240 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
241 * requests. Some step values could eventually be made generic.
243 struct request_pm_state
245 /* PM state machine step value, currently driver specific */
247 /* requested PM state value (S1, S2, S3, S4, ...) */
249 void* data
; /* for driver use */
252 #include <linux/elevator.h>
254 typedef void (request_fn_proc
) (struct request_queue
*q
);
255 typedef int (make_request_fn
) (struct request_queue
*q
, struct bio
*bio
);
256 typedef int (prep_rq_fn
) (struct request_queue
*, struct request
*);
257 typedef void (unplug_fn
) (struct request_queue
*);
258 typedef int (prepare_discard_fn
) (struct request_queue
*, struct request
*);
261 struct bvec_merge_data
{
262 struct block_device
*bi_bdev
;
267 typedef int (merge_bvec_fn
) (struct request_queue
*, struct bvec_merge_data
*,
269 typedef void (prepare_flush_fn
) (struct request_queue
*, struct request
*);
270 typedef void (softirq_done_fn
)(struct request
*);
271 typedef int (dma_drain_needed_fn
)(struct request
*);
273 enum blk_eh_timer_return
{
279 typedef enum blk_eh_timer_return (rq_timed_out_fn
)(struct request
*);
281 enum blk_queue_state
{
286 struct blk_queue_tag
{
287 struct request
**tag_index
; /* map of busy tags */
288 unsigned long *tag_map
; /* bit map of free/busy tags */
289 int busy
; /* current depth */
290 int max_depth
; /* what we will send to device */
291 int real_max_depth
; /* what the array can hold */
292 atomic_t refcnt
; /* map can be shared */
295 #define BLK_SCSI_MAX_CMDS (256)
296 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
298 struct blk_cmd_filter
{
299 unsigned long read_ok
[BLK_SCSI_CMD_PER_LONG
];
300 unsigned long write_ok
[BLK_SCSI_CMD_PER_LONG
];
307 * Together with queue_head for cacheline sharing
309 struct list_head queue_head
;
310 struct request
*last_merge
;
311 elevator_t
*elevator
;
314 * the queue request freelist, one for reads and one for writes
316 struct request_list rq
;
318 request_fn_proc
*request_fn
;
319 make_request_fn
*make_request_fn
;
320 prep_rq_fn
*prep_rq_fn
;
321 unplug_fn
*unplug_fn
;
322 prepare_discard_fn
*prepare_discard_fn
;
323 merge_bvec_fn
*merge_bvec_fn
;
324 prepare_flush_fn
*prepare_flush_fn
;
325 softirq_done_fn
*softirq_done_fn
;
326 rq_timed_out_fn
*rq_timed_out_fn
;
327 dma_drain_needed_fn
*dma_drain_needed
;
330 * Dispatch queue sorting
333 struct request
*boundary_rq
;
336 * Auto-unplugging state
338 struct timer_list unplug_timer
;
339 int unplug_thresh
; /* After this many requests */
340 unsigned long unplug_delay
; /* After this many jiffies */
341 struct work_struct unplug_work
;
343 struct backing_dev_info backing_dev_info
;
346 * The queue owner gets to use this for whatever they like.
347 * ll_rw_blk doesn't touch it.
352 * queue needs bounce pages for pages above this limit
354 unsigned long bounce_pfn
;
358 * various queue flags, see QUEUE_* below
360 unsigned long queue_flags
;
363 * protects queue structures from reentrancy. ->__queue_lock should
364 * _never_ be used directly, it is queue private. always use
367 spinlock_t __queue_lock
;
368 spinlock_t
*queue_lock
;
378 unsigned long nr_requests
; /* Max # of requests */
379 unsigned int nr_congestion_on
;
380 unsigned int nr_congestion_off
;
381 unsigned int nr_batching
;
383 unsigned int max_sectors
;
384 unsigned int max_hw_sectors
;
385 unsigned short max_phys_segments
;
386 unsigned short max_hw_segments
;
387 unsigned short hardsect_size
;
388 unsigned int max_segment_size
;
390 unsigned long seg_boundary_mask
;
391 void *dma_drain_buffer
;
392 unsigned int dma_drain_size
;
393 unsigned int dma_pad_mask
;
394 unsigned int dma_alignment
;
396 struct blk_queue_tag
*queue_tags
;
397 struct list_head tag_busy_list
;
399 unsigned int nr_sorted
;
400 unsigned int in_flight
;
402 unsigned int rq_timeout
;
403 struct timer_list timeout
;
404 struct list_head timeout_list
;
409 unsigned int sg_timeout
;
410 unsigned int sg_reserved_size
;
412 #ifdef CONFIG_BLK_DEV_IO_TRACE
413 struct blk_trace
*blk_trace
;
416 * reserved for flush operations
418 unsigned int ordered
, next_ordered
, ordseq
;
419 int orderr
, ordcolor
;
420 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
421 struct request
*orig_bar_rq
;
423 struct mutex sysfs_lock
;
425 #if defined(CONFIG_BLK_DEV_BSG)
426 struct bsg_class_device bsg_dev
;
428 struct blk_cmd_filter cmd_filter
;
431 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
432 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
433 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
434 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
435 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
436 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
437 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
438 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
439 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
440 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
441 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
442 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
443 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
445 static inline int queue_is_locked(struct request_queue
*q
)
448 spinlock_t
*lock
= q
->queue_lock
;
449 return lock
&& spin_is_locked(lock
);
455 static inline void queue_flag_set_unlocked(unsigned int flag
,
456 struct request_queue
*q
)
458 __set_bit(flag
, &q
->queue_flags
);
461 static inline int queue_flag_test_and_clear(unsigned int flag
,
462 struct request_queue
*q
)
464 WARN_ON_ONCE(!queue_is_locked(q
));
466 if (test_bit(flag
, &q
->queue_flags
)) {
467 __clear_bit(flag
, &q
->queue_flags
);
474 static inline int queue_flag_test_and_set(unsigned int flag
,
475 struct request_queue
*q
)
477 WARN_ON_ONCE(!queue_is_locked(q
));
479 if (!test_bit(flag
, &q
->queue_flags
)) {
480 __set_bit(flag
, &q
->queue_flags
);
487 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
489 WARN_ON_ONCE(!queue_is_locked(q
));
490 __set_bit(flag
, &q
->queue_flags
);
493 static inline void queue_flag_clear_unlocked(unsigned int flag
,
494 struct request_queue
*q
)
496 __clear_bit(flag
, &q
->queue_flags
);
499 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
501 WARN_ON_ONCE(!queue_is_locked(q
));
502 __clear_bit(flag
, &q
->queue_flags
);
507 * Hardbarrier is supported with one of the following methods.
509 * NONE : hardbarrier unsupported
510 * DRAIN : ordering by draining is enough
511 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
512 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
513 * TAG : ordering by tag is enough
514 * TAG_FLUSH : ordering by tag w/ pre and post flushes
515 * TAG_FUA : ordering by tag w/ pre flush and FUA write
517 QUEUE_ORDERED_NONE
= 0x00,
518 QUEUE_ORDERED_DRAIN
= 0x01,
519 QUEUE_ORDERED_TAG
= 0x02,
521 QUEUE_ORDERED_PREFLUSH
= 0x10,
522 QUEUE_ORDERED_POSTFLUSH
= 0x20,
523 QUEUE_ORDERED_FUA
= 0x40,
525 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
526 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
527 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
528 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
529 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
530 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
531 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
532 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
535 * Ordered operation sequence
537 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
538 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
539 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
540 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
541 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
542 QUEUE_ORDSEQ_DONE
= 0x20,
545 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
546 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
547 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
548 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
549 #define blk_queue_flushing(q) ((q)->ordseq)
551 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
552 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
553 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
554 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
556 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
557 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
559 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
561 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
562 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
563 #define blk_pm_request(rq) \
564 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
566 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
567 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
568 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
569 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
570 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
571 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
572 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
573 /* rq->queuelist of dequeued request must be list_empty() */
574 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
576 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
578 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
581 * We regard a request as sync, if it's a READ or a SYNC write.
583 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
584 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
586 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
589 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
590 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
593 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
596 queue_flag_set(QUEUE_FLAG_READFULL
, q
);
598 queue_flag_set(QUEUE_FLAG_WRITEFULL
, q
);
601 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
604 queue_flag_clear(QUEUE_FLAG_READFULL
, q
);
606 queue_flag_clear(QUEUE_FLAG_WRITEFULL
, q
);
611 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
612 * it already be started by driver.
614 #define RQ_NOMERGE_FLAGS \
615 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
616 #define rq_mergeable(rq) \
617 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
618 (blk_discard_rq(rq) || blk_fs_request((rq))))
621 * q->prep_rq_fn return values
623 #define BLKPREP_OK 0 /* serve it */
624 #define BLKPREP_KILL 1 /* fatal error, kill */
625 #define BLKPREP_DEFER 2 /* leave on queue */
627 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
630 * standard bounce addresses:
632 * BLK_BOUNCE_HIGH : bounce all highmem pages
633 * BLK_BOUNCE_ANY : don't bounce anything
634 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
637 #if BITS_PER_LONG == 32
638 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
640 #define BLK_BOUNCE_HIGH -1ULL
642 #define BLK_BOUNCE_ANY (-1ULL)
643 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
646 * default timeout for SG_IO if none specified
648 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
651 extern int init_emergency_isa_pool(void);
652 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
654 static inline int init_emergency_isa_pool(void)
658 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
661 #endif /* CONFIG_MMU */
669 struct req_iterator
{
674 /* This should not be used directly - use rq_for_each_segment */
675 #define __rq_for_each_bio(_bio, rq) \
677 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
679 #define rq_for_each_segment(bvl, _rq, _iter) \
680 __rq_for_each_bio(_iter.bio, _rq) \
681 bio_for_each_segment(bvl, _iter.bio, _iter.i)
683 #define rq_iter_last(rq, _iter) \
684 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
686 extern int blk_register_queue(struct gendisk
*disk
);
687 extern void blk_unregister_queue(struct gendisk
*disk
);
688 extern void register_disk(struct gendisk
*dev
);
689 extern void generic_make_request(struct bio
*bio
);
690 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
691 extern void blk_put_request(struct request
*);
692 extern void __blk_put_request(struct request_queue
*, struct request
*);
693 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
694 extern void blk_insert_request(struct request_queue
*, struct request
*, int, void *);
695 extern void blk_requeue_request(struct request_queue
*, struct request
*);
696 extern void blk_plug_device(struct request_queue
*);
697 extern void blk_plug_device_unlocked(struct request_queue
*);
698 extern int blk_remove_plug(struct request_queue
*);
699 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
700 extern int scsi_cmd_ioctl(struct file
*, struct request_queue
*,
701 struct gendisk
*, unsigned int, void __user
*);
702 extern int sg_scsi_ioctl(struct file
*, struct request_queue
*,
703 struct gendisk
*, struct scsi_ioctl_command __user
*);
706 * Temporary export, until SCSI gets fixed up.
708 extern int blk_rq_append_bio(struct request_queue
*q
, struct request
*rq
,
712 * A queue has just exitted congestion. Note this in the global counter of
713 * congested queues, and wake up anyone who was waiting for requests to be
716 static inline void blk_clear_queue_congested(struct request_queue
*q
, int rw
)
718 clear_bdi_congested(&q
->backing_dev_info
, rw
);
722 * A queue has just entered congestion. Flag that in the queue's VM-visible
723 * state flags and increment the global gounter of congested queues.
725 static inline void blk_set_queue_congested(struct request_queue
*q
, int rw
)
727 set_bdi_congested(&q
->backing_dev_info
, rw
);
730 extern void blk_start_queue(struct request_queue
*q
);
731 extern void blk_stop_queue(struct request_queue
*q
);
732 extern void blk_sync_queue(struct request_queue
*q
);
733 extern void __blk_stop_queue(struct request_queue
*q
);
734 extern void __blk_run_queue(struct request_queue
*);
735 extern void blk_run_queue(struct request_queue
*);
736 extern void blk_start_queueing(struct request_queue
*);
737 extern int blk_rq_map_user(struct request_queue
*, struct request
*,
738 struct rq_map_data
*, void __user
*, unsigned long,
740 extern int blk_rq_unmap_user(struct bio
*);
741 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
742 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
743 struct rq_map_data
*, struct sg_iovec
*, int,
744 unsigned int, gfp_t
);
745 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
746 struct request
*, int);
747 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
748 struct request
*, int, rq_end_io_fn
*);
749 extern void blk_unplug(struct request_queue
*q
);
751 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
753 return bdev
->bd_disk
->queue
;
756 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
759 if (bdi
&& bdi
->unplug_io_fn
)
760 bdi
->unplug_io_fn(bdi
, page
);
763 static inline void blk_run_address_space(struct address_space
*mapping
)
766 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
770 * blk_end_request() and friends.
771 * __blk_end_request() and end_request() must be called with
772 * the request queue spinlock acquired.
774 * Several drivers define their own end_request and call
775 * blk_end_request() for parts of the original function.
776 * This prevents code duplication in drivers.
778 extern int blk_end_request(struct request
*rq
, int error
,
779 unsigned int nr_bytes
);
780 extern int __blk_end_request(struct request
*rq
, int error
,
781 unsigned int nr_bytes
);
782 extern int blk_end_bidi_request(struct request
*rq
, int error
,
783 unsigned int nr_bytes
, unsigned int bidi_bytes
);
784 extern void end_request(struct request
*, int);
785 extern void end_queued_request(struct request
*, int);
786 extern void end_dequeued_request(struct request
*, int);
787 extern int blk_end_request_callback(struct request
*rq
, int error
,
788 unsigned int nr_bytes
,
789 int (drv_callback
)(struct request
*));
790 extern void blk_complete_request(struct request
*);
791 extern void __blk_complete_request(struct request
*);
792 extern void blk_abort_request(struct request
*);
793 extern void blk_abort_queue(struct request_queue
*);
794 extern void blk_update_request(struct request
*rq
, int error
,
795 unsigned int nr_bytes
);
798 * blk_end_request() takes bytes instead of sectors as a complete size.
799 * blk_rq_bytes() returns bytes left to complete in the entire request.
800 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
802 extern unsigned int blk_rq_bytes(struct request
*rq
);
803 extern unsigned int blk_rq_cur_bytes(struct request
*rq
);
805 static inline void blkdev_dequeue_request(struct request
*req
)
807 elv_dequeue_request(req
->q
, req
);
811 * Access functions for manipulating queue properties
813 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
814 spinlock_t
*lock
, int node_id
);
815 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
816 extern void blk_cleanup_queue(struct request_queue
*);
817 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
818 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
819 extern void blk_queue_max_sectors(struct request_queue
*, unsigned int);
820 extern void blk_queue_max_phys_segments(struct request_queue
*, unsigned short);
821 extern void blk_queue_max_hw_segments(struct request_queue
*, unsigned short);
822 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
823 extern void blk_queue_hardsect_size(struct request_queue
*, unsigned short);
824 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
825 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
826 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
827 extern int blk_queue_dma_drain(struct request_queue
*q
,
828 dma_drain_needed_fn
*dma_drain_needed
,
829 void *buf
, unsigned int size
);
830 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
831 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
832 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
833 extern void blk_queue_dma_alignment(struct request_queue
*, int);
834 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
835 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
836 extern void blk_queue_set_discard(struct request_queue
*, prepare_discard_fn
*);
837 extern void blk_queue_rq_timed_out(struct request_queue
*, rq_timed_out_fn
*);
838 extern void blk_queue_rq_timeout(struct request_queue
*, unsigned int);
839 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
840 extern int blk_queue_ordered(struct request_queue
*, unsigned, prepare_flush_fn
*);
841 extern int blk_do_ordered(struct request_queue
*, struct request
**);
842 extern unsigned blk_ordered_cur_seq(struct request_queue
*);
843 extern unsigned blk_ordered_req_seq(struct request
*);
844 extern void blk_ordered_complete_seq(struct request_queue
*, unsigned, int);
846 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
847 extern void blk_dump_rq_flags(struct request
*, char *);
848 extern void generic_unplug_device(struct request_queue
*);
849 extern void __generic_unplug_device(struct request_queue
*);
850 extern long nr_blockdev_pages(void);
852 int blk_get_queue(struct request_queue
*);
853 struct request_queue
*blk_alloc_queue(gfp_t
);
854 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
855 extern void blk_put_queue(struct request_queue
*);
860 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
861 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
862 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
863 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
864 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
865 extern void blk_queue_free_tags(struct request_queue
*);
866 extern int blk_queue_resize_tags(struct request_queue
*, int);
867 extern void blk_queue_invalidate_tags(struct request_queue
*);
868 extern struct blk_queue_tag
*blk_init_tags(int);
869 extern void blk_free_tags(struct blk_queue_tag
*);
871 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
874 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
876 return bqt
->tag_index
[tag
];
879 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
880 extern int blkdev_issue_discard(struct block_device
*,
881 sector_t sector
, sector_t nr_sects
, gfp_t
);
883 static inline int sb_issue_discard(struct super_block
*sb
,
884 sector_t block
, sector_t nr_blocks
)
886 block
<<= (sb
->s_blocksize_bits
- 9);
887 nr_blocks
<<= (sb
->s_blocksize_bits
- 9);
888 return blkdev_issue_discard(sb
->s_bdev
, block
, nr_blocks
, GFP_KERNEL
);
892 * command filter functions
894 extern int blk_verify_command(struct blk_cmd_filter
*filter
,
895 unsigned char *cmd
, int has_write_perm
);
896 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter
*filter
);
898 #define MAX_PHYS_SEGMENTS 128
899 #define MAX_HW_SEGMENTS 128
900 #define SAFE_MAX_SECTORS 255
901 #define BLK_DEF_MAX_SECTORS 1024
903 #define MAX_SEGMENT_SIZE 65536
905 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
907 static inline int queue_hardsect_size(struct request_queue
*q
)
911 if (q
&& q
->hardsect_size
)
912 retval
= q
->hardsect_size
;
917 static inline int bdev_hardsect_size(struct block_device
*bdev
)
919 return queue_hardsect_size(bdev_get_queue(bdev
));
922 static inline int queue_dma_alignment(struct request_queue
*q
)
924 return q
? q
->dma_alignment
: 511;
927 static inline int blk_rq_aligned(struct request_queue
*q
, void *addr
,
930 unsigned int alignment
= queue_dma_alignment(q
) | q
->dma_pad_mask
;
931 return !((unsigned long)addr
& alignment
) && !(len
& alignment
);
934 /* assumes size > 256 */
935 static inline unsigned int blksize_bits(unsigned int size
)
937 unsigned int bits
= 8;
941 } while (size
> 256);
945 static inline unsigned int block_size(struct block_device
*bdev
)
947 return bdev
->bd_block_size
;
950 typedef struct {struct page
*v
;} Sector
;
952 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
954 static inline void put_dev_sector(Sector p
)
956 page_cache_release(p
.v
);
960 int kblockd_schedule_work(struct request_queue
*q
, struct work_struct
*work
);
961 void kblockd_flush_work(struct work_struct
*work
);
963 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
964 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
965 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
966 MODULE_ALIAS("block-major-" __stringify(major) "-*")
968 #if defined(CONFIG_BLK_DEV_INTEGRITY)
970 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
971 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
973 struct blk_integrity_exchg
{
977 unsigned int data_size
;
978 unsigned short sector_size
;
979 const char *disk_name
;
982 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
983 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
984 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
985 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
987 struct blk_integrity
{
988 integrity_gen_fn
*generate_fn
;
989 integrity_vrfy_fn
*verify_fn
;
990 integrity_set_tag_fn
*set_tag_fn
;
991 integrity_get_tag_fn
*get_tag_fn
;
993 unsigned short flags
;
994 unsigned short tuple_size
;
995 unsigned short sector_size
;
996 unsigned short tag_size
;
1000 struct kobject kobj
;
1003 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
1004 extern void blk_integrity_unregister(struct gendisk
*);
1005 extern int blk_integrity_compare(struct block_device
*, struct block_device
*);
1006 extern int blk_rq_map_integrity_sg(struct request
*, struct scatterlist
*);
1007 extern int blk_rq_count_integrity_sg(struct request
*);
1009 static inline int blk_integrity_rq(struct request
*rq
)
1011 if (rq
->bio
== NULL
)
1014 return bio_integrity(rq
->bio
);
1017 #else /* CONFIG_BLK_DEV_INTEGRITY */
1019 #define blk_integrity_rq(rq) (0)
1020 #define blk_rq_count_integrity_sg(a) (0)
1021 #define blk_rq_map_integrity_sg(a, b) (0)
1022 #define blk_integrity_compare(a, b) (0)
1023 #define blk_integrity_register(a, b) (0)
1024 #define blk_integrity_unregister(a) do { } while (0);
1026 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1028 #else /* CONFIG_BLOCK */
1030 * stubs for when the block layer is configured out
1032 #define buffer_heads_over_limit 0
1034 static inline long nr_blockdev_pages(void)
1039 #endif /* CONFIG_BLOCK */