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
*);
272 typedef int (lld_busy_fn
) (struct request_queue
*q
);
274 enum blk_eh_timer_return
{
280 typedef enum blk_eh_timer_return (rq_timed_out_fn
)(struct request
*);
282 enum blk_queue_state
{
287 struct blk_queue_tag
{
288 struct request
**tag_index
; /* map of busy tags */
289 unsigned long *tag_map
; /* bit map of free/busy tags */
290 int busy
; /* current depth */
291 int max_depth
; /* what we will send to device */
292 int real_max_depth
; /* what the array can hold */
293 atomic_t refcnt
; /* map can be shared */
296 #define BLK_SCSI_MAX_CMDS (256)
297 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
299 struct blk_cmd_filter
{
300 unsigned long read_ok
[BLK_SCSI_CMD_PER_LONG
];
301 unsigned long write_ok
[BLK_SCSI_CMD_PER_LONG
];
308 * Together with queue_head for cacheline sharing
310 struct list_head queue_head
;
311 struct request
*last_merge
;
312 elevator_t
*elevator
;
315 * the queue request freelist, one for reads and one for writes
317 struct request_list rq
;
319 request_fn_proc
*request_fn
;
320 make_request_fn
*make_request_fn
;
321 prep_rq_fn
*prep_rq_fn
;
322 unplug_fn
*unplug_fn
;
323 prepare_discard_fn
*prepare_discard_fn
;
324 merge_bvec_fn
*merge_bvec_fn
;
325 prepare_flush_fn
*prepare_flush_fn
;
326 softirq_done_fn
*softirq_done_fn
;
327 rq_timed_out_fn
*rq_timed_out_fn
;
328 dma_drain_needed_fn
*dma_drain_needed
;
329 lld_busy_fn
*lld_busy_fn
;
332 * Dispatch queue sorting
335 struct request
*boundary_rq
;
338 * Auto-unplugging state
340 struct timer_list unplug_timer
;
341 int unplug_thresh
; /* After this many requests */
342 unsigned long unplug_delay
; /* After this many jiffies */
343 struct work_struct unplug_work
;
345 struct backing_dev_info backing_dev_info
;
348 * The queue owner gets to use this for whatever they like.
349 * ll_rw_blk doesn't touch it.
354 * queue needs bounce pages for pages above this limit
356 unsigned long bounce_pfn
;
360 * various queue flags, see QUEUE_* below
362 unsigned long queue_flags
;
365 * protects queue structures from reentrancy. ->__queue_lock should
366 * _never_ be used directly, it is queue private. always use
369 spinlock_t __queue_lock
;
370 spinlock_t
*queue_lock
;
380 unsigned long nr_requests
; /* Max # of requests */
381 unsigned int nr_congestion_on
;
382 unsigned int nr_congestion_off
;
383 unsigned int nr_batching
;
385 unsigned int max_sectors
;
386 unsigned int max_hw_sectors
;
387 unsigned short max_phys_segments
;
388 unsigned short max_hw_segments
;
389 unsigned short hardsect_size
;
390 unsigned int max_segment_size
;
392 unsigned long seg_boundary_mask
;
393 void *dma_drain_buffer
;
394 unsigned int dma_drain_size
;
395 unsigned int dma_pad_mask
;
396 unsigned int dma_alignment
;
398 struct blk_queue_tag
*queue_tags
;
399 struct list_head tag_busy_list
;
401 unsigned int nr_sorted
;
402 unsigned int in_flight
;
404 unsigned int rq_timeout
;
405 struct timer_list timeout
;
406 struct list_head timeout_list
;
411 unsigned int sg_timeout
;
412 unsigned int sg_reserved_size
;
414 #ifdef CONFIG_BLK_DEV_IO_TRACE
415 struct blk_trace
*blk_trace
;
418 * reserved for flush operations
420 unsigned int ordered
, next_ordered
, ordseq
;
421 int orderr
, ordcolor
;
422 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
423 struct request
*orig_bar_rq
;
425 struct mutex sysfs_lock
;
427 #if defined(CONFIG_BLK_DEV_BSG)
428 struct bsg_class_device bsg_dev
;
430 struct blk_cmd_filter cmd_filter
;
433 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
434 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
435 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
436 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
437 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
438 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
439 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
440 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
441 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
442 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
443 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
444 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
445 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
446 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
447 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
449 static inline int queue_is_locked(struct request_queue
*q
)
452 spinlock_t
*lock
= q
->queue_lock
;
453 return lock
&& spin_is_locked(lock
);
459 static inline void queue_flag_set_unlocked(unsigned int flag
,
460 struct request_queue
*q
)
462 __set_bit(flag
, &q
->queue_flags
);
465 static inline int queue_flag_test_and_clear(unsigned int flag
,
466 struct request_queue
*q
)
468 WARN_ON_ONCE(!queue_is_locked(q
));
470 if (test_bit(flag
, &q
->queue_flags
)) {
471 __clear_bit(flag
, &q
->queue_flags
);
478 static inline int queue_flag_test_and_set(unsigned int flag
,
479 struct request_queue
*q
)
481 WARN_ON_ONCE(!queue_is_locked(q
));
483 if (!test_bit(flag
, &q
->queue_flags
)) {
484 __set_bit(flag
, &q
->queue_flags
);
491 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
493 WARN_ON_ONCE(!queue_is_locked(q
));
494 __set_bit(flag
, &q
->queue_flags
);
497 static inline void queue_flag_clear_unlocked(unsigned int flag
,
498 struct request_queue
*q
)
500 __clear_bit(flag
, &q
->queue_flags
);
503 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
505 WARN_ON_ONCE(!queue_is_locked(q
));
506 __clear_bit(flag
, &q
->queue_flags
);
511 * Hardbarrier is supported with one of the following methods.
513 * NONE : hardbarrier unsupported
514 * DRAIN : ordering by draining is enough
515 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
516 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
517 * TAG : ordering by tag is enough
518 * TAG_FLUSH : ordering by tag w/ pre and post flushes
519 * TAG_FUA : ordering by tag w/ pre flush and FUA write
521 QUEUE_ORDERED_NONE
= 0x00,
522 QUEUE_ORDERED_DRAIN
= 0x01,
523 QUEUE_ORDERED_TAG
= 0x02,
525 QUEUE_ORDERED_PREFLUSH
= 0x10,
526 QUEUE_ORDERED_POSTFLUSH
= 0x20,
527 QUEUE_ORDERED_FUA
= 0x40,
529 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
530 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
531 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
532 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
533 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
534 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
535 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
536 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
539 * Ordered operation sequence
541 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
542 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
543 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
544 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
545 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
546 QUEUE_ORDSEQ_DONE
= 0x20,
549 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
550 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
551 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
552 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
553 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
554 #define blk_queue_flushing(q) ((q)->ordseq)
555 #define blk_queue_stackable(q) \
556 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
558 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
559 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
560 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
561 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
563 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
564 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
566 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
568 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
569 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
570 #define blk_pm_request(rq) \
571 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
573 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
574 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
575 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
576 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
577 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
578 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
579 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
580 /* rq->queuelist of dequeued request must be list_empty() */
581 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
583 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
585 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
588 * We regard a request as sync, if it's a READ or a SYNC write.
590 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
591 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
593 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
596 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
597 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
600 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
603 queue_flag_set(QUEUE_FLAG_READFULL
, q
);
605 queue_flag_set(QUEUE_FLAG_WRITEFULL
, q
);
608 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
611 queue_flag_clear(QUEUE_FLAG_READFULL
, q
);
613 queue_flag_clear(QUEUE_FLAG_WRITEFULL
, q
);
618 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
619 * it already be started by driver.
621 #define RQ_NOMERGE_FLAGS \
622 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
623 #define rq_mergeable(rq) \
624 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
625 (blk_discard_rq(rq) || blk_fs_request((rq))))
628 * q->prep_rq_fn return values
630 #define BLKPREP_OK 0 /* serve it */
631 #define BLKPREP_KILL 1 /* fatal error, kill */
632 #define BLKPREP_DEFER 2 /* leave on queue */
634 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
637 * standard bounce addresses:
639 * BLK_BOUNCE_HIGH : bounce all highmem pages
640 * BLK_BOUNCE_ANY : don't bounce anything
641 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
644 #if BITS_PER_LONG == 32
645 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
647 #define BLK_BOUNCE_HIGH -1ULL
649 #define BLK_BOUNCE_ANY (-1ULL)
650 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
653 * default timeout for SG_IO if none specified
655 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
658 extern int init_emergency_isa_pool(void);
659 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
661 static inline int init_emergency_isa_pool(void)
665 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
668 #endif /* CONFIG_MMU */
676 struct req_iterator
{
681 /* This should not be used directly - use rq_for_each_segment */
682 #define __rq_for_each_bio(_bio, rq) \
684 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
686 #define rq_for_each_segment(bvl, _rq, _iter) \
687 __rq_for_each_bio(_iter.bio, _rq) \
688 bio_for_each_segment(bvl, _iter.bio, _iter.i)
690 #define rq_iter_last(rq, _iter) \
691 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
693 extern int blk_register_queue(struct gendisk
*disk
);
694 extern void blk_unregister_queue(struct gendisk
*disk
);
695 extern void register_disk(struct gendisk
*dev
);
696 extern void generic_make_request(struct bio
*bio
);
697 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
698 extern void blk_put_request(struct request
*);
699 extern void __blk_put_request(struct request_queue
*, struct request
*);
700 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
701 extern void blk_insert_request(struct request_queue
*, struct request
*, int, void *);
702 extern void blk_requeue_request(struct request_queue
*, struct request
*);
703 extern int blk_rq_check_limits(struct request_queue
*q
, struct request
*rq
);
704 extern int blk_lld_busy(struct request_queue
*q
);
705 extern int blk_insert_cloned_request(struct request_queue
*q
,
707 extern void blk_plug_device(struct request_queue
*);
708 extern void blk_plug_device_unlocked(struct request_queue
*);
709 extern int blk_remove_plug(struct request_queue
*);
710 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
711 extern int scsi_cmd_ioctl(struct file
*, struct request_queue
*,
712 struct gendisk
*, unsigned int, void __user
*);
713 extern int sg_scsi_ioctl(struct file
*, struct request_queue
*,
714 struct gendisk
*, struct scsi_ioctl_command __user
*);
717 * Temporary export, until SCSI gets fixed up.
719 extern int blk_rq_append_bio(struct request_queue
*q
, struct request
*rq
,
723 * A queue has just exitted congestion. Note this in the global counter of
724 * congested queues, and wake up anyone who was waiting for requests to be
727 static inline void blk_clear_queue_congested(struct request_queue
*q
, int rw
)
729 clear_bdi_congested(&q
->backing_dev_info
, rw
);
733 * A queue has just entered congestion. Flag that in the queue's VM-visible
734 * state flags and increment the global gounter of congested queues.
736 static inline void blk_set_queue_congested(struct request_queue
*q
, int rw
)
738 set_bdi_congested(&q
->backing_dev_info
, rw
);
741 extern void blk_start_queue(struct request_queue
*q
);
742 extern void blk_stop_queue(struct request_queue
*q
);
743 extern void blk_sync_queue(struct request_queue
*q
);
744 extern void __blk_stop_queue(struct request_queue
*q
);
745 extern void __blk_run_queue(struct request_queue
*);
746 extern void blk_run_queue(struct request_queue
*);
747 extern void blk_start_queueing(struct request_queue
*);
748 extern int blk_rq_map_user(struct request_queue
*, struct request
*,
749 struct rq_map_data
*, void __user
*, unsigned long,
751 extern int blk_rq_unmap_user(struct bio
*);
752 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
753 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
754 struct rq_map_data
*, struct sg_iovec
*, int,
755 unsigned int, gfp_t
);
756 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
757 struct request
*, int);
758 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
759 struct request
*, int, rq_end_io_fn
*);
760 extern void blk_unplug(struct request_queue
*q
);
762 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
764 return bdev
->bd_disk
->queue
;
767 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
770 if (bdi
&& bdi
->unplug_io_fn
)
771 bdi
->unplug_io_fn(bdi
, page
);
774 static inline void blk_run_address_space(struct address_space
*mapping
)
777 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
781 * blk_end_request() and friends.
782 * __blk_end_request() and end_request() must be called with
783 * the request queue spinlock acquired.
785 * Several drivers define their own end_request and call
786 * blk_end_request() for parts of the original function.
787 * This prevents code duplication in drivers.
789 extern int blk_end_request(struct request
*rq
, int error
,
790 unsigned int nr_bytes
);
791 extern int __blk_end_request(struct request
*rq
, int error
,
792 unsigned int nr_bytes
);
793 extern int blk_end_bidi_request(struct request
*rq
, int error
,
794 unsigned int nr_bytes
, unsigned int bidi_bytes
);
795 extern void end_request(struct request
*, int);
796 extern int blk_end_request_callback(struct request
*rq
, int error
,
797 unsigned int nr_bytes
,
798 int (drv_callback
)(struct request
*));
799 extern void blk_complete_request(struct request
*);
800 extern void __blk_complete_request(struct request
*);
801 extern void blk_abort_request(struct request
*);
802 extern void blk_abort_queue(struct request_queue
*);
803 extern void blk_update_request(struct request
*rq
, int error
,
804 unsigned int nr_bytes
);
807 * blk_end_request() takes bytes instead of sectors as a complete size.
808 * blk_rq_bytes() returns bytes left to complete in the entire request.
809 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
811 extern unsigned int blk_rq_bytes(struct request
*rq
);
812 extern unsigned int blk_rq_cur_bytes(struct request
*rq
);
814 static inline void blkdev_dequeue_request(struct request
*req
)
816 elv_dequeue_request(req
->q
, req
);
820 * Access functions for manipulating queue properties
822 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
823 spinlock_t
*lock
, int node_id
);
824 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
825 extern void blk_cleanup_queue(struct request_queue
*);
826 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
827 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
828 extern void blk_queue_max_sectors(struct request_queue
*, unsigned int);
829 extern void blk_queue_max_phys_segments(struct request_queue
*, unsigned short);
830 extern void blk_queue_max_hw_segments(struct request_queue
*, unsigned short);
831 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
832 extern void blk_queue_hardsect_size(struct request_queue
*, unsigned short);
833 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
834 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
835 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
836 extern int blk_queue_dma_drain(struct request_queue
*q
,
837 dma_drain_needed_fn
*dma_drain_needed
,
838 void *buf
, unsigned int size
);
839 extern void blk_queue_lld_busy(struct request_queue
*q
, lld_busy_fn
*fn
);
840 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
841 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
842 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
843 extern void blk_queue_dma_alignment(struct request_queue
*, int);
844 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
845 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
846 extern void blk_queue_set_discard(struct request_queue
*, prepare_discard_fn
*);
847 extern void blk_queue_rq_timed_out(struct request_queue
*, rq_timed_out_fn
*);
848 extern void blk_queue_rq_timeout(struct request_queue
*, unsigned int);
849 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
850 extern int blk_queue_ordered(struct request_queue
*, unsigned, prepare_flush_fn
*);
851 extern int blk_do_ordered(struct request_queue
*, struct request
**);
852 extern unsigned blk_ordered_cur_seq(struct request_queue
*);
853 extern unsigned blk_ordered_req_seq(struct request
*);
854 extern void blk_ordered_complete_seq(struct request_queue
*, unsigned, int);
856 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
857 extern void blk_dump_rq_flags(struct request
*, char *);
858 extern void generic_unplug_device(struct request_queue
*);
859 extern void __generic_unplug_device(struct request_queue
*);
860 extern long nr_blockdev_pages(void);
862 int blk_get_queue(struct request_queue
*);
863 struct request_queue
*blk_alloc_queue(gfp_t
);
864 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
865 extern void blk_put_queue(struct request_queue
*);
870 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
871 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
872 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
873 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
874 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
875 extern void blk_queue_free_tags(struct request_queue
*);
876 extern int blk_queue_resize_tags(struct request_queue
*, int);
877 extern void blk_queue_invalidate_tags(struct request_queue
*);
878 extern struct blk_queue_tag
*blk_init_tags(int);
879 extern void blk_free_tags(struct blk_queue_tag
*);
881 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
884 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
886 return bqt
->tag_index
[tag
];
889 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
890 extern int blkdev_issue_discard(struct block_device
*,
891 sector_t sector
, sector_t nr_sects
, gfp_t
);
893 static inline int sb_issue_discard(struct super_block
*sb
,
894 sector_t block
, sector_t nr_blocks
)
896 block
<<= (sb
->s_blocksize_bits
- 9);
897 nr_blocks
<<= (sb
->s_blocksize_bits
- 9);
898 return blkdev_issue_discard(sb
->s_bdev
, block
, nr_blocks
, GFP_KERNEL
);
902 * command filter functions
904 extern int blk_verify_command(struct blk_cmd_filter
*filter
,
905 unsigned char *cmd
, int has_write_perm
);
906 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter
*filter
);
908 #define MAX_PHYS_SEGMENTS 128
909 #define MAX_HW_SEGMENTS 128
910 #define SAFE_MAX_SECTORS 255
911 #define BLK_DEF_MAX_SECTORS 1024
913 #define MAX_SEGMENT_SIZE 65536
915 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
917 static inline int queue_hardsect_size(struct request_queue
*q
)
921 if (q
&& q
->hardsect_size
)
922 retval
= q
->hardsect_size
;
927 static inline int bdev_hardsect_size(struct block_device
*bdev
)
929 return queue_hardsect_size(bdev_get_queue(bdev
));
932 static inline int queue_dma_alignment(struct request_queue
*q
)
934 return q
? q
->dma_alignment
: 511;
937 static inline int blk_rq_aligned(struct request_queue
*q
, void *addr
,
940 unsigned int alignment
= queue_dma_alignment(q
) | q
->dma_pad_mask
;
941 return !((unsigned long)addr
& alignment
) && !(len
& alignment
);
944 /* assumes size > 256 */
945 static inline unsigned int blksize_bits(unsigned int size
)
947 unsigned int bits
= 8;
951 } while (size
> 256);
955 static inline unsigned int block_size(struct block_device
*bdev
)
957 return bdev
->bd_block_size
;
960 typedef struct {struct page
*v
;} Sector
;
962 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
964 static inline void put_dev_sector(Sector p
)
966 page_cache_release(p
.v
);
970 int kblockd_schedule_work(struct request_queue
*q
, struct work_struct
*work
);
971 void kblockd_flush_work(struct work_struct
*work
);
973 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
974 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
975 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
976 MODULE_ALIAS("block-major-" __stringify(major) "-*")
978 #if defined(CONFIG_BLK_DEV_INTEGRITY)
980 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
981 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
983 struct blk_integrity_exchg
{
987 unsigned int data_size
;
988 unsigned short sector_size
;
989 const char *disk_name
;
992 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
993 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
994 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
995 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
997 struct blk_integrity
{
998 integrity_gen_fn
*generate_fn
;
999 integrity_vrfy_fn
*verify_fn
;
1000 integrity_set_tag_fn
*set_tag_fn
;
1001 integrity_get_tag_fn
*get_tag_fn
;
1003 unsigned short flags
;
1004 unsigned short tuple_size
;
1005 unsigned short sector_size
;
1006 unsigned short tag_size
;
1010 struct kobject kobj
;
1013 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
1014 extern void blk_integrity_unregister(struct gendisk
*);
1015 extern int blk_integrity_compare(struct block_device
*, struct block_device
*);
1016 extern int blk_rq_map_integrity_sg(struct request
*, struct scatterlist
*);
1017 extern int blk_rq_count_integrity_sg(struct request
*);
1020 struct blk_integrity
*bdev_get_integrity(struct block_device
*bdev
)
1022 return bdev
->bd_disk
->integrity
;
1025 static inline int blk_integrity_rq(struct request
*rq
)
1027 if (rq
->bio
== NULL
)
1030 return bio_integrity(rq
->bio
);
1033 #else /* CONFIG_BLK_DEV_INTEGRITY */
1035 #define blk_integrity_rq(rq) (0)
1036 #define blk_rq_count_integrity_sg(a) (0)
1037 #define blk_rq_map_integrity_sg(a, b) (0)
1038 #define bdev_get_integrity(a) (0)
1039 #define blk_integrity_compare(a, b) (0)
1040 #define blk_integrity_register(a, b) (0)
1041 #define blk_integrity_unregister(a) do { } while (0);
1043 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1045 #else /* CONFIG_BLOCK */
1047 * stubs for when the block layer is configured out
1049 #define buffer_heads_over_limit 0
1051 static inline long nr_blockdev_pages(void)
1056 #endif /* CONFIG_BLOCK */