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>
20 #include <linux/smp.h>
22 #include <asm/scatterlist.h>
24 struct scsi_ioctl_command
;
27 struct elevator_queue
;
28 typedef struct elevator_queue elevator_t
;
29 struct request_pm_state
;
34 #define BLKDEV_MIN_RQ 4
35 #define BLKDEV_MAX_RQ 128 /* Default maximum */
38 typedef void (rq_end_io_fn
)(struct request
*, int);
45 wait_queue_head_t wait
[2];
49 * request command types
51 enum rq_cmd_type_bits
{
52 REQ_TYPE_FS
= 1, /* fs request */
53 REQ_TYPE_BLOCK_PC
, /* scsi command */
54 REQ_TYPE_SENSE
, /* sense request */
55 REQ_TYPE_PM_SUSPEND
, /* suspend request */
56 REQ_TYPE_PM_RESUME
, /* resume request */
57 REQ_TYPE_PM_SHUTDOWN
, /* shutdown request */
58 REQ_TYPE_SPECIAL
, /* driver defined type */
59 REQ_TYPE_LINUX_BLOCK
, /* generic block layer message */
61 * for ATA/ATAPI devices. this really doesn't belong here, ide should
62 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
63 * private REQ_LB opcodes to differentiate what type of request this is
65 REQ_TYPE_ATA_TASKFILE
,
70 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
71 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
74 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
75 * typically to differentiate REQ_TYPE_SPECIAL requests.
79 REQ_LB_OP_EJECT
= 0x40, /* eject request */
80 REQ_LB_OP_FLUSH
= 0x41, /* flush request */
81 REQ_LB_OP_DISCARD
= 0x42, /* discard sectors */
85 * request type modified bits. first two bits match BIO_RW* bits, important
88 __REQ_RW
, /* not set, read. set, write */
89 __REQ_FAILFAST
, /* no low level driver retries */
90 __REQ_DISCARD
, /* request to discard sectors */
91 __REQ_SORTED
, /* elevator knows about this request */
92 __REQ_SOFTBARRIER
, /* may not be passed by ioscheduler */
93 __REQ_HARDBARRIER
, /* may not be passed by drive either */
94 __REQ_FUA
, /* forced unit access */
95 __REQ_NOMERGE
, /* don't touch this for merging */
96 __REQ_STARTED
, /* drive already may have started this one */
97 __REQ_DONTPREP
, /* don't call prep for this one */
98 __REQ_QUEUED
, /* uses queueing */
99 __REQ_ELVPRIV
, /* elevator private data attached */
100 __REQ_FAILED
, /* set if the request failed */
101 __REQ_QUIET
, /* don't worry about errors */
102 __REQ_PREEMPT
, /* set for "ide_preempt" requests */
103 __REQ_ORDERED_COLOR
, /* is before or after barrier */
104 __REQ_RW_SYNC
, /* request is sync (O_DIRECT) */
105 __REQ_ALLOCED
, /* request came from our alloc pool */
106 __REQ_RW_META
, /* metadata io request */
107 __REQ_COPY_USER
, /* contains copies of user pages */
108 __REQ_INTEGRITY
, /* integrity metadata has been remapped */
109 __REQ_NR_BITS
, /* stops here */
112 #define REQ_RW (1 << __REQ_RW)
113 #define REQ_DISCARD (1 << __REQ_DISCARD)
114 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
115 #define REQ_SORTED (1 << __REQ_SORTED)
116 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
117 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
118 #define REQ_FUA (1 << __REQ_FUA)
119 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
120 #define REQ_STARTED (1 << __REQ_STARTED)
121 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
122 #define REQ_QUEUED (1 << __REQ_QUEUED)
123 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
124 #define REQ_FAILED (1 << __REQ_FAILED)
125 #define REQ_QUIET (1 << __REQ_QUIET)
126 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
127 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
128 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
129 #define REQ_ALLOCED (1 << __REQ_ALLOCED)
130 #define REQ_RW_META (1 << __REQ_RW_META)
131 #define REQ_COPY_USER (1 << __REQ_COPY_USER)
132 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
134 #define BLK_MAX_CDB 16
137 * try to put the fields that are referenced together in the same cacheline.
138 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
142 struct list_head queuelist
;
143 struct call_single_data csd
;
146 struct request_queue
*q
;
148 unsigned int cmd_flags
;
149 enum rq_cmd_type_bits cmd_type
;
151 /* Maintain bio traversal state for part by part I/O submission.
152 * hard_* are block layer internals, no driver should touch them!
155 sector_t sector
; /* next sector to submit */
156 sector_t hard_sector
; /* next sector to complete */
157 unsigned long nr_sectors
; /* no. of sectors left to submit */
158 unsigned long hard_nr_sectors
; /* no. of sectors left to complete */
159 /* no. of sectors left to submit in the current segment */
160 unsigned int current_nr_sectors
;
162 /* no. of sectors left to complete in the current segment */
163 unsigned int hard_cur_sectors
;
168 struct hlist_node hash
; /* merge hash */
170 * The rb_node is only used inside the io scheduler, requests
171 * are pruned when moved to the dispatch queue. So let the
172 * completion_data share space with the rb_node.
175 struct rb_node rb_node
; /* sort/lookup */
176 void *completion_data
;
180 * two pointers are available for the IO schedulers, if they need
181 * more they have to dynamically allocate it.
183 void *elevator_private
;
184 void *elevator_private2
;
186 struct gendisk
*rq_disk
;
187 unsigned long start_time
;
189 /* Number of scatter-gather DMA addr+len pairs after
190 * physical address coalescing is performed.
192 unsigned short nr_phys_segments
;
194 unsigned short ioprio
;
205 * when request is used as a packet command carrier
207 unsigned short cmd_len
;
208 unsigned char __cmd
[BLK_MAX_CDB
];
211 unsigned int data_len
;
212 unsigned int extra_len
; /* length of alignment and padding */
213 unsigned int sense_len
;
217 unsigned int timeout
;
221 * completion callback.
223 rq_end_io_fn
*end_io
;
227 struct request
*next_rq
;
230 static inline unsigned short req_get_ioprio(struct request
*req
)
236 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
237 * requests. Some step values could eventually be made generic.
239 struct request_pm_state
241 /* PM state machine step value, currently driver specific */
243 /* requested PM state value (S1, S2, S3, S4, ...) */
245 void* data
; /* for driver use */
248 #include <linux/elevator.h>
250 typedef void (request_fn_proc
) (struct request_queue
*q
);
251 typedef int (make_request_fn
) (struct request_queue
*q
, struct bio
*bio
);
252 typedef int (prep_rq_fn
) (struct request_queue
*, struct request
*);
253 typedef void (unplug_fn
) (struct request_queue
*);
254 typedef int (prepare_discard_fn
) (struct request_queue
*, struct request
*);
257 struct bvec_merge_data
{
258 struct block_device
*bi_bdev
;
263 typedef int (merge_bvec_fn
) (struct request_queue
*, struct bvec_merge_data
*,
265 typedef void (prepare_flush_fn
) (struct request_queue
*, struct request
*);
266 typedef void (softirq_done_fn
)(struct request
*);
267 typedef int (dma_drain_needed_fn
)(struct request
*);
269 enum blk_queue_state
{
274 struct blk_queue_tag
{
275 struct request
**tag_index
; /* map of busy tags */
276 unsigned long *tag_map
; /* bit map of free/busy tags */
277 int busy
; /* current depth */
278 int max_depth
; /* what we will send to device */
279 int real_max_depth
; /* what the array can hold */
280 atomic_t refcnt
; /* map can be shared */
283 #define BLK_SCSI_MAX_CMDS (256)
284 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
286 struct blk_cmd_filter
{
287 unsigned long read_ok
[BLK_SCSI_CMD_PER_LONG
];
288 unsigned long write_ok
[BLK_SCSI_CMD_PER_LONG
];
295 * Together with queue_head for cacheline sharing
297 struct list_head queue_head
;
298 struct request
*last_merge
;
299 elevator_t
*elevator
;
302 * the queue request freelist, one for reads and one for writes
304 struct request_list rq
;
306 request_fn_proc
*request_fn
;
307 make_request_fn
*make_request_fn
;
308 prep_rq_fn
*prep_rq_fn
;
309 unplug_fn
*unplug_fn
;
310 prepare_discard_fn
*prepare_discard_fn
;
311 merge_bvec_fn
*merge_bvec_fn
;
312 prepare_flush_fn
*prepare_flush_fn
;
313 softirq_done_fn
*softirq_done_fn
;
314 dma_drain_needed_fn
*dma_drain_needed
;
317 * Dispatch queue sorting
320 struct request
*boundary_rq
;
323 * Auto-unplugging state
325 struct timer_list unplug_timer
;
326 int unplug_thresh
; /* After this many requests */
327 unsigned long unplug_delay
; /* After this many jiffies */
328 struct work_struct unplug_work
;
330 struct backing_dev_info backing_dev_info
;
333 * The queue owner gets to use this for whatever they like.
334 * ll_rw_blk doesn't touch it.
339 * queue needs bounce pages for pages above this limit
341 unsigned long bounce_pfn
;
345 * various queue flags, see QUEUE_* below
347 unsigned long queue_flags
;
350 * protects queue structures from reentrancy. ->__queue_lock should
351 * _never_ be used directly, it is queue private. always use
354 spinlock_t __queue_lock
;
355 spinlock_t
*queue_lock
;
365 unsigned long nr_requests
; /* Max # of requests */
366 unsigned int nr_congestion_on
;
367 unsigned int nr_congestion_off
;
368 unsigned int nr_batching
;
370 unsigned int max_sectors
;
371 unsigned int max_hw_sectors
;
372 unsigned short max_phys_segments
;
373 unsigned short max_hw_segments
;
374 unsigned short hardsect_size
;
375 unsigned int max_segment_size
;
377 unsigned long seg_boundary_mask
;
378 void *dma_drain_buffer
;
379 unsigned int dma_drain_size
;
380 unsigned int dma_pad_mask
;
381 unsigned int dma_alignment
;
383 struct blk_queue_tag
*queue_tags
;
384 struct list_head tag_busy_list
;
386 unsigned int nr_sorted
;
387 unsigned int in_flight
;
392 unsigned int sg_timeout
;
393 unsigned int sg_reserved_size
;
395 #ifdef CONFIG_BLK_DEV_IO_TRACE
396 struct blk_trace
*blk_trace
;
399 * reserved for flush operations
401 unsigned int ordered
, next_ordered
, ordseq
;
402 int orderr
, ordcolor
;
403 struct request pre_flush_rq
, bar_rq
, post_flush_rq
;
404 struct request
*orig_bar_rq
;
406 struct mutex sysfs_lock
;
408 #if defined(CONFIG_BLK_DEV_BSG)
409 struct bsg_class_device bsg_dev
;
411 struct blk_cmd_filter cmd_filter
;
414 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
415 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
416 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
417 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
418 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
419 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
420 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
421 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
422 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
423 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
424 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
425 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
427 static inline int queue_is_locked(struct request_queue
*q
)
430 spinlock_t
*lock
= q
->queue_lock
;
431 return lock
&& spin_is_locked(lock
);
437 static inline void queue_flag_set_unlocked(unsigned int flag
,
438 struct request_queue
*q
)
440 __set_bit(flag
, &q
->queue_flags
);
443 static inline int queue_flag_test_and_clear(unsigned int flag
,
444 struct request_queue
*q
)
446 WARN_ON_ONCE(!queue_is_locked(q
));
448 if (test_bit(flag
, &q
->queue_flags
)) {
449 __clear_bit(flag
, &q
->queue_flags
);
456 static inline int queue_flag_test_and_set(unsigned int flag
,
457 struct request_queue
*q
)
459 WARN_ON_ONCE(!queue_is_locked(q
));
461 if (!test_bit(flag
, &q
->queue_flags
)) {
462 __set_bit(flag
, &q
->queue_flags
);
469 static inline void queue_flag_set(unsigned int flag
, struct request_queue
*q
)
471 WARN_ON_ONCE(!queue_is_locked(q
));
472 __set_bit(flag
, &q
->queue_flags
);
475 static inline void queue_flag_clear_unlocked(unsigned int flag
,
476 struct request_queue
*q
)
478 __clear_bit(flag
, &q
->queue_flags
);
481 static inline void queue_flag_clear(unsigned int flag
, struct request_queue
*q
)
483 WARN_ON_ONCE(!queue_is_locked(q
));
484 __clear_bit(flag
, &q
->queue_flags
);
489 * Hardbarrier is supported with one of the following methods.
491 * NONE : hardbarrier unsupported
492 * DRAIN : ordering by draining is enough
493 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
494 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
495 * TAG : ordering by tag is enough
496 * TAG_FLUSH : ordering by tag w/ pre and post flushes
497 * TAG_FUA : ordering by tag w/ pre flush and FUA write
499 QUEUE_ORDERED_NONE
= 0x00,
500 QUEUE_ORDERED_DRAIN
= 0x01,
501 QUEUE_ORDERED_TAG
= 0x02,
503 QUEUE_ORDERED_PREFLUSH
= 0x10,
504 QUEUE_ORDERED_POSTFLUSH
= 0x20,
505 QUEUE_ORDERED_FUA
= 0x40,
507 QUEUE_ORDERED_DRAIN_FLUSH
= QUEUE_ORDERED_DRAIN
|
508 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
509 QUEUE_ORDERED_DRAIN_FUA
= QUEUE_ORDERED_DRAIN
|
510 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
511 QUEUE_ORDERED_TAG_FLUSH
= QUEUE_ORDERED_TAG
|
512 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_POSTFLUSH
,
513 QUEUE_ORDERED_TAG_FUA
= QUEUE_ORDERED_TAG
|
514 QUEUE_ORDERED_PREFLUSH
| QUEUE_ORDERED_FUA
,
517 * Ordered operation sequence
519 QUEUE_ORDSEQ_STARTED
= 0x01, /* flushing in progress */
520 QUEUE_ORDSEQ_DRAIN
= 0x02, /* waiting for the queue to be drained */
521 QUEUE_ORDSEQ_PREFLUSH
= 0x04, /* pre-flushing in progress */
522 QUEUE_ORDSEQ_BAR
= 0x08, /* original barrier req in progress */
523 QUEUE_ORDSEQ_POSTFLUSH
= 0x10, /* post-flushing in progress */
524 QUEUE_ORDSEQ_DONE
= 0x20,
527 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
528 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
529 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
530 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
531 #define blk_queue_flushing(q) ((q)->ordseq)
533 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
534 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
535 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
536 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
538 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
539 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
541 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
543 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
544 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
545 #define blk_pm_request(rq) \
546 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
548 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
549 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
550 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
551 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
552 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
553 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
554 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
555 /* rq->queuelist of dequeued request must be list_empty() */
556 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
558 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
560 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
563 * We regard a request as sync, if it's a READ or a SYNC write.
565 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
566 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
568 static inline int blk_queue_full(struct request_queue
*q
, int rw
)
571 return test_bit(QUEUE_FLAG_READFULL
, &q
->queue_flags
);
572 return test_bit(QUEUE_FLAG_WRITEFULL
, &q
->queue_flags
);
575 static inline void blk_set_queue_full(struct request_queue
*q
, int rw
)
578 queue_flag_set(QUEUE_FLAG_READFULL
, q
);
580 queue_flag_set(QUEUE_FLAG_WRITEFULL
, q
);
583 static inline void blk_clear_queue_full(struct request_queue
*q
, int rw
)
586 queue_flag_clear(QUEUE_FLAG_READFULL
, q
);
588 queue_flag_clear(QUEUE_FLAG_WRITEFULL
, q
);
593 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
594 * it already be started by driver.
596 #define RQ_NOMERGE_FLAGS \
597 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
598 #define rq_mergeable(rq) \
599 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
600 (blk_discard_rq(rq) || blk_fs_request((rq))))
603 * q->prep_rq_fn return values
605 #define BLKPREP_OK 0 /* serve it */
606 #define BLKPREP_KILL 1 /* fatal error, kill */
607 #define BLKPREP_DEFER 2 /* leave on queue */
609 extern unsigned long blk_max_low_pfn
, blk_max_pfn
;
612 * standard bounce addresses:
614 * BLK_BOUNCE_HIGH : bounce all highmem pages
615 * BLK_BOUNCE_ANY : don't bounce anything
616 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
619 #if BITS_PER_LONG == 32
620 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
622 #define BLK_BOUNCE_HIGH -1ULL
624 #define BLK_BOUNCE_ANY (-1ULL)
625 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
628 * default timeout for SG_IO if none specified
630 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
633 extern int init_emergency_isa_pool(void);
634 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
636 static inline int init_emergency_isa_pool(void)
640 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
643 #endif /* CONFIG_MMU */
651 struct req_iterator
{
656 /* This should not be used directly - use rq_for_each_segment */
657 #define __rq_for_each_bio(_bio, rq) \
659 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
661 #define rq_for_each_segment(bvl, _rq, _iter) \
662 __rq_for_each_bio(_iter.bio, _rq) \
663 bio_for_each_segment(bvl, _iter.bio, _iter.i)
665 #define rq_iter_last(rq, _iter) \
666 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
668 extern int blk_register_queue(struct gendisk
*disk
);
669 extern void blk_unregister_queue(struct gendisk
*disk
);
670 extern void register_disk(struct gendisk
*dev
);
671 extern void generic_make_request(struct bio
*bio
);
672 extern void blk_rq_init(struct request_queue
*q
, struct request
*rq
);
673 extern void blk_put_request(struct request
*);
674 extern void __blk_put_request(struct request_queue
*, struct request
*);
675 extern struct request
*blk_get_request(struct request_queue
*, int, gfp_t
);
676 extern void blk_insert_request(struct request_queue
*, struct request
*, int, void *);
677 extern void blk_requeue_request(struct request_queue
*, struct request
*);
678 extern void blk_plug_device(struct request_queue
*);
679 extern void blk_plug_device_unlocked(struct request_queue
*);
680 extern int blk_remove_plug(struct request_queue
*);
681 extern void blk_recount_segments(struct request_queue
*, struct bio
*);
682 extern int scsi_cmd_ioctl(struct file
*, struct request_queue
*,
683 struct gendisk
*, unsigned int, void __user
*);
684 extern int sg_scsi_ioctl(struct file
*, struct request_queue
*,
685 struct gendisk
*, struct scsi_ioctl_command __user
*);
688 * Temporary export, until SCSI gets fixed up.
690 extern int blk_rq_append_bio(struct request_queue
*q
, struct request
*rq
,
694 * A queue has just exitted congestion. Note this in the global counter of
695 * congested queues, and wake up anyone who was waiting for requests to be
698 static inline void blk_clear_queue_congested(struct request_queue
*q
, int rw
)
700 clear_bdi_congested(&q
->backing_dev_info
, rw
);
704 * A queue has just entered congestion. Flag that in the queue's VM-visible
705 * state flags and increment the global gounter of congested queues.
707 static inline void blk_set_queue_congested(struct request_queue
*q
, int rw
)
709 set_bdi_congested(&q
->backing_dev_info
, rw
);
712 extern void blk_start_queue(struct request_queue
*q
);
713 extern void blk_stop_queue(struct request_queue
*q
);
714 extern void blk_sync_queue(struct request_queue
*q
);
715 extern void __blk_stop_queue(struct request_queue
*q
);
716 extern void __blk_run_queue(struct request_queue
*);
717 extern void blk_run_queue(struct request_queue
*);
718 extern void blk_start_queueing(struct request_queue
*);
719 extern int blk_rq_map_user(struct request_queue
*, struct request
*,
720 struct rq_map_data
*, void __user
*, unsigned long,
722 extern int blk_rq_unmap_user(struct bio
*);
723 extern int blk_rq_map_kern(struct request_queue
*, struct request
*, void *, unsigned int, gfp_t
);
724 extern int blk_rq_map_user_iov(struct request_queue
*, struct request
*,
725 struct rq_map_data
*, struct sg_iovec
*, int,
726 unsigned int, gfp_t
);
727 extern int blk_execute_rq(struct request_queue
*, struct gendisk
*,
728 struct request
*, int);
729 extern void blk_execute_rq_nowait(struct request_queue
*, struct gendisk
*,
730 struct request
*, int, rq_end_io_fn
*);
731 extern void blk_unplug(struct request_queue
*q
);
733 static inline struct request_queue
*bdev_get_queue(struct block_device
*bdev
)
735 return bdev
->bd_disk
->queue
;
738 static inline void blk_run_backing_dev(struct backing_dev_info
*bdi
,
741 if (bdi
&& bdi
->unplug_io_fn
)
742 bdi
->unplug_io_fn(bdi
, page
);
745 static inline void blk_run_address_space(struct address_space
*mapping
)
748 blk_run_backing_dev(mapping
->backing_dev_info
, NULL
);
752 * blk_end_request() and friends.
753 * __blk_end_request() and end_request() must be called with
754 * the request queue spinlock acquired.
756 * Several drivers define their own end_request and call
757 * blk_end_request() for parts of the original function.
758 * This prevents code duplication in drivers.
760 extern int blk_end_request(struct request
*rq
, int error
,
761 unsigned int nr_bytes
);
762 extern int __blk_end_request(struct request
*rq
, int error
,
763 unsigned int nr_bytes
);
764 extern int blk_end_bidi_request(struct request
*rq
, int error
,
765 unsigned int nr_bytes
, unsigned int bidi_bytes
);
766 extern void end_request(struct request
*, int);
767 extern void end_queued_request(struct request
*, int);
768 extern void end_dequeued_request(struct request
*, int);
769 extern int blk_end_request_callback(struct request
*rq
, int error
,
770 unsigned int nr_bytes
,
771 int (drv_callback
)(struct request
*));
772 extern void blk_complete_request(struct request
*);
775 * blk_end_request() takes bytes instead of sectors as a complete size.
776 * blk_rq_bytes() returns bytes left to complete in the entire request.
777 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
779 extern unsigned int blk_rq_bytes(struct request
*rq
);
780 extern unsigned int blk_rq_cur_bytes(struct request
*rq
);
782 static inline void blkdev_dequeue_request(struct request
*req
)
784 elv_dequeue_request(req
->q
, req
);
788 * Access functions for manipulating queue properties
790 extern struct request_queue
*blk_init_queue_node(request_fn_proc
*rfn
,
791 spinlock_t
*lock
, int node_id
);
792 extern struct request_queue
*blk_init_queue(request_fn_proc
*, spinlock_t
*);
793 extern void blk_cleanup_queue(struct request_queue
*);
794 extern void blk_queue_make_request(struct request_queue
*, make_request_fn
*);
795 extern void blk_queue_bounce_limit(struct request_queue
*, u64
);
796 extern void blk_queue_max_sectors(struct request_queue
*, unsigned int);
797 extern void blk_queue_max_phys_segments(struct request_queue
*, unsigned short);
798 extern void blk_queue_max_hw_segments(struct request_queue
*, unsigned short);
799 extern void blk_queue_max_segment_size(struct request_queue
*, unsigned int);
800 extern void blk_queue_hardsect_size(struct request_queue
*, unsigned short);
801 extern void blk_queue_stack_limits(struct request_queue
*t
, struct request_queue
*b
);
802 extern void blk_queue_dma_pad(struct request_queue
*, unsigned int);
803 extern void blk_queue_update_dma_pad(struct request_queue
*, unsigned int);
804 extern int blk_queue_dma_drain(struct request_queue
*q
,
805 dma_drain_needed_fn
*dma_drain_needed
,
806 void *buf
, unsigned int size
);
807 extern void blk_queue_segment_boundary(struct request_queue
*, unsigned long);
808 extern void blk_queue_prep_rq(struct request_queue
*, prep_rq_fn
*pfn
);
809 extern void blk_queue_merge_bvec(struct request_queue
*, merge_bvec_fn
*);
810 extern void blk_queue_dma_alignment(struct request_queue
*, int);
811 extern void blk_queue_update_dma_alignment(struct request_queue
*, int);
812 extern void blk_queue_softirq_done(struct request_queue
*, softirq_done_fn
*);
813 extern void blk_queue_set_discard(struct request_queue
*, prepare_discard_fn
*);
814 extern struct backing_dev_info
*blk_get_backing_dev_info(struct block_device
*bdev
);
815 extern int blk_queue_ordered(struct request_queue
*, unsigned, prepare_flush_fn
*);
816 extern int blk_do_ordered(struct request_queue
*, struct request
**);
817 extern unsigned blk_ordered_cur_seq(struct request_queue
*);
818 extern unsigned blk_ordered_req_seq(struct request
*);
819 extern void blk_ordered_complete_seq(struct request_queue
*, unsigned, int);
821 extern int blk_rq_map_sg(struct request_queue
*, struct request
*, struct scatterlist
*);
822 extern void blk_dump_rq_flags(struct request
*, char *);
823 extern void generic_unplug_device(struct request_queue
*);
824 extern void __generic_unplug_device(struct request_queue
*);
825 extern long nr_blockdev_pages(void);
827 int blk_get_queue(struct request_queue
*);
828 struct request_queue
*blk_alloc_queue(gfp_t
);
829 struct request_queue
*blk_alloc_queue_node(gfp_t
, int);
830 extern void blk_put_queue(struct request_queue
*);
835 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
836 extern int blk_queue_start_tag(struct request_queue
*, struct request
*);
837 extern struct request
*blk_queue_find_tag(struct request_queue
*, int);
838 extern void blk_queue_end_tag(struct request_queue
*, struct request
*);
839 extern int blk_queue_init_tags(struct request_queue
*, int, struct blk_queue_tag
*);
840 extern void blk_queue_free_tags(struct request_queue
*);
841 extern int blk_queue_resize_tags(struct request_queue
*, int);
842 extern void blk_queue_invalidate_tags(struct request_queue
*);
843 extern struct blk_queue_tag
*blk_init_tags(int);
844 extern void blk_free_tags(struct blk_queue_tag
*);
846 static inline struct request
*blk_map_queue_find_tag(struct blk_queue_tag
*bqt
,
849 if (unlikely(bqt
== NULL
|| tag
>= bqt
->real_max_depth
))
851 return bqt
->tag_index
[tag
];
854 extern int blkdev_issue_flush(struct block_device
*, sector_t
*);
855 extern int blkdev_issue_discard(struct block_device
*, sector_t sector
,
858 static inline int sb_issue_discard(struct super_block
*sb
,
859 sector_t block
, unsigned nr_blocks
)
861 block
<<= (sb
->s_blocksize_bits
- 9);
862 nr_blocks
<<= (sb
->s_blocksize_bits
- 9);
863 return blkdev_issue_discard(sb
->s_bdev
, block
, nr_blocks
);
867 * command filter functions
869 extern int blk_verify_command(struct blk_cmd_filter
*filter
,
870 unsigned char *cmd
, int has_write_perm
);
871 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter
*filter
);
873 #define MAX_PHYS_SEGMENTS 128
874 #define MAX_HW_SEGMENTS 128
875 #define SAFE_MAX_SECTORS 255
876 #define BLK_DEF_MAX_SECTORS 1024
878 #define MAX_SEGMENT_SIZE 65536
880 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
882 static inline int queue_hardsect_size(struct request_queue
*q
)
886 if (q
&& q
->hardsect_size
)
887 retval
= q
->hardsect_size
;
892 static inline int bdev_hardsect_size(struct block_device
*bdev
)
894 return queue_hardsect_size(bdev_get_queue(bdev
));
897 static inline int queue_dma_alignment(struct request_queue
*q
)
899 return q
? q
->dma_alignment
: 511;
902 static inline int blk_rq_aligned(struct request_queue
*q
, void *addr
,
905 unsigned int alignment
= queue_dma_alignment(q
) | q
->dma_pad_mask
;
906 return !((unsigned long)addr
& alignment
) && !(len
& alignment
);
909 /* assumes size > 256 */
910 static inline unsigned int blksize_bits(unsigned int size
)
912 unsigned int bits
= 8;
916 } while (size
> 256);
920 static inline unsigned int block_size(struct block_device
*bdev
)
922 return bdev
->bd_block_size
;
925 typedef struct {struct page
*v
;} Sector
;
927 unsigned char *read_dev_sector(struct block_device
*, sector_t
, Sector
*);
929 static inline void put_dev_sector(Sector p
)
931 page_cache_release(p
.v
);
935 int kblockd_schedule_work(struct request_queue
*q
, struct work_struct
*work
);
936 void kblockd_flush_work(struct work_struct
*work
);
938 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
939 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
940 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
941 MODULE_ALIAS("block-major-" __stringify(major) "-*")
943 #if defined(CONFIG_BLK_DEV_INTEGRITY)
945 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
946 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
948 struct blk_integrity_exchg
{
952 unsigned int data_size
;
953 unsigned short sector_size
;
954 const char *disk_name
;
957 typedef void (integrity_gen_fn
) (struct blk_integrity_exchg
*);
958 typedef int (integrity_vrfy_fn
) (struct blk_integrity_exchg
*);
959 typedef void (integrity_set_tag_fn
) (void *, void *, unsigned int);
960 typedef void (integrity_get_tag_fn
) (void *, void *, unsigned int);
962 struct blk_integrity
{
963 integrity_gen_fn
*generate_fn
;
964 integrity_vrfy_fn
*verify_fn
;
965 integrity_set_tag_fn
*set_tag_fn
;
966 integrity_get_tag_fn
*get_tag_fn
;
968 unsigned short flags
;
969 unsigned short tuple_size
;
970 unsigned short sector_size
;
971 unsigned short tag_size
;
978 extern int blk_integrity_register(struct gendisk
*, struct blk_integrity
*);
979 extern void blk_integrity_unregister(struct gendisk
*);
980 extern int blk_integrity_compare(struct block_device
*, struct block_device
*);
981 extern int blk_rq_map_integrity_sg(struct request
*, struct scatterlist
*);
982 extern int blk_rq_count_integrity_sg(struct request
*);
984 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity
*bi
)
987 return bi
->tuple_size
;
992 static inline struct blk_integrity
*bdev_get_integrity(struct block_device
*bdev
)
994 return bdev
->bd_disk
->integrity
;
997 static inline unsigned int bdev_get_tag_size(struct block_device
*bdev
)
999 struct blk_integrity
*bi
= bdev_get_integrity(bdev
);
1002 return bi
->tag_size
;
1007 static inline int bdev_integrity_enabled(struct block_device
*bdev
, int rw
)
1009 struct blk_integrity
*bi
= bdev_get_integrity(bdev
);
1014 if (rw
== READ
&& bi
->verify_fn
!= NULL
&&
1015 (bi
->flags
& INTEGRITY_FLAG_READ
))
1018 if (rw
== WRITE
&& bi
->generate_fn
!= NULL
&&
1019 (bi
->flags
& INTEGRITY_FLAG_WRITE
))
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 bdev_get_tag_size(a) (0)
1040 #define blk_integrity_compare(a, b) (0)
1041 #define blk_integrity_register(a, b) (0)
1042 #define blk_integrity_unregister(a) do { } while (0);
1044 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1046 #else /* CONFIG_BLOCK */
1048 * stubs for when the block layer is configured out
1050 #define buffer_heads_over_limit 0
1052 static inline long nr_blockdev_pages(void)
1057 #endif /* CONFIG_BLOCK */