1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
6 #include <linux/sched.h>
7 #include <linux/major.h>
8 #include <linux/genhd.h>
9 #include <linux/list.h>
10 #include <linux/timer.h>
11 #include <linux/workqueue.h>
12 #include <linux/pagemap.h>
13 #include <linux/backing-dev.h>
14 #include <linux/wait.h>
15 #include <linux/mempool.h>
16 #include <linux/bio.h>
17 #include <linux/module.h>
18 #include <linux/stringify.h>
19 #include <linux/bsg.h>
21 #include <asm/scatterlist.h>
23 struct scsi_ioctl_command;
26 struct elevator_queue;
27 typedef struct elevator_queue elevator_t;
28 struct request_pm_state;
33 #define BLKDEV_MIN_RQ 4
34 #define BLKDEV_MAX_RQ 128 /* Default maximum */
37 typedef void (rq_end_io_fn)(struct request *, int);
44 wait_queue_head_t wait[2];
48 * request command types
50 enum rq_cmd_type_bits {
51 REQ_TYPE_FS = 1, /* fs request */
52 REQ_TYPE_BLOCK_PC, /* scsi command */
53 REQ_TYPE_SENSE, /* sense request */
54 REQ_TYPE_PM_SUSPEND, /* suspend request */
55 REQ_TYPE_PM_RESUME, /* resume request */
56 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
57 REQ_TYPE_FLUSH, /* flush 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.
80 * just examples for now
82 REQ_LB_OP_EJECT = 0x40, /* eject request */
83 REQ_LB_OP_FLUSH = 0x41, /* flush device */
84 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
88 * request type modified bits. first two bits match BIO_RW* bits, important
91 __REQ_RW, /* not set, read. set, write */
92 __REQ_FAILFAST, /* no low level driver retries */
93 __REQ_DISCARD, /* request to discard sectors */
94 __REQ_SORTED, /* elevator knows about this request */
95 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
96 __REQ_HARDBARRIER, /* may not be passed by drive either */
97 __REQ_FUA, /* forced unit access */
98 __REQ_NOMERGE, /* don't touch this for merging */
99 __REQ_STARTED, /* drive already may have started this one */
100 __REQ_DONTPREP, /* don't call prep for this one */
101 __REQ_QUEUED, /* uses queueing */
102 __REQ_ELVPRIV, /* elevator private data attached */
103 __REQ_FAILED, /* set if the request failed */
104 __REQ_QUIET, /* don't worry about errors */
105 __REQ_PREEMPT, /* set for "ide_preempt" requests */
106 __REQ_ORDERED_COLOR, /* is before or after barrier */
107 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
108 __REQ_ALLOCED, /* request came from our alloc pool */
109 __REQ_RW_META, /* metadata io request */
110 __REQ_COPY_USER, /* contains copies of user pages */
111 __REQ_INTEGRITY, /* integrity metadata has been remapped */
112 __REQ_NR_BITS, /* stops here */
115 #define REQ_RW (1 << __REQ_RW)
116 #define REQ_DISCARD (1 << __REQ_DISCARD)
117 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
118 #define REQ_SORTED (1 << __REQ_SORTED)
119 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
120 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
121 #define REQ_FUA (1 << __REQ_FUA)
122 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
123 #define REQ_STARTED (1 << __REQ_STARTED)
124 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
125 #define REQ_QUEUED (1 << __REQ_QUEUED)
126 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
127 #define REQ_FAILED (1 << __REQ_FAILED)
128 #define REQ_QUIET (1 << __REQ_QUIET)
129 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
130 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
131 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
132 #define REQ_ALLOCED (1 << __REQ_ALLOCED)
133 #define REQ_RW_META (1 << __REQ_RW_META)
134 #define REQ_COPY_USER (1 << __REQ_COPY_USER)
135 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
137 #define BLK_MAX_CDB 16
140 * try to put the fields that are referenced together in the same cacheline.
141 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
145 struct list_head queuelist;
146 struct list_head donelist;
148 struct request_queue *q;
150 unsigned int cmd_flags;
151 enum rq_cmd_type_bits cmd_type;
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 /* Number of scatter-gather addr+len pairs after
197 * physical and DMA remapping hardware coalescing is performed.
198 * This is the number of scatter-gather entries the driver
199 * will actually have to deal with after DMA mapping is done.
201 unsigned short nr_hw_segments;
203 unsigned short ioprio;
214 * when request is used as a packet command carrier
216 unsigned short cmd_len;
217 unsigned char __cmd[BLK_MAX_CDB];
220 unsigned int data_len;
221 unsigned int extra_len; /* length of alignment and padding */
222 unsigned int sense_len;
226 unsigned int timeout;
230 * completion callback.
232 rq_end_io_fn *end_io;
236 struct request *next_rq;
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_queue_state {
278 struct blk_queue_tag {
279 struct request **tag_index; /* map of busy tags */
280 unsigned long *tag_map; /* bit map of free/busy tags */
281 int busy; /* current depth */
282 int max_depth; /* what we will send to device */
283 int real_max_depth; /* what the array can hold */
284 atomic_t refcnt; /* map can be shared */
287 #define BLK_SCSI_MAX_CMDS (256)
288 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
290 struct blk_cmd_filter {
291 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
292 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
299 * Together with queue_head for cacheline sharing
301 struct list_head queue_head;
302 struct request *last_merge;
303 elevator_t *elevator;
306 * the queue request freelist, one for reads and one for writes
308 struct request_list rq;
310 request_fn_proc *request_fn;
311 make_request_fn *make_request_fn;
312 prep_rq_fn *prep_rq_fn;
313 unplug_fn *unplug_fn;
314 prepare_discard_fn *prepare_discard_fn;
315 merge_bvec_fn *merge_bvec_fn;
316 prepare_flush_fn *prepare_flush_fn;
317 softirq_done_fn *softirq_done_fn;
318 dma_drain_needed_fn *dma_drain_needed;
321 * Dispatch queue sorting
324 struct request *boundary_rq;
327 * Auto-unplugging state
329 struct timer_list unplug_timer;
330 int unplug_thresh; /* After this many requests */
331 unsigned long unplug_delay; /* After this many jiffies */
332 struct work_struct unplug_work;
334 struct backing_dev_info backing_dev_info;
337 * The queue owner gets to use this for whatever they like.
338 * ll_rw_blk doesn't touch it.
343 * queue needs bounce pages for pages above this limit
345 unsigned long bounce_pfn;
349 * various queue flags, see QUEUE_* below
351 unsigned long queue_flags;
354 * protects queue structures from reentrancy. ->__queue_lock should
355 * _never_ be used directly, it is queue private. always use
358 spinlock_t __queue_lock;
359 spinlock_t *queue_lock;
369 unsigned long nr_requests; /* Max # of requests */
370 unsigned int nr_congestion_on;
371 unsigned int nr_congestion_off;
372 unsigned int nr_batching;
374 unsigned int max_sectors;
375 unsigned int max_hw_sectors;
376 unsigned short max_phys_segments;
377 unsigned short max_hw_segments;
378 unsigned short hardsect_size;
379 unsigned int max_segment_size;
381 unsigned long seg_boundary_mask;
382 void *dma_drain_buffer;
383 unsigned int dma_drain_size;
384 unsigned int dma_pad_mask;
385 unsigned int dma_alignment;
387 struct blk_queue_tag *queue_tags;
388 struct list_head tag_busy_list;
390 unsigned int nr_sorted;
391 unsigned int in_flight;
396 unsigned int sg_timeout;
397 unsigned int sg_reserved_size;
399 #ifdef CONFIG_BLK_DEV_IO_TRACE
400 struct blk_trace *blk_trace;
403 * reserved for flush operations
405 unsigned int ordered, next_ordered, ordseq;
406 int orderr, ordcolor;
407 struct request pre_flush_rq, bar_rq, post_flush_rq;
408 struct request *orig_bar_rq;
410 struct mutex sysfs_lock;
412 #if defined(CONFIG_BLK_DEV_BSG)
413 struct bsg_class_device bsg_dev;
415 struct blk_cmd_filter cmd_filter;
418 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
419 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
420 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
421 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
422 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
423 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
424 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
425 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
426 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
427 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
428 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
430 static inline int queue_is_locked(struct request_queue *q)
433 spinlock_t *lock = q->queue_lock;
434 return lock && spin_is_locked(lock);
440 static inline void queue_flag_set_unlocked(unsigned int flag,
441 struct request_queue *q)
443 __set_bit(flag, &q->queue_flags);
446 static inline int queue_flag_test_and_clear(unsigned int flag,
447 struct request_queue *q)
449 WARN_ON_ONCE(!queue_is_locked(q));
451 if (test_bit(flag, &q->queue_flags)) {
452 __clear_bit(flag, &q->queue_flags);
459 static inline int queue_flag_test_and_set(unsigned int flag,
460 struct request_queue *q)
462 WARN_ON_ONCE(!queue_is_locked(q));
464 if (!test_bit(flag, &q->queue_flags)) {
465 __set_bit(flag, &q->queue_flags);
472 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
474 WARN_ON_ONCE(!queue_is_locked(q));
475 __set_bit(flag, &q->queue_flags);
478 static inline void queue_flag_clear_unlocked(unsigned int flag,
479 struct request_queue *q)
481 __clear_bit(flag, &q->queue_flags);
484 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
486 WARN_ON_ONCE(!queue_is_locked(q));
487 __clear_bit(flag, &q->queue_flags);
492 * Hardbarrier is supported with one of the following methods.
494 * NONE : hardbarrier unsupported
495 * DRAIN : ordering by draining is enough
496 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
497 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
498 * TAG : ordering by tag is enough
499 * TAG_FLUSH : ordering by tag w/ pre and post flushes
500 * TAG_FUA : ordering by tag w/ pre flush and FUA write
502 QUEUE_ORDERED_NONE = 0x00,
503 QUEUE_ORDERED_DRAIN = 0x01,
504 QUEUE_ORDERED_TAG = 0x02,
506 QUEUE_ORDERED_PREFLUSH = 0x10,
507 QUEUE_ORDERED_POSTFLUSH = 0x20,
508 QUEUE_ORDERED_FUA = 0x40,
510 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
511 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
512 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
513 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
514 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
515 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
516 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
517 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
520 * Ordered operation sequence
522 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
523 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
524 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
525 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
526 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
527 QUEUE_ORDSEQ_DONE = 0x20,
530 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
531 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
532 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
533 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
534 #define blk_queue_flushing(q) ((q)->ordseq)
536 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
537 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
538 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
539 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
541 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
542 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
544 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
546 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
547 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
548 #define blk_pm_request(rq) \
549 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
551 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
552 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
553 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
554 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
555 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
556 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
557 /* rq->queuelist of dequeued request must be list_empty() */
558 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
560 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
562 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
565 * We regard a request as sync, if it's a READ or a SYNC write.
567 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
568 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
570 static inline int blk_queue_full(struct request_queue *q, int rw)
573 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
574 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
577 static inline void blk_set_queue_full(struct request_queue *q, int rw)
580 queue_flag_set(QUEUE_FLAG_READFULL, q);
582 queue_flag_set(QUEUE_FLAG_WRITEFULL, q);
585 static inline void blk_clear_queue_full(struct request_queue *q, int rw)
588 queue_flag_clear(QUEUE_FLAG_READFULL, q);
590 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q);
595 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
596 * it already be started by driver.
598 #define RQ_NOMERGE_FLAGS \
599 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
600 #define rq_mergeable(rq) \
601 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
602 (blk_discard_rq(rq) || blk_fs_request((rq))))
605 * q->prep_rq_fn return values
607 #define BLKPREP_OK 0 /* serve it */
608 #define BLKPREP_KILL 1 /* fatal error, kill */
609 #define BLKPREP_DEFER 2 /* leave on queue */
611 extern unsigned long blk_max_low_pfn, blk_max_pfn;
614 * standard bounce addresses:
616 * BLK_BOUNCE_HIGH : bounce all highmem pages
617 * BLK_BOUNCE_ANY : don't bounce anything
618 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
621 #if BITS_PER_LONG == 32
622 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
624 #define BLK_BOUNCE_HIGH -1ULL
626 #define BLK_BOUNCE_ANY (-1ULL)
627 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
630 * default timeout for SG_IO if none specified
632 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
635 extern int init_emergency_isa_pool(void);
636 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
638 static inline int init_emergency_isa_pool(void)
642 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
645 #endif /* CONFIG_MMU */
647 struct req_iterator {
652 /* This should not be used directly - use rq_for_each_segment */
653 #define __rq_for_each_bio(_bio, rq) \
655 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
657 #define rq_for_each_segment(bvl, _rq, _iter) \
658 __rq_for_each_bio(_iter.bio, _rq) \
659 bio_for_each_segment(bvl, _iter.bio, _iter.i)
661 #define rq_iter_last(rq, _iter) \
662 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
664 extern int blk_register_queue(struct gendisk *disk);
665 extern void blk_unregister_queue(struct gendisk *disk);
666 extern void register_disk(struct gendisk *dev);
667 extern void generic_make_request(struct bio *bio);
668 extern void blk_rq_init(struct request_queue *q, struct request *rq);
669 extern void blk_put_request(struct request *);
670 extern void __blk_put_request(struct request_queue *, struct request *);
671 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
672 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
673 extern void blk_requeue_request(struct request_queue *, struct request *);
674 extern void blk_plug_device(struct request_queue *);
675 extern void blk_plug_device_unlocked(struct request_queue *);
676 extern int blk_remove_plug(struct request_queue *);
677 extern void blk_recount_segments(struct request_queue *, struct bio *);
678 extern int scsi_cmd_ioctl(struct file *, struct request_queue *,
679 struct gendisk *, unsigned int, void __user *);
680 extern int sg_scsi_ioctl(struct file *, struct request_queue *,
681 struct gendisk *, struct scsi_ioctl_command __user *);
684 * Temporary export, until SCSI gets fixed up.
686 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
690 * A queue has just exitted congestion. Note this in the global counter of
691 * congested queues, and wake up anyone who was waiting for requests to be
694 static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
696 clear_bdi_congested(&q->backing_dev_info, rw);
700 * A queue has just entered congestion. Flag that in the queue's VM-visible
701 * state flags and increment the global gounter of congested queues.
703 static inline void blk_set_queue_congested(struct request_queue *q, int rw)
705 set_bdi_congested(&q->backing_dev_info, rw);
708 extern void blk_start_queue(struct request_queue *q);
709 extern void blk_stop_queue(struct request_queue *q);
710 extern void blk_sync_queue(struct request_queue *q);
711 extern void __blk_stop_queue(struct request_queue *q);
712 extern void __blk_run_queue(struct request_queue *);
713 extern void blk_run_queue(struct request_queue *);
714 extern void blk_start_queueing(struct request_queue *);
715 extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long);
716 extern int blk_rq_unmap_user(struct bio *);
717 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
718 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
719 struct sg_iovec *, int, unsigned int);
720 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
721 struct request *, int);
722 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
723 struct request *, int, rq_end_io_fn *);
724 extern void blk_unplug(struct request_queue *q);
726 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
728 return bdev->bd_disk->queue;
731 static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
734 if (bdi && bdi->unplug_io_fn)
735 bdi->unplug_io_fn(bdi, page);
738 static inline void blk_run_address_space(struct address_space *mapping)
741 blk_run_backing_dev(mapping->backing_dev_info, NULL);
745 * blk_end_request() and friends.
746 * __blk_end_request() and end_request() must be called with
747 * the request queue spinlock acquired.
749 * Several drivers define their own end_request and call
750 * blk_end_request() for parts of the original function.
751 * This prevents code duplication in drivers.
753 extern int blk_end_request(struct request *rq, int error,
754 unsigned int nr_bytes);
755 extern int __blk_end_request(struct request *rq, int error,
756 unsigned int nr_bytes);
757 extern int blk_end_bidi_request(struct request *rq, int error,
758 unsigned int nr_bytes, unsigned int bidi_bytes);
759 extern void end_request(struct request *, int);
760 extern void end_queued_request(struct request *, int);
761 extern void end_dequeued_request(struct request *, int);
762 extern int blk_end_request_callback(struct request *rq, int error,
763 unsigned int nr_bytes,
764 int (drv_callback)(struct request *));
765 extern void blk_complete_request(struct request *);
768 * blk_end_request() takes bytes instead of sectors as a complete size.
769 * blk_rq_bytes() returns bytes left to complete in the entire request.
770 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
772 extern unsigned int blk_rq_bytes(struct request *rq);
773 extern unsigned int blk_rq_cur_bytes(struct request *rq);
775 static inline void blkdev_dequeue_request(struct request *req)
777 elv_dequeue_request(req->q, req);
781 * Access functions for manipulating queue properties
783 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
784 spinlock_t *lock, int node_id);
785 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
786 extern void blk_cleanup_queue(struct request_queue *);
787 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
788 extern void blk_queue_bounce_limit(struct request_queue *, u64);
789 extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
790 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
791 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
792 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
793 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
794 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
795 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
796 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
797 extern int blk_queue_dma_drain(struct request_queue *q,
798 dma_drain_needed_fn *dma_drain_needed,
799 void *buf, unsigned int size);
800 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
801 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
802 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
803 extern void blk_queue_dma_alignment(struct request_queue *, int);
804 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
805 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
806 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
807 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
808 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
809 extern int blk_do_ordered(struct request_queue *, struct request **);
810 extern unsigned blk_ordered_cur_seq(struct request_queue *);
811 extern unsigned blk_ordered_req_seq(struct request *);
812 extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int);
814 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
815 extern void blk_dump_rq_flags(struct request *, char *);
816 extern void generic_unplug_device(struct request_queue *);
817 extern void __generic_unplug_device(struct request_queue *);
818 extern long nr_blockdev_pages(void);
820 int blk_get_queue(struct request_queue *);
821 struct request_queue *blk_alloc_queue(gfp_t);
822 struct request_queue *blk_alloc_queue_node(gfp_t, int);
823 extern void blk_put_queue(struct request_queue *);
828 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
829 extern int blk_queue_start_tag(struct request_queue *, struct request *);
830 extern struct request *blk_queue_find_tag(struct request_queue *, int);
831 extern void blk_queue_end_tag(struct request_queue *, struct request *);
832 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
833 extern void blk_queue_free_tags(struct request_queue *);
834 extern int blk_queue_resize_tags(struct request_queue *, int);
835 extern void blk_queue_invalidate_tags(struct request_queue *);
836 extern struct blk_queue_tag *blk_init_tags(int);
837 extern void blk_free_tags(struct blk_queue_tag *);
839 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
842 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
844 return bqt->tag_index[tag];
847 extern int blkdev_issue_flush(struct block_device *, sector_t *);
848 extern int blkdev_issue_discard(struct block_device *, sector_t sector,
851 static inline int sb_issue_discard(struct super_block *sb,
852 sector_t block, unsigned nr_blocks)
854 block <<= (sb->s_blocksize_bits - 9);
855 nr_blocks <<= (sb->s_blocksize_bits - 9);
856 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks);
860 * command filter functions
862 extern int blk_verify_command(struct blk_cmd_filter *filter,
863 unsigned char *cmd, int has_write_perm);
864 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
866 #define MAX_PHYS_SEGMENTS 128
867 #define MAX_HW_SEGMENTS 128
868 #define SAFE_MAX_SECTORS 255
869 #define BLK_DEF_MAX_SECTORS 1024
871 #define MAX_SEGMENT_SIZE 65536
873 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
875 static inline int queue_hardsect_size(struct request_queue *q)
879 if (q && q->hardsect_size)
880 retval = q->hardsect_size;
885 static inline int bdev_hardsect_size(struct block_device *bdev)
887 return queue_hardsect_size(bdev_get_queue(bdev));
890 static inline int queue_dma_alignment(struct request_queue *q)
892 return q ? q->dma_alignment : 511;
895 /* assumes size > 256 */
896 static inline unsigned int blksize_bits(unsigned int size)
898 unsigned int bits = 8;
902 } while (size > 256);
906 static inline unsigned int block_size(struct block_device *bdev)
908 return bdev->bd_block_size;
911 typedef struct {struct page *v;} Sector;
913 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
915 static inline void put_dev_sector(Sector p)
917 page_cache_release(p.v);
921 int kblockd_schedule_work(struct work_struct *work);
922 void kblockd_flush_work(struct work_struct *work);
924 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
925 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
926 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
927 MODULE_ALIAS("block-major-" __stringify(major) "-*")
929 #if defined(CONFIG_BLK_DEV_INTEGRITY)
931 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
932 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
934 struct blk_integrity_exchg {
938 unsigned int data_size;
939 unsigned short sector_size;
940 const char *disk_name;
943 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
944 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
945 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
946 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
948 struct blk_integrity {
949 integrity_gen_fn *generate_fn;
950 integrity_vrfy_fn *verify_fn;
951 integrity_set_tag_fn *set_tag_fn;
952 integrity_get_tag_fn *get_tag_fn;
954 unsigned short flags;
955 unsigned short tuple_size;
956 unsigned short sector_size;
957 unsigned short tag_size;
964 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
965 extern void blk_integrity_unregister(struct gendisk *);
966 extern int blk_integrity_compare(struct block_device *, struct block_device *);
967 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
968 extern int blk_rq_count_integrity_sg(struct request *);
970 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
973 return bi->tuple_size;
978 static inline struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
980 return bdev->bd_disk->integrity;
983 static inline unsigned int bdev_get_tag_size(struct block_device *bdev)
985 struct blk_integrity *bi = bdev_get_integrity(bdev);
993 static inline int bdev_integrity_enabled(struct block_device *bdev, int rw)
995 struct blk_integrity *bi = bdev_get_integrity(bdev);
1000 if (rw == READ && bi->verify_fn != NULL &&
1001 (bi->flags & INTEGRITY_FLAG_READ))
1004 if (rw == WRITE && bi->generate_fn != NULL &&
1005 (bi->flags & INTEGRITY_FLAG_WRITE))
1011 static inline int blk_integrity_rq(struct request *rq)
1013 if (rq->bio == NULL)
1016 return bio_integrity(rq->bio);
1019 #else /* CONFIG_BLK_DEV_INTEGRITY */
1021 #define blk_integrity_rq(rq) (0)
1022 #define blk_rq_count_integrity_sg(a) (0)
1023 #define blk_rq_map_integrity_sg(a, b) (0)
1024 #define bdev_get_integrity(a) (0)
1025 #define bdev_get_tag_size(a) (0)
1026 #define blk_integrity_compare(a, b) (0)
1027 #define blk_integrity_register(a, b) (0)
1028 #define blk_integrity_unregister(a) do { } while (0);
1030 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1032 #else /* CONFIG_BLOCK */
1034 * stubs for when the block layer is configured out
1036 #define buffer_heads_over_limit 0
1038 static inline long nr_blockdev_pages(void)
1043 #endif /* CONFIG_BLOCK */