1 #ifndef _LINUX_BLKDEV_H
2 #define _LINUX_BLKDEV_H
6 #include <linux/sched.h>
7 #include <linux/major.h>
8 #include <linux/genhd.h>
9 #include <linux/list.h>
10 #include <linux/timer.h>
11 #include <linux/workqueue.h>
12 #include <linux/pagemap.h>
13 #include <linux/backing-dev.h>
14 #include <linux/wait.h>
15 #include <linux/mempool.h>
16 #include <linux/bio.h>
17 #include <linux/module.h>
18 #include <linux/stringify.h>
19 #include <linux/gfp.h>
20 #include <linux/bsg.h>
21 #include <linux/smp.h>
23 #include <asm/scatterlist.h>
25 struct scsi_ioctl_command;
28 struct elevator_queue;
29 typedef struct elevator_queue elevator_t;
30 struct request_pm_state;
35 #define BLKDEV_MIN_RQ 4
36 #define BLKDEV_MAX_RQ 128 /* Default maximum */
39 typedef void (rq_end_io_fn)(struct request *, int);
46 wait_queue_head_t wait[2];
50 * request command types
52 enum rq_cmd_type_bits {
53 REQ_TYPE_FS = 1, /* fs request */
54 REQ_TYPE_BLOCK_PC, /* scsi command */
55 REQ_TYPE_SENSE, /* sense request */
56 REQ_TYPE_PM_SUSPEND, /* suspend request */
57 REQ_TYPE_PM_RESUME, /* resume request */
58 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
59 REQ_TYPE_SPECIAL, /* driver defined type */
60 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
62 * for ATA/ATAPI devices. this really doesn't belong here, ide should
63 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
64 * private REQ_LB opcodes to differentiate what type of request this is
66 REQ_TYPE_ATA_TASKFILE,
71 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
72 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
75 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
76 * typically to differentiate REQ_TYPE_SPECIAL requests.
80 REQ_LB_OP_EJECT = 0x40, /* eject request */
81 REQ_LB_OP_FLUSH = 0x41, /* flush request */
82 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
86 * request type modified bits. first two bits match BIO_RW* bits, important
89 __REQ_RW, /* not set, read. set, write */
90 __REQ_FAILFAST, /* no low level driver retries */
91 __REQ_DISCARD, /* request to discard sectors */
92 __REQ_SORTED, /* elevator knows about this request */
93 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
94 __REQ_HARDBARRIER, /* may not be passed by drive either */
95 __REQ_FUA, /* forced unit access */
96 __REQ_NOMERGE, /* don't touch this for merging */
97 __REQ_STARTED, /* drive already may have started this one */
98 __REQ_DONTPREP, /* don't call prep for this one */
99 __REQ_QUEUED, /* uses queueing */
100 __REQ_ELVPRIV, /* elevator private data attached */
101 __REQ_FAILED, /* set if the request failed */
102 __REQ_QUIET, /* don't worry about errors */
103 __REQ_PREEMPT, /* set for "ide_preempt" requests */
104 __REQ_ORDERED_COLOR, /* is before or after barrier */
105 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
106 __REQ_ALLOCED, /* request came from our alloc pool */
107 __REQ_RW_META, /* metadata io request */
108 __REQ_COPY_USER, /* contains copies of user pages */
109 __REQ_INTEGRITY, /* integrity metadata has been remapped */
110 __REQ_NR_BITS, /* stops here */
113 #define REQ_RW (1 << __REQ_RW)
114 #define REQ_DISCARD (1 << __REQ_DISCARD)
115 #define REQ_FAILFAST (1 << __REQ_FAILFAST)
116 #define REQ_SORTED (1 << __REQ_SORTED)
117 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
118 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
119 #define REQ_FUA (1 << __REQ_FUA)
120 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
121 #define REQ_STARTED (1 << __REQ_STARTED)
122 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
123 #define REQ_QUEUED (1 << __REQ_QUEUED)
124 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
125 #define REQ_FAILED (1 << __REQ_FAILED)
126 #define REQ_QUIET (1 << __REQ_QUIET)
127 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
128 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
129 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
130 #define REQ_ALLOCED (1 << __REQ_ALLOCED)
131 #define REQ_RW_META (1 << __REQ_RW_META)
132 #define REQ_COPY_USER (1 << __REQ_COPY_USER)
133 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
135 #define BLK_MAX_CDB 16
138 * try to put the fields that are referenced together in the same cacheline.
139 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
143 struct list_head queuelist;
144 struct call_single_data csd;
147 struct request_queue *q;
149 unsigned int cmd_flags;
150 enum rq_cmd_type_bits cmd_type;
151 unsigned long atomic_flags;
153 /* Maintain bio traversal state for part by part I/O submission.
154 * hard_* are block layer internals, no driver should touch them!
157 sector_t sector; /* next sector to submit */
158 sector_t hard_sector; /* next sector to complete */
159 unsigned long nr_sectors; /* no. of sectors left to submit */
160 unsigned long hard_nr_sectors; /* no. of sectors left to complete */
161 /* no. of sectors left to submit in the current segment */
162 unsigned int current_nr_sectors;
164 /* no. of sectors left to complete in the current segment */
165 unsigned int hard_cur_sectors;
170 struct hlist_node hash; /* merge hash */
172 * The rb_node is only used inside the io scheduler, requests
173 * are pruned when moved to the dispatch queue. So let the
174 * completion_data share space with the rb_node.
177 struct rb_node rb_node; /* sort/lookup */
178 void *completion_data;
182 * two pointers are available for the IO schedulers, if they need
183 * more they have to dynamically allocate it.
185 void *elevator_private;
186 void *elevator_private2;
188 struct gendisk *rq_disk;
189 unsigned long start_time;
191 /* Number of scatter-gather DMA addr+len pairs after
192 * physical address coalescing is performed.
194 unsigned short nr_phys_segments;
196 unsigned short ioprio;
207 * when request is used as a packet command carrier
209 unsigned short cmd_len;
210 unsigned char __cmd[BLK_MAX_CDB];
213 unsigned int data_len;
214 unsigned int extra_len; /* length of alignment and padding */
215 unsigned int sense_len;
219 unsigned long deadline;
220 struct list_head timeout_list;
221 unsigned int timeout;
225 * completion callback.
227 rq_end_io_fn *end_io;
231 struct request *next_rq;
234 static inline unsigned short req_get_ioprio(struct request *req)
240 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
241 * requests. Some step values could eventually be made generic.
243 struct request_pm_state
245 /* PM state machine step value, currently driver specific */
247 /* requested PM state value (S1, S2, S3, S4, ...) */
249 void* data; /* for driver use */
252 #include <linux/elevator.h>
254 typedef void (request_fn_proc) (struct request_queue *q);
255 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
256 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
257 typedef void (unplug_fn) (struct request_queue *);
258 typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
261 struct bvec_merge_data {
262 struct block_device *bi_bdev;
267 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
269 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
270 typedef void (softirq_done_fn)(struct request *);
271 typedef int (dma_drain_needed_fn)(struct request *);
273 enum blk_eh_timer_return {
279 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
281 enum blk_queue_state {
286 struct blk_queue_tag {
287 struct request **tag_index; /* map of busy tags */
288 unsigned long *tag_map; /* bit map of free/busy tags */
289 int busy; /* current depth */
290 int max_depth; /* what we will send to device */
291 int real_max_depth; /* what the array can hold */
292 atomic_t refcnt; /* map can be shared */
295 #define BLK_SCSI_MAX_CMDS (256)
296 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
298 struct blk_cmd_filter {
299 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
300 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
307 * Together with queue_head for cacheline sharing
309 struct list_head queue_head;
310 struct request *last_merge;
311 elevator_t *elevator;
314 * the queue request freelist, one for reads and one for writes
316 struct request_list rq;
318 request_fn_proc *request_fn;
319 make_request_fn *make_request_fn;
320 prep_rq_fn *prep_rq_fn;
321 unplug_fn *unplug_fn;
322 prepare_discard_fn *prepare_discard_fn;
323 merge_bvec_fn *merge_bvec_fn;
324 prepare_flush_fn *prepare_flush_fn;
325 softirq_done_fn *softirq_done_fn;
326 rq_timed_out_fn *rq_timed_out_fn;
327 dma_drain_needed_fn *dma_drain_needed;
330 * Dispatch queue sorting
333 struct request *boundary_rq;
336 * Auto-unplugging state
338 struct timer_list unplug_timer;
339 int unplug_thresh; /* After this many requests */
340 unsigned long unplug_delay; /* After this many jiffies */
341 struct work_struct unplug_work;
343 struct backing_dev_info backing_dev_info;
346 * The queue owner gets to use this for whatever they like.
347 * ll_rw_blk doesn't touch it.
352 * queue needs bounce pages for pages above this limit
354 unsigned long bounce_pfn;
358 * various queue flags, see QUEUE_* below
360 unsigned long queue_flags;
363 * protects queue structures from reentrancy. ->__queue_lock should
364 * _never_ be used directly, it is queue private. always use
367 spinlock_t __queue_lock;
368 spinlock_t *queue_lock;
378 unsigned long nr_requests; /* Max # of requests */
379 unsigned int nr_congestion_on;
380 unsigned int nr_congestion_off;
381 unsigned int nr_batching;
383 unsigned int max_sectors;
384 unsigned int max_hw_sectors;
385 unsigned short max_phys_segments;
386 unsigned short max_hw_segments;
387 unsigned short hardsect_size;
388 unsigned int max_segment_size;
390 unsigned long seg_boundary_mask;
391 void *dma_drain_buffer;
392 unsigned int dma_drain_size;
393 unsigned int dma_pad_mask;
394 unsigned int dma_alignment;
396 struct blk_queue_tag *queue_tags;
397 struct list_head tag_busy_list;
399 unsigned int nr_sorted;
400 unsigned int in_flight;
402 unsigned int rq_timeout;
403 struct timer_list timeout;
404 struct list_head timeout_list;
409 unsigned int sg_timeout;
410 unsigned int sg_reserved_size;
412 #ifdef CONFIG_BLK_DEV_IO_TRACE
413 struct blk_trace *blk_trace;
416 * reserved for flush operations
418 unsigned int ordered, next_ordered, ordseq;
419 int orderr, ordcolor;
420 struct request pre_flush_rq, bar_rq, post_flush_rq;
421 struct request *orig_bar_rq;
423 struct mutex sysfs_lock;
425 #if defined(CONFIG_BLK_DEV_BSG)
426 struct bsg_class_device bsg_dev;
428 struct blk_cmd_filter cmd_filter;
431 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
432 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
433 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
434 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */
435 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */
436 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
437 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
438 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
439 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
440 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
441 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
442 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
443 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
445 static inline int queue_is_locked(struct request_queue *q)
448 spinlock_t *lock = q->queue_lock;
449 return lock && spin_is_locked(lock);
455 static inline void queue_flag_set_unlocked(unsigned int flag,
456 struct request_queue *q)
458 __set_bit(flag, &q->queue_flags);
461 static inline int queue_flag_test_and_clear(unsigned int flag,
462 struct request_queue *q)
464 WARN_ON_ONCE(!queue_is_locked(q));
466 if (test_bit(flag, &q->queue_flags)) {
467 __clear_bit(flag, &q->queue_flags);
474 static inline int queue_flag_test_and_set(unsigned int flag,
475 struct request_queue *q)
477 WARN_ON_ONCE(!queue_is_locked(q));
479 if (!test_bit(flag, &q->queue_flags)) {
480 __set_bit(flag, &q->queue_flags);
487 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
489 WARN_ON_ONCE(!queue_is_locked(q));
490 __set_bit(flag, &q->queue_flags);
493 static inline void queue_flag_clear_unlocked(unsigned int flag,
494 struct request_queue *q)
496 __clear_bit(flag, &q->queue_flags);
499 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
501 WARN_ON_ONCE(!queue_is_locked(q));
502 __clear_bit(flag, &q->queue_flags);
507 * Hardbarrier is supported with one of the following methods.
509 * NONE : hardbarrier unsupported
510 * DRAIN : ordering by draining is enough
511 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
512 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
513 * TAG : ordering by tag is enough
514 * TAG_FLUSH : ordering by tag w/ pre and post flushes
515 * TAG_FUA : ordering by tag w/ pre flush and FUA write
517 QUEUE_ORDERED_NONE = 0x00,
518 QUEUE_ORDERED_DRAIN = 0x01,
519 QUEUE_ORDERED_TAG = 0x02,
521 QUEUE_ORDERED_PREFLUSH = 0x10,
522 QUEUE_ORDERED_POSTFLUSH = 0x20,
523 QUEUE_ORDERED_FUA = 0x40,
525 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
526 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
527 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
528 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
529 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
530 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
531 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
532 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
535 * Ordered operation sequence
537 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
538 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
539 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
540 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
541 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
542 QUEUE_ORDSEQ_DONE = 0x20,
545 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
546 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
547 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
548 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
549 #define blk_queue_flushing(q) ((q)->ordseq)
551 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
552 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
553 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
554 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
556 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST)
557 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
559 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
561 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
562 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
563 #define blk_pm_request(rq) \
564 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
566 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
567 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
568 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
569 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
570 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
571 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
572 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
573 /* rq->queuelist of dequeued request must be list_empty() */
574 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
576 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
578 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
581 * We regard a request as sync, if it's a READ or a SYNC write.
583 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)
584 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
586 static inline int blk_queue_full(struct request_queue *q, int rw)
589 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
590 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
593 static inline void blk_set_queue_full(struct request_queue *q, int rw)
596 queue_flag_set(QUEUE_FLAG_READFULL, q);
598 queue_flag_set(QUEUE_FLAG_WRITEFULL, q);
601 static inline void blk_clear_queue_full(struct request_queue *q, int rw)
604 queue_flag_clear(QUEUE_FLAG_READFULL, q);
606 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q);
611 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
612 * it already be started by driver.
614 #define RQ_NOMERGE_FLAGS \
615 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
616 #define rq_mergeable(rq) \
617 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
618 (blk_discard_rq(rq) || blk_fs_request((rq))))
621 * q->prep_rq_fn return values
623 #define BLKPREP_OK 0 /* serve it */
624 #define BLKPREP_KILL 1 /* fatal error, kill */
625 #define BLKPREP_DEFER 2 /* leave on queue */
627 extern unsigned long blk_max_low_pfn, blk_max_pfn;
630 * standard bounce addresses:
632 * BLK_BOUNCE_HIGH : bounce all highmem pages
633 * BLK_BOUNCE_ANY : don't bounce anything
634 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
637 #if BITS_PER_LONG == 32
638 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
640 #define BLK_BOUNCE_HIGH -1ULL
642 #define BLK_BOUNCE_ANY (-1ULL)
643 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
646 * default timeout for SG_IO if none specified
648 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
651 extern int init_emergency_isa_pool(void);
652 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
654 static inline int init_emergency_isa_pool(void)
658 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
661 #endif /* CONFIG_MMU */
669 struct req_iterator {
674 /* This should not be used directly - use rq_for_each_segment */
675 #define __rq_for_each_bio(_bio, rq) \
677 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
679 #define rq_for_each_segment(bvl, _rq, _iter) \
680 __rq_for_each_bio(_iter.bio, _rq) \
681 bio_for_each_segment(bvl, _iter.bio, _iter.i)
683 #define rq_iter_last(rq, _iter) \
684 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
686 extern int blk_register_queue(struct gendisk *disk);
687 extern void blk_unregister_queue(struct gendisk *disk);
688 extern void register_disk(struct gendisk *dev);
689 extern void generic_make_request(struct bio *bio);
690 extern void blk_rq_init(struct request_queue *q, struct request *rq);
691 extern void blk_put_request(struct request *);
692 extern void __blk_put_request(struct request_queue *, struct request *);
693 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
694 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
695 extern void blk_requeue_request(struct request_queue *, struct request *);
696 extern void blk_plug_device(struct request_queue *);
697 extern void blk_plug_device_unlocked(struct request_queue *);
698 extern int blk_remove_plug(struct request_queue *);
699 extern void blk_recount_segments(struct request_queue *, struct bio *);
700 extern int scsi_cmd_ioctl(struct file *, struct request_queue *,
701 struct gendisk *, unsigned int, void __user *);
702 extern int sg_scsi_ioctl(struct file *, struct request_queue *,
703 struct gendisk *, struct scsi_ioctl_command __user *);
706 * Temporary export, until SCSI gets fixed up.
708 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
712 * A queue has just exitted congestion. Note this in the global counter of
713 * congested queues, and wake up anyone who was waiting for requests to be
716 static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
718 clear_bdi_congested(&q->backing_dev_info, rw);
722 * A queue has just entered congestion. Flag that in the queue's VM-visible
723 * state flags and increment the global gounter of congested queues.
725 static inline void blk_set_queue_congested(struct request_queue *q, int rw)
727 set_bdi_congested(&q->backing_dev_info, rw);
730 extern void blk_start_queue(struct request_queue *q);
731 extern void blk_stop_queue(struct request_queue *q);
732 extern void blk_sync_queue(struct request_queue *q);
733 extern void __blk_stop_queue(struct request_queue *q);
734 extern void __blk_run_queue(struct request_queue *);
735 extern void blk_run_queue(struct request_queue *);
736 extern void blk_start_queueing(struct request_queue *);
737 extern int blk_rq_map_user(struct request_queue *, struct request *,
738 struct rq_map_data *, void __user *, unsigned long,
740 extern int blk_rq_unmap_user(struct bio *);
741 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
742 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
743 struct rq_map_data *, struct sg_iovec *, int,
744 unsigned int, gfp_t);
745 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
746 struct request *, int);
747 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
748 struct request *, int, rq_end_io_fn *);
749 extern void blk_unplug(struct request_queue *q);
751 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
753 return bdev->bd_disk->queue;
756 static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
759 if (bdi && bdi->unplug_io_fn)
760 bdi->unplug_io_fn(bdi, page);
763 static inline void blk_run_address_space(struct address_space *mapping)
766 blk_run_backing_dev(mapping->backing_dev_info, NULL);
770 * blk_end_request() and friends.
771 * __blk_end_request() and end_request() must be called with
772 * the request queue spinlock acquired.
774 * Several drivers define their own end_request and call
775 * blk_end_request() for parts of the original function.
776 * This prevents code duplication in drivers.
778 extern int blk_end_request(struct request *rq, int error,
779 unsigned int nr_bytes);
780 extern int __blk_end_request(struct request *rq, int error,
781 unsigned int nr_bytes);
782 extern int blk_end_bidi_request(struct request *rq, int error,
783 unsigned int nr_bytes, unsigned int bidi_bytes);
784 extern void end_request(struct request *, int);
785 extern void end_queued_request(struct request *, int);
786 extern void end_dequeued_request(struct request *, int);
787 extern int blk_end_request_callback(struct request *rq, int error,
788 unsigned int nr_bytes,
789 int (drv_callback)(struct request *));
790 extern void blk_complete_request(struct request *);
791 extern void __blk_complete_request(struct request *);
792 extern void blk_abort_request(struct request *);
793 extern void blk_abort_queue(struct request_queue *);
796 * blk_end_request() takes bytes instead of sectors as a complete size.
797 * blk_rq_bytes() returns bytes left to complete in the entire request.
798 * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
800 extern unsigned int blk_rq_bytes(struct request *rq);
801 extern unsigned int blk_rq_cur_bytes(struct request *rq);
803 static inline void blkdev_dequeue_request(struct request *req)
805 elv_dequeue_request(req->q, req);
809 * Access functions for manipulating queue properties
811 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
812 spinlock_t *lock, int node_id);
813 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
814 extern void blk_cleanup_queue(struct request_queue *);
815 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
816 extern void blk_queue_bounce_limit(struct request_queue *, u64);
817 extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
818 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
819 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
820 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
821 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
822 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
823 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
824 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
825 extern int blk_queue_dma_drain(struct request_queue *q,
826 dma_drain_needed_fn *dma_drain_needed,
827 void *buf, unsigned int size);
828 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
829 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
830 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
831 extern void blk_queue_dma_alignment(struct request_queue *, int);
832 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
833 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
834 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
835 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
836 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
837 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
838 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
839 extern int blk_do_ordered(struct request_queue *, struct request **);
840 extern unsigned blk_ordered_cur_seq(struct request_queue *);
841 extern unsigned blk_ordered_req_seq(struct request *);
842 extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int);
844 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
845 extern void blk_dump_rq_flags(struct request *, char *);
846 extern void generic_unplug_device(struct request_queue *);
847 extern void __generic_unplug_device(struct request_queue *);
848 extern long nr_blockdev_pages(void);
850 int blk_get_queue(struct request_queue *);
851 struct request_queue *blk_alloc_queue(gfp_t);
852 struct request_queue *blk_alloc_queue_node(gfp_t, int);
853 extern void blk_put_queue(struct request_queue *);
858 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
859 extern int blk_queue_start_tag(struct request_queue *, struct request *);
860 extern struct request *blk_queue_find_tag(struct request_queue *, int);
861 extern void blk_queue_end_tag(struct request_queue *, struct request *);
862 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
863 extern void blk_queue_free_tags(struct request_queue *);
864 extern int blk_queue_resize_tags(struct request_queue *, int);
865 extern void blk_queue_invalidate_tags(struct request_queue *);
866 extern struct blk_queue_tag *blk_init_tags(int);
867 extern void blk_free_tags(struct blk_queue_tag *);
869 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
872 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
874 return bqt->tag_index[tag];
877 extern int blkdev_issue_flush(struct block_device *, sector_t *);
878 extern int blkdev_issue_discard(struct block_device *,
879 sector_t sector, sector_t nr_sects, gfp_t);
881 static inline int sb_issue_discard(struct super_block *sb,
882 sector_t block, sector_t nr_blocks)
884 block <<= (sb->s_blocksize_bits - 9);
885 nr_blocks <<= (sb->s_blocksize_bits - 9);
886 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
890 * command filter functions
892 extern int blk_verify_command(struct blk_cmd_filter *filter,
893 unsigned char *cmd, int has_write_perm);
894 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
896 #define MAX_PHYS_SEGMENTS 128
897 #define MAX_HW_SEGMENTS 128
898 #define SAFE_MAX_SECTORS 255
899 #define BLK_DEF_MAX_SECTORS 1024
901 #define MAX_SEGMENT_SIZE 65536
903 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
905 static inline int queue_hardsect_size(struct request_queue *q)
909 if (q && q->hardsect_size)
910 retval = q->hardsect_size;
915 static inline int bdev_hardsect_size(struct block_device *bdev)
917 return queue_hardsect_size(bdev_get_queue(bdev));
920 static inline int queue_dma_alignment(struct request_queue *q)
922 return q ? q->dma_alignment : 511;
925 static inline int blk_rq_aligned(struct request_queue *q, void *addr,
928 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
929 return !((unsigned long)addr & alignment) && !(len & alignment);
932 /* assumes size > 256 */
933 static inline unsigned int blksize_bits(unsigned int size)
935 unsigned int bits = 8;
939 } while (size > 256);
943 static inline unsigned int block_size(struct block_device *bdev)
945 return bdev->bd_block_size;
948 typedef struct {struct page *v;} Sector;
950 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
952 static inline void put_dev_sector(Sector p)
954 page_cache_release(p.v);
958 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
959 void kblockd_flush_work(struct work_struct *work);
961 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
962 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
963 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
964 MODULE_ALIAS("block-major-" __stringify(major) "-*")
966 #if defined(CONFIG_BLK_DEV_INTEGRITY)
968 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
969 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
971 struct blk_integrity_exchg {
975 unsigned int data_size;
976 unsigned short sector_size;
977 const char *disk_name;
980 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
981 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
982 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
983 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
985 struct blk_integrity {
986 integrity_gen_fn *generate_fn;
987 integrity_vrfy_fn *verify_fn;
988 integrity_set_tag_fn *set_tag_fn;
989 integrity_get_tag_fn *get_tag_fn;
991 unsigned short flags;
992 unsigned short tuple_size;
993 unsigned short sector_size;
994 unsigned short tag_size;
1001 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1002 extern void blk_integrity_unregister(struct gendisk *);
1003 extern int blk_integrity_compare(struct block_device *, struct block_device *);
1004 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1005 extern int blk_rq_count_integrity_sg(struct request *);
1007 static inline int blk_integrity_rq(struct request *rq)
1009 if (rq->bio == NULL)
1012 return bio_integrity(rq->bio);
1015 #else /* CONFIG_BLK_DEV_INTEGRITY */
1017 #define blk_integrity_rq(rq) (0)
1018 #define blk_rq_count_integrity_sg(a) (0)
1019 #define blk_rq_map_integrity_sg(a, b) (0)
1020 #define blk_integrity_compare(a, b) (0)
1021 #define blk_integrity_register(a, b) (0)
1022 #define blk_integrity_unregister(a) do { } while (0);
1024 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1026 #else /* CONFIG_BLOCK */
1028 * stubs for when the block layer is configured out
1030 #define buffer_heads_over_limit 0
1032 static inline long nr_blockdev_pages(void)
1037 #endif /* CONFIG_BLOCK */