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 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);
42 * count[], starved[], and wait[] are indexed by
43 * BLK_RW_SYNC/BLK_RW_ASYNC
49 wait_queue_head_t wait[2];
53 * request command types
55 enum rq_cmd_type_bits {
56 REQ_TYPE_FS = 1, /* fs request */
57 REQ_TYPE_BLOCK_PC, /* scsi command */
58 REQ_TYPE_SENSE, /* sense request */
59 REQ_TYPE_PM_SUSPEND, /* suspend request */
60 REQ_TYPE_PM_RESUME, /* resume request */
61 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
62 REQ_TYPE_SPECIAL, /* driver defined type */
63 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */
65 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 * private REQ_LB opcodes to differentiate what type of request this is
69 REQ_TYPE_ATA_TASKFILE,
79 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being
80 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a
83 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need,
84 * typically to differentiate REQ_TYPE_SPECIAL requests.
88 REQ_LB_OP_EJECT = 0x40, /* eject request */
89 REQ_LB_OP_FLUSH = 0x41, /* flush request */
90 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */
94 * request type modified bits. first two bits match BIO_RW* bits, important
97 __REQ_RW, /* not set, read. set, write */
98 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
99 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
100 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
101 __REQ_DISCARD, /* request to discard sectors */
102 __REQ_SORTED, /* elevator knows about this request */
103 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
104 __REQ_HARDBARRIER, /* may not be passed by drive either */
105 __REQ_FUA, /* forced unit access */
106 __REQ_NOMERGE, /* don't touch this for merging */
107 __REQ_STARTED, /* drive already may have started this one */
108 __REQ_DONTPREP, /* don't call prep for this one */
109 __REQ_QUEUED, /* uses queueing */
110 __REQ_ELVPRIV, /* elevator private data attached */
111 __REQ_FAILED, /* set if the request failed */
112 __REQ_QUIET, /* don't worry about errors */
113 __REQ_PREEMPT, /* set for "ide_preempt" requests */
114 __REQ_ORDERED_COLOR, /* is before or after barrier */
115 __REQ_RW_SYNC, /* request is sync (sync write or read) */
116 __REQ_ALLOCED, /* request came from our alloc pool */
117 __REQ_RW_META, /* metadata io request */
118 __REQ_COPY_USER, /* contains copies of user pages */
119 __REQ_INTEGRITY, /* integrity metadata has been remapped */
120 __REQ_NOIDLE, /* Don't anticipate more IO after this one */
121 __REQ_IO_STAT, /* account I/O stat */
122 __REQ_NR_BITS, /* stops here */
125 #define REQ_RW (1 << __REQ_RW)
126 #define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV)
127 #define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
128 #define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
129 #define REQ_DISCARD (1 << __REQ_DISCARD)
130 #define REQ_SORTED (1 << __REQ_SORTED)
131 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
132 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
133 #define REQ_FUA (1 << __REQ_FUA)
134 #define REQ_NOMERGE (1 << __REQ_NOMERGE)
135 #define REQ_STARTED (1 << __REQ_STARTED)
136 #define REQ_DONTPREP (1 << __REQ_DONTPREP)
137 #define REQ_QUEUED (1 << __REQ_QUEUED)
138 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
139 #define REQ_FAILED (1 << __REQ_FAILED)
140 #define REQ_QUIET (1 << __REQ_QUIET)
141 #define REQ_PREEMPT (1 << __REQ_PREEMPT)
142 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
143 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
144 #define REQ_ALLOCED (1 << __REQ_ALLOCED)
145 #define REQ_RW_META (1 << __REQ_RW_META)
146 #define REQ_COPY_USER (1 << __REQ_COPY_USER)
147 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
148 #define REQ_NOIDLE (1 << __REQ_NOIDLE)
149 #define REQ_IO_STAT (1 << __REQ_IO_STAT)
151 #define BLK_MAX_CDB 16
154 * try to put the fields that are referenced together in the same cacheline.
155 * if you modify this structure, be sure to check block/blk-core.c:rq_init()
159 struct list_head queuelist;
160 struct call_single_data csd;
163 struct request_queue *q;
165 unsigned int cmd_flags;
166 enum rq_cmd_type_bits cmd_type;
167 unsigned long atomic_flags;
169 sector_t sector; /* sector cursor */
170 unsigned int data_len; /* total data len, don't access directly */
175 struct hlist_node hash; /* merge hash */
177 * The rb_node is only used inside the io scheduler, requests
178 * are pruned when moved to the dispatch queue. So let the
179 * completion_data share space with the rb_node.
182 struct rb_node rb_node; /* sort/lookup */
183 void *completion_data;
187 * two pointers are available for the IO schedulers, if they need
188 * more they have to dynamically allocate it.
190 void *elevator_private;
191 void *elevator_private2;
193 struct gendisk *rq_disk;
194 unsigned long start_time;
196 /* Number of scatter-gather DMA addr+len pairs after
197 * physical address coalescing is performed.
199 unsigned short nr_phys_segments;
201 unsigned short ioprio;
203 void *special; /* opaque pointer available for LLD use */
204 char *buffer; /* kaddr of the current segment if available */
212 * when request is used as a packet command carrier
214 unsigned short cmd_len;
215 unsigned char __cmd[BLK_MAX_CDB];
218 unsigned int extra_len; /* length of alignment and padding */
219 unsigned int sense_len;
220 unsigned int resid_len; /* residual count */
223 unsigned long deadline;
224 struct list_head timeout_list;
225 unsigned int timeout;
229 * completion callback.
231 rq_end_io_fn *end_io;
235 struct request *next_rq;
238 static inline unsigned short req_get_ioprio(struct request *req)
244 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
245 * requests. Some step values could eventually be made generic.
247 struct request_pm_state
249 /* PM state machine step value, currently driver specific */
251 /* requested PM state value (S1, S2, S3, S4, ...) */
253 void* data; /* for driver use */
256 #include <linux/elevator.h>
258 typedef void (request_fn_proc) (struct request_queue *q);
259 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
260 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
261 typedef void (unplug_fn) (struct request_queue *);
262 typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
265 struct bvec_merge_data {
266 struct block_device *bi_bdev;
271 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
273 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
274 typedef void (softirq_done_fn)(struct request *);
275 typedef int (dma_drain_needed_fn)(struct request *);
276 typedef int (lld_busy_fn) (struct request_queue *q);
278 enum blk_eh_timer_return {
284 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
286 enum blk_queue_state {
291 struct blk_queue_tag {
292 struct request **tag_index; /* map of busy tags */
293 unsigned long *tag_map; /* bit map of free/busy tags */
294 int busy; /* current depth */
295 int max_depth; /* what we will send to device */
296 int real_max_depth; /* what the array can hold */
297 atomic_t refcnt; /* map can be shared */
300 #define BLK_SCSI_MAX_CMDS (256)
301 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
303 struct blk_cmd_filter {
304 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
305 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
312 * Together with queue_head for cacheline sharing
314 struct list_head queue_head;
315 struct request *last_merge;
316 struct elevator_queue *elevator;
319 * the queue request freelist, one for reads and one for writes
321 struct request_list rq;
323 request_fn_proc *request_fn;
324 make_request_fn *make_request_fn;
325 prep_rq_fn *prep_rq_fn;
326 unplug_fn *unplug_fn;
327 prepare_discard_fn *prepare_discard_fn;
328 merge_bvec_fn *merge_bvec_fn;
329 prepare_flush_fn *prepare_flush_fn;
330 softirq_done_fn *softirq_done_fn;
331 rq_timed_out_fn *rq_timed_out_fn;
332 dma_drain_needed_fn *dma_drain_needed;
333 lld_busy_fn *lld_busy_fn;
336 * Dispatch queue sorting
339 struct request *boundary_rq;
342 * Auto-unplugging state
344 struct timer_list unplug_timer;
345 int unplug_thresh; /* After this many requests */
346 unsigned long unplug_delay; /* After this many jiffies */
347 struct work_struct unplug_work;
349 struct backing_dev_info backing_dev_info;
352 * The queue owner gets to use this for whatever they like.
353 * ll_rw_blk doesn't touch it.
358 * queue needs bounce pages for pages above this limit
360 unsigned long bounce_pfn;
364 * various queue flags, see QUEUE_* below
366 unsigned long queue_flags;
369 * protects queue structures from reentrancy. ->__queue_lock should
370 * _never_ be used directly, it is queue private. always use
373 spinlock_t __queue_lock;
374 spinlock_t *queue_lock;
384 unsigned long nr_requests; /* Max # of requests */
385 unsigned int nr_congestion_on;
386 unsigned int nr_congestion_off;
387 unsigned int nr_batching;
389 unsigned int max_sectors;
390 unsigned int max_hw_sectors;
391 unsigned short max_phys_segments;
392 unsigned short max_hw_segments;
393 unsigned short hardsect_size;
394 unsigned int max_segment_size;
396 unsigned long seg_boundary_mask;
397 void *dma_drain_buffer;
398 unsigned int dma_drain_size;
399 unsigned int dma_pad_mask;
400 unsigned int dma_alignment;
402 struct blk_queue_tag *queue_tags;
403 struct list_head tag_busy_list;
405 unsigned int nr_sorted;
406 unsigned int in_flight;
408 unsigned int rq_timeout;
409 struct timer_list timeout;
410 struct list_head timeout_list;
415 unsigned int sg_timeout;
416 unsigned int sg_reserved_size;
418 #ifdef CONFIG_BLK_DEV_IO_TRACE
419 struct blk_trace *blk_trace;
422 * reserved for flush operations
424 unsigned int ordered, next_ordered, ordseq;
425 int orderr, ordcolor;
426 struct request pre_flush_rq, bar_rq, post_flush_rq;
427 struct request *orig_bar_rq;
429 struct mutex sysfs_lock;
431 #if defined(CONFIG_BLK_DEV_BSG)
432 struct bsg_class_device bsg_dev;
434 struct blk_cmd_filter cmd_filter;
437 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
438 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
439 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
440 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
441 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
442 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
443 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
444 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
445 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
446 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
447 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
448 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
449 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
450 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
451 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
452 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
453 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
455 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
456 (1 << QUEUE_FLAG_CLUSTER) | \
457 (1 << QUEUE_FLAG_STACKABLE))
459 static inline int queue_is_locked(struct request_queue *q)
462 spinlock_t *lock = q->queue_lock;
463 return lock && spin_is_locked(lock);
469 static inline void queue_flag_set_unlocked(unsigned int flag,
470 struct request_queue *q)
472 __set_bit(flag, &q->queue_flags);
475 static inline int queue_flag_test_and_clear(unsigned int flag,
476 struct request_queue *q)
478 WARN_ON_ONCE(!queue_is_locked(q));
480 if (test_bit(flag, &q->queue_flags)) {
481 __clear_bit(flag, &q->queue_flags);
488 static inline int queue_flag_test_and_set(unsigned int flag,
489 struct request_queue *q)
491 WARN_ON_ONCE(!queue_is_locked(q));
493 if (!test_bit(flag, &q->queue_flags)) {
494 __set_bit(flag, &q->queue_flags);
501 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
503 WARN_ON_ONCE(!queue_is_locked(q));
504 __set_bit(flag, &q->queue_flags);
507 static inline void queue_flag_clear_unlocked(unsigned int flag,
508 struct request_queue *q)
510 __clear_bit(flag, &q->queue_flags);
513 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
515 WARN_ON_ONCE(!queue_is_locked(q));
516 __clear_bit(flag, &q->queue_flags);
521 * Hardbarrier is supported with one of the following methods.
523 * NONE : hardbarrier unsupported
524 * DRAIN : ordering by draining is enough
525 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
526 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
527 * TAG : ordering by tag is enough
528 * TAG_FLUSH : ordering by tag w/ pre and post flushes
529 * TAG_FUA : ordering by tag w/ pre flush and FUA write
531 QUEUE_ORDERED_BY_DRAIN = 0x01,
532 QUEUE_ORDERED_BY_TAG = 0x02,
533 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
534 QUEUE_ORDERED_DO_BAR = 0x20,
535 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
536 QUEUE_ORDERED_DO_FUA = 0x80,
538 QUEUE_ORDERED_NONE = 0x00,
540 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
541 QUEUE_ORDERED_DO_BAR,
542 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
543 QUEUE_ORDERED_DO_PREFLUSH |
544 QUEUE_ORDERED_DO_POSTFLUSH,
545 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
546 QUEUE_ORDERED_DO_PREFLUSH |
547 QUEUE_ORDERED_DO_FUA,
549 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
550 QUEUE_ORDERED_DO_BAR,
551 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
552 QUEUE_ORDERED_DO_PREFLUSH |
553 QUEUE_ORDERED_DO_POSTFLUSH,
554 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
555 QUEUE_ORDERED_DO_PREFLUSH |
556 QUEUE_ORDERED_DO_FUA,
559 * Ordered operation sequence
561 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
562 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
563 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
564 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
565 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
566 QUEUE_ORDSEQ_DONE = 0x20,
569 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
570 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
571 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
572 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
573 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
574 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
575 #define blk_queue_flushing(q) ((q)->ordseq)
576 #define blk_queue_stackable(q) \
577 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
579 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
580 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
581 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
582 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
584 #define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
585 #define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
586 #define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
587 #define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
588 blk_failfast_transport(rq) || \
589 blk_failfast_driver(rq))
590 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
591 #define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
593 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
595 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
596 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
597 #define blk_pm_request(rq) \
598 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
600 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
601 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
602 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
603 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
604 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
605 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
606 /* rq->queuelist of dequeued request must be list_empty() */
607 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
609 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
611 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
614 * We regard a request as sync, if either a read or a sync write
616 static inline bool rw_is_sync(unsigned int rw_flags)
618 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
621 static inline bool rq_is_sync(struct request *rq)
623 return rw_is_sync(rq->cmd_flags);
626 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
627 #define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
629 static inline int blk_queue_full(struct request_queue *q, int sync)
632 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
633 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
636 static inline void blk_set_queue_full(struct request_queue *q, int sync)
639 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
641 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
644 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
647 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
649 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
654 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
655 * it already be started by driver.
657 #define RQ_NOMERGE_FLAGS \
658 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
659 #define rq_mergeable(rq) \
660 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
661 (blk_discard_rq(rq) || blk_fs_request((rq))))
664 * q->prep_rq_fn return values
666 #define BLKPREP_OK 0 /* serve it */
667 #define BLKPREP_KILL 1 /* fatal error, kill */
668 #define BLKPREP_DEFER 2 /* leave on queue */
670 extern unsigned long blk_max_low_pfn, blk_max_pfn;
673 * standard bounce addresses:
675 * BLK_BOUNCE_HIGH : bounce all highmem pages
676 * BLK_BOUNCE_ANY : don't bounce anything
677 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
680 #if BITS_PER_LONG == 32
681 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
683 #define BLK_BOUNCE_HIGH -1ULL
685 #define BLK_BOUNCE_ANY (-1ULL)
686 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
689 * default timeout for SG_IO if none specified
691 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
692 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
695 extern int init_emergency_isa_pool(void);
696 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
698 static inline int init_emergency_isa_pool(void)
702 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
705 #endif /* CONFIG_MMU */
711 unsigned long offset;
715 struct req_iterator {
720 /* This should not be used directly - use rq_for_each_segment */
721 #define for_each_bio(_bio) \
722 for (; _bio; _bio = _bio->bi_next)
723 #define __rq_for_each_bio(_bio, rq) \
725 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
727 #define rq_for_each_segment(bvl, _rq, _iter) \
728 __rq_for_each_bio(_iter.bio, _rq) \
729 bio_for_each_segment(bvl, _iter.bio, _iter.i)
731 #define rq_iter_last(rq, _iter) \
732 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
734 extern int blk_register_queue(struct gendisk *disk);
735 extern void blk_unregister_queue(struct gendisk *disk);
736 extern void register_disk(struct gendisk *dev);
737 extern void generic_make_request(struct bio *bio);
738 extern void blk_rq_init(struct request_queue *q, struct request *rq);
739 extern void blk_put_request(struct request *);
740 extern void __blk_put_request(struct request_queue *, struct request *);
741 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
742 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
743 extern void blk_requeue_request(struct request_queue *, struct request *);
744 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
745 extern int blk_lld_busy(struct request_queue *q);
746 extern int blk_insert_cloned_request(struct request_queue *q,
748 extern void blk_plug_device(struct request_queue *);
749 extern void blk_plug_device_unlocked(struct request_queue *);
750 extern int blk_remove_plug(struct request_queue *);
751 extern void blk_recount_segments(struct request_queue *, struct bio *);
752 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
753 unsigned int, void __user *);
754 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
755 struct scsi_ioctl_command __user *);
758 * Temporary export, until SCSI gets fixed up.
760 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq,
764 * A queue has just exitted congestion. Note this in the global counter of
765 * congested queues, and wake up anyone who was waiting for requests to be
768 static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
770 clear_bdi_congested(&q->backing_dev_info, rw);
774 * A queue has just entered congestion. Flag that in the queue's VM-visible
775 * state flags and increment the global gounter of congested queues.
777 static inline void blk_set_queue_congested(struct request_queue *q, int rw)
779 set_bdi_congested(&q->backing_dev_info, rw);
782 extern void blk_start_queue(struct request_queue *q);
783 extern void blk_stop_queue(struct request_queue *q);
784 extern void blk_sync_queue(struct request_queue *q);
785 extern void __blk_stop_queue(struct request_queue *q);
786 extern void __blk_run_queue(struct request_queue *);
787 extern void blk_run_queue(struct request_queue *);
788 extern int blk_rq_map_user(struct request_queue *, struct request *,
789 struct rq_map_data *, void __user *, unsigned long,
791 extern int blk_rq_unmap_user(struct bio *);
792 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
793 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
794 struct rq_map_data *, struct sg_iovec *, int,
795 unsigned int, gfp_t);
796 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
797 struct request *, int);
798 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
799 struct request *, int, rq_end_io_fn *);
800 extern void blk_unplug(struct request_queue *q);
802 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
804 return bdev->bd_disk->queue;
807 static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
810 if (bdi && bdi->unplug_io_fn)
811 bdi->unplug_io_fn(bdi, page);
814 static inline void blk_run_address_space(struct address_space *mapping)
817 blk_run_backing_dev(mapping->backing_dev_info, NULL);
820 extern void blkdev_dequeue_request(struct request *req);
823 * blk_rq_pos() : the current sector
824 * blk_rq_bytes() : bytes left in the entire request
825 * blk_rq_cur_bytes() : bytes left in the current segment
826 * blk_rq_sectors() : sectors left in the entire request
827 * blk_rq_cur_sectors() : sectors left in the current segment
829 static inline sector_t blk_rq_pos(const struct request *rq)
834 static inline unsigned int blk_rq_bytes(const struct request *rq)
839 static inline int blk_rq_cur_bytes(const struct request *rq)
841 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
844 static inline unsigned int blk_rq_sectors(const struct request *rq)
846 return blk_rq_bytes(rq) >> 9;
849 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
851 return blk_rq_cur_bytes(rq) >> 9;
855 * Request completion related functions.
857 * blk_update_request() completes given number of bytes and updates
858 * the request without completing it.
860 * blk_end_request() and friends. __blk_end_request() must be called
861 * with the request queue spinlock acquired.
863 * Several drivers define their own end_request and call
864 * blk_end_request() for parts of the original function.
865 * This prevents code duplication in drivers.
867 extern bool blk_update_request(struct request *rq, int error,
868 unsigned int nr_bytes);
869 extern bool blk_end_bidi_request(struct request *rq, int error,
870 unsigned int nr_bytes,
871 unsigned int bidi_bytes);
872 extern bool __blk_end_bidi_request(struct request *rq, int error,
873 unsigned int nr_bytes,
874 unsigned int bidi_bytes);
877 * blk_end_request - Helper function for drivers to complete the request.
878 * @rq: the request being processed
879 * @error: %0 for success, < %0 for error
880 * @nr_bytes: number of bytes to complete
883 * Ends I/O on a number of bytes attached to @rq.
884 * If @rq has leftover, sets it up for the next range of segments.
887 * %false - we are done with this request
888 * %true - still buffers pending for this request
890 static inline bool blk_end_request(struct request *rq, int error,
891 unsigned int nr_bytes)
893 return blk_end_bidi_request(rq, error, nr_bytes, 0);
897 * blk_end_request_all - Helper function for drives to finish the request.
898 * @rq: the request to finish
899 * @err: %0 for success, < %0 for error
902 * Completely finish @rq.
904 static inline void blk_end_request_all(struct request *rq, int error)
908 pending = blk_end_request(rq, error, blk_rq_bytes(rq));
913 * blk_end_request_cur - Helper function to finish the current request chunk.
914 * @rq: the request to finish the current chunk for
915 * @err: %0 for success, < %0 for error
918 * Complete the current consecutively mapped chunk from @rq.
921 * %false - we are done with this request
922 * %true - still buffers pending for this request
924 static inline bool blk_end_request_cur(struct request *rq, int error)
926 return blk_end_request(rq, error, blk_rq_cur_bytes(rq));
930 * __blk_end_request - Helper function for drivers to complete the request.
931 * @rq: the request being processed
932 * @error: %0 for success, < %0 for error
933 * @nr_bytes: number of bytes to complete
936 * Must be called with queue lock held unlike blk_end_request().
939 * %false - we are done with this request
940 * %true - still buffers pending for this request
942 static inline bool __blk_end_request(struct request *rq, int error,
943 unsigned int nr_bytes)
945 return __blk_end_bidi_request(rq, error, nr_bytes, 0);
949 * __blk_end_request_all - Helper function for drives to finish the request.
950 * @rq: the request to finish
951 * @err: %0 for success, < %0 for error
954 * Completely finish @rq. Must be called with queue lock held.
956 static inline void __blk_end_request_all(struct request *rq, int error)
960 pending = __blk_end_request(rq, error, blk_rq_bytes(rq));
965 * __blk_end_request_cur - Helper function to finish the current request chunk.
966 * @rq: the request to finish the current chunk for
967 * @err: %0 for success, < %0 for error
970 * Complete the current consecutively mapped chunk from @rq. Must
971 * be called with queue lock held.
974 * %false - we are done with this request
975 * %true - still buffers pending for this request
977 static inline bool __blk_end_request_cur(struct request *rq, int error)
979 return __blk_end_request(rq, error, blk_rq_cur_bytes(rq));
982 extern void blk_complete_request(struct request *);
983 extern void __blk_complete_request(struct request *);
984 extern void blk_abort_request(struct request *);
985 extern void blk_abort_queue(struct request_queue *);
988 * Access functions for manipulating queue properties
990 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
991 spinlock_t *lock, int node_id);
992 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
993 extern void blk_cleanup_queue(struct request_queue *);
994 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
995 extern void blk_queue_bounce_limit(struct request_queue *, u64);
996 extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
997 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
998 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
999 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
1000 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
1001 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
1002 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
1003 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
1004 extern int blk_queue_dma_drain(struct request_queue *q,
1005 dma_drain_needed_fn *dma_drain_needed,
1006 void *buf, unsigned int size);
1007 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
1008 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
1009 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
1010 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
1011 extern void blk_queue_dma_alignment(struct request_queue *, int);
1012 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
1013 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
1014 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
1015 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
1016 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
1017 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1018 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
1019 extern bool blk_do_ordered(struct request_queue *, struct request **);
1020 extern unsigned blk_ordered_cur_seq(struct request_queue *);
1021 extern unsigned blk_ordered_req_seq(struct request *);
1022 extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
1024 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1025 extern void blk_dump_rq_flags(struct request *, char *);
1026 extern void generic_unplug_device(struct request_queue *);
1027 extern long nr_blockdev_pages(void);
1029 int blk_get_queue(struct request_queue *);
1030 struct request_queue *blk_alloc_queue(gfp_t);
1031 struct request_queue *blk_alloc_queue_node(gfp_t, int);
1032 extern void blk_put_queue(struct request_queue *);
1037 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
1038 extern int blk_queue_start_tag(struct request_queue *, struct request *);
1039 extern struct request *blk_queue_find_tag(struct request_queue *, int);
1040 extern void blk_queue_end_tag(struct request_queue *, struct request *);
1041 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
1042 extern void blk_queue_free_tags(struct request_queue *);
1043 extern int blk_queue_resize_tags(struct request_queue *, int);
1044 extern void blk_queue_invalidate_tags(struct request_queue *);
1045 extern struct blk_queue_tag *blk_init_tags(int);
1046 extern void blk_free_tags(struct blk_queue_tag *);
1048 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
1051 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
1053 return bqt->tag_index[tag];
1056 extern int blkdev_issue_flush(struct block_device *, sector_t *);
1057 extern int blkdev_issue_discard(struct block_device *,
1058 sector_t sector, sector_t nr_sects, gfp_t);
1060 static inline int sb_issue_discard(struct super_block *sb,
1061 sector_t block, sector_t nr_blocks)
1063 block <<= (sb->s_blocksize_bits - 9);
1064 nr_blocks <<= (sb->s_blocksize_bits - 9);
1065 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
1069 * command filter functions
1071 extern int blk_verify_command(struct blk_cmd_filter *filter,
1072 unsigned char *cmd, fmode_t has_write_perm);
1073 extern void blk_unregister_filter(struct gendisk *disk);
1074 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
1076 #define MAX_PHYS_SEGMENTS 128
1077 #define MAX_HW_SEGMENTS 128
1078 #define SAFE_MAX_SECTORS 255
1079 #define BLK_DEF_MAX_SECTORS 1024
1081 #define MAX_SEGMENT_SIZE 65536
1083 #define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
1085 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
1087 static inline int queue_hardsect_size(struct request_queue *q)
1091 if (q && q->hardsect_size)
1092 retval = q->hardsect_size;
1097 static inline int bdev_hardsect_size(struct block_device *bdev)
1099 return queue_hardsect_size(bdev_get_queue(bdev));
1102 static inline int queue_dma_alignment(struct request_queue *q)
1104 return q ? q->dma_alignment : 511;
1107 static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1110 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1111 return !((unsigned long)addr & alignment) && !(len & alignment);
1114 /* assumes size > 256 */
1115 static inline unsigned int blksize_bits(unsigned int size)
1117 unsigned int bits = 8;
1121 } while (size > 256);
1125 static inline unsigned int block_size(struct block_device *bdev)
1127 return bdev->bd_block_size;
1130 typedef struct {struct page *v;} Sector;
1132 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1134 static inline void put_dev_sector(Sector p)
1136 page_cache_release(p.v);
1140 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1142 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1143 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1144 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1145 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1147 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1149 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1150 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1152 struct blk_integrity_exchg {
1156 unsigned int data_size;
1157 unsigned short sector_size;
1158 const char *disk_name;
1161 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1162 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1163 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1164 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1166 struct blk_integrity {
1167 integrity_gen_fn *generate_fn;
1168 integrity_vrfy_fn *verify_fn;
1169 integrity_set_tag_fn *set_tag_fn;
1170 integrity_get_tag_fn *get_tag_fn;
1172 unsigned short flags;
1173 unsigned short tuple_size;
1174 unsigned short sector_size;
1175 unsigned short tag_size;
1179 struct kobject kobj;
1182 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1183 extern void blk_integrity_unregister(struct gendisk *);
1184 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1185 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1186 extern int blk_rq_count_integrity_sg(struct request *);
1189 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1191 return bdev->bd_disk->integrity;
1194 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1196 return disk->integrity;
1199 static inline int blk_integrity_rq(struct request *rq)
1201 if (rq->bio == NULL)
1204 return bio_integrity(rq->bio);
1207 #else /* CONFIG_BLK_DEV_INTEGRITY */
1209 #define blk_integrity_rq(rq) (0)
1210 #define blk_rq_count_integrity_sg(a) (0)
1211 #define blk_rq_map_integrity_sg(a, b) (0)
1212 #define bdev_get_integrity(a) (0)
1213 #define blk_get_integrity(a) (0)
1214 #define blk_integrity_compare(a, b) (0)
1215 #define blk_integrity_register(a, b) (0)
1216 #define blk_integrity_unregister(a) do { } while (0);
1218 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1220 struct block_device_operations {
1221 int (*open) (struct block_device *, fmode_t);
1222 int (*release) (struct gendisk *, fmode_t);
1223 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1224 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1225 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1226 int (*direct_access) (struct block_device *, sector_t,
1227 void **, unsigned long *);
1228 int (*media_changed) (struct gendisk *);
1229 int (*revalidate_disk) (struct gendisk *);
1230 int (*getgeo)(struct block_device *, struct hd_geometry *);
1231 struct module *owner;
1234 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1236 #else /* CONFIG_BLOCK */
1238 * stubs for when the block layer is configured out
1240 #define buffer_heads_over_limit 0
1242 static inline long nr_blockdev_pages(void)
1247 #endif /* CONFIG_BLOCK */