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 /* the following two fields are internal, NEVER access directly */
170 sector_t __sector; /* sector cursor */
171 unsigned int __data_len; /* total data len */
176 struct hlist_node hash; /* merge hash */
178 * The rb_node is only used inside the io scheduler, requests
179 * are pruned when moved to the dispatch queue. So let the
180 * completion_data share space with the rb_node.
183 struct rb_node rb_node; /* sort/lookup */
184 void *completion_data;
188 * two pointers are available for the IO schedulers, if they need
189 * more they have to dynamically allocate it.
191 void *elevator_private;
192 void *elevator_private2;
194 struct gendisk *rq_disk;
195 unsigned long start_time;
197 /* Number of scatter-gather DMA addr+len pairs after
198 * physical address coalescing is performed.
200 unsigned short nr_phys_segments;
202 unsigned short ioprio;
204 void *special; /* opaque pointer available for LLD use */
205 char *buffer; /* kaddr of the current segment if available */
213 * when request is used as a packet command carrier
215 unsigned short cmd_len;
216 unsigned char __cmd[BLK_MAX_CDB];
219 unsigned int extra_len; /* length of alignment and padding */
220 unsigned int sense_len;
221 unsigned int resid_len; /* residual count */
224 unsigned long deadline;
225 struct list_head timeout_list;
226 unsigned int timeout;
230 * completion callback.
232 rq_end_io_fn *end_io;
236 struct request *next_rq;
239 static inline unsigned short req_get_ioprio(struct request *req)
245 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
246 * requests. Some step values could eventually be made generic.
248 struct request_pm_state
250 /* PM state machine step value, currently driver specific */
252 /* requested PM state value (S1, S2, S3, S4, ...) */
254 void* data; /* for driver use */
257 #include <linux/elevator.h>
259 typedef void (request_fn_proc) (struct request_queue *q);
260 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
261 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
262 typedef void (unplug_fn) (struct request_queue *);
263 typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
266 struct bvec_merge_data {
267 struct block_device *bi_bdev;
272 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
274 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
275 typedef void (softirq_done_fn)(struct request *);
276 typedef int (dma_drain_needed_fn)(struct request *);
277 typedef int (lld_busy_fn) (struct request_queue *q);
279 enum blk_eh_timer_return {
285 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
287 enum blk_queue_state {
292 struct blk_queue_tag {
293 struct request **tag_index; /* map of busy tags */
294 unsigned long *tag_map; /* bit map of free/busy tags */
295 int busy; /* current depth */
296 int max_depth; /* what we will send to device */
297 int real_max_depth; /* what the array can hold */
298 atomic_t refcnt; /* map can be shared */
301 #define BLK_SCSI_MAX_CMDS (256)
302 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
304 struct blk_cmd_filter {
305 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
306 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
313 * Together with queue_head for cacheline sharing
315 struct list_head queue_head;
316 struct request *last_merge;
317 struct elevator_queue *elevator;
320 * the queue request freelist, one for reads and one for writes
322 struct request_list rq;
324 request_fn_proc *request_fn;
325 make_request_fn *make_request_fn;
326 prep_rq_fn *prep_rq_fn;
327 unplug_fn *unplug_fn;
328 prepare_discard_fn *prepare_discard_fn;
329 merge_bvec_fn *merge_bvec_fn;
330 prepare_flush_fn *prepare_flush_fn;
331 softirq_done_fn *softirq_done_fn;
332 rq_timed_out_fn *rq_timed_out_fn;
333 dma_drain_needed_fn *dma_drain_needed;
334 lld_busy_fn *lld_busy_fn;
337 * Dispatch queue sorting
340 struct request *boundary_rq;
343 * Auto-unplugging state
345 struct timer_list unplug_timer;
346 int unplug_thresh; /* After this many requests */
347 unsigned long unplug_delay; /* After this many jiffies */
348 struct work_struct unplug_work;
350 struct backing_dev_info backing_dev_info;
353 * The queue owner gets to use this for whatever they like.
354 * ll_rw_blk doesn't touch it.
359 * queue needs bounce pages for pages above this limit
361 unsigned long bounce_pfn;
365 * various queue flags, see QUEUE_* below
367 unsigned long queue_flags;
370 * protects queue structures from reentrancy. ->__queue_lock should
371 * _never_ be used directly, it is queue private. always use
374 spinlock_t __queue_lock;
375 spinlock_t *queue_lock;
385 unsigned long nr_requests; /* Max # of requests */
386 unsigned int nr_congestion_on;
387 unsigned int nr_congestion_off;
388 unsigned int nr_batching;
390 unsigned int max_sectors;
391 unsigned int max_hw_sectors;
392 unsigned short max_phys_segments;
393 unsigned short max_hw_segments;
394 unsigned short hardsect_size;
395 unsigned int max_segment_size;
397 unsigned long seg_boundary_mask;
398 void *dma_drain_buffer;
399 unsigned int dma_drain_size;
400 unsigned int dma_pad_mask;
401 unsigned int dma_alignment;
403 struct blk_queue_tag *queue_tags;
404 struct list_head tag_busy_list;
406 unsigned int nr_sorted;
407 unsigned int in_flight;
409 unsigned int rq_timeout;
410 struct timer_list timeout;
411 struct list_head timeout_list;
416 unsigned int sg_timeout;
417 unsigned int sg_reserved_size;
419 #ifdef CONFIG_BLK_DEV_IO_TRACE
420 struct blk_trace *blk_trace;
423 * reserved for flush operations
425 unsigned int ordered, next_ordered, ordseq;
426 int orderr, ordcolor;
427 struct request pre_flush_rq, bar_rq, post_flush_rq;
428 struct request *orig_bar_rq;
430 struct mutex sysfs_lock;
432 #if defined(CONFIG_BLK_DEV_BSG)
433 struct bsg_class_device bsg_dev;
435 struct blk_cmd_filter cmd_filter;
438 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
439 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
440 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
441 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
442 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
443 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */
444 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
445 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
446 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
447 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
448 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */
449 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */
450 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
451 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
452 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
453 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
454 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */
456 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
457 (1 << QUEUE_FLAG_CLUSTER) | \
458 (1 << QUEUE_FLAG_STACKABLE))
460 static inline int queue_is_locked(struct request_queue *q)
463 spinlock_t *lock = q->queue_lock;
464 return lock && spin_is_locked(lock);
470 static inline void queue_flag_set_unlocked(unsigned int flag,
471 struct request_queue *q)
473 __set_bit(flag, &q->queue_flags);
476 static inline int queue_flag_test_and_clear(unsigned int flag,
477 struct request_queue *q)
479 WARN_ON_ONCE(!queue_is_locked(q));
481 if (test_bit(flag, &q->queue_flags)) {
482 __clear_bit(flag, &q->queue_flags);
489 static inline int queue_flag_test_and_set(unsigned int flag,
490 struct request_queue *q)
492 WARN_ON_ONCE(!queue_is_locked(q));
494 if (!test_bit(flag, &q->queue_flags)) {
495 __set_bit(flag, &q->queue_flags);
502 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
504 WARN_ON_ONCE(!queue_is_locked(q));
505 __set_bit(flag, &q->queue_flags);
508 static inline void queue_flag_clear_unlocked(unsigned int flag,
509 struct request_queue *q)
511 __clear_bit(flag, &q->queue_flags);
514 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
516 WARN_ON_ONCE(!queue_is_locked(q));
517 __clear_bit(flag, &q->queue_flags);
522 * Hardbarrier is supported with one of the following methods.
524 * NONE : hardbarrier unsupported
525 * DRAIN : ordering by draining is enough
526 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
527 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
528 * TAG : ordering by tag is enough
529 * TAG_FLUSH : ordering by tag w/ pre and post flushes
530 * TAG_FUA : ordering by tag w/ pre flush and FUA write
532 QUEUE_ORDERED_BY_DRAIN = 0x01,
533 QUEUE_ORDERED_BY_TAG = 0x02,
534 QUEUE_ORDERED_DO_PREFLUSH = 0x10,
535 QUEUE_ORDERED_DO_BAR = 0x20,
536 QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
537 QUEUE_ORDERED_DO_FUA = 0x80,
539 QUEUE_ORDERED_NONE = 0x00,
541 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
542 QUEUE_ORDERED_DO_BAR,
543 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
544 QUEUE_ORDERED_DO_PREFLUSH |
545 QUEUE_ORDERED_DO_POSTFLUSH,
546 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
547 QUEUE_ORDERED_DO_PREFLUSH |
548 QUEUE_ORDERED_DO_FUA,
550 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
551 QUEUE_ORDERED_DO_BAR,
552 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
553 QUEUE_ORDERED_DO_PREFLUSH |
554 QUEUE_ORDERED_DO_POSTFLUSH,
555 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
556 QUEUE_ORDERED_DO_PREFLUSH |
557 QUEUE_ORDERED_DO_FUA,
560 * Ordered operation sequence
562 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
563 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
564 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
565 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
566 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
567 QUEUE_ORDSEQ_DONE = 0x20,
570 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
571 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
572 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
573 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
574 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
575 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
576 #define blk_queue_flushing(q) ((q)->ordseq)
577 #define blk_queue_stackable(q) \
578 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
580 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
581 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
582 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL)
583 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE)
585 #define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV)
586 #define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT)
587 #define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER)
588 #define blk_noretry_request(rq) (blk_failfast_dev(rq) || \
589 blk_failfast_transport(rq) || \
590 blk_failfast_driver(rq))
591 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED)
592 #define blk_rq_io_stat(rq) ((rq)->cmd_flags & REQ_IO_STAT)
594 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))
596 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
597 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME)
598 #define blk_pm_request(rq) \
599 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
601 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
602 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
603 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
604 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
605 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
606 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
607 /* rq->queuelist of dequeued request must be list_empty() */
608 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
610 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
612 #define rq_data_dir(rq) ((rq)->cmd_flags & 1)
615 * We regard a request as sync, if either a read or a sync write
617 static inline bool rw_is_sync(unsigned int rw_flags)
619 return !(rw_flags & REQ_RW) || (rw_flags & REQ_RW_SYNC);
622 static inline bool rq_is_sync(struct request *rq)
624 return rw_is_sync(rq->cmd_flags);
627 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META)
628 #define rq_noidle(rq) ((rq)->cmd_flags & REQ_NOIDLE)
630 static inline int blk_queue_full(struct request_queue *q, int sync)
633 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
634 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
637 static inline void blk_set_queue_full(struct request_queue *q, int sync)
640 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
642 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
645 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
648 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
650 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
655 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
656 * it already be started by driver.
658 #define RQ_NOMERGE_FLAGS \
659 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
660 #define rq_mergeable(rq) \
661 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
662 (blk_discard_rq(rq) || blk_fs_request((rq))))
665 * q->prep_rq_fn return values
667 #define BLKPREP_OK 0 /* serve it */
668 #define BLKPREP_KILL 1 /* fatal error, kill */
669 #define BLKPREP_DEFER 2 /* leave on queue */
671 extern unsigned long blk_max_low_pfn, blk_max_pfn;
674 * standard bounce addresses:
676 * BLK_BOUNCE_HIGH : bounce all highmem pages
677 * BLK_BOUNCE_ANY : don't bounce anything
678 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
681 #if BITS_PER_LONG == 32
682 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
684 #define BLK_BOUNCE_HIGH -1ULL
686 #define BLK_BOUNCE_ANY (-1ULL)
687 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
690 * default timeout for SG_IO if none specified
692 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
693 #define BLK_MIN_SG_TIMEOUT (7 * HZ)
696 extern int init_emergency_isa_pool(void);
697 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
699 static inline int init_emergency_isa_pool(void)
703 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
706 #endif /* CONFIG_MMU */
712 unsigned long offset;
716 struct req_iterator {
721 /* This should not be used directly - use rq_for_each_segment */
722 #define for_each_bio(_bio) \
723 for (; _bio; _bio = _bio->bi_next)
724 #define __rq_for_each_bio(_bio, rq) \
726 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
728 #define rq_for_each_segment(bvl, _rq, _iter) \
729 __rq_for_each_bio(_iter.bio, _rq) \
730 bio_for_each_segment(bvl, _iter.bio, _iter.i)
732 #define rq_iter_last(rq, _iter) \
733 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
735 extern int blk_register_queue(struct gendisk *disk);
736 extern void blk_unregister_queue(struct gendisk *disk);
737 extern void register_disk(struct gendisk *dev);
738 extern void generic_make_request(struct bio *bio);
739 extern void blk_rq_init(struct request_queue *q, struct request *rq);
740 extern void blk_put_request(struct request *);
741 extern void __blk_put_request(struct request_queue *, struct request *);
742 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
743 extern struct request *blk_make_request(struct request_queue *, struct bio *,
745 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
746 extern void blk_requeue_request(struct request_queue *, struct request *);
747 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
748 extern int blk_lld_busy(struct request_queue *q);
749 extern int blk_insert_cloned_request(struct request_queue *q,
751 extern void blk_plug_device(struct request_queue *);
752 extern void blk_plug_device_unlocked(struct request_queue *);
753 extern int blk_remove_plug(struct request_queue *);
754 extern void blk_recount_segments(struct request_queue *, struct bio *);
755 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
756 unsigned int, void __user *);
757 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
758 struct scsi_ioctl_command __user *);
761 * A queue has just exitted congestion. Note this in the global counter of
762 * congested queues, and wake up anyone who was waiting for requests to be
765 static inline void blk_clear_queue_congested(struct request_queue *q, int rw)
767 clear_bdi_congested(&q->backing_dev_info, rw);
771 * A queue has just entered congestion. Flag that in the queue's VM-visible
772 * state flags and increment the global gounter of congested queues.
774 static inline void blk_set_queue_congested(struct request_queue *q, int rw)
776 set_bdi_congested(&q->backing_dev_info, rw);
779 extern void blk_start_queue(struct request_queue *q);
780 extern void blk_stop_queue(struct request_queue *q);
781 extern void blk_sync_queue(struct request_queue *q);
782 extern void __blk_stop_queue(struct request_queue *q);
783 extern void __blk_run_queue(struct request_queue *);
784 extern void blk_run_queue(struct request_queue *);
785 extern int blk_rq_map_user(struct request_queue *, struct request *,
786 struct rq_map_data *, void __user *, unsigned long,
788 extern int blk_rq_unmap_user(struct bio *);
789 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
790 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
791 struct rq_map_data *, struct sg_iovec *, int,
792 unsigned int, gfp_t);
793 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
794 struct request *, int);
795 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
796 struct request *, int, rq_end_io_fn *);
797 extern void blk_unplug(struct request_queue *q);
799 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
801 return bdev->bd_disk->queue;
804 static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
807 if (bdi && bdi->unplug_io_fn)
808 bdi->unplug_io_fn(bdi, page);
811 static inline void blk_run_address_space(struct address_space *mapping)
814 blk_run_backing_dev(mapping->backing_dev_info, NULL);
818 * blk_rq_pos() : the current sector
819 * blk_rq_bytes() : bytes left in the entire request
820 * blk_rq_cur_bytes() : bytes left in the current segment
821 * blk_rq_sectors() : sectors left in the entire request
822 * blk_rq_cur_sectors() : sectors left in the current segment
824 static inline sector_t blk_rq_pos(const struct request *rq)
829 static inline unsigned int blk_rq_bytes(const struct request *rq)
831 return rq->__data_len;
834 static inline int blk_rq_cur_bytes(const struct request *rq)
836 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
839 static inline unsigned int blk_rq_sectors(const struct request *rq)
841 return blk_rq_bytes(rq) >> 9;
844 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
846 return blk_rq_cur_bytes(rq) >> 9;
850 * Request issue related functions.
852 extern struct request *blk_peek_request(struct request_queue *q);
853 extern void blk_start_request(struct request *rq);
854 extern struct request *blk_fetch_request(struct request_queue *q);
857 * Request completion related functions.
859 * blk_update_request() completes given number of bytes and updates
860 * the request without completing it.
862 * blk_end_request() and friends. __blk_end_request() must be called
863 * with the request queue spinlock acquired.
865 * Several drivers define their own end_request and call
866 * blk_end_request() for parts of the original function.
867 * This prevents code duplication in drivers.
869 extern bool blk_update_request(struct request *rq, int error,
870 unsigned int nr_bytes);
871 extern bool blk_end_request(struct request *rq, int error,
872 unsigned int nr_bytes);
873 extern void blk_end_request_all(struct request *rq, int error);
874 extern bool blk_end_request_cur(struct request *rq, int error);
875 extern bool __blk_end_request(struct request *rq, int error,
876 unsigned int nr_bytes);
877 extern void __blk_end_request_all(struct request *rq, int error);
878 extern bool __blk_end_request_cur(struct request *rq, int error);
880 extern void blk_complete_request(struct request *);
881 extern void __blk_complete_request(struct request *);
882 extern void blk_abort_request(struct request *);
883 extern void blk_abort_queue(struct request_queue *);
886 * Access functions for manipulating queue properties
888 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
889 spinlock_t *lock, int node_id);
890 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
891 extern void blk_cleanup_queue(struct request_queue *);
892 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
893 extern void blk_queue_bounce_limit(struct request_queue *, u64);
894 extern void blk_queue_max_sectors(struct request_queue *, unsigned int);
895 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short);
896 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
897 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
898 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
899 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
900 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
901 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
902 extern int blk_queue_dma_drain(struct request_queue *q,
903 dma_drain_needed_fn *dma_drain_needed,
904 void *buf, unsigned int size);
905 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
906 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
907 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
908 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
909 extern void blk_queue_dma_alignment(struct request_queue *, int);
910 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
911 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
912 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
913 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
914 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
915 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
916 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
917 extern bool blk_do_ordered(struct request_queue *, struct request **);
918 extern unsigned blk_ordered_cur_seq(struct request_queue *);
919 extern unsigned blk_ordered_req_seq(struct request *);
920 extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
922 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
923 extern void blk_dump_rq_flags(struct request *, char *);
924 extern void generic_unplug_device(struct request_queue *);
925 extern long nr_blockdev_pages(void);
927 int blk_get_queue(struct request_queue *);
928 struct request_queue *blk_alloc_queue(gfp_t);
929 struct request_queue *blk_alloc_queue_node(gfp_t, int);
930 extern void blk_put_queue(struct request_queue *);
935 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
936 extern int blk_queue_start_tag(struct request_queue *, struct request *);
937 extern struct request *blk_queue_find_tag(struct request_queue *, int);
938 extern void blk_queue_end_tag(struct request_queue *, struct request *);
939 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
940 extern void blk_queue_free_tags(struct request_queue *);
941 extern int blk_queue_resize_tags(struct request_queue *, int);
942 extern void blk_queue_invalidate_tags(struct request_queue *);
943 extern struct blk_queue_tag *blk_init_tags(int);
944 extern void blk_free_tags(struct blk_queue_tag *);
946 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
949 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
951 return bqt->tag_index[tag];
954 extern int blkdev_issue_flush(struct block_device *, sector_t *);
955 extern int blkdev_issue_discard(struct block_device *,
956 sector_t sector, sector_t nr_sects, gfp_t);
958 static inline int sb_issue_discard(struct super_block *sb,
959 sector_t block, sector_t nr_blocks)
961 block <<= (sb->s_blocksize_bits - 9);
962 nr_blocks <<= (sb->s_blocksize_bits - 9);
963 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
967 * command filter functions
969 extern int blk_verify_command(struct blk_cmd_filter *filter,
970 unsigned char *cmd, fmode_t has_write_perm);
971 extern void blk_unregister_filter(struct gendisk *disk);
972 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
974 #define MAX_PHYS_SEGMENTS 128
975 #define MAX_HW_SEGMENTS 128
976 #define SAFE_MAX_SECTORS 255
977 #define BLK_DEF_MAX_SECTORS 1024
979 #define MAX_SEGMENT_SIZE 65536
981 #define BLK_SEG_BOUNDARY_MASK 0xFFFFFFFFUL
983 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
985 static inline int queue_hardsect_size(struct request_queue *q)
989 if (q && q->hardsect_size)
990 retval = q->hardsect_size;
995 static inline int bdev_hardsect_size(struct block_device *bdev)
997 return queue_hardsect_size(bdev_get_queue(bdev));
1000 static inline int queue_dma_alignment(struct request_queue *q)
1002 return q ? q->dma_alignment : 511;
1005 static inline int blk_rq_aligned(struct request_queue *q, void *addr,
1008 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1009 return !((unsigned long)addr & alignment) && !(len & alignment);
1012 /* assumes size > 256 */
1013 static inline unsigned int blksize_bits(unsigned int size)
1015 unsigned int bits = 8;
1019 } while (size > 256);
1023 static inline unsigned int block_size(struct block_device *bdev)
1025 return bdev->bd_block_size;
1028 typedef struct {struct page *v;} Sector;
1030 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1032 static inline void put_dev_sector(Sector p)
1034 page_cache_release(p.v);
1038 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1040 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1041 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1042 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1043 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1045 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1047 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1048 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
1050 struct blk_integrity_exchg {
1054 unsigned int data_size;
1055 unsigned short sector_size;
1056 const char *disk_name;
1059 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1060 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1061 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1062 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1064 struct blk_integrity {
1065 integrity_gen_fn *generate_fn;
1066 integrity_vrfy_fn *verify_fn;
1067 integrity_set_tag_fn *set_tag_fn;
1068 integrity_get_tag_fn *get_tag_fn;
1070 unsigned short flags;
1071 unsigned short tuple_size;
1072 unsigned short sector_size;
1073 unsigned short tag_size;
1077 struct kobject kobj;
1080 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1081 extern void blk_integrity_unregister(struct gendisk *);
1082 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1083 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
1084 extern int blk_rq_count_integrity_sg(struct request *);
1087 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1089 return bdev->bd_disk->integrity;
1092 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1094 return disk->integrity;
1097 static inline int blk_integrity_rq(struct request *rq)
1099 if (rq->bio == NULL)
1102 return bio_integrity(rq->bio);
1105 #else /* CONFIG_BLK_DEV_INTEGRITY */
1107 #define blk_integrity_rq(rq) (0)
1108 #define blk_rq_count_integrity_sg(a) (0)
1109 #define blk_rq_map_integrity_sg(a, b) (0)
1110 #define bdev_get_integrity(a) (0)
1111 #define blk_get_integrity(a) (0)
1112 #define blk_integrity_compare(a, b) (0)
1113 #define blk_integrity_register(a, b) (0)
1114 #define blk_integrity_unregister(a) do { } while (0);
1116 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1118 struct block_device_operations {
1119 int (*open) (struct block_device *, fmode_t);
1120 int (*release) (struct gendisk *, fmode_t);
1121 int (*locked_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1122 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1123 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1124 int (*direct_access) (struct block_device *, sector_t,
1125 void **, unsigned long *);
1126 int (*media_changed) (struct gendisk *);
1127 int (*revalidate_disk) (struct gendisk *);
1128 int (*getgeo)(struct block_device *, struct hd_geometry *);
1129 struct module *owner;
1132 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1134 #else /* CONFIG_BLOCK */
1136 * stubs for when the block layer is configured out
1138 #define buffer_heads_over_limit 0
1140 static inline long nr_blockdev_pages(void)
1145 #endif /* CONFIG_BLOCK */