kernel-ark/include/linux/blkdev.h
Jens Axboe 206dc69b31 [BLOCK] cfq-iosched: seek and async performance fixes
Detect whether a given process is seeky and if so disable (mostly) the
idle window if it is. We still allow just a little idle time, just enough
to allow that process to submit a new request. That is needed to maintain
fairness across priority groups.

In some cases, we could setup several async queues. This is not optimal
from a performance POV, since we want all async io in one queue to perform
good sorting on it. It also impacted sync queues, as async io got too much
slice time.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-03-28 13:03:44 +02:00

849 lines
25 KiB
C

#ifndef _LINUX_BLKDEV_H
#define _LINUX_BLKDEV_H
#include <linux/config.h>
#include <linux/major.h>
#include <linux/genhd.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/pagemap.h>
#include <linux/backing-dev.h>
#include <linux/wait.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/stringify.h>
#include <asm/scatterlist.h>
struct request_queue;
typedef struct request_queue request_queue_t;
struct elevator_queue;
typedef struct elevator_queue elevator_t;
struct request_pm_state;
struct blk_trace;
#define BLKDEV_MIN_RQ 4
#define BLKDEV_MAX_RQ 128 /* Default maximum */
/*
* This is the per-process anticipatory I/O scheduler state.
*/
struct as_io_context {
spinlock_t lock;
void (*dtor)(struct as_io_context *aic); /* destructor */
void (*exit)(struct as_io_context *aic); /* called on task exit */
unsigned long state;
atomic_t nr_queued; /* queued reads & sync writes */
atomic_t nr_dispatched; /* number of requests gone to the drivers */
/* IO History tracking */
/* Thinktime */
unsigned long last_end_request;
unsigned long ttime_total;
unsigned long ttime_samples;
unsigned long ttime_mean;
/* Layout pattern */
unsigned int seek_samples;
sector_t last_request_pos;
u64 seek_total;
sector_t seek_mean;
};
struct cfq_queue;
struct cfq_io_context {
struct rb_node rb_node;
void *key;
struct cfq_queue *cfqq[2];
struct io_context *ioc;
unsigned long last_end_request;
sector_t last_request_pos;
unsigned long last_queue;
unsigned long ttime_total;
unsigned long ttime_samples;
unsigned long ttime_mean;
unsigned int seek_samples;
u64 seek_total;
sector_t seek_mean;
struct list_head queue_list;
void (*dtor)(struct io_context *); /* destructor */
void (*exit)(struct io_context *); /* called on task exit */
};
/*
* This is the per-process I/O subsystem state. It is refcounted and
* kmalloc'ed. Currently all fields are modified in process io context
* (apart from the atomic refcount), so require no locking.
*/
struct io_context {
atomic_t refcount;
struct task_struct *task;
int (*set_ioprio)(struct io_context *, unsigned int);
/*
* For request batching
*/
unsigned long last_waited; /* Time last woken after wait for request */
int nr_batch_requests; /* Number of requests left in the batch */
struct as_io_context *aic;
struct rb_root cic_root;
};
void put_io_context(struct io_context *ioc);
void exit_io_context(void);
struct io_context *current_io_context(gfp_t gfp_flags);
struct io_context *get_io_context(gfp_t gfp_flags);
void copy_io_context(struct io_context **pdst, struct io_context **psrc);
void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
struct request;
typedef void (rq_end_io_fn)(struct request *, int);
struct request_list {
int count[2];
int starved[2];
int elvpriv;
mempool_t *rq_pool;
wait_queue_head_t wait[2];
};
#define BLK_MAX_CDB 16
/*
* try to put the fields that are referenced together in the same cacheline
*/
struct request {
struct list_head queuelist;
struct list_head donelist;
unsigned long flags; /* see REQ_ bits below */
/* Maintain bio traversal state for part by part I/O submission.
* hard_* are block layer internals, no driver should touch them!
*/
sector_t sector; /* next sector to submit */
unsigned long nr_sectors; /* no. of sectors left to submit */
/* no. of sectors left to submit in the current segment */
unsigned int current_nr_sectors;
sector_t hard_sector; /* next sector to complete */
unsigned long hard_nr_sectors; /* no. of sectors left to complete */
/* no. of sectors left to complete in the current segment */
unsigned int hard_cur_sectors;
struct bio *bio;
struct bio *biotail;
void *elevator_private;
void *completion_data;
unsigned short ioprio;
int rq_status; /* should split this into a few status bits */
struct gendisk *rq_disk;
int errors;
unsigned long start_time;
/* Number of scatter-gather DMA addr+len pairs after
* physical address coalescing is performed.
*/
unsigned short nr_phys_segments;
/* Number of scatter-gather addr+len pairs after
* physical and DMA remapping hardware coalescing is performed.
* This is the number of scatter-gather entries the driver
* will actually have to deal with after DMA mapping is done.
*/
unsigned short nr_hw_segments;
int tag;
char *buffer;
int ref_count;
request_queue_t *q;
struct request_list *rl;
struct completion *waiting;
void *special;
/*
* when request is used as a packet command carrier
*/
unsigned int cmd_len;
unsigned char cmd[BLK_MAX_CDB];
unsigned int data_len;
void *data;
unsigned int sense_len;
void *sense;
unsigned int timeout;
int retries;
/*
* For Power Management requests
*/
struct request_pm_state *pm;
/*
* completion callback. end_io_data should be folded in with waiting
*/
rq_end_io_fn *end_io;
void *end_io_data;
};
/*
* first three bits match BIO_RW* bits, important
*/
enum rq_flag_bits {
__REQ_RW, /* not set, read. set, write */
__REQ_FAILFAST, /* no low level driver retries */
__REQ_SORTED, /* elevator knows about this request */
__REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
__REQ_HARDBARRIER, /* may not be passed by drive either */
__REQ_FUA, /* forced unit access */
__REQ_CMD, /* is a regular fs rw request */
__REQ_NOMERGE, /* don't touch this for merging */
__REQ_STARTED, /* drive already may have started this one */
__REQ_DONTPREP, /* don't call prep for this one */
__REQ_QUEUED, /* uses queueing */
__REQ_ELVPRIV, /* elevator private data attached */
/*
* for ATA/ATAPI devices
*/
__REQ_PC, /* packet command (special) */
__REQ_BLOCK_PC, /* queued down pc from block layer */
__REQ_SENSE, /* sense retrival */
__REQ_FAILED, /* set if the request failed */
__REQ_QUIET, /* don't worry about errors */
__REQ_SPECIAL, /* driver suplied command */
__REQ_DRIVE_CMD,
__REQ_DRIVE_TASK,
__REQ_DRIVE_TASKFILE,
__REQ_PREEMPT, /* set for "ide_preempt" requests */
__REQ_PM_SUSPEND, /* suspend request */
__REQ_PM_RESUME, /* resume request */
__REQ_PM_SHUTDOWN, /* shutdown request */
__REQ_ORDERED_COLOR, /* is before or after barrier */
__REQ_NR_BITS, /* stops here */
};
#define REQ_RW (1 << __REQ_RW)
#define REQ_FAILFAST (1 << __REQ_FAILFAST)
#define REQ_SORTED (1 << __REQ_SORTED)
#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
#define REQ_FUA (1 << __REQ_FUA)
#define REQ_CMD (1 << __REQ_CMD)
#define REQ_NOMERGE (1 << __REQ_NOMERGE)
#define REQ_STARTED (1 << __REQ_STARTED)
#define REQ_DONTPREP (1 << __REQ_DONTPREP)
#define REQ_QUEUED (1 << __REQ_QUEUED)
#define REQ_ELVPRIV (1 << __REQ_ELVPRIV)
#define REQ_PC (1 << __REQ_PC)
#define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC)
#define REQ_SENSE (1 << __REQ_SENSE)
#define REQ_FAILED (1 << __REQ_FAILED)
#define REQ_QUIET (1 << __REQ_QUIET)
#define REQ_SPECIAL (1 << __REQ_SPECIAL)
#define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD)
#define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK)
#define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE)
#define REQ_PREEMPT (1 << __REQ_PREEMPT)
#define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND)
#define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
/*
* State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
* requests. Some step values could eventually be made generic.
*/
struct request_pm_state
{
/* PM state machine step value, currently driver specific */
int pm_step;
/* requested PM state value (S1, S2, S3, S4, ...) */
u32 pm_state;
void* data; /* for driver use */
};
#include <linux/elevator.h>
typedef int (merge_request_fn) (request_queue_t *, struct request *,
struct bio *);
typedef int (merge_requests_fn) (request_queue_t *, struct request *,
struct request *);
typedef void (request_fn_proc) (request_queue_t *q);
typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
typedef int (prep_rq_fn) (request_queue_t *, struct request *);
typedef void (unplug_fn) (request_queue_t *);
struct bio_vec;
typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
typedef void (activity_fn) (void *data, int rw);
typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
typedef void (softirq_done_fn)(struct request *);
enum blk_queue_state {
Queue_down,
Queue_up,
};
struct blk_queue_tag {
struct request **tag_index; /* map of busy tags */
unsigned long *tag_map; /* bit map of free/busy tags */
struct list_head busy_list; /* fifo list of busy tags */
int busy; /* current depth */
int max_depth; /* what we will send to device */
int real_max_depth; /* what the array can hold */
atomic_t refcnt; /* map can be shared */
};
struct request_queue
{
/*
* Together with queue_head for cacheline sharing
*/
struct list_head queue_head;
struct request *last_merge;
elevator_t *elevator;
/*
* the queue request freelist, one for reads and one for writes
*/
struct request_list rq;
request_fn_proc *request_fn;
merge_request_fn *back_merge_fn;
merge_request_fn *front_merge_fn;
merge_requests_fn *merge_requests_fn;
make_request_fn *make_request_fn;
prep_rq_fn *prep_rq_fn;
unplug_fn *unplug_fn;
merge_bvec_fn *merge_bvec_fn;
activity_fn *activity_fn;
issue_flush_fn *issue_flush_fn;
prepare_flush_fn *prepare_flush_fn;
softirq_done_fn *softirq_done_fn;
/*
* Dispatch queue sorting
*/
sector_t end_sector;
struct request *boundary_rq;
/*
* Auto-unplugging state
*/
struct timer_list unplug_timer;
int unplug_thresh; /* After this many requests */
unsigned long unplug_delay; /* After this many jiffies */
struct work_struct unplug_work;
struct backing_dev_info backing_dev_info;
/*
* The queue owner gets to use this for whatever they like.
* ll_rw_blk doesn't touch it.
*/
void *queuedata;
void *activity_data;
/*
* queue needs bounce pages for pages above this limit
*/
unsigned long bounce_pfn;
gfp_t bounce_gfp;
/*
* various queue flags, see QUEUE_* below
*/
unsigned long queue_flags;
/*
* protects queue structures from reentrancy. ->__queue_lock should
* _never_ be used directly, it is queue private. always use
* ->queue_lock.
*/
spinlock_t __queue_lock;
spinlock_t *queue_lock;
/*
* queue kobject
*/
struct kobject kobj;
/*
* queue settings
*/
unsigned long nr_requests; /* Max # of requests */
unsigned int nr_congestion_on;
unsigned int nr_congestion_off;
unsigned int nr_batching;
unsigned int max_sectors;
unsigned int max_hw_sectors;
unsigned short max_phys_segments;
unsigned short max_hw_segments;
unsigned short hardsect_size;
unsigned int max_segment_size;
unsigned long seg_boundary_mask;
unsigned int dma_alignment;
struct blk_queue_tag *queue_tags;
unsigned int nr_sorted;
unsigned int in_flight;
/*
* sg stuff
*/
unsigned int sg_timeout;
unsigned int sg_reserved_size;
int node;
struct blk_trace *blk_trace;
/*
* reserved for flush operations
*/
unsigned int ordered, next_ordered, ordseq;
int orderr, ordcolor;
struct request pre_flush_rq, bar_rq, post_flush_rq;
struct request *orig_bar_rq;
unsigned int bi_size;
struct mutex sysfs_lock;
};
#define RQ_INACTIVE (-1)
#define RQ_ACTIVE 1
#define RQ_SCSI_BUSY 0xffff
#define RQ_SCSI_DONE 0xfffe
#define RQ_SCSI_DISCONNECTING 0xffe0
#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
#define QUEUE_FLAG_READFULL 3 /* write queue has been filled */
#define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */
#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
enum {
/*
* Hardbarrier is supported with one of the following methods.
*
* NONE : hardbarrier unsupported
* DRAIN : ordering by draining is enough
* DRAIN_FLUSH : ordering by draining w/ pre and post flushes
* DRAIN_FUA : ordering by draining w/ pre flush and FUA write
* TAG : ordering by tag is enough
* TAG_FLUSH : ordering by tag w/ pre and post flushes
* TAG_FUA : ordering by tag w/ pre flush and FUA write
*/
QUEUE_ORDERED_NONE = 0x00,
QUEUE_ORDERED_DRAIN = 0x01,
QUEUE_ORDERED_TAG = 0x02,
QUEUE_ORDERED_PREFLUSH = 0x10,
QUEUE_ORDERED_POSTFLUSH = 0x20,
QUEUE_ORDERED_FUA = 0x40,
QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
/*
* Ordered operation sequence
*/
QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
QUEUE_ORDSEQ_DONE = 0x20,
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_flushing(q) ((q)->ordseq)
#define blk_fs_request(rq) ((rq)->flags & REQ_CMD)
#define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC)
#define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST)
#define blk_rq_started(rq) ((rq)->flags & REQ_STARTED)
#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq))
#define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND)
#define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME)
#define blk_pm_request(rq) \
((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
#define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED)
#define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER)
#define blk_fua_rq(rq) ((rq)->flags & REQ_FUA)
#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
#define rq_data_dir(rq) ((rq)->flags & 1)
static inline int blk_queue_full(struct request_queue *q, int rw)
{
if (rw == READ)
return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}
static inline void blk_set_queue_full(struct request_queue *q, int rw)
{
if (rw == READ)
set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
else
set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}
static inline void blk_clear_queue_full(struct request_queue *q, int rw)
{
if (rw == READ)
clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
else
clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}
/*
* mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
* it already be started by driver.
*/
#define RQ_NOMERGE_FLAGS \
(REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
#define rq_mergeable(rq) \
(!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
/*
* noop, requests are automagically marked as active/inactive by I/O
* scheduler -- see elv_next_request
*/
#define blk_queue_headactive(q, head_active)
/*
* q->prep_rq_fn return values
*/
#define BLKPREP_OK 0 /* serve it */
#define BLKPREP_KILL 1 /* fatal error, kill */
#define BLKPREP_DEFER 2 /* leave on queue */
extern unsigned long blk_max_low_pfn, blk_max_pfn;
/*
* standard bounce addresses:
*
* BLK_BOUNCE_HIGH : bounce all highmem pages
* BLK_BOUNCE_ANY : don't bounce anything
* BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
*/
#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT)
#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD)
#ifdef CONFIG_MMU
extern int init_emergency_isa_pool(void);
extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
#else
static inline int init_emergency_isa_pool(void)
{
return 0;
}
static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
{
}
#endif /* CONFIG_MMU */
#define rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
struct sec_size {
unsigned block_size;
unsigned block_size_bits;
};
extern int blk_register_queue(struct gendisk *disk);
extern void blk_unregister_queue(struct gendisk *disk);
extern void register_disk(struct gendisk *dev);
extern void generic_make_request(struct bio *bio);
extern void blk_put_request(struct request *);
extern void __blk_put_request(request_queue_t *, struct request *);
extern void blk_end_sync_rq(struct request *rq, int error);
extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
extern void blk_requeue_request(request_queue_t *, struct request *);
extern void blk_plug_device(request_queue_t *);
extern int blk_remove_plug(request_queue_t *);
extern void blk_recount_segments(request_queue_t *, struct bio *);
extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
extern void blk_start_queue(request_queue_t *q);
extern void blk_stop_queue(request_queue_t *q);
extern void blk_sync_queue(struct request_queue *q);
extern void __blk_stop_queue(request_queue_t *q);
extern void blk_run_queue(request_queue_t *);
extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
extern int blk_rq_unmap_user(struct bio *, unsigned int);
extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t);
extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
extern int blk_execute_rq(request_queue_t *, struct gendisk *,
struct request *, int);
extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *,
struct request *, int, rq_end_io_fn *);
static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
{
return bdev->bd_disk->queue;
}
static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
struct page *page)
{
if (bdi && bdi->unplug_io_fn)
bdi->unplug_io_fn(bdi, page);
}
static inline void blk_run_address_space(struct address_space *mapping)
{
if (mapping)
blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
/*
* end_request() and friends. Must be called with the request queue spinlock
* acquired. All functions called within end_request() _must_be_ atomic.
*
* Several drivers define their own end_request and call
* end_that_request_first() and end_that_request_last()
* for parts of the original function. This prevents
* code duplication in drivers.
*/
extern int end_that_request_first(struct request *, int, int);
extern int end_that_request_chunk(struct request *, int, int);
extern void end_that_request_last(struct request *, int);
extern void end_request(struct request *req, int uptodate);
extern void blk_complete_request(struct request *);
static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
{
if (blk_fs_request(rq))
return (nr_bytes >= (rq->hard_nr_sectors << 9));
else if (blk_pc_request(rq))
return nr_bytes >= rq->data_len;
return 0;
}
/*
* end_that_request_first/chunk() takes an uptodate argument. we account
* any value <= as an io error. 0 means -EIO for compatability reasons,
* any other < 0 value is the direct error type. An uptodate value of
* 1 indicates successful io completion
*/
#define end_io_error(uptodate) (unlikely((uptodate) <= 0))
static inline void blkdev_dequeue_request(struct request *req)
{
elv_dequeue_request(req->q, req);
}
/*
* This should be in elevator.h, but that requires pulling in rq and q
*/
static inline void elv_dispatch_add_tail(struct request_queue *q,
struct request *rq)
{
if (q->last_merge == rq)
q->last_merge = NULL;
q->nr_sorted--;
q->end_sector = rq_end_sector(rq);
q->boundary_rq = rq;
list_add_tail(&rq->queuelist, &q->queue_head);
}
/*
* Access functions for manipulating queue properties
*/
extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
spinlock_t *lock, int node_id);
extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
extern void blk_cleanup_queue(request_queue_t *);
extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
extern void blk_queue_bounce_limit(request_queue_t *, u64);
extern void blk_queue_max_sectors(request_queue_t *, unsigned int);
extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
extern void blk_queue_dma_alignment(request_queue_t *, int);
extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *);
extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
extern int blk_do_ordered(request_queue_t *, struct request **);
extern unsigned blk_ordered_cur_seq(request_queue_t *);
extern unsigned blk_ordered_req_seq(struct request *);
extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int);
extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
extern void generic_unplug_device(request_queue_t *);
extern void __generic_unplug_device(request_queue_t *);
extern long nr_blockdev_pages(void);
int blk_get_queue(request_queue_t *);
request_queue_t *blk_alloc_queue(gfp_t);
request_queue_t *blk_alloc_queue_node(gfp_t, int);
extern void blk_put_queue(request_queue_t *);
/*
* tag stuff
*/
#define blk_queue_tag_depth(q) ((q)->queue_tags->busy)
#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth)
#define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED)
extern int blk_queue_start_tag(request_queue_t *, struct request *);
extern struct request *blk_queue_find_tag(request_queue_t *, int);
extern void blk_queue_end_tag(request_queue_t *, struct request *);
extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
extern void blk_queue_free_tags(request_queue_t *);
extern int blk_queue_resize_tags(request_queue_t *, int);
extern void blk_queue_invalidate_tags(request_queue_t *);
extern long blk_congestion_wait(int rw, long timeout);
extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
extern int blkdev_issue_flush(struct block_device *, sector_t *);
#define MAX_PHYS_SEGMENTS 128
#define MAX_HW_SEGMENTS 128
#define SAFE_MAX_SECTORS 255
#define BLK_DEF_MAX_SECTORS 1024
#define MAX_SEGMENT_SIZE 65536
#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
static inline int queue_hardsect_size(request_queue_t *q)
{
int retval = 512;
if (q && q->hardsect_size)
retval = q->hardsect_size;
return retval;
}
static inline int bdev_hardsect_size(struct block_device *bdev)
{
return queue_hardsect_size(bdev_get_queue(bdev));
}
static inline int queue_dma_alignment(request_queue_t *q)
{
int retval = 511;
if (q && q->dma_alignment)
retval = q->dma_alignment;
return retval;
}
static inline int bdev_dma_aligment(struct block_device *bdev)
{
return queue_dma_alignment(bdev_get_queue(bdev));
}
#define blk_finished_io(nsects) do { } while (0)
#define blk_started_io(nsects) do { } while (0)
/* assumes size > 256 */
static inline unsigned int blksize_bits(unsigned int size)
{
unsigned int bits = 8;
do {
bits++;
size >>= 1;
} while (size > 256);
return bits;
}
static inline unsigned int block_size(struct block_device *bdev)
{
return bdev->bd_block_size;
}
typedef struct {struct page *v;} Sector;
unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
static inline void put_dev_sector(Sector p)
{
page_cache_release(p.v);
}
struct work_struct;
int kblockd_schedule_work(struct work_struct *work);
void kblockd_flush(void);
#ifdef CONFIG_LBD
# include <asm/div64.h>
# define sector_div(a, b) do_div(a, b)
#else
# define sector_div(n, b)( \
{ \
int _res; \
_res = (n) % (b); \
(n) /= (b); \
_res; \
} \
)
#endif
#define MODULE_ALIAS_BLOCKDEV(major,minor) \
MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
MODULE_ALIAS("block-major-" __stringify(major) "-*")
#endif