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#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_s;

typedef struct elevator_s elevator_t;

struct request_pm_state;

#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;

};

/*

 * 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;

        pid_t pid;

        /*

         * 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;

};

void put_io_context(struct io_context *ioc);

void exit_io_context(void);

struct io_context *get_io_context(int 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_list {

        int count[2];

        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; /* looking for ->queue? you must _not_

                                     * access it directly, use

                                     * blkdev_dequeue_request! */

        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;

        /* no. of segments left to submit in the current bio */

        unsigned short nr_cbio_segments;

        /* no. of sectors left to submit in the current bio */

        unsigned long nr_cbio_sectors;

        struct bio *cbio;               /* next bio to submit */

        struct bio *bio;                /* next unfinished bio to complete */

        struct bio *biotail;

        void *elevator_private;

        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;

        /*

         * For Power Management requests

         */

        struct request_pm_state *pm;

};

/*

 * 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_SOFTBARRIER,      /* may not be passed by ioscheduler */

        __REQ_HARDBARRIER,      /* may not be passed by drive either */

        __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 */

        /*

         * 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_IDETAPE_PC1,      /* packet command (first stage) */

        __REQ_IDETAPE_PC2,      /* packet command (second stage) */

        __REQ_IDETAPE_READ,

        __REQ_IDETAPE_WRITE,

        __REQ_IDETAPE_READ_BUFFER,

        __REQ_NR_BITS,          /* stops here */

};

#define REQ_RW          (1 << __REQ_RW)

#define REQ_FAILFAST    (1 << __REQ_FAILFAST)

#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)

#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)

#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_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_IDETAPE_PC1 (1 << __REQ_IDETAPE_PC1)

#define REQ_IDETAPE_PC2 (1 << __REQ_IDETAPE_PC2)

#define REQ_IDETAPE_READ        (1 << __REQ_IDETAPE_READ)

#define REQ_IDETAPE_WRITE       (1 << __REQ_IDETAPE_WRITE)

#define REQ_IDETAPE_READ_BUFFER (1 << __REQ_IDETAPE_READ_BUFFER)

/*

 * 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) (void *q);

struct bio_vec;

typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);

typedef void (activity_fn) (void *data, int rw);

enum blk_queue_state {

        Queue_down,

        Queue_up,

};

#define BLK_TAGS_PER_LONG       (sizeof(unsigned long) * 8)

#define BLK_TAGS_MASK           (BLK_TAGS_PER_LONG - 1)

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;

        /*

         * 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;

        int                     bounce_gfp;

        struct list_head        plug_list;

        /*

         * various queue flags, see QUEUE_* below

         */

        unsigned long           queue_flags;

        /*

         * protects queue structures from reentrancy

         */

        spinlock_t              *queue_lock;

        /*

         * queue kobject

         */

        struct kobject kobj;

        /*

         * queue settings

         */

        unsigned long           nr_requests;    /* Max # of requests */

        unsigned short          max_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;

        atomic_t                refcnt;

        /*

         * sg stuff

         */

        unsigned int            sg_timeout;

        unsigned int            sg_reserved_size;

};

#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 blk_queue_plugged(q)    !list_empty(&(q)->plug_list)

#define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)

#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_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 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)

/* current index into bio being processed for submission */

#define blk_rq_idx(rq)  ((rq)->cbio->bi_vcnt - (rq)->nr_cbio_segments)

/* current bio vector being processed */

#define blk_rq_vec(rq)  (bio_iovec_idx((rq)->cbio, blk_rq_idx(rq)))

/* current offset with respect to start of the segment being submitted */

#define blk_rq_offset(rq) \

        (((rq)->hard_cur_sectors - (rq)->current_nr_sectors) << 9)

/*

 * temporarily mapping a (possible) highmem bio (typically for PIO transfer)

 */

/* Assumes rq->cbio != NULL */

static inline char * rq_map_buffer(struct request *rq, unsigned long *flags)

{

        return (__bio_kmap_irq(rq->cbio, blk_rq_idx(rq), flags)

                + blk_rq_offset(rq));

}

static inline void rq_unmap_buffer(char *buffer, unsigned long *flags)

{

        __bio_kunmap_irq(buffer, flags);

}

/*

 * 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_attempt_remerge(request_queue_t *, struct request *);

extern void __blk_attempt_remerge(request_queue_t *, struct request *);

extern struct request *blk_get_request(request_queue_t *, int, int);

extern void blk_put_request(struct request *);

extern void blk_insert_request(request_queue_t *, struct request *, int, void *, int);

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 inline int blk_phys_contig_segment(request_queue_t *q, struct bio *, struct bio *);

extern inline int blk_hw_contig_segment(request_queue_t *q, struct bio *, struct bio *);

extern int scsi_cmd_ioctl(struct block_device *, unsigned int, unsigned long);

extern void blk_start_queue(request_queue_t *q);

extern void blk_stop_queue(request_queue_t *q);

extern void __blk_stop_queue(request_queue_t *q);

extern void blk_run_queue(request_queue_t *q);

extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);

static inline request_queue_t *bdev_get_queue(struct block_device *bdev)

{

        return bdev->bd_disk->queue;

}

/*

 * 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 *);

extern int process_that_request_first(struct request *, unsigned int);

extern void end_request(struct request *req, int uptodate);

static inline void blkdev_dequeue_request(struct request *req)

{

        BUG_ON(list_empty(&req->queuelist));

        list_del_init(&req->queuelist);

        if (req->q)

                elv_remove_request(req->q, req);

}

/*

 * Access functions for manipulating queue properties

 */

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 short);

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 struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);

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(void *);

extern long nr_blockdev_pages(void);

int blk_get_queue(request_queue_t *);

request_queue_t *blk_alloc_queue(int);

#define blk_put_queue(q) blk_cleanup_queue((q))

/*

 * 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 void blk_congestion_wait(int rw, long timeout);

extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);

extern void blk_rq_prep_restart(struct request *);

#define MAX_PHYS_SEGMENTS 128

#define MAX_HW_SEGMENTS 128

#define MAX_SECTORS 255

#define MAX_SEGMENT_SIZE        65536

#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)

extern void drive_stat_acct(struct request *, int, int);

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;

}

extern 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