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#ifndef _LINUX_BLKDEV_H
#define _LINUX_BLKDEV_H
#include <linux/major.h>
#include <linux/sched.h>
#include <linux/genhd.h>
#include <linux/tqueue.h>
/*
* Ok, this is an expanded form so that we can use the same
* request for paging requests when that is implemented. In
* paging, 'bh' is NULL, and the semaphore is used to wait
* for read/write completion.
*/
struct request {
volatile int rq_status; /* should split this into a few status bits */
#define RQ_INACTIVE (-1)
#define RQ_ACTIVE 1
#define RQ_SCSI_BUSY 0xffff
#define RQ_SCSI_DONE 0xfffe
#define RQ_SCSI_DISCONNECTING 0xffe0
kdev_t rq_dev;
int cmd; /* READ or WRITE */
int errors;
unsigned long sector;
unsigned long nr_sectors;
unsigned long nr_segments;
unsigned long current_nr_sectors;
char * buffer;
struct semaphore * sem;
struct buffer_head * bh;
struct buffer_head * bhtail;
struct request * next;
};
typedef void (request_fn_proc) (void);
typedef struct request ** (queue_proc) (kdev_t dev);
struct blk_dev_struct {
request_fn_proc *request_fn;
/*
* queue_proc has to be atomic
*/
queue_proc *queue;
void *data;
struct request *current_request;
struct request plug;
struct tq_struct plug_tq;
};
struct sec_size {
unsigned block_size;
unsigned block_size_bits;
};
extern struct sec_size * blk_sec[MAX_BLKDEV];
extern struct blk_dev_struct blk_dev[MAX_BLKDEV];
extern struct wait_queue * wait_for_request;
extern void resetup_one_dev(struct gendisk *dev, int drive);
extern void unplug_device(void * data);
extern void make_request(int major,int rw, struct buffer_head * bh);
/* md needs this function to remap requests */
extern int md_map (int minor, kdev_t *rdev, unsigned long *rsector, unsigned long size);
extern int md_make_request (int minor, int rw, struct buffer_head * bh);
extern int md_error (kdev_t mddev, kdev_t rdev);
extern int * blk_size[MAX_BLKDEV];
extern int * blksize_size[MAX_BLKDEV];
extern int * hardsect_size[MAX_BLKDEV];
extern int * max_readahead[MAX_BLKDEV];
extern int * max_sectors[MAX_BLKDEV];
extern int * max_segments[MAX_BLKDEV];
#define MAX_SECTORS 128
#define MAX_SEGMENTS MAX_SECTORS
#define PageAlignSize(size) (((size) + PAGE_SIZE -1) & PAGE_MASK)
#if 0 /* small readahead */
#define MAX_READAHEAD PageAlignSize(4096*7)
#define MIN_READAHEAD PageAlignSize(4096*2)
#else /* large readahead */
#define MAX_READAHEAD PageAlignSize(4096*31)
#define MIN_READAHEAD PageAlignSize(4096*3)
#endif
#endif
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