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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | #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;
int elevator_latency;
};
typedef void (request_fn_proc) (void);
typedef struct request ** (queue_proc) (kdev_t dev);
typedef struct elevator_s
{
int read_latency;
int write_latency;
unsigned int queue_ID;
} elevator_t;
#define ELEVATOR_DEFAULTS \
((elevator_t) { \
256, /* read_latency */ \
512, /* write_latency */ \
0 /* queue_ID */ \
})
extern int blkelv_ioctl(kdev_t, unsigned long, unsigned long);
typedef struct blkelv_ioctl_arg_s {
int queue_ID;
int read_latency;
int write_latency;
int max_bomb_segments;
} blkelv_ioctl_arg_t;
#define BLKELVGET _IOR(0x12,106,sizeof(blkelv_ioctl_arg_t))
#define BLKELVSET _IOW(0x12,107,sizeof(blkelv_ioctl_arg_t))
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;
elevator_t elevator;
};
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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