blob: 1cc2b49c11e3d84a2630b341b82bcb2087082cb3 (
plain) (
blame)
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
|
#ifndef LINUX_DNBD_CACHE_H
#define LINUX_DNBD_CACHE_H 1
#include <linux/rbtree.h>
#include <linux/blkdev.h>
#include "../common/dnbd-cliserv.h"
/* node for red-black tree */
struct cache_node {
struct rb_node rb_node;
sector_t rb_key;
sector_t rb_data;
/* previous and next node used for LRU */
struct cache_node *prev;
struct cache_node *next;
};
typedef struct cache_node cache_node_t;
/* cache characteristics */
struct dnbd_cache {
int active; /* !0 when cache active */
char *fname; /* cache file name */
int fd; /* cache file descriptor */
struct file *filp; /* cache file structure */
struct rb_root root; /* root node of cache */
sector_t max_blocks; /* maximum of cached blocks */
sector_t used_blocks; /* current used blocks */
size_t blksize;
struct cache_node *head; /* head of LRU list */
struct cache_node *tail; /* tail of LRU list */
spinlock_t lock;
struct semaphore sema;
int (*insert) (struct dnbd_cache * cache, sector_t sector, void *buf);
int (*search) (struct dnbd_cache * cache, struct request *req);
void (*clean) (struct dnbd_cache * cache);
long hits; /* statistics */
long miss;
long lru;
};
typedef struct dnbd_cache dnbd_cache_t;
int dnbd_cache_init(dnbd_cache_t * cache);
int dnbd_cache_set(dnbd_cache_t * dcache, struct dnbd_file __user * cachefile, size_t blksize);
#endif
|
