1 files changed, 49 insertions, 0 deletions
diff --git a/kernel/cache.h b/kernel/cache.h
new file mode 100644
index 0000000..1cc2b49
--- /dev/null
+++ b/kernel/cache.h
@@ -0,0 +1,49 @@
+#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