/* * include/linux/nfsd/cache.h * * Request reply cache. This was heavily inspired by the * implementation in 4.3BSD/4.4BSD. * * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */#ifndef NFSCACHE_H#define NFSCACHE_H#ifdef __KERNEL__#include <linux/sched.h>/* * Representation of a reply cache entry. The first two members *must* * be hash_next and hash_prev. */struct svc_cacherep {	struct svc_cacherep *	c_hash_next;	struct svc_cacherep *	c_hash_prev;	struct svc_cacherep *	c_lru_next;	struct svc_cacherep *	c_lru_prev;	unsigned char		c_state,	/* unused, inprog, done */				c_type,		/* status, buffer */				c_secure : 1;	/* req came from port < 1024 */	struct in_addr		c_client;	u32			c_xid;	u32			c_proc;	unsigned long		c_timestamp;	union {		struct svc_buf	u_buffer;		u32		u_status;	}			c_u;};#define c_replbuf		c_u.u_buffer#define c_replstat		c_u.u_status/* cache entry states */enum {	RC_UNUSED,	RC_INPROG,	RC_DONE};/* return values */enum {	RC_DROPIT,	RC_REPLY,	RC_DOIT,	RC_INTR};/* * Cache types. * We may want to add more types one day, e.g. for diropres and * attrstat replies. Using cache entries with fixed length instead * of buffer pointers may be more efficient. */enum {	RC_NOCACHE,	RC_REPLSTAT,	RC_REPLBUFF,};/* * If requests are retransmitted within this interval, they're dropped. */#define RC_DELAY		(HZ/5)void	nfsd_cache_init(void);void	nfsd_cache_shutdown(void);int	nfsd_cache_lookup(struct svc_rqst *, int);void	nfsd_cache_update(struct svc_rqst *, int, u32 *);#endif /* __KERNEL__ */#endif /* NFSCACHE_H */