[linux-2.6-block.git] / fs / nfsd / cache.h

/*
 * 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

#include <linux/sunrpc/svc.h>

/*
 * Representation of a reply cache entry.
 */
struct svc_cacherep {
	struct hlist_node	c_hash;
	struct list_head	c_lru;

	unsigned char		c_state,	/* unused, inprog, done */
				c_type,		/* status, buffer */
				c_secure : 1;	/* req came from port < 1024 */
	struct sockaddr_in	c_addr;
	__be32			c_xid;
	u32			c_prot;
	u32			c_proc;
	u32			c_vers;
	unsigned long		c_timestamp;
	union {
		struct kvec	u_vec;
		__be32		u_status;
	}			c_u;
};

#define c_replvec		c_u.u_vec
#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)

int	nfsd_reply_cache_init(void);
void	nfsd_reply_cache_shutdown(void);
int	nfsd_cache_lookup(struct svc_rqst *, int);
void	nfsd_cache_update(struct svc_rqst *, int, __be32 *);

#ifdef CONFIG_NFSD_V4
void	nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp);
#else  /* CONFIG_NFSD_V4 */
static inline void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp)
{
}
#endif /* CONFIG_NFSD_V4 */

#endif /* NFSCACHE_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* include/linux/nfsd/cache.h
	3	*
	4	* Request reply cache. This was heavily inspired by the
	5	* implementation in 4.3BSD/4.4BSD.
	6	*
	7	* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
	8	*/
	9
	10	#ifndef NFSCACHE_H
	11	#define NFSCACHE_H
	12
72579ac9	13	#include <linux/sunrpc/svc.h>
1da177e4 LT	14
1da177e4 LT	15	/*
fca4217c	16	* Representation of a reply cache entry.
1da177e4 LT	17	*/
	18	struct svc_cacherep {
	19	struct hlist_node c_hash;
	20	struct list_head c_lru;
	21
	22	unsigned char c_state, /* unused, inprog, done */
	23	c_type, /* status, buffer */
	24	c_secure : 1; /* req came from port < 1024 */
	25	struct sockaddr_in c_addr;
c7afef1f	26	__be32 c_xid;
1da177e4 LT	27	u32 c_prot;
	28	u32 c_proc;
	29	u32 c_vers;
	30	unsigned long c_timestamp;
	31	union {
	32	struct kvec u_vec;
c7afef1f	33	__be32 u_status;
1da177e4 LT	34	} c_u;
	35	};
	36
	37	#define c_replvec c_u.u_vec
	38	#define c_replstat c_u.u_status
	39
	40	/* cache entry states */
	41	enum {
	42	RC_UNUSED,
	43	RC_INPROG,
	44	RC_DONE
	45	};
	46
	47	/* return values */
	48	enum {
	49	RC_DROPIT,
	50	RC_REPLY,
	51	RC_DOIT,
	52	RC_INTR
	53	};
	54
	55	/*
	56	* Cache types.
	57	* We may want to add more types one day, e.g. for diropres and
	58	* attrstat replies. Using cache entries with fixed length instead
	59	* of buffer pointers may be more efficient.
	60	*/
	61	enum {
	62	RC_NOCACHE,
	63	RC_REPLSTAT,
	64	RC_REPLBUFF,
	65	};
	66
	67	/*
	68	* If requests are retransmitted within this interval, they're dropped.
	69	*/
	70	#define RC_DELAY (HZ/5)
	71
d5c3428b BF	72	int nfsd_reply_cache_init(void);
d5c3428b BF	73	void nfsd_reply_cache_shutdown(void);
1da177e4	74	int nfsd_cache_lookup(struct svc_rqst *, int);
c7afef1f	75	void nfsd_cache_update(struct svc_rqst , int, __be32 );
04826f43 BH	76
04826f43 BH	77	#ifdef CONFIG_NFSD_V4
074fe897	78	void nfsd4_set_statp(struct svc_rqst rqstp, __be32 statp);
04826f43 BH	79	#else /* CONFIG_NFSD_V4 */
	80	static inline void nfsd4_set_statp(struct svc_rqst rqstp, __be32 statp)
	81	{
	82	}
	83	#endif /* CONFIG_NFSD_V4 */
1da177e4	84
1da177e4	85	#endif /* NFSCACHE_H */