[mirror_ubuntu-artful-kernel.git] / include / linux / 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/in.h>
#include <linux/uio.h>

/*
 * Representation of a reply cache entry. The first two members *must*
 * be hash_next and hash_prev.
 */
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 *);
void	nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp);

#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
1da177e4 LT	13	#include <linux/in.h>
	14	#include <linux/uio.h>
	15
	16	/*
	17	* Representation of a reply cache entry. The first two members must
	18	* be hash_next and hash_prev.
	19	*/
	20	struct svc_cacherep {
	21	struct hlist_node c_hash;
	22	struct list_head c_lru;
	23
	24	unsigned char c_state, /* unused, inprog, done */
	25	c_type, /* status, buffer */
	26	c_secure : 1; /* req came from port < 1024 */
	27	struct sockaddr_in c_addr;
c7afef1f	28	__be32 c_xid;
1da177e4 LT	29	u32 c_prot;
	30	u32 c_proc;
	31	u32 c_vers;
	32	unsigned long c_timestamp;
	33	union {
	34	struct kvec u_vec;
c7afef1f	35	__be32 u_status;
1da177e4 LT	36	} c_u;
	37	};
	38
	39	#define c_replvec c_u.u_vec
	40	#define c_replstat c_u.u_status
	41
	42	/* cache entry states */
	43	enum {
	44	RC_UNUSED,
	45	RC_INPROG,
	46	RC_DONE
	47	};
	48
	49	/* return values */
	50	enum {
	51	RC_DROPIT,
	52	RC_REPLY,
	53	RC_DOIT,
	54	RC_INTR
	55	};
	56
	57	/*
	58	* Cache types.
	59	* We may want to add more types one day, e.g. for diropres and
	60	* attrstat replies. Using cache entries with fixed length instead
	61	* of buffer pointers may be more efficient.
	62	*/
	63	enum {
	64	RC_NOCACHE,
	65	RC_REPLSTAT,
	66	RC_REPLBUFF,
	67	};
	68
	69	/*
	70	* If requests are retransmitted within this interval, they're dropped.
	71	*/
	72	#define RC_DELAY (HZ/5)
	73
d5c3428b BF	74	int nfsd_reply_cache_init(void);
d5c3428b BF	75	void nfsd_reply_cache_shutdown(void);
1da177e4	76	int nfsd_cache_lookup(struct svc_rqst *, int);
c7afef1f	77	void nfsd_cache_update(struct svc_rqst , int, __be32 );
074fe897	78	void nfsd4_set_statp(struct svc_rqst rqstp, __be32 statp);
1da177e4	79
1da177e4	80	#endif /* NFSCACHE_H */