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

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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.
 *
 * Note that we use a sockaddr_in6 to hold the address instead of the more
 * typical sockaddr_storage. This is for space reasons, since sockaddr_storage
 * is much larger than a sockaddr_in6.
 */
struct svc_cacherep {
	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_in6	c_addr;
	__be32			c_xid;
	u32			c_prot;
	u32			c_proc;
	u32			c_vers;
	unsigned int		c_len;
	__wsum			c_csum;
	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
};

/*
 * 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)

/* Cache entries expire after this time period */
#define RC_EXPIRE		(120 * HZ)

/* Checksum this amount of the request */
#define RC_CSUMLEN		(256U)

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

#endif /* NFSCACHE_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4	2	/*
1da177e4 LT	3	* Request reply cache. This was heavily inspired by the
	4	* implementation in 4.3BSD/4.4BSD.
	5	*
	6	* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
	7	*/
	8
	9	#ifndef NFSCACHE_H
	10	#define NFSCACHE_H
	11
72579ac9	12	#include <linux/sunrpc/svc.h>
1da177e4 LT	13
1da177e4 LT	14	/*
fca4217c	15	* Representation of a reply cache entry.
7b9e8522 JL	16	*
	17	* Note that we use a sockaddr_in6 to hold the address instead of the more
	18	* typical sockaddr_storage. This is for space reasons, since sockaddr_storage
	19	* is much larger than a sockaddr_in6.
1da177e4 LT	20	*/
1da177e4 LT	21	struct svc_cacherep {
1da177e4 LT	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 */
7b9e8522	27	struct sockaddr_in6 c_addr;
c7afef1f	28	__be32 c_xid;
1da177e4 LT	29	u32 c_prot;
	30	u32 c_proc;
	31	u32 c_vers;
01a7decf JL	32	unsigned int c_len;
01a7decf JL	33	__wsum c_csum;
1da177e4 LT	34	unsigned long c_timestamp;
	35	union {
	36	struct kvec u_vec;
c7afef1f	37	__be32 u_status;
1da177e4 LT	38	} c_u;
	39	};
	40
	41	#define c_replvec c_u.u_vec
	42	#define c_replstat c_u.u_status
	43
	44	/* cache entry states */
	45	enum {
	46	RC_UNUSED,
	47	RC_INPROG,
	48	RC_DONE
	49	};
	50
	51	/* return values */
	52	enum {
	53	RC_DROPIT,
	54	RC_REPLY,
09662d58	55	RC_DOIT
1da177e4 LT	56	};
	57
	58	/*
	59	* Cache types.
	60	* We may want to add more types one day, e.g. for diropres and
	61	* attrstat replies. Using cache entries with fixed length instead
	62	* of buffer pointers may be more efficient.
	63	*/
	64	enum {
	65	RC_NOCACHE,
	66	RC_REPLSTAT,
	67	RC_REPLBUFF,
	68	};
	69
	70	/*
	71	* If requests are retransmitted within this interval, they're dropped.
	72	*/
	73	#define RC_DELAY (HZ/5)
	74
d1a0774d JL	75	/* Cache entries expire after this time period */
	76	#define RC_EXPIRE (120 * HZ)
	77
01a7decf JL	78	/* Checksum this amount of the request */
	79	#define RC_CSUMLEN (256U)
	80
d5c3428b BF	81	int nfsd_reply_cache_init(void);
d5c3428b BF	82	void nfsd_reply_cache_shutdown(void);
1091006c	83	int nfsd_cache_lookup(struct svc_rqst *);
c7afef1f	84	void nfsd_cache_update(struct svc_rqst , int, __be32 );
a2f999a3	85	int nfsd_reply_cache_stats_open(struct inode , struct file );
04826f43	86
1da177e4	87	#endif /* NFSCACHE_H */