[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 {
		/* Keep often-read xid, csum in the same cache line: */
		__be32			k_xid;
		__wsum			k_csum;
		u32			k_proc;
		u32			k_prot;
		u32			k_vers;
		unsigned int		k_len;
		struct sockaddr_in6	k_addr;
	} c_key;

	struct rb_node		c_node;
	struct list_head	c_lru;
	unsigned char		c_state,	/* unused, inprog, done */
				c_type,		/* status, buffer */
				c_secure : 1;	/* req came from port < 1024 */
	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,
};

/* 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 {
ed00c2f6 TM	22	struct {
	23	/* Keep often-read xid, csum in the same cache line: */
	24	__be32 k_xid;
	25	__wsum k_csum;
	26	u32 k_proc;
	27	u32 k_prot;
	28	u32 k_vers;
	29	unsigned int k_len;
	30	struct sockaddr_in6 k_addr;
	31	} c_key;
1da177e4	32
736c6625	33	struct rb_node c_node;
ed00c2f6	34	struct list_head c_lru;
1da177e4 LT	35	unsigned char c_state, /* unused, inprog, done */
	36	c_type, /* status, buffer */
	37	c_secure : 1; /* req came from port < 1024 */
1da177e4 LT	38	unsigned long c_timestamp;
	39	union {
	40	struct kvec u_vec;
c7afef1f	41	__be32 u_status;
1da177e4 LT	42	} c_u;
	43	};
	44
	45	#define c_replvec c_u.u_vec
	46	#define c_replstat c_u.u_status
	47
	48	/* cache entry states */
	49	enum {
	50	RC_UNUSED,
	51	RC_INPROG,
	52	RC_DONE
	53	};
	54
	55	/* return values */
	56	enum {
	57	RC_DROPIT,
	58	RC_REPLY,
09662d58	59	RC_DOIT
1da177e4 LT	60	};
	61
	62	/*
	63	* Cache types.
	64	* We may want to add more types one day, e.g. for diropres and
	65	* attrstat replies. Using cache entries with fixed length instead
	66	* of buffer pointers may be more efficient.
	67	*/
	68	enum {
	69	RC_NOCACHE,
	70	RC_REPLSTAT,
	71	RC_REPLBUFF,
	72	};
	73
d1a0774d JL	74	/* Cache entries expire after this time period */
	75	#define RC_EXPIRE (120 * HZ)
	76
01a7decf JL	77	/* Checksum this amount of the request */
	78	#define RC_CSUMLEN (256U)
	79
d5c3428b BF	80	int nfsd_reply_cache_init(void);
d5c3428b BF	81	void nfsd_reply_cache_shutdown(void);
1091006c	82	int nfsd_cache_lookup(struct svc_rqst *);
c7afef1f	83	void nfsd_cache_update(struct svc_rqst , int, __be32 );
a2f999a3	84	int nfsd_reply_cache_stats_open(struct inode , struct file );
04826f43	85
1da177e4	86	#endif /* NFSCACHE_H */