[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>
#include "netns.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(struct nfsd_net *);
void	nfsd_reply_cache_shutdown(struct nfsd_net *);
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>
3ba75830	13	#include "netns.h"
1da177e4 LT	14
1da177e4 LT	15	/*
fca4217c	16	* Representation of a reply cache entry.
7b9e8522 JL	17	*
	18	* Note that we use a sockaddr_in6 to hold the address instead of the more
	19	* typical sockaddr_storage. This is for space reasons, since sockaddr_storage
	20	* is much larger than a sockaddr_in6.
1da177e4 LT	21	*/
1da177e4 LT	22	struct svc_cacherep {
ed00c2f6 TM	23	struct {
	24	/* Keep often-read xid, csum in the same cache line: */
	25	__be32 k_xid;
	26	__wsum k_csum;
	27	u32 k_proc;
	28	u32 k_prot;
	29	u32 k_vers;
	30	unsigned int k_len;
	31	struct sockaddr_in6 k_addr;
	32	} c_key;
1da177e4	33
736c6625	34	struct rb_node c_node;
ed00c2f6	35	struct list_head c_lru;
1da177e4 LT	36	unsigned char c_state, /* unused, inprog, done */
	37	c_type, /* status, buffer */
	38	c_secure : 1; /* req came from port < 1024 */
1da177e4 LT	39	unsigned long c_timestamp;
	40	union {
	41	struct kvec u_vec;
c7afef1f	42	__be32 u_status;
1da177e4 LT	43	} c_u;
	44	};
	45
	46	#define c_replvec c_u.u_vec
	47	#define c_replstat c_u.u_status
	48
	49	/* cache entry states */
	50	enum {
	51	RC_UNUSED,
	52	RC_INPROG,
	53	RC_DONE
	54	};
	55
	56	/* return values */
	57	enum {
	58	RC_DROPIT,
	59	RC_REPLY,
09662d58	60	RC_DOIT
1da177e4 LT	61	};
	62
	63	/*
	64	* Cache types.
	65	* We may want to add more types one day, e.g. for diropres and
	66	* attrstat replies. Using cache entries with fixed length instead
	67	* of buffer pointers may be more efficient.
	68	*/
	69	enum {
	70	RC_NOCACHE,
	71	RC_REPLSTAT,
	72	RC_REPLBUFF,
	73	};
	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
3ba75830 BF	81	int nfsd_reply_cache_init(struct nfsd_net *);
3ba75830 BF	82	void nfsd_reply_cache_shutdown(struct nfsd_net *);
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 */