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

 1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 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
12#include <linux/sunrpc/svc.h>
13#include "netns.h"
14
15/*
16 * Representation of a reply cache entry.
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.
21 */
22struct nfsd_cacherep {
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;
33
34	struct rb_node		c_node;
35	struct list_head	c_lru;
36	unsigned char		c_state,	/* unused, inprog, done */
37				c_type,		/* status, buffer */
38				c_secure : 1;	/* req came from port < 1024 */
 
 
 
 
 
39	unsigned long		c_timestamp;
40	union {
41		struct kvec	u_vec;
42		__be32		u_status;
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 */
50enum {
51	RC_UNUSED,
52	RC_INPROG,
53	RC_DONE
54};
55
56/* return values */
57enum {
58	RC_DROPIT,
59	RC_REPLY,
60	RC_DOIT
 
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 */
69enum {
70	RC_NOCACHE,
71	RC_REPLSTAT,
72	RC_REPLBUFF,
73};
74
75/* Cache entries expire after this time period */
76#define RC_EXPIRE		(120 * HZ)
77
78/* Checksum this amount of the request */
79#define RC_CSUMLEN		(256U)
80
81int	nfsd_drc_slab_create(void);
82void	nfsd_drc_slab_free(void);
83int	nfsd_reply_cache_init(struct nfsd_net *);
84void	nfsd_reply_cache_shutdown(struct nfsd_net *);
85int	nfsd_cache_lookup(struct svc_rqst *rqstp, unsigned int start,
86			  unsigned int len, struct nfsd_cacherep **cacherep);
87void	nfsd_cache_update(struct svc_rqst *rqstp, struct nfsd_cacherep *rp,
88			  int cachetype, __be32 *statp);
89int	nfsd_reply_cache_stats_show(struct seq_file *m, void *v);
 
 
 
90
91#endif /* NFSCACHE_H */