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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
13#include <linux/in.h>
14#include <linux/uio.h>
15
16/*
17 * Representation of a reply cache entry.
18 */
19struct svc_cacherep {
20 struct hlist_node c_hash;
21 struct list_head c_lru;
22
23 unsigned char c_state, /* unused, inprog, done */
24 c_type, /* status, buffer */
25 c_secure : 1; /* req came from port < 1024 */
26 struct sockaddr_in c_addr;
27 __be32 c_xid;
28 u32 c_prot;
29 u32 c_proc;
30 u32 c_vers;
31 unsigned long c_timestamp;
32 union {
33 struct kvec u_vec;
34 __be32 u_status;
35 } c_u;
36};
37
38#define c_replvec c_u.u_vec
39#define c_replstat c_u.u_status
40
41/* cache entry states */
42enum {
43 RC_UNUSED,
44 RC_INPROG,
45 RC_DONE
46};
47
48/* return values */
49enum {
50 RC_DROPIT,
51 RC_REPLY,
52 RC_DOIT,
53 RC_INTR
54};
55
56/*
57 * Cache types.
58 * We may want to add more types one day, e.g. for diropres and
59 * attrstat replies. Using cache entries with fixed length instead
60 * of buffer pointers may be more efficient.
61 */
62enum {
63 RC_NOCACHE,
64 RC_REPLSTAT,
65 RC_REPLBUFF,
66};
67
68/*
69 * If requests are retransmitted within this interval, they're dropped.
70 */
71#define RC_DELAY (HZ/5)
72
73int nfsd_reply_cache_init(void);
74void nfsd_reply_cache_shutdown(void);
75int nfsd_cache_lookup(struct svc_rqst *, int);
76void nfsd_cache_update(struct svc_rqst *, int, __be32 *);
77
78#ifdef CONFIG_NFSD_V4
79void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp);
80#else /* CONFIG_NFSD_V4 */
81static inline void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp)
82{
83}
84#endif /* CONFIG_NFSD_V4 */
85
86#endif /* NFSCACHE_H */