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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#ifdef __KERNEL__
14#include <linux/in.h>
15#include <linux/uio.h>
16
17/*
18 * Representation of a reply cache entry. The first two members *must*
19 * be hash_next and hash_prev.
20 */
21struct svc_cacherep {
22 struct hlist_node c_hash;
23 struct list_head c_lru;
24
25 unsigned char c_state, /* unused, inprog, done */
26 c_type, /* status, buffer */
27 c_secure : 1; /* req came from port < 1024 */
28 struct sockaddr_in c_addr;
29 u32 c_xid;
30 u32 c_prot;
31 u32 c_proc;
32 u32 c_vers;
33 unsigned long c_timestamp;
34 union {
35 struct kvec u_vec;
36 u32 u_status;
37 } c_u;
38};
39
40#define c_replvec c_u.u_vec
41#define c_replstat c_u.u_status
42
43/* cache entry states */
44enum {
45 RC_UNUSED,
46 RC_INPROG,
47 RC_DONE
48};
49
50/* return values */
51enum {
52 RC_DROPIT,
53 RC_REPLY,
54 RC_DOIT,
55 RC_INTR
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 */
64enum {
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
75void nfsd_cache_init(void);
76void nfsd_cache_shutdown(void);
77int nfsd_cache_lookup(struct svc_rqst *, int);
78void nfsd_cache_update(struct svc_rqst *, int, u32 *);
79
80#endif /* __KERNEL__ */
81#endif /* NFSCACHE_H */