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 */
16 struct 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 */
39 enum {
40 RC_UNUSED,
41 RC_INPROG,
42 RC_DONE
43 };
44
45 /* return values */
46 enum {
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 */
59 enum {
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
70 int nfsd_reply_cache_init(void);
71 void nfsd_reply_cache_shutdown(void);
72 int nfsd_cache_lookup(struct svc_rqst *, int);
73 void nfsd_cache_update(struct svc_rqst *, int, __be32 *);
74
75 #ifdef CONFIG_NFSD_V4
76 void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp);
77 #else /* CONFIG_NFSD_V4 */
nfsd4_set_statp(struct svc_rqst * rqstp,__be32 * statp)78 static inline void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp)
79 {
80 }
81 #endif /* CONFIG_NFSD_V4 */
82
83 #endif /* NFSCACHE_H */
84