]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - include/linux/nfsd/cache.h
Linux-2.6.12-rc2
[mirror_ubuntu-artful-kernel.git] / include / linux / nfsd / cache.h
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 */
21 struct 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 */
44 enum {
45 RC_UNUSED,
46 RC_INPROG,
47 RC_DONE
48 };
49
50 /* return values */
51 enum {
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 */
64 enum {
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
75 void nfsd_cache_init(void);
76 void nfsd_cache_shutdown(void);
77 int nfsd_cache_lookup(struct svc_rqst *, int);
78 void nfsd_cache_update(struct svc_rqst *, int, u32 *);
79
80 #endif /* __KERNEL__ */
81 #endif /* NFSCACHE_H */