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