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/sched.h> 15 16/* 17 * Representation of a reply cache entry. The first two members *must* 18 * be hash_next and hash_prev. 19 */ 20struct svc_cacherep { 21 struct svc_cacherep * c_hash_next; 22 struct svc_cacherep * c_hash_prev; 23 struct svc_cacherep * c_lru_next; 24 struct svc_cacherep * c_lru_prev; 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 svc_buf u_buffer; 36 u32 u_status; 37 } c_u; 38}; 39 40#define c_replbuf c_u.u_buffer 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 */ 82