1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * %sccs.include.redist.c% 9 * 10 * @(#)nfs_srvcache.c 8.2 (Berkeley) 08/18/94 11 */ 12 13 /* 14 * Reference: Chet Juszczak, "Improving the Performance and Correctness 15 * of an NFS Server", in Proc. Winter 1989 USENIX Conference, 16 * pages 53-63. San Diego, February 1989. 17 */ 18 #include <sys/param.h> 19 #include <sys/vnode.h> 20 #include <sys/mount.h> 21 #include <sys/kernel.h> 22 #include <sys/systm.h> 23 #include <sys/proc.h> 24 #include <sys/mbuf.h> 25 #include <sys/malloc.h> 26 #include <sys/socket.h> 27 #include <sys/socketvar.h> 28 29 #include <netinet/in.h> 30 #ifdef ISO 31 #include <netiso/iso.h> 32 #endif 33 #include <nfs/nfsm_subs.h> 34 #include <nfs/rpcv2.h> 35 #include <nfs/nfsv2.h> 36 #include <nfs/nfs.h> 37 #include <nfs/nfsrvcache.h> 38 #include <nfs/nqnfs.h> 39 40 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ; 41 42 #define NFSRCHASH(xid) \ 43 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 44 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 45 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 46 u_long nfsrvhash; 47 48 #define TRUE 1 49 #define FALSE 0 50 51 #define NETFAMILY(rp) \ 52 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO) 53 54 /* 55 * Static array that defines which nfs rpc's are nonidempotent 56 */ 57 int nonidempotent[NFS_NPROCS] = { 58 FALSE, 59 FALSE, 60 TRUE, 61 FALSE, 62 FALSE, 63 FALSE, 64 FALSE, 65 FALSE, 66 TRUE, 67 TRUE, 68 TRUE, 69 TRUE, 70 TRUE, 71 TRUE, 72 TRUE, 73 TRUE, 74 FALSE, 75 FALSE, 76 FALSE, 77 FALSE, 78 FALSE, 79 FALSE, 80 FALSE, 81 }; 82 83 /* True iff the rpc reply is an nfs status ONLY! */ 84 static int repliesstatus[NFS_NPROCS] = { 85 FALSE, 86 FALSE, 87 FALSE, 88 FALSE, 89 FALSE, 90 FALSE, 91 FALSE, 92 FALSE, 93 FALSE, 94 FALSE, 95 TRUE, 96 TRUE, 97 TRUE, 98 TRUE, 99 FALSE, 100 TRUE, 101 FALSE, 102 FALSE, 103 FALSE, 104 FALSE, 105 FALSE, 106 FALSE, 107 TRUE, 108 }; 109 110 /* 111 * Initialize the server request cache list 112 */ 113 nfsrv_initcache() 114 { 115 116 nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, &nfsrvhash); 117 TAILQ_INIT(&nfsrvlruhead); 118 } 119 120 /* 121 * Look for the request in the cache 122 * If found then 123 * return action and optionally reply 124 * else 125 * insert it in the cache 126 * 127 * The rules are as follows: 128 * - if in progress, return DROP request 129 * - if completed within DELAY of the current time, return DROP it 130 * - if completed a longer time ago return REPLY if the reply was cached or 131 * return DOIT 132 * Update/add new request at end of lru list 133 */ 134 nfsrv_getcache(nam, nd, repp) 135 struct mbuf *nam; 136 register struct nfsd *nd; 137 struct mbuf **repp; 138 { 139 register struct nfsrvcache *rp; 140 struct mbuf *mb; 141 struct sockaddr_in *saddr; 142 caddr_t bpos; 143 int ret; 144 145 if (nd->nd_nqlflag != NQL_NOVAL) 146 return (RC_DOIT); 147 loop: 148 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0; 149 rp = rp->rc_hash.le_next) { 150 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 151 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nam)) { 152 if ((rp->rc_flag & RC_LOCKED) != 0) { 153 rp->rc_flag |= RC_WANTED; 154 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0); 155 goto loop; 156 } 157 rp->rc_flag |= RC_LOCKED; 158 /* If not at end of LRU chain, move it there */ 159 if (rp->rc_lru.tqe_next) { 160 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 161 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 162 } 163 if (rp->rc_state == RC_UNUSED) 164 panic("nfsrv cache"); 165 if (rp->rc_state == RC_INPROG) { 166 nfsstats.srvcache_inproghits++; 167 ret = RC_DROPIT; 168 } else if (rp->rc_flag & RC_REPSTATUS) { 169 nfsstats.srvcache_nonidemdonehits++; 170 nfs_rephead(0, nd, rp->rc_status, 171 0, (u_quad_t *)0, repp, &mb, &bpos); 172 ret = RC_REPLY; 173 } else if (rp->rc_flag & RC_REPMBUF) { 174 nfsstats.srvcache_nonidemdonehits++; 175 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, 176 M_WAIT); 177 ret = RC_REPLY; 178 } else { 179 nfsstats.srvcache_idemdonehits++; 180 rp->rc_state = RC_INPROG; 181 ret = RC_DOIT; 182 } 183 rp->rc_flag &= ~RC_LOCKED; 184 if (rp->rc_flag & RC_WANTED) { 185 rp->rc_flag &= ~RC_WANTED; 186 wakeup((caddr_t)rp); 187 } 188 return (ret); 189 } 190 } 191 nfsstats.srvcache_misses++; 192 if (numnfsrvcache < desirednfsrvcache) { 193 rp = (struct nfsrvcache *)malloc((u_long)sizeof *rp, 194 M_NFSD, M_WAITOK); 195 bzero((char *)rp, sizeof *rp); 196 numnfsrvcache++; 197 rp->rc_flag = RC_LOCKED; 198 } else { 199 rp = nfsrvlruhead.tqh_first; 200 while ((rp->rc_flag & RC_LOCKED) != 0) { 201 rp->rc_flag |= RC_WANTED; 202 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0); 203 rp = nfsrvlruhead.tqh_first; 204 } 205 rp->rc_flag |= RC_LOCKED; 206 LIST_REMOVE(rp, rc_hash); 207 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 208 if (rp->rc_flag & RC_REPMBUF) 209 m_freem(rp->rc_reply); 210 if (rp->rc_flag & RC_NAM) 211 MFREE(rp->rc_nam, mb); 212 rp->rc_flag &= (RC_LOCKED | RC_WANTED); 213 } 214 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 215 rp->rc_state = RC_INPROG; 216 rp->rc_xid = nd->nd_retxid; 217 saddr = mtod(nam, struct sockaddr_in *); 218 switch (saddr->sin_family) { 219 case AF_INET: 220 rp->rc_flag |= RC_INETADDR; 221 rp->rc_inetaddr = saddr->sin_addr.s_addr; 222 break; 223 case AF_ISO: 224 default: 225 rp->rc_flag |= RC_NAM; 226 rp->rc_nam = m_copym(nam, 0, M_COPYALL, M_WAIT); 227 break; 228 }; 229 rp->rc_proc = nd->nd_procnum; 230 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash); 231 rp->rc_flag &= ~RC_LOCKED; 232 if (rp->rc_flag & RC_WANTED) { 233 rp->rc_flag &= ~RC_WANTED; 234 wakeup((caddr_t)rp); 235 } 236 return (RC_DOIT); 237 } 238 239 /* 240 * Update a request cache entry after the rpc has been done 241 */ 242 void 243 nfsrv_updatecache(nam, nd, repvalid, repmbuf) 244 struct mbuf *nam; 245 register struct nfsd *nd; 246 int repvalid; 247 struct mbuf *repmbuf; 248 { 249 register struct nfsrvcache *rp; 250 251 if (nd->nd_nqlflag != NQL_NOVAL) 252 return; 253 loop: 254 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0; 255 rp = rp->rc_hash.le_next) { 256 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 257 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nam)) { 258 if ((rp->rc_flag & RC_LOCKED) != 0) { 259 rp->rc_flag |= RC_WANTED; 260 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0); 261 goto loop; 262 } 263 rp->rc_flag |= RC_LOCKED; 264 rp->rc_state = RC_DONE; 265 /* 266 * If we have a valid reply update status and save 267 * the reply for non-idempotent rpc's. 268 */ 269 if (repvalid && nonidempotent[nd->nd_procnum]) { 270 if (repliesstatus[nd->nd_procnum]) { 271 rp->rc_status = nd->nd_repstat; 272 rp->rc_flag |= RC_REPSTATUS; 273 } else { 274 rp->rc_reply = m_copym(repmbuf, 275 0, M_COPYALL, M_WAIT); 276 rp->rc_flag |= RC_REPMBUF; 277 } 278 } 279 rp->rc_flag &= ~RC_LOCKED; 280 if (rp->rc_flag & RC_WANTED) { 281 rp->rc_flag &= ~RC_WANTED; 282 wakeup((caddr_t)rp); 283 } 284 return; 285 } 286 } 287 } 288 289 /* 290 * Clean out the cache. Called when the last nfsd terminates. 291 */ 292 void 293 nfsrv_cleancache() 294 { 295 register struct nfsrvcache *rp, *nextrp; 296 297 for (rp = nfsrvlruhead.tqh_first; rp != 0; rp = nextrp) { 298 nextrp = rp->rc_lru.tqe_next; 299 LIST_REMOVE(rp, rc_hash); 300 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 301 free(rp, M_NFSD); 302 } 303 numnfsrvcache = 0; 304 } 305