1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * 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 7.20 (Berkeley) 03/02/93 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) (((xid) + ((xid) >> 16)) & rheadhash) 43 static struct nfsrvcache *nfsrvlruhead, **nfsrvlrutail = &nfsrvlruhead; 44 static struct nfsrvcache **rheadhtbl; 45 static u_long rheadhash; 46 47 #define TRUE 1 48 #define FALSE 0 49 50 #define NETFAMILY(rp) \ 51 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO) 52 53 /* 54 * Static array that defines which nfs rpc's are nonidempotent 55 */ 56 int nonidempotent[NFS_NPROCS] = { 57 FALSE, 58 FALSE, 59 TRUE, 60 FALSE, 61 FALSE, 62 FALSE, 63 FALSE, 64 FALSE, 65 TRUE, 66 TRUE, 67 TRUE, 68 TRUE, 69 TRUE, 70 TRUE, 71 TRUE, 72 TRUE, 73 FALSE, 74 FALSE, 75 FALSE, 76 FALSE, 77 FALSE, 78 FALSE, 79 FALSE, 80 }; 81 82 /* True iff the rpc reply is an nfs status ONLY! */ 83 static int repliesstatus[NFS_NPROCS] = { 84 FALSE, 85 FALSE, 86 FALSE, 87 FALSE, 88 FALSE, 89 FALSE, 90 FALSE, 91 FALSE, 92 FALSE, 93 FALSE, 94 TRUE, 95 TRUE, 96 TRUE, 97 TRUE, 98 FALSE, 99 TRUE, 100 FALSE, 101 FALSE, 102 FALSE, 103 FALSE, 104 FALSE, 105 FALSE, 106 TRUE, 107 }; 108 109 /* 110 * Initialize the server request cache list 111 */ 112 nfsrv_initcache() 113 { 114 115 rheadhtbl = hashinit(desirednfsrvcache, M_NFSD, &rheadhash); 116 } 117 118 /* 119 * Look for the request in the cache 120 * If found then 121 * return action and optionally reply 122 * else 123 * insert it in the cache 124 * 125 * The rules are as follows: 126 * - if in progress, return DROP request 127 * - if completed within DELAY of the current time, return DROP it 128 * - if completed a longer time ago return REPLY if the reply was cached or 129 * return DOIT 130 * Update/add new request at end of lru list 131 */ 132 nfsrv_getcache(nam, nd, repp) 133 struct mbuf *nam; 134 register struct nfsd *nd; 135 struct mbuf **repp; 136 { 137 register struct nfsrvcache *rp, *rq, **rpp; 138 struct mbuf *mb; 139 struct sockaddr_in *saddr; 140 caddr_t bpos; 141 int ret; 142 143 if (nd->nd_nqlflag != NQL_NOVAL) 144 return (RC_DOIT); 145 rpp = &rheadhtbl[NFSRCHASH(nd->nd_retxid)]; 146 loop: 147 for (rp = *rpp; rp; rp = rp->rc_forw) { 148 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 149 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nam)) { 150 if ((rp->rc_flag & RC_LOCKED) != 0) { 151 rp->rc_flag |= RC_WANTED; 152 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0); 153 goto loop; 154 } 155 rp->rc_flag |= RC_LOCKED; 156 /* If not at end of LRU chain, move it there */ 157 if (rp->rc_next) { 158 /* remove from LRU chain */ 159 *rp->rc_prev = rp->rc_next; 160 rp->rc_next->rc_prev = rp->rc_prev; 161 /* and replace at end of it */ 162 rp->rc_next = NULL; 163 rp->rc_prev = nfsrvlrutail; 164 *nfsrvlrutail = rp; 165 nfsrvlrutail = &rp->rc_next; 166 } 167 if (rp->rc_state == RC_UNUSED) 168 panic("nfsrv cache"); 169 if (rp->rc_state == RC_INPROG || 170 (time.tv_sec - rp->rc_timestamp) < RC_DELAY) { 171 nfsstats.srvcache_inproghits++; 172 ret = RC_DROPIT; 173 } else if (rp->rc_flag & RC_REPSTATUS) { 174 nfsstats.srvcache_idemdonehits++; 175 nfs_rephead(0, nd, rp->rc_status, 176 0, (u_quad_t *)0, repp, &mb, &bpos); 177 rp->rc_timestamp = time.tv_sec; 178 ret = RC_REPLY; 179 } else if (rp->rc_flag & RC_REPMBUF) { 180 nfsstats.srvcache_idemdonehits++; 181 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, 182 M_WAIT); 183 rp->rc_timestamp = time.tv_sec; 184 ret = RC_REPLY; 185 } else { 186 nfsstats.srvcache_nonidemdonehits++; 187 rp->rc_state = RC_INPROG; 188 ret = RC_DOIT; 189 } 190 rp->rc_flag &= ~RC_LOCKED; 191 if (rp->rc_flag & RC_WANTED) { 192 rp->rc_flag &= ~RC_WANTED; 193 wakeup((caddr_t)rp); 194 } 195 return (ret); 196 } 197 } 198 nfsstats.srvcache_misses++; 199 if (numnfsrvcache < desirednfsrvcache) { 200 rp = (struct nfsrvcache *)malloc((u_long)sizeof *rp, 201 M_NFSD, M_WAITOK); 202 bzero((char *)rp, sizeof *rp); 203 numnfsrvcache++; 204 rp->rc_flag = RC_LOCKED; 205 } else { 206 rp = nfsrvlruhead; 207 while ((rp->rc_flag & RC_LOCKED) != 0) { 208 rp->rc_flag |= RC_WANTED; 209 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0); 210 rp = nfsrvlruhead; 211 } 212 rp->rc_flag |= RC_LOCKED; 213 /* remove from hash chain */ 214 if (rq = rp->rc_forw) 215 rq->rc_back = rp->rc_back; 216 *rp->rc_back = rq; 217 /* remove from LRU chain */ 218 *rp->rc_prev = rp->rc_next; 219 rp->rc_next->rc_prev = rp->rc_prev; 220 if (rp->rc_flag & RC_REPMBUF) 221 m_freem(rp->rc_reply); 222 if (rp->rc_flag & RC_NAM) 223 MFREE(rp->rc_nam, mb); 224 rp->rc_flag &= (RC_LOCKED | RC_WANTED); 225 } 226 /* place at end of LRU list */ 227 rp->rc_next = NULL; 228 rp->rc_prev = nfsrvlrutail; 229 *nfsrvlrutail = rp; 230 nfsrvlrutail = &rp->rc_next; 231 rp->rc_state = RC_INPROG; 232 rp->rc_xid = nd->nd_retxid; 233 saddr = mtod(nam, struct sockaddr_in *); 234 switch (saddr->sin_family) { 235 case AF_INET: 236 rp->rc_flag |= RC_INETADDR; 237 rp->rc_inetaddr = saddr->sin_addr.s_addr; 238 break; 239 case AF_ISO: 240 default: 241 rp->rc_flag |= RC_NAM; 242 rp->rc_nam = m_copym(nam, 0, M_COPYALL, M_WAIT); 243 break; 244 }; 245 rp->rc_proc = nd->nd_procnum; 246 /* insert into hash chain */ 247 if (rq = *rpp) 248 rq->rc_back = &rp->rc_forw; 249 rp->rc_forw = rq; 250 rp->rc_back = rpp; 251 *rpp = rp; 252 rp->rc_flag &= ~RC_LOCKED; 253 if (rp->rc_flag & RC_WANTED) { 254 rp->rc_flag &= ~RC_WANTED; 255 wakeup((caddr_t)rp); 256 } 257 return (RC_DOIT); 258 } 259 260 /* 261 * Update a request cache entry after the rpc has been done 262 */ 263 void 264 nfsrv_updatecache(nam, nd, repvalid, repmbuf) 265 struct mbuf *nam; 266 register struct nfsd *nd; 267 int repvalid; 268 struct mbuf *repmbuf; 269 { 270 register struct nfsrvcache *rp; 271 272 if (nd->nd_nqlflag != NQL_NOVAL) 273 return; 274 loop: 275 for (rp = rheadhtbl[NFSRCHASH(nd->nd_retxid)]; rp; rp = rp->rc_forw) { 276 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 277 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nam)) { 278 if ((rp->rc_flag & RC_LOCKED) != 0) { 279 rp->rc_flag |= RC_WANTED; 280 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0); 281 goto loop; 282 } 283 rp->rc_flag |= RC_LOCKED; 284 rp->rc_state = RC_DONE; 285 /* 286 * If we have a valid reply update status and save 287 * the reply for non-idempotent rpc's. 288 * Otherwise invalidate entry by setting the timestamp 289 * to nil. 290 */ 291 if (repvalid) { 292 rp->rc_timestamp = time.tv_sec; 293 if (nonidempotent[nd->nd_procnum]) { 294 if (repliesstatus[nd->nd_procnum]) { 295 rp->rc_status = nd->nd_repstat; 296 rp->rc_flag |= RC_REPSTATUS; 297 } else { 298 rp->rc_reply = m_copym(repmbuf, 299 0, M_COPYALL, M_WAIT); 300 rp->rc_flag |= RC_REPMBUF; 301 } 302 } 303 } else { 304 rp->rc_timestamp = 0; 305 } 306 rp->rc_flag &= ~RC_LOCKED; 307 if (rp->rc_flag & RC_WANTED) { 308 rp->rc_flag &= ~RC_WANTED; 309 wakeup((caddr_t)rp); 310 } 311 return; 312 } 313 } 314 } 315 316 /* 317 * Clean out the cache. Called when the last nfsd terminates. 318 */ 319 void 320 nfsrv_cleancache() 321 { 322 register struct nfsrvcache *rp, *nextrp; 323 324 for (rp = nfsrvlruhead; rp; rp = nextrp) { 325 nextrp = rp->rc_next; 326 free(rp, M_NFSD); 327 } 328 bzero((char *)rheadhtbl, (rheadhash + 1) * sizeof(void *)); 329 nfsrvlruhead = NULL; 330 nfsrvlrutail = &nfsrvlruhead; 331 numnfsrvcache = 0; 332 } 333