1 /* $OpenBSD: nfs_srvcache.c,v 1.21 2008/12/24 02:43:52 thib Exp $ */ 2 /* $NetBSD: nfs_srvcache.c,v 1.12 1996/02/18 11:53:49 fvdl Exp $ */ 3 4 /* 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Rick Macklem at The University of Guelph. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95 36 */ 37 38 /* 39 * Reference: Chet Juszczak, "Improving the Performance and Correctness 40 * of an NFS Server", in Proc. Winter 1989 USENIX Conference, 41 * pages 53-63. San Diego, February 1989. 42 */ 43 #include <sys/param.h> 44 #include <sys/mount.h> 45 #include <sys/kernel.h> 46 #include <sys/systm.h> 47 #include <sys/proc.h> 48 #include <sys/mbuf.h> 49 #include <sys/malloc.h> 50 #include <sys/socket.h> 51 #include <sys/queue.h> 52 53 #include <netinet/in.h> 54 #include <nfs/rpcv2.h> 55 #include <nfs/nfsproto.h> 56 #include <nfs/nfs.h> 57 #include <nfs/nfsrvcache.h> 58 #include <nfs/nfs_var.h> 59 60 extern struct nfsstats nfsstats; 61 extern int nfsv2_procid[NFS_NPROCS]; 62 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ; 63 64 struct nfsrvcache *nfsrv_lookupcache(struct nfsrv_descript *); 65 66 #define NFSRCHASH(xid) \ 67 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 68 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 69 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 70 u_long nfsrvhash; 71 72 #define NETFAMILY(rp) \ 73 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_UNSPEC) 74 75 /* Array that defines which nfs rpc's are nonidempotent */ 76 int nonidempotent[NFS_NPROCS] = { 77 0, 0, 1, 0, 0, 0, 0, 1, 78 1, 1, 1, 1, 1, 1, 1, 1, 79 0, 0, 0, 0, 0, 0, 0, 0, 80 0, 0 81 }; 82 83 /* True iff the rpc reply is an nfs status ONLY! */ 84 int nfsv2_repstat[NFS_NPROCS] = { 85 0, 0, 0, 0, 0, 0, 0, 0, 86 0, 0, 1, 1, 1, 1, 0, 1, 87 0, 0 88 }; 89 90 /* Initialize the server request cache list */ 91 void 92 nfsrv_initcache(void) 93 { 94 95 nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, M_WAITOK, &nfsrvhash); 96 TAILQ_INIT(&nfsrvlruhead); 97 } 98 99 /* 100 * Look for the request in the cache 101 * If found then 102 * return action and optionally reply 103 * else 104 * insert it in the cache 105 * 106 * The rules are as follows: 107 * - if in progress, return DROP request 108 * - if completed within DELAY of the current time, return DROP it 109 * - if completed a longer time ago return REPLY if the reply was cached or 110 * return DOIT 111 * Update/add new request at end of lru list 112 */ 113 int 114 nfsrv_getcache(struct nfsrv_descript *nd, struct nfssvc_sock *slp, 115 struct mbuf **repp) 116 { 117 struct nfsrvcache *rp; 118 struct mbuf *mb; 119 struct sockaddr_in *saddr; 120 int ret; 121 122 /* 123 * Don't cache recent requests for reliable transport protocols. 124 * (Maybe we should for the case of a reconnect, but..) 125 */ 126 if (!nd->nd_nam2) 127 return (RC_DOIT); 128 129 rp = nfsrv_lookupcache(nd); 130 if (rp) { 131 /* If not at end of LRU chain, move it there */ 132 if (TAILQ_NEXT(rp, rc_lru)) { 133 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 134 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 135 } 136 if (rp->rc_state == RC_UNUSED) 137 panic("nfsrv cache"); 138 if (rp->rc_state == RC_INPROG) { 139 nfsstats.srvcache_inproghits++; 140 ret = RC_DROPIT; 141 } else if (rp->rc_flag & RC_REPSTATUS) { 142 nfsstats.srvcache_nonidemdonehits++; 143 nfs_rephead(0, nd, slp, rp->rc_status, repp, &mb); 144 ret = RC_REPLY; 145 } else if (rp->rc_flag & RC_REPMBUF) { 146 nfsstats.srvcache_nonidemdonehits++; 147 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, M_WAIT); 148 ret = RC_REPLY; 149 } else { 150 nfsstats.srvcache_idemdonehits++; 151 rp->rc_state = RC_INPROG; 152 ret = RC_DOIT; 153 } 154 rp->rc_flag &= ~RC_LOCKED; 155 if (rp->rc_flag & RC_WANTED) { 156 rp->rc_flag &= ~RC_WANTED; 157 wakeup(rp); 158 } 159 return (ret); 160 } 161 162 nfsstats.srvcache_misses++; 163 if (numnfsrvcache < desirednfsrvcache) { 164 rp = malloc(sizeof(*rp), M_NFSD, M_WAITOK|M_ZERO); 165 numnfsrvcache++; 166 rp->rc_flag = RC_LOCKED; 167 } else { 168 rp = TAILQ_FIRST(&nfsrvlruhead); 169 while ((rp->rc_flag & RC_LOCKED) != 0) { 170 rp->rc_flag |= RC_WANTED; 171 tsleep(rp, PZERO-1, "nfsrc", 0); 172 rp = TAILQ_FIRST(&nfsrvlruhead); 173 } 174 rp->rc_flag |= RC_LOCKED; 175 LIST_REMOVE(rp, rc_hash); 176 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 177 if (rp->rc_flag & RC_REPMBUF) 178 m_freem(rp->rc_reply); 179 if (rp->rc_flag & RC_NAM) 180 m_freem(rp->rc_nam); 181 rp->rc_flag &= (RC_LOCKED | RC_WANTED); 182 } 183 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 184 rp->rc_state = RC_INPROG; 185 rp->rc_xid = nd->nd_retxid; 186 saddr = mtod(nd->nd_nam, struct sockaddr_in *); 187 switch (saddr->sin_family) { 188 case AF_INET: 189 rp->rc_flag |= RC_INETADDR; 190 rp->rc_inetaddr = saddr->sin_addr.s_addr; 191 break; 192 default: 193 rp->rc_flag |= RC_NAM; 194 rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT); 195 break; 196 }; 197 rp->rc_proc = nd->nd_procnum; 198 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash); 199 rp->rc_flag &= ~RC_LOCKED; 200 if (rp->rc_flag & RC_WANTED) { 201 rp->rc_flag &= ~RC_WANTED; 202 wakeup(rp); 203 } 204 return (RC_DOIT); 205 } 206 207 /* Update a request cache entry after the rpc has been done */ 208 void 209 nfsrv_updatecache(struct nfsrv_descript *nd, int repvalid, 210 struct mbuf *repmbuf) 211 { 212 struct nfsrvcache *rp; 213 214 if (!nd->nd_nam2) 215 return; 216 217 rp = nfsrv_lookupcache(nd); 218 if (rp) { 219 rp->rc_state = RC_DONE; 220 /* 221 * If we have a valid reply update status and save 222 * the reply for non-idempotent rpc's. 223 */ 224 if (repvalid && nonidempotent[nd->nd_procnum]) { 225 if ((nd->nd_flag & ND_NFSV3) == 0 && 226 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) { 227 rp->rc_status = nd->nd_repstat; 228 rp->rc_flag |= RC_REPSTATUS; 229 } else { 230 rp->rc_reply = m_copym(repmbuf, 0, M_COPYALL, 231 M_WAIT); 232 rp->rc_flag |= RC_REPMBUF; 233 } 234 } 235 rp->rc_flag &= ~RC_LOCKED; 236 if (rp->rc_flag & RC_WANTED) { 237 rp->rc_flag &= ~RC_WANTED; 238 wakeup(rp); 239 } 240 return; 241 } 242 } 243 244 /* Clean out the cache. Called when the last nfsd terminates. */ 245 void 246 nfsrv_cleancache(void) 247 { 248 struct nfsrvcache *rp, *nextrp; 249 250 for (rp = TAILQ_FIRST(&nfsrvlruhead); rp != NULL; rp = nextrp) { 251 nextrp = TAILQ_NEXT(rp, rc_lru); 252 LIST_REMOVE(rp, rc_hash); 253 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 254 if (rp->rc_flag & RC_REPMBUF) 255 m_freem(rp->rc_reply); 256 if (rp->rc_flag & RC_NAM) 257 m_freem(rp->rc_nam); 258 free(rp, M_NFSD); 259 } 260 numnfsrvcache = 0; 261 } 262 263 struct nfsrvcache * 264 nfsrv_lookupcache(struct nfsrv_descript *nd) 265 { 266 struct nfsrvcache *rp; 267 268 loop: 269 LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) { 270 if (nd->nd_retxid == rp->rc_xid && 271 nd->nd_procnum == rp->rc_proc && 272 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 273 if ((rp->rc_flag & RC_LOCKED)) { 274 rp->rc_flag |= RC_WANTED; 275 tsleep(rp, PZERO - 1, "nfsrc", 0); 276 goto loop; 277 } 278 rp->rc_flag |= RC_LOCKED; 279 return (rp); 280 } 281 } 282 283 return (NULL); 284 } 285