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 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95 37 * $FreeBSD: src/sys/nfs/nfs_srvcache.c,v 1.21 2000/02/13 03:32:06 peter Exp $ 38 * $DragonFly: src/sys/vfs/nfs/nfs_srvcache.c,v 1.13 2008/01/05 14:02:41 swildner Exp $ 39 */ 40 41 /* 42 * Reference: Chet Juszczak, "Improving the Performance and Correctness 43 * of an NFS Server", in Proc. Winter 1989 USENIX Conference, 44 * pages 53-63. San Diego, February 1989. 45 */ 46 #include <sys/param.h> 47 #include <sys/malloc.h> 48 #include <sys/mount.h> 49 #include <sys/systm.h> 50 #include <sys/mbuf.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> /* for dup_sockaddr */ 53 54 #include <netinet/in.h> 55 #include "rpcv2.h" 56 #include "nfsproto.h" 57 #include "nfs.h" 58 #include "nfsrvcache.h" 59 60 #ifndef NFS_NOSERVER 61 extern struct nfsstats nfsstats; 62 extern int nfsv2_procid[NFS_NPROCS]; 63 static long numnfsrvcache; 64 static long desirednfsrvcache = NFSRVCACHESIZ; 65 66 #define NFSRCHASH(xid) \ 67 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 68 static LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 69 static TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 70 static u_long nfsrvhash; 71 72 #define TRUE 1 73 #define FALSE 0 74 75 #define NETFAMILY(rp) \ 76 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO) 77 78 /* 79 * Static array that defines which nfs rpc's are nonidempotent 80 */ 81 static int nonidempotent[NFS_NPROCS] = { 82 FALSE, 83 FALSE, 84 TRUE, 85 FALSE, 86 FALSE, 87 FALSE, 88 FALSE, 89 TRUE, 90 TRUE, 91 TRUE, 92 TRUE, 93 TRUE, 94 TRUE, 95 TRUE, 96 TRUE, 97 TRUE, 98 FALSE, 99 FALSE, 100 FALSE, 101 FALSE, 102 FALSE, 103 FALSE, 104 FALSE, 105 FALSE, 106 FALSE, 107 FALSE, 108 }; 109 110 /* True iff the rpc reply is an nfs status ONLY! */ 111 static int nfsv2_repstat[NFS_NPROCS] = { 112 FALSE, 113 FALSE, 114 FALSE, 115 FALSE, 116 FALSE, 117 FALSE, 118 FALSE, 119 FALSE, 120 FALSE, 121 FALSE, 122 TRUE, 123 TRUE, 124 TRUE, 125 TRUE, 126 FALSE, 127 TRUE, 128 FALSE, 129 FALSE, 130 }; 131 132 /* 133 * Initialize the server request cache list 134 */ 135 void 136 nfsrv_initcache(void) 137 { 138 139 nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, &nfsrvhash); 140 TAILQ_INIT(&nfsrvlruhead); 141 } 142 143 /* 144 * Look for the request in the cache 145 * If found then 146 * return action and optionally reply 147 * else 148 * insert it in the cache 149 * 150 * The rules are as follows: 151 * - if in progress, return DROP request 152 * - if completed within DELAY of the current time, return DROP it 153 * - if completed a longer time ago return REPLY if the reply was cached or 154 * return DOIT 155 * Update/add new request at end of lru list 156 */ 157 int 158 nfsrv_getcache(struct nfsrv_descript *nd, struct nfssvc_sock *slp, 159 struct mbuf **repp) 160 { 161 struct nfsrvcache *rp; 162 struct mbuf *mb; 163 struct sockaddr_in *saddr; 164 caddr_t bpos; 165 int ret; 166 167 /* 168 * Don't cache recent requests for reliable transport protocols. 169 * (Maybe we should for the case of a reconnect, but..) 170 */ 171 if (!nd->nd_nam2) 172 return (RC_DOIT); 173 loop: 174 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0; 175 rp = rp->rc_hash.le_next) { 176 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 177 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 178 NFS_DPF(RC, ("H%03x", rp->rc_xid & 0xfff)); 179 if ((rp->rc_flag & RC_LOCKED) != 0) { 180 rp->rc_flag |= RC_WANTED; 181 (void) tsleep((caddr_t)rp, 0, "nfsrc", 0); 182 goto loop; 183 } 184 rp->rc_flag |= RC_LOCKED; 185 /* If not at end of LRU chain, move it there */ 186 if (TAILQ_NEXT(rp, rc_lru) != NULL) { 187 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 188 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 189 } 190 if (rp->rc_state == RC_UNUSED) 191 panic("nfsrv cache"); 192 if (rp->rc_state == RC_INPROG) { 193 nfsstats.srvcache_inproghits++; 194 ret = RC_DROPIT; 195 } else if (rp->rc_flag & RC_REPSTATUS) { 196 nfsstats.srvcache_nonidemdonehits++; 197 nfs_rephead(0, nd, slp, rp->rc_status, 198 repp, &mb, &bpos); 199 ret = RC_REPLY; 200 } else if (rp->rc_flag & RC_REPMBUF) { 201 nfsstats.srvcache_nonidemdonehits++; 202 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, 203 MB_WAIT); 204 ret = RC_REPLY; 205 } else { 206 nfsstats.srvcache_idemdonehits++; 207 rp->rc_state = RC_INPROG; 208 ret = RC_DOIT; 209 } 210 rp->rc_flag &= ~RC_LOCKED; 211 if (rp->rc_flag & RC_WANTED) { 212 rp->rc_flag &= ~RC_WANTED; 213 wakeup((caddr_t)rp); 214 } 215 return (ret); 216 } 217 } 218 nfsstats.srvcache_misses++; 219 NFS_DPF(RC, ("M%03x", nd->nd_retxid & 0xfff)); 220 if (numnfsrvcache < desirednfsrvcache) { 221 rp = (struct nfsrvcache *)kmalloc((u_long)sizeof *rp, 222 M_NFSD, M_WAITOK | M_ZERO); 223 numnfsrvcache++; 224 rp->rc_flag = RC_LOCKED; 225 } else { 226 rp = TAILQ_FIRST(&nfsrvlruhead); 227 while ((rp->rc_flag & RC_LOCKED) != 0) { 228 rp->rc_flag |= RC_WANTED; 229 (void) tsleep((caddr_t)rp, 0, "nfsrc", 0); 230 rp = TAILQ_FIRST(&nfsrvlruhead); 231 } 232 rp->rc_flag |= RC_LOCKED; 233 LIST_REMOVE(rp, rc_hash); 234 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 235 if (rp->rc_flag & RC_REPMBUF) 236 m_freem(rp->rc_reply); 237 if (rp->rc_flag & RC_NAM) 238 FREE(rp->rc_nam, M_SONAME); 239 rp->rc_flag &= (RC_LOCKED | RC_WANTED); 240 } 241 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 242 rp->rc_state = RC_INPROG; 243 rp->rc_xid = nd->nd_retxid; 244 saddr = (struct sockaddr_in *)nd->nd_nam; 245 switch (saddr->sin_family) { 246 case AF_INET: 247 rp->rc_flag |= RC_INETADDR; 248 rp->rc_inetaddr = saddr->sin_addr.s_addr; 249 break; 250 case AF_ISO: 251 default: 252 rp->rc_flag |= RC_NAM; 253 rp->rc_nam = dup_sockaddr(nd->nd_nam); 254 break; 255 }; 256 rp->rc_proc = nd->nd_procnum; 257 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash); 258 rp->rc_flag &= ~RC_LOCKED; 259 if (rp->rc_flag & RC_WANTED) { 260 rp->rc_flag &= ~RC_WANTED; 261 wakeup((caddr_t)rp); 262 } 263 return (RC_DOIT); 264 } 265 266 /* 267 * Update a request cache entry after the rpc has been done 268 */ 269 void 270 nfsrv_updatecache(struct nfsrv_descript *nd, int repvalid, struct mbuf *repmbuf) 271 { 272 struct nfsrvcache *rp; 273 274 if (!nd->nd_nam2) 275 return; 276 loop: 277 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0; 278 rp = rp->rc_hash.le_next) { 279 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 280 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 281 NFS_DPF(RC, ("U%03x", rp->rc_xid & 0xfff)); 282 if ((rp->rc_flag & RC_LOCKED) != 0) { 283 rp->rc_flag |= RC_WANTED; 284 (void) tsleep((caddr_t)rp, 0, "nfsrc", 0); 285 goto loop; 286 } 287 rp->rc_flag |= RC_LOCKED; 288 if (rp->rc_state == RC_DONE) { 289 /* 290 * This can occur if the cache is too small. 291 * Retransmits of the same request aren't 292 * dropped so we may see the operation 293 * complete more then once. 294 */ 295 if (rp->rc_flag & RC_REPMBUF) { 296 m_freem(rp->rc_reply); 297 rp->rc_flag &= ~RC_REPMBUF; 298 } 299 } 300 rp->rc_state = RC_DONE; 301 /* 302 * If we have a valid reply update status and save 303 * the reply for non-idempotent rpc's. 304 */ 305 if (repvalid && nonidempotent[nd->nd_procnum]) { 306 if ((nd->nd_flag & ND_NFSV3) == 0 && 307 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) { 308 rp->rc_status = nd->nd_repstat; 309 rp->rc_flag |= RC_REPSTATUS; 310 } else { 311 rp->rc_reply = m_copym(repmbuf, 312 0, M_COPYALL, MB_WAIT); 313 rp->rc_flag |= RC_REPMBUF; 314 } 315 } 316 rp->rc_flag &= ~RC_LOCKED; 317 if (rp->rc_flag & RC_WANTED) { 318 rp->rc_flag &= ~RC_WANTED; 319 wakeup((caddr_t)rp); 320 } 321 return; 322 } 323 } 324 NFS_DPF(RC, ("L%03x", nd->nd_retxid & 0xfff)); 325 } 326 327 /* 328 * Clean out the cache. Called when the last nfsd terminates. 329 */ 330 void 331 nfsrv_cleancache(void) 332 { 333 struct nfsrvcache *rp, *nextrp; 334 335 TAILQ_FOREACH_MUTABLE(rp, &nfsrvlruhead, rc_lru, nextrp) { 336 LIST_REMOVE(rp, rc_hash); 337 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 338 if (rp->rc_flag & RC_REPMBUF) 339 m_freem(rp->rc_reply); 340 if (rp->rc_flag & RC_NAM) 341 kfree(rp->rc_nam, M_SONAME); 342 kfree(rp, M_NFSD); 343 } 344 numnfsrvcache = 0; 345 } 346 347 #endif /* NFS_NOSERVER */ 348