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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95 33 * $FreeBSD: src/sys/nfs/nfs_srvcache.c,v 1.21 2000/02/13 03:32:06 peter Exp $ 34 */ 35 36 /* 37 * Reference: Chet Juszczak, "Improving the Performance and Correctness 38 * of an NFS Server", in Proc. Winter 1989 USENIX Conference, 39 * pages 53-63. San Diego, February 1989. 40 */ 41 #include <sys/param.h> 42 #include <sys/malloc.h> 43 #include <sys/mount.h> 44 #include <sys/systm.h> 45 #include <sys/mbuf.h> 46 #include <sys/socket.h> 47 #include <sys/socketvar.h> /* for dup_sockaddr */ 48 49 #include <netinet/in.h> 50 #include "rpcv2.h" 51 #include "nfsproto.h" 52 #include "nfs.h" 53 #include "nfsrvcache.h" 54 55 #ifndef NFS_NOSERVER 56 static long numnfsrvcache; 57 static long desirednfsrvcache; 58 59 #define NFSRCHASH(xid) \ 60 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 61 static LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 62 static TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 63 static u_long nfsrvhash; 64 65 #define TRUE 1 66 #define FALSE 0 67 68 #define NETFAMILY(rp) \ 69 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO) 70 71 struct lwkt_token srvcache_token = LWKT_TOKEN_INITIALIZER(srvcache_token); 72 73 /* 74 * Static array that defines which nfs rpc's are nonidempotent 75 */ 76 static int nonidempotent[NFS_NPROCS] = { 77 FALSE, 78 FALSE, 79 TRUE, 80 FALSE, 81 FALSE, 82 FALSE, 83 FALSE, 84 TRUE, 85 TRUE, 86 TRUE, 87 TRUE, 88 TRUE, 89 TRUE, 90 TRUE, 91 TRUE, 92 TRUE, 93 FALSE, 94 FALSE, 95 FALSE, 96 FALSE, 97 FALSE, 98 FALSE, 99 FALSE, 100 FALSE, 101 FALSE, 102 FALSE, 103 }; 104 105 /* True iff the rpc reply is an nfs status ONLY! */ 106 static int nfsv2_repstat[NFS_NPROCS] = { 107 FALSE, 108 FALSE, 109 FALSE, 110 FALSE, 111 FALSE, 112 FALSE, 113 FALSE, 114 FALSE, 115 FALSE, 116 FALSE, 117 TRUE, 118 TRUE, 119 TRUE, 120 TRUE, 121 FALSE, 122 TRUE, 123 FALSE, 124 FALSE, 125 }; 126 127 /* 128 * Size the NFS server's duplicate request cache at 1/2 the nmbclusters, 129 * within a (64, 2048) range. This is to prevent all mbuf clusters being 130 * tied up in the NFS dupreq cache for small values of nmbclusters. 131 */ 132 static void 133 nfsrvcache_size_change(void) 134 { 135 desirednfsrvcache = nmbclusters / 2; 136 desirednfsrvcache = MIN(desirednfsrvcache, NFSRVCACHE_MAX_SIZE); 137 desirednfsrvcache = MAX(desirednfsrvcache, NFSRVCACHE_MIN_SIZE); 138 } 139 140 /* 141 * Initialize the server request cache list 142 */ 143 void 144 nfsrv_initcache(void) 145 { 146 nfsrvcache_size_change(); 147 nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, &nfsrvhash); 148 TAILQ_INIT(&nfsrvlruhead); 149 } 150 151 /* 152 * Look for the request in the cache 153 * If found then 154 * return action and optionally reply 155 * else 156 * insert it in the cache 157 * 158 * The rules are as follows: 159 * - if in progress, return DROP request 160 * - if completed within DELAY of the current time, return DROP it 161 * - if completed a longer time ago return REPLY if the reply was cached or 162 * return DOIT 163 * Update/add new request at end of lru list 164 */ 165 int 166 nfsrv_getcache(struct nfsrv_descript *nd, struct nfssvc_sock *slp, 167 struct mbuf **repp) 168 { 169 struct nfsrvcache *rp; 170 struct mbuf *mb; 171 struct sockaddr_in *saddr; 172 caddr_t bpos; 173 int ret; 174 175 /* 176 * Don't cache recent requests for reliable transport protocols. 177 * (Maybe we should for the case of a reconnect, but..) 178 */ 179 if (!nd->nd_nam2) 180 return (RC_DOIT); 181 182 lwkt_gettoken(&srvcache_token); 183 loop: 184 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != NULL; 185 rp = rp->rc_hash.le_next) { 186 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 187 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 188 NFS_DPF(RC, ("H%03x", rp->rc_xid & 0xfff)); 189 if ((rp->rc_flag & RC_LOCKED) != 0) { 190 rp->rc_flag |= RC_WANTED; 191 tsleep((caddr_t)rp, 0, "nfsrc", 0); 192 goto loop; 193 } 194 rp->rc_flag |= RC_LOCKED; 195 /* If not at end of LRU chain, move it there */ 196 if (TAILQ_NEXT(rp, rc_lru) != NULL) { 197 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 198 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 199 } 200 if (rp->rc_state == RC_UNUSED) 201 panic("nfsrv cache"); 202 if (rp->rc_state == RC_INPROG) { 203 nfsstats.srvcache_inproghits++; 204 ret = RC_DROPIT; 205 } else if (rp->rc_flag & RC_REPSTATUS) { 206 nfsstats.srvcache_nonidemdonehits++; 207 nfs_rephead(0, nd, slp, rp->rc_status, 208 repp, &mb, &bpos); 209 ret = RC_REPLY; 210 } else if (rp->rc_flag & RC_REPMBUF) { 211 nfsstats.srvcache_nonidemdonehits++; 212 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, 213 MB_WAIT); 214 ret = RC_REPLY; 215 } else { 216 nfsstats.srvcache_idemdonehits++; 217 rp->rc_state = RC_INPROG; 218 ret = RC_DOIT; 219 } 220 rp->rc_flag &= ~RC_LOCKED; 221 if (rp->rc_flag & RC_WANTED) { 222 rp->rc_flag &= ~RC_WANTED; 223 wakeup((caddr_t)rp); 224 } 225 lwkt_reltoken(&srvcache_token); 226 return (ret); 227 } 228 } 229 230 nfsstats.srvcache_misses++; 231 NFS_DPF(RC, ("M%03x", nd->nd_retxid & 0xfff)); 232 if (numnfsrvcache < desirednfsrvcache) { 233 rp = kmalloc((u_long)sizeof *rp, M_NFSD, M_WAITOK | M_ZERO); 234 numnfsrvcache++; 235 rp->rc_flag = RC_LOCKED; 236 } else { 237 rp = TAILQ_FIRST(&nfsrvlruhead); 238 while ((rp->rc_flag & RC_LOCKED) != 0) { 239 rp->rc_flag |= RC_WANTED; 240 tsleep((caddr_t)rp, 0, "nfsrc", 0); 241 rp = TAILQ_FIRST(&nfsrvlruhead); 242 } 243 rp->rc_flag |= RC_LOCKED; 244 LIST_REMOVE(rp, rc_hash); 245 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 246 if (rp->rc_flag & RC_REPMBUF) { 247 m_freem(rp->rc_reply); 248 rp->rc_reply = NULL; 249 rp->rc_flag &= ~RC_REPMBUF; 250 } 251 if (rp->rc_flag & RC_NAM) { 252 kfree(rp->rc_nam, M_SONAME); 253 rp->rc_nam = NULL; 254 rp->rc_flag &= ~RC_NAM; 255 } 256 } 257 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 258 259 rp->rc_state = RC_INPROG; 260 rp->rc_xid = nd->nd_retxid; 261 saddr = (struct sockaddr_in *)nd->nd_nam; 262 switch (saddr->sin_family) { 263 case AF_INET: 264 rp->rc_flag |= RC_INETADDR; 265 rp->rc_inetaddr = saddr->sin_addr.s_addr; 266 break; 267 case AF_ISO: 268 default: 269 rp->rc_flag |= RC_NAM; 270 rp->rc_nam = dup_sockaddr(nd->nd_nam); 271 break; 272 } 273 rp->rc_proc = nd->nd_procnum; 274 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash); 275 rp->rc_flag &= ~RC_LOCKED; 276 if (rp->rc_flag & RC_WANTED) { 277 rp->rc_flag &= ~RC_WANTED; 278 wakeup((caddr_t)rp); 279 } 280 lwkt_reltoken(&srvcache_token); 281 282 return (RC_DOIT); 283 } 284 285 /* 286 * Update a request cache entry after the rpc has been done 287 */ 288 void 289 nfsrv_updatecache(struct nfsrv_descript *nd, int repvalid, struct mbuf *repmbuf) 290 { 291 struct nfsrvcache *rp; 292 293 if (!nd->nd_nam2) 294 return; 295 296 lwkt_gettoken(&srvcache_token); 297 loop: 298 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != NULL; 299 rp = rp->rc_hash.le_next) { 300 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc && 301 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 302 NFS_DPF(RC, ("U%03x", rp->rc_xid & 0xfff)); 303 if ((rp->rc_flag & RC_LOCKED) != 0) { 304 rp->rc_flag |= RC_WANTED; 305 tsleep((caddr_t)rp, 0, "nfsrc", 0); 306 goto loop; 307 } 308 rp->rc_flag |= RC_LOCKED; 309 if (rp->rc_state == RC_DONE) { 310 /* 311 * This can occur if the cache is too small. 312 * Retransmits of the same request aren't 313 * dropped so we may see the operation 314 * complete more then once. 315 */ 316 if (rp->rc_flag & RC_REPMBUF) { 317 m_freem(rp->rc_reply); 318 rp->rc_reply = NULL; 319 rp->rc_flag &= ~RC_REPMBUF; 320 } 321 } 322 rp->rc_state = RC_DONE; 323 324 /* 325 * If we have a valid reply update status and save 326 * the reply for non-idempotent rpc's. 327 */ 328 if (repvalid && nonidempotent[nd->nd_procnum]) { 329 if ((nd->nd_flag & ND_NFSV3) == 0 && 330 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) { 331 rp->rc_status = nd->nd_repstat; 332 rp->rc_flag |= RC_REPSTATUS; 333 } else { 334 if (rp->rc_flag & RC_REPMBUF) { 335 m_freem(rp->rc_reply); 336 rp->rc_reply = NULL; 337 rp->rc_flag &= ~RC_REPMBUF; 338 } 339 rp->rc_reply = m_copym(repmbuf, 0, 340 M_COPYALL, MB_WAIT); 341 rp->rc_flag |= RC_REPMBUF; 342 } 343 } 344 rp->rc_flag &= ~RC_LOCKED; 345 if (rp->rc_flag & RC_WANTED) { 346 rp->rc_flag &= ~RC_WANTED; 347 wakeup((caddr_t)rp); 348 } 349 break; 350 } 351 } 352 lwkt_reltoken(&srvcache_token); 353 NFS_DPF(RC, ("L%03x", nd->nd_retxid & 0xfff)); 354 } 355 356 /* 357 * Clean out the cache. Called when the last nfsd terminates. 358 */ 359 void 360 nfsrv_cleancache(void) 361 { 362 struct nfsrvcache *rp; 363 364 lwkt_gettoken(&srvcache_token); 365 while ((rp = TAILQ_FIRST(&nfsrvlruhead)) != NULL) { 366 if (rp->rc_flag & RC_LOCKED) { 367 rp->rc_flag |= RC_WANTED; 368 tsleep((caddr_t)rp, 0, "nfsrc", 0); 369 continue; 370 } 371 LIST_REMOVE(rp, rc_hash); 372 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 373 if (rp->rc_flag & RC_REPMBUF) { 374 m_freem(rp->rc_reply); 375 rp->rc_reply = NULL; 376 rp->rc_flag &= ~RC_REPMBUF; 377 } 378 if (rp->rc_flag & RC_NAM) { 379 kfree(rp->rc_nam, M_SONAME); 380 rp->rc_nam = NULL; 381 rp->rc_flag &= ~RC_NAM; 382 } 383 kfree(rp, M_NFSD); 384 } 385 numnfsrvcache = 0; 386 lwkt_reltoken(&srvcache_token); 387 } 388 389 #endif /* NFS_NOSERVER */ 390