nfs_srvcache.c revision 1.42
1 /* $NetBSD: nfs_srvcache.c,v 1.42 2008/05/05 17:11:17 ad Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Rick Macklem at The University of Guelph. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95 35 */ 36 37 /* 38 * Reference: Chet Juszczak, "Improving the Performance and Correctness 39 * of an NFS Server", in Proc. Winter 1989 USENIX Conference, 40 * pages 53-63. San Diego, February 1989. 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: nfs_srvcache.c,v 1.42 2008/05/05 17:11:17 ad Exp $"); 45 46 #include "opt_iso.h" 47 48 #include <sys/param.h> 49 #include <sys/vnode.h> 50 #include <sys/condvar.h> 51 #include <sys/mount.h> 52 #include <sys/kernel.h> 53 #include <sys/systm.h> 54 #include <sys/lock.h> 55 #include <sys/proc.h> 56 #include <sys/pool.h> 57 #include <sys/mbuf.h> 58 #include <sys/mutex.h> 59 #include <sys/socket.h> 60 #include <sys/socketvar.h> 61 62 #include <netinet/in.h> 63 #ifdef ISO 64 #include <netiso/iso.h> 65 #endif 66 #include <nfs/nfsm_subs.h> 67 #include <nfs/rpcv2.h> 68 #include <nfs/nfsproto.h> 69 #include <nfs/nfs.h> 70 #include <nfs/nfsrvcache.h> 71 #include <nfs/nfs_var.h> 72 73 extern struct nfsstats nfsstats; 74 extern const int nfsv2_procid[NFS_NPROCS]; 75 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ; 76 struct pool nfs_reqcache_pool; 77 78 #define NFSRCHASH(xid) \ 79 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 80 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 81 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 82 kmutex_t nfsrv_reqcache_lock; 83 u_long nfsrvhash; 84 85 #if defined(MBUFTRACE) 86 static struct mowner nfsd_cache_mowner = MOWNER_INIT("nfsd", "cache"); 87 #endif /* defined(MBUFTRACE) */ 88 89 #define NETFAMILY(rp) \ 90 (((rp)->rc_flags & RC_INETADDR) ? AF_INET : AF_ISO) 91 92 static struct nfsrvcache *nfsrv_lookupcache(struct nfsrv_descript *nd); 93 static void nfsrv_unlockcache(struct nfsrvcache *rp); 94 95 /* 96 * Static array that defines which nfs rpc's are nonidempotent 97 */ 98 const int nonidempotent[NFS_NPROCS] = { 99 false, /* NULL */ 100 false, /* GETATTR */ 101 true, /* SETATTR */ 102 false, /* LOOKUP */ 103 false, /* ACCESS */ 104 false, /* READLINK */ 105 false, /* READ */ 106 true, /* WRITE */ 107 true, /* CREATE */ 108 true, /* MKDIR */ 109 true, /* SYMLINK */ 110 true, /* MKNOD */ 111 true, /* REMOVE */ 112 true, /* RMDIR */ 113 true, /* RENAME */ 114 true, /* LINK */ 115 false, /* READDIR */ 116 false, /* READDIRPLUS */ 117 false, /* FSSTAT */ 118 false, /* FSINFO */ 119 false, /* PATHCONF */ 120 false, /* COMMIT */ 121 false, /* NOOP */ 122 }; 123 124 /* True iff the rpc reply is an nfs status ONLY! */ 125 static const int nfsv2_repstat[NFS_NPROCS] = { 126 false, /* NULL */ 127 false, /* GETATTR */ 128 false, /* SETATTR */ 129 false, /* NOOP */ 130 false, /* LOOKUP */ 131 false, /* READLINK */ 132 false, /* READ */ 133 false, /* Obsolete WRITECACHE */ 134 false, /* WRITE */ 135 false, /* CREATE */ 136 true, /* REMOVE */ 137 true, /* RENAME */ 138 true, /* LINK */ 139 true, /* SYMLINK */ 140 false, /* MKDIR */ 141 true, /* RMDIR */ 142 false, /* READDIR */ 143 false, /* STATFS */ 144 }; 145 146 static void 147 cleanentry(struct nfsrvcache *rp) 148 { 149 150 if ((rp->rc_flags & RC_REPMBUF) != 0) { 151 m_freem(rp->rc_reply); 152 } 153 if ((rp->rc_flags & RC_NAM) != 0) { 154 m_free(rp->rc_nam); 155 } 156 rp->rc_flags &= ~(RC_REPSTATUS|RC_REPMBUF); 157 } 158 159 /* 160 * Initialize the server request cache list 161 */ 162 void 163 nfsrv_initcache() 164 { 165 166 mutex_init(&nfsrv_reqcache_lock, MUTEX_DEFAULT, IPL_NONE); 167 nfsrvhashtbl = hashinit(desirednfsrvcache, HASH_LIST, true, 168 &nfsrvhash); 169 TAILQ_INIT(&nfsrvlruhead); 170 pool_init(&nfs_reqcache_pool, sizeof(struct nfsrvcache), 0, 0, 0, 171 "nfsreqcachepl", &pool_allocator_nointr, IPL_NONE); 172 MOWNER_ATTACH(&nfsd_cache_mowner); 173 } 174 175 /* 176 * Lookup a cache and lock it 177 */ 178 static struct nfsrvcache * 179 nfsrv_lookupcache(nd) 180 struct nfsrv_descript *nd; 181 { 182 struct nfsrvcache *rp; 183 184 KASSERT(mutex_owned(&nfsrv_reqcache_lock)); 185 186 loop: 187 LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) { 188 if (nd->nd_retxid == rp->rc_xid && 189 nd->nd_procnum == rp->rc_proc && 190 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 191 if ((rp->rc_gflags & RC_G_LOCKED) != 0) { 192 cv_wait(&rp->rc_cv, &nfsrv_reqcache_lock); 193 goto loop; 194 } 195 rp->rc_gflags |= RC_G_LOCKED; 196 break; 197 } 198 } 199 200 return rp; 201 } 202 203 /* 204 * Unlock a cache 205 */ 206 static void 207 nfsrv_unlockcache(rp) 208 struct nfsrvcache *rp; 209 { 210 211 KASSERT(mutex_owned(&nfsrv_reqcache_lock)); 212 213 KASSERT((rp->rc_gflags & RC_G_LOCKED) != 0); 214 rp->rc_gflags &= ~RC_G_LOCKED; 215 cv_broadcast(&rp->rc_cv); 216 } 217 218 /* 219 * Look for the request in the cache 220 * If found then 221 * return action and optionally reply 222 * else 223 * insert it in the cache 224 * 225 * The rules are as follows: 226 * - if in progress, return DROP request 227 * - if completed within DELAY of the current time, return DROP it 228 * - if completed a longer time ago return REPLY if the reply was cached or 229 * return DOIT 230 * Update/add new request at end of lru list 231 */ 232 int 233 nfsrv_getcache(nd, slp, repp) 234 struct nfsrv_descript *nd; 235 struct nfssvc_sock *slp; 236 struct mbuf **repp; 237 { 238 struct nfsrvcache *rp, *rpdup; 239 struct mbuf *mb; 240 struct sockaddr_in *saddr; 241 char *bpos; 242 int ret; 243 244 mutex_enter(&nfsrv_reqcache_lock); 245 rp = nfsrv_lookupcache(nd); 246 if (rp) { 247 mutex_exit(&nfsrv_reqcache_lock); 248 found: 249 /* If not at end of LRU chain, move it there */ 250 if (TAILQ_NEXT(rp, rc_lru)) { /* racy but ok */ 251 mutex_enter(&nfsrv_reqcache_lock); 252 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 253 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 254 mutex_exit(&nfsrv_reqcache_lock); 255 } 256 if (rp->rc_state == RC_UNUSED) 257 panic("nfsrv cache"); 258 if (rp->rc_state == RC_INPROG) { 259 nfsstats.srvcache_inproghits++; 260 ret = RC_DROPIT; 261 } else if (rp->rc_flags & RC_REPSTATUS) { 262 nfsstats.srvcache_nonidemdonehits++; 263 nfs_rephead(0, nd, slp, rp->rc_status, 264 0, (u_quad_t *)0, repp, &mb, &bpos); 265 ret = RC_REPLY; 266 } else if (rp->rc_flags & RC_REPMBUF) { 267 nfsstats.srvcache_nonidemdonehits++; 268 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, 269 M_WAIT); 270 ret = RC_REPLY; 271 } else { 272 nfsstats.srvcache_idemdonehits++; 273 rp->rc_state = RC_INPROG; 274 ret = RC_DOIT; 275 } 276 mutex_enter(&nfsrv_reqcache_lock); 277 nfsrv_unlockcache(rp); 278 mutex_exit(&nfsrv_reqcache_lock); 279 return ret; 280 } 281 nfsstats.srvcache_misses++; 282 if (numnfsrvcache < desirednfsrvcache) { 283 numnfsrvcache++; 284 mutex_exit(&nfsrv_reqcache_lock); 285 rp = pool_get(&nfs_reqcache_pool, PR_WAITOK); 286 memset(rp, 0, sizeof *rp); 287 cv_init(&rp->rc_cv, "nfsdrc"); 288 rp->rc_gflags = RC_G_LOCKED; 289 } else { 290 rp = TAILQ_FIRST(&nfsrvlruhead); 291 while ((rp->rc_gflags & RC_G_LOCKED) != 0) { 292 cv_wait(&rp->rc_cv, &nfsrv_reqcache_lock); 293 rp = TAILQ_FIRST(&nfsrvlruhead); 294 } 295 rp->rc_gflags |= RC_G_LOCKED; 296 LIST_REMOVE(rp, rc_hash); 297 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 298 mutex_exit(&nfsrv_reqcache_lock); 299 cleanentry(rp); 300 rp->rc_flags = 0; 301 } 302 rp->rc_state = RC_INPROG; 303 rp->rc_xid = nd->nd_retxid; 304 saddr = mtod(nd->nd_nam, struct sockaddr_in *); 305 switch (saddr->sin_family) { 306 case AF_INET: 307 rp->rc_flags |= RC_INETADDR; 308 rp->rc_inetaddr = saddr->sin_addr.s_addr; 309 break; 310 case AF_ISO: 311 default: 312 rp->rc_flags |= RC_NAM; 313 rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT); 314 m_claimm(rp->rc_nam, &nfsd_cache_mowner); 315 break; 316 }; 317 rp->rc_proc = nd->nd_procnum; 318 mutex_enter(&nfsrv_reqcache_lock); 319 rpdup = nfsrv_lookupcache(nd); 320 if (rpdup != NULL) { 321 /* 322 * other thread made duplicate cache entry. 323 */ 324 KASSERT(numnfsrvcache > 0); 325 numnfsrvcache--; 326 mutex_exit(&nfsrv_reqcache_lock); 327 cleanentry(rp); 328 cv_destroy(&rp->rc_cv); 329 pool_put(&nfs_reqcache_pool, rp); 330 rp = rpdup; 331 goto found; 332 } 333 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 334 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash); 335 nfsrv_unlockcache(rp); 336 mutex_exit(&nfsrv_reqcache_lock); 337 return RC_DOIT; 338 } 339 340 /* 341 * Update a request cache entry after the rpc has been done 342 */ 343 void 344 nfsrv_updatecache(nd, repvalid, repmbuf) 345 struct nfsrv_descript *nd; 346 int repvalid; 347 struct mbuf *repmbuf; 348 { 349 struct nfsrvcache *rp; 350 351 mutex_enter(&nfsrv_reqcache_lock); 352 rp = nfsrv_lookupcache(nd); 353 mutex_exit(&nfsrv_reqcache_lock); 354 if (rp) { 355 cleanentry(rp); 356 rp->rc_state = RC_DONE; 357 /* 358 * If we have a valid reply update status and save 359 * the reply for non-idempotent rpc's. 360 */ 361 if (repvalid && nonidempotent[nd->nd_procnum]) { 362 if ((nd->nd_flag & ND_NFSV3) == 0 && 363 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) { 364 rp->rc_status = nd->nd_repstat; 365 rp->rc_flags |= RC_REPSTATUS; 366 } else { 367 rp->rc_reply = m_copym(repmbuf, 368 0, M_COPYALL, M_WAIT); 369 m_claimm(rp->rc_reply, &nfsd_cache_mowner); 370 rp->rc_flags |= RC_REPMBUF; 371 } 372 } 373 mutex_enter(&nfsrv_reqcache_lock); 374 nfsrv_unlockcache(rp); 375 mutex_exit(&nfsrv_reqcache_lock); 376 } 377 } 378 379 /* 380 * Clean out the cache. Called when the last nfsd terminates. 381 */ 382 void 383 nfsrv_cleancache() 384 { 385 struct nfsrvcache *rp; 386 387 mutex_enter(&nfsrv_reqcache_lock); 388 while ((rp = TAILQ_FIRST(&nfsrvlruhead)) != NULL) { 389 KASSERT((rp->rc_gflags & RC_G_LOCKED) == 0); 390 LIST_REMOVE(rp, rc_hash); 391 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 392 KASSERT(numnfsrvcache > 0); 393 numnfsrvcache--; 394 mutex_exit(&nfsrv_reqcache_lock); 395 cleanentry(rp); 396 cv_destroy(&rp->rc_cv); 397 pool_put(&nfs_reqcache_pool, rp); 398 mutex_enter(&nfsrv_reqcache_lock); 399 } 400 KASSERT(numnfsrvcache == 0); 401 mutex_exit(&nfsrv_reqcache_lock); 402 } 403
Indexes created Tue Sep 23 23:09:58 GMT 2025