1 /* $NetBSD: nfs_srvcache.c,v 1.45 2009/03/15 17:20:10 cegger 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 1.45 2009/03/15 17:20:10 cegger Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/vnode.h> 48 #include <sys/condvar.h> 49 #include <sys/mount.h> 50 #include <sys/kernel.h> 51 #include <sys/systm.h> 52 #include <sys/lock.h> 53 #include <sys/proc.h> 54 #include <sys/pool.h> 55 #include <sys/mbuf.h> 56 #include <sys/mutex.h> 57 #include <sys/socket.h> 58 #include <sys/socketvar.h> 59 60 #include <netinet/in.h> 61 #include <nfs/nfsm_subs.h> 62 #include <nfs/rpcv2.h> 63 #include <nfs/nfsproto.h> 64 #include <nfs/nfs.h> 65 #include <nfs/nfsrvcache.h> 66 #include <nfs/nfs_var.h> 67 68 extern struct nfsstats nfsstats; 69 extern const int nfsv2_procid[NFS_NPROCS]; 70 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ; 71 struct pool nfs_reqcache_pool; 72 73 #define NFSRCHASH(xid) \ 74 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 75 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 76 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 77 kmutex_t nfsrv_reqcache_lock; 78 u_long nfsrvhash; 79 80 #if defined(MBUFTRACE) 81 static struct mowner nfsd_cache_mowner = MOWNER_INIT("nfsd", "cache"); 82 #endif /* defined(MBUFTRACE) */ 83 84 #define NETFAMILY(rp) \ 85 (((rp)->rc_flags & RC_INETADDR) ? AF_INET : -1) 86 87 static struct nfsrvcache *nfsrv_lookupcache(struct nfsrv_descript *nd); 88 static void nfsrv_unlockcache(struct nfsrvcache *rp); 89 90 /* 91 * Static array that defines which nfs rpc's are nonidempotent 92 */ 93 const int nonidempotent[NFS_NPROCS] = { 94 false, /* NULL */ 95 false, /* GETATTR */ 96 true, /* SETATTR */ 97 false, /* LOOKUP */ 98 false, /* ACCESS */ 99 false, /* READLINK */ 100 false, /* READ */ 101 true, /* WRITE */ 102 true, /* CREATE */ 103 true, /* MKDIR */ 104 true, /* SYMLINK */ 105 true, /* MKNOD */ 106 true, /* REMOVE */ 107 true, /* RMDIR */ 108 true, /* RENAME */ 109 true, /* LINK */ 110 false, /* READDIR */ 111 false, /* READDIRPLUS */ 112 false, /* FSSTAT */ 113 false, /* FSINFO */ 114 false, /* PATHCONF */ 115 false, /* COMMIT */ 116 false, /* NOOP */ 117 }; 118 119 /* True iff the rpc reply is an nfs status ONLY! */ 120 static const int nfsv2_repstat[NFS_NPROCS] = { 121 false, /* NULL */ 122 false, /* GETATTR */ 123 false, /* SETATTR */ 124 false, /* NOOP */ 125 false, /* LOOKUP */ 126 false, /* READLINK */ 127 false, /* READ */ 128 false, /* Obsolete WRITECACHE */ 129 false, /* WRITE */ 130 false, /* CREATE */ 131 true, /* REMOVE */ 132 true, /* RENAME */ 133 true, /* LINK */ 134 true, /* SYMLINK */ 135 false, /* MKDIR */ 136 true, /* RMDIR */ 137 false, /* READDIR */ 138 false, /* STATFS */ 139 }; 140 141 static void 142 cleanentry(struct nfsrvcache *rp) 143 { 144 145 if ((rp->rc_flags & RC_REPMBUF) != 0) { 146 m_freem(rp->rc_reply); 147 } 148 if ((rp->rc_flags & RC_NAM) != 0) { 149 m_free(rp->rc_nam); 150 } 151 rp->rc_flags &= ~(RC_REPSTATUS|RC_REPMBUF); 152 } 153 154 /* 155 * Initialize the server request cache list 156 */ 157 void 158 nfsrv_initcache(void) 159 { 160 161 mutex_init(&nfsrv_reqcache_lock, MUTEX_DEFAULT, IPL_NONE); 162 nfsrvhashtbl = hashinit(desirednfsrvcache, HASH_LIST, true, 163 &nfsrvhash); 164 TAILQ_INIT(&nfsrvlruhead); 165 pool_init(&nfs_reqcache_pool, sizeof(struct nfsrvcache), 0, 0, 0, 166 "nfsreqcachepl", &pool_allocator_nointr, IPL_NONE); 167 MOWNER_ATTACH(&nfsd_cache_mowner); 168 } 169 170 void 171 nfsrv_finicache(void) 172 { 173 174 nfsrv_cleancache(); 175 KASSERT(TAILQ_EMPTY(&nfsrvlruhead)); 176 pool_destroy(&nfs_reqcache_pool); 177 hashdone(nfsrvhashtbl, HASH_LIST, nfsrvhash); 178 MOWNER_DETACH(&nfsd_cache_mowner); 179 mutex_destroy(&nfsrv_reqcache_lock); 180 } 181 182 /* 183 * Lookup a cache and lock it 184 */ 185 static struct nfsrvcache * 186 nfsrv_lookupcache(struct nfsrv_descript *nd) 187 { 188 struct nfsrvcache *rp; 189 190 KASSERT(mutex_owned(&nfsrv_reqcache_lock)); 191 192 loop: 193 LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) { 194 if (nd->nd_retxid == rp->rc_xid && 195 nd->nd_procnum == rp->rc_proc && 196 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 197 if ((rp->rc_gflags & RC_G_LOCKED) != 0) { 198 cv_wait(&rp->rc_cv, &nfsrv_reqcache_lock); 199 goto loop; 200 } 201 rp->rc_gflags |= RC_G_LOCKED; 202 break; 203 } 204 } 205 206 return rp; 207 } 208 209 /* 210 * Unlock a cache 211 */ 212 static void 213 nfsrv_unlockcache(struct nfsrvcache *rp) 214 { 215 216 KASSERT(mutex_owned(&nfsrv_reqcache_lock)); 217 218 KASSERT((rp->rc_gflags & RC_G_LOCKED) != 0); 219 rp->rc_gflags &= ~RC_G_LOCKED; 220 cv_broadcast(&rp->rc_cv); 221 } 222 223 /* 224 * Look for the request in the cache 225 * If found then 226 * return action and optionally reply 227 * else 228 * insert it in the cache 229 * 230 * The rules are as follows: 231 * - if in progress, return DROP request 232 * - if completed within DELAY of the current time, return DROP it 233 * - if completed a longer time ago return REPLY if the reply was cached or 234 * return DOIT 235 * Update/add new request at end of lru list 236 */ 237 int 238 nfsrv_getcache(struct nfsrv_descript *nd, struct nfssvc_sock *slp, struct mbuf **repp) 239 { 240 struct nfsrvcache *rp, *rpdup; 241 struct mbuf *mb; 242 struct sockaddr_in *saddr; 243 char *bpos; 244 int ret; 245 246 mutex_enter(&nfsrv_reqcache_lock); 247 rp = nfsrv_lookupcache(nd); 248 if (rp) { 249 mutex_exit(&nfsrv_reqcache_lock); 250 found: 251 /* If not at end of LRU chain, move it there */ 252 if (TAILQ_NEXT(rp, rc_lru)) { /* racy but ok */ 253 mutex_enter(&nfsrv_reqcache_lock); 254 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 255 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 256 mutex_exit(&nfsrv_reqcache_lock); 257 } 258 if (rp->rc_state == RC_UNUSED) 259 panic("nfsrv cache"); 260 if (rp->rc_state == RC_INPROG) { 261 nfsstats.srvcache_inproghits++; 262 ret = RC_DROPIT; 263 } else if (rp->rc_flags & RC_REPSTATUS) { 264 nfsstats.srvcache_nonidemdonehits++; 265 nfs_rephead(0, nd, slp, rp->rc_status, 266 0, (u_quad_t *)0, repp, &mb, &bpos); 267 ret = RC_REPLY; 268 } else if (rp->rc_flags & RC_REPMBUF) { 269 nfsstats.srvcache_nonidemdonehits++; 270 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, 271 M_WAIT); 272 ret = RC_REPLY; 273 } else { 274 nfsstats.srvcache_idemdonehits++; 275 rp->rc_state = RC_INPROG; 276 ret = RC_DOIT; 277 } 278 mutex_enter(&nfsrv_reqcache_lock); 279 nfsrv_unlockcache(rp); 280 mutex_exit(&nfsrv_reqcache_lock); 281 return ret; 282 } 283 nfsstats.srvcache_misses++; 284 if (numnfsrvcache < desirednfsrvcache) { 285 numnfsrvcache++; 286 mutex_exit(&nfsrv_reqcache_lock); 287 rp = pool_get(&nfs_reqcache_pool, PR_WAITOK); 288 memset(rp, 0, sizeof *rp); 289 cv_init(&rp->rc_cv, "nfsdrc"); 290 rp->rc_gflags = RC_G_LOCKED; 291 } else { 292 rp = TAILQ_FIRST(&nfsrvlruhead); 293 while ((rp->rc_gflags & RC_G_LOCKED) != 0) { 294 cv_wait(&rp->rc_cv, &nfsrv_reqcache_lock); 295 rp = TAILQ_FIRST(&nfsrvlruhead); 296 } 297 rp->rc_gflags |= RC_G_LOCKED; 298 LIST_REMOVE(rp, rc_hash); 299 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 300 mutex_exit(&nfsrv_reqcache_lock); 301 cleanentry(rp); 302 rp->rc_flags = 0; 303 } 304 rp->rc_state = RC_INPROG; 305 rp->rc_xid = nd->nd_retxid; 306 saddr = mtod(nd->nd_nam, struct sockaddr_in *); 307 switch (saddr->sin_family) { 308 case AF_INET: 309 rp->rc_flags |= RC_INETADDR; 310 rp->rc_inetaddr = saddr->sin_addr.s_addr; 311 break; 312 default: 313 rp->rc_flags |= RC_NAM; 314 rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT); 315 m_claimm(rp->rc_nam, &nfsd_cache_mowner); 316 break; 317 }; 318 rp->rc_proc = nd->nd_procnum; 319 mutex_enter(&nfsrv_reqcache_lock); 320 rpdup = nfsrv_lookupcache(nd); 321 if (rpdup != NULL) { 322 /* 323 * other thread made duplicate cache entry. 324 */ 325 KASSERT(numnfsrvcache > 0); 326 numnfsrvcache--; 327 mutex_exit(&nfsrv_reqcache_lock); 328 cleanentry(rp); 329 cv_destroy(&rp->rc_cv); 330 pool_put(&nfs_reqcache_pool, rp); 331 rp = rpdup; 332 goto found; 333 } 334 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 335 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash); 336 nfsrv_unlockcache(rp); 337 mutex_exit(&nfsrv_reqcache_lock); 338 return RC_DOIT; 339 } 340 341 /* 342 * Update a request cache entry after the rpc has been done 343 */ 344 void 345 nfsrv_updatecache(struct nfsrv_descript *nd, int repvalid, struct mbuf *repmbuf) 346 { 347 struct nfsrvcache *rp; 348 349 mutex_enter(&nfsrv_reqcache_lock); 350 rp = nfsrv_lookupcache(nd); 351 mutex_exit(&nfsrv_reqcache_lock); 352 if (rp) { 353 cleanentry(rp); 354 rp->rc_state = RC_DONE; 355 /* 356 * If we have a valid reply update status and save 357 * the reply for non-idempotent rpc's. 358 */ 359 if (repvalid && nonidempotent[nd->nd_procnum]) { 360 if ((nd->nd_flag & ND_NFSV3) == 0 && 361 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) { 362 rp->rc_status = nd->nd_repstat; 363 rp->rc_flags |= RC_REPSTATUS; 364 } else { 365 rp->rc_reply = m_copym(repmbuf, 366 0, M_COPYALL, M_WAIT); 367 m_claimm(rp->rc_reply, &nfsd_cache_mowner); 368 rp->rc_flags |= RC_REPMBUF; 369 } 370 } 371 mutex_enter(&nfsrv_reqcache_lock); 372 nfsrv_unlockcache(rp); 373 mutex_exit(&nfsrv_reqcache_lock); 374 } 375 } 376 377 /* 378 * Clean out the cache. Called when the last nfsd terminates. 379 */ 380 void 381 nfsrv_cleancache(void) 382 { 383 struct nfsrvcache *rp; 384 385 mutex_enter(&nfsrv_reqcache_lock); 386 while ((rp = TAILQ_FIRST(&nfsrvlruhead)) != NULL) { 387 KASSERT((rp->rc_gflags & RC_G_LOCKED) == 0); 388 LIST_REMOVE(rp, rc_hash); 389 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 390 KASSERT(numnfsrvcache > 0); 391 numnfsrvcache--; 392 mutex_exit(&nfsrv_reqcache_lock); 393 cleanentry(rp); 394 cv_destroy(&rp->rc_cv); 395 pool_put(&nfs_reqcache_pool, rp); 396 mutex_enter(&nfsrv_reqcache_lock); 397 } 398 KASSERT(numnfsrvcache == 0); 399 mutex_exit(&nfsrv_reqcache_lock); 400 } 401
Indexes created Sun Sep 21 20:09:37 GMT 2025