nfs_srvcache.c revision 1.41
1 /* $NetBSD: nfs_srvcache.c,v 1.41 2007/12/04 17:42:31 yamt 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 1.41 2007/12/04 17:42:31 yamt 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/malloc.h> 59 #include <sys/mutex.h> 60 #include <sys/socket.h> 61 #include <sys/socketvar.h> 62 63 #include <netinet/in.h> 64 #ifdef ISO 65 #include <netiso/iso.h> 66 #endif 67 #include <nfs/nfsm_subs.h> 68 #include <nfs/rpcv2.h> 69 #include <nfs/nfsproto.h> 70 #include <nfs/nfs.h> 71 #include <nfs/nfsrvcache.h> 72 #include <nfs/nfs_var.h> 73 74 extern struct nfsstats nfsstats; 75 extern const int nfsv2_procid[NFS_NPROCS]; 76 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ; 77 struct pool nfs_reqcache_pool; 78 79 #define NFSRCHASH(xid) \ 80 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 81 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 82 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 83 kmutex_t nfsrv_reqcache_lock; 84 u_long nfsrvhash; 85 86 #if defined(MBUFTRACE) 87 static struct mowner nfsd_cache_mowner = MOWNER_INIT("nfsd", "cache"); 88 #endif /* defined(MBUFTRACE) */ 89 90 #define NETFAMILY(rp) \ 91 (((rp)->rc_flags & RC_INETADDR) ? AF_INET : AF_ISO) 92 93 static struct nfsrvcache *nfsrv_lookupcache(struct nfsrv_descript *nd); 94 static void nfsrv_unlockcache(struct nfsrvcache *rp); 95 96 /* 97 * Static array that defines which nfs rpc's are nonidempotent 98 */ 99 const int nonidempotent[NFS_NPROCS] = { 100 false, /* NULL */ 101 false, /* GETATTR */ 102 true, /* SETATTR */ 103 false, /* LOOKUP */ 104 false, /* ACCESS */ 105 false, /* READLINK */ 106 false, /* READ */ 107 true, /* WRITE */ 108 true, /* CREATE */ 109 true, /* MKDIR */ 110 true, /* SYMLINK */ 111 true, /* MKNOD */ 112 true, /* REMOVE */ 113 true, /* RMDIR */ 114 true, /* RENAME */ 115 true, /* LINK */ 116 false, /* READDIR */ 117 false, /* READDIRPLUS */ 118 false, /* FSSTAT */ 119 false, /* FSINFO */ 120 false, /* PATHCONF */ 121 false, /* COMMIT */ 122 false, /* NOOP */ 123 }; 124 125 /* True iff the rpc reply is an nfs status ONLY! */ 126 static const int nfsv2_repstat[NFS_NPROCS] = { 127 false, /* NULL */ 128 false, /* GETATTR */ 129 false, /* SETATTR */ 130 false, /* NOOP */ 131 false, /* LOOKUP */ 132 false, /* READLINK */ 133 false, /* READ */ 134 false, /* Obsolete WRITECACHE */ 135 false, /* WRITE */ 136 false, /* CREATE */ 137 true, /* REMOVE */ 138 true, /* RENAME */ 139 true, /* LINK */ 140 true, /* SYMLINK */ 141 false, /* MKDIR */ 142 true, /* RMDIR */ 143 false, /* READDIR */ 144 false, /* STATFS */ 145 }; 146 147 static void 148 cleanentry(struct nfsrvcache *rp) 149 { 150 151 if ((rp->rc_flags & RC_REPMBUF) != 0) { 152 m_freem(rp->rc_reply); 153 } 154 if ((rp->rc_flags & RC_NAM) != 0) { 155 m_free(rp->rc_nam); 156 } 157 rp->rc_flags &= ~(RC_REPSTATUS|RC_REPMBUF); 158 } 159 160 /* 161 * Initialize the server request cache list 162 */ 163 void 164 nfsrv_initcache() 165 { 166 167 mutex_init(&nfsrv_reqcache_lock, MUTEX_DEFAULT, IPL_NONE); 168 nfsrvhashtbl = hashinit(desirednfsrvcache, HASH_LIST, M_NFSD, 169 M_WAITOK, &nfsrvhash); 170 TAILQ_INIT(&nfsrvlruhead); 171 pool_init(&nfs_reqcache_pool, sizeof(struct nfsrvcache), 0, 0, 0, 172 "nfsreqcachepl", &pool_allocator_nointr, IPL_NONE); 173 MOWNER_ATTACH(&nfsd_cache_mowner); 174 } 175 176 /* 177 * Lookup a cache and lock it 178 */ 179 static struct nfsrvcache * 180 nfsrv_lookupcache(nd) 181 struct nfsrv_descript *nd; 182 { 183 struct nfsrvcache *rp; 184 185 KASSERT(mutex_owned(&nfsrv_reqcache_lock)); 186 187 loop: 188 LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) { 189 if (nd->nd_retxid == rp->rc_xid && 190 nd->nd_procnum == rp->rc_proc && 191 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 192 if ((rp->rc_gflags & RC_G_LOCKED) != 0) { 193 cv_wait(&rp->rc_cv, &nfsrv_reqcache_lock); 194 goto loop; 195 } 196 rp->rc_gflags |= RC_G_LOCKED; 197 break; 198 } 199 } 200 201 return rp; 202 } 203 204 /* 205 * Unlock a cache 206 */ 207 static void 208 nfsrv_unlockcache(rp) 209 struct nfsrvcache *rp; 210 { 211 212 KASSERT(mutex_owned(&nfsrv_reqcache_lock)); 213 214 KASSERT((rp->rc_gflags & RC_G_LOCKED) != 0); 215 rp->rc_gflags &= ~RC_G_LOCKED; 216 cv_broadcast(&rp->rc_cv); 217 } 218 219 /* 220 * Look for the request in the cache 221 * If found then 222 * return action and optionally reply 223 * else 224 * insert it in the cache 225 * 226 * The rules are as follows: 227 * - if in progress, return DROP request 228 * - if completed within DELAY of the current time, return DROP it 229 * - if completed a longer time ago return REPLY if the reply was cached or 230 * return DOIT 231 * Update/add new request at end of lru list 232 */ 233 int 234 nfsrv_getcache(nd, slp, repp) 235 struct nfsrv_descript *nd; 236 struct nfssvc_sock *slp; 237 struct mbuf **repp; 238 { 239 struct nfsrvcache *rp, *rpdup; 240 struct mbuf *mb; 241 struct sockaddr_in *saddr; 242 char *bpos; 243 int ret; 244 245 mutex_enter(&nfsrv_reqcache_lock); 246 rp = nfsrv_lookupcache(nd); 247 if (rp) { 248 mutex_exit(&nfsrv_reqcache_lock); 249 found: 250 /* If not at end of LRU chain, move it there */ 251 if (TAILQ_NEXT(rp, rc_lru)) { /* racy but ok */ 252 mutex_enter(&nfsrv_reqcache_lock); 253 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 254 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 255 mutex_exit(&nfsrv_reqcache_lock); 256 } 257 if (rp->rc_state == RC_UNUSED) 258 panic("nfsrv cache"); 259 if (rp->rc_state == RC_INPROG) { 260 nfsstats.srvcache_inproghits++; 261 ret = RC_DROPIT; 262 } else if (rp->rc_flags & RC_REPSTATUS) { 263 nfsstats.srvcache_nonidemdonehits++; 264 nfs_rephead(0, nd, slp, rp->rc_status, 265 0, (u_quad_t *)0, repp, &mb, &bpos); 266 ret = RC_REPLY; 267 } else if (rp->rc_flags & RC_REPMBUF) { 268 nfsstats.srvcache_nonidemdonehits++; 269 *repp = m_copym(rp->rc_reply, 0, M_COPYALL, 270 M_WAIT); 271 ret = RC_REPLY; 272 } else { 273 nfsstats.srvcache_idemdonehits++; 274 rp->rc_state = RC_INPROG; 275 ret = RC_DOIT; 276 } 277 mutex_enter(&nfsrv_reqcache_lock); 278 nfsrv_unlockcache(rp); 279 mutex_exit(&nfsrv_reqcache_lock); 280 return ret; 281 } 282 nfsstats.srvcache_misses++; 283 if (numnfsrvcache < desirednfsrvcache) { 284 numnfsrvcache++; 285 mutex_exit(&nfsrv_reqcache_lock); 286 rp = pool_get(&nfs_reqcache_pool, PR_WAITOK); 287 memset(rp, 0, sizeof *rp); 288 cv_init(&rp->rc_cv, "nfsdrc"); 289 rp->rc_gflags = RC_G_LOCKED; 290 } else { 291 rp = TAILQ_FIRST(&nfsrvlruhead); 292 while ((rp->rc_gflags & RC_G_LOCKED) != 0) { 293 cv_wait(&rp->rc_cv, &nfsrv_reqcache_lock); 294 rp = TAILQ_FIRST(&nfsrvlruhead); 295 } 296 rp->rc_gflags |= RC_G_LOCKED; 297 LIST_REMOVE(rp, rc_hash); 298 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 299 mutex_exit(&nfsrv_reqcache_lock); 300 cleanentry(rp); 301 rp->rc_flags = 0; 302 } 303 rp->rc_state = RC_INPROG; 304 rp->rc_xid = nd->nd_retxid; 305 saddr = mtod(nd->nd_nam, struct sockaddr_in *); 306 switch (saddr->sin_family) { 307 case AF_INET: 308 rp->rc_flags |= RC_INETADDR; 309 rp->rc_inetaddr = saddr->sin_addr.s_addr; 310 break; 311 case AF_ISO: 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(nd, repvalid, repmbuf) 346 struct nfsrv_descript *nd; 347 int repvalid; 348 struct mbuf *repmbuf; 349 { 350 struct nfsrvcache *rp; 351 352 mutex_enter(&nfsrv_reqcache_lock); 353 rp = nfsrv_lookupcache(nd); 354 mutex_exit(&nfsrv_reqcache_lock); 355 if (rp) { 356 cleanentry(rp); 357 rp->rc_state = RC_DONE; 358 /* 359 * If we have a valid reply update status and save 360 * the reply for non-idempotent rpc's. 361 */ 362 if (repvalid && nonidempotent[nd->nd_procnum]) { 363 if ((nd->nd_flag & ND_NFSV3) == 0 && 364 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) { 365 rp->rc_status = nd->nd_repstat; 366 rp->rc_flags |= RC_REPSTATUS; 367 } else { 368 rp->rc_reply = m_copym(repmbuf, 369 0, M_COPYALL, M_WAIT); 370 m_claimm(rp->rc_reply, &nfsd_cache_mowner); 371 rp->rc_flags |= RC_REPMBUF; 372 } 373 } 374 mutex_enter(&nfsrv_reqcache_lock); 375 nfsrv_unlockcache(rp); 376 mutex_exit(&nfsrv_reqcache_lock); 377 } 378 } 379 380 /* 381 * Clean out the cache. Called when the last nfsd terminates. 382 */ 383 void 384 nfsrv_cleancache() 385 { 386 struct nfsrvcache *rp; 387 388 mutex_enter(&nfsrv_reqcache_lock); 389 while ((rp = TAILQ_FIRST(&nfsrvlruhead)) != NULL) { 390 KASSERT((rp->rc_gflags & RC_G_LOCKED) == 0); 391 LIST_REMOVE(rp, rc_hash); 392 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 393 KASSERT(numnfsrvcache > 0); 394 numnfsrvcache--; 395 mutex_exit(&nfsrv_reqcache_lock); 396 cleanentry(rp); 397 cv_destroy(&rp->rc_cv); 398 pool_put(&nfs_reqcache_pool, rp); 399 mutex_enter(&nfsrv_reqcache_lock); 400 } 401 KASSERT(numnfsrvcache == 0); 402 mutex_exit(&nfsrv_reqcache_lock); 403 } 404
Indexes created Tue Sep 23 22:09:46 GMT 2025