nfs_srvcache.c revision 1.39
1 /* $NetBSD: nfs_srvcache.c,v 1.39 2007/03/12 18:18:36 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 1.39 2007/03/12 18:18:36 ad Exp $"); 45 46 #include "opt_iso.h" 47 48 #include <sys/param.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/kernel.h> 52 #include <sys/systm.h> 53 #include <sys/lock.h> 54 #include <sys/proc.h> 55 #include <sys/pool.h> 56 #include <sys/mbuf.h> 57 #include <sys/malloc.h> 58 #include <sys/socket.h> 59 #include <sys/socketvar.h> 60 61 #include <netinet/in.h> 62 #ifdef ISO 63 #include <netiso/iso.h> 64 #endif 65 #include <nfs/nfsm_subs.h> 66 #include <nfs/rpcv2.h> 67 #include <nfs/nfsproto.h> 68 #include <nfs/nfs.h> 69 #include <nfs/nfsrvcache.h> 70 #include <nfs/nfs_var.h> 71 72 extern struct nfsstats nfsstats; 73 extern const int nfsv2_procid[NFS_NPROCS]; 74 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ; 75 struct pool nfs_reqcache_pool; 76 77 #define NFSRCHASH(xid) \ 78 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash]) 79 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl; 80 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead; 81 struct simplelock nfsrv_reqcache_lock = SIMPLELOCK_INITIALIZER; 82 u_long nfsrvhash; 83 84 #if defined(MBUFTRACE) 85 static struct mowner nfsd_cache_mowner = MOWNER_INIT("nfsd", "cache"); 86 #endif /* defined(MBUFTRACE) */ 87 88 #define NETFAMILY(rp) \ 89 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO) 90 91 static struct nfsrvcache *nfsrv_lookupcache(struct nfsrv_descript *nd); 92 static void nfsrv_unlockcache(struct nfsrvcache *rp); 93 94 /* 95 * Static array that defines which nfs rpc's are nonidempotent 96 */ 97 const int nonidempotent[NFS_NPROCS] = { 98 false, /* NULL */ 99 false, /* GETATTR */ 100 true, /* SETATTR */ 101 false, /* LOOKUP */ 102 false, /* ACCESS */ 103 false, /* READLINK */ 104 false, /* READ */ 105 true, /* WRITE */ 106 true, /* CREATE */ 107 true, /* MKDIR */ 108 true, /* SYMLINK */ 109 true, /* MKNOD */ 110 true, /* REMOVE */ 111 true, /* RMDIR */ 112 true, /* RENAME */ 113 true, /* LINK */ 114 false, /* READDIR */ 115 false, /* READDIRPLUS */ 116 false, /* FSSTAT */ 117 false, /* FSINFO */ 118 false, /* PATHCONF */ 119 false, /* COMMIT */ 120 false, /* NOOP */ 121 }; 122 123 /* True iff the rpc reply is an nfs status ONLY! */ 124 static const int nfsv2_repstat[NFS_NPROCS] = { 125 false, /* NULL */ 126 false, /* GETATTR */ 127 false, /* SETATTR */ 128 false, /* NOOP */ 129 false, /* LOOKUP */ 130 false, /* READLINK */ 131 false, /* READ */ 132 false, /* Obsolete WRITECACHE */ 133 false, /* WRITE */ 134 false, /* CREATE */ 135 true, /* REMOVE */ 136 true, /* RENAME */ 137 true, /* LINK */ 138 true, /* SYMLINK */ 139 false, /* MKDIR */ 140 true, /* RMDIR */ 141 false, /* READDIR */ 142 false, /* STATFS */ 143 }; 144 145 static void 146 cleanentry(struct nfsrvcache *rp) 147 { 148 149 if ((rp->rc_flag & RC_REPMBUF) != 0) { 150 m_freem(rp->rc_reply); 151 } 152 if ((rp->rc_flag & RC_NAM) != 0) { 153 m_free(rp->rc_nam); 154 } 155 rp->rc_flag &= ~(RC_REPSTATUS|RC_REPMBUF); 156 } 157 158 /* 159 * Initialize the server request cache list 160 */ 161 void 162 nfsrv_initcache() 163 { 164 165 nfsrvhashtbl = hashinit(desirednfsrvcache, HASH_LIST, M_NFSD, 166 M_WAITOK, &nfsrvhash); 167 TAILQ_INIT(&nfsrvlruhead); 168 pool_init(&nfs_reqcache_pool, sizeof(struct nfsrvcache), 0, 0, 0, 169 "nfsreqcachepl", &pool_allocator_nointr, IPL_NONE); 170 MOWNER_ATTACH(&nfsd_cache_mowner); 171 } 172 173 /* 174 * Lookup a cache and lock it 175 */ 176 static struct nfsrvcache * 177 nfsrv_lookupcache(nd) 178 struct nfsrv_descript *nd; 179 { 180 struct nfsrvcache *rp; 181 182 LOCK_ASSERT(simple_lock_held(&nfsrv_reqcache_lock)); 183 184 loop: 185 LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) { 186 if (nd->nd_retxid == rp->rc_xid && 187 nd->nd_procnum == rp->rc_proc && 188 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) { 189 if ((rp->rc_flag & RC_LOCKED) != 0) { 190 rp->rc_flag |= RC_WANTED; 191 (void) ltsleep(rp, PZERO - 1, "nfsrc", 0, 192 &nfsrv_reqcache_lock); 193 goto loop; 194 } 195 rp->rc_flag |= RC_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 LOCK_ASSERT(simple_lock_held(&nfsrv_reqcache_lock)); 212 213 rp->rc_flag &= ~RC_LOCKED; 214 if (rp->rc_flag & RC_WANTED) { 215 rp->rc_flag &= ~RC_WANTED; 216 wakeup(rp); 217 } 218 } 219 220 /* 221 * Look for the request in the cache 222 * If found then 223 * return action and optionally reply 224 * else 225 * insert it in the cache 226 * 227 * The rules are as follows: 228 * - if in progress, return DROP request 229 * - if completed within DELAY of the current time, return DROP it 230 * - if completed a longer time ago return REPLY if the reply was cached or 231 * return DOIT 232 * Update/add new request at end of lru list 233 */ 234 int 235 nfsrv_getcache(nd, slp, repp) 236 struct nfsrv_descript *nd; 237 struct nfssvc_sock *slp; 238 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 simple_lock(&nfsrv_reqcache_lock); 247 rp = nfsrv_lookupcache(nd); 248 if (rp) { 249 simple_unlock(&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 simple_lock(&nfsrv_reqcache_lock); 254 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 255 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 256 simple_unlock(&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_flag & 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_flag & 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 simple_lock(&nfsrv_reqcache_lock); 279 nfsrv_unlockcache(rp); 280 simple_unlock(&nfsrv_reqcache_lock); 281 return ret; 282 } 283 nfsstats.srvcache_misses++; 284 if (numnfsrvcache < desirednfsrvcache) { 285 numnfsrvcache++; 286 simple_unlock(&nfsrv_reqcache_lock); 287 rp = pool_get(&nfs_reqcache_pool, PR_WAITOK); 288 memset(rp, 0, sizeof *rp); 289 rp->rc_flag = RC_LOCKED; 290 } else { 291 rp = TAILQ_FIRST(&nfsrvlruhead); 292 while ((rp->rc_flag & RC_LOCKED) != 0) { 293 rp->rc_flag |= RC_WANTED; 294 (void) ltsleep(rp, PZERO-1, "nfsrc", 0, 295 &nfsrv_reqcache_lock); 296 rp = TAILQ_FIRST(&nfsrvlruhead); 297 } 298 rp->rc_flag |= RC_LOCKED; 299 LIST_REMOVE(rp, rc_hash); 300 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 301 simple_unlock(&nfsrv_reqcache_lock); 302 cleanentry(rp); 303 rp->rc_flag &= (RC_LOCKED | RC_WANTED); 304 } 305 rp->rc_state = RC_INPROG; 306 rp->rc_xid = nd->nd_retxid; 307 saddr = mtod(nd->nd_nam, struct sockaddr_in *); 308 switch (saddr->sin_family) { 309 case AF_INET: 310 rp->rc_flag |= RC_INETADDR; 311 rp->rc_inetaddr = saddr->sin_addr.s_addr; 312 break; 313 case AF_ISO: 314 default: 315 rp->rc_flag |= RC_NAM; 316 rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT); 317 m_claimm(rp->rc_nam, &nfsd_cache_mowner); 318 break; 319 }; 320 rp->rc_proc = nd->nd_procnum; 321 simple_lock(&nfsrv_reqcache_lock); 322 rpdup = nfsrv_lookupcache(nd); 323 if (rpdup != NULL) { 324 /* 325 * other thread made duplicate cache entry. 326 */ 327 simple_unlock(&nfsrv_reqcache_lock); 328 pool_put(&nfs_reqcache_pool, rp); 329 rp = rpdup; 330 goto found; 331 } 332 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru); 333 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash); 334 nfsrv_unlockcache(rp); 335 simple_unlock(&nfsrv_reqcache_lock); 336 return RC_DOIT; 337 } 338 339 /* 340 * Update a request cache entry after the rpc has been done 341 */ 342 void 343 nfsrv_updatecache(nd, repvalid, repmbuf) 344 struct nfsrv_descript *nd; 345 int repvalid; 346 struct mbuf *repmbuf; 347 { 348 struct nfsrvcache *rp; 349 350 simple_lock(&nfsrv_reqcache_lock); 351 rp = nfsrv_lookupcache(nd); 352 simple_unlock(&nfsrv_reqcache_lock); 353 if (rp) { 354 cleanentry(rp); 355 rp->rc_state = RC_DONE; 356 /* 357 * If we have a valid reply update status and save 358 * the reply for non-idempotent rpc's. 359 */ 360 if (repvalid && nonidempotent[nd->nd_procnum]) { 361 if ((nd->nd_flag & ND_NFSV3) == 0 && 362 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) { 363 rp->rc_status = nd->nd_repstat; 364 rp->rc_flag |= RC_REPSTATUS; 365 } else { 366 rp->rc_reply = m_copym(repmbuf, 367 0, M_COPYALL, M_WAIT); 368 m_claimm(rp->rc_reply, &nfsd_cache_mowner); 369 rp->rc_flag |= RC_REPMBUF; 370 } 371 } 372 simple_lock(&nfsrv_reqcache_lock); 373 nfsrv_unlockcache(rp); 374 simple_unlock(&nfsrv_reqcache_lock); 375 } 376 } 377 378 /* 379 * Clean out the cache. Called when the last nfsd terminates. 380 */ 381 void 382 nfsrv_cleancache() 383 { 384 struct nfsrvcache *rp, *nextrp; 385 386 simple_lock(&nfsrv_reqcache_lock); 387 for (rp = TAILQ_FIRST(&nfsrvlruhead); rp != 0; rp = nextrp) { 388 nextrp = TAILQ_NEXT(rp, rc_lru); 389 LIST_REMOVE(rp, rc_hash); 390 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru); 391 KASSERT((rp->rc_flag & (RC_LOCKED|RC_WANTED)) == 0); 392 cleanentry(rp); 393 pool_put(&nfs_reqcache_pool, rp); 394 } 395 numnfsrvcache = 0; 396 simple_unlock(&nfsrv_reqcache_lock); 397 } 398
Indexes created Tue Sep 23 22:09:46 GMT 2025