| 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 | |