bsd/nfs/nfs_srvcache.c

   1 /*
   2  * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1989, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * This code is derived from software contributed to Berkeley by
  34  * Rick Macklem at The University of Guelph.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. All advertising materials mentioning features or use of this software
  45  *    must display the following acknowledgement:
  46  *      This product includes software developed by the University of
  47  *      California, Berkeley and its contributors.
  48  * 4. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  *
  64  *      @(#)nfs_srvcache.c      8.3 (Berkeley) 3/30/95
  65  * FreeBSD-Id: nfs_srvcache.c,v 1.15 1997/10/12 20:25:46 phk Exp $
  66  */
  67
  68 #if NFSSERVER
  69 /*
  70  * Reference: Chet Juszczak, "Improving the Performance and Correctness
  71  *              of an NFS Server", in Proc. Winter 1989 USENIX Conference,
  72  *              pages 53-63. San Diego, February 1989.
  73  */
  74 #include <sys/param.h>
  75 #include <sys/vnode.h>
  76 #include <sys/mount_internal.h>
  77 #include <sys/kernel.h>
  78 #include <sys/systm.h>
  79 #include <sys/proc.h>
  80 #include <sys/kpi_mbuf.h>
  81 #include <sys/malloc.h>
  82 #include <sys/socket.h>
  83 #include <libkern/OSAtomic.h>
  84
  85 #include <netinet/in.h>
  86 #include <nfs/rpcv2.h>
  87 #include <nfs/nfsproto.h>
  88 #include <nfs/nfs.h>
  89 #include <nfs/nfsrvcache.h>
  90
  91 extern int nfsv2_procid[NFS_NPROCS];
  92 static int nfsrv_reqcache_count;
  93 int nfsrv_reqcache_size = NFSRVCACHESIZ;
  94
  95 #define NFSRCHASH(xid) \
  96         (&nfsrv_reqcache_hashtbl[((xid) + ((xid) >> 24)) & nfsrv_reqcache_hash])
  97 LIST_HEAD(nfsrv_reqcache_hash, nfsrvcache) *nfsrv_reqcache_hashtbl;
  98 TAILQ_HEAD(nfsrv_reqcache_lru, nfsrvcache) nfsrv_reqcache_lruhead;
  99 u_long nfsrv_reqcache_hash;
 100
 101 lck_grp_t *nfsrv_reqcache_lck_grp;
 102 lck_mtx_t *nfsrv_reqcache_mutex;
 103
 104 /*
 105  * Static array that defines which nfs rpc's are nonidempotent
 106  */
 107 static int nonidempotent[NFS_NPROCS] = {
 108         FALSE,
 109         FALSE,
 110         TRUE,
 111         FALSE,
 112         FALSE,
 113         FALSE,
 114         FALSE,
 115         TRUE,
 116         TRUE,
 117         TRUE,
 118         TRUE,
 119         TRUE,
 120         TRUE,
 121         TRUE,
 122         TRUE,
 123         TRUE,
 124         FALSE,
 125         FALSE,
 126         FALSE,
 127         FALSE,
 128         FALSE,
 129         FALSE,
 130         FALSE,
 131 };
 132
 133 /* True iff the rpc reply is an nfs status ONLY! */
 134 static int nfsv2_repstat[NFS_NPROCS] = {
 135         FALSE,
 136         FALSE,
 137         FALSE,
 138         FALSE,
 139         FALSE,
 140         FALSE,
 141         FALSE,
 142         FALSE,
 143         FALSE,
 144         FALSE,
 145         TRUE,
 146         TRUE,
 147         TRUE,
 148         TRUE,
 149         FALSE,
 150         TRUE,
 151         FALSE,
 152         FALSE,
 153 };
 154
 155 /*
 156  * Initialize the server request cache list
 157  */
 158 void
 159 nfsrv_initcache(void)
 160 {
 161         if (nfsrv_reqcache_size <= 0)
 162                 return;
 163
 164         lck_mtx_lock(nfsrv_reqcache_mutex);
 165         /* init nfs server request cache hash table */
 166         nfsrv_reqcache_hashtbl = hashinit(nfsrv_reqcache_size, M_NFSD, &nfsrv_reqcache_hash);
 167         TAILQ_INIT(&nfsrv_reqcache_lruhead);
 168         lck_mtx_unlock(nfsrv_reqcache_mutex);
 169 }
 170
 171 /*
 172  * This function compares two net addresses by family and returns TRUE
 173  * if they are the same host.
 174  * If there is any doubt, return FALSE.
 175  * The AF_INET family is handled as a special case so that address mbufs
 176  * don't need to be saved to store "struct in_addr", which is only 4 bytes.
 177  * Ditto for AF_INET6 which is only 16 bytes.
 178  */
 179 static int
 180 netaddr_match(
 181         int family,
 182         union nethostaddr *haddr,
 183         mbuf_t nam)
 184 {
 185         struct sockaddr_in *inetaddr;
 186         struct sockaddr_in6 *inet6addr;
 187
 188         switch (family) {
 189         case AF_INET:
 190                 inetaddr = mbuf_data(nam);
 191                 if ((inetaddr->sin_family == AF_INET) &&
 192                     (inetaddr->sin_addr.s_addr == haddr->had_inetaddr))
 193                         return (1);
 194                 break;
 195         case AF_INET6:
 196                 inet6addr = mbuf_data(nam);
 197                 if ((inet6addr->sin6_family == AF_INET6) &&
 198                     !bcmp(&inet6addr->sin6_addr, &haddr->had_inet6addr, sizeof(inet6addr->sin6_addr)))
 199                         return (1);
 200                 break;
 201         }
 202         return (0);
 203 }
 204
 205 /*
 206  * Look for the request in the cache
 207  * If found then
 208  *    return action and optionally reply
 209  * else
 210  *    insert it in the cache
 211  *
 212  * The rules are as follows:
 213  * - if in progress, return DROP request
 214  * - if completed within DELAY of the current time, return DROP it
 215  * - if completed a longer time ago return REPLY if the reply was cached or
 216  *   return DOIT
 217  * Update/add new request at end of lru list
 218  */
 219 int
 220 nfsrv_getcache(
 221         struct nfsrv_descript *nd,
 222         struct nfsrv_sock *slp,
 223         mbuf_t *mrepp)
 224 {
 225         struct nfsrvcache *rp;
 226         struct nfsm_chain nmrep;
 227         struct sockaddr *saddr;
 228         int ret, error;
 229
 230         /*
 231          * Don't cache recent requests for reliable transport protocols.
 232          * (Maybe we should for the case of a reconnect, but..)
 233          */
 234         if (!nd->nd_nam2)
 235                 return (RC_DOIT);
 236         lck_mtx_lock(nfsrv_reqcache_mutex);
 237 loop:
 238         for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0;
 239             rp = rp->rc_hash.le_next) {
 240             if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
 241                 netaddr_match(rp->rc_family, &rp->rc_haddr, nd->nd_nam)) {
 242                         if ((rp->rc_flag & RC_LOCKED) != 0) {
 243                                 rp->rc_flag |= RC_WANTED;
 244                                 msleep(rp, nfsrv_reqcache_mutex, PZERO-1, "nfsrc", NULL);
 245                                 goto loop;
 246                         }
 247                         rp->rc_flag |= RC_LOCKED;
 248                         /* If not at end of LRU chain, move it there */
 249                         if (rp->rc_lru.tqe_next) {
 250                                 TAILQ_REMOVE(&nfsrv_reqcache_lruhead, rp, rc_lru);
 251                                 TAILQ_INSERT_TAIL(&nfsrv_reqcache_lruhead, rp, rc_lru);
 252                         }
 253                         if (rp->rc_state == RC_UNUSED)
 254                                 panic("nfsrv cache");
 255                         if (rp->rc_state == RC_INPROG) {
 256                                 OSAddAtomic(1, &nfsstats.srvcache_inproghits);
 257                                 ret = RC_DROPIT;
 258                         } else if (rp->rc_flag & RC_REPSTATUS) {
 259                                 OSAddAtomic(1, &nfsstats.srvcache_nonidemdonehits);
 260                                 nd->nd_repstat = rp->rc_status;
 261                                 error = nfsrv_rephead(nd, slp, &nmrep, 0);
 262                                 if (error) {
 263                                         printf("nfsrv cache: reply alloc failed for nonidem request hit\n");
 264                                         ret = RC_DROPIT;
 265                                         *mrepp = NULL;
 266                                 } else {
 267                                         ret = RC_REPLY;
 268                                         *mrepp = nmrep.nmc_mhead;
 269                                 }
 270                         } else if (rp->rc_flag & RC_REPMBUF) {
 271                                 OSAddAtomic(1, &nfsstats.srvcache_nonidemdonehits);
 272                                 error = mbuf_copym(rp->rc_reply, 0, MBUF_COPYALL, MBUF_WAITOK, mrepp);
 273                                 if (error) {
 274                                         printf("nfsrv cache: reply copym failed for nonidem request hit\n");
 275                                         ret = RC_DROPIT;
 276                                 } else {
 277                                         ret = RC_REPLY;
 278                                 }
 279                         } else {
 280                                 OSAddAtomic(1, &nfsstats.srvcache_idemdonehits);
 281                                 rp->rc_state = RC_INPROG;
 282                                 ret = RC_DOIT;
 283                         }
 284                         rp->rc_flag &= ~RC_LOCKED;
 285                         if (rp->rc_flag & RC_WANTED) {
 286                                 rp->rc_flag &= ~RC_WANTED;
 287                                 wakeup(rp);
 288                         }
 289                         lck_mtx_unlock(nfsrv_reqcache_mutex);
 290                         return (ret);
 291                 }
 292         }
 293         OSAddAtomic(1, &nfsstats.srvcache_misses);
 294         if (nfsrv_reqcache_count < nfsrv_reqcache_size) {
 295                 /* try to allocate a new entry */
 296                 MALLOC(rp, struct nfsrvcache *, sizeof *rp, M_NFSD, M_WAITOK);
 297                 if (rp) {
 298                         bzero((char *)rp, sizeof *rp);
 299                         nfsrv_reqcache_count++;
 300                         rp->rc_flag = RC_LOCKED;
 301                 }
 302         } else {
 303                 rp = NULL;
 304         }
 305         if (!rp) {
 306                 /* try to reuse the least recently used entry */
 307                 rp = nfsrv_reqcache_lruhead.tqh_first;
 308                 if (!rp) {
 309                         /* no entry to reuse? */
 310                         /* OK, we just won't be able to cache this request */
 311                         lck_mtx_unlock(nfsrv_reqcache_mutex);
 312                         return (RC_DOIT);
 313                 }
 314                 while ((rp->rc_flag & RC_LOCKED) != 0) {
 315                         rp->rc_flag |= RC_WANTED;
 316                         msleep(rp, nfsrv_reqcache_mutex, PZERO-1, "nfsrc", NULL);
 317                         rp = nfsrv_reqcache_lruhead.tqh_first;
 318                 }
 319                 rp->rc_flag |= RC_LOCKED;
 320                 LIST_REMOVE(rp, rc_hash);
 321                 TAILQ_REMOVE(&nfsrv_reqcache_lruhead, rp, rc_lru);
 322                 if (rp->rc_flag & RC_REPMBUF)
 323                         mbuf_freem(rp->rc_reply);
 324                 if (rp->rc_flag & RC_NAM)
 325                         mbuf_freem(rp->rc_nam);
 326                 rp->rc_flag &= (RC_LOCKED | RC_WANTED);
 327         }
 328         TAILQ_INSERT_TAIL(&nfsrv_reqcache_lruhead, rp, rc_lru);
 329         rp->rc_state = RC_INPROG;
 330         rp->rc_xid = nd->nd_retxid;
 331         saddr = mbuf_data(nd->nd_nam);
 332         rp->rc_family = saddr->sa_family;
 333         switch (saddr->sa_family) {
 334         case AF_INET:
 335                 rp->rc_flag |= RC_INETADDR;
 336                 rp->rc_inetaddr = ((struct sockaddr_in*)saddr)->sin_addr.s_addr;
 337                 break;
 338         case AF_INET6:
 339                 rp->rc_flag |= RC_INETADDR;
 340                 rp->rc_inet6addr = ((struct sockaddr_in6*)saddr)->sin6_addr;
 341                 break;
 342         default:
 343                 error = mbuf_copym(nd->nd_nam, 0, MBUF_COPYALL, MBUF_WAITOK, &rp->rc_nam);
 344                 if (error)
 345                         printf("nfsrv cache: nam copym failed\n");
 346                 else
 347                         rp->rc_flag |= RC_NAM;
 348                 break;
 349         };
 350         rp->rc_proc = nd->nd_procnum;
 351         LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
 352         rp->rc_flag &= ~RC_LOCKED;
 353         if (rp->rc_flag & RC_WANTED) {
 354                 rp->rc_flag &= ~RC_WANTED;
 355                 wakeup(rp);
 356         }
 357         lck_mtx_unlock(nfsrv_reqcache_mutex);
 358         return (RC_DOIT);
 359 }
 360
 361 /*
 362  * Update a request cache entry after the rpc has been done
 363  */
 364 void
 365 nfsrv_updatecache(
 366         struct nfsrv_descript *nd,
 367         int repvalid,
 368         mbuf_t repmbuf)
 369 {
 370         struct nfsrvcache *rp;
 371         int error;
 372
 373         if (!nd->nd_nam2)
 374                 return;
 375         lck_mtx_lock(nfsrv_reqcache_mutex);
 376 loop:
 377         for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0;
 378             rp = rp->rc_hash.le_next) {
 379             if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
 380                 netaddr_match(rp->rc_family, &rp->rc_haddr, nd->nd_nam)) {
 381                         if ((rp->rc_flag & RC_LOCKED) != 0) {
 382                                 rp->rc_flag |= RC_WANTED;
 383                                 msleep(rp, nfsrv_reqcache_mutex, PZERO-1, "nfsrc", NULL);
 384                                 goto loop;
 385                         }
 386                         rp->rc_flag |= RC_LOCKED;
 387                         if (rp->rc_state == RC_DONE) {
 388                                 /*
 389                                  * This can occur if the cache is too small.
 390                                  * Retransmits of the same request aren't
 391                                  * dropped so we may see the operation
 392                                  * complete more then once.
 393                                  */
 394                                 if (rp->rc_flag & RC_REPMBUF) {
 395                                         mbuf_freem(rp->rc_reply);
 396                                         rp->rc_flag &= ~RC_REPMBUF;
 397                                 }
 398                         }
 399                         rp->rc_state = RC_DONE;
 400                         /*
 401                          * If we have a valid reply update status and save
 402                          * the reply for non-idempotent rpc's.
 403                          */
 404                         if (repvalid && nonidempotent[nd->nd_procnum]) {
 405                                 if ((nd->nd_vers == NFS_VER2) &&
 406                                   nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) {
 407                                         rp->rc_status = nd->nd_repstat;
 408                                         rp->rc_flag |= RC_REPSTATUS;
 409                                 } else {
 410                                         error = mbuf_copym(repmbuf, 0, MBUF_COPYALL, MBUF_WAITOK, &rp->rc_reply);
 411                                         if (!error)
 412                                                 rp->rc_flag |= RC_REPMBUF;
 413                                 }
 414                         }
 415                         rp->rc_flag &= ~RC_LOCKED;
 416                         if (rp->rc_flag & RC_WANTED) {
 417                                 rp->rc_flag &= ~RC_WANTED;
 418                                 wakeup(rp);
 419                         }
 420                         lck_mtx_unlock(nfsrv_reqcache_mutex);
 421                         return;
 422                 }
 423         }
 424         lck_mtx_unlock(nfsrv_reqcache_mutex);
 425 }
 426
 427 /*
 428  * Clean out the cache. Called when the last nfsd terminates.
 429  */
 430 void
 431 nfsrv_cleancache(void)
 432 {
 433         struct nfsrvcache *rp, *nextrp;
 434
 435         lck_mtx_lock(nfsrv_reqcache_mutex);
 436         for (rp = nfsrv_reqcache_lruhead.tqh_first; rp != 0; rp = nextrp) {
 437                 nextrp = rp->rc_lru.tqe_next;
 438                 LIST_REMOVE(rp, rc_hash);
 439                 TAILQ_REMOVE(&nfsrv_reqcache_lruhead, rp, rc_lru);
 440                 _FREE(rp, M_NFSD);
 441         }
 442         nfsrv_reqcache_count = 0;
 443         FREE(nfsrv_reqcache_hashtbl, M_TEMP);
 444         lck_mtx_unlock(nfsrv_reqcache_mutex);
 445 }
 446
 447 #endif /* NFSSERVER */