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nfs_srvcache.c revision 1.25
      1 /*	$NetBSD: nfs_srvcache.c,v 1.25 2003/05/21 13:55:28 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. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  *	@(#)nfs_srvcache.c	8.3 (Berkeley) 3/30/95
     39  */
     40 
     41 /*
     42  * Reference: Chet Juszczak, "Improving the Performance and Correctness
     43  *		of an NFS Server", in Proc. Winter 1989 USENIX Conference,
     44  *		pages 53-63. San Diego, February 1989.
     45  */
     46 
     47 #include <sys/cdefs.h>
     48 __KERNEL_RCSID(0, "$NetBSD: nfs_srvcache.c,v 1.25 2003/05/21 13:55:28 yamt Exp $");
     49 
     50 #include "opt_iso.h"
     51 
     52 #include <sys/param.h>
     53 #include <sys/vnode.h>
     54 #include <sys/mount.h>
     55 #include <sys/kernel.h>
     56 #include <sys/systm.h>
     57 #include <sys/proc.h>
     58 #include <sys/pool.h>
     59 #include <sys/mbuf.h>
     60 #include <sys/malloc.h>
     61 #include <sys/socket.h>
     62 #include <sys/socketvar.h>
     63 
     64 #include <netinet/in.h>
     65 #ifdef ISO
     66 #include <netiso/iso.h>
     67 #endif
     68 #include <nfs/nfsm_subs.h>
     69 #include <nfs/rpcv2.h>
     70 #include <nfs/nfsproto.h>
     71 #include <nfs/nfs.h>
     72 #include <nfs/nfsrvcache.h>
     73 #include <nfs/nqnfs.h>
     74 #include <nfs/nfs_var.h>
     75 
     76 extern struct nfsstats nfsstats;
     77 extern const int nfsv2_procid[NFS_NPROCS];
     78 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ;
     79 struct pool nfs_reqcache_pool;
     80 
     81 #define	NFSRCHASH(xid) \
     82 	(&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash])
     83 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl;
     84 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead;
     85 u_long nfsrvhash;
     86 
     87 #define	NETFAMILY(rp) \
     88 		(((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO)
     89 
     90 /*
     91  * Static array that defines which nfs rpc's are nonidempotent
     92  */
     93 const int nonidempotent[NFS_NPROCS] = {
     94 	FALSE,
     95 	FALSE,
     96 	TRUE,
     97 	FALSE,
     98 	FALSE,
     99 	FALSE,
    100 	FALSE,
    101 	TRUE,
    102 	TRUE,
    103 	TRUE,
    104 	TRUE,
    105 	TRUE,
    106 	TRUE,
    107 	TRUE,
    108 	TRUE,
    109 	TRUE,
    110 	FALSE,
    111 	FALSE,
    112 	FALSE,
    113 	FALSE,
    114 	FALSE,
    115 	FALSE,
    116 	FALSE,
    117 	FALSE,
    118 	FALSE,
    119 	FALSE,
    120 };
    121 
    122 /* True iff the rpc reply is an nfs status ONLY! */
    123 static const int nfsv2_repstat[NFS_NPROCS] = {
    124 	FALSE,
    125 	FALSE,
    126 	FALSE,
    127 	FALSE,
    128 	FALSE,
    129 	FALSE,
    130 	FALSE,
    131 	FALSE,
    132 	FALSE,
    133 	FALSE,
    134 	TRUE,
    135 	TRUE,
    136 	TRUE,
    137 	TRUE,
    138 	FALSE,
    139 	TRUE,
    140 	FALSE,
    141 	FALSE,
    142 };
    143 
    144 /*
    145  * Initialize the server request cache list
    146  */
    147 void
    148 nfsrv_initcache()
    149 {
    150 
    151 	nfsrvhashtbl = hashinit(desirednfsrvcache, HASH_LIST, M_NFSD,
    152 	    M_WAITOK, &nfsrvhash);
    153 	TAILQ_INIT(&nfsrvlruhead);
    154 	pool_init(&nfs_reqcache_pool, sizeof(struct nfsrvcache), 0, 0, 0,
    155 	    "nfsreqcachepl", &pool_allocator_nointr);
    156 }
    157 
    158 /*
    159  * Look for the request in the cache
    160  * If found then
    161  *    return action and optionally reply
    162  * else
    163  *    insert it in the cache
    164  *
    165  * The rules are as follows:
    166  * - if in progress, return DROP request
    167  * - if completed within DELAY of the current time, return DROP it
    168  * - if completed a longer time ago return REPLY if the reply was cached or
    169  *   return DOIT
    170  * Update/add new request at end of lru list
    171  */
    172 int
    173 nfsrv_getcache(nd, slp, repp)
    174 	struct nfsrv_descript *nd;
    175 	struct nfssvc_sock *slp;
    176 	struct mbuf **repp;
    177 {
    178 	struct nfsrvcache *rp;
    179 	struct mbuf *mb;
    180 	struct sockaddr_in *saddr;
    181 	caddr_t bpos;
    182 	int ret;
    183 
    184 	/*
    185 	 * Don't cache recent requests for reliable transport protocols.
    186 	 * (Maybe we should for the case of a reconnect, but..)
    187 	 */
    188 	if (!nd->nd_nam2)
    189 		return (RC_DOIT);
    190 loop:
    191 	LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
    192 		if (nd->nd_retxid == rp->rc_xid &&
    193 		    nd->nd_procnum == rp->rc_proc &&
    194 		    netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
    195 			if ((rp->rc_flag & RC_LOCKED) != 0) {
    196 				rp->rc_flag |= RC_WANTED;
    197 				(void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
    198 				goto loop;
    199 			}
    200 			rp->rc_flag |= RC_LOCKED;
    201 			/* If not at end of LRU chain, move it there */
    202 			if (TAILQ_NEXT(rp, rc_lru)) {
    203 				TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
    204 				TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
    205 			}
    206 			if (rp->rc_state == RC_UNUSED)
    207 				panic("nfsrv cache");
    208 			if (rp->rc_state == RC_INPROG) {
    209 				nfsstats.srvcache_inproghits++;
    210 				ret = RC_DROPIT;
    211 			} else if (rp->rc_flag & RC_REPSTATUS) {
    212 				nfsstats.srvcache_nonidemdonehits++;
    213 				nfs_rephead(0, nd, slp, rp->rc_status,
    214 				   0, (u_quad_t *)0, repp, &mb, &bpos);
    215 				ret = RC_REPLY;
    216 			} else if (rp->rc_flag & RC_REPMBUF) {
    217 				nfsstats.srvcache_nonidemdonehits++;
    218 				*repp = m_copym(rp->rc_reply, 0, M_COPYALL,
    219 						M_WAIT);
    220 				ret = RC_REPLY;
    221 			} else {
    222 				nfsstats.srvcache_idemdonehits++;
    223 				rp->rc_state = RC_INPROG;
    224 				ret = RC_DOIT;
    225 			}
    226 			rp->rc_flag &= ~RC_LOCKED;
    227 			if (rp->rc_flag & RC_WANTED) {
    228 				rp->rc_flag &= ~RC_WANTED;
    229 				wakeup((caddr_t)rp);
    230 			}
    231 			return (ret);
    232 		}
    233 	}
    234 	nfsstats.srvcache_misses++;
    235 	if (numnfsrvcache < desirednfsrvcache) {
    236 		rp = pool_get(&nfs_reqcache_pool, PR_WAITOK);
    237 		memset((char *)rp, 0, sizeof *rp);
    238 		numnfsrvcache++;
    239 		rp->rc_flag = RC_LOCKED;
    240 	} else {
    241 		rp = TAILQ_FIRST(&nfsrvlruhead);
    242 		while ((rp->rc_flag & RC_LOCKED) != 0) {
    243 			rp->rc_flag |= RC_WANTED;
    244 			(void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
    245 			rp = TAILQ_FIRST(&nfsrvlruhead);
    246 		}
    247 		rp->rc_flag |= RC_LOCKED;
    248 		LIST_REMOVE(rp, rc_hash);
    249 		TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
    250 		if (rp->rc_flag & RC_REPMBUF)
    251 			m_freem(rp->rc_reply);
    252 		if (rp->rc_flag & RC_NAM)
    253 			(void) m_free(rp->rc_nam);
    254 		rp->rc_flag &= (RC_LOCKED | RC_WANTED);
    255 	}
    256 	TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
    257 	rp->rc_state = RC_INPROG;
    258 	rp->rc_xid = nd->nd_retxid;
    259 	saddr = mtod(nd->nd_nam, struct sockaddr_in *);
    260 	switch (saddr->sin_family) {
    261 	case AF_INET:
    262 		rp->rc_flag |= RC_INETADDR;
    263 		rp->rc_inetaddr = saddr->sin_addr.s_addr;
    264 		break;
    265 	case AF_ISO:
    266 	default:
    267 		rp->rc_flag |= RC_NAM;
    268 		rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT);
    269 		break;
    270 	};
    271 	rp->rc_proc = nd->nd_procnum;
    272 	LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
    273 	rp->rc_flag &= ~RC_LOCKED;
    274 	if (rp->rc_flag & RC_WANTED) {
    275 		rp->rc_flag &= ~RC_WANTED;
    276 		wakeup((caddr_t)rp);
    277 	}
    278 	return (RC_DOIT);
    279 }
    280 
    281 /*
    282  * Update a request cache entry after the rpc has been done
    283  */
    284 void
    285 nfsrv_updatecache(nd, repvalid, repmbuf)
    286 	struct nfsrv_descript *nd;
    287 	int repvalid;
    288 	struct mbuf *repmbuf;
    289 {
    290 	struct nfsrvcache *rp;
    291 
    292 	if (!nd->nd_nam2)
    293 		return;
    294 loop:
    295 	LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
    296 		if (nd->nd_retxid == rp->rc_xid &&
    297 		    nd->nd_procnum == rp->rc_proc &&
    298 		    netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
    299 			if ((rp->rc_flag & RC_LOCKED) != 0) {
    300 				rp->rc_flag |= RC_WANTED;
    301 				(void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
    302 				goto loop;
    303 			}
    304 			rp->rc_flag |= RC_LOCKED;
    305 			rp->rc_state = RC_DONE;
    306 			/*
    307 			 * If we have a valid reply update status and save
    308 			 * the reply for non-idempotent rpc's.
    309 			 */
    310 			if (repvalid && nonidempotent[nd->nd_procnum]) {
    311 				if ((nd->nd_flag & ND_NFSV3) == 0 &&
    312 				  nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) {
    313 					rp->rc_status = nd->nd_repstat;
    314 					rp->rc_flag |= RC_REPSTATUS;
    315 				} else {
    316 					rp->rc_reply = m_copym(repmbuf,
    317 						0, M_COPYALL, M_WAIT);
    318 					rp->rc_flag |= RC_REPMBUF;
    319 				}
    320 			}
    321 			rp->rc_flag &= ~RC_LOCKED;
    322 			if (rp->rc_flag & RC_WANTED) {
    323 				rp->rc_flag &= ~RC_WANTED;
    324 				wakeup((caddr_t)rp);
    325 			}
    326 			return;
    327 		}
    328 	}
    329 }
    330 
    331 /*
    332  * Clean out the cache. Called when the last nfsd terminates.
    333  */
    334 void
    335 nfsrv_cleancache()
    336 {
    337 	struct nfsrvcache *rp, *nextrp;
    338 
    339 	for (rp = TAILQ_FIRST(&nfsrvlruhead); rp != 0; rp = nextrp) {
    340 		nextrp = TAILQ_NEXT(rp, rc_lru);
    341 		LIST_REMOVE(rp, rc_hash);
    342 		TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
    343 		pool_put(&nfs_reqcache_pool, rp);
    344 	}
    345 	numnfsrvcache = 0;
    346 }
    347