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nfs_srvcache.c revision 1.22
      1 /*	$NetBSD: nfs_srvcache.c,v 1.22 2003/04/02 15:14:22 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 1.22 2003/04/02 15:14:22 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/mbuf.h>
     59 #include <sys/malloc.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/nqnfs.h>
     73 #include <nfs/nfs_var.h>
     74 
     75 extern struct nfsstats nfsstats;
     76 extern const int nfsv2_procid[NFS_NPROCS];
     77 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ;
     78 
     79 #define	NFSRCHASH(xid) \
     80 	(&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash])
     81 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl;
     82 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead;
     83 u_long nfsrvhash;
     84 
     85 #define TRUE	1
     86 #define	FALSE	0
     87 
     88 #define	NETFAMILY(rp) \
     89 		(((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO)
     90 
     91 /*
     92  * Static array that defines which nfs rpc's are nonidempotent
     93  */
     94 const int nonidempotent[NFS_NPROCS] = {
     95 	FALSE,
     96 	FALSE,
     97 	TRUE,
     98 	FALSE,
     99 	FALSE,
    100 	FALSE,
    101 	FALSE,
    102 	TRUE,
    103 	TRUE,
    104 	TRUE,
    105 	TRUE,
    106 	TRUE,
    107 	TRUE,
    108 	TRUE,
    109 	TRUE,
    110 	TRUE,
    111 	FALSE,
    112 	FALSE,
    113 	FALSE,
    114 	FALSE,
    115 	FALSE,
    116 	FALSE,
    117 	FALSE,
    118 	FALSE,
    119 	FALSE,
    120 	FALSE,
    121 };
    122 
    123 /* True iff the rpc reply is an nfs status ONLY! */
    124 static const int nfsv2_repstat[NFS_NPROCS] = {
    125 	FALSE,
    126 	FALSE,
    127 	FALSE,
    128 	FALSE,
    129 	FALSE,
    130 	FALSE,
    131 	FALSE,
    132 	FALSE,
    133 	FALSE,
    134 	FALSE,
    135 	TRUE,
    136 	TRUE,
    137 	TRUE,
    138 	TRUE,
    139 	FALSE,
    140 	TRUE,
    141 	FALSE,
    142 	FALSE,
    143 };
    144 
    145 /*
    146  * Initialize the server request cache list
    147  */
    148 void
    149 nfsrv_initcache()
    150 {
    151 
    152 	nfsrvhashtbl = hashinit(desirednfsrvcache, HASH_LIST, M_NFSD,
    153 	    M_WAITOK, &nfsrvhash);
    154 	TAILQ_INIT(&nfsrvlruhead);
    155 }
    156 
    157 /*
    158  * Look for the request in the cache
    159  * If found then
    160  *    return action and optionally reply
    161  * else
    162  *    insert it in the cache
    163  *
    164  * The rules are as follows:
    165  * - if in progress, return DROP request
    166  * - if completed within DELAY of the current time, return DROP it
    167  * - if completed a longer time ago return REPLY if the reply was cached or
    168  *   return DOIT
    169  * Update/add new request at end of lru list
    170  */
    171 int
    172 nfsrv_getcache(nd, slp, repp)
    173 	struct nfsrv_descript *nd;
    174 	struct nfssvc_sock *slp;
    175 	struct mbuf **repp;
    176 {
    177 	struct nfsrvcache *rp;
    178 	struct mbuf *mb;
    179 	struct sockaddr_in *saddr;
    180 	caddr_t bpos;
    181 	int ret;
    182 
    183 	/*
    184 	 * Don't cache recent requests for reliable transport protocols.
    185 	 * (Maybe we should for the case of a reconnect, but..)
    186 	 */
    187 	if (!nd->nd_nam2)
    188 		return (RC_DOIT);
    189 loop:
    190 	LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
    191 	    if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
    192 		netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
    193 			if ((rp->rc_flag & RC_LOCKED) != 0) {
    194 				rp->rc_flag |= RC_WANTED;
    195 				(void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
    196 				goto loop;
    197 			}
    198 			rp->rc_flag |= RC_LOCKED;
    199 			/* If not at end of LRU chain, move it there */
    200 			if (TAILQ_NEXT(rp, rc_lru)) {
    201 				TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
    202 				TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
    203 			}
    204 			if (rp->rc_state == RC_UNUSED)
    205 				panic("nfsrv cache");
    206 			if (rp->rc_state == RC_INPROG) {
    207 				nfsstats.srvcache_inproghits++;
    208 				ret = RC_DROPIT;
    209 			} else if (rp->rc_flag & RC_REPSTATUS) {
    210 				nfsstats.srvcache_nonidemdonehits++;
    211 				nfs_rephead(0, nd, slp, rp->rc_status,
    212 				   0, (u_quad_t *)0, repp, &mb, &bpos);
    213 				ret = RC_REPLY;
    214 			} else if (rp->rc_flag & RC_REPMBUF) {
    215 				nfsstats.srvcache_nonidemdonehits++;
    216 				*repp = m_copym(rp->rc_reply, 0, M_COPYALL,
    217 						M_WAIT);
    218 				ret = RC_REPLY;
    219 			} else {
    220 				nfsstats.srvcache_idemdonehits++;
    221 				rp->rc_state = RC_INPROG;
    222 				ret = RC_DOIT;
    223 			}
    224 			rp->rc_flag &= ~RC_LOCKED;
    225 			if (rp->rc_flag & RC_WANTED) {
    226 				rp->rc_flag &= ~RC_WANTED;
    227 				wakeup((caddr_t)rp);
    228 			}
    229 			return (ret);
    230 		}
    231 	}
    232 	nfsstats.srvcache_misses++;
    233 	if (numnfsrvcache < desirednfsrvcache) {
    234 		rp = (struct nfsrvcache *)malloc((u_long)sizeof *rp,
    235 		    M_NFSD, M_WAITOK);
    236 		memset((char *)rp, 0, sizeof *rp);
    237 		numnfsrvcache++;
    238 		rp->rc_flag = RC_LOCKED;
    239 	} else {
    240 		rp = TAILQ_FIRST(&nfsrvlruhead);
    241 		while ((rp->rc_flag & RC_LOCKED) != 0) {
    242 			rp->rc_flag |= RC_WANTED;
    243 			(void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
    244 			rp = TAILQ_FIRST(&nfsrvlruhead);
    245 		}
    246 		rp->rc_flag |= RC_LOCKED;
    247 		LIST_REMOVE(rp, rc_hash);
    248 		TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
    249 		if (rp->rc_flag & RC_REPMBUF)
    250 			m_freem(rp->rc_reply);
    251 		if (rp->rc_flag & RC_NAM)
    252 			(void) m_free(rp->rc_nam);
    253 		rp->rc_flag &= (RC_LOCKED | RC_WANTED);
    254 	}
    255 	TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
    256 	rp->rc_state = RC_INPROG;
    257 	rp->rc_xid = nd->nd_retxid;
    258 	saddr = mtod(nd->nd_nam, struct sockaddr_in *);
    259 	switch (saddr->sin_family) {
    260 	case AF_INET:
    261 		rp->rc_flag |= RC_INETADDR;
    262 		rp->rc_inetaddr = saddr->sin_addr.s_addr;
    263 		break;
    264 	case AF_ISO:
    265 	default:
    266 		rp->rc_flag |= RC_NAM;
    267 		rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT);
    268 		break;
    269 	};
    270 	rp->rc_proc = nd->nd_procnum;
    271 	LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
    272 	rp->rc_flag &= ~RC_LOCKED;
    273 	if (rp->rc_flag & RC_WANTED) {
    274 		rp->rc_flag &= ~RC_WANTED;
    275 		wakeup((caddr_t)rp);
    276 	}
    277 	return (RC_DOIT);
    278 }
    279 
    280 /*
    281  * Update a request cache entry after the rpc has been done
    282  */
    283 void
    284 nfsrv_updatecache(nd, repvalid, repmbuf)
    285 	struct nfsrv_descript *nd;
    286 	int repvalid;
    287 	struct mbuf *repmbuf;
    288 {
    289 	struct nfsrvcache *rp;
    290 
    291 	if (!nd->nd_nam2)
    292 		return;
    293 loop:
    294 	LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
    295 	    if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
    296 		netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
    297 			if ((rp->rc_flag & RC_LOCKED) != 0) {
    298 				rp->rc_flag |= RC_WANTED;
    299 				(void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
    300 				goto loop;
    301 			}
    302 			rp->rc_flag |= RC_LOCKED;
    303 			rp->rc_state = RC_DONE;
    304 			/*
    305 			 * If we have a valid reply update status and save
    306 			 * the reply for non-idempotent rpc's.
    307 			 */
    308 			if (repvalid && nonidempotent[nd->nd_procnum]) {
    309 				if ((nd->nd_flag & ND_NFSV3) == 0 &&
    310 				  nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) {
    311 					rp->rc_status = nd->nd_repstat;
    312 					rp->rc_flag |= RC_REPSTATUS;
    313 				} else {
    314 					rp->rc_reply = m_copym(repmbuf,
    315 						0, M_COPYALL, M_WAIT);
    316 					rp->rc_flag |= RC_REPMBUF;
    317 				}
    318 			}
    319 			rp->rc_flag &= ~RC_LOCKED;
    320 			if (rp->rc_flag & RC_WANTED) {
    321 				rp->rc_flag &= ~RC_WANTED;
    322 				wakeup((caddr_t)rp);
    323 			}
    324 			return;
    325 		}
    326 	}
    327 }
    328 
    329 /*
    330  * Clean out the cache. Called when the last nfsd terminates.
    331  */
    332 void
    333 nfsrv_cleancache()
    334 {
    335 	struct nfsrvcache *rp, *nextrp;
    336 
    337 	for (rp = TAILQ_FIRST(&nfsrvlruhead); rp != 0; rp = nextrp) {
    338 		nextrp = TAILQ_NEXT(rp, rc_lru);
    339 		LIST_REMOVE(rp, rc_hash);
    340 		TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
    341 		free(rp, M_NFSD);
    342 	}
    343 	numnfsrvcache = 0;
    344 }
    345