2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Rick Macklem at The University of Guelph.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95
37 * $FreeBSD: src/sys/nfs/nfs_srvcache.c,v 1.21 2000/02/13 03:32:06 peter Exp $
38 * $DragonFly: src/sys/vfs/nfs/nfs_srvcache.c,v 1.13 2008/01/05 14:02:41 swildner Exp $
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.
46 #include <sys/param.h>
47 #include <sys/malloc.h>
48 #include <sys/mount.h>
49 #include <sys/systm.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h> /* for dup_sockaddr */
54 #include <netinet/in.h>
58 #include "nfsrvcache.h"
61 extern struct nfsstats nfsstats;
62 extern int nfsv2_procid[NFS_NPROCS];
63 static long numnfsrvcache;
64 static long desirednfsrvcache = NFSRVCACHESIZ;
66 #define NFSRCHASH(xid) \
67 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash])
68 static LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl;
69 static TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead;
70 static u_long nfsrvhash;
75 #define NETFAMILY(rp) \
76 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO)
79 * Static array that defines which nfs rpc's are nonidempotent
81 static int nonidempotent[NFS_NPROCS] = {
110 /* True iff the rpc reply is an nfs status ONLY! */
111 static int nfsv2_repstat[NFS_NPROCS] = {
133 * Initialize the server request cache list
136 nfsrv_initcache(void)
139 nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, &nfsrvhash);
140 TAILQ_INIT(&nfsrvlruhead);
144 * Look for the request in the cache
146 * return action and optionally reply
148 * insert it in the cache
150 * The rules are as follows:
151 * - if in progress, return DROP request
152 * - if completed within DELAY of the current time, return DROP it
153 * - if completed a longer time ago return REPLY if the reply was cached or
155 * Update/add new request at end of lru list
158 nfsrv_getcache(struct nfsrv_descript *nd, struct nfssvc_sock *slp,
161 struct nfsrvcache *rp;
163 struct sockaddr_in *saddr;
168 * Don't cache recent requests for reliable transport protocols.
169 * (Maybe we should for the case of a reconnect, but..)
174 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0;
175 rp = rp->rc_hash.le_next) {
176 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
177 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
178 NFS_DPF(RC, ("H%03x", rp->rc_xid & 0xfff));
179 if ((rp->rc_flag & RC_LOCKED) != 0) {
180 rp->rc_flag |= RC_WANTED;
181 (void) tsleep((caddr_t)rp, 0, "nfsrc", 0);
184 rp->rc_flag |= RC_LOCKED;
185 /* If not at end of LRU chain, move it there */
186 if (TAILQ_NEXT(rp, rc_lru) != NULL) {
187 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
188 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
190 if (rp->rc_state == RC_UNUSED)
191 panic("nfsrv cache");
192 if (rp->rc_state == RC_INPROG) {
193 nfsstats.srvcache_inproghits++;
195 } else if (rp->rc_flag & RC_REPSTATUS) {
196 nfsstats.srvcache_nonidemdonehits++;
197 nfs_rephead(0, nd, slp, rp->rc_status,
200 } else if (rp->rc_flag & RC_REPMBUF) {
201 nfsstats.srvcache_nonidemdonehits++;
202 *repp = m_copym(rp->rc_reply, 0, M_COPYALL,
206 nfsstats.srvcache_idemdonehits++;
207 rp->rc_state = RC_INPROG;
210 rp->rc_flag &= ~RC_LOCKED;
211 if (rp->rc_flag & RC_WANTED) {
212 rp->rc_flag &= ~RC_WANTED;
218 nfsstats.srvcache_misses++;
219 NFS_DPF(RC, ("M%03x", nd->nd_retxid & 0xfff));
220 if (numnfsrvcache < desirednfsrvcache) {
221 rp = (struct nfsrvcache *)kmalloc((u_long)sizeof *rp,
222 M_NFSD, M_WAITOK | M_ZERO);
224 rp->rc_flag = RC_LOCKED;
226 rp = TAILQ_FIRST(&nfsrvlruhead);
227 while ((rp->rc_flag & RC_LOCKED) != 0) {
228 rp->rc_flag |= RC_WANTED;
229 (void) tsleep((caddr_t)rp, 0, "nfsrc", 0);
230 rp = TAILQ_FIRST(&nfsrvlruhead);
232 rp->rc_flag |= RC_LOCKED;
233 LIST_REMOVE(rp, rc_hash);
234 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
235 if (rp->rc_flag & RC_REPMBUF)
236 m_freem(rp->rc_reply);
237 if (rp->rc_flag & RC_NAM)
238 FREE(rp->rc_nam, M_SONAME);
239 rp->rc_flag &= (RC_LOCKED | RC_WANTED);
241 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
242 rp->rc_state = RC_INPROG;
243 rp->rc_xid = nd->nd_retxid;
244 saddr = (struct sockaddr_in *)nd->nd_nam;
245 switch (saddr->sin_family) {
247 rp->rc_flag |= RC_INETADDR;
248 rp->rc_inetaddr = saddr->sin_addr.s_addr;
252 rp->rc_flag |= RC_NAM;
253 rp->rc_nam = dup_sockaddr(nd->nd_nam);
256 rp->rc_proc = nd->nd_procnum;
257 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
258 rp->rc_flag &= ~RC_LOCKED;
259 if (rp->rc_flag & RC_WANTED) {
260 rp->rc_flag &= ~RC_WANTED;
267 * Update a request cache entry after the rpc has been done
270 nfsrv_updatecache(struct nfsrv_descript *nd, int repvalid, struct mbuf *repmbuf)
272 struct nfsrvcache *rp;
277 for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != 0;
278 rp = rp->rc_hash.le_next) {
279 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
280 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
281 NFS_DPF(RC, ("U%03x", rp->rc_xid & 0xfff));
282 if ((rp->rc_flag & RC_LOCKED) != 0) {
283 rp->rc_flag |= RC_WANTED;
284 (void) tsleep((caddr_t)rp, 0, "nfsrc", 0);
287 rp->rc_flag |= RC_LOCKED;
288 if (rp->rc_state == RC_DONE) {
290 * This can occur if the cache is too small.
291 * Retransmits of the same request aren't
292 * dropped so we may see the operation
293 * complete more then once.
295 if (rp->rc_flag & RC_REPMBUF) {
296 m_freem(rp->rc_reply);
297 rp->rc_flag &= ~RC_REPMBUF;
300 rp->rc_state = RC_DONE;
302 * If we have a valid reply update status and save
303 * the reply for non-idempotent rpc's.
305 if (repvalid && nonidempotent[nd->nd_procnum]) {
306 if ((nd->nd_flag & ND_NFSV3) == 0 &&
307 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) {
308 rp->rc_status = nd->nd_repstat;
309 rp->rc_flag |= RC_REPSTATUS;
311 rp->rc_reply = m_copym(repmbuf,
312 0, M_COPYALL, MB_WAIT);
313 rp->rc_flag |= RC_REPMBUF;
316 rp->rc_flag &= ~RC_LOCKED;
317 if (rp->rc_flag & RC_WANTED) {
318 rp->rc_flag &= ~RC_WANTED;
324 NFS_DPF(RC, ("L%03x", nd->nd_retxid & 0xfff));
328 * Clean out the cache. Called when the last nfsd terminates.
331 nfsrv_cleancache(void)
333 struct nfsrvcache *rp, *nextrp;
335 TAILQ_FOREACH_MUTABLE(rp, &nfsrvlruhead, rc_lru, nextrp) {
336 LIST_REMOVE(rp, rc_hash);
337 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
338 if (rp->rc_flag & RC_REPMBUF)
339 m_freem(rp->rc_reply);
340 if (rp->rc_flag & RC_NAM)
341 kfree(rp->rc_nam, M_SONAME);
347 #endif /* NFS_NOSERVER */