1 /* $OpenBSD: nfs_srvcache.c,v 1.12 2004/12/26 21:22:14 miod Exp $ */
2 /* $NetBSD: nfs_srvcache.c,v 1.12 1996/02/18 11:53:49 fvdl Exp $ */
3
4 /*
5 * Copyright (c) 1989, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Rick Macklem at The University of Guelph.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95
36 */
37
38 /*
39 * Reference: Chet Juszczak, "Improving the Performance and Correctness
40 * of an NFS Server", in Proc. Winter 1989 USENIX Conference,
41 * pages 53-63. San Diego, February 1989.
42 */
43 #include <sys/param.h>
44 #include <sys/vnode.h>
45 #include <sys/mount.h>
46 #include <sys/kernel.h>
47 #include <sys/systm.h>
48 #include <sys/proc.h>
49 #include <sys/mbuf.h>
50 #include <sys/malloc.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53
54 #include <netinet/in.h>
55 #include <nfs/nfsm_subs.h>
56 #include <nfs/rpcv2.h>
57 #include <nfs/nfsproto.h>
58 #include <nfs/nfs.h>
59 #include <nfs/nfsrvcache.h>
60 #include <nfs/nfs_var.h>
61
62 extern struct nfsstats nfsstats;
63 extern int nfsv2_procid[NFS_NPROCS];
64 long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ;
65
66 #define NFSRCHASH(xid) \
67 (&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash])
68 LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl;
69 TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead;
70 u_long nfsrvhash;
71
72 #define TRUE 1
73 #define FALSE 0
74
75 #define NETFAMILY(rp) \
76 (((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_UNSPEC)
77
78 /*
79 * Static array that defines which nfs rpc's are nonidempotent
80 */
81 int nonidempotent[NFS_NPROCS] = {
82 FALSE,
83 FALSE,
84 TRUE,
85 FALSE,
86 FALSE,
87 FALSE,
88 FALSE,
89 TRUE,
90 TRUE,
91 TRUE,
92 TRUE,
93 TRUE,
94 TRUE,
95 TRUE,
96 TRUE,
97 TRUE,
98 FALSE,
99 FALSE,
100 FALSE,
101 FALSE,
102 FALSE,
103 FALSE,
104 FALSE,
105 FALSE,
106 FALSE,
107 FALSE,
108 };
109
110 /* True iff the rpc reply is an nfs status ONLY! */
111 static int nfsv2_repstat[NFS_NPROCS] = {
112 FALSE,
113 FALSE,
114 FALSE,
115 FALSE,
116 FALSE,
117 FALSE,
118 FALSE,
119 FALSE,
120 FALSE,
121 FALSE,
122 TRUE,
123 TRUE,
124 TRUE,
125 TRUE,
126 FALSE,
127 TRUE,
128 FALSE,
129 FALSE,
130 };
131
132 /*
133 * Initialize the server request cache list
134 */
135 void
136 nfsrv_initcache()
137 {
138
139 nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, M_WAITOK, &nfsrvhash);
140 TAILQ_INIT(&nfsrvlruhead);
141 }
142
143 /*
144 * Look for the request in the cache
145 * If found then
146 * return action and optionally reply
147 * else
148 * insert it in the cache
149 *
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
154 * return DOIT
155 * Update/add new request at end of lru list
156 */
157 int
158 nfsrv_getcache(nd, slp, repp)
159 struct nfsrv_descript *nd;
160 struct nfssvc_sock *slp;
161 struct mbuf **repp;
162 {
163 struct nfsrvcache *rp;
164 struct mbuf *mb;
165 struct sockaddr_in *saddr;
166 caddr_t bpos;
167 int ret;
168
169 /*
170 * Don't cache recent requests for reliable transport protocols.
171 * (Maybe we should for the case of a reconnect, but..)
172 */
173 if (!nd->nd_nam2)
174 return (RC_DOIT);
175 loop:
176 LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
177 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
178 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
179 if ((rp->rc_flag & RC_LOCKED) != 0) {
180 rp->rc_flag |= RC_WANTED;
181 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
182 goto loop;
183 }
184 rp->rc_flag |= RC_LOCKED;
185 /* If not at end of LRU chain, move it there */
186 if (TAILQ_NEXT(rp, rc_lru)) {
187 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
188 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
189 }
190 if (rp->rc_state == RC_UNUSED)
191 panic("nfsrv cache");
192 if (rp->rc_state == RC_INPROG) {
193 nfsstats.srvcache_inproghits++;
194 ret = RC_DROPIT;
195 } else if (rp->rc_flag & RC_REPSTATUS) {
196 nfsstats.srvcache_nonidemdonehits++;
197 nfs_rephead(0, nd, slp, rp->rc_status,
198 (u_quad_t *)0, repp, &mb, &bpos);
199 ret = RC_REPLY;
200 } else if (rp->rc_flag & RC_REPMBUF) {
201 nfsstats.srvcache_nonidemdonehits++;
202 *repp = m_copym(rp->rc_reply, 0, M_COPYALL,
203 M_WAIT);
204 ret = RC_REPLY;
205 } else {
206 nfsstats.srvcache_idemdonehits++;
207 rp->rc_state = RC_INPROG;
208 ret = RC_DOIT;
209 }
210 rp->rc_flag &= ~RC_LOCKED;
211 if (rp->rc_flag & RC_WANTED) {
212 rp->rc_flag &= ~RC_WANTED;
213 wakeup((caddr_t)rp);
214 }
215 return (ret);
216 }
217 }
218 nfsstats.srvcache_misses++;
219 if (numnfsrvcache < desirednfsrvcache) {
220 rp = (struct nfsrvcache *)malloc((u_long)sizeof *rp,
221 M_NFSD, M_WAITOK);
222 bzero((char *)rp, sizeof *rp);
223 numnfsrvcache++;
224 rp->rc_flag = RC_LOCKED;
225 } else {
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, PZERO-1, "nfsrc", 0);
230 rp = TAILQ_FIRST(&nfsrvlruhead);
231 }
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 MFREE(rp->rc_nam, mb);
239 rp->rc_flag &= (RC_LOCKED | RC_WANTED);
240 }
241 TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
242 rp->rc_state = RC_INPROG;
243 rp->rc_xid = nd->nd_retxid;
244 saddr = mtod(nd->nd_nam, struct sockaddr_in *);
245 switch (saddr->sin_family) {
246 case AF_INET:
247 rp->rc_flag |= RC_INETADDR;
248 rp->rc_inetaddr = saddr->sin_addr.s_addr;
249 break;
250 default:
251 rp->rc_flag |= RC_NAM;
252 rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT);
253 break;
254 };
255 rp->rc_proc = nd->nd_procnum;
256 LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
257 rp->rc_flag &= ~RC_LOCKED;
258 if (rp->rc_flag & RC_WANTED) {
259 rp->rc_flag &= ~RC_WANTED;
260 wakeup((caddr_t)rp);
261 }
262 return (RC_DOIT);
263 }
264
265 /*
266 * Update a request cache entry after the rpc has been done
267 */
268 void
269 nfsrv_updatecache(nd, repvalid, repmbuf)
270 struct nfsrv_descript *nd;
271 int repvalid;
272 struct mbuf *repmbuf;
273 {
274 struct nfsrvcache *rp;
275
276 if (!nd->nd_nam2)
277 return;
278 loop:
279 LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
280 if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
281 netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
282 if ((rp->rc_flag & RC_LOCKED) != 0) {
283 rp->rc_flag |= RC_WANTED;
284 (void) tsleep((caddr_t)rp, PZERO-1, "nfsrc", 0);
285 goto loop;
286 }
287 rp->rc_flag |= RC_LOCKED;
288 rp->rc_state = RC_DONE;
289 /*
290 * If we have a valid reply update status and save
291 * the reply for non-idempotent rpc's.
292 */
293 if (repvalid && nonidempotent[nd->nd_procnum]) {
294 if ((nd->nd_flag & ND_NFSV3) == 0 &&
295 nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) {
296 rp->rc_status = nd->nd_repstat;
297 rp->rc_flag |= RC_REPSTATUS;
298 } else {
299 rp->rc_reply = m_copym(repmbuf,
300 0, M_COPYALL, M_WAIT);
301 rp->rc_flag |= RC_REPMBUF;
302 }
303 }
304 rp->rc_flag &= ~RC_LOCKED;
305 if (rp->rc_flag & RC_WANTED) {
306 rp->rc_flag &= ~RC_WANTED;
307 wakeup((caddr_t)rp);
308 }
309 return;
310 }
311 }
312 }
313
314 /*
315 * Clean out the cache. Called when the last nfsd terminates.
316 */
317 void
318 nfsrv_cleancache()
319 {
320 struct nfsrvcache *rp, *nextrp;
321
322 for (rp = TAILQ_FIRST(&nfsrvlruhead); rp != NULL; rp = nextrp) {
323 nextrp = TAILQ_NEXT(rp, rc_lru);
324 LIST_REMOVE(rp, rc_hash);
325 TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
326 free(rp, M_NFSD);
327 }
328 numnfsrvcache = 0;
329 }