Annotation of sys/nfs/nfs_srvcache.c, Revision 1.1.1.1
1.1 nbrk 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: }
CVSweb