Annotation of sys/nfs/nfs_srvcache.c, Revision 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: }
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