1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that the above copyright notice and this paragraph are 10 * duplicated in all such forms and that any documentation, 11 * advertising materials, and other materials related to such 12 * distribution and use acknowledge that the software was developed 13 * by the University of California, Berkeley. The name of the 14 * University may not be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19 * 20 * @(#)nfs_srvcache.c 7.1 (Berkeley) 12/20/89 21 */ 22 23 #include "param.h" 24 #include "user.h" 25 #include "vnode.h" 26 #include "mount.h" 27 #include "kernel.h" 28 #include "mbuf.h" 29 #include "socket.h" 30 #include "socketvar.h" 31 #include "netinet/in.h" 32 #include "nfsm_subs.h" 33 #include "nfsv2.h" 34 #include "nfsrvcache.h" 35 #include "nfs.h" 36 37 #if ((NFSRCHSZ&(NFSRCHSZ-1)) == 0) 38 #define NFSRCHASH(xid) (((xid)+((xid)>>16))&(NFSRCHSZ-1)) 39 #else 40 #define NFSRCHASH(xid) (((unsigned)((xid)+((xid)>>16)))%NFSRCHSZ) 41 #endif 42 43 union rhead { 44 union rhead *rh_head[2]; 45 struct nfsrvcache *rh_chain[2]; 46 } rhead[NFSRCHSZ]; 47 48 static struct nfsrvcache nfsrvcachehead; 49 static struct nfsrvcache nfsrvcache[NFSRVCACHESIZ]; 50 51 #define TRUE 1 52 #define FALSE 0 53 54 /* 55 * Static array that defines which nfs rpc's are nonidempotent 56 */ 57 static int nonidempotent[NFS_NPROCS] = { 58 FALSE, 59 FALSE, 60 TRUE, 61 FALSE, 62 FALSE, 63 FALSE, 64 FALSE, 65 FALSE, 66 TRUE, 67 TRUE, 68 TRUE, 69 TRUE, 70 TRUE, 71 TRUE, 72 TRUE, 73 TRUE, 74 FALSE, 75 FALSE, 76 }; 77 78 /* True iff the rpc reply is an nfs status ONLY! */ 79 static int repliesstatus[NFS_NPROCS] = { 80 FALSE, 81 FALSE, 82 FALSE, 83 FALSE, 84 FALSE, 85 FALSE, 86 FALSE, 87 FALSE, 88 FALSE, 89 FALSE, 90 TRUE, 91 TRUE, 92 TRUE, 93 TRUE, 94 FALSE, 95 TRUE, 96 FALSE, 97 FALSE, 98 }; 99 100 /* 101 * Initialize the server request cache list 102 */ 103 nfsrv_initcache() 104 { 105 register int i; 106 register struct nfsrvcache *rp = nfsrvcache; 107 register struct nfsrvcache *hp = &nfsrvcachehead; 108 register union rhead *rh = rhead; 109 110 for (i = NFSRCHSZ; --i >= 0; rh++) { 111 rh->rh_head[0] = rh; 112 rh->rh_head[1] = rh; 113 } 114 hp->rc_next = hp->rc_prev = hp; 115 for (i = NFSRVCACHESIZ; i-- > 0; ) { 116 rp->rc_state = RC_UNUSED; 117 rp->rc_flag = 0; 118 rp->rc_forw = rp; 119 rp->rc_back = rp; 120 rp->rc_next = hp->rc_next; 121 hp->rc_next->rc_prev = rp; 122 rp->rc_prev = hp; 123 hp->rc_next = rp; 124 rp++; 125 } 126 } 127 128 /* 129 * Look for the request in the cache 130 * If found then 131 * return action and optionally reply 132 * else 133 * insert it in the cache 134 * 135 * The rules are as follows: 136 * - if in progress, return DROP request 137 * - if completed within DELAY of the current time, return DROP it 138 * - if completed a longer time ago return REPLY if the reply was cached or 139 * return DOIT 140 * Update/add new request at end of lru list 141 */ 142 nfsrv_getcache(nam, xid, proc, repp) 143 struct mbuf *nam; 144 u_long xid; 145 int proc; 146 struct mbuf **repp; 147 { 148 register struct nfsrvcache *rp; 149 register union rhead *rh; 150 register u_long saddr; 151 struct mbuf *mb; 152 caddr_t bpos; 153 int ret; 154 155 rh = &rhead[NFSRCHASH(xid)]; 156 saddr = mtod(nam, struct sockaddr_in *)->sin_addr.s_addr; 157 loop: 158 for (rp = rh->rh_chain[0]; rp != (struct nfsrvcache *)rh; rp = rp->rc_forw) { 159 if (xid == rp->rc_xid && saddr == rp->rc_saddr && 160 proc == rp->rc_proc) { 161 if ((rp->rc_flag & RC_LOCKED) != 0) { 162 rp->rc_flag |= RC_WANTED; 163 sleep((caddr_t)rp, PZERO-1); 164 goto loop; 165 } 166 rp->rc_flag |= RC_LOCKED; 167 put_at_head(rp); 168 if (rp->rc_state == RC_UNUSED) 169 panic("nfsrv cache"); 170 if (rp->rc_state == RC_INPROG || 171 (time.tv_sec - rp->rc_timestamp) < RC_DELAY) { 172 nfsstats.srvcache_inproghits++; 173 ret = RC_DROPIT; 174 } else if (rp->rc_flag & RC_REPSTATUS) { 175 nfsstats.srvcache_idemdonehits++; 176 nfs_rephead(0, xid, rp->rc_status, repp, &mb, 177 &bpos); 178 rp->rc_timestamp = time.tv_sec; 179 ret = RC_REPLY; 180 } else if (rp->rc_flag & RC_REPMBUF) { 181 nfsstats.srvcache_idemdonehits++; 182 *repp = NFSMCOPY(rp->rc_reply, 0, M_COPYALL, 183 M_WAIT); 184 rp->rc_timestamp = time.tv_sec; 185 ret = RC_REPLY; 186 } else { 187 nfsstats.srvcache_nonidemdonehits++; 188 rp->rc_state = RC_INPROG; 189 ret = RC_DOIT; 190 } 191 rp->rc_flag &= ~RC_LOCKED; 192 if (rp->rc_flag & RC_WANTED) { 193 rp->rc_flag &= ~RC_WANTED; 194 wakeup((caddr_t)rp); 195 } 196 return (ret); 197 } 198 } 199 nfsstats.srvcache_misses++; 200 rp = nfsrvcachehead.rc_prev; 201 while ((rp->rc_flag & RC_LOCKED) != 0) { 202 rp->rc_flag |= RC_WANTED; 203 sleep((caddr_t)rp, PZERO-1); 204 } 205 remque(rp); 206 put_at_head(rp); 207 if (rp->rc_flag & RC_REPMBUF) 208 mb = rp->rc_reply; 209 else 210 mb = (struct mbuf *)0; 211 rp->rc_flag = 0; 212 rp->rc_state = RC_INPROG; 213 rp->rc_xid = xid; 214 rp->rc_saddr = saddr; 215 rp->rc_proc = proc; 216 insque(rp, rh); 217 if (mb) 218 m_freem(mb); 219 return (RC_DOIT); 220 } 221 222 /* 223 * Update a request cache entry after the rpc has been done 224 */ 225 nfsrv_updatecache(nam, xid, proc, repstat, repmbuf) 226 struct mbuf *nam; 227 u_long xid; 228 int proc; 229 int repstat; 230 struct mbuf *repmbuf; 231 { 232 register struct nfsrvcache *rp; 233 register union rhead *rh; 234 register u_long saddr; 235 236 rh = &rhead[NFSRCHASH(xid)]; 237 saddr = mtod(nam, struct sockaddr_in *)->sin_addr.s_addr; 238 loop: 239 for (rp = rh->rh_chain[0]; rp != (struct nfsrvcache *)rh; rp = rp->rc_forw) { 240 if (xid == rp->rc_xid && saddr == rp->rc_saddr && 241 proc == rp->rc_proc) { 242 if ((rp->rc_flag & RC_LOCKED) != 0) { 243 rp->rc_flag |= RC_WANTED; 244 sleep((caddr_t)rp, PZERO-1); 245 goto loop; 246 } 247 rp->rc_flag |= RC_LOCKED; 248 rp->rc_state = RC_DONE; 249 rp->rc_timestamp = time.tv_sec; 250 if (nonidempotent[proc]) { 251 if (repliesstatus[proc]) { 252 rp->rc_status = repstat; 253 rp->rc_flag |= RC_REPSTATUS; 254 } else { 255 rp->rc_reply = NFSMCOPY(repmbuf, 0, 256 M_COPYALL, M_WAIT); 257 rp->rc_flag |= RC_REPMBUF; 258 } 259 } 260 rp->rc_flag &= ~RC_LOCKED; 261 if (rp->rc_flag & RC_WANTED) { 262 rp->rc_flag &= ~RC_WANTED; 263 wakeup((caddr_t)rp); 264 } 265 return; 266 } 267 } 268 } 269