umap_subr.c revision 1.1.1.2
1 /* 2 * Copyright (c) 1992, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software donated to Berkeley by 6 * Jan-Simon Pendry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 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. 23 * 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 34 * SUCH DAMAGE. 35 * 36 * @(#)umap_subr.c 8.9 (Berkeley) 5/14/95 37 * 38 * From: $Id: umap_subr.c,v 1.1.1.2 1998/03/01 02:13:15 fvdl Exp $ 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/proc.h> 44 #include <sys/time.h> 45 #include <sys/types.h> 46 #include <sys/vnode.h> 47 #include <sys/mount.h> 48 #include <sys/namei.h> 49 #include <sys/malloc.h> 50 #include <miscfs/umapfs/umap.h> 51 52 #define LOG2_SIZEVNODE 7 /* log2(sizeof struct vnode) */ 53 #define NUMAPNODECACHE 16 54 55 /* 56 * Null layer cache: 57 * Each cache entry holds a reference to the target vnode 58 * along with a pointer to the alias vnode. When an 59 * entry is added the target vnode is VREF'd. When the 60 * alias is removed the target vnode is vrele'd. 61 */ 62 63 #define UMAP_NHASH(vp) \ 64 (&umap_node_hashtbl[(((u_long)vp)>>LOG2_SIZEVNODE) & umap_node_hash]) 65 LIST_HEAD(umap_node_hashhead, umap_node) *umap_node_hashtbl; 66 u_long umap_node_hash; 67 68 /* 69 * Initialise cache headers 70 */ 71 umapfs_init(vfsp) 72 struct vfsconf *vfsp; 73 { 74 75 #ifdef UMAPFS_DIAGNOSTIC 76 printf("umapfs_init\n"); /* printed during system boot */ 77 #endif 78 umap_node_hashtbl = hashinit(NUMAPNODECACHE, M_CACHE, &umap_node_hash); 79 } 80 81 /* 82 * umap_findid is called by various routines in umap_vnodeops.c to 83 * find a user or group id in a map. 84 */ 85 static u_long 86 umap_findid(id, map, nentries) 87 u_long id; 88 u_long map[][2]; 89 int nentries; 90 { 91 int i; 92 93 /* Find uid entry in map */ 94 i = 0; 95 while ((i<nentries) && ((map[i][0]) != id)) 96 i++; 97 98 if (i < nentries) 99 return (map[i][1]); 100 else 101 return (-1); 102 103 } 104 105 /* 106 * umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to 107 * find a user or group id in a map, in reverse. 108 */ 109 u_long 110 umap_reverse_findid(id, map, nentries) 111 u_long id; 112 u_long map[][2]; 113 int nentries; 114 { 115 int i; 116 117 /* Find uid entry in map */ 118 i = 0; 119 while ((i<nentries) && ((map[i][1]) != id)) 120 i++; 121 122 if (i < nentries) 123 return (map[i][0]); 124 else 125 return (-1); 126 127 } 128 129 /* 130 * Return alias for target vnode if already exists, else 0. 131 */ 132 static struct vnode * 133 umap_node_find(mp, targetvp) 134 struct mount *mp; 135 struct vnode *targetvp; 136 { 137 struct proc *p = curproc; /* XXX */ 138 struct umap_node_hashhead *hd; 139 struct umap_node *a; 140 struct vnode *vp; 141 142 #ifdef UMAPFS_DIAGNOSTIC 143 printf("umap_node_find(mp = %x, target = %x)\n", mp, targetvp); 144 #endif 145 146 /* 147 * Find hash base, and then search the (two-way) linked 148 * list looking for a umap_node structure which is referencing 149 * the target vnode. If found, the increment the umap_node 150 * reference count (but NOT the target vnode's VREF counter). 151 */ 152 hd = UMAP_NHASH(targetvp); 153 loop: 154 for (a = hd->lh_first; a != 0; a = a->umap_hash.le_next) { 155 if (a->umap_lowervp == targetvp && 156 a->umap_vnode->v_mount == mp) { 157 vp = UMAPTOV(a); 158 /* 159 * We need vget for the VXLOCK 160 * stuff, but we don't want to lock 161 * the lower node. 162 */ 163 if (vget(vp, 0, p)) { 164 #ifdef UMAPFS_DIAGNOSTIC 165 printf ("umap_node_find: vget failed.\n"); 166 #endif 167 goto loop; 168 } 169 return (vp); 170 } 171 } 172 173 #ifdef UMAPFS_DIAGNOSTIC 174 printf("umap_node_find(%x, %x): NOT found\n", mp, targetvp); 175 #endif 176 177 return (0); 178 } 179 180 /* 181 * Make a new umap_node node. 182 * Vp is the alias vnode, lofsvp is the target vnode. 183 * Maintain a reference to (targetvp). 184 */ 185 static int 186 umap_node_alloc(mp, lowervp, vpp) 187 struct mount *mp; 188 struct vnode *lowervp; 189 struct vnode **vpp; 190 { 191 struct umap_node_hashhead *hd; 192 struct umap_node *xp; 193 struct vnode *othervp, *vp; 194 int error; 195 196 if (error = getnewvnode(VT_UMAP, mp, umap_vnodeop_p, vpp)) 197 return (error); 198 vp = *vpp; 199 200 MALLOC(xp, struct umap_node *, sizeof(struct umap_node), 201 M_TEMP, M_WAITOK); 202 vp->v_type = lowervp->v_type; 203 xp->umap_vnode = vp; 204 vp->v_data = xp; 205 xp->umap_lowervp = lowervp; 206 /* 207 * Before we insert our new node onto the hash chains, 208 * check to see if someone else has beaten us to it. 209 * (We could have slept in MALLOC.) 210 */ 211 if (othervp = umap_node_find(lowervp)) { 212 FREE(xp, M_TEMP); 213 vp->v_type = VBAD; /* node is discarded */ 214 vp->v_usecount = 0; /* XXX */ 215 *vpp = othervp; 216 return (0); 217 } 218 VREF(lowervp); /* Extra VREF will be vrele'd in umap_node_create */ 219 hd = UMAP_NHASH(lowervp); 220 LIST_INSERT_HEAD(hd, xp, umap_hash); 221 return (0); 222 } 223 224 225 /* 226 * Try to find an existing umap_node vnode refering 227 * to it, otherwise make a new umap_node vnode which 228 * contains a reference to the target vnode. 229 */ 230 int 231 umap_node_create(mp, targetvp, newvpp) 232 struct mount *mp; 233 struct vnode *targetvp; 234 struct vnode **newvpp; 235 { 236 struct vnode *aliasvp; 237 238 if (aliasvp = umap_node_find(mp, targetvp)) { 239 /* 240 * Take another reference to the alias vnode 241 */ 242 #ifdef UMAPFS_DIAGNOSTIC 243 vprint("umap_node_create: exists", ap->umap_vnode); 244 #endif 245 /* VREF(aliasvp); */ 246 } else { 247 int error; 248 249 /* 250 * Get new vnode. 251 */ 252 #ifdef UMAPFS_DIAGNOSTIC 253 printf("umap_node_create: create new alias vnode\n"); 254 #endif 255 /* 256 * Make new vnode reference the umap_node. 257 */ 258 if (error = umap_node_alloc(mp, targetvp, &aliasvp)) 259 return (error); 260 261 /* 262 * aliasvp is already VREF'd by getnewvnode() 263 */ 264 } 265 266 vrele(targetvp); 267 268 #ifdef UMAPFS_DIAGNOSTIC 269 vprint("umap_node_create: alias", aliasvp); 270 vprint("umap_node_create: target", targetvp); 271 #endif 272 273 *newvpp = aliasvp; 274 return (0); 275 } 276 277 #ifdef UMAPFS_DIAGNOSTIC 278 int umap_checkvp_barrier = 1; 279 struct vnode * 280 umap_checkvp(vp, fil, lno) 281 struct vnode *vp; 282 char *fil; 283 int lno; 284 { 285 struct umap_node *a = VTOUMAP(vp); 286 #if 0 287 /* 288 * Can't do this check because vop_reclaim runs 289 * with funny vop vector. 290 */ 291 if (vp->v_op != umap_vnodeop_p) { 292 printf ("umap_checkvp: on non-umap-node\n"); 293 while (umap_checkvp_barrier) /*WAIT*/ ; 294 panic("umap_checkvp"); 295 } 296 #endif 297 if (a->umap_lowervp == NULL) { 298 /* Should never happen */ 299 int i; u_long *p; 300 printf("vp = %x, ZERO ptr\n", vp); 301 for (p = (u_long *) a, i = 0; i < 8; i++) 302 printf(" %x", p[i]); 303 printf("\n"); 304 /* wait for debugger */ 305 while (umap_checkvp_barrier) /*WAIT*/ ; 306 panic("umap_checkvp"); 307 } 308 if (a->umap_lowervp->v_usecount < 1) { 309 int i; u_long *p; 310 printf("vp = %x, unref'ed lowervp\n", vp); 311 for (p = (u_long *) a, i = 0; i < 8; i++) 312 printf(" %x", p[i]); 313 printf("\n"); 314 /* wait for debugger */ 315 while (umap_checkvp_barrier) /*WAIT*/ ; 316 panic ("umap with unref'ed lowervp"); 317 } 318 #if 0 319 printf("umap %x/%d -> %x/%d [%s, %d]\n", 320 a->umap_vnode, a->umap_vnode->v_usecount, 321 a->umap_lowervp, a->umap_lowervp->v_usecount, 322 fil, lno); 323 #endif 324 return (a->umap_lowervp); 325 } 326 #endif 327 328 /* umap_mapids maps all of the ids in a credential, both user and group. */ 329 330 void 331 umap_mapids(v_mount, credp) 332 struct mount *v_mount; 333 struct ucred *credp; 334 { 335 int i, unentries, gnentries; 336 u_long *groupmap, *usermap; 337 uid_t uid; 338 gid_t gid; 339 340 unentries = MOUNTTOUMAPMOUNT(v_mount)->info_nentries; 341 usermap = &(MOUNTTOUMAPMOUNT(v_mount)->info_mapdata[0][0]); 342 gnentries = MOUNTTOUMAPMOUNT(v_mount)->info_gnentries; 343 groupmap = &(MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata[0][0]); 344 345 /* Find uid entry in map */ 346 347 uid = (uid_t) umap_findid(credp->cr_uid, usermap, unentries); 348 349 if (uid != -1) 350 credp->cr_uid = uid; 351 else 352 credp->cr_uid = (uid_t) NOBODY; 353 354 #ifdef notdef 355 /* cr_gid is the same as cr_groups[0] in 4BSD */ 356 357 /* Find gid entry in map */ 358 359 gid = (gid_t) umap_findid(credp->cr_gid, groupmap, gnentries); 360 361 if (gid != -1) 362 credp->cr_gid = gid; 363 else 364 credp->cr_gid = NULLGROUP; 365 #endif 366 367 /* Now we must map each of the set of groups in the cr_groups 368 structure. */ 369 370 i = 0; 371 while (credp->cr_groups[i] != 0) { 372 gid = (gid_t) umap_findid(credp->cr_groups[i], 373 groupmap, gnentries); 374 375 if (gid != -1) 376 credp->cr_groups[i++] = gid; 377 else 378 credp->cr_groups[i++] = NULLGROUP; 379 } 380 } 381
Indexes created Thu Oct 02 14:10:14 GMT 2025