umap_vfsops.c revision 1.87
1 /* $NetBSD: umap_vfsops.c,v 1.87 2012/03/13 18:40:58 elad Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * the UCLA Ficus project. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)null_vfsops.c 1.5 (Berkeley) 7/10/92 35 * @(#)umap_vfsops.c 8.8 (Berkeley) 5/14/95 36 */ 37 38 /* 39 * Umap Layer 40 * (See mount_umap(8) for a description of this layer.) 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.87 2012/03/13 18:40:58 elad Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/sysctl.h> 49 #include <sys/proc.h> 50 #include <sys/time.h> 51 #include <sys/vnode.h> 52 #include <sys/mount.h> 53 #include <sys/namei.h> 54 #include <sys/malloc.h> 55 #include <sys/kauth.h> 56 #include <sys/module.h> 57 58 #include <miscfs/umapfs/umap.h> 59 #include <miscfs/genfs/layer_extern.h> 60 61 MODULE(MODULE_CLASS_VFS, umap, "layerfs"); 62 63 VFS_PROTOS(umapfs); 64 65 static struct sysctllog *umapfs_sysctl_log; 66 67 /* 68 * Mount umap layer 69 */ 70 int 71 umapfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 72 { 73 struct lwp *l = curlwp; 74 struct pathbuf *pb; 75 struct nameidata nd; 76 struct umap_args *args = data; 77 struct vnode *lowerrootvp, *vp; 78 struct umap_mount *amp; 79 int error; 80 #ifdef UMAPFS_DIAGNOSTIC 81 int i; 82 #endif 83 84 if (*data_len < sizeof *args) 85 return EINVAL; 86 87 if (mp->mnt_flag & MNT_GETARGS) { 88 amp = MOUNTTOUMAPMOUNT(mp); 89 if (amp == NULL) 90 return EIO; 91 args->la.target = NULL; 92 args->nentries = amp->info_nentries; 93 args->gnentries = amp->info_gnentries; 94 *data_len = sizeof *args; 95 return 0; 96 } 97 98 /* only for root */ 99 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, 100 KAUTH_REQ_SYSTEM_MOUNT_UMAP, NULL, NULL, NULL); 101 if (error) 102 return error; 103 104 #ifdef UMAPFS_DIAGNOSTIC 105 printf("umapfs_mount(mp = %p)\n", mp); 106 #endif 107 108 /* 109 * Update is not supported 110 */ 111 if (mp->mnt_flag & MNT_UPDATE) 112 return EOPNOTSUPP; 113 114 /* 115 * Find lower node 116 */ 117 error = pathbuf_copyin(args->umap_target, &pb); 118 if (error) { 119 return error; 120 } 121 NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); 122 if ((error = namei(&nd)) != 0) { 123 pathbuf_destroy(pb); 124 return error; 125 } 126 127 /* 128 * Sanity check on lower vnode 129 */ 130 lowerrootvp = nd.ni_vp; 131 pathbuf_destroy(pb); 132 #ifdef UMAPFS_DIAGNOSTIC 133 printf("vp = %p, check for VDIR...\n", lowerrootvp); 134 #endif 135 136 if (lowerrootvp->v_type != VDIR) { 137 vput(lowerrootvp); 138 return (EINVAL); 139 } 140 141 #ifdef UMAPFS_DIAGNOSTIC 142 printf("mp = %p\n", mp); 143 #endif 144 145 amp = (struct umap_mount *) malloc(sizeof(struct umap_mount), 146 M_UFSMNT, M_WAITOK); /* XXX */ 147 memset(amp, 0, sizeof(struct umap_mount)); 148 149 mp->mnt_data = amp; 150 amp->umapm_vfs = lowerrootvp->v_mount; 151 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 152 mp->mnt_flag |= MNT_LOCAL; 153 154 /* 155 * Now copy in the number of entries and maps for umap mapping. 156 */ 157 if (args->nentries > MAPFILEENTRIES || args->gnentries > GMAPFILEENTRIES) { 158 vput(lowerrootvp); 159 return (error); 160 } 161 162 amp->info_nentries = args->nentries; 163 amp->info_gnentries = args->gnentries; 164 error = copyin(args->mapdata, amp->info_mapdata, 165 2*sizeof(u_long)*args->nentries); 166 if (error) { 167 vput(lowerrootvp); 168 return (error); 169 } 170 171 #ifdef UMAPFS_DIAGNOSTIC 172 printf("umap_mount:nentries %d\n",args->nentries); 173 for (i = 0; i < args->nentries; i++) 174 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 175 amp->info_mapdata[i][1]); 176 #endif 177 178 error = copyin(args->gmapdata, amp->info_gmapdata, 179 2*sizeof(u_long)*args->gnentries); 180 if (error) { 181 vput(lowerrootvp); 182 return (error); 183 } 184 185 #ifdef UMAPFS_DIAGNOSTIC 186 printf("umap_mount:gnentries %d\n",args->gnentries); 187 for (i = 0; i < args->gnentries; i++) 188 printf("\tgroup %ld maps to %ld\n", 189 amp->info_gmapdata[i][0], 190 amp->info_gmapdata[i][1]); 191 #endif 192 193 /* 194 * Make sure the mount point's sufficiently initialized 195 * that the node create call will work. 196 */ 197 vfs_getnewfsid(mp); 198 amp->umapm_size = sizeof(struct umap_node); 199 amp->umapm_tag = VT_UMAP; 200 amp->umapm_bypass = umap_bypass; 201 amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */ 202 amp->umapm_vnodeop_p = umap_vnodeop_p; 203 mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE); 204 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true, 205 &->umapm_node_hash); 206 207 208 /* 209 * fix up umap node for root vnode. 210 */ 211 error = layer_node_create(mp, lowerrootvp, &vp); 212 /* 213 * Make sure the node alias worked 214 */ 215 if (error) { 216 vput(lowerrootvp); 217 hashdone(amp->umapm_node_hashtbl, HASH_LIST, 218 amp->umapm_node_hash); 219 free(amp, M_UFSMNT); /* XXX */ 220 return (error); 221 } 222 /* 223 * Unlock the node (either the lower or the alias) 224 */ 225 vp->v_vflag |= VV_ROOT; 226 VOP_UNLOCK(vp); 227 228 /* 229 * Keep a held reference to the root vnode. 230 * It is vrele'd in umapfs_unmount. 231 */ 232 amp->umapm_rootvp = vp; 233 234 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 235 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 236 #ifdef UMAPFS_DIAGNOSTIC 237 printf("umapfs_mount: lower %s, alias at %s\n", 238 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 239 #endif 240 return error; 241 } 242 243 /* 244 * Free reference to umap layer 245 */ 246 int 247 umapfs_unmount(struct mount *mp, int mntflags) 248 { 249 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 250 struct vnode *rtvp = amp->umapm_rootvp; 251 int error; 252 int flags = 0; 253 254 #ifdef UMAPFS_DIAGNOSTIC 255 printf("umapfs_unmount(mp = %p)\n", mp); 256 #endif 257 258 if (mntflags & MNT_FORCE) 259 flags |= FORCECLOSE; 260 261 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 262 return (EBUSY); 263 if ((error = vflush(mp, rtvp, flags)) != 0) 264 return (error); 265 266 #ifdef UMAPFS_DIAGNOSTIC 267 vprint("alias root of lower", rtvp); 268 #endif 269 /* 270 * Blow it away for future re-use 271 */ 272 vgone(rtvp); 273 /* 274 * Finally, throw away the umap_mount structure 275 */ 276 mutex_destroy(&->umapm_hashlock); 277 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash); 278 free(amp, M_UFSMNT); /* XXX */ 279 mp->mnt_data = NULL; 280 return (0); 281 } 282 283 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 284 285 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 286 &umapfs_vnodeop_opv_desc, 287 NULL, 288 }; 289 290 struct vfsops umapfs_vfsops = { 291 MOUNT_UMAP, 292 sizeof (struct umap_args), 293 umapfs_mount, 294 layerfs_start, 295 umapfs_unmount, 296 layerfs_root, 297 layerfs_quotactl, 298 layerfs_statvfs, 299 layerfs_sync, 300 layerfs_vget, 301 layerfs_fhtovp, 302 layerfs_vptofh, 303 layerfs_init, 304 NULL, 305 layerfs_done, 306 NULL, /* vfs_mountroot */ 307 layerfs_snapshot, 308 vfs_stdextattrctl, 309 (void *)eopnotsupp, /* vfs_suspendctl */ 310 layerfs_renamelock_enter, 311 layerfs_renamelock_exit, 312 (void *)eopnotsupp, 313 umapfs_vnodeopv_descs, 314 0, /* vfs_refcount */ 315 { NULL, NULL }, 316 }; 317 318 static int 319 umap_modcmd(modcmd_t cmd, void *arg) 320 { 321 int error; 322 323 switch (cmd) { 324 case MODULE_CMD_INIT: 325 error = vfs_attach(&umapfs_vfsops); 326 if (error != 0) 327 break; 328 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 329 CTLFLAG_PERMANENT, 330 CTLTYPE_NODE, "vfs", NULL, 331 NULL, 0, NULL, 0, 332 CTL_VFS, CTL_EOL); 333 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 334 CTLFLAG_PERMANENT, 335 CTLTYPE_NODE, "umap", 336 SYSCTL_DESCR("UID/GID remapping file system"), 337 NULL, 0, NULL, 0, 338 CTL_VFS, 10, CTL_EOL); 339 /* 340 * XXX the "10" above could be dynamic, thereby eliminating 341 * one more instance of the "number to vfs" mapping problem, 342 * but "10" is the order as taken from sys/mount.h 343 */ 344 break; 345 case MODULE_CMD_FINI: 346 error = vfs_detach(&umapfs_vfsops); 347 if (error != 0) 348 break; 349 sysctl_teardown(&umapfs_sysctl_log); 350 break; 351 default: 352 error = ENOTTY; 353 break; 354 } 355 356 return (error); 357 } 358
Indexes created Tue Sep 23 02:09:52 GMT 2025