1 /* $NetBSD: umap_vfsops.c,v 1.86 2010/11/19 06:44:46 dholland 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 1.86 2010/11/19 06:44:46 dholland 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 if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, 100 NULL)) != 0) 101 return error; 102 103 #ifdef UMAPFS_DIAGNOSTIC 104 printf("umapfs_mount(mp = %p)\n", mp); 105 #endif 106 107 /* 108 * Update is not supported 109 */ 110 if (mp->mnt_flag & MNT_UPDATE) 111 return EOPNOTSUPP; 112 113 /* 114 * Find lower node 115 */ 116 error = pathbuf_copyin(args->umap_target, &pb); 117 if (error) { 118 return error; 119 } 120 NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); 121 if ((error = namei(&nd)) != 0) { 122 pathbuf_destroy(pb); 123 return error; 124 } 125 126 /* 127 * Sanity check on lower vnode 128 */ 129 lowerrootvp = nd.ni_vp; 130 pathbuf_destroy(pb); 131 #ifdef UMAPFS_DIAGNOSTIC 132 printf("vp = %p, check for VDIR...\n", lowerrootvp); 133 #endif 134 135 if (lowerrootvp->v_type != VDIR) { 136 vput(lowerrootvp); 137 return (EINVAL); 138 } 139 140 #ifdef UMAPFS_DIAGNOSTIC 141 printf("mp = %p\n", mp); 142 #endif 143 144 amp = (struct umap_mount *) malloc(sizeof(struct umap_mount), 145 M_UFSMNT, M_WAITOK); /* XXX */ 146 memset(amp, 0, sizeof(struct umap_mount)); 147 148 mp->mnt_data = amp; 149 amp->umapm_vfs = lowerrootvp->v_mount; 150 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 151 mp->mnt_flag |= MNT_LOCAL; 152 153 /* 154 * Now copy in the number of entries and maps for umap mapping. 155 */ 156 if (args->nentries > MAPFILEENTRIES || args->gnentries > GMAPFILEENTRIES) { 157 vput(lowerrootvp); 158 return (error); 159 } 160 161 amp->info_nentries = args->nentries; 162 amp->info_gnentries = args->gnentries; 163 error = copyin(args->mapdata, amp->info_mapdata, 164 2*sizeof(u_long)*args->nentries); 165 if (error) { 166 vput(lowerrootvp); 167 return (error); 168 } 169 170 #ifdef UMAPFS_DIAGNOSTIC 171 printf("umap_mount:nentries %d\n",args->nentries); 172 for (i = 0; i < args->nentries; i++) 173 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 174 amp->info_mapdata[i][1]); 175 #endif 176 177 error = copyin(args->gmapdata, amp->info_gmapdata, 178 2*sizeof(u_long)*args->gnentries); 179 if (error) { 180 vput(lowerrootvp); 181 return (error); 182 } 183 184 #ifdef UMAPFS_DIAGNOSTIC 185 printf("umap_mount:gnentries %d\n",args->gnentries); 186 for (i = 0; i < args->gnentries; i++) 187 printf("\tgroup %ld maps to %ld\n", 188 amp->info_gmapdata[i][0], 189 amp->info_gmapdata[i][1]); 190 #endif 191 192 /* 193 * Make sure the mount point's sufficiently initialized 194 * that the node create call will work. 195 */ 196 vfs_getnewfsid(mp); 197 amp->umapm_size = sizeof(struct umap_node); 198 amp->umapm_tag = VT_UMAP; 199 amp->umapm_bypass = umap_bypass; 200 amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */ 201 amp->umapm_vnodeop_p = umap_vnodeop_p; 202 mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE); 203 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true, 204 &->umapm_node_hash); 205 206 207 /* 208 * fix up umap node for root vnode. 209 */ 210 error = layer_node_create(mp, lowerrootvp, &vp); 211 /* 212 * Make sure the node alias worked 213 */ 214 if (error) { 215 vput(lowerrootvp); 216 hashdone(amp->umapm_node_hashtbl, HASH_LIST, 217 amp->umapm_node_hash); 218 free(amp, M_UFSMNT); /* XXX */ 219 return (error); 220 } 221 /* 222 * Unlock the node (either the lower or the alias) 223 */ 224 vp->v_vflag |= VV_ROOT; 225 VOP_UNLOCK(vp); 226 227 /* 228 * Keep a held reference to the root vnode. 229 * It is vrele'd in umapfs_unmount. 230 */ 231 amp->umapm_rootvp = vp; 232 233 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 234 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 235 #ifdef UMAPFS_DIAGNOSTIC 236 printf("umapfs_mount: lower %s, alias at %s\n", 237 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 238 #endif 239 return error; 240 } 241 242 /* 243 * Free reference to umap layer 244 */ 245 int 246 umapfs_unmount(struct mount *mp, int mntflags) 247 { 248 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 249 struct vnode *rtvp = amp->umapm_rootvp; 250 int error; 251 int flags = 0; 252 253 #ifdef UMAPFS_DIAGNOSTIC 254 printf("umapfs_unmount(mp = %p)\n", mp); 255 #endif 256 257 if (mntflags & MNT_FORCE) 258 flags |= FORCECLOSE; 259 260 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 261 return (EBUSY); 262 if ((error = vflush(mp, rtvp, flags)) != 0) 263 return (error); 264 265 #ifdef UMAPFS_DIAGNOSTIC 266 vprint("alias root of lower", rtvp); 267 #endif 268 /* 269 * Blow it away for future re-use 270 */ 271 vgone(rtvp); 272 /* 273 * Finally, throw away the umap_mount structure 274 */ 275 mutex_destroy(&->umapm_hashlock); 276 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash); 277 free(amp, M_UFSMNT); /* XXX */ 278 mp->mnt_data = NULL; 279 return (0); 280 } 281 282 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 283 284 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 285 &umapfs_vnodeop_opv_desc, 286 NULL, 287 }; 288 289 struct vfsops umapfs_vfsops = { 290 MOUNT_UMAP, 291 sizeof (struct umap_args), 292 umapfs_mount, 293 layerfs_start, 294 umapfs_unmount, 295 layerfs_root, 296 layerfs_quotactl, 297 layerfs_statvfs, 298 layerfs_sync, 299 layerfs_vget, 300 layerfs_fhtovp, 301 layerfs_vptofh, 302 layerfs_init, 303 NULL, 304 layerfs_done, 305 NULL, /* vfs_mountroot */ 306 layerfs_snapshot, 307 vfs_stdextattrctl, 308 (void *)eopnotsupp, /* vfs_suspendctl */ 309 layerfs_renamelock_enter, 310 layerfs_renamelock_exit, 311 (void *)eopnotsupp, 312 umapfs_vnodeopv_descs, 313 0, /* vfs_refcount */ 314 { NULL, NULL }, 315 }; 316 317 static int 318 umap_modcmd(modcmd_t cmd, void *arg) 319 { 320 int error; 321 322 switch (cmd) { 323 case MODULE_CMD_INIT: 324 error = vfs_attach(&umapfs_vfsops); 325 if (error != 0) 326 break; 327 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 328 CTLFLAG_PERMANENT, 329 CTLTYPE_NODE, "vfs", NULL, 330 NULL, 0, NULL, 0, 331 CTL_VFS, CTL_EOL); 332 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 333 CTLFLAG_PERMANENT, 334 CTLTYPE_NODE, "umap", 335 SYSCTL_DESCR("UID/GID remapping file system"), 336 NULL, 0, NULL, 0, 337 CTL_VFS, 10, CTL_EOL); 338 /* 339 * XXX the "10" above could be dynamic, thereby eliminating 340 * one more instance of the "number to vfs" mapping problem, 341 * but "10" is the order as taken from sys/mount.h 342 */ 343 break; 344 case MODULE_CMD_FINI: 345 error = vfs_detach(&umapfs_vfsops); 346 if (error != 0) 347 break; 348 sysctl_teardown(&umapfs_sysctl_log); 349 break; 350 default: 351 error = ENOTTY; 352 break; 353 } 354 355 return (error); 356 } 357