umap_vfsops.c revision 1.86.18.1
1 /* $NetBSD: umap_vfsops.c,v 1.86.18.1 2014/04/21 10:15:37 bouyer 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 1.86.18.1 2014/04/21 10:15:37 bouyer 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 (args == NULL) 85 return EINVAL; 86 if (*data_len < sizeof *args) 87 return EINVAL; 88 89 if (mp->mnt_flag & MNT_GETARGS) { 90 amp = MOUNTTOUMAPMOUNT(mp); 91 if (amp == NULL) 92 return EIO; 93 args->la.target = NULL; 94 args->nentries = amp->info_nentries; 95 args->gnentries = amp->info_gnentries; 96 *data_len = sizeof *args; 97 return 0; 98 } 99 100 /* only for root */ 101 if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, 102 NULL)) != 0) 103 return error; 104 105 #ifdef UMAPFS_DIAGNOSTIC 106 printf("umapfs_mount(mp = %p)\n", mp); 107 #endif 108 109 /* 110 * Update is not supported 111 */ 112 if (mp->mnt_flag & MNT_UPDATE) 113 return EOPNOTSUPP; 114 115 /* 116 * Find lower node 117 */ 118 error = pathbuf_copyin(args->umap_target, &pb); 119 if (error) { 120 return error; 121 } 122 NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); 123 if ((error = namei(&nd)) != 0) { 124 pathbuf_destroy(pb); 125 return error; 126 } 127 128 /* 129 * Sanity check on lower vnode 130 */ 131 lowerrootvp = nd.ni_vp; 132 pathbuf_destroy(pb); 133 #ifdef UMAPFS_DIAGNOSTIC 134 printf("vp = %p, check for VDIR...\n", lowerrootvp); 135 #endif 136 137 if (lowerrootvp->v_type != VDIR) { 138 vput(lowerrootvp); 139 return (EINVAL); 140 } 141 142 #ifdef UMAPFS_DIAGNOSTIC 143 printf("mp = %p\n", mp); 144 #endif 145 146 amp = (struct umap_mount *) malloc(sizeof(struct umap_mount), 147 M_UFSMNT, M_WAITOK); /* XXX */ 148 memset(amp, 0, sizeof(struct umap_mount)); 149 150 mp->mnt_data = amp; 151 amp->umapm_vfs = lowerrootvp->v_mount; 152 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 153 mp->mnt_flag |= MNT_LOCAL; 154 155 /* 156 * Now copy in the number of entries and maps for umap mapping. 157 */ 158 if (args->nentries > MAPFILEENTRIES || args->gnentries > GMAPFILEENTRIES) { 159 vput(lowerrootvp); 160 return (error); 161 } 162 163 amp->info_nentries = args->nentries; 164 amp->info_gnentries = args->gnentries; 165 error = copyin(args->mapdata, amp->info_mapdata, 166 2*sizeof(u_long)*args->nentries); 167 if (error) { 168 vput(lowerrootvp); 169 return (error); 170 } 171 172 #ifdef UMAPFS_DIAGNOSTIC 173 printf("umap_mount:nentries %d\n",args->nentries); 174 for (i = 0; i < args->nentries; i++) 175 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 176 amp->info_mapdata[i][1]); 177 #endif 178 179 error = copyin(args->gmapdata, amp->info_gmapdata, 180 2*sizeof(u_long)*args->gnentries); 181 if (error) { 182 vput(lowerrootvp); 183 return (error); 184 } 185 186 #ifdef UMAPFS_DIAGNOSTIC 187 printf("umap_mount:gnentries %d\n",args->gnentries); 188 for (i = 0; i < args->gnentries; i++) 189 printf("\tgroup %ld maps to %ld\n", 190 amp->info_gmapdata[i][0], 191 amp->info_gmapdata[i][1]); 192 #endif 193 194 /* 195 * Make sure the mount point's sufficiently initialized 196 * that the node create call will work. 197 */ 198 vfs_getnewfsid(mp); 199 amp->umapm_size = sizeof(struct umap_node); 200 amp->umapm_tag = VT_UMAP; 201 amp->umapm_bypass = umap_bypass; 202 amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */ 203 amp->umapm_vnodeop_p = umap_vnodeop_p; 204 mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE); 205 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true, 206 &->umapm_node_hash); 207 208 209 /* 210 * fix up umap node for root vnode. 211 */ 212 error = layer_node_create(mp, lowerrootvp, &vp); 213 /* 214 * Make sure the node alias worked 215 */ 216 if (error) { 217 vput(lowerrootvp); 218 hashdone(amp->umapm_node_hashtbl, HASH_LIST, 219 amp->umapm_node_hash); 220 free(amp, M_UFSMNT); /* XXX */ 221 return (error); 222 } 223 /* 224 * Unlock the node (either the lower or the alias) 225 */ 226 vp->v_vflag |= VV_ROOT; 227 VOP_UNLOCK(vp); 228 229 /* 230 * Keep a held reference to the root vnode. 231 * It is vrele'd in umapfs_unmount. 232 */ 233 amp->umapm_rootvp = vp; 234 235 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 236 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 237 #ifdef UMAPFS_DIAGNOSTIC 238 printf("umapfs_mount: lower %s, alias at %s\n", 239 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 240 #endif 241 return error; 242 } 243 244 /* 245 * Free reference to umap layer 246 */ 247 int 248 umapfs_unmount(struct mount *mp, int mntflags) 249 { 250 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 251 struct vnode *rtvp = amp->umapm_rootvp; 252 int error; 253 int flags = 0; 254 255 #ifdef UMAPFS_DIAGNOSTIC 256 printf("umapfs_unmount(mp = %p)\n", mp); 257 #endif 258 259 if (mntflags & MNT_FORCE) 260 flags |= FORCECLOSE; 261 262 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 263 return (EBUSY); 264 if ((error = vflush(mp, rtvp, flags)) != 0) 265 return (error); 266 267 #ifdef UMAPFS_DIAGNOSTIC 268 vprint("alias root of lower", rtvp); 269 #endif 270 /* 271 * Blow it away for future re-use 272 */ 273 vgone(rtvp); 274 /* 275 * Finally, throw away the umap_mount structure 276 */ 277 mutex_destroy(&->umapm_hashlock); 278 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash); 279 free(amp, M_UFSMNT); /* XXX */ 280 mp->mnt_data = NULL; 281 return (0); 282 } 283 284 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 285 286 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 287 &umapfs_vnodeop_opv_desc, 288 NULL, 289 }; 290 291 struct vfsops umapfs_vfsops = { 292 MOUNT_UMAP, 293 sizeof (struct umap_args), 294 umapfs_mount, 295 layerfs_start, 296 umapfs_unmount, 297 layerfs_root, 298 layerfs_quotactl, 299 layerfs_statvfs, 300 layerfs_sync, 301 layerfs_vget, 302 layerfs_fhtovp, 303 layerfs_vptofh, 304 layerfs_init, 305 NULL, 306 layerfs_done, 307 NULL, /* vfs_mountroot */ 308 layerfs_snapshot, 309 vfs_stdextattrctl, 310 (void *)eopnotsupp, /* vfs_suspendctl */ 311 layerfs_renamelock_enter, 312 layerfs_renamelock_exit, 313 (void *)eopnotsupp, 314 umapfs_vnodeopv_descs, 315 0, /* vfs_refcount */ 316 { NULL, NULL }, 317 }; 318 319 static int 320 umap_modcmd(modcmd_t cmd, void *arg) 321 { 322 int error; 323 324 switch (cmd) { 325 case MODULE_CMD_INIT: 326 error = vfs_attach(&umapfs_vfsops); 327 if (error != 0) 328 break; 329 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 330 CTLFLAG_PERMANENT, 331 CTLTYPE_NODE, "vfs", NULL, 332 NULL, 0, NULL, 0, 333 CTL_VFS, CTL_EOL); 334 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 335 CTLFLAG_PERMANENT, 336 CTLTYPE_NODE, "umap", 337 SYSCTL_DESCR("UID/GID remapping file system"), 338 NULL, 0, NULL, 0, 339 CTL_VFS, 10, CTL_EOL); 340 /* 341 * XXX the "10" above could be dynamic, thereby eliminating 342 * one more instance of the "number to vfs" mapping problem, 343 * but "10" is the order as taken from sys/mount.h 344 */ 345 break; 346 case MODULE_CMD_FINI: 347 error = vfs_detach(&umapfs_vfsops); 348 if (error != 0) 349 break; 350 sysctl_teardown(&umapfs_sysctl_log); 351 break; 352 default: 353 error = ENOTTY; 354 break; 355 } 356 357 return (error); 358 } 359
Indexes created Tue Oct 07 21:09:53 GMT 2025