1 /* $NetBSD: umap_vfsops.c,v 1.95 2014/11/09 18:08:07 maxv 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 1.95 2014/11/09 18:08:07 maxv 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/kauth.h> 55 #include <sys/module.h> 56 57 #include <miscfs/umapfs/umap.h> 58 #include <miscfs/genfs/layer_extern.h> 59 60 MODULE(MODULE_CLASS_VFS, umap, "layerfs"); 61 62 VFS_PROTOS(umapfs); 63 64 static struct sysctllog *umapfs_sysctl_log; 65 66 /* 67 * Mount umap layer 68 */ 69 int 70 umapfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 71 { 72 struct lwp *l = curlwp; 73 struct pathbuf *pb; 74 struct nameidata nd; 75 struct umap_args *args = data; 76 struct vnode *lowerrootvp, *vp; 77 struct umap_mount *amp; 78 int error; 79 #ifdef UMAPFS_DIAGNOSTIC 80 int i; 81 #endif 82 83 if (args == NULL) 84 return EINVAL; 85 if (*data_len < sizeof *args) 86 return EINVAL; 87 88 if (mp->mnt_flag & MNT_GETARGS) { 89 amp = MOUNTTOUMAPMOUNT(mp); 90 if (amp == NULL) 91 return EIO; 92 args->la.target = NULL; 93 args->nentries = amp->info_nentries; 94 args->gnentries = amp->info_gnentries; 95 *data_len = sizeof *args; 96 return 0; 97 } 98 99 /* only for root */ 100 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, 101 KAUTH_REQ_SYSTEM_MOUNT_UMAP, NULL, NULL, NULL); 102 if (error) 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 = kmem_zalloc(sizeof(struct umap_mount), KM_SLEEP); 147 mp->mnt_data = amp; 148 amp->umapm_vfs = lowerrootvp->v_mount; 149 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 150 mp->mnt_flag |= MNT_LOCAL; 151 152 /* 153 * Now copy in the number of entries and maps for umap mapping. 154 */ 155 if (args->nentries < 0 || args->nentries > MAPFILEENTRIES || 156 args->gnentries < 0 || args->gnentries > GMAPFILEENTRIES) { 157 vput(lowerrootvp); 158 return (EINVAL); 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_vnodeop_p = umap_vnodeop_p; 201 202 /* 203 * fix up umap node for root vnode. 204 */ 205 VOP_UNLOCK(lowerrootvp); 206 error = layer_node_create(mp, lowerrootvp, &vp); 207 /* 208 * Make sure the node alias worked 209 */ 210 if (error) { 211 vrele(lowerrootvp); 212 kmem_free(amp, sizeof(struct umap_mount)); 213 return error; 214 } 215 216 /* 217 * Keep a held reference to the root vnode. 218 * It is vrele'd in umapfs_unmount. 219 */ 220 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 221 vp->v_vflag |= VV_ROOT; 222 amp->umapm_rootvp = vp; 223 VOP_UNLOCK(vp); 224 225 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 226 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 227 #ifdef UMAPFS_DIAGNOSTIC 228 printf("umapfs_mount: lower %s, alias at %s\n", 229 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 230 #endif 231 return error; 232 } 233 234 /* 235 * Free reference to umap layer 236 */ 237 int 238 umapfs_unmount(struct mount *mp, int mntflags) 239 { 240 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 241 struct vnode *rtvp = amp->umapm_rootvp; 242 int error; 243 int flags = 0; 244 245 #ifdef UMAPFS_DIAGNOSTIC 246 printf("umapfs_unmount(mp = %p)\n", mp); 247 #endif 248 249 if (mntflags & MNT_FORCE) 250 flags |= FORCECLOSE; 251 252 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 253 return (EBUSY); 254 if ((error = vflush(mp, rtvp, flags)) != 0) 255 return (error); 256 257 #ifdef UMAPFS_DIAGNOSTIC 258 vprint("alias root of lower", rtvp); 259 #endif 260 /* 261 * Blow it away for future re-use 262 */ 263 vgone(rtvp); 264 /* 265 * Finally, throw away the umap_mount structure 266 */ 267 kmem_free(amp, sizeof(struct umap_mount)); 268 mp->mnt_data = NULL; 269 return 0; 270 } 271 272 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 273 274 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 275 &umapfs_vnodeop_opv_desc, 276 NULL, 277 }; 278 279 struct vfsops umapfs_vfsops = { 280 .vfs_name = MOUNT_UMAP, 281 .vfs_min_mount_data = sizeof (struct umap_args), 282 .vfs_mount = umapfs_mount, 283 .vfs_start = layerfs_start, 284 .vfs_unmount = umapfs_unmount, 285 .vfs_root = layerfs_root, 286 .vfs_quotactl = layerfs_quotactl, 287 .vfs_statvfs = layerfs_statvfs, 288 .vfs_sync = layerfs_sync, 289 .vfs_loadvnode = layerfs_loadvnode, 290 .vfs_vget = layerfs_vget, 291 .vfs_fhtovp = layerfs_fhtovp, 292 .vfs_vptofh = layerfs_vptofh, 293 .vfs_init = layerfs_init, 294 .vfs_done = layerfs_done, 295 .vfs_snapshot = layerfs_snapshot, 296 .vfs_extattrctl = vfs_stdextattrctl, 297 .vfs_suspendctl = (void *)eopnotsupp, 298 .vfs_renamelock_enter = layerfs_renamelock_enter, 299 .vfs_renamelock_exit = layerfs_renamelock_exit, 300 .vfs_fsync = (void *)eopnotsupp, 301 .vfs_opv_descs = umapfs_vnodeopv_descs 302 }; 303 304 static int 305 umap_modcmd(modcmd_t cmd, void *arg) 306 { 307 int error; 308 309 switch (cmd) { 310 case MODULE_CMD_INIT: 311 error = vfs_attach(&umapfs_vfsops); 312 if (error != 0) 313 break; 314 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 315 CTLFLAG_PERMANENT, 316 CTLTYPE_NODE, "umap", 317 SYSCTL_DESCR("UID/GID remapping file system"), 318 NULL, 0, NULL, 0, 319 CTL_VFS, 10, CTL_EOL); 320 /* 321 * XXX the "10" above could be dynamic, thereby eliminating 322 * one more instance of the "number to vfs" mapping problem, 323 * but "10" is the order as taken from sys/mount.h 324 */ 325 break; 326 case MODULE_CMD_FINI: 327 error = vfs_detach(&umapfs_vfsops); 328 if (error != 0) 329 break; 330 sysctl_teardown(&umapfs_sysctl_log); 331 break; 332 default: 333 error = ENOTTY; 334 break; 335 } 336 337 return (error); 338 } 339