| 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 | |