1 /* $NetBSD: umap_vfsops.c,v 1.90 2014/02/25 18:30:12 pooka 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 1.90 2014/02/25 18:30:12 pooka 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 = kmem_zalloc(sizeof(struct umap_mount), KM_SLEEP); 146 mp->mnt_data = amp; 147 amp->umapm_vfs = lowerrootvp->v_mount; 148 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 149 mp->mnt_flag |= MNT_LOCAL; 150 151 /* 152 * Now copy in the number of entries and maps for umap mapping. 153 */ 154 if (args->nentries > MAPFILEENTRIES || args->gnentries > GMAPFILEENTRIES) { 155 vput(lowerrootvp); 156 return (error); 157 } 158 159 amp->info_nentries = args->nentries; 160 amp->info_gnentries = args->gnentries; 161 error = copyin(args->mapdata, amp->info_mapdata, 162 2*sizeof(u_long)*args->nentries); 163 if (error) { 164 vput(lowerrootvp); 165 return (error); 166 } 167 168 #ifdef UMAPFS_DIAGNOSTIC 169 printf("umap_mount:nentries %d\n",args->nentries); 170 for (i = 0; i < args->nentries; i++) 171 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 172 amp->info_mapdata[i][1]); 173 #endif 174 175 error = copyin(args->gmapdata, amp->info_gmapdata, 176 2*sizeof(u_long)*args->gnentries); 177 if (error) { 178 vput(lowerrootvp); 179 return (error); 180 } 181 182 #ifdef UMAPFS_DIAGNOSTIC 183 printf("umap_mount:gnentries %d\n",args->gnentries); 184 for (i = 0; i < args->gnentries; i++) 185 printf("\tgroup %ld maps to %ld\n", 186 amp->info_gmapdata[i][0], 187 amp->info_gmapdata[i][1]); 188 #endif 189 190 /* 191 * Make sure the mount point's sufficiently initialized 192 * that the node create call will work. 193 */ 194 vfs_getnewfsid(mp); 195 amp->umapm_size = sizeof(struct umap_node); 196 amp->umapm_tag = VT_UMAP; 197 amp->umapm_bypass = umap_bypass; 198 amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */ 199 amp->umapm_vnodeop_p = umap_vnodeop_p; 200 mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE); 201 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true, 202 &->umapm_node_hash); 203 204 205 /* 206 * fix up umap node for root vnode. 207 */ 208 VOP_UNLOCK(lowerrootvp); 209 error = layer_node_create(mp, lowerrootvp, &vp); 210 /* 211 * Make sure the node alias worked 212 */ 213 if (error) { 214 vrele(lowerrootvp); 215 hashdone(amp->umapm_node_hashtbl, HASH_LIST, 216 amp->umapm_node_hash); 217 kmem_free(amp, sizeof(struct umap_mount)); 218 return error; 219 } 220 221 /* 222 * Keep a held reference to the root vnode. 223 * It is vrele'd in umapfs_unmount. 224 */ 225 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 226 vp->v_vflag |= VV_ROOT; 227 amp->umapm_rootvp = vp; 228 VOP_UNLOCK(vp); 229 230 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 231 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 232 #ifdef UMAPFS_DIAGNOSTIC 233 printf("umapfs_mount: lower %s, alias at %s\n", 234 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 235 #endif 236 return error; 237 } 238 239 /* 240 * Free reference to umap layer 241 */ 242 int 243 umapfs_unmount(struct mount *mp, int mntflags) 244 { 245 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 246 struct vnode *rtvp = amp->umapm_rootvp; 247 int error; 248 int flags = 0; 249 250 #ifdef UMAPFS_DIAGNOSTIC 251 printf("umapfs_unmount(mp = %p)\n", mp); 252 #endif 253 254 if (mntflags & MNT_FORCE) 255 flags |= FORCECLOSE; 256 257 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 258 return (EBUSY); 259 if ((error = vflush(mp, rtvp, flags)) != 0) 260 return (error); 261 262 #ifdef UMAPFS_DIAGNOSTIC 263 vprint("alias root of lower", rtvp); 264 #endif 265 /* 266 * Blow it away for future re-use 267 */ 268 vgone(rtvp); 269 /* 270 * Finally, throw away the umap_mount structure 271 */ 272 mutex_destroy(&->umapm_hashlock); 273 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash); 274 kmem_free(amp, sizeof(struct umap_mount)); 275 mp->mnt_data = NULL; 276 return 0; 277 } 278 279 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 280 281 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 282 &umapfs_vnodeop_opv_desc, 283 NULL, 284 }; 285 286 struct vfsops umapfs_vfsops = { 287 MOUNT_UMAP, 288 sizeof (struct umap_args), 289 umapfs_mount, 290 layerfs_start, 291 umapfs_unmount, 292 layerfs_root, 293 layerfs_quotactl, 294 layerfs_statvfs, 295 layerfs_sync, 296 layerfs_vget, 297 layerfs_fhtovp, 298 layerfs_vptofh, 299 layerfs_init, 300 NULL, 301 layerfs_done, 302 NULL, /* vfs_mountroot */ 303 layerfs_snapshot, 304 vfs_stdextattrctl, 305 (void *)eopnotsupp, /* vfs_suspendctl */ 306 layerfs_renamelock_enter, 307 layerfs_renamelock_exit, 308 (void *)eopnotsupp, 309 umapfs_vnodeopv_descs, 310 0, /* vfs_refcount */ 311 { NULL, NULL }, 312 }; 313 314 static int 315 umap_modcmd(modcmd_t cmd, void *arg) 316 { 317 int error; 318 319 switch (cmd) { 320 case MODULE_CMD_INIT: 321 error = vfs_attach(&umapfs_vfsops); 322 if (error != 0) 323 break; 324 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 325 CTLFLAG_PERMANENT, 326 CTLTYPE_NODE, "umap", 327 SYSCTL_DESCR("UID/GID remapping file system"), 328 NULL, 0, NULL, 0, 329 CTL_VFS, 10, CTL_EOL); 330 /* 331 * XXX the "10" above could be dynamic, thereby eliminating 332 * one more instance of the "number to vfs" mapping problem, 333 * but "10" is the order as taken from sys/mount.h 334 */ 335 break; 336 case MODULE_CMD_FINI: 337 error = vfs_detach(&umapfs_vfsops); 338 if (error != 0) 339 break; 340 sysctl_teardown(&umapfs_sysctl_log); 341 break; 342 default: 343 error = ENOTTY; 344 break; 345 } 346 347 return (error); 348 } 349