1 /* $NetBSD: umap_vfsops.c,v 1.88 2012/04/30 22:51:28 rmind 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 1.88 2012/04/30 22:51:28 rmind 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 error = layer_node_create(mp, lowerrootvp, &vp); 209 /* 210 * Make sure the node alias worked 211 */ 212 if (error) { 213 vput(lowerrootvp); 214 hashdone(amp->umapm_node_hashtbl, HASH_LIST, 215 amp->umapm_node_hash); 216 kmem_free(amp, sizeof(struct umap_mount)); 217 return error; 218 } 219 /* 220 * Unlock the node (either the lower or the alias) 221 */ 222 vp->v_vflag |= VV_ROOT; 223 VOP_UNLOCK(vp); 224 225 /* 226 * Keep a held reference to the root vnode. 227 * It is vrele'd in umapfs_unmount. 228 */ 229 amp->umapm_rootvp = vp; 230 231 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 232 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 233 #ifdef UMAPFS_DIAGNOSTIC 234 printf("umapfs_mount: lower %s, alias at %s\n", 235 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 236 #endif 237 return error; 238 } 239 240 /* 241 * Free reference to umap layer 242 */ 243 int 244 umapfs_unmount(struct mount *mp, int mntflags) 245 { 246 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 247 struct vnode *rtvp = amp->umapm_rootvp; 248 int error; 249 int flags = 0; 250 251 #ifdef UMAPFS_DIAGNOSTIC 252 printf("umapfs_unmount(mp = %p)\n", mp); 253 #endif 254 255 if (mntflags & MNT_FORCE) 256 flags |= FORCECLOSE; 257 258 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 259 return (EBUSY); 260 if ((error = vflush(mp, rtvp, flags)) != 0) 261 return (error); 262 263 #ifdef UMAPFS_DIAGNOSTIC 264 vprint("alias root of lower", rtvp); 265 #endif 266 /* 267 * Blow it away for future re-use 268 */ 269 vgone(rtvp); 270 /* 271 * Finally, throw away the umap_mount structure 272 */ 273 mutex_destroy(&->umapm_hashlock); 274 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash); 275 kmem_free(amp, sizeof(struct umap_mount)); 276 mp->mnt_data = NULL; 277 return 0; 278 } 279 280 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 281 282 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 283 &umapfs_vnodeop_opv_desc, 284 NULL, 285 }; 286 287 struct vfsops umapfs_vfsops = { 288 MOUNT_UMAP, 289 sizeof (struct umap_args), 290 umapfs_mount, 291 layerfs_start, 292 umapfs_unmount, 293 layerfs_root, 294 layerfs_quotactl, 295 layerfs_statvfs, 296 layerfs_sync, 297 layerfs_vget, 298 layerfs_fhtovp, 299 layerfs_vptofh, 300 layerfs_init, 301 NULL, 302 layerfs_done, 303 NULL, /* vfs_mountroot */ 304 layerfs_snapshot, 305 vfs_stdextattrctl, 306 (void *)eopnotsupp, /* vfs_suspendctl */ 307 layerfs_renamelock_enter, 308 layerfs_renamelock_exit, 309 (void *)eopnotsupp, 310 umapfs_vnodeopv_descs, 311 0, /* vfs_refcount */ 312 { NULL, NULL }, 313 }; 314 315 static int 316 umap_modcmd(modcmd_t cmd, void *arg) 317 { 318 int error; 319 320 switch (cmd) { 321 case MODULE_CMD_INIT: 322 error = vfs_attach(&umapfs_vfsops); 323 if (error != 0) 324 break; 325 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 326 CTLFLAG_PERMANENT, 327 CTLTYPE_NODE, "vfs", NULL, 328 NULL, 0, NULL, 0, 329 CTL_VFS, CTL_EOL); 330 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 331 CTLFLAG_PERMANENT, 332 CTLTYPE_NODE, "umap", 333 SYSCTL_DESCR("UID/GID remapping file system"), 334 NULL, 0, NULL, 0, 335 CTL_VFS, 10, CTL_EOL); 336 /* 337 * XXX the "10" above could be dynamic, thereby eliminating 338 * one more instance of the "number to vfs" mapping problem, 339 * but "10" is the order as taken from sys/mount.h 340 */ 341 break; 342 case MODULE_CMD_FINI: 343 error = vfs_detach(&umapfs_vfsops); 344 if (error != 0) 345 break; 346 sysctl_teardown(&umapfs_sysctl_log); 347 break; 348 default: 349 error = ENOTTY; 350 break; 351 } 352 353 return (error); 354 } 355