1 /* $NetBSD: umap_vfsops.c,v 1.59 2006/09/03 22:28:53 christos 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 1.59 2006/09/03 22:28:53 christos 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 57 #include <miscfs/umapfs/umap.h> 58 #include <miscfs/genfs/layer_extern.h> 59 60 int umapfs_mount(struct mount *, const char *, void *, 61 struct nameidata *, struct lwp *); 62 int umapfs_unmount(struct mount *, int, struct lwp *); 63 64 /* 65 * Mount umap layer 66 */ 67 int 68 umapfs_mount(mp, path, data, ndp, l) 69 struct mount *mp; 70 const char *path; 71 void *data; 72 struct nameidata *ndp; 73 struct lwp *l; 74 { 75 struct umap_args args; 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 (mp->mnt_flag & MNT_GETARGS) { 84 amp = MOUNTTOUMAPMOUNT(mp); 85 if (amp == NULL) 86 return EIO; 87 args.la.target = NULL; 88 args.nentries = amp->info_nentries; 89 args.gnentries = amp->info_gnentries; 90 return copyout(&args, data, sizeof(args)); 91 } 92 93 /* only for root */ 94 if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, 95 &l->l_acflag)) != 0) 96 return error; 97 98 #ifdef UMAPFS_DIAGNOSTIC 99 printf("umapfs_mount(mp = %p)\n", mp); 100 #endif 101 102 /* 103 * Get argument 104 */ 105 error = copyin(data, &args, sizeof(struct umap_args)); 106 if (error) 107 return (error); 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 NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF, 119 UIO_USERSPACE, args.umap_target, l); 120 if ((error = namei(ndp)) != 0) 121 return (error); 122 123 /* 124 * Sanity check on lower vnode 125 */ 126 lowerrootvp = ndp->ni_vp; 127 #ifdef UMAPFS_DIAGNOSTIC 128 printf("vp = %p, check for VDIR...\n", lowerrootvp); 129 #endif 130 131 if (lowerrootvp->v_type != VDIR) { 132 vput(lowerrootvp); 133 return (EINVAL); 134 } 135 136 #ifdef UMAPFS_DIAGNOSTIC 137 printf("mp = %p\n", mp); 138 #endif 139 140 amp = (struct umap_mount *) malloc(sizeof(struct umap_mount), 141 M_UFSMNT, M_WAITOK); /* XXX */ 142 memset(amp, 0, sizeof(struct umap_mount)); 143 144 mp->mnt_data = amp; 145 mp->mnt_leaf = lowerrootvp->v_mount->mnt_leaf; 146 amp->umapm_vfs = lowerrootvp->v_mount; 147 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 148 mp->mnt_flag |= MNT_LOCAL; 149 150 /* 151 * Now copy in the number of entries and maps for umap mapping. 152 */ 153 if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) { 154 vput(lowerrootvp); 155 return (error); 156 } 157 158 amp->info_nentries = args.nentries; 159 amp->info_gnentries = args.gnentries; 160 error = copyin(args.mapdata, amp->info_mapdata, 161 2*sizeof(u_long)*args.nentries); 162 if (error) { 163 vput(lowerrootvp); 164 return (error); 165 } 166 167 #ifdef UMAPFS_DIAGNOSTIC 168 printf("umap_mount:nentries %d\n",args.nentries); 169 for (i = 0; i < args.nentries; i++) 170 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 171 amp->info_mapdata[i][1]); 172 #endif 173 174 error = copyin(args.gmapdata, amp->info_gmapdata, 175 2*sizeof(u_long)*args.gnentries); 176 if (error) { 177 vput(lowerrootvp); 178 return (error); 179 } 180 181 #ifdef UMAPFS_DIAGNOSTIC 182 printf("umap_mount:gnentries %d\n",args.gnentries); 183 for (i = 0; i < args.gnentries; i++) 184 printf("\tgroup %ld maps to %ld\n", 185 amp->info_gmapdata[i][0], 186 amp->info_gmapdata[i][1]); 187 #endif 188 189 /* 190 * Make sure the mount point's sufficiently initialized 191 * that the node create call will work. 192 */ 193 vfs_getnewfsid(mp); 194 amp->umapm_size = sizeof(struct umap_node); 195 amp->umapm_tag = VT_UMAP; 196 amp->umapm_bypass = umap_bypass; 197 amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */ 198 amp->umapm_vnodeop_p = umap_vnodeop_p; 199 simple_lock_init(&->umapm_hashlock); 200 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE, 201 M_WAITOK, &->umapm_node_hash); 202 203 204 /* 205 * fix up umap node for root vnode. 206 */ 207 error = layer_node_create(mp, lowerrootvp, &vp); 208 /* 209 * Make sure the node alias worked 210 */ 211 if (error) { 212 vput(lowerrootvp); 213 free(amp, M_UFSMNT); /* XXX */ 214 return (error); 215 } 216 /* 217 * Unlock the node (either the lower or the alias) 218 */ 219 VOP_UNLOCK(vp, 0); 220 221 /* 222 * Keep a held reference to the root vnode. 223 * It is vrele'd in umapfs_unmount. 224 */ 225 vp->v_flag |= VROOT; 226 amp->umapm_rootvp = vp; 227 228 error = set_statvfs_info(path, UIO_USERSPACE, args.umap_target, 229 UIO_USERSPACE, mp, l); 230 #ifdef UMAPFS_DIAGNOSTIC 231 printf("umapfs_mount: lower %s, alias at %s\n", 232 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 233 #endif 234 return error; 235 } 236 237 /* 238 * Free reference to umap layer 239 */ 240 int 241 umapfs_unmount(mp, mntflags, l) 242 struct mount *mp; 243 int mntflags; 244 struct lwp *l; 245 { 246 struct vnode *rtvp = MOUNTTOUMAPMOUNT(mp)->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 /* 258 * Clear out buffer cache. I don't think we 259 * ever get anything cached at this level at the 260 * moment, but who knows... 261 */ 262 #ifdef notyet 263 mntflushbuf(mp, 0); 264 if (mntinvalbuf(mp, 1)) 265 return (EBUSY); 266 #endif 267 if (rtvp->v_usecount > 1) 268 return (EBUSY); 269 if ((error = vflush(mp, rtvp, flags)) != 0) 270 return (error); 271 272 #ifdef UMAPFS_DIAGNOSTIC 273 vprint("alias root of lower", rtvp); 274 #endif 275 /* 276 * Release reference on underlying root vnode 277 */ 278 vrele(rtvp); 279 /* 280 * And blow it away for future re-use 281 */ 282 vgone(rtvp); 283 /* 284 * Finally, throw away the umap_mount structure 285 */ 286 free(mp->mnt_data, M_UFSMNT); /* XXX */ 287 mp->mnt_data = 0; 288 return (0); 289 } 290 291 SYSCTL_SETUP(sysctl_vfs_umap_setup, "sysctl vfs.umap subtree setup") 292 { 293 294 sysctl_createv(clog, 0, NULL, NULL, 295 CTLFLAG_PERMANENT, 296 CTLTYPE_NODE, "vfs", NULL, 297 NULL, 0, NULL, 0, 298 CTL_VFS, CTL_EOL); 299 sysctl_createv(clog, 0, NULL, NULL, 300 CTLFLAG_PERMANENT, 301 CTLTYPE_NODE, "umap", 302 SYSCTL_DESCR("UID/GID remapping file system"), 303 NULL, 0, NULL, 0, 304 CTL_VFS, 10, CTL_EOL); 305 /* 306 * XXX the "10" above could be dynamic, thereby eliminating 307 * one more instance of the "number to vfs" mapping problem, 308 * but "10" is the order as taken from sys/mount.h 309 */ 310 } 311 312 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 313 314 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 315 &umapfs_vnodeop_opv_desc, 316 NULL, 317 }; 318 319 struct vfsops umapfs_vfsops = { 320 MOUNT_UMAP, 321 umapfs_mount, 322 layerfs_start, 323 umapfs_unmount, 324 layerfs_root, 325 layerfs_quotactl, 326 layerfs_statvfs, 327 layerfs_sync, 328 layerfs_vget, 329 layerfs_fhtovp, 330 layerfs_vptofh, 331 layerfs_init, 332 NULL, 333 layerfs_done, 334 NULL, /* vfs_mountroot */ 335 layerfs_snapshot, 336 vfs_stdextattrctl, 337 umapfs_vnodeopv_descs, 338 0, /* vfs_refcount */ 339 { NULL, NULL }, 340 }; 341 VFS_ATTACH(umapfs_vfsops); 342