1/* $NetBSD: umap_vfsops.c,v 1.86.20.1 2014/04/21 10:17:48 bouyer 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 1.86.20.1 2014/04/21 10:17:48 bouyer 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 61MODULE(MODULE_CLASS_VFS, umap, "layerfs"); 62 63VFS_PROTOS(umapfs); 64 65static struct sysctllog *umapfs_sysctl_log; 66 67/* 68 * Mount umap layer 69 */ 70int 71umapfs_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 (args == NULL) 85 return EINVAL; 86 if (*data_len < sizeof *args) 87 return EINVAL; 88 89 if (mp->mnt_flag & MNT_GETARGS) { 90 amp = MOUNTTOUMAPMOUNT(mp); 91 if (amp == NULL) 92 return EIO; 93 args->la.target = NULL; 94 args->nentries = amp->info_nentries; 95 args->gnentries = amp->info_gnentries; 96 *data_len = sizeof *args; 97 return 0; 98 } 99 100 /* only for root */ 101 if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, 102 NULL)) != 0) 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 = (struct umap_mount *) malloc(sizeof(struct umap_mount), 147 M_UFSMNT, M_WAITOK); /* XXX */ 148 memset(amp, 0, sizeof(struct umap_mount)); 149 150 mp->mnt_data = amp; 151 amp->umapm_vfs = lowerrootvp->v_mount; 152 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 153 mp->mnt_flag |= MNT_LOCAL; 154 155 /* 156 * Now copy in the number of entries and maps for umap mapping. 157 */ 158 if (args->nentries < 0 || args->nentries > MAPFILEENTRIES || 159 args->gnentries < 0 || args->gnentries > GMAPFILEENTRIES) { 160 vput(lowerrootvp); 161 return (EINVAL); 162 } 163 164 amp->info_nentries = args->nentries; 165 amp->info_gnentries = args->gnentries; 166 error = copyin(args->mapdata, amp->info_mapdata, 167 2*sizeof(u_long)*args->nentries); 168 if (error) { 169 vput(lowerrootvp); 170 return (error); 171 } 172 173#ifdef UMAPFS_DIAGNOSTIC 174 printf("umap_mount:nentries %d\n",args->nentries); 175 for (i = 0; i < args->nentries; i++) 176 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 177 amp->info_mapdata[i][1]); 178#endif 179 180 error = copyin(args->gmapdata, amp->info_gmapdata, 181 2*sizeof(u_long)*args->gnentries); 182 if (error) { 183 vput(lowerrootvp); 184 return (error); 185 } 186 187#ifdef UMAPFS_DIAGNOSTIC 188 printf("umap_mount:gnentries %d\n",args->gnentries); 189 for (i = 0; i < args->gnentries; i++) 190 printf("\tgroup %ld maps to %ld\n", 191 amp->info_gmapdata[i][0], 192 amp->info_gmapdata[i][1]); 193#endif 194 195 /* 196 * Make sure the mount point's sufficiently initialized 197 * that the node create call will work. 198 */ 199 vfs_getnewfsid(mp); 200 amp->umapm_size = sizeof(struct umap_node); 201 amp->umapm_tag = VT_UMAP; 202 amp->umapm_bypass = umap_bypass; 203 amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */ 204 amp->umapm_vnodeop_p = umap_vnodeop_p; 205 mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE); 206 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true, 207 &->umapm_node_hash); 208 209 210 /* 211 * fix up umap node for root vnode. 212 */ 213 error = layer_node_create(mp, lowerrootvp, &vp); 214 /* 215 * Make sure the node alias worked 216 */ 217 if (error) { 218 vput(lowerrootvp); 219 hashdone(amp->umapm_node_hashtbl, HASH_LIST, 220 amp->umapm_node_hash); 221 free(amp, M_UFSMNT); /* XXX */ 222 return (error); 223 } 224 /* 225 * Unlock the node (either the lower or the alias) 226 */ 227 vp->v_vflag |= VV_ROOT; 228 VOP_UNLOCK(vp); 229 230 /* 231 * Keep a held reference to the root vnode. 232 * It is vrele'd in umapfs_unmount. 233 */ 234 amp->umapm_rootvp = vp; 235 236 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 237 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 238#ifdef UMAPFS_DIAGNOSTIC 239 printf("umapfs_mount: lower %s, alias at %s\n", 240 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 241#endif 242 return error; 243} 244 245/* 246 * Free reference to umap layer 247 */ 248int 249umapfs_unmount(struct mount *mp, int mntflags) 250{ 251 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 252 struct vnode *rtvp = amp->umapm_rootvp; 253 int error; 254 int flags = 0; 255 256#ifdef UMAPFS_DIAGNOSTIC 257 printf("umapfs_unmount(mp = %p)\n", mp); 258#endif 259 260 if (mntflags & MNT_FORCE) 261 flags |= FORCECLOSE; 262 263 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 264 return (EBUSY); 265 if ((error = vflush(mp, rtvp, flags)) != 0) 266 return (error); 267 268#ifdef UMAPFS_DIAGNOSTIC 269 vprint("alias root of lower", rtvp); 270#endif 271 /* 272 * Blow it away for future re-use 273 */ 274 vgone(rtvp); 275 /* 276 * Finally, throw away the umap_mount structure 277 */ 278 mutex_destroy(&->umapm_hashlock); 279 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash); 280 free(amp, M_UFSMNT); /* XXX */ 281 mp->mnt_data = NULL; 282 return (0); 283} 284 285extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 286 287const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 288 &umapfs_vnodeop_opv_desc, 289 NULL, 290}; 291 292struct vfsops umapfs_vfsops = { 293 MOUNT_UMAP, 294 sizeof (struct umap_args), 295 umapfs_mount, 296 layerfs_start, 297 umapfs_unmount, 298 layerfs_root, 299 layerfs_quotactl, 300 layerfs_statvfs, 301 layerfs_sync, 302 layerfs_vget, 303 layerfs_fhtovp, 304 layerfs_vptofh, 305 layerfs_init, 306 NULL, 307 layerfs_done, 308 NULL, /* vfs_mountroot */ 309 layerfs_snapshot, 310 vfs_stdextattrctl, 311 (void *)eopnotsupp, /* vfs_suspendctl */ 312 layerfs_renamelock_enter, 313 layerfs_renamelock_exit, 314 (void *)eopnotsupp, 315 umapfs_vnodeopv_descs, 316 0, /* vfs_refcount */ 317 { NULL, NULL }, 318}; 319 320static int 321umap_modcmd(modcmd_t cmd, void *arg) 322{ 323 int error; 324 325 switch (cmd) { 326 case MODULE_CMD_INIT: 327 error = vfs_attach(&umapfs_vfsops); 328 if (error != 0) 329 break; 330 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 331 CTLFLAG_PERMANENT, 332 CTLTYPE_NODE, "vfs", NULL, 333 NULL, 0, NULL, 0, 334 CTL_VFS, CTL_EOL); 335 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 336 CTLFLAG_PERMANENT, 337 CTLTYPE_NODE, "umap", 338 SYSCTL_DESCR("UID/GID remapping file system"), 339 NULL, 0, NULL, 0, 340 CTL_VFS, 10, CTL_EOL); 341 /* 342 * XXX the "10" above could be dynamic, thereby eliminating 343 * one more instance of the "number to vfs" mapping problem, 344 * but "10" is the order as taken from sys/mount.h 345 */ 346 break; 347 case MODULE_CMD_FINI: 348 error = vfs_detach(&umapfs_vfsops); 349 if (error != 0) 350 break; 351 sysctl_teardown(&umapfs_sysctl_log); 352 break; 353 default: 354 error = ENOTTY; 355 break; 356 } 357 358 return (error); 359} 360