umap_vfsops.c revision 1.92
1 /* $NetBSD: umap_vfsops.c,v 1.92 2014/04/16 18:55:19 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 1.92 2014/04/16 18:55:19 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/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 (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 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, 102 KAUTH_REQ_SYSTEM_MOUNT_UMAP, NULL, NULL, NULL); 103 if (error) 104 return error; 105 106 #ifdef UMAPFS_DIAGNOSTIC 107 printf("umapfs_mount(mp = %p)\n", mp); 108 #endif 109 110 /* 111 * Update is not supported 112 */ 113 if (mp->mnt_flag & MNT_UPDATE) 114 return EOPNOTSUPP; 115 116 /* 117 * Find lower node 118 */ 119 error = pathbuf_copyin(args->umap_target, &pb); 120 if (error) { 121 return error; 122 } 123 NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); 124 if ((error = namei(&nd)) != 0) { 125 pathbuf_destroy(pb); 126 return error; 127 } 128 129 /* 130 * Sanity check on lower vnode 131 */ 132 lowerrootvp = nd.ni_vp; 133 pathbuf_destroy(pb); 134 #ifdef UMAPFS_DIAGNOSTIC 135 printf("vp = %p, check for VDIR...\n", lowerrootvp); 136 #endif 137 138 if (lowerrootvp->v_type != VDIR) { 139 vput(lowerrootvp); 140 return (EINVAL); 141 } 142 143 #ifdef UMAPFS_DIAGNOSTIC 144 printf("mp = %p\n", mp); 145 #endif 146 147 amp = kmem_zalloc(sizeof(struct umap_mount), KM_SLEEP); 148 mp->mnt_data = amp; 149 amp->umapm_vfs = lowerrootvp->v_mount; 150 if (amp->umapm_vfs->mnt_flag & MNT_LOCAL) 151 mp->mnt_flag |= MNT_LOCAL; 152 153 /* 154 * Now copy in the number of entries and maps for umap mapping. 155 */ 156 if (args->nentries > MAPFILEENTRIES || args->gnentries > GMAPFILEENTRIES) { 157 vput(lowerrootvp); 158 return (error); 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_alloc = layer_node_alloc; /* the default alloc is fine */ 201 amp->umapm_vnodeop_p = umap_vnodeop_p; 202 mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE); 203 amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true, 204 &->umapm_node_hash); 205 206 207 /* 208 * fix up umap node for root vnode. 209 */ 210 VOP_UNLOCK(lowerrootvp); 211 error = layer_node_create(mp, lowerrootvp, &vp); 212 /* 213 * Make sure the node alias worked 214 */ 215 if (error) { 216 vrele(lowerrootvp); 217 hashdone(amp->umapm_node_hashtbl, HASH_LIST, 218 amp->umapm_node_hash); 219 kmem_free(amp, sizeof(struct umap_mount)); 220 return error; 221 } 222 223 /* 224 * Keep a held reference to the root vnode. 225 * It is vrele'd in umapfs_unmount. 226 */ 227 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 228 vp->v_vflag |= VV_ROOT; 229 amp->umapm_rootvp = vp; 230 VOP_UNLOCK(vp); 231 232 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 233 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 234 #ifdef UMAPFS_DIAGNOSTIC 235 printf("umapfs_mount: lower %s, alias at %s\n", 236 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 237 #endif 238 return error; 239 } 240 241 /* 242 * Free reference to umap layer 243 */ 244 int 245 umapfs_unmount(struct mount *mp, int mntflags) 246 { 247 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 248 struct vnode *rtvp = amp->umapm_rootvp; 249 int error; 250 int flags = 0; 251 252 #ifdef UMAPFS_DIAGNOSTIC 253 printf("umapfs_unmount(mp = %p)\n", mp); 254 #endif 255 256 if (mntflags & MNT_FORCE) 257 flags |= FORCECLOSE; 258 259 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 260 return (EBUSY); 261 if ((error = vflush(mp, rtvp, flags)) != 0) 262 return (error); 263 264 #ifdef UMAPFS_DIAGNOSTIC 265 vprint("alias root of lower", rtvp); 266 #endif 267 /* 268 * Blow it away for future re-use 269 */ 270 vgone(rtvp); 271 /* 272 * Finally, throw away the umap_mount structure 273 */ 274 mutex_destroy(&->umapm_hashlock); 275 hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash); 276 kmem_free(amp, sizeof(struct umap_mount)); 277 mp->mnt_data = NULL; 278 return 0; 279 } 280 281 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 282 283 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 284 &umapfs_vnodeop_opv_desc, 285 NULL, 286 }; 287 288 struct vfsops umapfs_vfsops = { 289 .vfs_name = MOUNT_UMAP, 290 .vfs_min_mount_data = sizeof (struct umap_args), 291 .vfs_mount = umapfs_mount, 292 .vfs_start = layerfs_start, 293 .vfs_unmount = umapfs_unmount, 294 .vfs_root = layerfs_root, 295 .vfs_quotactl = layerfs_quotactl, 296 .vfs_statvfs = layerfs_statvfs, 297 .vfs_sync = layerfs_sync, 298 .vfs_vget = layerfs_vget, 299 .vfs_fhtovp = layerfs_fhtovp, 300 .vfs_vptofh = layerfs_vptofh, 301 .vfs_init = layerfs_init, 302 .vfs_done = layerfs_done, 303 .vfs_snapshot = layerfs_snapshot, 304 .vfs_extattrctl = vfs_stdextattrctl, 305 .vfs_suspendctl = (void *)eopnotsupp, 306 .vfs_renamelock_enter = layerfs_renamelock_enter, 307 .vfs_renamelock_exit = layerfs_renamelock_exit, 308 .vfs_fsync = (void *)eopnotsupp, 309 .vfs_opv_descs = umapfs_vnodeopv_descs 310 }; 311 312 static int 313 umap_modcmd(modcmd_t cmd, void *arg) 314 { 315 int error; 316 317 switch (cmd) { 318 case MODULE_CMD_INIT: 319 error = vfs_attach(&umapfs_vfsops); 320 if (error != 0) 321 break; 322 sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL, 323 CTLFLAG_PERMANENT, 324 CTLTYPE_NODE, "umap", 325 SYSCTL_DESCR("UID/GID remapping file system"), 326 NULL, 0, NULL, 0, 327 CTL_VFS, 10, CTL_EOL); 328 /* 329 * XXX the "10" above could be dynamic, thereby eliminating 330 * one more instance of the "number to vfs" mapping problem, 331 * but "10" is the order as taken from sys/mount.h 332 */ 333 break; 334 case MODULE_CMD_FINI: 335 error = vfs_detach(&umapfs_vfsops); 336 if (error != 0) 337 break; 338 sysctl_teardown(&umapfs_sysctl_log); 339 break; 340 default: 341 error = ENOTTY; 342 break; 343 } 344 345 return (error); 346 } 347
Indexes created Sun Sep 21 20:09:37 GMT 2025