umap_vfsops.c revision 1.99.12.2
1 /* $NetBSD: umap_vfsops.c,v 1.99.12.2 2020/04/08 14:08:54 martin 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 1.99.12.2 2020/04/08 14:08:54 martin 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/kauth.h> 55 #include <sys/module.h> 56 57 #include <miscfs/umapfs/umap.h> 58 #include <miscfs/genfs/layer_extern.h> 59 60 MODULE(MODULE_CLASS_VFS, umap, "layerfs"); 61 62 VFS_PROTOS(umapfs); 63 64 /* 65 * Mount umap layer 66 */ 67 int 68 umapfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 69 { 70 struct lwp *l = curlwp; 71 struct pathbuf *pb; 72 struct nameidata nd; 73 struct umap_args *args = data; 74 struct vnode *lowerrootvp, *vp; 75 struct umap_mount *amp; 76 int error; 77 #ifdef UMAPFS_DIAGNOSTIC 78 int i; 79 #endif 80 81 if (args == NULL) 82 return EINVAL; 83 if (*data_len < sizeof *args) 84 return EINVAL; 85 86 if (mp->mnt_flag & MNT_GETARGS) { 87 amp = MOUNTTOUMAPMOUNT(mp); 88 if (amp == NULL) 89 return EIO; 90 args->la.target = NULL; 91 args->nentries = amp->info_nentries; 92 args->gnentries = amp->info_gnentries; 93 *data_len = sizeof *args; 94 return 0; 95 } 96 97 /* only for root */ 98 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, 99 KAUTH_REQ_SYSTEM_MOUNT_UMAP, NULL, NULL, NULL); 100 if (error) 101 return error; 102 103 #ifdef UMAPFS_DIAGNOSTIC 104 printf("umapfs_mount(mp = %p)\n", mp); 105 #endif 106 107 /* 108 * Update is not supported 109 */ 110 if (mp->mnt_flag & MNT_UPDATE) 111 return EOPNOTSUPP; 112 113 /* 114 * Find lower node 115 */ 116 error = pathbuf_copyin(args->umap_target, &pb); 117 if (error) { 118 return error; 119 } 120 NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); 121 if ((error = namei(&nd)) != 0) { 122 pathbuf_destroy(pb); 123 return error; 124 } 125 126 /* 127 * Sanity check on lower vnode 128 */ 129 lowerrootvp = nd.ni_vp; 130 pathbuf_destroy(pb); 131 #ifdef UMAPFS_DIAGNOSTIC 132 printf("vp = %p, check for VDIR...\n", lowerrootvp); 133 #endif 134 135 if (lowerrootvp->v_type != VDIR) { 136 vput(lowerrootvp); 137 return (EINVAL); 138 } 139 140 #ifdef UMAPFS_DIAGNOSTIC 141 printf("mp = %p\n", mp); 142 #endif 143 144 amp = kmem_zalloc(sizeof(struct umap_mount), KM_SLEEP); 145 mp->mnt_data = amp; 146 147 /* 148 * Now copy in the number of entries and maps for umap mapping. 149 */ 150 if (args->nentries < 0 || args->nentries > MAPFILEENTRIES || 151 args->gnentries < 0 || args->gnentries > GMAPFILEENTRIES) { 152 vput(lowerrootvp); 153 return (EINVAL); 154 } 155 156 amp->info_nentries = args->nentries; 157 amp->info_gnentries = args->gnentries; 158 error = copyin(args->mapdata, amp->info_mapdata, 159 2*sizeof(u_long)*args->nentries); 160 if (error) { 161 vput(lowerrootvp); 162 return (error); 163 } 164 165 #ifdef UMAPFS_DIAGNOSTIC 166 printf("umap_mount:nentries %d\n",args->nentries); 167 for (i = 0; i < args->nentries; i++) 168 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 169 amp->info_mapdata[i][1]); 170 #endif 171 172 error = copyin(args->gmapdata, amp->info_gmapdata, 173 2*sizeof(u_long)*args->gnentries); 174 if (error) { 175 vput(lowerrootvp); 176 return (error); 177 } 178 179 #ifdef UMAPFS_DIAGNOSTIC 180 printf("umap_mount:gnentries %d\n",args->gnentries); 181 for (i = 0; i < args->gnentries; i++) 182 printf("\tgroup %ld maps to %ld\n", 183 amp->info_gmapdata[i][0], 184 amp->info_gmapdata[i][1]); 185 #endif 186 187 /* 188 * Make sure the mount point's sufficiently initialized 189 * that the node create call will work. 190 */ 191 vfs_getnewfsid(mp); 192 mp->mnt_lower = lowerrootvp->v_mount; 193 194 amp->umapm_size = sizeof(struct umap_node); 195 amp->umapm_tag = VT_UMAP; 196 amp->umapm_bypass = umap_bypass; 197 amp->umapm_vnodeop_p = umap_vnodeop_p; 198 199 /* 200 * fix up umap node for root vnode. 201 */ 202 VOP_UNLOCK(lowerrootvp); 203 error = layer_node_create(mp, lowerrootvp, &vp); 204 /* 205 * Make sure the node alias worked 206 */ 207 if (error) { 208 vrele(lowerrootvp); 209 kmem_free(amp, sizeof(struct umap_mount)); 210 return error; 211 } 212 213 /* 214 * Keep a held reference to the root vnode. 215 * It is vrele'd in umapfs_unmount. 216 */ 217 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 218 vp->v_vflag |= VV_ROOT; 219 amp->umapm_rootvp = vp; 220 VOP_UNLOCK(vp); 221 222 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 223 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 224 if (error) 225 return error; 226 227 if (mp->mnt_lower->mnt_flag & MNT_LOCAL) 228 mp->mnt_flag |= MNT_LOCAL; 229 #ifdef UMAPFS_DIAGNOSTIC 230 printf("umapfs_mount: lower %s, alias at %s\n", 231 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 232 #endif 233 return 0; 234 } 235 236 /* 237 * Free reference to umap layer 238 */ 239 int 240 umapfs_unmount(struct mount *mp, int mntflags) 241 { 242 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 243 struct vnode *rtvp = amp->umapm_rootvp; 244 int error; 245 int flags = 0; 246 247 #ifdef UMAPFS_DIAGNOSTIC 248 printf("umapfs_unmount(mp = %p)\n", mp); 249 #endif 250 251 if (mntflags & MNT_FORCE) 252 flags |= FORCECLOSE; 253 254 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 255 return (EBUSY); 256 if ((error = vflush(mp, rtvp, flags)) != 0) 257 return (error); 258 259 #ifdef UMAPFS_DIAGNOSTIC 260 vprint("alias root of lower", rtvp); 261 #endif 262 /* 263 * Blow it away for future re-use 264 */ 265 vgone(rtvp); 266 /* 267 * Finally, throw away the umap_mount structure 268 */ 269 kmem_free(amp, sizeof(struct umap_mount)); 270 mp->mnt_data = NULL; 271 return 0; 272 } 273 274 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 275 276 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 277 &umapfs_vnodeop_opv_desc, 278 NULL, 279 }; 280 281 struct vfsops umapfs_vfsops = { 282 .vfs_name = MOUNT_UMAP, 283 .vfs_min_mount_data = sizeof (struct umap_args), 284 .vfs_mount = umapfs_mount, 285 .vfs_start = layerfs_start, 286 .vfs_unmount = umapfs_unmount, 287 .vfs_root = layerfs_root, 288 .vfs_quotactl = layerfs_quotactl, 289 .vfs_statvfs = layerfs_statvfs, 290 .vfs_sync = layerfs_sync, 291 .vfs_loadvnode = layerfs_loadvnode, 292 .vfs_vget = layerfs_vget, 293 .vfs_fhtovp = layerfs_fhtovp, 294 .vfs_vptofh = layerfs_vptofh, 295 .vfs_init = layerfs_init, 296 .vfs_done = layerfs_done, 297 .vfs_snapshot = layerfs_snapshot, 298 .vfs_extattrctl = vfs_stdextattrctl, 299 .vfs_suspendctl = layerfs_suspendctl, 300 .vfs_renamelock_enter = layerfs_renamelock_enter, 301 .vfs_renamelock_exit = layerfs_renamelock_exit, 302 .vfs_fsync = (void *)eopnotsupp, 303 .vfs_opv_descs = umapfs_vnodeopv_descs 304 }; 305 306 SYSCTL_SETUP(umapfs_sysctl_setup, "umapfs sysctl") 307 { 308 309 sysctl_createv(clog, 0, NULL, NULL, 310 CTLFLAG_PERMANENT, 311 CTLTYPE_NODE, "umap", 312 SYSCTL_DESCR("UID/GID remapping file system"), 313 NULL, 0, NULL, 0, 314 CTL_VFS, 10, CTL_EOL); 315 /* 316 * XXX the "10" above could be dynamic, thereby eliminating 317 * one more instance of the "number to vfs" mapping problem, 318 * but "10" is the order as taken from sys/mount.h 319 */ 320 } 321 322 static int 323 umap_modcmd(modcmd_t cmd, void *arg) 324 { 325 int error; 326 327 switch (cmd) { 328 case MODULE_CMD_INIT: 329 error = vfs_attach(&umapfs_vfsops); 330 if (error != 0) 331 break; 332 break; 333 case MODULE_CMD_FINI: 334 error = vfs_detach(&umapfs_vfsops); 335 if (error != 0) 336 break; 337 break; 338 default: 339 error = ENOTTY; 340 break; 341 } 342 343 return (error); 344 } 345
Indexes created Tue Oct 07 21:09:53 GMT 2025