1 /* $NetBSD: umap_vfsops.c,v 1.105 2025/02/16 18:38:58 joe 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 1.105 2025/02/16 18:38:58 joe 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/syslog.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 /* 66 * Mount umap layer 67 */ 68 int 69 umapfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 70 { 71 struct lwp *l = curlwp; 72 struct pathbuf *pb; 73 struct nameidata nd; 74 struct umap_args *args = data; 75 struct vnode *lowerrootvp, *vp; 76 struct umap_mount *amp; 77 int error; 78 #ifdef UMAPFS_DIAGNOSTIC 79 int i; 80 #endif 81 fsid_t tfsid; 82 83 if (args == NULL) 84 return EINVAL; 85 if (*data_len < sizeof *args) { 86 #ifdef UMAPFS_DIAGNOSTIC 87 printf("mount_umap: data len %d < args %d\n", 88 (int)*data_len, (int)(sizeof *args)); 89 #endif 90 return EINVAL; 91 } 92 93 if (mp->mnt_flag & MNT_GETARGS) { 94 amp = MOUNTTOUMAPMOUNT(mp); 95 if (amp == NULL) 96 return EIO; 97 args->la.target = NULL; 98 args->nentries = amp->info_nentries; 99 args->gnentries = amp->info_gnentries; 100 *data_len = sizeof *args; 101 return 0; 102 } 103 104 /* only for root */ 105 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT, 106 KAUTH_REQ_SYSTEM_MOUNT_UMAP, NULL, NULL, NULL); 107 if (error) 108 return error; 109 110 #ifdef UMAPFS_DIAGNOSTIC 111 printf("umapfs_mount(mp = %p)\n", mp); 112 #endif 113 114 /* 115 * Update is not supported 116 */ 117 if (mp->mnt_flag & MNT_UPDATE) 118 return EOPNOTSUPP; 119 120 /* 121 * Find lower node 122 */ 123 error = pathbuf_copyin(args->umap_target, &pb); 124 if (error) { 125 return error; 126 } 127 NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb); 128 if ((error = namei(&nd)) != 0) { 129 pathbuf_destroy(pb); 130 return error; 131 } 132 133 /* 134 * Sanity check on lower vnode 135 */ 136 lowerrootvp = nd.ni_vp; 137 pathbuf_destroy(pb); 138 #ifdef UMAPFS_DIAGNOSTIC 139 printf("vp = %p, check for VDIR...\n", lowerrootvp); 140 #endif 141 142 if (lowerrootvp->v_type != VDIR) { 143 vput(lowerrootvp); 144 return (EINVAL); 145 } 146 147 #ifdef UMAPFS_DIAGNOSTIC 148 printf("mp = %p\n", mp); 149 #endif 150 151 amp = kmem_zalloc(sizeof(struct umap_mount), KM_SLEEP); 152 mp->mnt_data = amp; 153 154 /* 155 * Now copy in the number of entries and maps for umap mapping. 156 */ 157 if (args->nentries < 0 || args->nentries > MAPFILEENTRIES || 158 args->gnentries < 0 || args->gnentries > GMAPFILEENTRIES) { 159 vput(lowerrootvp); 160 return (EINVAL); 161 } 162 163 amp->info_nentries = args->nentries; 164 amp->info_gnentries = args->gnentries; 165 error = copyin(args->mapdata, amp->info_mapdata, 166 2*sizeof(u_long)*args->nentries); 167 if (error) { 168 vput(lowerrootvp); 169 return (error); 170 } 171 172 #ifdef UMAPFS_DIAGNOSTIC 173 printf("umap_mount:nentries %d\n",args->nentries); 174 for (i = 0; i < args->nentries; i++) 175 printf(" %ld maps to %ld\n", amp->info_mapdata[i][0], 176 amp->info_mapdata[i][1]); 177 #endif 178 179 error = copyin(args->gmapdata, amp->info_gmapdata, 180 2*sizeof(u_long)*args->gnentries); 181 if (error) { 182 vput(lowerrootvp); 183 return (error); 184 } 185 186 #ifdef UMAPFS_DIAGNOSTIC 187 printf("umap_mount:gnentries %d\n",args->gnentries); 188 for (i = 0; i < args->gnentries; i++) 189 printf("\tgroup %ld maps to %ld\n", 190 amp->info_gmapdata[i][0], 191 amp->info_gmapdata[i][1]); 192 #endif 193 194 /* 195 * Make sure the mount point's sufficiently initialized 196 * that the node create call will work. 197 */ 198 tfsid.__fsid_val[0] = (int32_t)args->fsid; 199 tfsid.__fsid_val[1] = makefstype(MOUNT_UMAP); 200 if (tfsid.__fsid_val[0] == 0) { 201 log(LOG_WARNING, "umapfs: fsid given as 0, ignoring\n"); 202 vfs_getnewfsid(mp); 203 } else if (vfs_getvfs(&tfsid)) { 204 log(LOG_WARNING, "umapfs: fsid %x already mounted\n", 205 tfsid.__fsid_val[0]); 206 vfs_getnewfsid(mp); 207 } else { 208 mp->mnt_stat.f_fsidx.__fsid_val[0] = tfsid.__fsid_val[0]; 209 mp->mnt_stat.f_fsidx.__fsid_val[1] = tfsid.__fsid_val[1]; 210 mp->mnt_stat.f_fsid = tfsid.__fsid_val[0]; 211 } 212 log(LOG_DEBUG, "umapfs: using fsid %x/%x\n", 213 mp->mnt_stat.f_fsidx.__fsid_val[0], 214 mp->mnt_stat.f_fsidx.__fsid_val[1]); 215 error = vfs_set_lowermount(mp, lowerrootvp->v_mount); 216 if (error) { 217 vput(lowerrootvp); 218 kmem_free(amp, sizeof(struct umap_mount)); 219 return error; 220 } 221 222 amp->umapm_size = sizeof(struct umap_node); 223 amp->umapm_tag = VT_UMAP; 224 amp->umapm_bypass = umap_bypass; 225 amp->umapm_vnodeop_p = umap_vnodeop_p; 226 227 /* 228 * fix up umap node for root vnode. 229 */ 230 VOP_UNLOCK(lowerrootvp); 231 error = layer_node_create(mp, lowerrootvp, &vp); 232 /* 233 * Make sure the node alias worked 234 */ 235 if (error) { 236 vrele(lowerrootvp); 237 kmem_free(amp, sizeof(struct umap_mount)); 238 return error; 239 } 240 241 /* 242 * Keep a held reference to the root vnode. 243 * It is vrele'd in umapfs_unmount. 244 */ 245 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 246 vp->v_vflag |= VV_ROOT; 247 amp->umapm_rootvp = vp; 248 VOP_UNLOCK(vp); 249 250 error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target, 251 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 252 if (error) 253 return error; 254 255 if (mp->mnt_lower->mnt_flag & MNT_LOCAL) 256 mp->mnt_flag |= MNT_LOCAL; 257 #ifdef UMAPFS_DIAGNOSTIC 258 printf("umapfs_mount: lower %s, alias at %s\n", 259 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 260 #endif 261 return 0; 262 } 263 264 /* 265 * Free reference to umap layer 266 */ 267 int 268 umapfs_unmount(struct mount *mp, int mntflags) 269 { 270 struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp); 271 struct vnode *rtvp = amp->umapm_rootvp; 272 int error; 273 int flags = 0; 274 275 #ifdef UMAPFS_DIAGNOSTIC 276 printf("umapfs_unmount(mp = %p)\n", mp); 277 #endif 278 279 if (mntflags & MNT_FORCE) 280 flags |= FORCECLOSE; 281 282 if (vrefcnt(rtvp) > 1 && (mntflags & MNT_FORCE) == 0) 283 return (EBUSY); 284 if ((error = vflush(mp, rtvp, flags)) != 0) 285 return (error); 286 287 #ifdef UMAPFS_DIAGNOSTIC 288 vprint("alias root of lower", rtvp); 289 #endif 290 /* 291 * Blow it away for future re-use 292 */ 293 vgone(rtvp); 294 /* 295 * Finally, throw away the umap_mount structure 296 */ 297 kmem_free(amp, sizeof(struct umap_mount)); 298 mp->mnt_data = NULL; 299 return 0; 300 } 301 302 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc; 303 304 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = { 305 &umapfs_vnodeop_opv_desc, 306 NULL, 307 }; 308 309 struct vfsops umapfs_vfsops = { 310 .vfs_name = MOUNT_UMAP, 311 .vfs_min_mount_data = sizeof (struct umap_args), 312 .vfs_mount = umapfs_mount, 313 .vfs_start = layerfs_start, 314 .vfs_unmount = umapfs_unmount, 315 .vfs_root = layerfs_root, 316 .vfs_quotactl = layerfs_quotactl, 317 .vfs_statvfs = layerfs_statvfs, 318 .vfs_sync = layerfs_sync, 319 .vfs_loadvnode = layerfs_loadvnode, 320 .vfs_vget = layerfs_vget, 321 .vfs_fhtovp = layerfs_fhtovp, 322 .vfs_vptofh = layerfs_vptofh, 323 .vfs_init = layerfs_init, 324 .vfs_done = layerfs_done, 325 .vfs_snapshot = layerfs_snapshot, 326 .vfs_extattrctl = vfs_stdextattrctl, 327 .vfs_suspendctl = layerfs_suspendctl, 328 .vfs_renamelock_enter = layerfs_renamelock_enter, 329 .vfs_renamelock_exit = layerfs_renamelock_exit, 330 .vfs_fsync = (void *)eopnotsupp, 331 .vfs_opv_descs = umapfs_vnodeopv_descs 332 }; 333 334 SYSCTL_SETUP(umapfs_sysctl_setup, "umapfs sysctl") 335 { 336 337 sysctl_createv(clog, 0, NULL, NULL, 338 CTLFLAG_PERMANENT, 339 CTLTYPE_NODE, "umap", 340 SYSCTL_DESCR("UID/GID remapping file system"), 341 NULL, 0, NULL, 0, 342 CTL_VFS, 10, CTL_EOL); 343 /* 344 * XXX the "10" above could be dynamic, thereby eliminating 345 * one more instance of the "number to vfs" mapping problem, 346 * but "10" is the order as taken from sys/mount.h 347 */ 348 } 349 350 static int 351 umap_modcmd(modcmd_t cmd, void *arg) 352 { 353 int error; 354 355 switch (cmd) { 356 case MODULE_CMD_INIT: 357 error = vfs_attach(&umapfs_vfsops); 358 break; 359 case MODULE_CMD_FINI: 360 error = vfs_detach(&umapfs_vfsops); 361 break; 362 default: 363 error = ENOTTY; 364 break; 365 } 366 367 return (error); 368 } 369
Indexes created Sat Sep 20 22:09:52 GMT 2025