mount_unionfs.c revision 98266
11558Srgrimes/* 21558Srgrimes * Copyright (c) 1992, 1993, 1994 31558Srgrimes * The Regents of the University of California. All rights reserved. 41558Srgrimes * 51558Srgrimes * This code is derived from software donated to Berkeley by 61558Srgrimes * Jan-Simon Pendry. 71558Srgrimes * 81558Srgrimes * Redistribution and use in source and binary forms, with or without 91558Srgrimes * modification, are permitted provided that the following conditions 101558Srgrimes * are met: 111558Srgrimes * 1. Redistributions of source code must retain the above copyright 121558Srgrimes * notice, this list of conditions and the following disclaimer. 131558Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141558Srgrimes * notice, this list of conditions and the following disclaimer in the 151558Srgrimes * documentation and/or other materials provided with the distribution. 161558Srgrimes * 3. All advertising materials mentioning features or use of this software 171558Srgrimes * must display the following acknowledgement: 181558Srgrimes * This product includes software developed by the University of 191558Srgrimes * California, Berkeley and its contributors. 201558Srgrimes * 4. Neither the name of the University nor the names of its contributors 211558Srgrimes * may be used to endorse or promote products derived from this software 221558Srgrimes * without specific prior written permission. 231558Srgrimes * 241558Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251558Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261558Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271558Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281558Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291558Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301558Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311558Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321558Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331558Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341558Srgrimes * SUCH DAMAGE. 351558Srgrimes */ 361558Srgrimes 371558Srgrimes#ifndef lint 3828629Sstevestatic const char copyright[] = 391558Srgrimes"@(#) Copyright (c) 1992, 1993, 1994\n\ 401558Srgrimes The Regents of the University of California. All rights reserved.\n"; 411558Srgrimes#endif /* not lint */ 421558Srgrimes 431558Srgrimes#ifndef lint 4428629Ssteve#if 0 451558Srgrimesstatic char sccsid[] = "@(#)mount_union.c 8.5 (Berkeley) 3/27/94"; 4628629Ssteve#else 4728629Sstevestatic const char rcsid[] = 4850476Speter "$FreeBSD: head/sbin/mount_unionfs/mount_unionfs.c 98266 2002-06-15 22:48:14Z mux $"; 4928629Ssteve#endif 501558Srgrimes#endif /* not lint */ 511558Srgrimes 521558Srgrimes#include <sys/param.h> 531558Srgrimes#include <sys/mount.h> 541558Srgrimes 551558Srgrimes#include <err.h> 561558Srgrimes#include <stdio.h> 571558Srgrimes#include <stdlib.h> 581558Srgrimes#include <string.h> 5915770Swollman#include <sysexits.h> 601558Srgrimes#include <unistd.h> 611558Srgrimes 621558Srgrimes#include "mntopts.h" 631558Srgrimes 6415770Swollmanstatic struct mntopt mopts[] = { 651558Srgrimes MOPT_STDOPTS, 661558Srgrimes { NULL } 671558Srgrimes}; 681558Srgrimes 6992882Simpstatic int subdir(const char *, const char *); 7092882Simpstatic void usage (void) __dead2; 711558Srgrimes 721558Srgrimesint 731558Srgrimesmain(argc, argv) 741558Srgrimes int argc; 751558Srgrimes char *argv[]; 761558Srgrimes{ 7797196Smux struct iovec iov[8]; 7898266Smux int ch, mntflags; 7925275Sdfr char source[MAXPATHLEN]; 801558Srgrimes char target[MAXPATHLEN]; 8123680Speter struct vfsconf vfc; 8298266Smux int error, iovcnt; 831558Srgrimes 8498266Smux iovcnt = 6; 851558Srgrimes mntflags = 0; 8624359Simp while ((ch = getopt(argc, argv, "bo:r")) != -1) 871558Srgrimes switch (ch) { 881558Srgrimes case 'b': 8998266Smux iov[6].iov_base = "below"; 9098266Smux iov[6].iov_len = strlen(iov[6].iov_base) + 1; 9198266Smux iov[7].iov_base = NULL; 9298266Smux iov[7].iov_len = 0; 9398266Smux iovcnt = 8; 941558Srgrimes break; 951558Srgrimes case 'o': 964065Swollman getmntopts(optarg, mopts, &mntflags, 0); 971558Srgrimes break; 981558Srgrimes case 'r': 9998266Smux iov[6].iov_base = "replace"; 10098266Smux iov[6].iov_len = strlen(iov[6].iov_base) + 1; 10198266Smux iov[7].iov_base = NULL; 10298266Smux iov[7].iov_len = 0; 10398266Smux iovcnt = 8; 1041558Srgrimes break; 1051558Srgrimes case '?': 1061558Srgrimes default: 1071558Srgrimes usage(); 1081558Srgrimes /* NOTREACHED */ 1091558Srgrimes } 1101558Srgrimes argc -= optind; 1111558Srgrimes argv += optind; 1121558Srgrimes 1131558Srgrimes if (argc != 2) 1141558Srgrimes usage(); 1151558Srgrimes 11652055Sphk /* resolve both target and source with realpath(3) */ 11752055Sphk (void)checkpath(argv[0], target); 11852055Sphk (void)checkpath(argv[1], source); 1191558Srgrimes 12025275Sdfr if (subdir(target, source) || subdir(source, target)) 12125275Sdfr errx(EX_USAGE, "%s (%s) and %s (%s) are not distinct paths", 12225275Sdfr argv[0], target, argv[1], source); 12325275Sdfr 12477133Sru error = getvfsbyname("unionfs", &vfc); 12577133Sru if (error && vfsisloadable("unionfs")) { 12677133Sru if (vfsload("unionfs")) 12777133Sru err(EX_OSERR, "vfsload(unionfs)"); 1282999Swollman endvfsent(); /* flush cache */ 12977133Sru error = getvfsbyname("unionfs", &vfc); 1302999Swollman } 13123680Speter if (error) 13215770Swollman errx(EX_OSERR, "union filesystem is not available"); 1332999Swollman 13497196Smux iov[0].iov_base = "fstype"; 13598266Smux iov[0].iov_len = strlen(iov[0].iov_base) + 1; 13697196Smux iov[1].iov_base = vfc.vfc_name; 13797196Smux iov[1].iov_len = strlen(vfc.vfc_name) + 1; 13897196Smux iov[2].iov_base = "fspath"; 13998266Smux iov[2].iov_len = strlen(iov[2].iov_base) + 1; 14097196Smux iov[3].iov_base = source; 14197196Smux iov[3].iov_len = strlen(source) + 1; 14297196Smux iov[4].iov_base = "target"; 14398266Smux iov[4].iov_len = strlen(iov[4].iov_base) + 1; 14497196Smux iov[5].iov_base = target; 14597196Smux iov[5].iov_len = strlen(target) + 1; 14698266Smux if (nmount(iov, iovcnt, mntflags)) 14728629Ssteve err(EX_OSERR, "%s", target); 1481558Srgrimes exit(0); 1491558Srgrimes} 1501558Srgrimes 1511558Srgrimesint 1521558Srgrimessubdir(p, dir) 1531558Srgrimes const char *p; 1541558Srgrimes const char *dir; 1551558Srgrimes{ 1561558Srgrimes int l; 1571558Srgrimes 1581558Srgrimes l = strlen(dir); 1591558Srgrimes if (l <= 1) 1601558Srgrimes return (1); 1611558Srgrimes 1621558Srgrimes if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 1631558Srgrimes return (1); 1641558Srgrimes 1651558Srgrimes return (0); 1661558Srgrimes} 1671558Srgrimes 1681558Srgrimesvoid 1691558Srgrimesusage() 1701558Srgrimes{ 1711558Srgrimes (void)fprintf(stderr, 17277042Sru "usage: mount_unionfs [-br] [-o options] target_fs mount_point\n"); 17315770Swollman exit(EX_USAGE); 1741558Srgrimes} 175