snapshot.c revision 1.2.2.3
1 1.2.2.3 tron /* $NetBSD: snapshot.c,v 1.2.2.3 2005/04/21 19:05:37 tron Exp $ */ 2 1.2.2.2 tron 3 1.2.2.2 tron /*- 4 1.2.2.3 tron * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 1.2.2.2 tron * All rights reserved. 6 1.2.2.2 tron * 7 1.2.2.2 tron * This code is derived from software contributed to The NetBSD Foundation 8 1.2.2.2 tron * by Juergen Hannken-Illjes. 9 1.2.2.2 tron * 10 1.2.2.2 tron * Redistribution and use in source and binary forms, with or without 11 1.2.2.2 tron * modification, are permitted provided that the following conditions 12 1.2.2.2 tron * are met: 13 1.2.2.2 tron * 1. Redistributions of source code must retain the above copyright 14 1.2.2.2 tron * notice, this list of conditions and the following disclaimer. 15 1.2.2.2 tron * 2. Redistributions in binary form must reproduce the above copyright 16 1.2.2.2 tron * notice, this list of conditions and the following disclaimer in the 17 1.2.2.2 tron * documentation and/or other materials provided with the distribution. 18 1.2.2.2 tron * 3. All advertising materials mentioning features or use of this software 19 1.2.2.2 tron * must display the following acknowledgement: 20 1.2.2.2 tron * This product includes software developed by the NetBSD 21 1.2.2.2 tron * Foundation, Inc. and its contributors. 22 1.2.2.2 tron * 4. Neither the name of The NetBSD Foundation nor the names of its 23 1.2.2.2 tron * contributors may be used to endorse or promote products derived 24 1.2.2.2 tron * from this software without specific prior written permission. 25 1.2.2.2 tron * 26 1.2.2.2 tron * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 1.2.2.2 tron * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 1.2.2.2 tron * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 1.2.2.2 tron * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 1.2.2.2 tron * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 1.2.2.2 tron * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 1.2.2.2 tron * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 1.2.2.2 tron * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 1.2.2.2 tron * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 1.2.2.2 tron * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 1.2.2.2 tron * POSSIBILITY OF SUCH DAMAGE. 37 1.2.2.2 tron */ 38 1.2.2.2 tron 39 1.2.2.2 tron #include <sys/param.h> 40 1.2.2.2 tron #include <sys/ioctl.h> 41 1.2.2.2 tron #include <sys/mount.h> 42 1.2.2.2 tron #include <sys/stat.h> 43 1.2.2.2 tron 44 1.2.2.2 tron #include <dev/fssvar.h> 45 1.2.2.2 tron 46 1.2.2.2 tron #include <errno.h> 47 1.2.2.2 tron #include <fcntl.h> 48 1.2.2.2 tron #include <stdio.h> 49 1.2.2.2 tron #include <stdlib.h> 50 1.2.2.2 tron #include <unistd.h> 51 1.2.2.2 tron 52 1.2.2.2 tron #include "snapshot.h" 53 1.2.2.2 tron 54 1.2.2.2 tron /* 55 1.2.2.2 tron * Create a snapshot of the file system currently mounted on the first argument 56 1.2.2.2 tron * using the second argument as backing store and return an open file 57 1.2.2.2 tron * descriptor for the snapshot. If the second argument is NULL, use the first 58 1.2.2.2 tron * as backing store. If the third argument is not NULL, it gets the time the 59 1.2.2.2 tron * snapshot was created. 60 1.2.2.2 tron */ 61 1.2.2.2 tron int 62 1.2.2.2 tron snap_open(char *mountpoint, char *backup, time_t *snap_date) 63 1.2.2.2 tron { 64 1.2.2.2 tron int i, fd, israw, fsinternal, dounlink, flags; 65 1.2.2.2 tron char path[MAXPATHLEN], fss_dev[14]; 66 1.2.2.2 tron dev_t mountdev; 67 1.2.2.2 tron struct fss_set fss; 68 1.2.2.2 tron struct fss_get fsg; 69 1.2.2.2 tron struct stat sb; 70 1.2.2.2 tron struct statvfs fsb; 71 1.2.2.2 tron 72 1.2.2.2 tron dounlink = 0; 73 1.2.2.2 tron fd = -1; 74 1.2.2.2 tron 75 1.2.2.2 tron fss.fss_mount = mountpoint; 76 1.2.2.2 tron fss.fss_bstore = backup ? backup : fss.fss_mount; 77 1.2.2.2 tron fss.fss_csize = 0; 78 1.2.2.2 tron 79 1.2.2.2 tron if (stat(fss.fss_mount, &sb) < 0) 80 1.2.2.2 tron goto fail; 81 1.2.2.2 tron mountdev = sb.st_dev; 82 1.2.2.2 tron 83 1.2.2.2 tron /* 84 1.2.2.2 tron * Prepare the backing store. `backup' is either a raw device, 85 1.2.2.2 tron * a file or a directory. If it is a file, it must not exist. 86 1.2.2.2 tron */ 87 1.2.2.2 tron israw = 0; 88 1.2.2.2 tron if (stat(fss.fss_bstore, &sb) == 0) { 89 1.2.2.2 tron if (S_ISDIR(sb.st_mode)) { 90 1.2.2.2 tron snprintf(path, sizeof(path), 91 1.2.2.2 tron "%s/XXXXXXXXXX", fss.fss_bstore); 92 1.2.2.2 tron fd = mkstemp(path); 93 1.2.2.2 tron fss.fss_bstore = path; 94 1.2.2.2 tron dounlink = 1; 95 1.2.2.2 tron } else if (S_ISCHR(sb.st_mode)) { 96 1.2.2.2 tron fd = open(fss.fss_bstore, O_RDWR); 97 1.2.2.2 tron israw = 1; 98 1.2.2.2 tron } else 99 1.2.2.2 tron goto fail; 100 1.2.2.2 tron } else { 101 1.2.2.2 tron fd = open(fss.fss_bstore, O_CREAT|O_EXCL|O_WRONLY, 0600); 102 1.2.2.2 tron dounlink = 1; 103 1.2.2.2 tron } 104 1.2.2.2 tron if (fd < 0) 105 1.2.2.2 tron goto fail; 106 1.2.2.2 tron 107 1.2.2.2 tron if (fstat(fd, &sb) < 0) 108 1.2.2.2 tron goto fail; 109 1.2.2.2 tron fsinternal = (!israw && sb.st_dev == mountdev); 110 1.2.2.2 tron 111 1.2.2.2 tron /* 112 1.2.2.2 tron * If the backing store is a plain file and the snapshot 113 1.2.2.2 tron * is not file system internal, truncate to file system 114 1.2.2.2 tron * free space. 115 1.2.2.2 tron */ 116 1.2.2.2 tron if (!israw && !fsinternal) { 117 1.2.2.2 tron if (statvfs(fss.fss_bstore, &fsb) < 0) 118 1.2.2.2 tron goto fail; 119 1.2.2.2 tron if (ftruncate(fd, (off_t)fsb.f_frsize*fsb.f_bavail) < 0) 120 1.2.2.2 tron goto fail; 121 1.2.2.2 tron } 122 1.2.2.2 tron 123 1.2.2.2 tron if (close(fd) < 0) 124 1.2.2.2 tron goto fail; 125 1.2.2.2 tron 126 1.2.2.2 tron /* 127 1.2.2.2 tron * Create the snapshot on the first free snapshot device. 128 1.2.2.2 tron */ 129 1.2.2.2 tron for (i = 0; ; i++) { 130 1.2.2.2 tron snprintf(fss_dev, sizeof(fss_dev), "/dev/rfss%d", i); 131 1.2.2.2 tron if ((fd = open(fss_dev, O_RDWR, 0)) < 0) 132 1.2.2.2 tron goto fail; 133 1.2.2.2 tron 134 1.2.2.2 tron if (ioctl(fd, FSSIOFGET, &flags) < 0) 135 1.2.2.2 tron goto fail; 136 1.2.2.2 tron 137 1.2.2.2 tron if (ioctl(fd, FSSIOCSET, &fss) < 0) { 138 1.2.2.2 tron if (errno != EBUSY) 139 1.2.2.2 tron goto fail; 140 1.2.2.2 tron close(fd); 141 1.2.2.2 tron fd = -1; 142 1.2.2.2 tron continue; 143 1.2.2.2 tron } 144 1.2.2.2 tron 145 1.2.2.2 tron flags |= FSS_UNCONFIG_ON_CLOSE; 146 1.2.2.2 tron if (ioctl(fd, FSSIOCGET, &fsg) < 0 || 147 1.2.2.2 tron ioctl(fd, FSSIOFSET, &flags) < 0 || 148 1.2.2.2 tron (!israw && unlink(fss.fss_bstore) < 0)) { 149 1.2.2.2 tron ioctl(fd, FSSIOCCLR); 150 1.2.2.2 tron goto fail; 151 1.2.2.2 tron } 152 1.2.2.2 tron 153 1.2.2.2 tron if (snap_date != NULL) 154 1.2.2.2 tron *snap_date = fsg.fsg_time.tv_sec; 155 1.2.2.2 tron return fd; 156 1.2.2.2 tron } 157 1.2.2.2 tron 158 1.2.2.2 tron fail: 159 1.2.2.2 tron if (dounlink) 160 1.2.2.2 tron unlink(fss.fss_bstore); 161 1.2.2.2 tron if (fd >= 0) 162 1.2.2.2 tron close(fd); 163 1.2.2.2 tron 164 1.2.2.2 tron return -1; 165 1.2.2.2 tron } 166
Indexes created Tue Oct 14 00:09:49 GMT 2025