xref: /freebsd/lib/libufs/type.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002 Juli Mallett.  All rights reserved.
5  *
6  * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
7  * FreeBSD project.  Redistribution and use in source and binary forms, with
8  * or without modification, are permitted provided that the following
9  * conditions are met:
10  *
11  * 1. Redistribution of source code must retain the above copyright notice,
12  *    this list of conditions and the following disclaimer.
13  * 2. Redistribution in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/mount.h>
35 #include <sys/disklabel.h>
36 #include <sys/stat.h>
37 
38 #include <ufs/ufs/ufsmount.h>
39 #include <ufs/ufs/dinode.h>
40 #include <ufs/ffs/fs.h>
41 
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <fstab.h>
45 #include <paths.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include <libufs.h>
52 
53 /* Internally, track the 'name' value, it's ours. */
54 #define	MINE_NAME	0x01
55 /* Track if its fd points to a writable device. */
56 #define	MINE_WRITE	0x02
57 
58 int
59 ufs_disk_close(struct uufsd *disk)
60 {
61 	ERROR(disk, NULL);
62 	close(disk->d_fd);
63 	if (disk->d_inoblock != NULL) {
64 		free(disk->d_inoblock);
65 		disk->d_inoblock = NULL;
66 	}
67 	if (disk->d_mine & MINE_NAME) {
68 		free((char *)(uintptr_t)disk->d_name);
69 		disk->d_name = NULL;
70 	}
71 	if (disk->d_sbcsum != NULL) {
72 		free(disk->d_sbcsum);
73 		disk->d_sbcsum = NULL;
74 	}
75 	return (0);
76 }
77 
78 int
79 ufs_disk_fillout(struct uufsd *disk, const char *name)
80 {
81 	if (ufs_disk_fillout_blank(disk, name) == -1) {
82 		return (-1);
83 	}
84 	if (sbread(disk) == -1) {
85 		ERROR(disk, "could not read superblock to fill out disk");
86 		ufs_disk_close(disk);
87 		return (-1);
88 	}
89 	return (0);
90 }
91 
92 int
93 ufs_disk_fillout_blank(struct uufsd *disk, const char *name)
94 {
95 	struct stat st;
96 	struct fstab *fs;
97 	struct statfs sfs;
98 	const char *oname;
99 	char dev[MAXPATHLEN];
100 	int fd, ret;
101 
102 	ERROR(disk, NULL);
103 
104 	oname = name;
105 again:	if ((ret = stat(name, &st)) < 0) {
106 		if (*name != '/') {
107 			snprintf(dev, sizeof(dev), "%s%s", _PATH_DEV, name);
108 			name = dev;
109 			goto again;
110 		}
111 		/*
112 		 * The given object doesn't exist, but don't panic just yet -
113 		 * it may be still mount point listed in /etc/fstab, but without
114 		 * existing corresponding directory.
115 		 */
116 		name = oname;
117 	}
118 	if (ret >= 0 && S_ISREG(st.st_mode)) {
119 		/* Possibly a disk image, give it a try.  */
120 		;
121 	} else if (ret >= 0 && S_ISCHR(st.st_mode)) {
122 		/* This is what we need, do nothing. */
123 		;
124 	} else if ((fs = getfsfile(name)) != NULL) {
125 		/*
126 		 * The given mount point is listed in /etc/fstab.
127 		 * It is possible that someone unmounted file system by hand
128 		 * and different file system is mounted on this mount point,
129 		 * but we still prefer /etc/fstab entry, because on the other
130 		 * hand, there could be /etc/fstab entry for this mount
131 		 * point, but file system is not mounted yet (eg. noauto) and
132 		 * statfs(2) will point us at different file system.
133 		 */
134 		name = fs->fs_spec;
135 	} else if (ret >= 0 && S_ISDIR(st.st_mode)) {
136 		/*
137 		 * The mount point is not listed in /etc/fstab, so it may be
138 		 * file system mounted by hand.
139 		 */
140 		if (statfs(name, &sfs) < 0) {
141 			ERROR(disk, "could not find special device");
142 			return (-1);
143 		}
144 		strlcpy(dev, sfs.f_mntfromname, sizeof(dev));
145 		name = dev;
146 	} else {
147 		ERROR(disk, "could not find special device");
148 		return (-1);
149 	}
150 	fd = open(name, O_RDONLY);
151 	if (fd == -1) {
152 		ERROR(disk, "could not open special device");
153 		return (-1);
154 	}
155 
156 	disk->d_bsize = 1;
157 	disk->d_ccg = 0;
158 	disk->d_fd = fd;
159 	disk->d_inoblock = NULL;
160 	disk->d_inomin = 0;
161 	disk->d_inomax = 0;
162 	disk->d_lcg = 0;
163 	disk->d_mine = 0;
164 	disk->d_ufs = 0;
165 	disk->d_error = NULL;
166 	disk->d_sbcsum = NULL;
167 
168 	if (oname != name) {
169 		name = strdup(name);
170 		if (name == NULL) {
171 			ERROR(disk, "could not allocate memory for disk name");
172 			return (-1);
173 		}
174 		disk->d_mine |= MINE_NAME;
175 	}
176 	disk->d_name = name;
177 
178 	return (0);
179 }
180 
181 int
182 ufs_disk_write(struct uufsd *disk)
183 {
184 	ERROR(disk, NULL);
185 
186 	if (disk->d_mine & MINE_WRITE)
187 		return (0);
188 
189 	close(disk->d_fd);
190 
191 	disk->d_fd = open(disk->d_name, O_RDWR);
192 	if (disk->d_fd < 0) {
193 		ERROR(disk, "failed to open disk for writing");
194 		return (-1);
195 	}
196 
197 	disk->d_mine |= MINE_WRITE;
198 
199 	return (0);
200 }
201