xref: /freebsd/lib/libufs/type.c (revision 9517e866259191fcd39434a97ad849a9b59b9b9f)
1 /*
2  * Copyright (c) 2002 Juli Mallett.  All rights reserved.
3  *
4  * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
5  * FreeBSD project.  Redistribution and use in source and binary forms, with
6  * or without modification, are permitted provided that the following
7  * conditions are met:
8  *
9  * 1. Redistribution of source code must retain the above copyright notice,
10  *    this list of conditions and the following disclaimer.
11  * 2. Redistribution in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/mount.h>
33 #include <sys/disklabel.h>
34 #include <sys/stat.h>
35 
36 #include <ufs/ufs/ufsmount.h>
37 #include <ufs/ufs/dinode.h>
38 #include <ufs/ffs/fs.h>
39 
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <fstab.h>
43 #include <paths.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #include <libufs.h>
50 
51 /* Internally, track the 'name' value, it's ours. */
52 #define	MINE_NAME	0x01
53 /* Track if its fd points to a writable device. */
54 #define	MINE_WRITE	0x02
55 
56 int
57 ufs_disk_close(struct uufsd *disk)
58 {
59 	ERROR(disk, NULL);
60 	close(disk->d_fd);
61 	if (disk->d_inoblock != NULL) {
62 		free(disk->d_inoblock);
63 		disk->d_inoblock = NULL;
64 	}
65 	if (disk->d_mine & MINE_NAME) {
66 		free((char *)(uintptr_t)disk->d_name);
67 		disk->d_name = NULL;
68 	}
69 	return (0);
70 }
71 
72 int
73 ufs_disk_fillout(struct uufsd *disk, const char *name)
74 {
75 	if (ufs_disk_fillout_blank(disk, name) == -1) {
76 		return (-1);
77 	}
78 	if (sbread(disk) == -1) {
79 		ERROR(disk, "could not read superblock to fill out disk");
80 		return (-1);
81 	}
82 	return (0);
83 }
84 
85 int
86 ufs_disk_fillout_blank(struct uufsd *disk, const char *name)
87 {
88 	struct stat st;
89 	struct fstab *fs;
90 	struct statfs sfs;
91 	const char *oname;
92 	char dev[MAXPATHLEN];
93 	int fd, ret;
94 
95 	ERROR(disk, NULL);
96 
97 	oname = name;
98 again:	if ((ret = stat(name, &st)) < 0) {
99 		if (*name != '/') {
100 			snprintf(dev, sizeof(dev), "%s%s", _PATH_DEV, name);
101 			name = dev;
102 			goto again;
103 		}
104 		/*
105 		 * The given object doesn't exist, but don't panic just yet -
106 		 * it may be still mount point listed in /etc/fstab, but without
107 		 * existing corresponding directory.
108 		 */
109 		name = oname;
110 	}
111 	if (ret >= 0 && S_ISREG(st.st_mode)) {
112 		/* Possibly a disk image, give it a try.  */
113 		;
114 	} else if (ret >= 0 && S_ISCHR(st.st_mode)) {
115 		/* This is what we need, do nothing. */
116 		;
117 	} else if ((fs = getfsfile(name)) != NULL) {
118 		/*
119 		 * The given mount point is listed in /etc/fstab.
120 		 * It is possible that someone unmounted file system by hand
121 		 * and different file system is mounted on this mount point,
122 		 * but we still prefer /etc/fstab entry, because on the other
123 		 * hand, there could be /etc/fstab entry for this mount
124 		 * point, but file system is not mounted yet (eg. noauto) and
125 		 * statfs(2) will point us at different file system.
126 		 */
127 		name = fs->fs_spec;
128 	} else if (ret >= 0 && S_ISDIR(st.st_mode)) {
129 		/*
130 		 * The mount point is not listed in /etc/fstab, so it may be
131 		 * file system mounted by hand.
132 		 */
133 		if (statfs(name, &sfs) < 0) {
134 			ERROR(disk, "could not find special device");
135 			return (-1);
136 		}
137 		strlcpy(dev, sfs.f_mntfromname, sizeof(dev));
138 		name = dev;
139 	} else {
140 		ERROR(disk, "could not find special device");
141 		return (-1);
142 	}
143 	fd = open(name, O_RDONLY);
144 	if (fd == -1) {
145 		ERROR(disk, "could not open special device");
146 		return (-1);
147 	}
148 
149 	disk->d_bsize = 1;
150 	disk->d_ccg = 0;
151 	disk->d_fd = fd;
152 	disk->d_inoblock = NULL;
153 	disk->d_inomin = 0;
154 	disk->d_inomax = 0;
155 	disk->d_lcg = 0;
156 	disk->d_mine = 0;
157 	disk->d_ufs = 0;
158 	disk->d_error = NULL;
159 
160 	if (oname != name) {
161 		name = strdup(name);
162 		if (name == NULL) {
163 			ERROR(disk, "could not allocate memory for disk name");
164 			return (-1);
165 		}
166 		disk->d_mine |= MINE_NAME;
167 	}
168 	disk->d_name = name;
169 
170 	return (0);
171 }
172 
173 int
174 ufs_disk_write(struct uufsd *disk)
175 {
176 	ERROR(disk, NULL);
177 
178 	if (disk->d_mine & MINE_WRITE)
179 		return (0);
180 
181 	close(disk->d_fd);
182 
183 	disk->d_fd = open(disk->d_name, O_RDWR);
184 	if (disk->d_fd < 0) {
185 		ERROR(disk, "failed to open disk for writing");
186 		return (-1);
187 	}
188 
189 	disk->d_mine |= MINE_WRITE;
190 
191 	return (0);
192 }
193