xref: /freebsd/lib/libufs/type.c (revision a521f2116473fbd8c09db395518f060a27d02334)
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 	disk->d_fd = -1;
64 	if (disk->d_inoblock != NULL) {
65 		free(disk->d_inoblock);
66 		disk->d_inoblock = NULL;
67 	}
68 	if (disk->d_mine & MINE_NAME) {
69 		free((char *)(uintptr_t)disk->d_name);
70 		disk->d_name = NULL;
71 	}
72 	if (disk->d_si != NULL) {
73 		free(disk->d_si->si_csp);
74 		free(disk->d_si);
75 		disk->d_si = NULL;
76 	}
77 	return (0);
78 }
79 
80 int
81 ufs_disk_fillout(struct uufsd *disk, const char *name)
82 {
83 	if (ufs_disk_fillout_blank(disk, name) == -1) {
84 		return (-1);
85 	}
86 	if (sbread(disk) == -1) {
87 		ERROR(disk, "could not read superblock to fill out disk");
88 		ufs_disk_close(disk);
89 		return (-1);
90 	}
91 	return (0);
92 }
93 
94 int
95 ufs_disk_fillout_blank(struct uufsd *disk, const char *name)
96 {
97 	struct stat st;
98 	struct fstab *fs;
99 	struct statfs sfs;
100 	const char *oname;
101 	char dev[MAXPATHLEN];
102 	int fd, ret;
103 
104 	ERROR(disk, NULL);
105 
106 	oname = name;
107 again:	if ((ret = stat(name, &st)) < 0) {
108 		if (*name != '/') {
109 			snprintf(dev, sizeof(dev), "%s%s", _PATH_DEV, name);
110 			name = dev;
111 			goto again;
112 		}
113 		/*
114 		 * The given object doesn't exist, but don't panic just yet -
115 		 * it may be still mount point listed in /etc/fstab, but without
116 		 * existing corresponding directory.
117 		 */
118 		name = oname;
119 	}
120 	if (ret >= 0 && S_ISREG(st.st_mode)) {
121 		/* Possibly a disk image, give it a try.  */
122 		;
123 	} else if (ret >= 0 && S_ISCHR(st.st_mode)) {
124 		/* This is what we need, do nothing. */
125 		;
126 	} else if ((fs = getfsfile(name)) != NULL) {
127 		/*
128 		 * The given mount point is listed in /etc/fstab.
129 		 * It is possible that someone unmounted file system by hand
130 		 * and different file system is mounted on this mount point,
131 		 * but we still prefer /etc/fstab entry, because on the other
132 		 * hand, there could be /etc/fstab entry for this mount
133 		 * point, but file system is not mounted yet (eg. noauto) and
134 		 * statfs(2) will point us at different file system.
135 		 */
136 		name = fs->fs_spec;
137 	} else if (ret >= 0 && S_ISDIR(st.st_mode)) {
138 		/*
139 		 * The mount point is not listed in /etc/fstab, so it may be
140 		 * file system mounted by hand.
141 		 */
142 		if (statfs(name, &sfs) < 0) {
143 			ERROR(disk, "could not find special device");
144 			return (-1);
145 		}
146 		strlcpy(dev, sfs.f_mntfromname, sizeof(dev));
147 		name = dev;
148 	} else {
149 		ERROR(disk, "could not find special device");
150 		return (-1);
151 	}
152 	fd = open(name, O_RDONLY);
153 	if (fd == -1) {
154 		ERROR(disk, "could not open special device");
155 		return (-1);
156 	}
157 
158 	disk->d_bsize = 1;
159 	disk->d_ccg = 0;
160 	disk->d_fd = fd;
161 	disk->d_inoblock = NULL;
162 	disk->d_inomin = 0;
163 	disk->d_inomax = 0;
164 	disk->d_lcg = 0;
165 	disk->d_mine = 0;
166 	disk->d_ufs = 0;
167 	disk->d_error = NULL;
168 	disk->d_si = NULL;
169 
170 	if (oname != name) {
171 		name = strdup(name);
172 		if (name == NULL) {
173 			ERROR(disk, "could not allocate memory for disk name");
174 			return (-1);
175 		}
176 		disk->d_mine |= MINE_NAME;
177 	}
178 	disk->d_name = name;
179 
180 	return (0);
181 }
182 
183 int
184 ufs_disk_write(struct uufsd *disk)
185 {
186 	int fd;
187 
188 	ERROR(disk, NULL);
189 
190 	if (disk->d_mine & MINE_WRITE)
191 		return (0);
192 
193 	fd = open(disk->d_name, O_RDWR);
194 	if (fd < 0) {
195 		ERROR(disk, "failed to open disk for writing");
196 		return (-1);
197 	}
198 
199 	close(disk->d_fd);
200 	disk->d_fd = fd;
201 	disk->d_mine |= MINE_WRITE;
202 
203 	return (0);
204 }
205