xref: /freebsd/lib/libufs/type.c (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
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_sbcsum != NULL) {
73 		free(disk->d_sbcsum);
74 		disk->d_sbcsum = NULL;
75 	}
76 	return (0);
77 }
78 
79 int
80 ufs_disk_fillout(struct uufsd *disk, const char *name)
81 {
82 	if (ufs_disk_fillout_blank(disk, name) == -1) {
83 		return (-1);
84 	}
85 	if (sbread(disk) == -1) {
86 		ERROR(disk, "could not read superblock to fill out disk");
87 		ufs_disk_close(disk);
88 		return (-1);
89 	}
90 	return (0);
91 }
92 
93 int
94 ufs_disk_fillout_blank(struct uufsd *disk, const char *name)
95 {
96 	struct stat st;
97 	struct fstab *fs;
98 	struct statfs sfs;
99 	const char *oname;
100 	char dev[MAXPATHLEN];
101 	int fd, ret;
102 
103 	ERROR(disk, NULL);
104 
105 	oname = name;
106 again:	if ((ret = stat(name, &st)) < 0) {
107 		if (*name != '/') {
108 			snprintf(dev, sizeof(dev), "%s%s", _PATH_DEV, name);
109 			name = dev;
110 			goto again;
111 		}
112 		/*
113 		 * The given object doesn't exist, but don't panic just yet -
114 		 * it may be still mount point listed in /etc/fstab, but without
115 		 * existing corresponding directory.
116 		 */
117 		name = oname;
118 	}
119 	if (ret >= 0 && S_ISREG(st.st_mode)) {
120 		/* Possibly a disk image, give it a try.  */
121 		;
122 	} else if (ret >= 0 && S_ISCHR(st.st_mode)) {
123 		/* This is what we need, do nothing. */
124 		;
125 	} else if ((fs = getfsfile(name)) != NULL) {
126 		/*
127 		 * The given mount point is listed in /etc/fstab.
128 		 * It is possible that someone unmounted file system by hand
129 		 * and different file system is mounted on this mount point,
130 		 * but we still prefer /etc/fstab entry, because on the other
131 		 * hand, there could be /etc/fstab entry for this mount
132 		 * point, but file system is not mounted yet (eg. noauto) and
133 		 * statfs(2) will point us at different file system.
134 		 */
135 		name = fs->fs_spec;
136 	} else if (ret >= 0 && S_ISDIR(st.st_mode)) {
137 		/*
138 		 * The mount point is not listed in /etc/fstab, so it may be
139 		 * file system mounted by hand.
140 		 */
141 		if (statfs(name, &sfs) < 0) {
142 			ERROR(disk, "could not find special device");
143 			return (-1);
144 		}
145 		strlcpy(dev, sfs.f_mntfromname, sizeof(dev));
146 		name = dev;
147 	} else {
148 		ERROR(disk, "could not find special device");
149 		return (-1);
150 	}
151 	fd = open(name, O_RDONLY);
152 	if (fd == -1) {
153 		ERROR(disk, "could not open special device");
154 		return (-1);
155 	}
156 
157 	disk->d_bsize = 1;
158 	disk->d_ccg = 0;
159 	disk->d_fd = fd;
160 	disk->d_inoblock = NULL;
161 	disk->d_inomin = 0;
162 	disk->d_inomax = 0;
163 	disk->d_lcg = 0;
164 	disk->d_mine = 0;
165 	disk->d_ufs = 0;
166 	disk->d_error = NULL;
167 	disk->d_sbcsum = NULL;
168 
169 	if (oname != name) {
170 		name = strdup(name);
171 		if (name == NULL) {
172 			ERROR(disk, "could not allocate memory for disk name");
173 			return (-1);
174 		}
175 		disk->d_mine |= MINE_NAME;
176 	}
177 	disk->d_name = name;
178 
179 	return (0);
180 }
181 
182 int
183 ufs_disk_write(struct uufsd *disk)
184 {
185 	int fd;
186 
187 	ERROR(disk, NULL);
188 
189 	if (disk->d_mine & MINE_WRITE)
190 		return (0);
191 
192 	fd = open(disk->d_name, O_RDWR);
193 	if (fd < 0) {
194 		ERROR(disk, "failed to open disk for writing");
195 		return (-1);
196 	}
197 
198 	close(disk->d_fd);
199 	disk->d_fd = fd;
200 	disk->d_mine |= MINE_WRITE;
201 
202 	return (0);
203 }
204