xref: /freebsd/lib/libufs/type.c (revision a2b560cc69eb254c92caf2027a69cadf9865d273)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/param.h>
32 #include <sys/mount.h>
33 #include <sys/disklabel.h>
34 #include <sys/stat.h>
35 
36 #include <ufs/ufs/extattr.h>
37 #include <ufs/ufs/quota.h>
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_mine & MINE_NAME) {
65 		free((char *)(uintptr_t)disk->d_name);
66 		disk->d_name = NULL;
67 	}
68 	if (disk->d_si != NULL) {
69 		free(disk->d_si->si_csp);
70 		free(disk->d_si);
71 		disk->d_si = NULL;
72 	}
73 	return (0);
74 }
75 
76 int
77 ufs_disk_fillout(struct uufsd *disk, const char *name)
78 {
79 	if (ufs_disk_fillout_blank(disk, name) == -1) {
80 		return (-1);
81 	}
82 	if (sbread(disk) == -1) {
83 		ERROR(disk, "could not read superblock to fill out disk");
84 		ufs_disk_close(disk);
85 		return (-1);
86 	}
87 	return (0);
88 }
89 
90 int
91 ufs_disk_fillout_blank(struct uufsd *disk, const char *name)
92 {
93 	struct stat st;
94 	struct fstab *fs;
95 	struct statfs sfs;
96 	const char *oname;
97 	char dev[MAXPATHLEN];
98 	int fd, ret;
99 
100 	ERROR(disk, NULL);
101 
102 	oname = name;
103 again:	if ((ret = stat(name, &st)) < 0) {
104 		if (*name != '/') {
105 			snprintf(dev, sizeof(dev), "%s%s", _PATH_DEV, name);
106 			name = dev;
107 			goto again;
108 		}
109 		/*
110 		 * The given object doesn't exist, but don't panic just yet -
111 		 * it may be still mount point listed in /etc/fstab, but without
112 		 * existing corresponding directory.
113 		 */
114 		name = oname;
115 	}
116 	if (ret >= 0 && S_ISREG(st.st_mode)) {
117 		/* Possibly a disk image, give it a try.  */
118 		;
119 	} else if (ret >= 0 && S_ISCHR(st.st_mode)) {
120 		/* This is what we need, do nothing. */
121 		;
122 	} else if ((fs = getfsfile(name)) != NULL) {
123 		/*
124 		 * The given mount point is listed in /etc/fstab.
125 		 * It is possible that someone unmounted file system by hand
126 		 * and different file system is mounted on this mount point,
127 		 * but we still prefer /etc/fstab entry, because on the other
128 		 * hand, there could be /etc/fstab entry for this mount
129 		 * point, but file system is not mounted yet (eg. noauto) and
130 		 * statfs(2) will point us at different file system.
131 		 */
132 		name = fs->fs_spec;
133 	} else if (ret >= 0 && S_ISDIR(st.st_mode)) {
134 		/*
135 		 * The mount point is not listed in /etc/fstab, so it may be
136 		 * file system mounted by hand.
137 		 */
138 		if (statfs(name, &sfs) < 0) {
139 			ERROR(disk, "could not find special device");
140 			return (-1);
141 		}
142 		strlcpy(dev, sfs.f_mntfromname, sizeof(dev));
143 		name = dev;
144 	} else {
145 		ERROR(disk, "could not find special device");
146 		return (-1);
147 	}
148 	fd = open(name, O_RDONLY);
149 	if (fd == -1) {
150 		ERROR(disk, "could not open special device");
151 		return (-1);
152 	}
153 
154 	if (((uintptr_t)disk & ~(LIBUFS_BUFALIGN - 1)) != (uintptr_t)disk) {
155 		ERROR(disk, "uufsd structure must be aligned to "
156 		    "LIBUFS_BUFALIGN byte boundry, see ufs_disk_fillout(3)");
157 		close(fd);
158 		return (-1);
159 	}
160 
161 	disk->d_bsize = 1;
162 	disk->d_ccg = 0;
163 	disk->d_fd = fd;
164 	disk->d_inomin = 0;
165 	disk->d_inomax = 0;
166 	disk->d_lcg = 0;
167 	disk->d_mine = 0;
168 	disk->d_ufs = 0;
169 	disk->d_error = NULL;
170 	disk->d_si = NULL;
171 	disk->d_sblockloc = UFS_STDSB;
172 	disk->d_lookupflags = 0;
173 
174 	if (oname != name) {
175 		name = strdup(name);
176 		if (name == NULL) {
177 			ERROR(disk, "could not allocate memory for disk name");
178 			return (-1);
179 		}
180 		disk->d_mine |= MINE_NAME;
181 	}
182 	disk->d_name = name;
183 
184 	return (0);
185 }
186 
187 int
188 ufs_disk_write(struct uufsd *disk)
189 {
190 	int fd;
191 
192 	ERROR(disk, NULL);
193 
194 	if (disk->d_mine & MINE_WRITE)
195 		return (0);
196 
197 	fd = open(disk->d_name, O_RDWR);
198 	if (fd < 0) {
199 		ERROR(disk, "failed to open disk for writing");
200 		return (-1);
201 	}
202 
203 	close(disk->d_fd);
204 	disk->d_fd = fd;
205 	disk->d_mine |= MINE_WRITE;
206 
207 	return (0);
208 }
209