type.c revision 167625 
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: head/lib/libufs/type.c 167625 2007-03-16 03:13:28Z pjd $");
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
56int
57ufs_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
72int
73ufs_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
85int
86ufs_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;
98again:	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_ISCHR(st.st_mode)) {
112		/* This is what we need, do nothing. */
113		;
114	} else if ((fs = getfsfile(name)) != NULL) {
115		/*
116		 * The given mount point is listed in /etc/fstab.
117		 * It is possible that someone unmounted file system by hand
118		 * and different file system is mounted on this mount point,
119		 * but we still prefer /etc/fstab entry, because on the other
120		 * hand, there could be /etc/fstab entry for this mount
121		 * point, but file system is not mounted yet (eg. noauto) and
122		 * statfs(2) will point us at different file system.
123		 */
124		name = fs->fs_spec;
125	} else if (ret >= 0 && S_ISDIR(st.st_mode)) {
126		/*
127		 * The mount point is not listed in /etc/fstab, so it may be
128		 * file system mounted by hand.
129		 */
130		if (statfs(name, &sfs) < 0) {
131			ERROR(disk, "could not find special device");
132			return (-1);
133		}
134		strlcpy(dev, sfs.f_mntfromname, sizeof(dev));
135		name = dev;
136	} else {
137		ERROR(disk, "could not find special device");
138		return (-1);
139	}
140	fd = open(name, O_RDONLY);
141	if (fd == -1) {
142		ERROR(disk, "could not open special device");
143		return (-1);
144	}
145
146	disk->d_bsize = 1;
147	disk->d_ccg = 0;
148	disk->d_fd = fd;
149	disk->d_inoblock = NULL;
150	disk->d_inomin = 0;
151	disk->d_inomax = 0;
152	disk->d_lcg = 0;
153	disk->d_mine = 0;
154	disk->d_ufs = 0;
155	disk->d_error = NULL;
156
157	if (oname != name) {
158		name = strdup(name);
159		if (name == NULL) {
160			ERROR(disk, "could not allocate memory for disk name");
161			return (-1);
162		}
163		disk->d_mine |= MINE_NAME;
164	}
165	disk->d_name = name;
166
167	return (0);
168}
169
170int
171ufs_disk_write(struct uufsd *disk)
172{
173	ERROR(disk, NULL);
174
175	if (disk->d_mine & MINE_WRITE)
176		return (0);
177
178	close(disk->d_fd);
179
180	disk->d_fd = open(disk->d_name, O_RDWR);
181	if (disk->d_fd < 0) {
182		ERROR(disk, "failed to open disk for writing");
183		return (-1);
184	}
185
186	disk->d_mine |= MINE_WRITE;
187
188	return (0);
189}
190