xref: /dragonfly/lib/libfsid/ext2.c (revision 8af44722)
1 /*
2  * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Ákos Kovács <akoskovacs@gmx.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <gnu/vfs/ext2fs/ext2_fs.h>
36 #include <gnu/vfs/ext2fs/fs.h>
37 
38 #include "libfsid.h"
39 
40 static char buffer[sizeof(struct ext2_super_block)*2];
41 
42 fsid_t
43 ext2_probe(const char *dev)
44 {
45 	static struct ext2_super_block *fs;
46 
47 	if (fsid_dev_read(dev, SBOFF, sizeof(buffer), buffer) != 0)
48 		return FSID_UNKNOWN;
49 
50 	fs = (struct ext2_super_block *)&buffer;
51 
52 	if (fs->s_magic == EXT2_SUPER_MAGIC)
53 		return FSID_EXT2;
54 
55 	return FSID_UNKNOWN;
56 }
57 
58 char *
59 ext2_volname(const char *dev)
60 {
61 	static struct ext2_super_block *fs;
62 
63 	if (fsid_dev_read(dev, SBOFF, sizeof(buffer), buffer) != 0)
64 		return NULL;
65 
66 	fs = (struct ext2_super_block *)&buffer;
67 
68 	if (fs->s_magic != EXT2_SUPER_MAGIC || fs->s_volume_name[0] == '\0')
69 		return NULL;
70 
71 	fs->s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
72 
73 	return fs->s_volume_name;
74 }
75