g_label_ufs.c revision 152971 
1/*-
2 * Copyright (c) 2002, 2003 Gordon Tetlow
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/geom/label/g_label_ufs.c 152971 2005-11-30 22:15:00Z sobomax $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/malloc.h>
34
35#include <ufs/ufs/dinode.h>
36#include <ufs/ffs/fs.h>
37
38#include <geom/geom.h>
39#include <geom/label/g_label.h>
40
41#define G_LABEL_UFS_DIR	"ufs"
42
43static const int superblocks[] = SBLOCKSEARCH;
44
45static void
46g_label_ufs_taste(struct g_consumer *cp, char *label, size_t size)
47{
48	struct g_provider *pp;
49	int sb, superblock;
50	struct fs *fs;
51
52	g_topology_assert_not();
53	pp = cp->provider;
54	label[0] = '\0';
55	/*
56	 * Walk through the standard places that superblocks hide and look
57	 * for UFS magic. If we find magic, then check that the size in the
58	 * superblock corresponds to the size of the underlying provider.
59	 * Finally, look for a volume label and create an appropriate
60	 * provider based on that.
61	 */
62	for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
63		/*
64		 * Take care not to issue an invalid I/O request.  The
65		 * offset and size of the superblock candidate must be
66		 * multiples of the provider's sector size, otherwise an
67		 * FFS can't exist on the provider anyway.
68		 */
69		if (superblock % cp->provider->sectorsize != 0 ||
70		    SBLOCKSIZE % cp->provider->sectorsize != 0)
71			continue;
72
73		fs = (struct fs *)g_read_data(cp, superblock, SBLOCKSIZE,
74		    NULL);
75		if (fs == NULL)
76			continue;
77		/* Check for magic and make sure things are the right size */
78		if (fs->fs_magic == FS_UFS1_MAGIC) {
79			G_LABEL_DEBUG(1, "UFS1 file system detected on %s.",
80			    pp->name);
81			if (fs->fs_old_size * fs->fs_fsize !=
82			    (int32_t)pp->mediasize) {
83				g_free(fs);
84				continue;
85			}
86		} else if (fs->fs_magic == FS_UFS2_MAGIC) {
87			G_LABEL_DEBUG(1, "UFS2 file system detected on %s.",
88			    pp->name);
89			if (fs->fs_fsize <= 0 ||
90			    pp->mediasize / fs->fs_fsize != fs->fs_size) {
91				g_free(fs);
92				continue;
93			}
94		} else {
95			g_free(fs);
96			continue;
97		}
98		/* Check for volume label */
99		if (fs->fs_volname[0] == '\0') {
100			g_free(fs);
101			continue;
102		}
103		strlcpy(label, fs->fs_volname, size);
104		g_free(fs);
105		break;
106	}
107}
108
109const struct g_label_desc g_label_ufs = {
110	.ld_taste = g_label_ufs_taste,
111	.ld_dir = G_LABEL_UFS_DIR
112};
113