xref: /freebsd/sys/geom/label/g_label_ufs.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1 /*-
2  * Copyright (c) 2002, 2003 Gordon Tetlow
3  * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions 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 AUTHORS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 
36 #include <ufs/ufs/dinode.h>
37 #include <ufs/ffs/fs.h>
38 
39 #include <geom/geom.h>
40 #include <geom/label/g_label.h>
41 
42 #define G_LABEL_UFS_DIR	"ufs"
43 
44 static const int superblocks[] = SBLOCKSEARCH;
45 
46 static void
47 g_label_ufs_taste(struct g_consumer *cp, char *label, size_t size)
48 {
49 	struct g_provider *pp;
50 	int sb, superblock;
51 	struct fs *fs;
52 
53 	g_topology_assert_not();
54 	pp = cp->provider;
55 	label[0] = '\0';
56 
57 	if (SBLOCKSIZE % cp->provider->sectorsize != 0)
58 		return;
59 
60 	/*
61 	 * Walk through the standard places that superblocks hide and look
62 	 * for UFS magic. If we find magic, then check that the size in the
63 	 * superblock corresponds to the size of the underlying provider.
64 	 * Finally, look for a volume label and create an appropriate
65 	 * provider based on that.
66 	 */
67 	for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
68 		/*
69 		 * Take care not to issue an invalid I/O request. The offset of
70 		 * the superblock candidate must be multiples of the provider's
71 		 * sector size, otherwise an FFS can't exist on the provider
72 		 * anyway.
73 		 */
74 		if (superblock % cp->provider->sectorsize != 0)
75 			continue;
76 
77 		fs = (struct fs *)g_read_data(cp, superblock, SBLOCKSIZE, NULL);
78 		if (fs == NULL)
79 			continue;
80 		/* Check for magic and make sure things are the right size */
81 		if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0 &&
82 		    pp->mediasize / fs->fs_fsize == fs->fs_old_size) {
83 		    	/* Valid UFS1. */
84 		} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0 &&
85 		    pp->mediasize / fs->fs_fsize == fs->fs_size) {
86 		    	/* Valid UFS2. */
87 		} else {
88 			g_free(fs);
89 			continue;
90 		}
91 		if (fs->fs_sblockloc != superblock || fs->fs_ncg < 1 ||
92 		    fs->fs_bsize < MINBSIZE ||
93 		    fs->fs_bsize < sizeof(struct fs)) {
94 			g_free(fs);
95 			continue;
96 		}
97 		G_LABEL_DEBUG(1, "%s file system detected on %s.",
98 		    fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
99 		/* Check for volume label */
100 		if (fs->fs_volname[0] == '\0') {
101 			g_free(fs);
102 			continue;
103 		}
104 		strlcpy(label, fs->fs_volname, size);
105 		g_free(fs);
106 		break;
107 	}
108 }
109 
110 const struct g_label_desc g_label_ufs = {
111 	.ld_taste = g_label_ufs_taste,
112 	.ld_dir = G_LABEL_UFS_DIR
113 };
114