xref: /freebsd/sys/geom/label/g_label_ufs.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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_VOLUME_DIR	"ufs"
43 #define G_LABEL_UFS_ID_DIR	"ufsid"
44 
45 #define	G_LABEL_UFS_VOLUME	0
46 #define	G_LABEL_UFS_ID		1
47 
48 /*
49  * G_LABEL_UFS_CMP returns true if difference between provider mediasize
50  * and filesystem size is less than G_LABEL_UFS_MAXDIFF sectors
51  */
52 #define	G_LABEL_UFS_CMP(prov, fsys, size) 				   \
53 	( abs( ((fsys)->size) - ( (prov)->mediasize / (fsys)->fs_fsize ))  \
54 				< G_LABEL_UFS_MAXDIFF )
55 #define	G_LABEL_UFS_MAXDIFF	0x100
56 
57 static const int superblocks[] = SBLOCKSEARCH;
58 
59 static void
60 g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int what)
61 {
62 	struct g_provider *pp;
63 	int sb, superblock;
64 	struct fs *fs;
65 
66 	g_topology_assert_not();
67 	pp = cp->provider;
68 	label[0] = '\0';
69 
70 	if (SBLOCKSIZE % cp->provider->sectorsize != 0)
71 		return;
72 
73 	/*
74 	 * Walk through the standard places that superblocks hide and look
75 	 * for UFS magic. If we find magic, then check that the size in the
76 	 * superblock corresponds to the size of the underlying provider.
77 	 * Finally, look for a volume label and create an appropriate
78 	 * provider based on that.
79 	 */
80 	for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
81 		/*
82 		 * Take care not to issue an invalid I/O request. The offset of
83 		 * the superblock candidate must be multiples of the provider's
84 		 * sector size, otherwise an FFS can't exist on the provider
85 		 * anyway.
86 		 */
87 		if (superblock % cp->provider->sectorsize != 0)
88 			continue;
89 
90 		fs = (struct fs *)g_read_data(cp, superblock, SBLOCKSIZE, NULL);
91 		if (fs == NULL)
92 			continue;
93 		/*
94 		 * Check for magic. We also need to check if file system size
95 		 * is almost equal to providers size, because sysinstall(8)
96 		 * used to bogusly put first partition at offset 0
97 		 * instead of 16, and glabel/ufs would find file system on slice
98 		 * instead of partition.
99 		 *
100 		 * In addition, media size can be a bit bigger than file system
101 		 * size. For instance, mkuzip can append bytes to align data
102 		 * to large sector size (it improves compression rates).
103 		 */
104 		switch (fs->fs_magic){
105 		case FS_UFS1_MAGIC:
106 		case FS_UFS2_MAGIC:
107 			G_LABEL_DEBUG(1, "%s %s params: %jd, %d, %d, %jd\n",
108 				fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2",
109 				pp->name, pp->mediasize, fs->fs_fsize,
110 				fs->fs_old_size, fs->fs_providersize);
111 			break;
112 		default:
113 			break;
114 		}
115 
116 		if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0 &&
117 		    ( G_LABEL_UFS_CMP(pp, fs, fs_old_size)
118 			|| G_LABEL_UFS_CMP(pp, fs, fs_providersize))) {
119 		    	/* Valid UFS1. */
120 		} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0 &&
121 		    ( G_LABEL_UFS_CMP(pp, fs, fs_size)
122 			|| G_LABEL_UFS_CMP(pp, fs, fs_providersize))) {
123 		    	/* Valid UFS2. */
124 		} else {
125 			g_free(fs);
126 			continue;
127 		}
128 		if (fs->fs_sblockloc != superblock || fs->fs_ncg < 1 ||
129 		    fs->fs_bsize < MINBSIZE ||
130 		    fs->fs_bsize < sizeof(struct fs)) {
131 			g_free(fs);
132 			continue;
133 		}
134 		G_LABEL_DEBUG(1, "%s file system detected on %s.",
135 		    fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
136 		switch (what) {
137 		case G_LABEL_UFS_VOLUME:
138 			/* Check for volume label */
139 			if (fs->fs_volname[0] == '\0') {
140 				g_free(fs);
141 				continue;
142 			}
143 			strlcpy(label, fs->fs_volname, size);
144 			break;
145 		case G_LABEL_UFS_ID:
146 			if (fs->fs_id[0] == 0 && fs->fs_id[1] == 0) {
147 				g_free(fs);
148 				continue;
149 			}
150 			snprintf(label, size, "%08x%08x", fs->fs_id[0],
151 			    fs->fs_id[1]);
152 			break;
153 		}
154 		g_free(fs);
155 		break;
156 	}
157 }
158 
159 static void
160 g_label_ufs_volume_taste(struct g_consumer *cp, char *label, size_t size)
161 {
162 
163 	g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_VOLUME);
164 }
165 
166 static void
167 g_label_ufs_id_taste(struct g_consumer *cp, char *label, size_t size)
168 {
169 
170 	g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_ID);
171 }
172 
173 struct g_label_desc g_label_ufs_volume = {
174 	.ld_taste = g_label_ufs_volume_taste,
175 	.ld_dir = G_LABEL_UFS_VOLUME_DIR,
176 	.ld_enabled = 1
177 };
178 
179 struct g_label_desc g_label_ufs_id = {
180 	.ld_taste = g_label_ufs_id_taste,
181 	.ld_dir = G_LABEL_UFS_ID_DIR,
182 	.ld_enabled = 1
183 };
184 
185 G_LABEL_INIT(ufsid, g_label_ufs_id, "Create device nodes for UFS file system IDs");
186 G_LABEL_INIT(ufs, g_label_ufs_volume, "Create device nodes for UFS volume names");
187