xref: /freebsd/sys/geom/label/g_label_ufs.c (revision c7046f76c2c027b00c0e6ba57cfd28f1a78f5e23)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002, 2003 Gordon Tetlow
5  * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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 the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/disklabel.h>
36 #include <sys/malloc.h>
37 #include <sys/vnode.h>
38 
39 #include <ufs/ufs/dinode.h>
40 #include <ufs/ffs/fs.h>
41 #include <ufs/ufs/quota.h>
42 #include <ufs/ufs/extattr.h>
43 #include <ufs/ffs/ffs_extern.h>
44 
45 #include <geom/geom.h>
46 #include <geom/geom_dbg.h>
47 #include <geom/label/g_label.h>
48 
49 #define	G_LABEL_UFS_VOLUME	0
50 #define	G_LABEL_UFS_ID		1
51 
52 /*
53  * G_LABEL_UFS_CMP returns true if difference between provider mediasize
54  * and filesystem size is less than G_LABEL_UFS_MAXDIFF sectors
55  */
56 #define	G_LABEL_UFS_CMP(prov, fsys, size) 				   \
57 	( abs( ((fsys)->size) - ( (prov)->mediasize / (fsys)->fs_fsize ))  \
58 				< G_LABEL_UFS_MAXDIFF )
59 #define	G_LABEL_UFS_MAXDIFF	0x100
60 
61 /*
62  * For providers that look like disklabels we need to check if the file system
63  * size is almost equal to the provider's size, because sysinstall(8) used to
64  * bogusly put the first partition at offset 0 instead of 16, and glabel/ufs
65  * would find a file system on the slice instead of the partition.
66  *
67  * In addition, media size can be a bit bigger than file system size. For
68  * instance, mkuzip can append bytes to align data to large sector size (it
69  * improves compression rates).
70  */
71 static bool
72 g_label_ufs_ignore_bsdlabel_slice(struct g_consumer *cp,
73     struct fs *fs)
74 {
75 	struct g_provider *pp;
76 	u_char *buf;
77 	uint32_t magic1, magic2;
78 	int error;
79 
80 	pp = cp->provider;
81 
82 	/*
83 	 * If the expected provider size for the filesystem matches the
84 	 * real provider size then don't ignore this filesystem.
85 	 */
86 	if (G_LABEL_UFS_CMP(pp, fs, fs_providersize))
87 		return (false);
88 
89 	/*
90 	 * If the filesystem size matches the real provider size then
91 	 * don't ignore this filesystem.
92 	 */
93 	if (fs->fs_magic == FS_UFS1_MAGIC ?
94 	    G_LABEL_UFS_CMP(pp, fs, fs_old_size) :
95 	    G_LABEL_UFS_CMP(pp, fs, fs_size))
96 		return (false);
97 
98 	/*
99 	 * Provider is bigger than expected; probe to see if there's a
100 	 * disklabel. Adapted from g_part_bsd_probe.
101 	 */
102 
103 	/* Check if the superblock overlaps where the disklabel lives. */
104 	if (fs->fs_sblockloc < pp->sectorsize * 2)
105 		return (false);
106 
107 	/* Sanity-check the provider. */
108 	if (pp->sectorsize < sizeof(struct disklabel) ||
109 	    pp->mediasize < BBSIZE)
110 		return (false);
111 	if (BBSIZE % pp->sectorsize)
112 		return (false);
113 
114 	/* Check that there's a disklabel. */
115 	buf = g_read_data(cp, pp->sectorsize, pp->sectorsize, &error);
116 	if (buf == NULL)
117 		return (false);
118 	magic1 = le32dec(buf + 0);
119 	magic2 = le32dec(buf + 132);
120 	g_free(buf);
121 	if (magic1 == DISKMAGIC && magic2 == DISKMAGIC)
122 		return (true);
123 
124 	return (false);
125 }
126 
127 /*
128  * Try to find a superblock on the provider. If successful, look for a volume
129  * label and create an appropriate provider based on that.
130  */
131 static void
132 g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int what)
133 {
134 	struct g_provider *pp;
135 	struct fs *fs;
136 
137 	g_topology_assert_not();
138 	pp = cp->provider;
139 	label[0] = '\0';
140 
141 	fs = NULL;
142 	if (SBLOCKSIZE % pp->sectorsize != 0 || ffs_sbget(cp, &fs, UFS_STDSB,
143 	    UFS_NOHASHFAIL | UFS_NOCSUM | UFS_NOMSG, M_GEOM, g_use_g_read_data)
144 	    != 0) {
145 		KASSERT(fs == NULL,
146 		    ("g_label_ufs_taste_common: non-NULL fs %p\n", fs));
147 		return;
148 	}
149 
150 	/* Check for magic. */
151 	if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0) {
152 		/* Valid UFS1. */
153 	} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0) {
154 		/* Valid UFS2. */
155 	} else {
156 		goto out;
157 	}
158 	/* Check if this should be ignored for compatibility. */
159 	if (g_label_ufs_ignore_bsdlabel_slice(cp, fs))
160 		goto out;
161 	G_LABEL_DEBUG(1, "%s file system detected on %s.",
162 	    fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
163 	switch (what) {
164 	case G_LABEL_UFS_VOLUME:
165 		/* Check for volume label */
166 		if (fs->fs_volname[0] != '\0')
167 			strlcpy(label, fs->fs_volname, size);
168 		break;
169 	case G_LABEL_UFS_ID:
170 		if (fs->fs_id[0] != 0 || fs->fs_id[1] != 0)
171 			snprintf(label, size, "%08x%08x", fs->fs_id[0],
172 			    fs->fs_id[1]);
173 		break;
174 	}
175 out:
176 	g_free(fs);
177 }
178 
179 static void
180 g_label_ufs_volume_taste(struct g_consumer *cp, char *label, size_t size)
181 {
182 
183 	g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_VOLUME);
184 }
185 
186 static void
187 g_label_ufs_id_taste(struct g_consumer *cp, char *label, size_t size)
188 {
189 
190 	g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_ID);
191 }
192 
193 struct g_label_desc g_label_ufs_volume = {
194 	.ld_taste = g_label_ufs_volume_taste,
195 	.ld_dirprefix = "ufs/",
196 	.ld_enabled = 1
197 };
198 
199 struct g_label_desc g_label_ufs_id = {
200 	.ld_taste = g_label_ufs_id_taste,
201 	.ld_dirprefix = "ufsid/",
202 	.ld_enabled = 1
203 };
204 
205 G_LABEL_INIT(ufsid, g_label_ufs_id, "Create device nodes for UFS file system IDs");
206 G_LABEL_INIT(ufs, g_label_ufs_volume, "Create device nodes for UFS volume names");
207 
208 MODULE_DEPEND(g_label, ufs, 1, 1, 1);
209