xref: /freebsd/sys/geom/label/g_label_ufs.c (revision 4b9d605768acabc460aa6dcfe8a1f8db35b16794)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
31 #include <sys/systm.h>
32 #include <sys/disklabel.h>
33 #include <sys/malloc.h>
34 #include <sys/vnode.h>
35 
36 #include <ufs/ufs/dinode.h>
37 #include <ufs/ffs/fs.h>
38 #include <ufs/ufs/quota.h>
39 #include <ufs/ufs/extattr.h>
40 #include <ufs/ffs/ffs_extern.h>
41 
42 #include <geom/geom.h>
43 #include <geom/geom_dbg.h>
44 #include <geom/label/g_label.h>
45 
46 #define	G_LABEL_UFS_VOLUME	0
47 #define	G_LABEL_UFS_ID		1
48 
49 /*
50  * G_LABEL_UFS_CMP returns true if difference between provider mediasize
51  * and filesystem size is less than G_LABEL_UFS_MAXDIFF sectors
52  */
53 #define	G_LABEL_UFS_CMP(prov, fsys, size) 				   \
54 	( abs( ((fsys)->size) - ( (prov)->mediasize / (fsys)->fs_fsize ))  \
55 				< G_LABEL_UFS_MAXDIFF )
56 #define	G_LABEL_UFS_MAXDIFF	0x100
57 
58 /*
59  * For providers that look like disklabels we need to check if the file system
60  * size is almost equal to the provider's size, because sysinstall(8) used to
61  * bogusly put the first partition at offset 0 instead of 16, and glabel/ufs
62  * would find a file system on the slice instead of the partition.
63  *
64  * In addition, media size can be a bit bigger than file system size. For
65  * instance, mkuzip can append bytes to align data to large sector size (it
66  * improves compression rates).
67  */
68 static bool
69 g_label_ufs_ignore_bsdlabel_slice(struct g_consumer *cp,
70     struct fs *fs)
71 {
72 	struct g_provider *pp;
73 	u_char *buf;
74 	uint32_t magic1, magic2;
75 	int error;
76 
77 	pp = cp->provider;
78 
79 	/*
80 	 * If the expected provider size for the filesystem matches the
81 	 * real provider size then don't ignore this filesystem.
82 	 */
83 	if (G_LABEL_UFS_CMP(pp, fs, fs_providersize))
84 		return (false);
85 
86 	/*
87 	 * If the filesystem size matches the real provider size then
88 	 * don't ignore this filesystem.
89 	 */
90 	if (fs->fs_magic == FS_UFS1_MAGIC ?
91 	    G_LABEL_UFS_CMP(pp, fs, fs_old_size) :
92 	    G_LABEL_UFS_CMP(pp, fs, fs_size))
93 		return (false);
94 
95 	/*
96 	 * Provider is bigger than expected; probe to see if there's a
97 	 * disklabel. Adapted from g_part_bsd_probe.
98 	 */
99 
100 	/* Check if the superblock overlaps where the disklabel lives. */
101 	if (fs->fs_sblockloc < pp->sectorsize * 2)
102 		return (false);
103 
104 	/* Sanity-check the provider. */
105 	if (pp->sectorsize < sizeof(struct disklabel) ||
106 	    pp->mediasize < BBSIZE)
107 		return (false);
108 	if (BBSIZE % pp->sectorsize)
109 		return (false);
110 
111 	/* Check that there's a disklabel. */
112 	buf = g_read_data(cp, pp->sectorsize, pp->sectorsize, &error);
113 	if (buf == NULL)
114 		return (false);
115 	magic1 = le32dec(buf + 0);
116 	magic2 = le32dec(buf + 132);
117 	g_free(buf);
118 	if (magic1 == DISKMAGIC && magic2 == DISKMAGIC)
119 		return (true);
120 
121 	return (false);
122 }
123 
124 /*
125  * Try to find a superblock on the provider. If successful, look for a volume
126  * label and create an appropriate provider based on that.
127  */
128 static void
129 g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int what)
130 {
131 	struct g_provider *pp;
132 	struct fs *fs;
133 
134 	g_topology_assert_not();
135 	pp = cp->provider;
136 	label[0] = '\0';
137 
138 	fs = NULL;
139 	KASSERT(pp->sectorsize != 0, ("Tasting a disk with 0 sectorsize"));
140 	if (SBLOCKSIZE % pp->sectorsize != 0 || ffs_sbget(cp, &fs, UFS_STDSB,
141 	    UFS_NOHASHFAIL | UFS_NOCSUM | UFS_NOMSG, M_GEOM, g_use_g_read_data)
142 	    != 0) {
143 		KASSERT(fs == NULL,
144 		    ("g_label_ufs_taste_common: non-NULL fs %p\n", fs));
145 		return;
146 	}
147 
148 	/* Check for magic. */
149 	if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0) {
150 		/* Valid UFS1. */
151 	} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0) {
152 		/* Valid UFS2. */
153 	} else {
154 		goto out;
155 	}
156 	/* Check if this should be ignored for compatibility. */
157 	if (g_label_ufs_ignore_bsdlabel_slice(cp, fs))
158 		goto out;
159 	G_LABEL_DEBUG(1, "%s file system detected on %s.",
160 	    fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
161 	switch (what) {
162 	case G_LABEL_UFS_VOLUME:
163 		/* Check for volume label */
164 		if (fs->fs_volname[0] != '\0')
165 			strlcpy(label, fs->fs_volname, size);
166 		break;
167 	case G_LABEL_UFS_ID:
168 		if (fs->fs_id[0] != 0 || fs->fs_id[1] != 0)
169 			snprintf(label, size, "%08x%08x", fs->fs_id[0],
170 			    fs->fs_id[1]);
171 		break;
172 	}
173 out:
174 	g_free(fs);
175 }
176 
177 static void
178 g_label_ufs_volume_taste(struct g_consumer *cp, char *label, size_t size)
179 {
180 
181 	g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_VOLUME);
182 }
183 
184 static void
185 g_label_ufs_id_taste(struct g_consumer *cp, char *label, size_t size)
186 {
187 
188 	g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_ID);
189 }
190 
191 struct g_label_desc g_label_ufs_volume = {
192 	.ld_taste = g_label_ufs_volume_taste,
193 	.ld_dirprefix = "ufs/",
194 	.ld_enabled = 1
195 };
196 
197 struct g_label_desc g_label_ufs_id = {
198 	.ld_taste = g_label_ufs_id_taste,
199 	.ld_dirprefix = "ufsid/",
200 	.ld_enabled = 1
201 };
202 
203 G_LABEL_INIT(ufsid, g_label_ufs_id, "Create device nodes for UFS file system IDs");
204 G_LABEL_INIT(ufs, g_label_ufs_volume, "Create device nodes for UFS volume names");
205 
206 MODULE_DEPEND(g_label, ufs, 1, 1, 1);
207