geom_vol_ffs.c revision 332640 
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: stable/11/sys/geom/geom_vol_ffs.c 332640 2018-04-17 02:18:04Z kevans $");
29
30#include <sys/param.h>
31#include <sys/errno.h>
32#include <sys/systm.h>
33#include <sys/sysctl.h>
34#include <sys/kernel.h>
35#include <sys/malloc.h>
36#include <sys/bio.h>
37#include <sys/lock.h>
38#include <sys/mutex.h>
39
40#include <ufs/ufs/dinode.h>
41#include <ufs/ffs/fs.h>
42
43#include <geom/geom.h>
44#include <geom/geom_slice.h>
45
46FEATURE(geom_vol, "GEOM support for volume names from UFS superblock");
47
48#define VOL_FFS_CLASS_NAME "VOL_FFS"
49
50static int superblocks[] = SBLOCKSEARCH;
51static int g_vol_ffs_once;
52
53struct g_vol_ffs_softc {
54	char *	vol;
55};
56
57static int
58g_vol_ffs_start(struct bio *bp __unused)
59{
60	return(0);
61}
62
63static struct g_geom *
64g_vol_ffs_taste(struct g_class *mp, struct g_provider *pp, int flags)
65{
66	struct g_geom *gp;
67	struct g_consumer *cp;
68	struct g_vol_ffs_softc *ms;
69	int sb, superblock;
70	struct fs *fs;
71
72	g_trace(G_T_TOPOLOGY, "vol_taste(%s,%s)", mp->name, pp->name);
73	g_topology_assert();
74
75	/*
76	 * XXX This is a really weak way to make sure we don't recurse.
77	 * Probably ought to use BIO_GETATTR to check for this.
78	 */
79	if (flags == G_TF_NORMAL &&
80	    !strcmp(pp->geom->class->name, VOL_FFS_CLASS_NAME))
81		return (NULL);
82
83	gp = g_slice_new(mp, 1, pp, &cp, &ms, sizeof(*ms), g_vol_ffs_start);
84	if (gp == NULL)
85		return (NULL);
86	g_topology_unlock();
87	/*
88	 * Walk through the standard places that superblocks hide and look
89	 * for UFS magic. If we find magic, then check that the size in the
90	 * superblock corresponds to the size of the underlying provider.
91	 * Finally, look for a volume label and create an appropriate
92	 * provider based on that.
93	 */
94	for (sb=0; (superblock = superblocks[sb]) != -1; sb++) {
95		/*
96		 * Take care not to issue an invalid I/O request.  The
97		 * offset and size of the superblock candidate must be
98		 * multiples of the provider's sector size, otherwise an
99		 * FFS can't exist on the provider anyway.
100		 */
101		if (superblock % cp->provider->sectorsize != 0 ||
102		    SBLOCKSIZE % cp->provider->sectorsize != 0)
103			continue;
104
105		fs = (struct fs *) g_read_data(cp, superblock,
106			SBLOCKSIZE, NULL);
107		if (fs == NULL)
108			continue;
109		/* Check for magic and make sure things are the right size */
110		if (fs->fs_magic == FS_UFS1_MAGIC) {
111			if (fs->fs_old_size * fs->fs_fsize !=
112			    (int32_t) pp->mediasize) {
113				g_free(fs);
114				continue;
115			}
116		} else if (fs->fs_magic == FS_UFS2_MAGIC) {
117			if (fs->fs_size * fs->fs_fsize !=
118			    (int64_t) pp->mediasize) {
119				g_free(fs);
120				continue;
121			}
122		} else {
123			g_free(fs);
124			continue;
125		}
126		/* Check for volume label */
127		if (fs->fs_volname[0] == '\0') {
128			g_free(fs);
129			continue;
130		}
131		/* XXX We need to check for namespace conflicts. */
132		/* XXX How do you handle a mirror set? */
133		/* XXX We don't validate the volume name. */
134		g_topology_lock();
135		/* Alright, we have a label and a volume name, reconfig. */
136		g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t) 0,
137		    pp->mediasize, pp->sectorsize, "vol/%s",
138		    fs->fs_volname);
139		g_free(fs);
140		g_topology_unlock();
141		break;
142	}
143	g_topology_lock();
144	g_access(cp, -1, 0, 0);
145	if (LIST_EMPTY(&gp->provider)) {
146		g_slice_spoiled(cp);
147		return (NULL);
148	}
149	if (!g_vol_ffs_once) {
150		g_vol_ffs_once = 1;
151		printf(
152		    "WARNING: geom_vol_Ffs (geom %s) is deprecated, "
153		    "use glabel instead.\n", gp->name);
154	}
155	return (gp);
156}
157
158static struct g_class g_vol_ffs_class	= {
159	.name = VOL_FFS_CLASS_NAME,
160	.version = G_VERSION,
161	.taste = g_vol_ffs_taste,
162};
163
164DECLARE_GEOM_CLASS(g_vol_ffs_class, g_vol_ffs);
165MODULE_VERSION(geom_vol_ffs, 0);
166