geom_vol_ffs.c revision 113432 
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 * $FreeBSD: head/sys/geom/geom_vol_ffs.c 113432 2003-04-13 09:02:06Z phk $
27 */
28
29#include <sys/param.h>
30#include <sys/errno.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/malloc.h>
34#include <sys/bio.h>
35#include <sys/lock.h>
36#include <sys/mutex.h>
37
38#include <ufs/ufs/dinode.h>
39#include <ufs/ffs/fs.h>
40
41#include <geom/geom.h>
42#include <geom/geom_slice.h>
43
44#define VOL_FFS_CLASS_NAME "VOL_FFS"
45
46static int superblocks[] = SBLOCKSEARCH;
47
48struct g_vol_ffs_softc {
49	char *	vol;
50};
51
52static int
53g_vol_ffs_start(struct bio *bp __unused)
54{
55	return(0);
56}
57
58static struct g_geom *
59g_vol_ffs_taste(struct g_class *mp, struct g_provider *pp, int flags)
60{
61	struct g_geom *gp;
62	struct g_consumer *cp;
63	struct g_vol_ffs_softc *ms;
64	int error, sb, superblock;
65	struct fs *fs;
66
67	g_trace(G_T_TOPOLOGY, "vol_taste(%s,%s)", mp->name, pp->name);
68	g_topology_assert();
69
70	/*
71	 * XXX This is a really weak way to make sure we don't recurse.
72	 * Probably ought to use BIO_GETATTR to check for this.
73	 */
74	if (flags == G_TF_NORMAL &&
75	    !strcmp(pp->geom->class->name, VOL_FFS_CLASS_NAME))
76		return (NULL);
77
78	gp = g_slice_new(mp, 1, pp, &cp, &ms, sizeof(*ms), g_vol_ffs_start);
79	if (gp == NULL)
80		return (NULL);
81	g_topology_unlock();
82	/*
83	 * Walk through the standard places that superblocks hide and look
84	 * for UFS magic. If we find magic, then check that the size in the
85	 * superblock corresponds to the size of the underlying provider.
86	 * Finally, look for a volume label and create an appropriate
87	 * provider based on that.
88	 */
89	for (sb=0; (superblock = superblocks[sb]) != -1; sb++) {
90		fs = (struct fs *) g_read_data(cp, superblock,
91			SBLOCKSIZE, &error);
92		if (fs == NULL || error != 0)
93			continue;
94		/* Check for magic and make sure things are the right size */
95		if (fs->fs_magic == FS_UFS1_MAGIC) {
96			if (fs->fs_old_size * fs->fs_fsize !=
97			    (int32_t) pp->mediasize) {
98				g_free(fs);
99				continue;
100			}
101		} else if (fs->fs_magic == FS_UFS2_MAGIC) {
102			if (fs->fs_size * fs->fs_fsize !=
103			    (int64_t) pp->mediasize) {
104				g_free(fs);
105				continue;
106			}
107		} else {
108			g_free(fs);
109			continue;
110		}
111		/* Check for volume label */
112		if (fs->fs_volname[0] == '\0') {
113			g_free(fs);
114			continue;
115		}
116		/* XXX We need to check for namespace conflicts. */
117		/* XXX How do you handle a mirror set? */
118		/* XXX We don't validate the volume name. */
119		g_topology_lock();
120		/* Alright, we have a label and a volume name, reconfig. */
121		g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t) 0,
122		    pp->mediasize, pp->sectorsize, "vol/%s",
123		    fs->fs_volname);
124		g_free(fs);
125		g_topology_unlock();
126		break;
127	}
128	g_topology_lock();
129	g_access_rel(cp, -1, 0, 0);
130	if (LIST_EMPTY(&gp->provider)) {
131		g_std_spoiled(cp);
132		return (NULL);
133	}
134	return (gp);
135}
136
137static struct g_class g_vol_ffs_class	= {
138	.name = VOL_FFS_CLASS_NAME,
139	.taste = g_vol_ffs_taste,
140	G_CLASS_INITIALIZER
141};
142
143DECLARE_GEOM_CLASS(g_vol_ffs_class, g_vol_ffs);
144