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: releng/10.3/sys/geom/geom_vol_ffs.c 219029 2011-02-25 10:24:35Z netchild $");
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;
51
52struct g_vol_ffs_softc {
53	char *	vol;
54};
55
56static int
57g_vol_ffs_start(struct bio *bp __unused)
58{
59	return(0);
60}
61
62static struct g_geom *
63g_vol_ffs_taste(struct g_class *mp, struct g_provider *pp, int flags)
64{
65	struct g_geom *gp;
66	struct g_consumer *cp;
67	struct g_vol_ffs_softc *ms;
68	int sb, superblock;
69	struct fs *fs;
70
71	g_trace(G_T_TOPOLOGY, "vol_taste(%s,%s)", mp->name, pp->name);
72	g_topology_assert();
73
74	/*
75	 * XXX This is a really weak way to make sure we don't recurse.
76	 * Probably ought to use BIO_GETATTR to check for this.
77	 */
78	if (flags == G_TF_NORMAL &&
79	    !strcmp(pp->geom->class->name, VOL_FFS_CLASS_NAME))
80		return (NULL);
81
82	gp = g_slice_new(mp, 1, pp, &cp, &ms, sizeof(*ms), g_vol_ffs_start);
83	if (gp == NULL)
84		return (NULL);
85	g_topology_unlock();
86	/*
87	 * Walk through the standard places that superblocks hide and look
88	 * for UFS magic. If we find magic, then check that the size in the
89	 * superblock corresponds to the size of the underlying provider.
90	 * Finally, look for a volume label and create an appropriate
91	 * provider based on that.
92	 */
93	for (sb=0; (superblock = superblocks[sb]) != -1; sb++) {
94		/*
95		 * Take care not to issue an invalid I/O request.  The
96		 * offset and size of the superblock candidate must be
97		 * multiples of the provider's sector size, otherwise an
98		 * FFS can't exist on the provider anyway.
99		 */
100		if (superblock % cp->provider->sectorsize != 0 ||
101		    SBLOCKSIZE % cp->provider->sectorsize != 0)
102			continue;
103
104		fs = (struct fs *) g_read_data(cp, superblock,
105			SBLOCKSIZE, NULL);
106		if (fs == NULL)
107			continue;
108		/* Check for magic and make sure things are the right size */
109		if (fs->fs_magic == FS_UFS1_MAGIC) {
110			if (fs->fs_old_size * fs->fs_fsize !=
111			    (int32_t) pp->mediasize) {
112				g_free(fs);
113				continue;
114			}
115		} else if (fs->fs_magic == FS_UFS2_MAGIC) {
116			if (fs->fs_size * fs->fs_fsize !=
117			    (int64_t) pp->mediasize) {
118				g_free(fs);
119				continue;
120			}
121		} else {
122			g_free(fs);
123			continue;
124		}
125		/* Check for volume label */
126		if (fs->fs_volname[0] == '\0') {
127			g_free(fs);
128			continue;
129		}
130		/* XXX We need to check for namespace conflicts. */
131		/* XXX How do you handle a mirror set? */
132		/* XXX We don't validate the volume name. */
133		g_topology_lock();
134		/* Alright, we have a label and a volume name, reconfig. */
135		g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t) 0,
136		    pp->mediasize, pp->sectorsize, "vol/%s",
137		    fs->fs_volname);
138		g_free(fs);
139		g_topology_unlock();
140		break;
141	}
142	g_topology_lock();
143	g_access(cp, -1, 0, 0);
144	if (LIST_EMPTY(&gp->provider)) {
145		g_slice_spoiled(cp);
146		return (NULL);
147	}
148	return (gp);
149}
150
151static struct g_class g_vol_ffs_class	= {
152	.name = VOL_FFS_CLASS_NAME,
153	.version = G_VERSION,
154	.taste = g_vol_ffs_taste,
155};
156
157DECLARE_GEOM_CLASS(g_vol_ffs_class, g_vol_ffs);
158