freebsd-skq/sys/geom/label/g_label_ufs.c
ivoras 5d32651d0f Create GEOM labels from UFS IDs, e.g. /dev/ufsid/49c97b1faa2adc43. UFS IDs
are always present and can be used to identify file systems (useful if
hardware devices move often).

Actually-by:	pjd
Approved by:	gnn (mentor)
2009-03-25 20:38:57 +00:00

150 lines
4.4 KiB
C

/*-
* Copyright (c) 2002, 2003 Gordon Tetlow
* Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include <geom/geom.h>
#include <geom/label/g_label.h>
#define G_LABEL_UFS_VOLUME_DIR "ufs"
#define G_LABEL_UFS_ID_DIR "ufsid"
#define G_LABEL_UFS_VOLUME 0
#define G_LABEL_UFS_ID 1
static const int superblocks[] = SBLOCKSEARCH;
static void
g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int what)
{
struct g_provider *pp;
int sb, superblock;
struct fs *fs;
g_topology_assert_not();
pp = cp->provider;
label[0] = '\0';
if (SBLOCKSIZE % cp->provider->sectorsize != 0)
return;
/*
* Walk through the standard places that superblocks hide and look
* for UFS magic. If we find magic, then check that the size in the
* superblock corresponds to the size of the underlying provider.
* Finally, look for a volume label and create an appropriate
* provider based on that.
*/
for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
/*
* Take care not to issue an invalid I/O request. The offset of
* the superblock candidate must be multiples of the provider's
* sector size, otherwise an FFS can't exist on the provider
* anyway.
*/
if (superblock % cp->provider->sectorsize != 0)
continue;
fs = (struct fs *)g_read_data(cp, superblock, SBLOCKSIZE, NULL);
if (fs == NULL)
continue;
/* Check for magic and make sure things are the right size */
if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0 &&
pp->mediasize / fs->fs_fsize == fs->fs_old_size) {
/* Valid UFS1. */
} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0 &&
pp->mediasize / fs->fs_fsize == fs->fs_size) {
/* Valid UFS2. */
} else {
g_free(fs);
continue;
}
if (fs->fs_sblockloc != superblock || fs->fs_ncg < 1 ||
fs->fs_bsize < MINBSIZE ||
fs->fs_bsize < sizeof(struct fs)) {
g_free(fs);
continue;
}
G_LABEL_DEBUG(1, "%s file system detected on %s.",
fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
switch (what) {
case G_LABEL_UFS_VOLUME:
/* Check for volume label */
if (fs->fs_volname[0] == '\0') {
g_free(fs);
continue;
}
strlcpy(label, fs->fs_volname, size);
break;
case G_LABEL_UFS_ID:
if (fs->fs_id[0] == 0 && fs->fs_id[1] == 0) {
g_free(fs);
continue;
}
snprintf(label, size, "%08x%08x", fs->fs_id[0],
fs->fs_id[1]);
break;
}
g_free(fs);
break;
}
}
static void
g_label_ufs_volume_taste(struct g_consumer *cp, char *label, size_t size)
{
g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_VOLUME);
}
static void
g_label_ufs_id_taste(struct g_consumer *cp, char *label, size_t size)
{
g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_ID);
}
const struct g_label_desc g_label_ufs_volume = {
.ld_taste = g_label_ufs_volume_taste,
.ld_dir = G_LABEL_UFS_VOLUME_DIR
};
const struct g_label_desc g_label_ufs_id = {
.ld_taste = g_label_ufs_id_taste,
.ld_dir = G_LABEL_UFS_ID_DIR
};