freebsd-skq/sys/geom/label/g_label_ext2fs.c
sobomax e356b9f82b Some linux distros put mount point into the ext2fs labels, such as '/', or
'/boot', which confuses the devfs code and can cause userland programs to
fail reading /dev/ext2fs directory with weird error code, such as any
program that uses pwlib.

Strip any leading slashes before feeding the label to the geom_label code.

Sponsored by:	Sippy Software, Inc.

MFC after:	1 week
2011-03-08 17:00:31 +00:00

102 lines
2.8 KiB
C

/*-
* Copyright (c) 2005 Stanislav Sedov
* 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 AUTHOR 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 AUTHOR 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 <geom/geom.h>
#include <geom/label/g_label.h>
#define EXT2FS_SB_OFFSET 1024
#define EXT2_SUPER_MAGIC 0xef53
#define EXT2_DYNAMIC_REV 1
typedef struct e2sb {
uint8_t fake1[56];
uint16_t s_magic;
uint8_t fake2[18];
uint32_t s_rev_level;
uint8_t fake3[40];
char s_volume_name[16];
} e2sb_t;
static void
g_label_ext2fs_taste(struct g_consumer *cp, char *label, size_t size)
{
struct g_provider *pp;
e2sb_t *fs;
char *s_volume_name;
g_topology_assert_not();
pp = cp->provider;
label[0] = '\0';
if ((EXT2FS_SB_OFFSET % pp->sectorsize) != 0)
return;
fs = (e2sb_t *)g_read_data(cp, EXT2FS_SB_OFFSET, pp->sectorsize, NULL);
if (fs == NULL)
return;
/* Check for magic and versio n*/
if (fs->s_magic == EXT2_SUPER_MAGIC &&
fs->s_rev_level == EXT2_DYNAMIC_REV) {
G_LABEL_DEBUG(1, "ext2fs file system detected on %s.",
pp->name);
} else {
goto exit_free;
}
s_volume_name = fs->s_volume_name;
/* Terminate label */
s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
if (s_volume_name[0] == '/')
s_volume_name += 1;
/* Check for volume label */
if (s_volume_name[0] == '\0')
goto exit_free;
strlcpy(label, s_volume_name, size);
exit_free:
g_free(fs);
}
struct g_label_desc g_label_ext2fs = {
.ld_taste = g_label_ext2fs_taste,
.ld_dir = "ext2fs",
.ld_enabled = 1
};
G_LABEL_INIT(ext2fs, g_label_ext2fs, "Create device nodes for EXT2FS volumes");