g_label_ext2fs.c revision 149395
1248484Sneel/*- 2248484Sneel * Copyright (c) 2005 Stanislav Sedov 3248484Sneel * All rights reserved. 4248484Sneel * 5248484Sneel * Redistribution and use in source and binary forms, with or without 6248484Sneel * modification, are permitted provided that the following conditions 7248484Sneel * are met: 8248484Sneel * 1. Redistributions of source code must retain the above copyright 9248484Sneel * notice, this list of conditions and the following disclaimer. 10248484Sneel * 2. Redistributions in binary form must reproduce the above copyright 11248484Sneel * notice, this list of conditions and the following disclaimer in the 12248484Sneel * documentation and/or other materials provided with the distribution. 13248484Sneel * 14248484Sneel * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15248484Sneel * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16248484Sneel * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17248484Sneel * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18248484Sneel * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19248484Sneel * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20248484Sneel * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21248484Sneel * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22248484Sneel * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23248484Sneel * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24248484Sneel * SUCH DAMAGE. 25248484Sneel */ 26248484Sneel 27248484Sneel#include <sys/cdefs.h> 28248484Sneel__FBSDID("$FreeBSD: head/sys/geom/label/g_label_ext2fs.c 149395 2005-08-23 18:55:38Z pjd $"); 29248484Sneel 30248484Sneel#include <sys/param.h> 31248484Sneel#include <sys/systm.h> 32248484Sneel#include <sys/kernel.h> 33248484Sneel#include <sys/malloc.h> 34256176Sneel 35248484Sneel#include <geom/geom.h> 36248484Sneel#include <geom/label/g_label.h> 37248484Sneel 38248484Sneel#define EXT2FS_SB_OFFSET 1024 39248484Sneel#define EXT2_SUPER_MAGIC 0xef53 40248484Sneel#define EXT2_DYNAMIC_REV 1 41248484Sneel 42248840Sneeltypedef struct e2sb { 43248484Sneel uint8_t fake1[56]; 44248484Sneel uint16_t s_magic; 45248484Sneel uint8_t fake2[18]; 46248484Sneel uint32_t s_rev_level; 47248840Sneel uint8_t fake3[40]; 48248484Sneel char s_volume_name[16]; 49248484Sneel} e2sb_t; 50256176Sneel 51248484Sneelstatic void 52248484Sneelg_label_ext2fs_taste(struct g_consumer *cp, char *label, size_t size) 53248484Sneel{ 54248484Sneel struct g_provider *pp; 55248484Sneel e2sb_t *fs; 56248484Sneel 57248484Sneel g_topology_assert_not(); 58248484Sneel pp = cp->provider; 59248484Sneel label[0] = '\0'; 60248484Sneel 61248484Sneel if ((EXT2FS_SB_OFFSET % pp->sectorsize) != 0) 62248484Sneel return; 63248484Sneel 64248484Sneel fs = (e2sb_t *)g_read_data(cp, EXT2FS_SB_OFFSET, pp->sectorsize, NULL); 65248484Sneel if (fs == NULL) 66248484Sneel return; 67248484Sneel 68248484Sneel /* Check for magic and versio n*/ 69248484Sneel if (fs->s_magic == EXT2_SUPER_MAGIC && 70248484Sneel fs->s_rev_level == EXT2_DYNAMIC_REV) { 71248484Sneel G_LABEL_DEBUG(1, "ext2fs file system detected on %s.", 72248484Sneel pp->name); 73248484Sneel } else { 74248484Sneel goto exit_free; 75248840Sneel } 76248484Sneel 77248840Sneel /* Check for volume label */ 78248484Sneel if (fs->s_volume_name[0] == '\0') 79248484Sneel goto exit_free; 80248484Sneel 81248484Sneel /* Terminate label */ 82248484Sneel fs->s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0'; 83248484Sneel strlcpy(label, fs->s_volume_name, size); 84248484Sneel 85248484Sneelexit_free: 86248484Sneel g_free(fs); 87248484Sneel} 88248840Sneel 89248840Sneelconst struct g_label_desc g_label_ext2fs = { 90248484Sneel .ld_taste = g_label_ext2fs_taste, 91248484Sneel .ld_dir = "ext2fs" 92248484Sneel}; 93248484Sneel