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/*
* Copyright (C) 1999, 2001 by Andries Brouwer
* Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
* Copyright (C) 2008 Karel Zak <kzak@redhat.com>
*
* This file may be redistributed under the terms of the
* GNU Lesser General Public License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <stdint.h>
#ifdef __linux__
#include <sys/utsname.h>
#endif
#include <time.h>
#include "superblocks.h"
#include "crc32c.h"
struct ext2_super_block {
uint32_t s_inodes_count;
uint32_t s_blocks_count;
uint32_t s_r_blocks_count;
uint32_t s_free_blocks_count;
uint32_t s_free_inodes_count;
uint32_t s_first_data_block;
uint32_t s_log_block_size;
uint32_t s_dummy3[7];
unsigned char s_magic[2];
uint16_t s_state;
uint16_t s_errors;
uint16_t s_minor_rev_level;
uint32_t s_lastcheck;
uint32_t s_checkinterval;
uint32_t s_creator_os;
uint32_t s_rev_level;
uint16_t s_def_resuid;
uint16_t s_def_resgid;
uint32_t s_first_ino;
uint16_t s_inode_size;
uint16_t s_block_group_nr;
uint32_t s_feature_compat;
uint32_t s_feature_incompat;
uint32_t s_feature_ro_compat;
unsigned char s_uuid[16];
char s_volume_name[16];
char s_last_mounted[64];
uint32_t s_algorithm_usage_bitmap;
uint8_t s_prealloc_blocks;
uint8_t s_prealloc_dir_blocks;
uint16_t s_reserved_gdt_blocks;
uint8_t s_journal_uuid[16];
uint32_t s_journal_inum;
uint32_t s_journal_dev;
uint32_t s_last_orphan;
uint32_t s_hash_seed[4];
uint8_t s_def_hash_version;
uint8_t s_jnl_backup_type;
uint16_t s_reserved_word_pad;
uint32_t s_default_mount_opts;
uint32_t s_first_meta_bg;
uint32_t s_mkfs_time;
uint32_t s_jnl_blocks[17];
uint32_t s_blocks_count_hi;
uint32_t s_r_blocks_count_hi;
uint32_t s_free_blocks_hi;
uint16_t s_min_extra_isize;
uint16_t s_want_extra_isize;
uint32_t s_flags;
uint16_t s_raid_stride;
uint16_t s_mmp_interval;
uint64_t s_mmp_block;
uint32_t s_raid_stripe_width;
uint32_t s_reserved[162];
uint32_t s_checksum;
} __attribute__((packed));
/* magic string */
#define EXT_SB_MAGIC "\123\357"
/* supper block offset */
#define EXT_SB_OFF 0x400
/* supper block offset in kB */
#define EXT_SB_KBOFF (EXT_SB_OFF >> 10)
/* magic string offset within super block */
#define EXT_MAG_OFF 0x38
/* for s_flags */
#define EXT2_FLAGS_TEST_FILESYS 0x0004
/* for s_feature_compat */
#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
/* for s_feature_ro_compat */
#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400
/* for s_feature_incompat */
#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
#define EXT4_FEATURE_INCOMPAT_MMP 0x0100
#define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
#define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
#define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
EXT2_FEATURE_INCOMPAT_META_BG)
#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
#define EXT3_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
#define EXT3_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
EXT3_FEATURE_INCOMPAT_RECOVER| \
EXT2_FEATURE_INCOMPAT_META_BG)
#define EXT3_FEATURE_INCOMPAT_UNSUPPORTED ~EXT3_FEATURE_INCOMPAT_SUPP
#define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT3_FEATURE_RO_COMPAT_SUPP
/*
* Starting in 2.6.29, ext4 can be used to support filesystems
* without a journal.
*/
#define EXT4_SUPPORTS_EXT2 KERNEL_VERSION(2, 6, 29)
/*
* reads superblock and returns:
* fc = feature_compat
* fi = feature_incompat
* frc = feature_ro_compat
*/
static struct ext2_super_block *ext_get_super(
blkid_probe pr, uint32_t *fc, uint32_t *fi, uint32_t *frc)
{
struct ext2_super_block *es;
es = (struct ext2_super_block *)
blkid_probe_get_buffer(pr, EXT_SB_OFF, sizeof(struct ext2_super_block));
if (!es)
return NULL;
if (le32_to_cpu(es->s_feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) {
uint32_t csum = crc32c(~0, es, offsetof(struct ext2_super_block, s_checksum));
if (!blkid_probe_verify_csum(pr, csum, le32_to_cpu(es->s_checksum)))
return NULL;
}
if (fc)
*fc = le32_to_cpu(es->s_feature_compat);
if (fi)
*fi = le32_to_cpu(es->s_feature_incompat);
if (frc)
*frc = le32_to_cpu(es->s_feature_ro_compat);
return es;
}
static void ext_get_info(blkid_probe pr, int ver, struct ext2_super_block *es)
{
struct blkid_chain *chn = blkid_probe_get_chain(pr);
uint32_t s_feature_incompat = le32_to_cpu(es->s_feature_incompat);
DBG(PROBE, ul_debug("ext2_sb.compat = %08X:%08X:%08X",
le32_to_cpu(es->s_feature_compat),
s_feature_incompat,
le32_to_cpu(es->s_feature_ro_compat)));
if (*es->s_volume_name != '\0')
blkid_probe_set_label(pr, (unsigned char *) es->s_volume_name,
sizeof(es->s_volume_name));
blkid_probe_set_uuid(pr, es->s_uuid);
if (le32_to_cpu(es->s_feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
blkid_probe_set_uuid_as(pr, es->s_journal_uuid, "EXT_JOURNAL");
if (ver != 2 && (chn->flags & BLKID_SUBLKS_SECTYPE) &&
((s_feature_incompat & EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
blkid_probe_set_value(pr, "SEC_TYPE",
(unsigned char *) "ext2",
sizeof("ext2"));
blkid_probe_sprintf_version(pr, "%u.%u",
le32_to_cpu(es->s_rev_level),
le16_to_cpu(es->s_minor_rev_level));
uint32_t block_size = 0;
if (le32_to_cpu(es->s_log_block_size) < 32){
block_size = 1024U << le32_to_cpu(es->s_log_block_size);
blkid_probe_set_fsblocksize(pr, block_size);
blkid_probe_set_block_size(pr, block_size);
}
uint64_t fslastblock = le32_to_cpu(es->s_blocks_count) |
((s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) ?
(uint64_t) le32_to_cpu(es->s_blocks_count_hi) << 32 : 0);
blkid_probe_set_fslastblock(pr, fslastblock);
/* The total number of blocks is taken without substraction of overhead
* (journal, metadata). The ext4 has non-trivial overhead calculation
* viz. ext4_calculate_overhead(). Thefore, the FSSIZE would show number
* slightly higher than the real value (for example, calculated via
* statfs()).
*/
uint64_t fssize = (uint64_t) block_size * le32_to_cpu(es->s_blocks_count);
blkid_probe_set_fssize(pr, fssize);
}
static int probe_jbd(blkid_probe pr,
const struct blkid_idmag *mag __attribute__((__unused__)))
{
struct ext2_super_block *es;
uint32_t fi;
es = ext_get_super(pr, NULL, &fi, NULL);
if (!es)
return errno ? -errno : 1;
if (!(fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
return 1;
ext_get_info(pr, 2, es);
blkid_probe_set_uuid_as(pr, es->s_uuid, "LOGUUID");
return 0;
}
static int probe_ext2(blkid_probe pr,
const struct blkid_idmag *mag __attribute__((__unused__)))
{
struct ext2_super_block *es;
uint32_t fc, frc, fi;
es = ext_get_super(pr, &fc, &fi, &frc);
if (!es)
return errno ? -errno : 1;
/* Distinguish between ext3 and ext2 */
if (fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
return 1;
/* Any features which ext2 doesn't understand */
if ((frc & EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
(fi & EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
return 1;
ext_get_info(pr, 2, es);
return 0;
}
static int probe_ext3(blkid_probe pr,
const struct blkid_idmag *mag __attribute__((__unused__)))
{
struct ext2_super_block *es;
uint32_t fc, frc, fi;
es = ext_get_super(pr, &fc, &fi, &frc);
if (!es)
return errno ? -errno : 1;
/* ext3 requires journal */
if (!(fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
return 1;
/* Any features which ext3 doesn't understand */
if ((frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
(fi & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
return 1;
ext_get_info(pr, 3, es);
return 0;
}
static int probe_ext4dev(blkid_probe pr,
const struct blkid_idmag *mag __attribute__((__unused__)))
{
struct ext2_super_block *es;
uint32_t fc, frc, fi;
es = ext_get_super(pr, &fc, &fi, &frc);
if (!es)
return errno ? -errno : 1;
/* Distinguish from jbd */
if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
return 1;
if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS))
return 1;
ext_get_info(pr, 4, es);
return 0;
}
static int probe_ext4(blkid_probe pr,
const struct blkid_idmag *mag __attribute__((__unused__)))
{
struct ext2_super_block *es;
uint32_t fc, frc, fi;
es = ext_get_super(pr, &fc, &fi, &frc);
if (!es)
return errno ? -errno : 1;
/* Distinguish from jbd */
if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
return 1;
/* Ext4 has at least one feature which ext3 doesn't understand */
if (!(frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
!(fi & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
return 1;
/*
* If the filesystem is a OK for use by in-development
* filesystem code, and ext4dev is supported or ext4 is not
* supported, then don't call ourselves ext4, so we can redo
* the detection and mark the filesystem as ext4dev.
*
* If the filesystem is marked as in use by production
* filesystem, then it can only be used by ext4 and NOT by
* ext4dev.
*/
if (le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)
return 1;
ext_get_info(pr, 4, es);
return 0;
}
#define BLKID_EXT_MAGICS \
{ \
{ \
.magic = EXT_SB_MAGIC, \
.len = sizeof(EXT_SB_MAGIC) - 1, \
.kboff = EXT_SB_KBOFF, \
.sboff = EXT_MAG_OFF \
}, \
{ NULL } \
}
const struct blkid_idinfo jbd_idinfo =
{
.name = "jbd",
.usage = BLKID_USAGE_OTHER,
.probefunc = probe_jbd,
.magics = BLKID_EXT_MAGICS
};
const struct blkid_idinfo ext2_idinfo =
{
.name = "ext2",
.usage = BLKID_USAGE_FILESYSTEM,
.probefunc = probe_ext2,
.magics = BLKID_EXT_MAGICS
};
const struct blkid_idinfo ext3_idinfo =
{
.name = "ext3",
.usage = BLKID_USAGE_FILESYSTEM,
.probefunc = probe_ext3,
.magics = BLKID_EXT_MAGICS
};
const struct blkid_idinfo ext4_idinfo =
{
.name = "ext4",
.usage = BLKID_USAGE_FILESYSTEM,
.probefunc = probe_ext4,
.magics = BLKID_EXT_MAGICS
};
const struct blkid_idinfo ext4dev_idinfo =
{
.name = "ext4dev",
.usage = BLKID_USAGE_FILESYSTEM,
.probefunc = probe_ext4dev,
.magics = BLKID_EXT_MAGICS
};
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