* csum.c --- checksumming of ext3 structures
*
* Copyright (C) 2006 Cluster File Systems, Inc.
+ * Copyright (C) 2006, 2007 by Andreas Dilger <adilger@clusterfs.com>
*
* %Begin-Header%
- * This file may be redistributed under the terms of the GNU Public
- * License.
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
* %End-Header%
*/
+#include "config.h"
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
#include "ext2_fs.h"
#include "ext2fs.h"
#include "crc16.h"
#define STATIC static
#endif
-STATIC __u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group)
+__u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group)
{
__u16 crc = 0;
struct ext2_group_desc *desc;
+ size_t size;
+
+ size = fs->super->s_desc_size;
+ if (size < EXT2_MIN_DESC_SIZE)
+ size = EXT2_MIN_DESC_SIZE;
+ if (size > sizeof(struct ext4_group_desc)) {
+ printf("%s: illegal s_desc_size(%zd)\n", __func__, size);
+ size = sizeof(struct ext4_group_desc);
+ }
- desc = &fs->group_desc[group];
+ desc = ext2fs_group_desc(fs, fs->group_desc, group);
if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
- int offset = offsetof(struct ext2_group_desc, bg_checksum);
+ size_t offset = offsetof(struct ext2_group_desc, bg_checksum);
#ifdef WORDS_BIGENDIAN
- struct ext2_group_desc swabdesc = *desc;
+ struct ext4_group_desc swabdesc;
/* Have to swab back to little-endian to do the checksum */
- ext2fs_swap_group_desc(&swabdesc);
- desc = &swabdesc;
+ memcpy(&swabdesc, desc, size);
+ ext2fs_swap_group_desc2(fs,
+ (struct ext2_group_desc *) &swabdesc);
+ desc = (struct ext2_group_desc *) &swabdesc;
group = ext2fs_swab32(group);
#endif
- crc = crc16(~0, fs->super->s_uuid, sizeof(fs->super->s_uuid));
- crc = crc16(crc, &group, sizeof(group));
- crc = crc16(crc, desc, offset);
+ crc = ext2fs_crc16(~0, fs->super->s_uuid,
+ sizeof(fs->super->s_uuid));
+ crc = ext2fs_crc16(crc, &group, sizeof(group));
+ crc = ext2fs_crc16(crc, desc, offset);
offset += sizeof(desc->bg_checksum); /* skip checksum */
- assert(offset == sizeof(*desc));
/* for checksum of struct ext4_group_desc do the rest...*/
- if (offset < fs->super->s_desc_size) {
- crc = crc16(crc, (char *)desc + offset,
- fs->super->s_desc_size - offset);
+ if (offset < size) {
+ crc = ext2fs_crc16(crc, (char *)desc + offset,
+ size - offset);
}
}
int ext2fs_group_desc_csum_verify(ext2_filsys fs, dgrp_t group)
{
- if (fs->group_desc[group].bg_checksum !=
- ext2fs_group_desc_csum(fs, group))
+ if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+ (ext2fs_bg_checksum(fs, group) !=
+ ext2fs_group_desc_csum(fs, group)))
return 0;
return 1;
void ext2fs_group_desc_csum_set(ext2_filsys fs, dgrp_t group)
{
- fs->group_desc[group].bg_checksum = ext2fs_group_desc_csum(fs, group);
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ return;
+
+ /* ext2fs_bg_checksum_set() sets the actual checksum field but
+ * does not calculate the checksum itself. */
+ ext2fs_bg_checksum_set(fs, group, ext2fs_group_desc_csum(fs, group));
}
static __u32 find_last_inode_ingrp(ext2fs_inode_bitmap bitmap,
end_ino = start_ino + inodes_per_grp - 1;
for (i = end_ino; i >= start_ino; i--) {
- if (ext2fs_fast_test_inode_bitmap(bitmap, i))
+ if (ext2fs_fast_test_inode_bitmap2(bitmap, i))
return i - start_ino + 1;
}
return inodes_per_grp;
errcode_t ext2fs_set_gdt_csum(ext2_filsys fs)
{
struct ext2_super_block *sb = fs->super;
- struct ext2_group_desc *bg = fs->group_desc;
- int blks, csum_flag, dirty = 0;
+ int dirty = 0;
dgrp_t i;
if (!fs->inode_map)
return EXT2_ET_NO_INODE_BITMAP;
- csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
- EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
- if (!EXT2_HAS_COMPAT_FEATURE(fs->super,
- EXT2_FEATURE_COMPAT_LAZY_BG) && !csum_flag)
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
return 0;
- for (i = 0; i < fs->group_desc_count; i++, bg++) {
- int old_csum = bg->bg_checksum;
- int old_unused = bg->bg_itable_unused;
- int old_flags = bg->bg_flags;
-
- if (bg->bg_free_inodes_count == sb->s_inodes_per_group &&
- i > 0 && (i < fs->group_desc_count - 1 || csum_flag)) {
- if (!(bg->bg_flags & EXT2_BG_INODE_UNINIT))
- bg->bg_flags |= EXT2_BG_INODE_UNINIT;
-
- if (csum_flag)
- bg->bg_itable_unused = sb->s_inodes_per_group;
- } else if (csum_flag) {
- bg->bg_flags &= ~EXT2_BG_INODE_UNINIT;
- bg->bg_itable_unused = sb->s_inodes_per_group -
+ for (i = 0; i < fs->group_desc_count; i++) {
+ __u32 old_csum = ext2fs_bg_checksum(fs, i);
+ __u32 old_unused = ext2fs_bg_itable_unused(fs, i);
+ __u32 old_flags = ext2fs_bg_flags(fs, i);
+ __u32 old_free_inodes_count = ext2fs_bg_free_inodes_count(fs, i);
+
+ if (old_free_inodes_count == sb->s_inodes_per_group) {
+ ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
+ ext2fs_bg_itable_unused_set(fs, i, sb->s_inodes_per_group);
+ } else {
+ int unused =
+ sb->s_inodes_per_group -
find_last_inode_ingrp(fs->inode_map,
- sb->s_inodes_per_group,i);
+ sb->s_inodes_per_group, i);
+
+ ext2fs_bg_flags_clear(fs, i, EXT2_BG_INODE_UNINIT);
+ ext2fs_bg_itable_unused_set(fs, i, unused);
}
- /* skip first and last groups, or groups with GDT backups
- * because the resize inode has blocks allocated in them. */
- if (i == 0 || i == fs->group_desc_count - 1 ||
- (ext2fs_bg_has_super(fs, i) && sb->s_reserved_gdt_blocks))
- goto checksum;
-
- blks = ext2fs_super_and_bgd_loc(fs, i, 0, 0, 0, 0);
- if (bg->bg_free_blocks_count == blks &&
- bg->bg_flags & EXT2_BG_INODE_UNINIT &&
- !(bg->bg_flags & EXT2_BG_BLOCK_UNINIT))
- bg->bg_flags |= EXT2_BG_BLOCK_UNINIT;
-checksum:
ext2fs_group_desc_csum_set(fs, i);
- if (old_flags != bg->bg_flags)
+ if (old_flags != ext2fs_bg_flags(fs, i))
dirty = 1;
- if (old_unused != bg->bg_itable_unused)
+ if (old_unused != ext2fs_bg_itable_unused(fs, i))
dirty = 1;
- if (old_csum != bg->bg_checksum)
+ if (old_csum != ext2fs_bg_checksum(fs, i))
dirty = 1;
}
if (dirty)
ext2fs_mark_super_dirty(fs);
return 0;
}
+
+#ifdef DEBUG
+#include "e2p/e2p.h"
+
+void print_csum(const char *msg, ext2_filsys fs, dgrp_t group)
+{
+ __u16 crc1, crc2, crc3;
+ dgrp_t swabgroup;
+ struct ext2_group_desc *desc = ext2fs_group_desc(fs, fs->group_desc, group);
+ size_t size;
+ struct ext2_super_block *sb = fs->super;
+ int offset = offsetof(struct ext2_group_desc, bg_checksum);
+#ifdef WORDS_BIGENDIAN
+ struct ext4_group_desc swabdesc;
+#endif
+
+ size = fs->super->s_desc_size;
+ if (size < EXT2_MIN_DESC_SIZE)
+ size = EXT2_MIN_DESC_SIZE;
+ if (size > sizeof(struct ext4_group_desc))
+ size = sizeof(struct ext4_group_desc);
+#ifdef WORDS_BIGENDIAN
+ /* Have to swab back to little-endian to do the checksum */
+ memcpy(&swabdesc, desc, size);
+ ext2fs_swap_group_desc2(fs, (struct ext2_group_desc *) &swabdesc);
+ desc = (struct ext2_group_desc *) &swabdesc;
+
+ swabgroup = ext2fs_swab32(group);
+#else
+ swabgroup = group;
+#endif
+
+ crc1 = ext2fs_crc16(~0, sb->s_uuid, sizeof(fs->super->s_uuid));
+ crc2 = ext2fs_crc16(crc1, &swabgroup, sizeof(swabgroup));
+ crc3 = ext2fs_crc16(crc2, desc, offset);
+ offset += sizeof(desc->bg_checksum); /* skip checksum */
+ /* for checksum of struct ext4_group_desc do the rest...*/
+ if (offset < size)
+ crc3 = ext2fs_crc16(crc3, (char *)desc + offset, size - offset);
+
+ printf("%s: UUID %s(%04x), grp %u(%04x): %04x=%04x\n",
+ msg, e2p_uuid2str(sb->s_uuid), crc1, group, crc2, crc3,
+ ext2fs_group_desc_csum(fs, group));
+}
+
+unsigned char sb_uuid[16] = { 0x4f, 0x25, 0xe8, 0xcf, 0xe7, 0x97, 0x48, 0x23,
+ 0xbe, 0xfa, 0xa7, 0x88, 0x4b, 0xae, 0xec, 0xdb };
+
+int main(int argc, char **argv)
+{
+ struct ext2_super_block param;
+ errcode_t retval;
+ ext2_filsys fs;
+ int i;
+ __u16 csum1, csum2, csum_known = 0xd3a4;
+
+ memset(¶m, 0, sizeof(param));
+ ext2fs_blocks_count_set(¶m, 32768);
+
+ retval = ext2fs_initialize("test fs", EXT2_FLAG_64BITS, ¶m,
+ test_io_manager, &fs);
+ if (retval) {
+ com_err("setup", retval,
+ "While initializing filesystem");
+ exit(1);
+ }
+ memcpy(fs->super->s_uuid, sb_uuid, 16);
+ fs->super->s_feature_ro_compat = EXT4_FEATURE_RO_COMPAT_GDT_CSUM;
+
+ for (i=0; i < fs->group_desc_count; i++) {
+ ext2fs_block_bitmap_loc_set(fs, i, 124);
+ ext2fs_inode_bitmap_loc_set(fs, i, 125);
+ ext2fs_inode_table_loc_set(fs, i, 126);
+ ext2fs_bg_free_blocks_count_set(fs, i, 31119);
+ ext2fs_bg_free_inodes_count_set(fs, i, 15701);
+ ext2fs_bg_used_dirs_count_set(fs, i, 2);
+ ext2fs_bg_flags_zap(fs, i);
+ };
+
+ csum1 = ext2fs_group_desc_csum(fs, 0);
+ print_csum("csum0000", fs, 0);
+
+ if (csum1 != csum_known) {
+ printf("checksum for group 0 should be %04x\n", csum_known);
+ exit(1);
+ }
+ csum2 = ext2fs_group_desc_csum(fs, 1);
+ print_csum("csum0001", fs, 1);
+ if (csum1 == csum2) {
+ printf("checksums for different groups shouldn't match\n");
+ exit(1);
+ }
+ csum2 = ext2fs_group_desc_csum(fs, 2);
+ print_csum("csumffff", fs, 2);
+ if (csum1 == csum2) {
+ printf("checksums for different groups shouldn't match\n");
+ exit(1);
+ }
+ ext2fs_bg_checksum_set(fs, 0, csum1);
+ csum2 = ext2fs_group_desc_csum(fs, 0);
+ print_csum("csum_set", fs, 0);
+ if (csum1 != csum2) {
+ printf("checksums should not depend on checksum field\n");
+ exit(1);
+ }
+ if (!ext2fs_group_desc_csum_verify(fs, 0)) {
+ printf("checksums should verify against gd_checksum\n");
+ exit(1);
+ }
+ memset(fs->super->s_uuid, 0x30, sizeof(fs->super->s_uuid));
+ print_csum("new_uuid", fs, 0);
+ if (ext2fs_group_desc_csum_verify(fs, 0) != 0) {
+ printf("checksums for different filesystems shouldn't match\n");
+ exit(1);
+ }
+ csum1 = ext2fs_group_desc_csum(fs, 0);
+ ext2fs_bg_checksum_set(fs, 0, csum1);
+ print_csum("csum_new", fs, 0);
+ ext2fs_bg_free_blocks_count_set(fs, 0, 1);
+ csum2 = ext2fs_group_desc_csum(fs, 0);
+ print_csum("csum_blk", fs, 0);
+ if (csum1 == csum2) {
+ printf("checksums for different data shouldn't match\n");
+ exit(1);
+ }
+
+ return 0;
+}
+#endif
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff