* 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%
*/
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
#include "ext2_fs.h"
#include "ext2fs.h"
#include "crc16.h"
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,
+ crc = ext2fs_crc16(crc, (char *)desc + offset,
fs->super->s_desc_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) &&
+ (fs->group_desc[group].bg_checksum !=
+ 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))
+ fs->group_desc[group].bg_checksum =
+ ext2fs_group_desc_csum(fs, group);
}
static __u32 find_last_inode_ingrp(ext2fs_inode_bitmap bitmap,
/* update the bitmap flags, set the itable high watermark, and calculate
* checksums for the group descriptors */
-void ext2fs_set_gdt_csum(ext2_filsys fs)
+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;
- 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)
- return;
+ if (!fs->inode_map)
+ return EXT2_ET_NO_INODE_BITMAP;
+
+ 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;
- /* Even if it wasn't zeroed, by the time this function is
- * called by e2fsck we have already scanned and corrected
- * the whole inode table so we may as well not overwrite it.
- * This is just a hint to the kernel that it could do lazy
- * zeroing of the inode table if mke2fs didn't do it, to help
- * out if we need to do a full itable scan sometime later. */
- if (!(bg->bg_flags & (EXT2_BG_INODE_UNINIT |
- EXT2_BG_INODE_ZEROED)))
- fs->group_desc[i].bg_flags |= EXT2_BG_INODE_ZEROED;
-
- 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) {
+ if (bg->bg_free_inodes_count == sb->s_inodes_per_group) {
+ bg->bg_flags |= EXT2_BG_INODE_UNINIT;
+ bg->bg_itable_unused = sb->s_inodes_per_group;
+ } else {
bg->bg_flags &= ~EXT2_BG_INODE_UNINIT;
bg->bg_itable_unused = sb->s_inodes_per_group -
find_last_inode_ingrp(fs->inode_map,
sb->s_inodes_per_group,i);
}
- /* 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)
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 = &fs->group_desc[group];
+ struct ext2_super_block *sb = fs->super;
+
+#ifdef WORDS_BIGENDIAN
+ struct ext2_group_desc swabdesc = fs->group_desc[group];
+
+ /* Have to swab back to little-endian to do the checksum */
+ ext2fs_swap_group_desc(&swabdesc);
+ 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,
+ offsetof(struct ext2_group_desc, bg_checksum));
+ 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));
+ param.s_blocks_count = 32768;
+
+ retval = ext2fs_initialize("test fs", 0, ¶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++) {
+ fs->group_desc[i].bg_block_bitmap = 124;
+ fs->group_desc[i].bg_inode_bitmap = 125;
+ fs->group_desc[i].bg_inode_table = 126;
+ fs->group_desc[i].bg_free_blocks_count = 31119;
+ fs->group_desc[i].bg_free_inodes_count = 15701;
+ fs->group_desc[i].bg_used_dirs_count = 2;
+ fs->group_desc[i].bg_flags = 0;
+ };
+
+ 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);
+ }
+ fs->group_desc[0].bg_checksum = 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 = fs->group_desc[0].bg_checksum = ext2fs_group_desc_csum(fs, 0);
+ print_csum("csum_new", fs, 0);
+ fs->group_desc[0].bg_free_blocks_count = 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