Adding upstream version 1.47.0.upstream/1.47.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1011 insertions, 0 deletions

diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c
new file mode 100644
index 0000000..da32d94
--- /dev/null
+++ b/lib/ext2fs/csum.c
@@ -0,0 +1,1011 @@
+/*
+ * 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 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"
+#include <assert.h>
+
+#ifndef offsetof
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+#endif
+
+#ifdef DEBUG
+#define STATIC
+#else
+#define STATIC static
+#endif
+
+void ext2fs_init_csum_seed(ext2_filsys fs)
+{
+	if (ext2fs_has_feature_csum_seed(fs->super))
+		fs->csum_seed = fs->super->s_checksum_seed;
+	else if (ext2fs_has_feature_metadata_csum(fs->super) ||
+		 ext2fs_has_feature_ea_inode(fs->super))
+		fs->csum_seed = ext2fs_crc32c_le(~0, fs->super->s_uuid,
+						 sizeof(fs->super->s_uuid));
+}
+
+static __u32 ext2fs_mmp_csum(ext2_filsys fs, struct mmp_struct *mmp)
+{
+	int offset = offsetof(struct mmp_struct, mmp_checksum);
+
+	return ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)mmp, offset);
+}
+
+int ext2fs_mmp_csum_verify(ext2_filsys fs, struct mmp_struct *mmp)
+{
+	__u32 calculated;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+
+	calculated = ext2fs_mmp_csum(fs, mmp);
+
+	return ext2fs_le32_to_cpu(mmp->mmp_checksum) == calculated;
+}
+
+errcode_t ext2fs_mmp_csum_set(ext2_filsys fs, struct mmp_struct *mmp)
+{
+	__u32 crc;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 0;
+
+	crc = ext2fs_mmp_csum(fs, mmp);
+	mmp->mmp_checksum = ext2fs_cpu_to_le32(crc);
+
+	return 0;
+}
+
+int ext2fs_verify_csum_type(ext2_filsys fs, struct ext2_super_block *sb)
+{
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+
+	return sb->s_checksum_type == EXT2_CRC32C_CHKSUM;
+}
+
+static __u32 ext2fs_superblock_csum(ext2_filsys fs EXT2FS_ATTR((unused)),
+				    struct ext2_super_block *sb)
+{
+	int offset = offsetof(struct ext2_super_block, s_checksum);
+
+	return ext2fs_crc32c_le(~0, (unsigned char *)sb, offset);
+}
+
+/* NOTE: The input to this function MUST be in LE order */
+int ext2fs_superblock_csum_verify(ext2_filsys fs, struct ext2_super_block *sb)
+{
+	__u32 flag, calculated;
+
+	if (fs->flags & EXT2_FLAG_SWAP_BYTES)
+		flag = EXT4_FEATURE_RO_COMPAT_METADATA_CSUM;
+	else
+		flag = ext2fs_cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
+
+	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, flag))
+		return 1;
+
+	calculated = ext2fs_superblock_csum(fs, sb);
+
+	return ext2fs_le32_to_cpu(sb->s_checksum) == calculated;
+}
+
+/* NOTE: The input to this function MUST be in LE order */
+errcode_t ext2fs_superblock_csum_set(ext2_filsys fs,
+				     struct ext2_super_block *sb)
+{
+	__u32 flag, crc;
+
+	if (fs->flags & EXT2_FLAG_SWAP_BYTES)
+		flag = EXT4_FEATURE_RO_COMPAT_METADATA_CSUM;
+	else
+		flag = ext2fs_cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
+
+	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, flag))
+		return 0;
+
+	crc = ext2fs_superblock_csum(fs, sb);
+	sb->s_checksum = ext2fs_cpu_to_le32(crc);
+
+	return 0;
+}
+
+static errcode_t ext2fs_ext_attr_block_csum(ext2_filsys fs,
+					    ext2_ino_t inum EXT2FS_ATTR((unused)),
+					    blk64_t block,
+					    struct ext2_ext_attr_header *hdr,
+					    __u32 *crc)
+{
+	char *buf = (char *)hdr;
+	__u32 old_crc = hdr->h_checksum;
+
+	hdr->h_checksum = 0;
+	block = ext2fs_cpu_to_le64(block);
+	*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&block,
+				sizeof(block));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, fs->blocksize);
+	hdr->h_checksum = old_crc;
+
+	return 0;
+}
+
+int ext2fs_ext_attr_block_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+				      blk64_t block,
+				      struct ext2_ext_attr_header *hdr)
+{
+	__u32 calculated;
+	errcode_t retval;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+
+	retval = ext2fs_ext_attr_block_csum(fs, inum, block, hdr, &calculated);
+	if (retval)
+		return 0;
+
+	return ext2fs_le32_to_cpu(hdr->h_checksum) == calculated;
+}
+
+errcode_t ext2fs_ext_attr_block_csum_set(ext2_filsys fs, ext2_ino_t inum,
+					 blk64_t block,
+					 struct ext2_ext_attr_header *hdr)
+{
+	errcode_t retval;
+	__u32 crc;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 0;
+
+	retval = ext2fs_ext_attr_block_csum(fs, inum, block, hdr, &crc);
+	if (retval)
+		return retval;
+	hdr->h_checksum = ext2fs_cpu_to_le32(crc);
+	return 0;
+}
+
+static __u16 do_nothing16(__u16 x)
+{
+	return x;
+}
+
+static __u16 disk_to_host16(__u16 x)
+{
+	return ext2fs_le16_to_cpu(x);
+}
+
+static errcode_t __get_dx_countlimit(ext2_filsys fs,
+				     struct ext2_dir_entry *dirent,
+				     struct ext2_dx_countlimit **cc,
+				     int *offset,
+				     int need_swab)
+{
+	struct ext2_dir_entry *dp;
+	struct ext2_dx_root_info *root;
+	struct ext2_dx_countlimit *c;
+	int count_offset, max_sane_entries;
+	unsigned int rec_len;
+	__u16 (*translate)(__u16) = (need_swab ? disk_to_host16 : do_nothing16);
+
+	rec_len = translate(dirent->rec_len);
+
+	if (rec_len == fs->blocksize && translate(dirent->name_len) == 0)
+		count_offset = 8;
+	else if (rec_len == 12) {
+		dp = (struct ext2_dir_entry *)(((char *)dirent) + rec_len);
+		rec_len = translate(dp->rec_len);
+		if (rec_len != fs->blocksize - 12)
+			return EXT2_ET_DB_NOT_FOUND;
+		root = (struct ext2_dx_root_info *)(((char *)dp + 12));
+		if (root->reserved_zero ||
+		    root->info_length != sizeof(struct ext2_dx_root_info))
+			return EXT2_ET_DB_NOT_FOUND;
+		count_offset = 32;
+	} else
+		return EXT2_ET_DB_NOT_FOUND;
+
+	c = (struct ext2_dx_countlimit *)(((char *)dirent) + count_offset);
+	max_sane_entries = (fs->blocksize - count_offset) /
+			   sizeof(struct ext2_dx_entry);
+	if (ext2fs_le16_to_cpu(c->limit) > max_sane_entries ||
+	    ext2fs_le16_to_cpu(c->count) > max_sane_entries)
+		return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
+
+	if (offset)
+		*offset = count_offset;
+	if (cc)
+		*cc = c;
+
+	return 0;
+}
+
+errcode_t ext2fs_get_dx_countlimit(ext2_filsys fs,
+				   struct ext2_dir_entry *dirent,
+				   struct ext2_dx_countlimit **cc,
+				   int *offset)
+{
+	return __get_dx_countlimit(fs, dirent, cc, offset, 0);
+}
+
+void ext2fs_initialize_dirent_tail(ext2_filsys fs,
+				   struct ext2_dir_entry_tail *t)
+{
+	memset(t, 0, sizeof(struct ext2_dir_entry_tail));
+	ext2fs_set_rec_len(fs, sizeof(struct ext2_dir_entry_tail),
+			   (struct ext2_dir_entry *)t);
+	t->det_reserved_name_len = EXT2_DIR_NAME_LEN_CSUM;
+}
+
+static errcode_t __get_dirent_tail(ext2_filsys fs,
+				   struct ext2_dir_entry *dirent,
+				   struct ext2_dir_entry_tail **tt,
+				   int need_swab)
+{
+	struct ext2_dir_entry *d;
+	void *top;
+	struct ext2_dir_entry_tail *t;
+	unsigned int rec_len;
+	errcode_t retval = 0;
+	__u16 (*translate)(__u16) = (need_swab ? disk_to_host16 : do_nothing16);
+
+	if (fs->blocksize < 1024)
+		return EXT2_FILSYS_CORRUPTED; /* Should never happen */
+
+	d = dirent;
+	top = EXT2_DIRENT_TAIL(dirent, fs->blocksize);
+
+	while ((void *) d < top) {
+		rec_len = translate(d->rec_len);
+		if ((rec_len < 8) || (rec_len & 0x03))
+			return EXT2_ET_DIR_CORRUPTED;
+		d = (struct ext2_dir_entry *)(((char *)d) + rec_len);
+	}
+
+	if ((char *)d > ((char *)dirent + fs->blocksize))
+			return EXT2_ET_DIR_CORRUPTED;
+	if (d != top)
+		return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
+
+	t = (struct ext2_dir_entry_tail *)d;
+	if (t->det_reserved_zero1 ||
+	    translate(t->det_rec_len) != sizeof(struct ext2_dir_entry_tail) ||
+	    translate(t->det_reserved_name_len) != EXT2_DIR_NAME_LEN_CSUM)
+		return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
+
+	if (tt)
+		*tt = t;
+	return retval;
+}
+
+int ext2fs_dirent_has_tail(ext2_filsys fs, struct ext2_dir_entry *dirent)
+{
+	return __get_dirent_tail(fs, dirent, NULL, 0) !=
+		EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
+}
+
+static errcode_t ext2fs_dirent_csum(ext2_filsys fs, ext2_ino_t inum,
+				    struct ext2_dir_entry *dirent, __u32 *crc,
+				    int size)
+{
+	errcode_t retval;
+	char *buf = (char *)dirent;
+	__u32 gen;
+	struct ext2_inode inode;
+
+	retval = ext2fs_read_inode(fs, inum, &inode);
+	if (retval)
+		return retval;
+
+	inum = ext2fs_cpu_to_le32(inum);
+	gen = ext2fs_cpu_to_le32(inode.i_generation);
+	*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
+				sizeof(inum));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, size);
+
+	return 0;
+}
+
+int ext2fs_dirent_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+			      struct ext2_dir_entry *dirent)
+{
+	errcode_t retval;
+	__u32 calculated;
+	struct ext2_dir_entry_tail *t;
+
+	retval = __get_dirent_tail(fs, dirent, &t, 1);
+	if (retval)
+		return 1;
+
+	/*
+	 * The checksum field is overlaid with the dirent->name field
+	 * so the swapfs.c functions won't change the endianness.
+	 */
+	retval = ext2fs_dirent_csum(fs, inum, dirent, &calculated,
+				    (char *)t - (char *)dirent);
+	if (retval)
+		return 0;
+	return ext2fs_le32_to_cpu(t->det_checksum) == calculated;
+}
+
+static errcode_t ext2fs_dirent_csum_set(ext2_filsys fs, ext2_ino_t inum,
+					struct ext2_dir_entry *dirent)
+{
+	errcode_t retval;
+	__u32 crc;
+	struct ext2_dir_entry_tail *t;
+
+	retval = __get_dirent_tail(fs, dirent, &t, 1);
+	if (retval)
+		return retval;
+
+	/* swapfs.c functions don't change the checksum endianness */
+	retval = ext2fs_dirent_csum(fs, inum, dirent, &crc,
+				    (char *)t - (char *)dirent);
+	if (retval)
+		return retval;
+	t->det_checksum = ext2fs_cpu_to_le32(crc);
+	return 0;
+}
+
+errcode_t ext2fs_dx_csum(ext2_filsys fs, ext2_ino_t inum,
+			 struct ext2_dir_entry *dirent,
+			 __u32 *crc, struct ext2_dx_tail **ret_t)
+{
+	errcode_t retval;
+	char *buf = (char *)dirent;
+	int size;
+	__u32 gen, dummy_csum = 0;
+	struct ext2_inode inode;
+	struct ext2_dx_tail *t;
+	struct ext2_dx_countlimit *c;
+	int count_offset, limit, count;
+
+	retval = __get_dx_countlimit(fs, dirent, &c, &count_offset, 1);
+	if (retval)
+		return retval;
+	limit = ext2fs_le16_to_cpu(c->limit);
+	count = ext2fs_le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
+	    fs->blocksize - sizeof(struct ext2_dx_tail))
+		return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
+	/* htree structs are accessed in LE order */
+	t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit);
+
+	size = count_offset + (count * sizeof(struct ext2_dx_entry));
+
+	retval = ext2fs_read_inode(fs, inum, &inode);
+	if (retval)
+		return retval;
+
+	inum = ext2fs_cpu_to_le32(inum);
+	gen = ext2fs_cpu_to_le32(inode.i_generation);
+	*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
+				sizeof(inum));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, size);
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)t, 4);
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&dummy_csum, 4);
+
+	if (ret_t)
+		*ret_t = t;
+	return 0;
+}
+
+static int ext2fs_dx_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+				 struct ext2_dir_entry *dirent)
+{
+	__u32 calculated;
+	errcode_t retval;
+	struct ext2_dx_tail *t;
+
+	retval = ext2fs_dx_csum(fs, inum, dirent, &calculated, &t);
+	if (retval)
+		return 0;
+
+	return ext2fs_le32_to_cpu(t->dt_checksum) == calculated;
+}
+
+static errcode_t ext2fs_dx_csum_set(ext2_filsys fs, ext2_ino_t inum,
+				    struct ext2_dir_entry *dirent)
+{
+	__u32 crc;
+	errcode_t retval = 0;
+	struct ext2_dx_tail *t;
+
+	retval = ext2fs_dx_csum(fs, inum, dirent, &crc, &t);
+	if (retval)
+		return retval;
+	t->dt_checksum = ext2fs_cpu_to_le32(crc);
+	return retval;
+}
+
+int ext2fs_dir_block_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+				 struct ext2_dir_entry *dirent)
+{
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+
+	if (__get_dirent_tail(fs, dirent, NULL, 1) == 0)
+		return ext2fs_dirent_csum_verify(fs, inum, dirent);
+	if (__get_dx_countlimit(fs, dirent, NULL, NULL, 1) == 0)
+		return ext2fs_dx_csum_verify(fs, inum, dirent);
+
+	return 0;
+}
+
+errcode_t ext2fs_dir_block_csum_set(ext2_filsys fs, ext2_ino_t inum,
+				    struct ext2_dir_entry *dirent)
+{
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 0;
+
+	if (__get_dirent_tail(fs, dirent, NULL, 1) == 0)
+		return ext2fs_dirent_csum_set(fs, inum, dirent);
+	if (__get_dx_countlimit(fs, dirent, NULL, NULL, 1) == 0)
+		return ext2fs_dx_csum_set(fs, inum, dirent);
+
+	if (fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS)
+		return 0;
+	return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
+}
+
+#define EXT3_EXTENT_TAIL_OFFSET(hdr)	(sizeof(struct ext3_extent_header) + \
+	(sizeof(struct ext3_extent) * ext2fs_le16_to_cpu((hdr)->eh_max)))
+
+static struct ext3_extent_tail *get_extent_tail(struct ext3_extent_header *h)
+{
+	return (struct ext3_extent_tail *)(((char *)h) +
+					   EXT3_EXTENT_TAIL_OFFSET(h));
+}
+
+static errcode_t ext2fs_extent_block_csum(ext2_filsys fs, ext2_ino_t inum,
+					  struct ext3_extent_header *eh,
+					  __u32 *crc)
+{
+	int size;
+	__u32 gen;
+	errcode_t retval;
+	struct ext2_inode inode;
+
+	size = EXT3_EXTENT_TAIL_OFFSET(eh) + offsetof(struct ext3_extent_tail,
+						      et_checksum);
+
+	retval = ext2fs_read_inode(fs, inum, &inode);
+	if (retval)
+		return retval;
+	inum = ext2fs_cpu_to_le32(inum);
+	gen = ext2fs_cpu_to_le32(inode.i_generation);
+	*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
+				sizeof(inum));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)eh, size);
+
+	return 0;
+}
+
+int ext2fs_extent_block_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+				    struct ext3_extent_header *eh)
+{
+	errcode_t retval;
+	__u32 provided, calculated;
+	struct ext3_extent_tail *t = get_extent_tail(eh);
+
+	/*
+	 * The extent tree structures are accessed in LE order, so we must
+	 * swap the checksum bytes here.
+	 */
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+
+	provided = ext2fs_le32_to_cpu(t->et_checksum);
+	retval = ext2fs_extent_block_csum(fs, inum, eh, &calculated);
+	if (retval)
+		return 0;
+
+	return provided == calculated;
+}
+
+errcode_t ext2fs_extent_block_csum_set(ext2_filsys fs, ext2_ino_t inum,
+				       struct ext3_extent_header *eh)
+{
+	errcode_t retval;
+	__u32 crc;
+	struct ext3_extent_tail *t = get_extent_tail(eh);
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 0;
+
+	/*
+	 * The extent tree structures are accessed in LE order, so we must
+	 * swap the checksum bytes here.
+	 */
+	retval = ext2fs_extent_block_csum(fs, inum, eh, &crc);
+	if (retval)
+		return retval;
+	t->et_checksum = ext2fs_cpu_to_le32(crc);
+	return retval;
+}
+
+int ext2fs_inode_bitmap_csum_verify(ext2_filsys fs, dgrp_t group,
+				    char *bitmap, int size)
+{
+	struct ext4_group_desc *gdp = (struct ext4_group_desc *)
+			ext2fs_group_desc(fs, fs->group_desc, group);
+	__u32 provided, calculated;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+	provided = gdp->bg_inode_bitmap_csum_lo;
+	calculated = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap,
+				      size);
+	if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
+		provided |= (__u32)gdp->bg_inode_bitmap_csum_hi << 16;
+	else
+		calculated &= 0xFFFF;
+
+	return provided == calculated;
+}
+
+errcode_t ext2fs_inode_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
+				       char *bitmap, int size)
+{
+	__u32 crc;
+	struct ext4_group_desc *gdp = (struct ext4_group_desc *)
+			ext2fs_group_desc(fs, fs->group_desc, group);
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 0;
+
+	crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap, size);
+	gdp->bg_inode_bitmap_csum_lo = crc & 0xFFFF;
+	if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
+		gdp->bg_inode_bitmap_csum_hi = crc >> 16;
+
+	return 0;
+}
+
+int ext2fs_block_bitmap_csum_verify(ext2_filsys fs, dgrp_t group,
+				    char *bitmap, int size)
+{
+	struct ext4_group_desc *gdp = (struct ext4_group_desc *)
+			ext2fs_group_desc(fs, fs->group_desc, group);
+	__u32 provided, calculated;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+	provided = gdp->bg_block_bitmap_csum_lo;
+	calculated = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap,
+				      size);
+	if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
+		provided |= (__u32)gdp->bg_block_bitmap_csum_hi << 16;
+	else
+		calculated &= 0xFFFF;
+
+	return provided == calculated;
+}
+
+errcode_t ext2fs_block_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
+				       char *bitmap, int size)
+{
+	__u32 crc;
+	struct ext4_group_desc *gdp = (struct ext4_group_desc *)
+			ext2fs_group_desc(fs, fs->group_desc, group);
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 0;
+
+	crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap, size);
+	gdp->bg_block_bitmap_csum_lo = crc & 0xFFFF;
+	if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
+		gdp->bg_block_bitmap_csum_hi = crc >> 16;
+
+	return 0;
+}
+
+static errcode_t ext2fs_inode_csum(ext2_filsys fs, ext2_ino_t inum,
+			       struct ext2_inode_large *inode,
+			       __u32 *crc, int has_hi)
+{
+	__u32 gen;
+	struct ext2_inode_large *desc = inode;
+	size_t size = EXT2_INODE_SIZE(fs->super);
+	__u16 old_lo;
+	__u16 old_hi = 0;
+
+	old_lo = inode->i_checksum_lo;
+	inode->i_checksum_lo = 0;
+	if (has_hi) {
+		old_hi = inode->i_checksum_hi;
+		inode->i_checksum_hi = 0;
+	}
+
+	inum = ext2fs_cpu_to_le32(inum);
+	gen = inode->i_generation;
+	*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
+				sizeof(inum));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
+	*crc = ext2fs_crc32c_le(*crc, (unsigned char *)desc, size);
+
+	inode->i_checksum_lo = old_lo;
+	if (has_hi)
+		inode->i_checksum_hi = old_hi;
+	return 0;
+}
+
+int ext2fs_inode_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+			     struct ext2_inode_large *inode)
+{
+	errcode_t retval;
+	__u32 provided, calculated;
+	unsigned int i, has_hi;
+	char *cp;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 1;
+
+	has_hi = (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE &&
+		  inode->i_extra_isize >= EXT4_INODE_CSUM_HI_EXTRA_END);
+
+	provided = ext2fs_le16_to_cpu(inode->i_checksum_lo);
+	retval = ext2fs_inode_csum(fs, inum, inode, &calculated, has_hi);
+	if (retval)
+		return 0;
+	if (has_hi) {
+		__u32 hi = ext2fs_le16_to_cpu(inode->i_checksum_hi);
+		provided |= hi << 16;
+	} else
+		calculated &= 0xFFFF;
+
+	if (provided == calculated)
+		return 1;
+
+	/*
+	 * If the checksum didn't match, it's possible it was due to
+	 * the inode being all zero's.  It's unlikely this is the
+	 * case, but it can happen.  So check for it here.  (We only
+	 * check the base inode since that's good enough, and it's not
+	 * worth the bother to figure out how much of the extended
+	 * inode, if any, is present.)
+	 */
+	for (cp = (char *) inode, i = 0;
+	     i < sizeof(struct ext2_inode);
+	     cp++, i++)
+		if (*cp)
+			return 0;
+	return 1;		/* Inode must have been all zero's */
+}
+
+errcode_t ext2fs_inode_csum_set(ext2_filsys fs, ext2_ino_t inum,
+			   struct ext2_inode_large *inode)
+{
+	errcode_t retval;
+	__u32 crc;
+	int has_hi;
+
+	if (!ext2fs_has_feature_metadata_csum(fs->super))
+		return 0;
+
+	has_hi = (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE &&
+		  inode->i_extra_isize >= EXT4_INODE_CSUM_HI_EXTRA_END);
+
+	retval = ext2fs_inode_csum(fs, inum, inode, &crc, has_hi);
+	if (retval)
+		return retval;
+	inode->i_checksum_lo = ext2fs_cpu_to_le16(crc & 0xFFFF);
+	if (has_hi)
+		inode->i_checksum_hi = ext2fs_cpu_to_le16(crc >> 16);
+	return 0;
+}
+
+__u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group)
+{
+	struct ext2_group_desc *desc = ext2fs_group_desc(fs, fs->group_desc,
+							 group);
+	size_t offset, size = EXT2_DESC_SIZE(fs->super);
+	__u16 crc = 0;
+#ifdef WORDS_BIGENDIAN
+	struct ext4_group_desc swabdesc;
+	size_t save_size = size;
+	const size_t ext4_bg_size = sizeof(struct ext4_group_desc);
+	struct ext2_group_desc *save_desc = desc;
+
+	/* Have to swab back to little-endian to do the checksum */
+	if (size > ext4_bg_size)
+		size = ext4_bg_size;
+	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
+
+	if (ext2fs_has_feature_metadata_csum(fs->super)) {
+		/* new metadata csum code */
+		__u16 old_crc;
+		__u32 crc32;
+
+		old_crc = desc->bg_checksum;
+		desc->bg_checksum = 0;
+		crc32 = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&group,
+					 sizeof(group));
+		crc32 = ext2fs_crc32c_le(crc32, (unsigned char *)desc,
+					 size);
+		desc->bg_checksum = old_crc;
+#ifdef WORDS_BIGENDIAN
+		if (save_size > ext4_bg_size)
+			crc32 = ext2fs_crc32c_le(crc32,
+				     (unsigned char *)save_desc + ext4_bg_size,
+	                             save_size - ext4_bg_size);
+#endif
+		crc = crc32 & 0xFFFF;
+		goto out;
+	}
+
+	/* old crc16 code */
+	offset = offsetof(struct ext2_group_desc, bg_checksum);
+	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 */
+	/* for checksum of struct ext4_group_desc do the rest...*/
+	if (offset < size) {
+		crc = ext2fs_crc16(crc, (char *)desc + offset,
+				   size - offset);
+	}
+#ifdef WORDS_BIGENDIAN
+	/*
+	 * If the size of the bg descriptor is greater than 64
+	 * bytes, which is the size of the traditional ext4 bg
+	 * descriptor, checksum the rest of the descriptor here
+	 */
+	if (save_size > ext4_bg_size)
+		crc = ext2fs_crc16(crc, (char *)save_desc + ext4_bg_size,
+				   save_size - ext4_bg_size);
+#endif
+
+out:
+	return crc;
+}
+
+int ext2fs_group_desc_csum_verify(ext2_filsys fs, dgrp_t group)
+{
+	if (ext2fs_has_group_desc_csum(fs) &&
+	    (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)
+{
+	if (!ext2fs_has_group_desc_csum(fs))
+		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,
+				   __u32 inodes_per_grp, dgrp_t grp_no)
+{
+	ext2_ino_t i, start_ino, end_ino;
+
+	start_ino = grp_no * inodes_per_grp + 1;
+	end_ino = start_ino + inodes_per_grp - 1;
+
+	for (i = end_ino; i >= start_ino; i--) {
+		if (ext2fs_fast_test_inode_bitmap2(bitmap, i))
+			return i - start_ino + 1;
+	}
+	return inodes_per_grp;
+}
+
+/* update the bitmap flags, set the itable high watermark, and calculate
+ * checksums for the group descriptors */
+errcode_t ext2fs_set_gdt_csum(ext2_filsys fs)
+{
+	struct ext2_super_block *sb = fs->super;
+	int dirty = 0;
+	dgrp_t i;
+
+	if (!fs->inode_map)
+		return EXT2_ET_NO_INODE_BITMAP;
+
+	if (!ext2fs_has_group_desc_csum(fs))
+		return 0;
+
+	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);
+		__u32 old_free_blocks_count = ext2fs_bg_free_blocks_count(fs, i);
+
+		if (old_free_blocks_count == sb->s_blocks_per_group &&
+		    i != fs->group_desc_count - 1)
+			ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
+
+		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);
+
+			ext2fs_bg_flags_clear(fs, i, EXT2_BG_INODE_UNINIT);
+			ext2fs_bg_itable_unused_set(fs, i, unused);
+		}
+
+		ext2fs_group_desc_csum_set(fs, i);
+		if (old_flags != ext2fs_bg_flags(fs, i))
+			dirty = 1;
+		if (old_unused != ext2fs_bg_itable_unused(fs, i))
+			dirty = 1;
+		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 = EXT2_DESC_SIZE(fs->super);
+	struct ext2_super_block *sb = fs->super;
+	int offset = offsetof(struct ext2_group_desc, bg_checksum);
+#ifdef WORDS_BIGENDIAN
+	struct ext4_group_desc swabdesc;
+	struct ext2_group_desc *save_desc = desc;
+	const size_t ext4_bg_size = sizeof(struct ext4_group_desc);
+	size_t save_size = size;
+#endif
+
+#ifdef WORDS_BIGENDIAN
+	/* Have to swab back to little-endian to do the checksum */
+	if (size > ext4_bg_size)
+		size = ext4_bg_size;
+	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);
+#ifdef WORDS_BIGENDIAN
+	if (save_size > ext4_bg_size)
+		crc3 = ext2fs_crc16(crc3, (char *)save_desc + ext4_bg_size,
+				    save_size - ext4_bg_size);
+#endif
+
+	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(&param, 0, sizeof(param));
+	ext2fs_blocks_count_set(&param, 32768);
+#if 0
+	param.s_feature_incompat |= EXT4_FEATURE_INCOMPAT_64BIT;
+	param.s_desc_size = 128;
+	csum_known = 0x5b6e;
+#endif
+
+	retval = ext2fs_initialize("test fs", EXT2_FLAG_64BITS, &param,
+				   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);
+	}
+	ext2fs_free(fs);
+
+	return 0;
+}
+#endif