+static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
+{
+ struct commit_header *h;
+ __u32 provided, calculated;
+
+ if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+ return 1;
+
+ h = buf;
+ provided = h->h_chksum[0];
+ h->h_chksum[0] = 0;
+ calculated = ext2fs_crc32c_le(~0, j->j_superblock->s_uuid,
+ sizeof(j->j_superblock->s_uuid));
+ calculated = ext2fs_crc32c_le(calculated, buf, j->j_blocksize);
+ h->h_chksum[0] = provided;
+
+ provided = ext2fs_be32_to_cpu(provided);
+ return provided == calculated;
+}
+
+static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
+ void *buf, __u32 sequence)
+{
+ __u32 provided, calculated;
+
+ if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+ return 1;
+
+ sequence = ext2fs_cpu_to_be32(sequence);
+ calculated = ext2fs_crc32c_le(~0, j->j_superblock->s_uuid,
+ sizeof(j->j_superblock->s_uuid));
+ calculated = ext2fs_crc32c_le(calculated, (__u8 *)&sequence,
+ sizeof(sequence));
+ calculated = ext2fs_crc32c_le(calculated, buf, j->j_blocksize) & 0xffff;
+ provided = ext2fs_be16_to_cpu(tag->t_checksum);
+
+ return provided == ext2fs_cpu_to_be32(calculated);
+}
+