+static int jbd_has_csum(struct jbd_sb *jbd_sb)
+{
+ if (JBD_HAS_INCOMPAT_FEATURE(jbd_sb, JBD_FEATURE_INCOMPAT_CSUM_V2))
+ return 2;
+
+ if (JBD_HAS_INCOMPAT_FEATURE(jbd_sb, JBD_FEATURE_INCOMPAT_CSUM_V3))
+ return 3;
+
+ return 0;
+}
+
+#if CONFIG_META_CSUM_ENABLE
+static uint32_t jbd_sb_csum(struct jbd_sb *jbd_sb)
+{
+ uint32_t checksum = 0;
+
+ if (jbd_has_csum(jbd_sb)) {
+ uint32_t orig_checksum = jbd_sb->checksum;
+ jbd_set32(jbd_sb, checksum, 0);
+ /* Calculate crc32c checksum against tho whole superblock */
+ checksum = ext4_crc32c(EXT4_CRC32_INIT, jbd_sb,
+ JBD_SUPERBLOCK_SIZE);
+ jbd_sb->checksum = orig_checksum;
+ }
+ return checksum;
+}
+#else
+#define jbd_sb_csum(...) 0
+#endif
+
+static void jbd_sb_csum_set(struct jbd_sb *jbd_sb)
+{
+ if (!jbd_has_csum(jbd_sb))
+ return;
+
+ jbd_set32(jbd_sb, checksum, jbd_sb_csum(jbd_sb));
+}
+
+#if CONFIG_META_CSUM_ENABLE
+static bool
+jbd_verify_sb_csum(struct jbd_sb *jbd_sb)
+{
+ if (!jbd_has_csum(jbd_sb))
+ return true;
+
+ return jbd_sb_csum(jbd_sb) == jbd_get32(jbd_sb, checksum);
+}
+#else
+#define jbd_verify_sb_csum(...) true
+#endif
+
+#if CONFIG_META_CSUM_ENABLE
+static uint32_t jbd_meta_csum(struct jbd_fs *jbd_fs,
+ struct jbd_bhdr *bhdr)
+{
+ uint32_t checksum = 0;
+
+ if (jbd_has_csum(&jbd_fs->sb)) {
+ uint32_t block_size = jbd_get32(&jbd_fs->sb, blocksize);
+ struct jbd_block_tail *tail =
+ (struct jbd_block_tail *)((char *)bhdr + block_size -
+ sizeof(struct jbd_block_tail));
+ uint32_t orig_checksum = tail->checksum;
+ tail->checksum = 0;
+
+ /* First calculate crc32c checksum against fs uuid */
+ checksum = ext4_crc32c(EXT4_CRC32_INIT, jbd_fs->sb.uuid,
+ sizeof(jbd_fs->sb.uuid));
+ /* Calculate crc32c checksum against tho whole block */
+ checksum = ext4_crc32c(checksum, bhdr,
+ block_size);
+ tail->checksum = orig_checksum;
+ }
+ return checksum;
+}
+#else
+#define jbd_meta_csum(...) 0
+#endif
+
+static void jbd_meta_csum_set(struct jbd_fs *jbd_fs,
+ struct jbd_bhdr *bhdr)
+{
+ uint32_t block_size = jbd_get32(&jbd_fs->sb, blocksize);
+ struct jbd_block_tail *tail = (struct jbd_block_tail *)
+ ((char *)bhdr + block_size -
+ sizeof(struct jbd_block_tail));
+ if (!jbd_has_csum(&jbd_fs->sb))
+ return;
+
+ tail->checksum = to_be32(jbd_meta_csum(jbd_fs, bhdr));
+}
+
+#if CONFIG_META_CSUM_ENABLE
+static bool
+jbd_verify_meta_csum(struct jbd_fs *jbd_fs,
+ struct jbd_bhdr *bhdr)
+{
+ uint32_t block_size = jbd_get32(&jbd_fs->sb, blocksize);
+ struct jbd_block_tail *tail = (struct jbd_block_tail *)
+ ((char *)bhdr + block_size -
+ sizeof(struct jbd_block_tail));
+ if (!jbd_has_csum(&jbd_fs->sb))
+ return true;
+
+ return jbd_meta_csum(jbd_fs, bhdr) == to_be32(tail->checksum);
+}
+#else
+#define jbd_verify_meta_csum(...) true
+#endif
+
+#if CONFIG_META_CSUM_ENABLE
+static uint32_t jbd_commit_csum(struct jbd_fs *jbd_fs,
+ struct jbd_commit_header *header)
+{
+ uint32_t checksum = 0;
+
+ if (jbd_has_csum(&jbd_fs->sb)) {
+ uint32_t orig_checksum_type = header->chksum_type,
+ orig_checksum_size = header->chksum_size,
+ orig_checksum = header->chksum[0];
+ uint32_t block_size = jbd_get32(&jbd_fs->sb, blocksize);
+ header->chksum_type = 0;
+ header->chksum_size = 0;
+ header->chksum[0] = 0;
+
+ /* First calculate crc32c checksum against fs uuid */
+ checksum = ext4_crc32c(EXT4_CRC32_INIT, jbd_fs->sb.uuid,
+ sizeof(jbd_fs->sb.uuid));
+ /* Calculate crc32c checksum against tho whole block */
+ checksum = ext4_crc32c(checksum, header,
+ block_size);
+
+ header->chksum_type = orig_checksum_type;
+ header->chksum_size = orig_checksum_size;
+ header->chksum[0] = orig_checksum;
+ }
+ return checksum;
+}
+#else
+#define jbd_commit_csum(...) 0
+#endif
+
+static void jbd_commit_csum_set(struct jbd_fs *jbd_fs,
+ struct jbd_commit_header *header)
+{
+ if (!jbd_has_csum(&jbd_fs->sb))
+ return;
+
+ header->chksum_type = 0;
+ header->chksum_size = 0;
+ header->chksum[0] = jbd_commit_csum(jbd_fs, header);
+}
+
+#if CONFIG_META_CSUM_ENABLE
+static bool jbd_verify_commit_csum(struct jbd_fs *jbd_fs,
+ struct jbd_commit_header *header)
+{
+ if (!jbd_has_csum(&jbd_fs->sb))
+ return true;
+
+ return header->chksum[0] == to_be32(jbd_commit_csum(jbd_fs,
+ header));
+}
+#else
+#define jbd_verify_commit_csum(...) true
+#endif
+
+#if CONFIG_META_CSUM_ENABLE
+/*
+ * NOTE: We only make use of @csum parameter when
+ * JBD_FEATURE_COMPAT_CHECKSUM is enabled.
+ */
+static uint32_t jbd_block_csum(struct jbd_fs *jbd_fs, const void *buf,
+ uint32_t csum,
+ uint32_t sequence)
+{
+ uint32_t checksum = 0;
+
+ if (jbd_has_csum(&jbd_fs->sb)) {
+ uint32_t block_size = jbd_get32(&jbd_fs->sb, blocksize);
+ /* First calculate crc32c checksum against fs uuid */
+ checksum = ext4_crc32c(EXT4_CRC32_INIT, jbd_fs->sb.uuid,
+ sizeof(jbd_fs->sb.uuid));
+ /* Then calculate crc32c checksum against sequence no. */
+ checksum = ext4_crc32c(checksum, &sequence,
+ sizeof(uint32_t));
+ /* Calculate crc32c checksum against tho whole block */
+ checksum = ext4_crc32c(checksum, buf,
+ block_size);
+ } else if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
+ JBD_FEATURE_COMPAT_CHECKSUM)) {
+ uint32_t block_size = jbd_get32(&jbd_fs->sb, blocksize);
+ /* Calculate crc32c checksum against tho whole block */
+ checksum = ext4_crc32(csum, buf,
+ block_size);
+ }
+ return checksum;
+}
+#else
+#define jbd_block_csum(...) 0
+#endif
+
+static void jbd_block_tag_csum_set(struct jbd_fs *jbd_fs, void *__tag,
+ uint32_t checksum)
+{
+ int ver = jbd_has_csum(&jbd_fs->sb);
+ if (!ver)
+ return;
+
+ if (ver == 2) {
+ struct jbd_block_tag *tag = __tag;
+ tag->checksum = (uint16_t)to_be32(checksum);
+ } else {
+ struct jbd_block_tag3 *tag = __tag;
+ tag->checksum = to_be32(checksum);
+ }
+}