+ if (pass == PASS_SCAN &&
+ JBD2_HAS_COMPAT_FEATURE(journal,
+ JBD2_FEATURE_COMPAT_CHECKSUM)) {
+ int chksum_err, chksum_seen;
+ struct commit_header *cbh =
+ (struct commit_header *)bh->b_data;
+ unsigned found_chksum =
+ be32_to_cpu(cbh->h_chksum[0]);
+
+ chksum_err = chksum_seen = 0;
+
+ if (info->end_transaction) {
+ printk(KERN_ERR "JBD: Transaction %u "
+ "found to be corrupt.\n",
+ next_commit_ID - 1);
+ brelse(bh);
+ break;
+ }
+
+ if (crc32_sum == found_chksum &&
+ cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
+ cbh->h_chksum_size ==
+ JBD2_CRC32_CHKSUM_SIZE)
+ chksum_seen = 1;
+ else if (!(cbh->h_chksum_type == 0 &&
+ cbh->h_chksum_size == 0 &&
+ found_chksum == 0 &&
+ !chksum_seen))
+ /*
+ * If fs is mounted using an old kernel and then
+ * kernel with journal_chksum is used then we
+ * get a situation where the journal flag has
+ * checksum flag set but checksums are not
+ * present i.e chksum = 0, in the individual
+ * commit blocks.
+ * Hence to avoid checksum failures, in this
+ * situation, this extra check is added.
+ */
+ chksum_err = 1;
+
+ if (chksum_err) {
+ info->end_transaction = next_commit_ID;
+
+ if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
+ printk(KERN_ERR
+ "JBD: Transaction %u "
+ "found to be corrupt.\n",
+ next_commit_ID);
+ brelse(bh);
+ break;
+ }
+ }
+ crc32_sum = ~0;
+ }