jbd2: clean up checksum verification in do_one_pass()

Remove the unnecessary chksum_err and checksum_seen variables as well as
some redundant code to make the function easier to understand.

[ With changes suggested by jack@ and tytso@ ]

Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200819122955.33526-1-luoshijie1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 2ed278f0dcede6888110ca98930cb06d160f6957..faa97d748474d5470a541e1760f6e83345a4671f 100644 (file)
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -690,14 +690,11 @@ static int do_one_pass(journal_t *journal,
                         * number. */
                        if (pass == PASS_SCAN &&
                            jbd2_has_feature_checksum(journal)) {
-                               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) {
                                        journal->j_failed_commit =
                                                info->end_transaction;
@@ -705,42 +702,23 @@ static int do_one_pass(journal_t *journal,
                                        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_feature_async_commit(journal)) {
-                                               journal->j_failed_commit =
-                                                       next_commit_ID;
-                                               brelse(bh);
-                                               break;
-                                       }
-                               }
+                               /* Neither checksum match nor unused? */
+                               if (!((crc32_sum == found_chksum &&
+                                      cbh->h_chksum_type ==
+                                               JBD2_CRC32_CHKSUM &&
+                                      cbh->h_chksum_size ==
+                                               JBD2_CRC32_CHKSUM_SIZE) ||
+                                     (cbh->h_chksum_type == 0 &&
+                                      cbh->h_chksum_size == 0 &&
+                                      found_chksum == 0)))
+                                       goto chksum_error;
+
                                crc32_sum = ~0;
                        }
                        if (pass == PASS_SCAN &&
                            !jbd2_commit_block_csum_verify(journal,
                                                           bh->b_data)) {
+                       chksum_error:
                                info->end_transaction = next_commit_ID;
 
                                if (!jbd2_has_feature_async_commit(journal)) {