Commit 00a3fff0 authored by Shijie Luo's avatar Shijie Luo Committed by Theodore Ts'o
Browse files

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


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 70d7ced2

fs/jbd2/recovery.c

+12 −34
Original line number Diff line number Diff line
@@ -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 &&

				/* 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)

				       chksum_seen = 1;

				else if (!(cbh->h_chksum_type == 0 &&

						JBD2_CRC32_CHKSUM_SIZE) ||

				      (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;

				       found_chksum == 0)))

					goto chksum_error;



				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;

					}

				}

				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)) {