ext4: Remove journal_checksum mount option and enable it by default

There's no real cost for the journal checksum feature, and we should
make sure it is enabled all the time.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>


diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4037fe0..f1815d3 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1280,11 +1280,9 @@
 			*journal_devnum = option;
 			break;
 		case Opt_journal_checksum:
-			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
-			break;
+			break;	/* Kept for backwards compatibility */
 		case Opt_journal_async_commit:
 			set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
-			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
 			break;
 		case Opt_noload:
 			set_opt(sbi->s_mount_opt, NOLOAD);
@@ -2751,20 +2749,14 @@
 		goto failed_mount4;
 	}
 
-	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
-		jbd2_journal_set_features(sbi->s_journal,
-				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+	jbd2_journal_set_features(sbi->s_journal,
+				  JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
+	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
+		jbd2_journal_set_features(sbi->s_journal, 0, 0,
 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
-	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
-		jbd2_journal_set_features(sbi->s_journal,
-				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
+	else
 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
-	} else {
-		jbd2_journal_clear_features(sbi->s_journal,
-				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
-				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
-	}
 
 	/* We have now updated the journal if required, so we can
 	 * validate the data journaling mode. */