ext4: enable journal checksum when metadata checksum feature enabled

If metadata checksumming is turned on for the FS, we need to tell the
journal to use checksumming too.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1eda6ab..5c11e21 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3526,6 +3526,10 @@
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 	set_opt(sb, POSIX_ACL);
 #endif
+	/* don't forget to enable journal_csum when metadata_csum is enabled. */
+	if (ext4_has_metadata_csum(sb))
+		set_opt(sb, JOURNAL_CHECKSUM);
+
 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
 		set_opt(sb, JOURNAL_DATA);
 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)