xfs: sanitise sb_bad_features2 handling

We currently have to ensure that every time we update sb_features2
that we update sb_bad_features2. Now that we log and format the
superblock in it's entirety we actually don't have to care because
we can simply update the sb_bad_features2 when we format it into the
buffer. This removes the need for anything but the mount and
superblock formatting code to care about sb_bad_features2, and
hence removes the possibility that we forget to update bad_features2
when necessary in the future.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 63f814872dfb..b0a5fe95a3e2 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -497,7 +497,6 @@ xfs_sb_to_disk(
 	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
 	to->sb_frextents = cpu_to_be64(from->sb_frextents);
 
-
 	to->sb_flags = from->sb_flags;
 	to->sb_shared_vn = from->sb_shared_vn;
 	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
@@ -507,6 +506,13 @@ xfs_sb_to_disk(
 	to->sb_logsectlog = from->sb_logsectlog;
 	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
 	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
+
+	/*
+	 * We need to ensure that bad_features2 always matches features2.
+	 * Hence we enforce that here rather than having to remember to do it
+	 * everywhere else that updates features2.
+	 */
+	from->sb_bad_features2 = from->sb_features2;
 	to->sb_features2 = cpu_to_be32(from->sb_features2);
 	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);