[PATCH v2] xfs: check v5 superblock features early

When working on a new features that reuses the existing pad in the
superblock, I noticed that mounting such a file system on an old kernel
logs a rather confusing warning:

    XFS (vdc): Metadir superblock padding fields must be zero.

This is because we only validate the various feature fields in v5
superblocks after the common superblock validation helper is called.

Fix this by calling the feature validation first.

Fixes: eca383fcd63b ("xfs: refactor superblock verifiers")
Signed-off-by: Christoph Hellwig <[email protected]>
---

Changes since v1:
 - minimize the fix, and implement all the good ideas later

 fs/xfs/libxfs/xfs_sb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 47322adb7690..75f2a021ee6d 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -1118,10 +1118,10 @@ xfs_sb_read_verify(
 	 * because _verify_common checks the on-disk values.
 	 */
 	__xfs_sb_from_disk(&sb, dsb, false);
-	error = xfs_validate_sb_common(mp, bp, &sb);
+	error = xfs_validate_sb_read(mp, &sb);
 	if (error)
 		goto out_error;
-	error = xfs_validate_sb_read(mp, &sb);
+	error = xfs_validate_sb_common(mp, bp, &sb);
 
 out_error:
 	if (error == -EFSCORRUPTED || error == -EFSBADCRC)
-- 
2.53.0