1 files changed, 6 insertions, 2 deletions

diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index a476b63e2e60..f0101974f4f9 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -86,7 +86,8 @@
         OCFS2_SB(sb)->s_feature_incompat &= ~(mask)
 
 #define OCFS2_FEATURE_COMPAT_SUPP       OCFS2_FEATURE_COMPAT_BACKUP_SB
-#define OCFS2_FEATURE_INCOMPAT_SUPP     OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT
+#define OCFS2_FEATURE_INCOMPAT_SUPP     (OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT \
+                                         | OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC)
 #define OCFS2_FEATURE_RO_COMPAT_SUPP    0
 
 /*
@@ -311,7 +312,10 @@ struct ocfs2_extent_list {
 /*00*/  __le16 l_tree_depth;            /* Extent tree depth from this
                                            point.  0 means data extents
                                            hang directly off this
-                                           header (a leaf) */
+                                           header (a leaf)
+                                           NOTE: The high 8 bits cannot be
+                                           used - tree_depth is never that big.
+                                        */
         __le16 l_count;                 /* Number of extent records */
         __le16 l_next_free_rec;         /* Next unused extent slot */
         __le16 l_reserved1;