xfs: add xfs sb v4 support for dirent filetype field

Add XFS superblock v4 support for the file type field in the
directory entry feature.

This support adds a feature bit for version 4 superblocks and
leaves the original superblock 5 incompatibility bit.
Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Geoffrey Wehrman <gwehrman@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_sb.h

@@ -84,11 +84,13 @@ struct xfs_trans;
 #define XFS_SB_VERSION2_PARENTBIT	0x00000010	/* parent pointers */
 #define XFS_SB_VERSION2_PROJID32BIT	0x00000080	/* 32 bit project id */
 #define XFS_SB_VERSION2_CRCBIT		0x00000100	/* metadata CRCs */
+#define XFS_SB_VERSION2_FTYPE		0x00000200	/* inode type in dir */
 
 #define	XFS_SB_VERSION2_OKREALFBITS	\
 	(XFS_SB_VERSION2_LAZYSBCOUNTBIT	| \
 	 XFS_SB_VERSION2_ATTR2BIT	| \
-	 XFS_SB_VERSION2_PROJID32BIT)
+	 XFS_SB_VERSION2_PROJID32BIT	| \
+	 XFS_SB_VERSION2_FTYPE)
 #define	XFS_SB_VERSION2_OKSASHFBITS	\
 	(0)
 #define XFS_SB_VERSION2_OKREALBITS	\
@@ -631,8 +633,10 @@ static inline int xfs_sb_version_has_pquotino(xfs_sb_t *sbp)
 
 static inline int xfs_sb_version_hasftype(struct xfs_sb *sbp)
 {
-	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
-		xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_FTYPE);
+	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
+		xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_FTYPE)) ||
+	       (xfs_sb_version_hasmorebits(sbp) &&
+		 (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE));
 }
 
 /*