fat: restructure export_operations

Define two nfs export_operation structures,one for 'stale_rw' mounts and
the other for 'nostale_ro'.  The latter uses i_pos as a basis for encoding
and decoding file handles.

Also, assign i_pos to kstat->ino.  The logic for rebuilding the inode is
added in the subsequent patches.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ravishankar N <ravi.n1@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
index 5b9b5b3..41b223a 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -85,6 +85,17 @@
 	FILEID_NILFS_WITH_PARENT = 0x62,
 
 	/*
+	 * 32 bit generation number, 40 bit i_pos.
+	 */
+	FILEID_FAT_WITHOUT_PARENT = 0x71,
+
+	/*
+	 * 32 bit generation number, 40 bit i_pos,
+	 * 32 bit parent generation number, 40 bit parent i_pos
+	 */
+	FILEID_FAT_WITH_PARENT = 0x72,
+
+	/*
 	 * Filesystems must not use 0xff file ID.
 	 */
 	FILEID_INVALID = 0xff,