exportfs: add FILEID_INVALID to indicate invalid fid_type

This commit adds FILEID_INVALID = 0xff in fid_type to
indicate invalid fid_type

It avoids using magic number 255

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
index 12291a7ee27..0e145254630 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -83,6 +83,11 @@ enum fid_type {
          * 64 bit parent inode number.
          */
         FILEID_NILFS_WITH_PARENT = 0x62,
+
+        /*
+         * Filesystems must not use 0xff file ID.
+         */
+        FILEID_INVALID = 0xff,
 };
 
 struct fid {