ovl: encode pure upper file handles
Encode overlay file handles as struct ovl_fh containing the file handle
encoding of the real upper inode.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 2dddcd2..f2baa2c 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -68,6 +68,9 @@
#error Endianness not defined
#endif
+/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
+#define OVL_FILEID 0xfb
+
/* On-disk and in-memeory format for redirect by file handle */
struct ovl_fh {
u8 version; /* 0 */
@@ -351,3 +354,6 @@
struct ovl_fh *ovl_encode_fh(struct dentry *real, bool is_upper);
int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
struct dentry *upper);
+
+/* export.c */
+extern const struct export_operations ovl_export_operations;