vfs: Add open by file handle support

[AV: duplicate of open() guts removed; file_open_root() used instead]

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/internal.h b/fs/internal.h
index 52abc52..f3d15de 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -117,6 +117,9 @@
 extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
 		const char *, const struct open_flags *, int lookup_flags);
 
+extern long do_handle_open(int mountdirfd,
+			   struct file_handle __user *ufh, int open_flag);
+
 /*
  * inode.c
  */