cifs: obtain file access during backup intent lookup (resend)

Rebased and resending the patch.

Path based queries can fail for lack of access, especially during lookup
during open.
open itself would actually succeed becasue of back up intent bit
but queries (either path or file handle based) do not have a means to
specifiy backup intent bit.
So query the file info during lookup using
 trans2 / findfirst / file_id_full_dir_info
to obtain file info as well as file_id/inode value.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index b0f4a42..f9b5d3d 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -151,7 +151,7 @@
 	}
 }
 
-static void
+void
 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 		       struct cifs_sb_info *cifs_sb)
 {