don't open-code parent_ino() in assorted ->readdir()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ceph/dir.c

@@ -252,7 +252,7 @@ static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
 		off = 1;
 	}
 	if (filp->f_pos == 1) {
-		ino_t ino = filp->f_dentry->d_parent->d_inode->i_ino;
+		ino_t ino = parent_ino(filp->f_dentry);
 		dout("readdir off 1 -> '..'\n");
 		if (filldir(dirent, "..", 2, ceph_make_fpos(0, 1),
 			    ceph_translate_ino(inode->i_sb, ino),

fs/cifs/readdir.c

@@ -796,7 +796,7 @@ int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 		file->f_pos++;
 	case 1:
 		if (filldir(direntry, "..", 2, file->f_pos,
-		     file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
+		     parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 			cERROR(1, "Filldir for parent dir failed");
 			rc = -ENOMEM;
 			break;

fs/coda/dir.c

@@ -473,7 +473,7 @@ static int coda_venus_readdir(struct file *coda_file, void *buf,
 		coda_file->f_pos++;
 	}
 	if (coda_file->f_pos == 1) {
-		ret = filldir(buf, "..", 2, 1, de->d_parent->d_inode->i_ino, DT_DIR);
+		ret = filldir(buf, "..", 2, 1, parent_ino(de), DT_DIR);
 		if (ret < 0)
 			goto out;
 		result++;