From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B91B8C76188 for ; Sun, 21 Jul 2019 04:07:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79DC52084C for ; Sun, 21 Jul 2019 04:07:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725904AbfGUEHB (ORCPT ); Sun, 21 Jul 2019 00:07:01 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:58104 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725535AbfGUEHB (ORCPT ); Sun, 21 Jul 2019 00:07:01 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92 #3 (Red Hat Linux)) id 1hp36f-000820-UA; Sun, 21 Jul 2019 04:06:06 +0000 Date: Sun, 21 Jul 2019 05:05:53 +0100 From: Al Viro To: Gao Xiang Cc: Gao Xiang , devel@driverdev.osuosl.org, Theodore Ts'o , Greg Kroah-Hartman , Miao Xie , linux-erofs@lists.ozlabs.org, LKML , linux-fsdevel@vger.kernel.org, Andrew Morton , Linus Torvalds Subject: Re: [PATCH v2 03/24] erofs: add super block operations Message-ID: <20190721040547.GF17978@ZenIV.linux.org.uk> References: <20190711145755.33908-1-gaoxiang25@huawei.com> <20190711145755.33908-4-gaoxiang25@huawei.com> <20190720224955.GD17978@ZenIV.linux.org.uk> <161cffc4-1d61-5dc6-45df-f1779ef03b0f@aol.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <161cffc4-1d61-5dc6-45df-f1779ef03b0f@aol.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 21, 2019 at 11:08:42AM +0800, Gao Xiang wrote: > It is for debugging use as you said below, mainly for our internal > testers whose jobs are > to read kmsg logs and catch kernel problems. sb->s_id (device number) > maybe not > straight-forward for them compared with dev_name... Huh? ->s_id is something like "sdb7" - it's bdev_name(), not a device number... > The initial purpose of erofs_mount_private was to passing multi private > data from erofs_mount > to erofs_read_super, which was written before fs_contest was introduced. That has nothing to do with fs_context (well, other than fs_context conversions affecting the code very close to that). > I agree with you, it seems better to just use s_id in community and > delete erofs_mount_private stuffs... > Yet I don't look into how to use new fs_context, could I keep using > legacy mount interface and fix them all? Sure. > I guess if I don't misunderstand, that is another suggestion -- in > short, leave all destructors to .kill_sb() and > cleanup fill_super(). Just be careful with that iput() there - AFAICS, if fs went live (i.e. if ->s_root is non-NULL), you really need it done only from put_super(); OTOH, for the case of NULL ->s_root ->put_super() won't be called at all, so in that case you need it directly in ->kill_sb().