From: Li Xi Subject: Re: [PATCH 0/4] quota: add project quota support Date: Fri, 1 Aug 2014 23:28:46 +0800 Message-ID: References: <20140801124015.GA5431@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Ext4 Developers List To: Jan Kara Return-path: Received: from mail-ie0-f172.google.com ([209.85.223.172]:55407 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750851AbaHAP2q (ORCPT ); Fri, 1 Aug 2014 11:28:46 -0400 Received: by mail-ie0-f172.google.com with SMTP id lx4so6141901iec.17 for ; Fri, 01 Aug 2014 08:28:46 -0700 (PDT) In-Reply-To: <20140801124015.GA5431@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2014-08-01 20:40 GMT+08:00 Jan Kara : > > 1) It should have been also posted to linux-fsdevel@vger.kernel.org, Al Viro > , Christoph Hellwig because > you are changing core VFS inode and infrastructure as well. For quota > changes you should have also CCed me as a quota maintainer. Sure. Thanks for reminding me. I will add these addresses next time. > > 2) I'm not convinced we actually want project ID in the core inode - so far > only XFS has this. For everyone else it's just extra bloat so we could just > put it in ext4_inode_info. Granted we'd need to somewhat change quota > interface so that it sees all the ids (uid, gid, projid) but they are > really needed in two places - dquot_initalize() and dquot_transfer() and > creating variants of these functions that just take an array of ids and use > them in ext4 is simple enough. OK, agreed. > > 3) I see no way how to get / set project ID from userspace. Did I miss > something? Yeah, you are right. I didn't push the interface patch. We implemeted two kinds of interfaces. One is based on extended attribute interfaces which simulate project ID as an extended attribute of the inode. The other implemented a new ioctl command for ext4. Personally, I think ioctl is better. What is your opinion? > > 4) The ext4 change is changing on-disk format. You definitely need a > feature flag for that so that kernels that don't understand project quotas > don't corrupt the filesystem. Also you need a support for this in > e2fsprogs. Sure. I will add feature flag for project quota of ext4. And there are quite some related tools need updates, including e2fsprogs and quota-tools. We will push those patches as soon as they are ready. > > 5) You make the feature configurable both in quota code and ext4. I don't > think the footprint of the feature warrants that. Sure. Good point. Thank you for the advices, I will refresh the patches and send the mails to all of the related addresses soon. Regards, Li Xi