From: Jan Kara Subject: Re: [v8 2/5] ext4: adds project ID support Date: Fri, 9 Jan 2015 10:47:58 +0100 Message-ID: <20150109094758.GA2576@quack.suse.cz> References: <1418102548-5469-1-git-send-email-lixi@ddn.com> <1418102548-5469-3-git-send-email-lixi@ddn.com> <20150108082625.GA15339@quack.suse.cz> <2EE35986-B398-432E-92D4-EEF875381319@dilger.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , Li Xi , Linux Filesystem Development List , ext4 development , linux-api@vger.kernel.org, Theodore Ts'o , Al Viro , Christoph Hellwig , Dmitry Monakhov To: Andreas Dilger Return-path: Received: from cantor2.suse.de ([195.135.220.15]:59060 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932145AbbAIJsB (ORCPT ); Fri, 9 Jan 2015 04:48:01 -0500 Content-Disposition: inline In-Reply-To: <2EE35986-B398-432E-92D4-EEF875381319@dilger.ca> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu 08-01-15 15:20:21, Andreas Dilger wrote: > On Jan 8, 2015, at 1:26 AM, Jan Kara wrote: > > On Tue 09-12-14 13:22:25, Li Xi wrote: > >> This patch adds a new internal field of ext4 inode to save project > >> identifier. Also a new flag EXT4_INODE_PROJINHERIT is added for > >> inheriting project ID from parent directory. > > I have noticed one thing you apparently changed in v7 of the patch set. > > See below. > > > >> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > >> index 29c43e7..8bd1da9 100644 > >> --- a/fs/ext4/ext4.h > >> +++ b/fs/ext4/ext4.h > >> @@ -377,16 +377,18 @@ struct flex_groups { > >> #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */ > >> #define EXT4_EOFBLOCKS_FL 0x00400000 /* Blocks allocated beyond EOF */ > >> #define EXT4_INLINE_DATA_FL 0x10000000 /* Inode has inline data. */ > >> +#define EXT4_PROJINHERIT_FL FS_PROJINHERIT_FL /* Create with parents projid */ > > How did FS_PROJINHERIT_FL get here? There used to be 0x20000000 in older > > version of the patch set which is correct - this definition is defining > > ext4 on-disk format. As such it is an ext4 specific flag and should be > > definined to a fixed constant independed of any other filesystem. It seems > > you are somewhat mixing what is an on-disk format flag value and what is a > > flag value passed from userspace. These two may be different things and > > you need to convert between the values when getting / setting flags... > > Currently the EXT4_*_FL and FS_*_FL values are all identical, and there > is no reason to change that before it is actually needed. Since the > FS_PROJINHERIT_FL is used via chattr/lsattr from userspace, this value > must also be kept the same in the future to avoid API breakage, so there > is no reason to worry about incompatibilities. Agreed. I was somewhat worried about having on-disk flag defined through the external non-ext4 define but you are right that neither can really change once we ship a kernel with it. > See also the [v8 5/5] patch, which is changing the EXT4_*_FL values to > use FS_*_FL constants, where applicable, so that it is more clear that > these values need to be the same. OK, I've missed that. So if things will be consistent again, I'm fine with the change. Honza -- Jan Kara SUSE Labs, CR