From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Darrick J. Wong" Subject: Re: [PATCH v2 19/28] mke2fs: add inline_data support in mke2fs Date: Tue, 3 Dec 2013 21:26:08 -0800 Message-ID: <20131204052608.GO9535@birch.djwong.org> References: <1386072715-9869-1-git-send-email-wenqing.lz@taobao.com> <1386072715-9869-20-git-send-email-wenqing.lz@taobao.com> <20131203223026.GI9535@birch.djwong.org> <20131204032757.GB11238@gmail.com> <20131204040819.GM9535@birch.djwong.org> <20131204052150.GG20409@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-ext4@vger.kernel.org, "Theodore Ts'o" , Zheng Liu Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:20660 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751103Ab3LDFbQ (ORCPT ); Wed, 4 Dec 2013 00:31:16 -0500 Content-Disposition: inline In-Reply-To: <20131204052150.GG20409@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Dec 04, 2013 at 01:21:50PM +0800, Zheng Liu wrote: > On Tue, Dec 03, 2013 at 08:08:19PM -0800, Darrick J. Wong wrote: > > On Wed, Dec 04, 2013 at 11:27:57AM +0800, Zheng Liu wrote: > > > On Tue, Dec 03, 2013 at 02:30:26PM -0800, Darrick J. Wong wrote: > > > [...] > > > > > + * notify users that inline data will never be useful. > > > > > + */ > > > > > + if ((fs_param.s_feature_incompat & > > > > > + EXT4_FEATURE_INCOMPAT_INLINE_DATA) && > > > > > + inode_size == EXT2_GOOD_OLD_INODE_SIZE) { > > > > > > > > Perhaps I'm missing something here, but why is it impossible to use i_blocks > > > > for inline data even if there's no space for EAs? > > > > > > If I understand correctly, on kernel side, we determine an inode has > > > inline data according to whether we have 'system.data' xattr entry on > > > inode extended attribute space. If an inode doesn't have enough space > > > to store an entry with 'system.data', we just think this inode doesn't > > > has inline data. So that is why I add this sanity check. > > > > Ok. I was curious. Small inode => no inline data seems like an unfortunate > > restriction to me, but oh well, it's your feature. I don't plan to go back to > > 128 byte inodes ever. :) > > > > Also, we could store four more bytes if we created a new e_name_index value (5? > > 9?) to represent "system.data". Any thoughts about that? > > Sorry, I don't get your point. Do you want to create a new e_name_index? > Any reason lets you want to do this? Yep, that's exactly what I propose to do, so we can cram four more bytes into the inline data. --D > > - Zheng > > > > > --D > > > > > > > > Regards, > > > - Zheng > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > > > the body of a message to majordomo@vger.kernel.org > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html