From: Tao Ma Subject: Re: [PATCH 01/02] ext2: reserve INCOMPAT_INLINEDATA feature flag Date: Wed, 07 Dec 2011 09:43:46 +0800 Message-ID: <4EDEC4D2.7080100@tao.ma> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Theodore Ts'o , ext4 development To: Andreas Dilger Return-path: Received: from oproxy6-pub.bluehost.com ([67.222.54.6]:59625 "HELO oproxy6-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751744Ab1LGBnw (ORCPT ); Tue, 6 Dec 2011 20:43:52 -0500 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On 12/07/2011 08:13 AM, Andreas Dilger wrote: > Reserve the EXT4_FEATURE_INCOMPAT_INLINEDATA feature flag for use > with storing small file data in the i_blocks field (up to 60 bytes) > and/or the large xattr space (after i_extra_isize, up to the large > inode size). On typical filesystems this can save 1-3% of the space, > and more importantly it also avoids seeking to read the data block. > > This will become increasingly important with bigalloc filesystems, > since they consume a full cluster of blocks for each file, including > small directories that could easily fit into the inode itself. > > Signed-off-by: Andreas Dilger > Originally-by: Tao Ma I am fine with it. Thanks. Tao > --- > lib/ext2fs/ext2_fs.h | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h > index 0f8cde8..6cf47f9 100644 > --- a/lib/ext2fs/ext2_fs.h > +++ b/lib/ext2fs/ext2_fs.h > @@ -719,6 +719,7 @@ struct ext2_super_block { > #define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200 > #define EXT4_FEATURE_INCOMPAT_EA_INODE 0x0400 > #define EXT4_FEATURE_INCOMPAT_DIRDATA 0x1000 > +#define EXT4_FEATURE_INCOMPAT_INLINEDATA 0x2000 /* data in inode */ > > #define EXT2_FEATURE_COMPAT_SUPP 0 > #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \