From: Tao Ma <tm@tao.ma>
To: Andreas Dilger <adilger@whamcloud.com>
Cc: Theodore Ts'o <tytso@mit.edu>,
ext4 development <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH 01/02] ext2: reserve INCOMPAT_INLINEDATA feature flag
Date: Wed, 07 Dec 2011 09:43:46 +0800 [thread overview]
Message-ID: <4EDEC4D2.7080100@tao.ma> (raw)
In-Reply-To: <E8BB5200-9BE3-49FE-AFC2-18B2E7BBA5A8@whamcloud.com>
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 <adilger@whamcloud.com>
> Originally-by: Tao Ma <tm@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| \
next prev parent reply other threads:[~2011-12-07 1:43 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-07 0:05 [PATCH 00/02] ext2: Reserve feature flags Andreas Dilger
2011-12-07 0:13 ` [PATCH 01/02] ext2: reserve INCOMPAT_INLINEDATA feature flag Andreas Dilger
2011-12-07 0:39 ` Darrick J. Wong
2011-12-07 9:45 ` Andreas Dilger
2011-12-07 10:14 ` Tao Ma
2011-12-07 1:43 ` Tao Ma [this message]
2011-12-07 0:16 ` [PATCH 02/02] ext2: reserve INCOMPAT_LARGEDIR " Andreas Dilger
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4EDEC4D2.7080100@tao.ma \
--to=tm@tao.ma \
--cc=adilger@whamcloud.com \
--cc=linux-ext4@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).