From: Theodore Ts'o <tytso@mit.edu>
To: Zheng Liu <gnehzuil.liu@gmail.com>
Cc: linux-ext4@vger.kernel.org, Jan kara <jack@suse.cz>,
Zheng Liu <wenqing.lz@taobao.com>
Subject: Re: [PATCH 6/7 v2] ext4: lookup block mapping in extent status tree
Date: Thu, 17 Jan 2013 23:00:06 -0500 [thread overview]
Message-ID: <20130118040006.GB13785@thunk.org> (raw)
In-Reply-To: <1357901627-3068-7-git-send-email-wenqing.lz@taobao.com>
On Fri, Jan 11, 2013 at 06:53:46PM +0800, Zheng Liu wrote:
> From: Zheng Liu <wenqing.lz@taobao.com>
>
> After tracking all extent status, we already have a extent cache in memory.
> Every time we want to lookup a block mapping, we can first try to lookup it in
> extent status tree to avoid a potential disk I/O.
>
> A new function called ext4_es_lookup_extent is defined to finish this work.
> When we try to lookup a block mapping, we always call ext4_map_blocks and/or
> ext4_da_map_blocks. So in these functions we first try to lookup a block
> mapping in extent status tree.
>
> CC: Jan kara <jack@suse.cz>
> CC: "Theodore Ts'o" <tytso@mit.edu>
> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Once we apply this this patch, we should be able to remove the the
single-entry extent cache in fs/ext4/extents.c ---
ext4_ext_put_in_cache(), ext4_ext_put_gap_in_cache(),
ext4_ext_in_cache() --- since the extent status tree makes this code
redundant (and will do a better job). This would be a good follow up,
cleanup patch.
- Ted
next prev parent reply other threads:[~2013-01-18 4:00 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-11 10:53 [PATCH 0/7 v2] ext4: extent status tree (step2) Zheng Liu
2013-01-11 10:53 ` [PATCH 1/7 v2] ext4: refine extent status tree Zheng Liu
2013-01-23 4:20 ` Theodore Ts'o
2013-01-11 10:53 ` [PATCH 2/7 v2] ext4: remove EXT4_MAP_FROM_CLUSTER flag Zheng Liu
2013-01-11 10:53 ` [PATCH 3/7 v2] ext4: add physical block and status member into extent status tree Zheng Liu
2013-01-17 4:42 ` Theodore Ts'o
2013-01-18 9:49 ` Zheng Liu
2013-01-11 10:53 ` [PATCH 4/7 v2] ext4: adjust interfaces of " Zheng Liu
2013-01-11 10:53 ` [PATCH 5/7 v2] ext4: track all extent status in " Zheng Liu
2013-01-23 4:31 ` Theodore Ts'o
2013-01-11 10:53 ` [PATCH 6/7 v2] ext4: lookup block mapping " Zheng Liu
2013-01-18 4:00 ` Theodore Ts'o [this message]
2013-01-18 9:52 ` Zheng Liu
2013-01-11 10:53 ` [PATCH 7/7 v2] ext4: reclaim extents from " Zheng Liu
2013-01-18 5:19 ` Theodore Ts'o
2013-01-18 5:39 ` Theodore Ts'o
2013-01-21 7:24 ` Zheng Liu
2013-01-21 15:00 ` Theodore Ts'o
2013-01-21 17:09 ` Zheng Liu
2013-01-23 6:06 ` [PATCH] fs: allow for fs-specific objects to be pruned as part of pruning inodes Theodore Ts'o
2013-01-23 10:52 ` Jan Kara
2013-01-23 13:06 ` Carlos Maiolino
2013-01-23 13:32 ` Dave Chinner
2013-01-23 16:34 ` Theodore Ts'o
2013-01-23 23:35 ` Dave Chinner
2013-01-24 8:58 ` Andrew Morton
2013-01-24 20:03 ` Dave Chinner
2013-01-21 14:43 ` [PATCH 7/7 v2] ext4: reclaim extents from extent status tree Jan Kara
2013-01-21 15:12 ` Zheng Liu
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=20130118040006.GB13785@thunk.org \
--to=tytso@mit.edu \
--cc=gnehzuil.liu@gmail.com \
--cc=jack@suse.cz \
--cc=linux-ext4@vger.kernel.org \
--cc=wenqing.lz@taobao.com \
/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).