linux-kernel - Re: [PATCH 0/7] ext4: Convert truncated extent data to inline data.

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Message-ID: <CAHB1NajUaauYPBwOLt7QktbUGrONBHZpifGy50u77y0Gcom+cw@mail.gmail.com>
Date: Tue, 7 Jan 2025 14:03:39 +0800
From: Julian Sun <sunjunchao2870@...il.com>
To: Jan Kara <jack@...e.cz>
Cc: linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org, tytso@....edu, 
	adilger.kernel@...ger.ca, boyu.mt@...bao.com, tm@....ma
Subject: Re: [PATCH 0/7] ext4: Convert truncated extent data to inline data.

Jan Kara <jack@...e.cz> 于2025年1月6日周一 23:51写道：
>
> On Fri 20-12-24 23:16:18, Julian Sun wrote:
> > Ext4 provides the feature of storing data inline and automatically
> > converts it to extent data when appropriate. However, files stored
> > as extents cannot be converted back to inline data after truncation,
> > even if the file size allows for inline data storage.
> > This patch set implements the feature to store large truncated files
> > as inline data when suitable, improving disk utilization.
> > Patches 1-3 include some cleanups and fixes.
> > Patches 4-6 refactor the functions responsible for writing inline data,
> > consolidating their logic for better code organization.
> > Patch 7 implements the feature of storing truncated files as inline data
> > on the next write operation.
>
> Thanks for the patches! So ext4 inline data feature is a bit problematic
> and has some locking issues in the implementation which we didn't manage to
> fix [1]. We are even considering just disabling this feature due to the
> complications with it. Hence I don't quite like further complicating this
> code by adding possibility to create inline data in an inode after it had
> data blocks allocated. That being said I like the preparatory cleanups in
> this patch series. These are useful regardless of the feature itself.

Ok. It looks fine to me. Thank you for your clarification.
>
>                                                                 Honza
>
> [1] See our attempts in thread:
> https://lore.kernel.org/all/d704ce55-321a-9c1d-1f8b-3360a0fdf978@huawei.com
>
> --
> Jan Kara <jack@...e.com>
> SUSE Labs, CR


Thanks,
-- 
Julian Sun <sunjunchao2870@...il.com>