linux-ext4 - Re: [RFC PATCH 3/3] ext4: prevent partial update of the extent blocks

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Message-ID: <YV8kFRAlPWIxBK+1@mit.edu>
Date:   Thu, 7 Oct 2021 12:45:09 -0400
From:   "Theodore Ts'o" <tytso@....edu>
To:     Zhang Yi <yi.zhang@...wei.com>
Cc:     linux-ext4@...r.kernel.org, adilger.kernel@...ger.ca, jack@...e.cz,
        yukuai3@...wei.com
Subject: Re: [RFC PATCH 3/3] ext4: prevent partial update of the extent blocks

On Wed, Sep 08, 2021 at 08:08:50PM +0800, Zhang Yi wrote:
> In the most error path of current extents updating operations are not
> roll back partial updates properly when some bad things happens(.e.g in
> ext4_ext_insert_extent()). So we may get an inconsistent extents tree
> if journal has been aborted due to IO error, which may probability lead
> to BUGON later when we accessing these extent entries in errors=continue
> mode. This patch drop extent buffer's verify flag before updatng the
> contents in ext4_ext_get_access(), and reset it after updating in
> __ext4_ext_dirty(). After this patch we could force to check the extent
> buffer if extents tree updating was break off, make sure the extents are
> consistent.
> 
> Signed-off-by: Zhang Yi <yi.zhang@...wei.com>

Looks good, thanks

Reviewed-by: Theodore Ts'o <tytso@....edu>

						- Ted