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Message-ID: <afa51f3e-5ac8-86bd-364e-f55706c40470@linux.alibaba.com>
Date:   Wed, 5 Jul 2023 15:55:45 +0800
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Subject: Re: [PATCH v2 2/2] erofs: boost negative xattr lookup with bloom
 filter
To:     Alexander Larsson <alexl@redhat.com>,
        Jingbo Xu <jefflexu@linux.alibaba.com>
Cc:     chao@kernel.org, huyue2@coolpad.com, linux-erofs@lists.ozlabs.org,
        linux-kernel@vger.kernel.org
References: <20230705070427.92579-1-jefflexu@linux.alibaba.com>
 <20230705070427.92579-3-jefflexu@linux.alibaba.com>
 <CAL7ro1GuPZE8ek=uvfHEqGFrbbt=NO1=oO8_B-dVBF9go=StSg@mail.gmail.com>
From:   Gao Xiang <hsiangkao@linux.alibaba.com>
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On 2023/7/5 15:44, Alexander Larsson wrote:
> On Wed, Jul 5, 2023 at 9:04 AM Jingbo Xu <jefflexu@linux.alibaba.com> wrote:

...

>> +       if (erofs_sb_has_xattr_filter(sbi)) {
> 
> As I said in my other mail. I would really like this to just always do
> the filter check. It should be safe as older fs:es have zero in place
> here, and doing this allows me to create composefs images with the
> bloom filters that also work with older kernels.

As my previous email, this flag is on-disk compatible which means old
unsupported kernels will just ignore this and go on mounting.

But this flag indicates a new on-disk feature in the image anyway,
users could know if an image uses the new feature rather than seek to
individual inodes.

Does it sound reasonable or some other consideration?

Thanks,
Gao Xiang