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Subject: Re: [PATCH v2] ubi: gluebi: Fix NULL pointer dereference caused by
 ftl notifier
To:     Richard Weinberger <richard@nod.at>
CC:     ZhaoLong Wang <wangzhaolong1@huawei.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
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        yangerkun <yangerkun@huawei.com>
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From:   Zhihao Cheng <chengzhihao1@huawei.com>
Message-ID: <12400272-4449-040c-1ccd-6494a67f4da0@huawei.com>
Date:   Mon, 23 Oct 2023 15:36:29 +0800
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在 2023/10/23 15:15, Richard Weinberger 写道:
> ----- Ursprüngliche Mail -----
>> Von: "chengzhihao1" <chengzhihao1@huawei.com>
>>>> If we add new ioctls to control creation/destroying of gluebi, then
>>>> gluebi mtd won't be automatically created when UBI volume is added. I'm
>>>> not certain whether this change will effect existing startup process
>>>> that depends on gluebi.
>>> Let's take a stack back. The sole purpose of gluebi is providing
>>> a way to run JFFS2 on top of UBI.
>> Is it possible that someone runs ext4 on mtdblock based on gluebi, for
>> the advantage of wear-leveling?
> Unless they want to kill their NAND immediately, no.
> UBIblock hat initially an RW-Mode but it was rejected because
> UBI is not an FTL and will all dangerous setups.
>
> What I'm trying to say is, I'd like to avoid adding complicated solutions
> or workarounds just to make artificial stacking of outdated MTD components
> possible.
> Let's keep the big picture in mind.

Makes sense. Zhaolong and I didn't make clear the boundary between FTL 
and ubiblock/gluebi. Now, I believe that UBI needn't be responsible much 
for the extension mechanism(eg. mtdblock based on gluebi). So, let's 
pick your solution.

> Thanks,
> //richard
>
> .