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 for linux-mtd@lists.infradead.org; Mon, 21 Dec 2015 07:48:18 +0000
Subject: Re: Corrupt Empty Space Error at Runtime
To: Sheng Yong <shengyong1@huawei.com>, Adam <aps337@gmail.com>
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From: Richard Weinberger <richard@nod.at>
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Date: Mon, 21 Dec 2015 08:47:47 +0100
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Hi!

Am 21.12.2015 um 02:42 schrieb Sheng Yong:
> We have met several empty space corruptions these days, since the ECC
> functionality of the NAND controller driver seems not work correctly.
> But we are still considering if there is any workaroud to let UBIFS
> check if the corruption occurs really in empty space. If it is, UBIFS
> should recover the LEB.
> 
> There are 2 conditions we may check:
> 1. the left space size is less than the min size of a node, it must be
>    empty space;
> 2. how many bits are fliped in left space, if they are less than 4 bits
>    (many NAND support 1~4 bits ECC), it should be in empty space;

Please consider fixing the driver first.
We also have patches for gpmi. Maybe we can find a common way
to fix this clearly within MTD without weakening UBIFS.

Thanks,
//richard