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Subject: Re: [PATCH 2/3] erofs: use LZ4_decompress_safe() for full decoding
To:     Gao Xiang <gaoxiang25@huawei.com>, <linux-erofs@lists.ozlabs.org>
CC:     LKML <linux-kernel@vger.kernel.org>, Miao Xie <miaoxie@huawei.com>,
        "Lasse Collin" <lasse.collin@tukaani.org>
References: <20200226023011.103798-1-gaoxiang25@huawei.com>
 <20200226023011.103798-2-gaoxiang25@huawei.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <8c1a119e-7f3d-a42d-3208-d30b476baf73@huawei.com>
Date:   Tue, 3 Mar 2020 17:49:54 +0800
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On 2020/2/26 10:30, Gao Xiang wrote:
> As Lasse pointed out, "EROFS uses LZ4_decompress_safe_partial
> for both partial and full blocks. Thus when it is decoding a
> full block, it doesn't know if the LZ4 decoder actually decoded
> all the input. The real uncompressed size could be bigger than
> the value stored in the file system metadata.
> 
> Using LZ4_decompress_safe instead of _safe_partial when
> decompressing a full block would help to detect errors."
> 
> So it's reasonable to use _safe in case of corrupted images and
> it might have some speed gain as well although I didn't observe
> much difference.
> 
> Cc: Lasse Collin <lasse.collin@tukaani.org>
> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,