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From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     hch@infradead.org
Cc:     rpeterso@redhat.com, agruenba@redhat.com, cluster-devel@redhat.com,
        linux-kernel@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: Re: [Cluster-devel] [PATCH] gfs2: Add check for mempool_alloc
Date:   Fri,  1 Apr 2022 11:37:55 +0800
Message-Id: <20220401033755.1892644-1-jiasheng@iscas.ac.cn>
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On Wed, 30 Mar 2022 11:56:41 +0800 Christoph Hellwig wrote:
>> As the potential failure of mempool_alloc(),
>> it could return NULL pointer.
>> Therefore, it should be better to check it
>> in order to avoid the dereference of the NULL
>> pointer.
>> 
>> Fixes: e8c92ed76900 ("GFS2: Clean up log write code path")
>> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> 
> Please explain how it could fail to start with.

I think that for safety, the cost of redundant and harmless
check is acceptable.
Also, checking after allocation is a good program pattern.
Therefore, it should be better to check it although it is
hard to fail.

Thanks,
Jiang