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Subject: Re: [RFC PATCH 03/12] staging: android: ion: Duplicate sg_table
To: Hillf Danton <hillf.zj@alibaba-inc.com>,
        "'Sumit Semwal'" <sumit.semwal@linaro.org>,
        "'Riley Andrews'" <riandrews@android.com>, arve@android.com
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From: Laura Abbott <labbott@redhat.com>
Message-ID: <59f69b1b-0a10-01e9-3e64-387d8f123674@redhat.com>
Date: Fri, 3 Mar 2017 10:41:25 -0800
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On 03/03/2017 12:18 AM, Hillf Danton wrote:
> 
> On March 03, 2017 5:45 AM Laura Abbott wrote: 
>>
>> +static struct sg_table *dup_sg_table(struct sg_table *table)
>> +{
>> +	struct sg_table *new_table;
>> +	int ret, i;
>> +	struct scatterlist *sg, *new_sg;
>> +
>> +	new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);
>> +	if (!new_table)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	ret = sg_alloc_table(new_table, table->nents, GFP_KERNEL);
>> +	if (ret) {
>> +		kfree(table);
> 
> Free new table?
> 
>> +		return ERR_PTR(-ENOMEM);
>> +	}
>> +
>> +	new_sg = new_table->sgl;
>> +	for_each_sg(table->sgl, sg, table->nents, i) {
>> +		memcpy(new_sg, sg, sizeof(*sg));
>> +		sg->dma_address = 0;
>> +		new_sg = sg_next(new_sg);
>> +	}
>> +
> 
> Do we need a helper, sg_copy_table(dst_table, src_table)?
> 
>> +	return new_table;
>> +}
>> +

Yes, that would probably be good since I've seen this
code elsewhere.

Thanks,
Laura