Re: [PATCH resend v2] lib: scatterlist: Fix to support no mapped sg

[Jens Axboe <axboe@fb.com>]

On 7/28/19 6:44 PM, Zhou Wang wrote:
> On 2019/7/24 11:54, Zhou Wang wrote:
>> In function sg_split, the second sg_calculate_split will return -EINVAL
>> when in_mapped_nents is 0.
>>
>> Indeed there is no need to do second sg_calculate_split and sg_split_mapped
>> when in_mapped_nents is 0, as in_mapped_nents indicates no mapped entry in
>> original sgl.
>>
>> Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
>> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
>> ---
>> v2: Just add Acked-by from Robert.
>>
>>   lib/sg_split.c | 12 +++++++-----
>>   1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/lib/sg_split.c b/lib/sg_split.c
>> index 9982c63..60a0bab 100644
>> --- a/lib/sg_split.c
>> +++ b/lib/sg_split.c
>> @@ -176,11 +176,13 @@ int sg_split(struct scatterlist *in, const int in_mapped_nents,
>>   	 * The order of these 3 calls is important and should be kept.
>>   	 */
>>   	sg_split_phys(splitters, nb_splits);
>> -	ret = sg_calculate_split(in, in_mapped_nents, nb_splits, skip,
>> -				 split_sizes, splitters, true);
>> -	if (ret < 0)
>> -		goto err;
>> -	sg_split_mapped(splitters, nb_splits);
>> +	if (in_mapped_nents) {
>> +		ret = sg_calculate_split(in, in_mapped_nents, nb_splits, skip,
>> +					 split_sizes, splitters, true);
>> +		if (ret < 0)
>> +			goto err;
>> +		sg_split_mapped(splitters, nb_splits);
>> +	}
>>   
>>   	for (i = 0; i < nb_splits; i++) {
>>   		out[i] = splitters[i].out_sg;
>>
> 
> Hi Jens,
> 
> I saw you are the committer of sg_splite.c, could you help to take this patch?

Yes, I can take it for 5.4, it looks fine to me. 

-- 
Jens Axboe