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

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

[Zhou Wang]

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;
-- 
2.8.1

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

[Zhou Wang]

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?

Many thanks,
Zhou

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

[Zhou Wang]

On 2019/7/29 9:44, 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?
> 
> Many thanks,
> Zhou
>

Anyone can help to take this fix?

Best,
Zhou

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

[Jens Axboe]

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

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

[Zhou Wang]

On 2019/8/8 21:40, Jens Axboe wrote:
> 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. 

Thanks a lot for taking this patch :)

>