lib: scatterlist: Fix to support no mapped sg

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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Zhou Wang 2019-07-24 11:54:23 +08:00 committed by Jens Axboe
parent ba6f7da99a
commit 79e178f438

View file

@ -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;