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 <wangzh...@hisilicon.com> --- 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 b063410..d4181c8 100644 --- a/lib/sg_split.c +++ b/lib/sg_split.c @@ -178,11 +178,13 @@ 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