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

From: Zhou Wang
Date: Thu Apr 18 2019 - 06:00:32 EST


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@xxxxxxxxxxxxx>
---
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