[PATCH V5 10/16] s390: zfcp_fc: use sg helper to operate scatterlist

Ming Lei
2019-06-18T01:39:12Z

Use the scatterlist iterators and remove direct indexing of the
scatterlist array.

This way allows us to pre-allocate one small scatterlist, which can be
chained with one runtime allocated scatterlist if the pre-allocated one
isn't enough for the whole request.

Cc: Steffen Maier <maier@linux.ibm.com>
Cc: Benjamin Block <bblock@linux.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/s390/scsi/zfcp_fc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index 33eddb02ee30..b018b61bd168 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -620,7 +620,7 @@ static void zfcp_fc_sg_free_table(struct scatterlist *sg, int count)
{
int i;

- for (i = 0; i < count; i++, sg++)
+ for (i = 0; i < count; i++, sg = sg_next(sg))
if (sg)
free_page((unsigned long) sg_virt(sg));
else
@@ -641,7 +641,7 @@ static int zfcp_fc_sg_setup_table(struct scatterlist *sg, int count)
int i;

sg_init_table(sg, count);
- for (i = 0; i < count; i++, sg++) {
+ for (i = 0; i < count; i++, sg = sg_next(sg)) {
addr = (void *) get_zeroed_page(GFP_KERNEL);
if (!addr) {
zfcp_fc_sg_free_table(sg, i);
--
2.20.1