From 013be03840c2ba3a2717f9cee457f01fdc4d8436 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 18 Jun 2019 09:37:51 +0800 Subject: scsi: s390: zfcp_fc: use sg helper to iterate over scatterlist Unlike the legacy I/O path, scsi-mq preallocates a large array to hold the scatterlist for each request. This static allocation can consume substantial amounts of memory on modern controllers which support a large number of concurrently outstanding requests. To facilitate a switch to a smaller static allocation combined with a dynamic allocation for requests that need it, we need to make sure all SCSI drivers handle chained scatterlists correctly. Convert remaining drivers that directly dereference the scatterlist array to using the iterator functions. [mkp: clarified commit message] Cc: Steffen Maier Cc: Benjamin Block Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: linux-s390@vger.kernel.org Acked-by: Benjamin Block Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- drivers/s390/scsi/zfcp_fc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/s390') 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); -- cgit v1.2.3