From: Ming Lei <ming.lei@redhat.com>
Date: Tue, 18 Jun 2019 09:37:44 +0800
Subject: [PATCH] scsi: lpfc: use sg helper to iterate over scatterlist
Git-commit: 46e8e475a160be5e31e99171b7c0c8a21eb4d6ad
Patch-Mainline: v5.3-rc1
References: bsc#1148308
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]
Reviewed by: Ewan D. Milne <emilne@redhat.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>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/lpfc/lpfc_nvmet.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c
index d74bfd264495..877d1fb92754 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.c
+++ b/drivers/scsi/lpfc/lpfc_nvmet.c
@@ -2662,8 +2662,7 @@ lpfc_nvmet_prep_fcp_wqe(struct lpfc_hba *phba,
nvmewqe->drvrTimeout = (phba->fc_ratov * 3) + LPFC_DRVR_TIMEOUT;
nvmewqe->context1 = ndlp;
- for (i = 0; i < rsp->sg_cnt; i++) {
- sgel = &rsp->sg[i];
+ for_each_sg(rsp->sg, sgel, rsp->sg_cnt, i) {
physaddr = sg_dma_address(sgel);
cnt = sg_dma_len(sgel);
sgl->addr_hi = putPaddrHigh(physaddr);
--
2.16.4