[PATCH 2/2] nvme-fc: Fix the error check for dma_map_sg

[Jack Wang]

dma_map_sg return 0 on error, add missing check.

Cc: James Smart <james.smart@xxxxxxxxxxxx>
Cc: Keith Busch <kbusch@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Cc: linux-nvme@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Fixes: e399441de911 ("nvme-fabrics: Add host support for FC transport")

Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxx>
---
 drivers/nvme/host/fc.c   | 2 +-
 drivers/nvme/target/fc.c | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 127abaf9ba5d..95050f2e0a06 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2616,7 +2616,7 @@ nvme_fc_map_data(struct nvme_fc_ctrl *ctrl, struct request *rq,
 	WARN_ON(op->nents > blk_rq_nr_phys_segments(rq));
 	freq->sg_cnt = fc_dma_map_sg(ctrl->lport->dev, freq->sg_table.sgl,
 				op->nents, rq_dma_dir(rq));
-	if (unlikely(freq->sg_cnt <= 0)) {
+	if (unlikely(!freq->sg_cnt)) {
 		sg_free_table_chained(&freq->sg_table, NVME_INLINE_SG_CNT);
 		freq->sg_cnt = 0;
 		return -EFAULT;
diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index ab2627e17bb9..3749ca28860b 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -2089,6 +2089,11 @@ nvmet_fc_alloc_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
 				((fod->io_dir == NVMET_FCP_WRITE) ?
 					DMA_FROM_DEVICE : DMA_TO_DEVICE));
 				/* note: write from initiator perspective */
+	if (!fod->data_sg_cnt) {
+		sgl_free(fod->data_sg);
+		fod->data_sg = NULL;
+		goto out;
+	}
 	fod->next_sg = fod->data_sg;
 
 	return 0;
-- 
2.34.1