[libata] restore sg on DMA mapping failure

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index e1346cddd37f..1c1a7caf785e 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2622,8 +2622,11 @@ static int ata_sg_setup_one(struct ata_queued_cmd *qc)
 
         dma_address = dma_map_single(ap->host_set->dev, qc->buf_virt,
                                      sg->length, dir);
-        if (dma_mapping_error(dma_address))
+        if (dma_mapping_error(dma_address)) {
+                /* restore sg */
+                sg->length += qc->pad_len;
                 return -1;
+        }
 
         sg_dma_address(sg) = dma_address;
         sg_dma_len(sg) = sg->length;
@@ -2694,8 +2697,11 @@ static int ata_sg_setup(struct ata_queued_cmd *qc)
 
         dir = qc->dma_dir;
         n_elem = dma_map_sg(ap->host_set->dev, sg, qc->n_elem, dir);
-        if (n_elem < 1)
+        if (n_elem < 1) {
+                /* restore last sg */
+                lsg->length += qc->pad_len;
                 return -1;
+        }
 
         DPRINTK("%d sg elements mapped\n", n_elem);