[libata] restore sg on DMA mapping failure

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index e1346cd..1c1a7ca 100644 (file)
--- 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);