Re: [PATCH V3] fnic: check pci_map_single() return value

Tomas Henzl
2015-09-21T14:19:03Z

On 12.8.2015 17:00, Maurizio Lombardi wrote:
> the kernel prints some warnings when compiled with CONFIG_DMA_API_DEBUG.
> This is because the fnic driver doesn't check the return value of
> pci_map_single().
>
> [ 11.942770] scsi host12: fnic
> [ 11.950811] ------------[ cut here ]------------
> [ 11.950818] WARNING: at lib/dma-debug.c:937 check_unmap+0x47b/0x920()
> [ 11.950821] fnic 0000:0c:00.0: DMA-API: device driver failed to check map error[device address=0x0000002020a30040] [size=44 bytes] [mapped as single]
>
> Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
> ---
> drivers/scsi/fnic/fnic_fcs.c | 46 +++++++++++++++++++++++++++++++++++--------
> drivers/scsi/fnic/fnic_scsi.c | 16 +++++++++++++++
> 2 files changed, 54 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/scsi/fnic/fnic_fcs.c b/drivers/scsi/fnic/fnic_fcs.c
> index bf0bbd4..67669a9 100644
> --- a/drivers/scsi/fnic/fnic_fcs.c
> +++ b/drivers/scsi/fnic/fnic_fcs.c
> @@ -939,6 +939,7 @@ int fnic_alloc_rq_frame(struct vnic_rq *rq)
> struct sk_buff *skb;
> u16 len;
> dma_addr_t pa;
> + int r;
>
> len = FC_FRAME_HEADROOM + FC_MAX_FRAME + FC_FRAME_TAILROOM;
> skb = dev_alloc_skb(len);
> @@ -952,8 +953,19 @@ int fnic_alloc_rq_frame(struct vnic_rq *rq)
> skb_reset_network_header(skb);
> skb_put(skb, len);
> pa = pci_map_single(fnic->pdev, skb->data, len, PCI_DMA_FROMDEVICE);
> +
> + r = pci_dma_mapping_error(fnic->pdev, pa);
> + if (r) {
> + printk(KERN_ERR "PCI mapping failed with error %d\n", r);
> + goto free_skb;
> + }
> +
> fnic_queue_rq_desc(rq, skb, pa, len);
> return 0;
> +
> +free_skb:
> + kfree_skb(skb);
> + return r;
> }
>
> void fnic_free_rq_buf(struct vnic_rq *rq, struct vnic_rq_buf *buf)
> @@ -981,6 +993,7 @@ void fnic_eth_send(struct fcoe_ctlr *fip, struct sk_buff *skb)
> struct ethhdr *eth_hdr;
> struct vlan_ethhdr *vlan_hdr;
> unsigned long flags;
> + int r;
>
> if (!fnic->vlan_hw_insert) {
> eth_hdr = (struct ethhdr *)skb_mac_header(skb);
> @@ -1003,18 +1016,27 @@ void fnic_eth_send(struct fcoe_ctlr *fip, struct sk_buff *skb)
>
> pa = pci_map_single(fnic->pdev, skb->data, skb->len, PCI_DMA_TODEVICE);
>
> - spin_lock_irqsave(&fnic->wq_lock[0], flags);
> - if (!vnic_wq_desc_avail(wq)) {
> - pci_unmap_single(fnic->pdev, pa, skb->len, PCI_DMA_TODEVICE);
> - spin_unlock_irqrestore(&fnic->wq_lock[0], flags);
> - kfree_skb(skb);
> - return;
> + r = pci_dma_mapping_error(fnic->pdev, pa);
> + if (r) {
> + printk(KERN_ERR "PCI mapping failed with error %d\n", r);
> + goto free_skb;
> }
>
> + spin_lock_irqsave(&fnic->wq_lock[0], flags);
> + if (!vnic_wq_desc_avail(wq))
> + goto irq_restore;
> +
> fnic_queue_wq_eth_desc(wq, skb, pa, skb->len,
> 0 /* hw inserts cos value */,
> fnic->vlan_id, 1);
> spin_unlock_irqrestore(&fnic->wq_lock[0], flags);
> + return;
> +
> +irq_restore:
> + spin_unlock_irqrestore(&fnic->wq_lock[0], flags);
> + pci_unmap_single(fnic->pdev, pa, skb->len, PCI_DMA_TODEVICE);
> +free_skb:
> + kfree_skb(skb);
> }
>
> /*
> @@ -1071,6 +1093,12 @@ static int fnic_send_frame(struct fnic *fnic, struct fc_frame *fp)
>
> pa = pci_map_single(fnic->pdev, eth_hdr, tot_len, PCI_DMA_TODEVICE);
>
> + ret = pci_dma_mapping_error(fnic->pdev, pa);
> + if (ret) {
> + printk(KERN_ERR "DMA map failed with error %d\n", ret);
> + goto free_skb_on_err;
> + }
> +
> if ((fnic_fc_trace_set_data(fnic->lport->host->host_no, FNIC_FC_SEND,
> (char *)eth_hdr, tot_len)) != 0) {
> printk(KERN_ERR "fnic ctlr frame trace error!!!");
> @@ -1082,15 +1110,17 @@ static int fnic_send_frame(struct fnic *fnic, struct fc_frame *fp)
> pci_unmap_single(fnic->pdev, pa,
> tot_len, PCI_DMA_TODEVICE);
> ret = -1;
> - goto fnic_send_frame_end;
> + goto irq_restore;
> }
>
> fnic_queue_wq_desc(wq, skb, pa, tot_len, fr_eof(fp),
> 0 /* hw inserts cos value */,
> fnic->vlan_id, 1, 1, 1);
> -fnic_send_frame_end:
> +
> +irq_restore:
> spin_unlock_irqrestore(&fnic->wq_lock[0], flags);
>
> +free_skb_on_err:
> if (ret)
> dev_kfree_skb_any(fp_skb(fp));
>
> diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
> index 155b286..2949d17 100644
> --- a/drivers/scsi/fnic/fnic_scsi.c
> +++ b/drivers/scsi/fnic/fnic_scsi.c
> @@ -330,6 +330,7 @@ static inline int fnic_queue_wq_copy_desc(struct fnic *fnic,
> int flags;
> u8 exch_flags;
> struct scsi_lun fc_lun;
> + int r;
>
> if (sg_count) {
> /* For each SGE, create a device desc entry */
> @@ -346,6 +347,12 @@ static inline int fnic_queue_wq_copy_desc(struct fnic *fnic,
> io_req->sgl_list,
> sizeof(io_req->sgl_list[0]) * sg_count,
> PCI_DMA_TODEVICE);
> +
> + r = pci_dma_mapping_error(fnic->pdev, io_req->sgl_list_pa);
> + if (r) {
> + printk(KERN_ERR "PCI mapping failed with error %d\n", r);
> + return SCSI_MLQUEUE_HOST_BUSY;
> + }
> }
>
> io_req->sense_buf_pa = pci_map_single(fnic->pdev,
> @@ -353,6 +360,15 @@ static inline int fnic_queue_wq_copy_desc(struct fnic *fnic,
> SCSI_SENSE_BUFFERSIZE,
> PCI_DMA_FROMDEVICE);
>
> + r = pci_dma_mapping_error(fnic->pdev, io_req->sense_buf_pa);
> + if (r) {
> + pci_unmap_single(fnic->pdev, io_req->sgl_list_pa,
> + sizeof(io_req->sgl_list[0]) * sg_count,
> + PCI_DMA_TODEVICE);
> + printk(KERN_ERR "PCI mapping failed with error %d\n", r);
> + return SCSI_MLQUEUE_HOST_BUSY;
> + }
> +
> int_to_scsilun(sc->device->lun, &fc_lun);
>
> /* Enqueue the descriptor in the Copy WQ */

Looks good,
Reviewed By: Tomas Henzl <thenzl@redhat.com>