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

[Johannes Thumshirn <jthumshirn@suse.de>]

Maurizio Lombardi <mlombard@redhat.com> writes:

> 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 from my side.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                           Storage
jthumshirn@suse.de                                 +49 911 74053 689
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