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

Maurizio Lombardi
2015-08-12T15:00:27Z

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 */
--
Maurizio Lombardi