diff mbox

[v2] scsi: xen-scsifront: add error handling for xenbus_printf

Message ID 1528992514-53963-1-git-send-email-jiazhouyang09@gmail.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Zhouyang Jia June 14, 2018, 4:08 p.m. UTC 
When xenbus_printf fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling xenbus_printf.

Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
---
v1->v2:
- Fix dereferencing before checking
---
 drivers/scsi/xen-scsifront.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

Comments

Boris Ostrovsky June 14, 2018, 9:54 p.m. UTC | #1 
On 06/14/2018 12:08 PM, Zhouyang Jia wrote:
> When xenbus_printf fails, the lack of error-handling code may
> cause unexpected results.
>
> This patch adds error-handling code after calling xenbus_printf.
>
> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
> ---
> v1->v2:
> - Fix dereferencing before checking
> ---
>  drivers/scsi/xen-scsifront.c | 29 ++++++++++++++++++++++-------
>  1 file changed, 22 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
> index 36f59a1..a7f6111 100644
> --- a/drivers/scsi/xen-scsifront.c
> +++ b/drivers/scsi/xen-scsifront.c
> @@ -654,10 +654,16 @@ static int scsifront_dev_reset_handler(struct scsi_cmnd *sc)
>  static int scsifront_sdev_configure(struct scsi_device *sdev)
>  {
>  	struct vscsifrnt_info *info = shost_priv(sdev->host);
> +	int err;
>  
> -	if (info && current == info->curr)
> -		xenbus_printf(XBT_NIL, info->dev->nodename,
> +	if (info && current == info->curr) {
> +		err = xenbus_printf(XBT_NIL, info->dev->nodename,
>  			      info->dev_state_path, "%d", XenbusStateConnected);
> +		if (err) {
> +			dev_err(&info->dev->dev, "writing dev_state_path\n");

These errors should be reported using xenbus_dev_error().

And the second patch too.

-boris
diff mbox

Patch

diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index 36f59a1..a7f6111 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -654,10 +654,16 @@  static int scsifront_dev_reset_handler(struct scsi_cmnd *sc)
 static int scsifront_sdev_configure(struct scsi_device *sdev)
 {
 	struct vscsifrnt_info *info = shost_priv(sdev->host);
+	int err;
 
-	if (info && current == info->curr)
-		xenbus_printf(XBT_NIL, info->dev->nodename,
+	if (info && current == info->curr) {
+		err = xenbus_printf(XBT_NIL, info->dev->nodename,
 			      info->dev_state_path, "%d", XenbusStateConnected);
+		if (err) {
+			dev_err(&info->dev->dev, "writing dev_state_path\n");
+			return err;
+		}
+	}
 
 	return 0;
 }
@@ -665,10 +671,14 @@  static int scsifront_sdev_configure(struct scsi_device *sdev)
 static void scsifront_sdev_destroy(struct scsi_device *sdev)
 {
 	struct vscsifrnt_info *info = shost_priv(sdev->host);
+	int err;
 
-	if (info && current == info->curr)
-		xenbus_printf(XBT_NIL, info->dev->nodename,
+	if (info && current == info->curr) {
+		err = xenbus_printf(XBT_NIL, info->dev->nodename,
 			      info->dev_state_path, "%d", XenbusStateClosed);
+		if (err)
+			dev_err(&info->dev->dev, "writing dev_state_path\n");
+	}
 }
 
 static struct scsi_host_template scsifront_sht = {
@@ -1003,9 +1013,11 @@  static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
 
 			if (scsi_add_device(info->host, chn, tgt, lun)) {
 				dev_err(&dev->dev, "scsi_add_device\n");
-				xenbus_printf(XBT_NIL, dev->nodename,
+				err = xenbus_printf(XBT_NIL, dev->nodename,
 					      info->dev_state_path,
 					      "%d", XenbusStateClosed);
+				if (err)
+					dev_err(&dev->dev, "writing dev_state_path\n");
 			}
 			break;
 		case VSCSIFRONT_OP_DEL_LUN:
@@ -1019,10 +1031,13 @@  static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
 			}
 			break;
 		case VSCSIFRONT_OP_READD_LUN:
-			if (device_state == XenbusStateConnected)
-				xenbus_printf(XBT_NIL, dev->nodename,
+			if (device_state == XenbusStateConnected) {
+				err = xenbus_printf(XBT_NIL, dev->nodename,
 					      info->dev_state_path,
 					      "%d", XenbusStateConnected);
+				if (err)
+					dev_err(&dev->dev, "writing dev_state_path\n");
+			}
 			break;
 		default:
 			break;