[PATCH 4.9 022/130] scsi: xen-scsifront: add error handling for xenbus_printf

Greg Kroah-Hartman
2018-08-23T08:07:44Z

From: Zhouyang Jia <jiazhouyang09@gmail.com>

[ Upstream commit 93efbd39870474cc536b9caf4a6efeb03b0bc56f ]

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>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/xen-scsifront.c | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)

--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -676,10 +676,17 @@ static int scsifront_dev_reset_handler(s
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) {
+ xenbus_dev_error(info->dev, err,
+ "%s: writing dev_state_path", __func__);
+ return err;
+ }
+ }

return 0;
}
@@ -687,10 +694,15 @@ static int scsifront_sdev_configure(stru
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)
+ xenbus_dev_error(info->dev, err,
+ "%s: writing dev_state_path", __func__);
+ }
}

static struct scsi_host_template scsifront_sht = {
@@ -1025,9 +1037,12 @@ static void scsifront_do_lun_hotplug(str

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)
+ xenbus_dev_error(dev, err,
+ "%s: writing dev_state_path", __func__);
}
break;
case VSCSIFRONT_OP_DEL_LUN:
@@ -1041,10 +1056,14 @@ static void scsifront_do_lun_hotplug(str
}
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)
+ xenbus_dev_error(dev, err,
+ "%s: writing dev_state_path", __func__);
+ }
break;
default:
break;