[PATCH next] xen: pcifront: Process failure for pcifront_(re)scan_root()

[Chen Gang <gang.chen.5i5j@gmail.com>]

When pcifront_rescan_root() or pcifront_scan_root() fails, need return
error code, neither set XenbusStateConnected state, just like the other
areas have done.

For pcifront_rescan_root(), it will return error code ("num_roots = 0;",
skip xenbus_switch_state return value).

For pcifront_scan_root(), it will return 0 ("num_roots = 0;", set 0 by
the return value of xenbus_switch_state, which always return 0, at
present).

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 drivers/pci/xen-pcifront.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 53df39a..d78d884 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -866,6 +866,11 @@ static int pcifront_try_connect(struct pcifront_device *pdev)
 		xenbus_dev_error(pdev->xdev, err,
 				 "No PCI Roots found, trying 0000:00");
 		err = pcifront_scan_root(pdev, 0, 0);
+		if (err) {
+			xenbus_dev_fatal(pdev->xdev, err,
+					 "Error scanning PCI root 0000:00");
+			goto out;
+		}
 		num_roots = 0;
 	} else if (err != 1) {
 		if (err == 0)
@@ -947,6 +952,11 @@ static int pcifront_attach_devices(struct pcifront_device *pdev)
 		xenbus_dev_error(pdev->xdev, err,
 				 "No PCI Roots found, trying 0000:00");
 		err = pcifront_rescan_root(pdev, 0, 0);
+		if (err) {
+			xenbus_dev_fatal(pdev->xdev, err,
+					 "Error scanning PCI root 0000:00");
+			goto out;
+		}
 		num_roots = 0;
 	} else if (err != 1) {
 		if (err == 0)
-- 
1.9.3