xen/pcifront: Process failure for pcifront_(re)scan_root()

When pcifront_try_connect() finds no PCI roots, it falls back to calling
pcifront_scan_root() for 0000:00.  If that fails, it used to switch to
XenbusStateConnected and return success (because xenbus_switch_state()
currently always succeeds).

If pcifront_scan_root() fails, leave the XenbusState unchanged and return
an error code.

Similarly, pcifront_attach_devices() falls back to calling
pcifront_rescan_root() for 0000:00.  If that fails, it used to switch to
XenbusStateConnected and return an error code.

If pcifront_rescan_root() fails, leave the XenbusState unchanged and return
the error code.

[bhelgaas: changelog]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 116ca3746adb..93316504f567 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)