[PATCH 4.9 078/104] PCI: Create SR-IOV virtfn/physfn links before attaching driver

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stuart Hayes <stuart.w.hayes@xxxxxxxxx>


[ Upstream commit 27d6162944b9b34c32cd5841acd21786637ee743 ]

When creating virtual functions, create the "virtfn%u" and "physfn" links
in sysfs *before* attaching the driver instead of after.  When we attach
the driver to the new virtual network interface first, there is a race when
the driver attaches to the new sends out an "add" udev event, and the
network interface naming software (biosdevname or systemd, for example)
tries to look at these links.

Signed-off-by: Stuart Hayes <stuart.w.hayes@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/pci/iov.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -164,7 +164,6 @@ int pci_iov_add_virtfn(struct pci_dev *d
 	pci_device_add(virtfn, virtfn->bus);
 	mutex_unlock(&iov->dev->sriov->lock);
 
-	pci_bus_add_device(virtfn);
 	sprintf(buf, "virtfn%u", id);
 	rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 	if (rc)
@@ -175,6 +174,8 @@ int pci_iov_add_virtfn(struct pci_dev *d
 
 	kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
 
+	pci_bus_add_device(virtfn);
+
 	return 0;
 
 failed2: