GitLab

BugLink: http://bugs.launchpad.net/bugs/1665097



A PCI_EJECT message can arrive at the same time we are calling
pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS
message or in create_root_hv_pci_bus(), in this case we could potentailly
modify the bus from multiple places. Properly lock the bus access.

Thanks Dexuan Cui <decui@microsoft.com> for pointing out the race
condition in create_root_hv_pci_bus().
Signed-off-by: Long Li <longli@microsoft.com>
Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>