tree 9d08139b53727f300a80b592bfae5e931634b6f8
parent d3a78d8bf759d8848339dcc367c4c1678b57a08b
author Long Li <longli@microsoft.com> 1490306312 -0700
committer Bjorn Helgaas <bhelgaas@google.com> 1490367296 -0500

PCI: hv: Lock PCI bus on device eject

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 potentially
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().

Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>