PCI: hotplug: Use global PCI rescan-remove locking
Multiple race conditions are possible between PCI hotplug and the generic
PCI bus rescan and device removal that can be triggered via sysfs.
To avoid those race conditions make PCI hotplug use global PCI
rescan-remove locking.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index 1983551..b07d7cc 100644
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -39,22 +39,26 @@
struct pci_dev *dev;
struct pci_dev *bridge = p_slot->ctrl->pcie->port;
struct pci_bus *parent = bridge->subordinate;
- int num;
+ int num, ret = 0;
struct controller *ctrl = p_slot->ctrl;
+ pci_lock_rescan_remove();
+
dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
if (dev) {
ctrl_err(ctrl, "Device %s already exists "
"at %04x:%02x:00, cannot hot-add\n", pci_name(dev),
pci_domain_nr(parent), parent->number);
pci_dev_put(dev);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
if (num == 0) {
ctrl_err(ctrl, "No new device found\n");
- return -ENODEV;
+ ret = -ENODEV;
+ goto out;
}
list_for_each_entry(dev, &parent->devices, bus_list)
@@ -73,7 +77,9 @@
pci_bus_add_devices(parent);
- return 0;
+ out:
+ pci_unlock_rescan_remove();
+ return ret;
}
int pciehp_unconfigure_device(struct slot *p_slot)
@@ -90,6 +96,8 @@
__func__, pci_domain_nr(parent), parent->number);
pciehp_get_adapter_status(p_slot, &presence);
+ pci_lock_rescan_remove();
+
/*
* Stopping an SR-IOV PF device removes all the associated VFs,
* which will update the bus->devices list and confuse the
@@ -124,5 +132,6 @@
pci_dev_put(dev);
}
+ pci_unlock_rescan_remove();
return rc;
}