[9/9] Xen / PCI: Use global PCI rescan-remove locking
diff mbox series

Message ID 2217895.SUZgMb7DfC@vostro.rjw.lan
State New, archived
Headers show
Series
  • PCI: Eliminate race conditions between hotplug and sysfs rescan/remove (Was: Re: [PATCH v2 04/10] PCI: Destroy pci dev only once)
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Commit Message

Rafael J. Wysocki Jan. 10, 2014, 2:29 p.m. UTC
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Multiple race conditions are possible between the Xen pcifront
device addition and removal and the generic PCI device addition
and removal that can be triggered via sysfs.

To avoid those race conditions make the Xen pcifront code use global
PCI rescan-remove locking.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/pci/xen-pcifront.c |    8 ++++++++
 1 file changed, 8 insertions(+)


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Patch
diff mbox series

Index: linux-pm/drivers/pci/xen-pcifront.c
===================================================================
--- linux-pm.orig/drivers/pci/xen-pcifront.c
+++ linux-pm/drivers/pci/xen-pcifront.c
@@ -471,12 +471,15 @@  static int pcifront_scan_root(struct pci
 	}
 	pcifront_init_sd(sd, domain, bus, pdev);
 
+	pci_lock_rescan_remove();
+
 	b = pci_scan_bus_parented(&pdev->xdev->dev, bus,
 				  &pcifront_bus_ops, sd);
 	if (!b) {
 		dev_err(&pdev->xdev->dev,
 			"Error creating PCI Frontend Bus!\n");
 		err = -ENOMEM;
+		pci_unlock_rescan_remove();
 		goto err_out;
 	}
 
@@ -494,6 +497,7 @@  static int pcifront_scan_root(struct pci
 	/* Create SysFS and notify udev of the devices. Aka: "going live" */
 	pci_bus_add_devices(b);
 
+	pci_unlock_rescan_remove();
 	return err;
 
 err_out:
@@ -556,6 +560,7 @@  static void pcifront_free_roots(struct p
 
 	dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
 
+	pci_lock_rescan_remove();
 	list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
 		list_del(&bus_entry->list);
 
@@ -568,6 +573,7 @@  static void pcifront_free_roots(struct p
 
 		kfree(bus_entry);
 	}
+	pci_unlock_rescan_remove();
 }
 
 static pci_ers_result_t pcifront_common_process(int cmd,
@@ -1043,8 +1049,10 @@  static int pcifront_detach_devices(struc
 				domain, bus, slot, func);
 			continue;
 		}
+		pci_lock_rescan_remove();
 		pci_stop_and_remove_bus_device(pci_dev);
 		pci_dev_put(pci_dev);
+		pci_unlock_rescan_remove();
 
 		dev_dbg(&pdev->xdev->dev,
 			"PCI device %04x:%02x:%02x.%d removed.\n",