PCI: Remove from bus_list and release resources in pci_release_dev()

Previously we removed the pci_dev from the bus_list and released its
resources in pci_destroy_dev().  But that's too early: it's possible to
call pci_destroy_dev() twice for the same device (e.g., via sysfs), and
that will cause an oops when we try to remove it from bus_list the second
time.

We should remove it from the bus_list only when the last reference to the
pci_dev has been released, i.e., in pci_release_dev().

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/probe.c

@@ -1154,6 +1154,18 @@ static void pci_release_capabilities(struct pci_dev *dev)
 	pci_free_cap_save_buffers(dev);
 }
 
+static void pci_free_resources(struct pci_dev *dev)
+{
+	int i;
+
+	pci_cleanup_rom(dev);
+	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+		struct resource *res = dev->resource + i;
+		if (res->parent)
+			release_resource(res);
+	}
+}
+
 /**
  * pci_release_dev - free a pci device structure when all users of it are finished.
  * @dev: device that's been disconnected
@@ -1163,9 +1175,14 @@ static void pci_release_capabilities(struct pci_dev *dev)
  */
 static void pci_release_dev(struct device *dev)
 {
-	struct pci_dev *pci_dev;
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+
+	down_write(&pci_bus_sem);
+	list_del(&pci_dev->bus_list);
+	up_write(&pci_bus_sem);
+
+	pci_free_resources(pci_dev);
 
-	pci_dev = to_pci_dev(dev);
 	pci_release_capabilities(pci_dev);
 	pci_release_of_node(pci_dev);
 	pcibios_release_device(pci_dev);

drivers/pci/remove.c

@@ -3,20 +3,6 @@
 #include <linux/pci-aspm.h>
 #include "pci.h"
 
-static void pci_free_resources(struct pci_dev *dev)
-{
-	int i;
-
-	msi_remove_pci_irq_vectors(dev);
-
-	pci_cleanup_rom(dev);
-	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
-		struct resource *res = dev->resource + i;
-		if (res->parent)
-			release_resource(res);
-	}
-}
-
 static void pci_stop_dev(struct pci_dev *dev)
 {
 	pci_pme_active(dev, false);
@@ -36,11 +22,6 @@ static void pci_destroy_dev(struct pci_dev *dev)
 {
 	device_del(&dev->dev);
 
-	down_write(&pci_bus_sem);
-	list_del(&dev->bus_list);
-	up_write(&pci_bus_sem);
-
-	pci_free_resources(dev);
 	put_device(&dev->dev);
 }