[PATCH 4/5] PCI/IOV: simplify code by hotplug safe pci_get_domain_bus_and_slot()

[Jiang Liu <liuj97@gmail.com>]

Following code has a race window between pci_find_bus() and pci_get_slot()
if PCI hotplug operation happens between them which removes the pci_bus.
So use PCI hotplug safe interface pci_get_domain_bus_and_slot() instead,
which also reduces code complexity.

struct pci_bus *pci_bus = pci_find_bus(domain, busno);
struct pci_dev *pci_dev = pci_get_slot(pci_bus, devfn);

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
---
 drivers/pci/iov.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index aeccc91..b0fe771 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -152,15 +152,11 @@ failed1:
 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 {
 	char buf[VIRTFN_ID_LEN];
-	struct pci_bus *bus;
 	struct pci_dev *virtfn;
 	struct pci_sriov *iov = dev->sriov;
 
-	bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id));
-	if (!bus)
-		return;
-
-	virtfn = pci_get_slot(bus, virtfn_devfn(dev, id));
+	virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
+			virtfn_bus(dev, id), virtfn_devfn(dev, id));
 	if (!virtfn)
 		return;
 
-- 
1.7.9.5