From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Jiang Liu To: Bjorn Helgaas , Konrad Rzeszutek Wilk Cc: Jiang Liu , Don Dutile , Yinghai Lu , Kenji Kaneshige , Yijing Wang , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH 5/5] PCI/xen-pcifront: simplify code by hotplug safe pci_get_domain_bus_and_slot() Date: Tue, 28 Aug 2012 23:43:58 +0800 Message-Id: <1346168638-32724-6-git-send-email-jiang.liu@huawei.com> In-Reply-To: <1346168638-32724-1-git-send-email-jiang.liu@huawei.com> References: <1346168638-32724-1-git-send-email-jiang.liu@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 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 --- drivers/pci/xen-pcifront.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index d6cc62c..def8d0b 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -982,7 +982,6 @@ static int pcifront_detach_devices(struct pcifront_device *pdev) int err = 0; int i, num_devs; unsigned int domain, bus, slot, func; - struct pci_bus *pci_bus; struct pci_dev *pci_dev; char str[64]; @@ -1032,13 +1031,8 @@ static int pcifront_detach_devices(struct pcifront_device *pdev) goto out; } - pci_bus = pci_find_bus(domain, bus); - if (!pci_bus) { - dev_dbg(&pdev->xdev->dev, "Cannot get bus %04x:%02x\n", - domain, bus); - continue; - } - pci_dev = pci_get_slot(pci_bus, PCI_DEVFN(slot, func)); + pci_dev = pci_get_domain_bus_and_slot(domain, bus, + PCI_DEVFN(slot, func)); if (!pci_dev) { dev_dbg(&pdev->xdev->dev, "Cannot get PCI device %04x:%02x:%02x.%d\n", -- 1.7.9.5