Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753180AbaAJOQW (ORCPT ); Fri, 10 Jan 2014 09:16:22 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:51028 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752109AbaAJOQS (ORCPT ); Fri, 10 Jan 2014 09:16:18 -0500 From: "Rafael J. Wysocki" To: Bjorn Helgaas Cc: Yinghai Lu , "Rafael J. Wysocki" , Gu Zheng , Guo Chao , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Mika Westerberg , Myron Stowe , Benjamin Herrenschmidt , linux-scsi@vger.kernel.org, Matthew Garrett , Konrad Rzeszutek Wilk Subject: [PATCH 9/9] Xen / PCI: Use global PCI rescan-remove locking Date: Fri, 10 Jan 2014 15:29:19 +0100 Message-ID: <2217895.SUZgMb7DfC@vostro.rjw.lan> User-Agent: KMail/4.11.3 (Linux/3.13.0-rc6+; KDE/4.11.3; x86_64; ; ) In-Reply-To: <20440867.YaQfKrcfsQ@vostro.rjw.lan> References: <1385429290-25397-1-git-send-email-yinghai@kernel.org> <1992931.Zv6xBcN8V4@vostro.rjw.lan> <20440867.YaQfKrcfsQ@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki 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 --- drivers/pci/xen-pcifront.c | 8 ++++++++ 1 file changed, 8 insertions(+) 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", -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/