From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Yinghai Lu To: Bjorn Helgaas Cc: "Rafael J. Wysocki" , Gu Zheng , Guo Chao , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Yinghai Lu Subject: [PATCH v2 04/10] PCI: Destroy pci dev only once Date: Mon, 25 Nov 2013 17:28:04 -0800 Message-Id: <1385429290-25397-5-git-send-email-yinghai@kernel.org> In-Reply-To: <1385429290-25397-1-git-send-email-yinghai@kernel.org> References: <1385429290-25397-1-git-send-email-yinghai@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: Mutliple removing via /sys will call pci_destroy_dev two times. | When concurent removing pci devices which are in the same pci subtree | via sysfs, such as: | echo -n 1 > /sys/bus/pci/devices/0000\:10\:00.0/remove ; echo -n 1 > | /sys/bus/pci/devices/0000\:1a\:01.0/remove | (1a:01.0 device is downstream from the 10:00.0 bridge) | | the following warning will show: | [ 1799.280918] ------------[ cut here ]------------ | [ 1799.336199] WARNING: CPU: 7 PID: 126 at lib/list_debug.c:53 __list_del_entry+0x63/0xd0() | [ 1799.433093] list_del corruption, ffff8807b4a7c000->next is LIST_POISON1 (dead000000100100) | [ 1800.276623] CPU: 7 PID: 126 Comm: kworker/u512:1 Tainted: G W 3.12.0-rc5+ #196 | [ 1800.508918] Workqueue: sysfsd sysfs_schedule_callback_work | [ 1800.574703] 0000000000000009 ffff8807adbadbd8 ffffffff8168b26c ffff8807c27d08a8 | [ 1800.663860] ffff8807adbadc28 ffff8807adbadc18 ffffffff810711dc ffff8807adbadc68 | [ 1800.753130] ffff8807b4a7c000 ffff8807b4a7c000 ffff8807ad089c00 0000000000000000 | [ 1800.842282] Call Trace: | [ 1800.871651] [] dump_stack+0x55/0x76 | [ 1800.933301] [] warn_slowpath_common+0x8c/0xc0 | [ 1801.005283] [] warn_slowpath_fmt+0x46/0x50 | [ 1801.074081] [] __list_del_entry+0x63/0xd0 | [ 1801.141839] [] list_del+0x11/0x40 | [ 1801.201320] [] pci_remove_bus_device+0x6a/0xe0 | [ 1801.274279] [] pci_stop_and_remove_bus_device+0x1e/0x30 | [ 1801.356606] [] remove_callback+0x2b/0x40 | [ 1801.423412] [] sysfs_schedule_callback_work+0x18/0x60 | [ 1801.503744] [] process_one_work+0x1f5/0x540 | [ 1801.573640] [] ? process_one_work+0x193/0x540 | [ 1801.645616] [] worker_thread+0x11c/0x370 | [ 1801.712337] [] ? rescuer_thread+0x350/0x350 | [ 1801.782178] [] kthread+0xed/0x100 | [ 1801.841661] [] ? kthread_create_on_node+0x160/0x160 | [ 1801.919919] [] ret_from_fork+0x7c/0xb0 | [ 1801.984608] [] ? kthread_create_on_node+0x160/0x160 | [ 1802.062825] ---[ end trace d77f2054de000fb7 ]--- | | This issue is related to the bug 54411: | https://bugzilla.kernel.org/show_bug.cgi?id=54411 Add is_removed to record if pci_destroy_dev is called already. During second calling, still have extra dev ref hold via device_schedule_call, so we are safe to check dev->is_removed. It fixs the problem In Gu's test. -v2: add partial changelog from Gu Zheng refresh after patch of moving device_del from Rafael. Signed-off-by: Yinghai Lu --- drivers/pci/remove.c | 8 +++++--- include/linux/pci.h | 1 + 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index f452148..b090cec 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -20,9 +20,11 @@ static void pci_stop_dev(struct pci_dev *dev) static void pci_destroy_dev(struct pci_dev *dev) { - device_del(&dev->dev); - - put_device(&dev->dev); + if (!dev->is_removed) { + device_del(&dev->dev); + dev->is_removed = 1; + put_device(&dev->dev); + } } void pci_remove_bus(struct pci_bus *bus) diff --git a/include/linux/pci.h b/include/linux/pci.h index 1084a15..ccb316d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -321,6 +321,7 @@ struct pci_dev { unsigned int multifunction:1;/* Part of multi-function device */ /* keep track of device state */ unsigned int is_added:1; + unsigned int is_removed:1; /* pci_destroy_dev is called */ unsigned int is_busmaster:1; /* device is busmaster */ unsigned int no_msi:1; /* device may not use msi */ unsigned int block_cfg_access:1; /* config space access is blocked */ -- 1.8.1.4