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authorDexuan Cui <decui@microsoft.com>2016-11-10 07:19:52 +0000
committerBjorn Helgaas <bhelgaas@google.com>2016-11-16 16:46:44 -0600
commite74d2ebdda33b3bdd1826b5b92e9aa45bdf92bb3 (patch)
tree77333536f5741d3117d404b403f3123d098d6b11 /drivers/pci/host/pci-hyperv.c
parent17978524a636d007e6b929304ae3eb5ea0371019 (diff)
PCI: hv: Delete the device earlier from hbus->children for hot-remove
After we send a PCI_EJECTION_COMPLETE message to the host, the host will immediately send us a PCI_BUS_RELATIONS message with relations->device_count == 0, so pci_devices_present_work(), running on another thread, can find the being-ejected device, mark the hpdev->reported_missing to true, and run list_move_tail()/list_del() for the device -- this races hv_eject_device_work() -> list_del(). Move the list_del() in hv_eject_device_work() to an earlier place, i.e., before we send PCI_EJECTION_COMPLETE, so later the pci_devices_present_work() can't see the device. Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jake Oshins <jakeo@microsoft.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com>
Diffstat (limited to 'drivers/pci/host/pci-hyperv.c')
-rw-r--r--drivers/pci/host/pci-hyperv.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index b1747469a32c..a63c3a4f6c7c 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1582,6 +1582,10 @@ static void hv_eject_device_work(struct work_struct *work)
pci_dev_put(pdev);
}
+ spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
+ list_del(&hpdev->list_entry);
+ spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
+
memset(&ctxt, 0, sizeof(ctxt));
ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
@@ -1590,10 +1594,6 @@ static void hv_eject_device_work(struct work_struct *work)
sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
VM_PKT_DATA_INBAND, 0);
- spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);
- list_del(&hpdev->list_entry);
- spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
-
put_pcichild(hpdev, hv_pcidev_ref_childlist);
put_pcichild(hpdev, hv_pcidev_ref_pnp);
put_hvpcibus(hpdev->hbus);