lkml.org 
[lkml]   [2021]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [Patch v2 1/2] PCI: hv: Fix a race condition when removing the device
Date
> From: longli@linuxonhyperv.com <longli@linuxonhyperv.com>
> Sent: Wednesday, April 21, 2021 10:46 PM
> ...
> diff --git a/drivers/pci/controller/pci-hyperv.c
> b/drivers/pci/controller/pci-hyperv.c
> index 27a17a1e4a7c..fc948a2ed703 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -444,7 +444,6 @@ enum hv_pcibus_state {
> hv_pcibus_probed,
> hv_pcibus_installed,
> hv_pcibus_removing,
> - hv_pcibus_removed,
> hv_pcibus_maximum
> };
>
> @@ -3305,13 +3304,22 @@ static int hv_pci_remove(struct hv_device *hdev)
>
> hbus = hv_get_drvdata(hdev);
> if (hbus->state == hv_pcibus_installed) {
> + tasklet_disable(&hdev->channel->callback_event);
> + hbus->state = hv_pcibus_removing;
> + tasklet_enable(&hdev->channel->callback_event);
> + destroy_workqueue(hbus->wq);

If we test "rmmod pci-hyperv", I suspect the warning will be printed:
hv_pci_remove() -> hv_pci_bus_exit() -> hv_pci_start_relations_work():

if (hbus->state == hv_pcibus_removing) {
dev_info(&hbus->hdev->device,
"PCI VMBus BUS_RELATIONS: ignored\n");
return -ENOENT;
}

Ideally we'd like to avoid the warning in the driver unloading case.

BTW, can you please add "hbus->wq = NULL;" after the line
"destroy_workqueue(hbus->wq);"? In case some other function could
still try to use hbus->wq by accident in the future, the error would be
easier to be understood.

\
 
 \ /
  Last update: 2021-04-23 09:10    [W:0.069 / U:0.512 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site