Re: [PATCH v6 1/2] PCI: endpoint: pci-epf-vntb: Serialize virtual PCI bus scan

[Frank Li]

On Tue, Sep 01, 2026 at 03:32:37PM +0900, Koichiro Den wrote:
> The virtual PCI bus is scanned without holding the PCI rescan/remove
> lock. This can race with other PCI topology changes.
>
> Hold the lock across the bus scan and device addition.
>
> Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
> Suggested-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> Link: https://lore.kernel.org/r/3tgrcel5fl55ulf3zjya4fkz4t2ms7iwwjif5rnzn2rafsydd6@i4e5etm7uqvz/
> Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
> ---

It is okay for now, I suggest define cleanup by use guard() in future.

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

> Changes in v6:
>   - New patch based on Mani's review of v5 patch 4.
>
>  drivers/pci/endpoint/functions/pci-epf-vntb.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index c3caec927d74..412e8cc6fb1d 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -1332,14 +1332,19 @@ static int vpci_scan_bus(void *sysdata)
>  	struct pci_bus *vpci_bus;
>  	struct epf_ntb *ndev = sysdata;
>
> +	pci_lock_rescan_remove();
> +
>  	vpci_bus = pci_scan_bus(ndev->vbus_number, &vpci_ops, sysdata);
>  	if (!vpci_bus) {
>  		pr_err("create pci bus failed\n");
> +		pci_unlock_rescan_remove();
>  		return -EINVAL;
>  	}
>
>  	pci_bus_add_devices(vpci_bus);
>
> +	pci_unlock_rescan_remove();
> +
>  	return 0;
>  }
>
> --
> 2.51.0
>