RE: [PATCH v2] hyperv: Make remove callback of hyperv driver void returned

From: Michael Kelley (LINUX)
Date: Wed Jan 04 2023 - 22:27:15 EST


From: Dawei Li <set_pte_at@xxxxxxxxxxx> Sent: Sunday, January 1, 2023 9:04 PM
>

Historically, patches for the VMBus drivers in the drivers/hv directory
have a subject prefix of "Drivers: hv:", not "hyperv". These changes touch
VMBus drivers that are scattered in other source tree directories as well,
but let's still use the "Drivers: hv:" prefix as the best historical precedent.

> Since commit fc7a6209d571 ("bus: Make remove callback return void") forces
> bus_type::remove be void-returned, it doesn't make much sense for any bus
> based driver implementing remove callbalk to return non-void to its caller.
>
> This change is for hyperv bus based drivers.

VMBus is the name of the bus, so let's reference that instead of just
Hyper-V. Note the spelling and capitalization of "Hyper-V" and "VMBus".
We're trying to be more consistent going forward. :-) And following
documented guidance to avoid language like "this patch" or "this
change" in a commit message, I'd suggest this wording:

As such, change the remove function for Hyper-V VMBus based drivers to
return void.

>
> Signed-off-by: Dawei Li <set_pte_at@xxxxxxxxxxx>
> ---
> v1 -> v2
> - Fixed null dereference issue and deprecated comments, based on comments
> by Liu Wei.
> - Fixed building issue.
> - Rebased on latest hyperv-next.
>
> v1
> - https://lore.kernel.org/all/TYCP286MB232373567792ED1AC5E0849FCA189@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
> ---
> drivers/gpu/drm/hyperv/hyperv_drm_drv.c | 4 +---
> drivers/hid/hid-hyperv.c | 4 +---
> drivers/hv/hv_balloon.c | 5 +----
> drivers/hv/hv_util.c | 4 +---
> drivers/input/serio/hyperv-keyboard.c | 4 +---
> drivers/net/hyperv/netvsc_drv.c | 5 ++---
> drivers/pci/controller/pci-hyperv.c | 8 ++------
> drivers/scsi/storvsc_drv.c | 4 +---
> drivers/uio/uio_hv_generic.c | 5 ++---
> drivers/video/fbdev/hyperv_fb.c | 5 +----
> include/linux/hyperv.h | 2 +-
> net/vmw_vsock/hyperv_transport.c | 4 +---
> 12 files changed, 15 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> index ca127ff797f7..d117fff26d99 100644
> --- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> +++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> @@ -165,7 +165,7 @@ static int hyperv_vmbus_probe(struct hv_device *hdev,
> return ret;
> }
>
> -static int hyperv_vmbus_remove(struct hv_device *hdev)
> +static void hyperv_vmbus_remove(struct hv_device *hdev)
> {
> struct drm_device *dev = hv_get_drvdata(hdev);
> struct hyperv_drm_device *hv = to_hv(dev);
> @@ -176,8 +176,6 @@ static int hyperv_vmbus_remove(struct hv_device *hdev)
> hv_set_drvdata(hdev, NULL);
>
> vmbus_free_mmio(hv->mem->start, hv->fb_size);
> -
> - return 0;
> }
>
> static int hyperv_vmbus_suspend(struct hv_device *hdev)
> diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c
> index ab57b49a44ed..ef16c2a54362 100644
> --- a/drivers/hid/hid-hyperv.c
> +++ b/drivers/hid/hid-hyperv.c
> @@ -535,7 +535,7 @@ static int mousevsc_probe(struct hv_device *device,
> }
>
>
> -static int mousevsc_remove(struct hv_device *dev)
> +static void mousevsc_remove(struct hv_device *dev)
> {
> struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
>
> @@ -544,8 +544,6 @@ static int mousevsc_remove(struct hv_device *dev)
> hid_hw_stop(input_dev->hid_device);
> hid_destroy_device(input_dev->hid_device);
> mousevsc_free_device(input_dev);
> -
> - return 0;
> }
>
> static int mousevsc_suspend(struct hv_device *dev)
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index cbe43e2567a7..3eece5e5b0a1 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -2042,7 +2042,7 @@ static int balloon_probe(struct hv_device *dev,
> return ret;
> }
>
> -static int balloon_remove(struct hv_device *dev)
> +static void balloon_remove(struct hv_device *dev)
> {
> struct hv_dynmem_device *dm = hv_get_drvdata(dev);
> struct hv_hotadd_state *has, *tmp;
> @@ -2083,8 +2083,6 @@ static int balloon_remove(struct hv_device *dev)
> kfree(has);
> }
> spin_unlock_irqrestore(&dm_device.ha_lock, flags);
> -
> - return 0;
> }
>
> static int balloon_suspend(struct hv_device *hv_dev)
> @@ -2164,7 +2162,6 @@ static struct hv_driver balloon_drv = {
>
> static int __init init_balloon_drv(void)
> {
> -

Nit: This is a gratuitous whitespace change. By itself it doesn't
warrant re-spinning the patch, but if you respin to update the
Subject and commit message, it would be good to remove
this as well.

> return vmbus_driver_register(&balloon_drv);
> }
>
> diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
> index 835e6039c186..24995ac41c86 100644
> --- a/drivers/hv/hv_util.c
> +++ b/drivers/hv/hv_util.c
> @@ -602,7 +602,7 @@ static int util_probe(struct hv_device *dev,
> return ret;
> }
>
> -static int util_remove(struct hv_device *dev)
> +static void util_remove(struct hv_device *dev)
> {
> struct hv_util_service *srv = hv_get_drvdata(dev);
>
> @@ -610,8 +610,6 @@ static int util_remove(struct hv_device *dev)
> srv->util_deinit();
> vmbus_close(dev->channel);
> kfree(srv->recv_buffer);
> -
> - return 0;
> }
>
> /*
> diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-
> keyboard.c
> index d62aefb2e245..31def6ce5157 100644
> --- a/drivers/input/serio/hyperv-keyboard.c
> +++ b/drivers/input/serio/hyperv-keyboard.c
> @@ -369,7 +369,7 @@ static int hv_kbd_probe(struct hv_device *hv_dev,
> return error;
> }
>
> -static int hv_kbd_remove(struct hv_device *hv_dev)
> +static void hv_kbd_remove(struct hv_device *hv_dev)
> {
> struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
>
> @@ -378,8 +378,6 @@ static int hv_kbd_remove(struct hv_device *hv_dev)
> kfree(kbd_dev);
>
> hv_set_drvdata(hv_dev, NULL);
> -
> - return 0;
> }
>
> static int hv_kbd_suspend(struct hv_device *hv_dev)
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index 89eb4f179a3c..025f805e1ed9 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -2594,7 +2594,7 @@ static int netvsc_probe(struct hv_device *dev,
> return ret;
> }
>
> -static int netvsc_remove(struct hv_device *dev)
> +static void netvsc_remove(struct hv_device *dev)
> {
> struct net_device_context *ndev_ctx;
> struct net_device *vf_netdev, *net;
> @@ -2603,7 +2603,7 @@ static int netvsc_remove(struct hv_device *dev)
> net = hv_get_drvdata(dev);
> if (net == NULL) {
> dev_err(&dev->device, "No net device to remove\n");
> - return 0;
> + return;
> }
>
> ndev_ctx = netdev_priv(net);
> @@ -2637,7 +2637,6 @@ static int netvsc_remove(struct hv_device *dev)
>
> free_percpu(ndev_ctx->vf_stats);
> free_netdev(net);
> - return 0;
> }
>
> static int netvsc_suspend(struct hv_device *dev)
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 583d3aad6908..e46d9a14053f 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -3813,13 +3813,10 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool
> keep_devs)
> /**
> * hv_pci_remove() - Remove routine for this VMBus channel
> * @hdev: VMBus's tracking struct for this root PCI bus
> - *
> - * Return: 0 on success, -errno on failure
> */
> -static int hv_pci_remove(struct hv_device *hdev)
> +static void hv_pci_remove(struct hv_device *hdev)
> {
> struct hv_pcibus_device *hbus;
> - int ret;
>
> hbus = hv_get_drvdata(hdev);
> if (hbus->state == hv_pcibus_installed) {
> @@ -3842,7 +3839,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> pci_unlock_rescan_remove();
> }
>
> - ret = hv_pci_bus_exit(hdev, false);
> + hv_pci_bus_exit(hdev, false);
>
> vmbus_close(hdev->channel);
>
> @@ -3855,7 +3852,6 @@ static int hv_pci_remove(struct hv_device *hdev)
> hv_put_dom_num(hbus->bridge->domain_nr);
>
> kfree(hbus);
> - return ret;
> }
>
> static int hv_pci_suspend(struct hv_device *hdev)
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> index 3c5b7e4227b2..02f9d1a6f4ac 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -2092,7 +2092,7 @@ static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
> return scsi_change_queue_depth(sdev, queue_depth);
> }
>
> -static int storvsc_remove(struct hv_device *dev)
> +static void storvsc_remove(struct hv_device *dev)
> {
> struct storvsc_device *stor_device = hv_get_drvdata(dev);
> struct Scsi_Host *host = stor_device->host;
> @@ -2108,8 +2108,6 @@ static int storvsc_remove(struct hv_device *dev)
> scsi_remove_host(host);
> storvsc_dev_remove(dev);
> scsi_host_put(host);
> -
> - return 0;
> }
>
> static int storvsc_suspend(struct hv_device *hv_dev)
> diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
> index c08a6cfd119f..20d9762331bd 100644
> --- a/drivers/uio/uio_hv_generic.c
> +++ b/drivers/uio/uio_hv_generic.c
> @@ -355,20 +355,19 @@ hv_uio_probe(struct hv_device *dev,
> return ret;
> }
>
> -static int
> +static void
> hv_uio_remove(struct hv_device *dev)
> {
> struct hv_uio_private_data *pdata = hv_get_drvdata(dev);
>
> if (!pdata)
> - return 0;
> + return;
>
> sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr);
> uio_unregister_device(&pdata->info);
> hv_uio_cleanup(dev, pdata);
>
> vmbus_free_ring(dev->channel);
> - return 0;
> }
>
> static struct hv_driver hv_uio_drv = {
> diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
> index 3ce746a46179..cfa6a7c1eeb3 100644
> --- a/drivers/video/fbdev/hyperv_fb.c
> +++ b/drivers/video/fbdev/hyperv_fb.c
> @@ -1240,8 +1240,7 @@ static int hvfb_probe(struct hv_device *hdev,
> return ret;
> }
>
> -
> -static int hvfb_remove(struct hv_device *hdev)
> +static void hvfb_remove(struct hv_device *hdev)
> {
> struct fb_info *info = hv_get_drvdata(hdev);
> struct hvfb_par *par = info->par;
> @@ -1262,8 +1261,6 @@ static int hvfb_remove(struct hv_device *hdev)
>
> hvfb_putmem(hdev, info);
> framebuffer_release(info);
> -
> - return 0;
> }
>
> static int hvfb_suspend(struct hv_device *hdev)
> diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
> index 85f7c5a63aa6..cd5cb9f6fae0 100644
> --- a/include/linux/hyperv.h
> +++ b/include/linux/hyperv.h
> @@ -1273,7 +1273,7 @@ struct hv_driver {
> } dynids;
>
> int (*probe)(struct hv_device *, const struct hv_vmbus_device_id *);
> - int (*remove)(struct hv_device *);
> + void (*remove)(struct hv_device *dev);
> void (*shutdown)(struct hv_device *);
>
> int (*suspend)(struct hv_device *);
> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> index 59c3e2697069..7cb1a9d2cdb4 100644
> --- a/net/vmw_vsock/hyperv_transport.c
> +++ b/net/vmw_vsock/hyperv_transport.c
> @@ -879,13 +879,11 @@ static int hvs_probe(struct hv_device *hdev,
> return 0;
> }
>
> -static int hvs_remove(struct hv_device *hdev)
> +static void hvs_remove(struct hv_device *hdev)
> {
> struct vmbus_channel *chan = hdev->channel;
>
> vmbus_close(chan);
> -
> - return 0;
> }
>
> /* hv_sock connections can not persist across hibernation, and all the hv_sock
> --
> 2.25.1