[PATCH v3 1/2] virt: vbox: convert to use dev_groups

[PATCH v3 1/2] virt: vbox: convert to use dev_groups

[Jiasheng Jiang]

The driver core supports the ability to handle the creation and removal
of device-specific sysfs files in a race-free manner. Moreover, it can
guarantee the success of creation. Therefore, it should be better to
convert to use dev_groups.

Fixes: 0ba002bc4393 ("virt: Add vboxguest driver for Virtual Box Guest integration")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
Change log:

v2-> v3:

1. Switch to use an attribute group.

v1 -> v2:

1. Use gdev->dev instead of dev.
2. Remove file when creation failed.
---
 drivers/virt/vboxguest/vboxguest_linux.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/virt/vboxguest/vboxguest_linux.c b/drivers/virt/vboxguest/vboxguest_linux.c
index 4ccfd30c2a30..6fc81347ae72 100644
--- a/drivers/virt/vboxguest/vboxguest_linux.c
+++ b/drivers/virt/vboxguest/vboxguest_linux.c
@@ -270,6 +270,13 @@ static ssize_t host_features_show(struct device *dev,
 static DEVICE_ATTR_RO(host_version);
 static DEVICE_ATTR_RO(host_features);
 
+static struct attribute *vbg_pci_attrs[] = {
+	&dev_attr_host_version.attr,
+	&dev_attr_host_features.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(vbg_pci);
+
 /**
  * Does the PCI detection and init of the device.
  *
@@ -390,8 +397,6 @@ static int vbg_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
 	}
 
 	pci_set_drvdata(pci, gdev);
-	device_create_file(dev, &dev_attr_host_version);
-	device_create_file(dev, &dev_attr_host_features);
 
 	vbg_info("vboxguest: misc device minor %d, IRQ %d, I/O port %x, MMIO at %pap (size %pap)\n",
 		 gdev->misc_device.minor, pci->irq, gdev->io_port,
@@ -422,8 +427,6 @@ static void vbg_pci_remove(struct pci_dev *pci)
 	mutex_unlock(&vbg_gdev_mutex);
 
 	free_irq(pci->irq, gdev);
-	device_remove_file(gdev->dev, &dev_attr_host_features);
-	device_remove_file(gdev->dev, &dev_attr_host_version);
 	misc_deregister(&gdev->misc_device_user);
 	misc_deregister(&gdev->misc_device);
 	vbg_core_exit(gdev);
@@ -488,6 +491,7 @@ MODULE_DEVICE_TABLE(pci,  vbg_pci_ids);
 
 static struct pci_driver vbg_pci_driver = {
 	.name		= DEVICE_NAME,
+	.dev_groups	= vbg_pci_groups,
 	.id_table	= vbg_pci_ids,
 	.probe		= vbg_pci_probe,
 	.remove		= vbg_pci_remove,
-- 
2.25.1

Re: [PATCH v3 1/2] virt: vbox: convert to use dev_groups

[Hans de Goede]

Hi,

On 9/1/22 16:46, Jiasheng Jiang wrote:
> The driver core supports the ability to handle the creation and removal
> of device-specific sysfs files in a race-free manner. Moreover, it can
> guarantee the success of creation. Therefore, it should be better to
> convert to use dev_groups.
> 
> Fixes: 0ba002bc4393 ("virt: Add vboxguest driver for Virtual Box Guest integration")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> ---
> Change log:
> 
> v2-> v3:
> 
> 1. Switch to use an attribute group.
> 
> v1 -> v2:
> 
> 1. Use gdev->dev instead of dev.
> 2. Remove file when creation failed.
> ---
>  drivers/virt/vboxguest/vboxguest_linux.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/virt/vboxguest/vboxguest_linux.c b/drivers/virt/vboxguest/vboxguest_linux.c
> index 4ccfd30c2a30..6fc81347ae72 100644
> --- a/drivers/virt/vboxguest/vboxguest_linux.c
> +++ b/drivers/virt/vboxguest/vboxguest_linux.c
> @@ -270,6 +270,13 @@ static ssize_t host_features_show(struct device *dev,
>  static DEVICE_ATTR_RO(host_version);
>  static DEVICE_ATTR_RO(host_features);
>  
> +static struct attribute *vbg_pci_attrs[] = {
> +	&dev_attr_host_version.attr,
> +	&dev_attr_host_features.attr,
> +	NULL,
> +};
> +ATTRIBUTE_GROUPS(vbg_pci);
> +
>  /**
>   * Does the PCI detection and init of the device.
>   *
> @@ -390,8 +397,6 @@ static int vbg_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
>  	}
>  
>  	pci_set_drvdata(pci, gdev);
> -	device_create_file(dev, &dev_attr_host_version);
> -	device_create_file(dev, &dev_attr_host_features);
>  
>  	vbg_info("vboxguest: misc device minor %d, IRQ %d, I/O port %x, MMIO at %pap (size %pap)\n",
>  		 gdev->misc_device.minor, pci->irq, gdev->io_port,
> @@ -422,8 +427,6 @@ static void vbg_pci_remove(struct pci_dev *pci)
>  	mutex_unlock(&vbg_gdev_mutex);
>  
>  	free_irq(pci->irq, gdev);
> -	device_remove_file(gdev->dev, &dev_attr_host_features);
> -	device_remove_file(gdev->dev, &dev_attr_host_version);
>  	misc_deregister(&gdev->misc_device_user);
>  	misc_deregister(&gdev->misc_device);
>  	vbg_core_exit(gdev);
> @@ -488,6 +491,7 @@ MODULE_DEVICE_TABLE(pci,  vbg_pci_ids);
>  
>  static struct pci_driver vbg_pci_driver = {
>  	.name		= DEVICE_NAME,
> +	.dev_groups	= vbg_pci_groups,
>  	.id_table	= vbg_pci_ids,
>  	.probe		= vbg_pci_probe,
>  	.remove		= vbg_pci_remove,