Re: [PATCH] blkfront: add uevent for size change

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Apr 11, 2017 at 12:24:09PM -0700, Marc Olson wrote:
> When a blkfront device is resized from dom0, emit a KOBJ_CHANGE uevent to
> notify the guest about the change. This allows for custom udev rules, such
> as automatically resizing a filesystem, when an event occurs.

Looks pretty reasonable.

Could you confirm what the udevadm --monitor --kernel --udev emits when this happens?

Thanks!

> 
> Signed-off-by: Marc Olson <marcolso@amazon.com>
> ---
>  drivers/block/xen-blkfront.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index 2fee2ee..66abf9c 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -1996,6 +1996,7 @@ static void blkfront_connect(struct blkfront_info *info)
>  	unsigned long sector_size;
>  	unsigned int physical_sector_size;
>  	unsigned int binfo;
> +	char *envp[] = { "RESIZE=1", NULL };
>  	int err;
>  
>  	switch (info->connected) {
> @@ -2012,6 +2013,8 @@ static void blkfront_connect(struct blkfront_info *info)
>  		       sectors);
>  		set_capacity(info->gd, sectors);
>  		revalidate_disk(info->gd);
> +		kobject_uevent_env(&disk_to_dev(info->gd)->kobj,
> +				   KOBJ_CHANGE, envp);
>  
>  		return;
>  	case BLKIF_STATE_SUSPENDED:
> -- 
> 2.7.4
>