Re: [PATCH] virtio-blk: emit udev event when device is resized

On Feb 25, 2013, at 5:39 PM, Kay Sievers <[email protected]> wrote:

> On Mon, Feb 25, 2013 at 11:12 PM, Greg KH <[email protected]> wrote:
> 
>> Hm, I thought we were frowning apon running binaries from udev rules
>> these days, especially ones that might have big consequences (like
>> resizing a disk image) like this.
>> 
>> Kay, am I right?
> 
> We removed most of them from the default setups, yes. But there is
> nothing wrong if people want to ship that in some package or as custom
> rules.
> 
> It looks fine to me, we would just not add such things to the default
> set of of rules these days.

That was not my intention. I just wanted to demonstrate that event like this
could be useful in cases like filesystem resize. We have a need for automatic
resize by our customers so we will ship our custom udev rules. It's perfectly
understandable that default udev rules will not have this.

Milos

> 
>> We already emit KOBJECT_CHANGE events when block devices change, from
>> within the block core code.  Why is the patch below needed instead of
>> using these events that are already generated?  How are virtio block
>> devices special?
> 
> I think we only do that for dm and md and a couple of special cases
> like loop and read-only settings.
> 
> Kay