Re: [PATCH 0/2] make automatic device_id generation possible

Karel Zak
2015-03-05T12:03:12Z

On Thu, Mar 05, 2015 at 09:58:29AM +0900, Sergey Senozhatsky wrote:
> Hello,
>
> On (03/05/15 09:20), Minchan Kim wrote:
> > I'm not against but I want to know why we should support
> > user-defined device id. What usecase do you have in mind?
> >
>
> hm, you never know what people can come up with. that's probably the
> strongest support argument I can provide. I wish there was something
> like - my friend Mike has a "device /dev/zram1 is always swap device,
> device /dev/zram$(id -u) is a per-user zram device (he finds it useful,

I have doubts that promise stable device names is good idea. The usual
way is to care about FS/SWAP identifiers (LABEL=, or UUID=), and for
example udevd should be able to create a stable /dev/disk/by-*
symlinks.

So for your friend Mike is better to have UUID= in /etc/fstab and
force mkswap or mkfs to use still the same UUID.

> user defined id support comes at a price of ~10 lines of code, or even
> less. we waste much more code to show ->stats, and not all of them are

I think it's not about number of code lines, it's kernel, you have to
support it forever, etc. It's easy to add a new feature, but you don't
have to do it right now :)

Karel

--
Karel Zak <kzak@redhat.com>