On 9/5/2014 3:29 PM, Tejun Heo wrote:

Hello, Dmitry.

On Fri, Sep 05, 2014 at 11:10:03AM -0700, Dmitry Torokhov wrote:

quoted

I do not agree that it is actually user-visible change: generally speaking you
do not really know if device is there or not. They come and go. Like I said,
consider all permutations, with hot-pluggable buses, deferred probing, etc,

It is for storage devices which always have guaranteed synchronous
probing on module load and well-defined probing order.  Sure, modern
setups are a lot more dynamic but I'm quite certain that there are
setups in the wild which depend on storage driver loading being
synchronous.  We can't simply declare one day that such behavior is
broken and break, most likely, their boots.

we even depend on this in the mount-by-label cases

many setups assume that the internal storage prevails over the USB stick in the case of conflicts.
it's a security issue; you don't want the built in secure bootloader that has a kernel root argument
by label/uuid.
the security there tends to assume that built-in wins over USB