Re: removable media revalidation - udev vs. devfs or static /dev

Martin J. Bligh
2004-01-08T01:07:37Z

--Greg KH <greg@kroah.com> wrote (on Wednesday, January 07, 2004 16:41:24 -0800):

> On Wed, Jan 07, 2004 at 04:32:26PM -0800, Martin J. Bligh wrote:
>> >> NOTE! We do have an alternative: if we were to just make block device
>> >> nodes support "readdir" and "lookup", you could just do
>> >>
>> >> open("/dev/sda/1" ...)
>> >>
>> >> and it magically works right. I've wanted to do this for a long time, but
>> >> every time I suggest allowing it, people scream.
>> >
>> > Hm, that would be nice. I don't remember seeing it being proposed
>> > before, what are the main complaints people have with this?
>>
>> Couldn't the partitions go under "/dev/sdaX/{1,2,3}" and solve the same
>> problem without doing magic on the devices?
>
> No, that's not the point. As discussed on irc, I think you now
> understand the issue (partitions not being present, media changed
> without kernel knowing about it, etc.)

I think it is the point ... you don't need to scan the device until
someone does "readdir" / "lookup" as Linus says above. Just this way
there's no duplexing of the block devices, just a magic directory node
(which might avoid the screams Linus mentions).
And it gets rid of the polling crap.

M.