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

Mika Penttilä
2004-01-07T19:29:14Z

Greg KH wrote:

>On Wed, Jan 07, 2004 at 09:23:39PM +0200, Mika Penttilä wrote:
>
>
>>Greg KH wrote:
>>
>>
>>>On Wed, Jan 07, 2004 at 10:38:31AM -0800, Linus Torvalds wrote:
>>>
>>>
>>>>And it really has to create _all_ of them, exactly because there's no way
>>>>to know ahead-of-time which of them will be available.
>>>>
>>>>Then, user space can just access "/dev/sda1" or whatever, and the act of
>>>>accessing it will force the re-scan.
>>>>
>>>>
>>>>
>>>>
>>>Hm, that would work, but what about a user program that just polls on
>>>the device, as the rest of this thread discusses? As removable devices
>>>are not the "norm" it would seem a bit of overkill to create 16
>>>partitions for every block device, if they need them or not.
>>>
>>>
>>>
>>Accessing the partition would not cause the rescan (accessing the whole
>>disk causes.) I think devfs does/did this rescan on access.
>>
>>
>
>It would rescan on access of a partition or the main block device?
>
>If accessing the partition doesn't work, than having udev create all
>partitions wouldn't help anything :(
>
>thanks,
>
>greg k-h
>
>

Right, rescan on access of main block device works, partition not, afaics.

--Mika