Kevin P. Fleming writes:
> (I'm resending this due to lack of any response on the first
> attempt... and since I didn't see this patch appear in
> 2.4.8-pre(2/3))
Sorry, I haven't had time to respond until now. I'm afraid I don't
like this patch. Parts should be unnecessary, and it introduces a
race.
> The attached patch (which touches nearly every block device driver that
> supports partitioned media) fixes a couple of problems when devfs is in use:
>
> - when a block device's media is "revalidated", the partition table
> is re-read and /dev nodes are created for those partitions, but the
> previously existing entries are not removed first. this can easily
> lead to "left over" entries when the partition table is changed
> (either by partition table editing or replacement of removable
> media)
This should be done already. devfs_register_partitions() has the
following code:
if ( unregister || (dev->part[part + minor].nr_sects < 1) ) {
devfs_unregister (dev->part[part + minor].de);
dev->part[part + minor].de = NULL;
continue;
}
That should unregister "empty" partitions. Before emplying a
sledgehammer approach of killing everything, let's try to figure out
why the above code isn't dong what I intended. When I first put that
code in, I tested that revalidating the partition table worked OK. It
did.
> - if media is ejected from a removable media device (normally done
> using an ioctl), the /dev entries for that media do not get removed
Again, they should. And reports I got back originally said it was
working OK.
Furthermore, your patch introduces a race: by unregistering
everything, the unique number (for /dev/discs/disc%d) is freed, and
then later allocated. Hopefully for the same device. But maybe not:
another driver could be loaded and grab the number. And that is
definately wrong.
> - if a block device driver has sub-drivers (specifically the IDE
> layer) loaded as modules, and one of those sub-drivers is unloaded,
> the /dev nodes it was responsible for do not get removed. this
> problem will not occur if the main block driver (at the major number
> level) is unloaded, only for sub-drivers
Specifically which entries do not get removed (and you think should
be)?
Regards,
Richard....
Permanent: rgooch@atnf.csiro.au
Current: rgooch@ras.ucalgary.ca
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This archive was generated by hypermail 2b29 : Tue Aug 07 2001 - 21:00:28 EST