Re: [PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications [ver #5]

[Miklos Szeredi]

On Fri, Jul 24, 2020 at 1:36 PM David Howells <dhowells@xxxxxxxxxx> wrote:
>
> Ian Kent <raven@xxxxxxxxxx> wrote:
>
> > I was wondering about id re-use.
> >
> > Assuming that ids that are returned to the idr db are re-used
> > what would the chance that a recently used id would end up
> > being used?
> >
> > Would that chance increase as ids are consumed and freed over
> > time?
>
> I've added something to deal with that in the fsinfo branch.  I've given each
> mount object and superblock a supplementary 64-bit unique ID that's not likely
> to repeat before we're no longer around to have to worry about it.
>
> fsinfo() then allows you to retrieve them by path or by mount ID.

Shouldn't the notification interface provide the unique ID?

Thanks,
Miklos

>
> So, yes, mnt_id and s_dev are not unique and may be reused very quickly, but
> I'm also providing uniquifiers that you can check.
>
> David
>