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

On Thu, Jul 23, 2020 at 12:48 PM David Howells [off-list ref] wrote:

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                __u32   topology_changes;
                __u32   attr_changes;
                __u32   aux_topology_changes;

Being 32bit this introduces wraparound effects.  Is that really worth it?

You'd have to make 2 billion changes without whoever's monitoring getting a
chance to update their counters.  But maybe it's not worth it putting them
here.  If you'd prefer, I can make the counters all 64-bit and just retrieve
them with fsinfo().

Yes, I think that would be preferable.

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        n->watch.info & NOTIFY_MOUNT_IS_RECURSIVE if true indicates that
        the notifcation was generated by an event (eg. SETATTR) that was
        applied recursively.  The notification is only generated for the
        object that initially triggered it.

Unused in this patchset.  Please don't add things to the API which are not
used.

Christian Brauner has patches for mount_setattr() that will need to use this.

Fine, then that patch can add the flag.

Thanks,
Miklos