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

On Wed, Aug 5, 2020 at 3:54 AM Ian Kent [off-list ref] wrote:

quoted

quoted

It's way more useful to have these in the notification than
obtainable
via fsinfo() IMHO.

What is it useful for?

Only to verify that you have seen all the notifications.

If you have to grab that info with a separate call then the count
isn't necessarily consistent because other notifications can occur
while you grab it.

No, no no.   The watch queue will signal an overflow, without any
additional overhead for the normal case.  If you think of this as a
protocol stack, then the overflow detection happens on the transport
layer, instead of the application layer.  The application layer is
responsible for restoring state in case of a transport layer error,
but detection of that error is not the responsibility of the
application layer.


Thanks,
Miklos