Re: [PATCH 2/6] Adjust watch_queue documentation to mention mount and superblock watches. [ver #5]

Randy Dunlap
2019-07-01T14:52:06Z

On 7/1/19 1:52 AM, David Howells wrote:
> Randy Dunlap <rdunlap@infradead.org> wrote:
>
>> I'm having a little trouble parsing that sentence.
>> Could you clarify it or maybe rewrite/modify it?
>> Thanks.
>
> How about:
>
> * ``info_filter`` and ``info_mask`` act as a filter on the info field of the
> notification record. The notification is only written into the buffer if::
>
> (watch.info & info_mask) == info_filter
>
> This could be used, for example, to ignore events that are not exactly on
> the watched point in a mount tree by specifying NOTIFY_MOUNT_IN_SUBTREE
> must not be set, e.g.::
>
> {
> .type = WATCH_TYPE_MOUNT_NOTIFY,
> .info_filter = 0,
> .info_mask = NOTIFY_MOUNT_IN_SUBTREE,
> .subtype_filter = ...,
> }
>
> as an event would be only permissible with this filter if::
>
> (watch.info & NOTIFY_MOUNT_IN_SUBTREE) == 0
>
> David
>

Yes, better. Thanks.

--
~Randy