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From:   Paulo Alcantara <pc@cjr.nz>
To:     Enzo Matsumiya <ematsumiya@suse.de>, linux-cifs@vger.kernel.org
Cc:     smfrench@gmail.com, ronniesahlberg@gmail.com,
        nspmangalore@gmail.com, Enzo Matsumiya <ematsumiya@suse.de>
Subject: Re: [PATCH 0/2] Introduce dns_interval procfs setting
In-Reply-To: <20220608215444.1216-1-ematsumiya@suse.de>
References: <20220608215444.1216-1-ematsumiya@suse.de>
Date:   Thu, 09 Jun 2022 11:53:13 -0300
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Hi Enzo,

Enzo Matsumiya <ematsumiya@suse.de> writes:

> These 2 patches are a simple way to fix the DNS issue that
> currently exists in cifs, where the upcall to key.dns_resolver will
> always return 0 for the record TTL, hence, making the resolve worker
> always use the default value SMB_DNS_RESOLVE_INTERVAL_DEFAULT
> (currently 600 seconds).
>
> This also makes the new setting `dns_interval' user-configurable via
> procfs (/proc/fs/cifs/dns_interval).

How is the user supposed to know which TTL value will be used?  If the
expire time is set by either key.dns_resolver or any other program used
for dns_resolver key, the above setting would no longer work and users
might get confused.