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From: Shyam Prasad N <nspmangalore@gmail.com>
To: "Steve French" <smfrench@gmail.com>,
	"Paulo Alcantara" <pc@cjr.nz>, "Aurélien Aptel" <aaptel@suse.com>,
	CIFS <linux-cifs@vger.kernel.org>
Subject: [PATCH] cifs: use the expiry output of dns_query to schedule next resolution
Date: Thu, 20 May 2021 23:30:42 +0530	[thread overview]
Message-ID: <CANT5p=qzxhOjAY_s9NMsiS5F4FtsNJXytHbihF+esv+n4ytDvw@mail.gmail.com> (raw)

Hi,

We recently fixed DNS resolution of the server hostname during reconnect.
However, server IP address may change, even when the old one continues
to server (although sub-optimally).

We should schedule the next DNS resolution based on the TTL of
the DNS record used for the last resolution. This way, we resolve the
server hostname again when a DNS record expires.

Please review the changes.

@Paulo Alcantara I know this can create merge conflicts when your
patch gets merged.
I can rebase my changes on top of yours when it gets merged.

@David Howells
Something worth noting here is that the keyutils key.dns_resolver
upcall resolves the hostname, but does not return the expiry time. I'm
falling back to a default value of 600s for now.

I assumed that this commit of yours was a workaround to this exact
problem in getaddrinfo().
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/commit/?id=75e7568dc516db698093b33ea273e1b4a30b70be
Have you since been able derive the TTL field from the DNS records?

https://github.com/sprasad-microsoft/smb-kernel-client/pull/1

-- 
Regards,
Shyam

             reply	other threads:[~2021-05-20 18:00 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-20 18:00 Shyam Prasad N [this message]
2021-05-20 18:09 ` [PATCH] cifs: use the expiry output of dns_query to schedule next resolution Paulo Alcantara

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