From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A76BC3815B for ; Mon, 20 Apr 2020 13:13:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BED8206DD for ; Mon, 20 Apr 2020 13:13:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="f/2co/SU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726840AbgDTNNw (ORCPT ); Mon, 20 Apr 2020 09:13:52 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:23238 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726050AbgDTNNs (ORCPT ); Mon, 20 Apr 2020 09:13:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587388427; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IYew2ybNbEYlxnWhOLAX8rprgalSjY8htLDKj7llLh0=; b=f/2co/SUzVgqO+vx5jBvEWWT0ZbE7IJgrb7wpxxCkS6cnhDWFHcocKa5iYw8v6fhe1Bf0j WXtK1UTtA1fjvHYzfNiQv7Y2+yWzFVI0hGDs6w1QLZXmeErm0ZXcx1hsJYmNDitVS35fxK RBr57UUVzEb+ct7eka7VJO0DKky4A7E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-109-8q1U0xdCNU2fff9u2tmIGQ-1; Mon, 20 Apr 2020 09:13:45 -0400 X-MC-Unique: 8q1U0xdCNU2fff9u2tmIGQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 80352149C1; Mon, 20 Apr 2020 13:13:43 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-113-129.rdu2.redhat.com [10.10.113.129]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0BDD510013A1; Mon, 20 Apr 2020 13:13:40 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <87imhvj7m6.fsf@cjr.nz> References: <87imhvj7m6.fsf@cjr.nz> <3865908.1586874010@warthog.procyon.org.uk> <927453.1587285472@warthog.procyon.org.uk> To: Paulo Alcantara Cc: dhowells@redhat.com, Steve French , linux-nfs , CIFS , linux-afs@lists.infradead.org, ceph-devel@vger.kernel.org, keyrings@vger.kernel.org, Network Development , LKML , fweimer@redhat.com Subject: Re: What's a good default TTL for DNS keys in the kernel MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <1136023.1587388420.1@warthog.procyon.org.uk> Content-Transfer-Encoding: quoted-printable Date: Mon, 20 Apr 2020 14:13:40 +0100 Message-ID: <1136024.1587388420@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Paulo Alcantara wrote: > >> For SMB3/CIFS mounts, Paulo added support last year for automatic > >> reconnect if the IP address of the server changes. It also is helpfu= l > >> when DFS (global name space) addresses change. > > > > What happens if the IP address the superblock is going to changes, the= n > > another mount is made back to the original IP address? Does the secon= d mount > > just pick the original superblock? > = > It is going to transparently reconnect to the new ip address, SMB share, > and cifs superblock is kept unchanged. We, however, update internal > TCP_Server_Info structure to reflect new destination ip address. > = > For the second mount, since the hostname (extracted out of the UNC path > at mount time) resolves to a new ip address and that address was saved e= arlier > in TCP_Server_Info structure during reconnect, we will end up > reusing same cifs superblock as per fs/cifs/connect.c:cifs_match_super()= . Would that be a bug? David