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=-6.0 required=3.0 tests=BAYES_00,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 98A86C48BCD for ; Wed, 9 Jun 2021 15:00:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 84ED36124C for ; Wed, 9 Jun 2021 15:00:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238241AbhFIPCV (ORCPT ); Wed, 9 Jun 2021 11:02:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:52607 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238378AbhFIPCV (ORCPT ); Wed, 9 Jun 2021 11:02:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623250826; 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=4+Zwf+/c3B/K41AfhzwQXACQelqrDHkoWlCWo2Ylgyo=; b=eWb6hnCwMdzfeDXpF6sO1olbaqCVFUTnZCTq7MIKiGHabbhYckjy1/YSYd8P7uwf76fSQY wT7T5ayJctxNmhJF1owNRtXWiEqqfu6XQOsLUF5viYhqiTQ6JzIbKwuDiyZL6dd3v0OM1u 5dm+U24UXJaASBjBAj7RgAbXtxIurN8= 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-269-eJ6lviPIMnWCxcg8T7Wt7Q-1; Wed, 09 Jun 2021 11:00:24 -0400 X-MC-Unique: eJ6lviPIMnWCxcg8T7Wt7Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7690919611B5; Wed, 9 Jun 2021 15:00:23 +0000 (UTC) Received: from [172.16.176.1] (ovpn-64-2.rdu2.redhat.com [10.10.64.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DDDD216558; Wed, 9 Jun 2021 15:00:22 +0000 (UTC) From: "Benjamin Coddington" To: "Trond Myklebust" Cc: mwakabayashi@vmware.com, linux-nfs@vger.kernel.org, aglo@umich.edu, SteveD@redhat.com Subject: Re: NFSv4: Mounting NFS server which is down, blocks all other NFS mounts on same machine Date: Wed, 09 Jun 2021 11:00:21 -0400 Message-ID: <443A6C4D-28EC-4866-B464-6B04EAF1CF4D@redhat.com> In-Reply-To: <752114495b47624b022bb7de366c6b1771d0599a.camel@hammerspace.com> References: <6ae47edc-2d47-df9a-515a-be327a20131d@RedHat.com> <43b719c36652cdaf110a50c84154fca54498e772.camel@hammerspace.com> <752114495b47624b022bb7de366c6b1771d0599a.camel@hammerspace.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On 9 Jun 2021, at 10:41, Trond Myklebust wrote: > On Wed, 2021-06-09 at 10:31 -0400, Benjamin Coddington wrote: >> >> It's not disputed that mounts waiting on the transport layer will block >> other mounts. >> >> It might be able to be changed:  there's this torch: >> https://lore.kernel.org/linux-nfs/87378omld4.fsf@notabene.neil.brown.name/ >> > > No. > >> ..or there may be another way we don't have to wait .. >> > > OK. So let's look at how we can solve the problem of the initial > connection to the server timing out and causing hangs in > nfs41_walk_client_list(), and leave aside any other corner case > problems (such as the server going down while we're mounting). > > How about something like the following (compile tested only) patch? It works as intended for this case, but I don't have my head wrapped around the implications of the change yet. Ben