From owner-freebsd-fs@freebsd.org Tue Jun 4 00:44:14 2019 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 881A115C2A57 for ; Tue, 4 Jun 2019 00:44:14 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-lf1-f65.google.com (mail-lf1-f65.google.com [209.85.167.65]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 8A12C77332 for ; Tue, 4 Jun 2019 00:44:13 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-lf1-f65.google.com with SMTP id u10so7993986lfm.12 for ; Mon, 03 Jun 2019 17:44:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4kTTZxKA5JOi7VZ68fZCUyGvtUZlVZm9QjJviv5nxgE=; b=L2tA1LgTqvgPOOVr1FaZASGGalAGgRVTgNCGerfjOB2LT26Skm9RmGrpo21uj4jrXq 1F/oWP/EV/wLRJkdiFT9dQd6lmJhNHzcG3V8U76Bm6bQRfTQ7AS4fy9gxNBoHjAWa4As NcpMFPn4yyQtAUTNbW6cGdhlvbKmGBN80rqt4miezbo0tCQmkuqlEmL0kR3Cub5RAKRz RKFCPUXW05AtjN41PYUOVV54h+lPCgBm6EJn6VLvODbogOInNwEraRkAfpVpwRb1waxL o5bLI8D1JPkW9beOzYqztSAggUH/LHXM0Rc5kPcgvWSCwlJpn98Qq+ePre55Pv/RsKEy 0Nhw== X-Gm-Message-State: APjAAAXohFDpIMuYW0vxI03N/BzL/Kme1MI1dKSm5sNethXrVqsjOdM5 UqCNQUdnxxEqPZs0HWXesgA5qhM+sEKKiFVUpVs= X-Google-Smtp-Source: APXvYqzlDBRcXWfQnT3EcbpVknlKs9n+Fd03wvzS65NG3UK2ULnpoOMIjLjGAWsdATejc1w43+2nz0EGHoYOEZKmkwU= X-Received: by 2002:a19:671c:: with SMTP id b28mr14962859lfc.164.1559609045951; Mon, 03 Jun 2019 17:44:05 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Alan Somers Date: Mon, 3 Jun 2019 18:43:54 -0600 Message-ID: Subject: Re: RFC: should an incremental reload of exports for mountd be optional? To: Rick Macklem Cc: Peter Eriksson , "freebsd-fs@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 8A12C77332 X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of asomers@gmail.com designates 209.85.167.65 as permitted sender) smtp.mailfrom=asomers@gmail.com X-Spamd-Result: default: False [-3.20 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; NEURAL_HAM_SHORT(-0.94)[-0.936,0]; FORGED_SENDER(0.30)[asomers@freebsd.org,asomers@gmail.com]; IP_SCORE(-1.25)[ip: (-0.54), ipnet: 209.85.128.0/17(-3.39), asn: 15169(-2.29), country: US(-0.06)]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[asomers@freebsd.org,asomers@gmail.com]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; SUBJECT_ENDS_QUESTION(1.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-fs@freebsd.org]; DMARC_NA(0.00)[freebsd.org]; MIME_TRACE(0.00)[0:+]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[65.167.85.209.list.dnswl.org : 127.0.5.0]; RCVD_TLS_LAST(0.00)[]; RWL_MAILSPIKE_POSSIBLE(0.00)[65.167.85.209.rep.mailspike.net : 127.0.0.17]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Jun 2019 00:44:14 -0000 On Mon, Jun 3, 2019 at 6:30 PM Rick Macklem wrote: > > Alan Somers wrote: > >Will a restart of the daemon cause clients to get HUPped if they try > >to access an exported filesystem while mountd is restarting? > >-Alan > I'm not sure what you mean by HUPped, but during a restart of mountd, extant > mounts should continue to work. Perhaps it wasn't SIGHUP, but I recall that a few years ago there was a problem where all NFS I/O would fail while mountd was reloading. I think it's the problem that you fixed in r241568. > > What will fail during the mountd restart is new NFSv3 mount attempts, because > they won't be able to talk to mountd via the Mount protocol. Usually the > failure will be rpcbind not having MOUNTPROG registered. > Then a retry of the mount (which will happen after something like 30sec if you > don't C the mount command) will succeed, assuming mountd has restarted. > Unmounts will complain the MOUNTPROG wasn't registered, but the umount > will work anyhow. > > Then "showmount", which is never guaranteed to return correct info, will report it > as still mounted. Since "showmount" never knows about NFSv4 mounts and just > returns its guess at what is mounted, I don't find it useful anyhow. > > NFSv4 mounts should continue to work when mountd isn't running, since they don't use the Mount protocol. And, since they don't use the Mount protocol, "showmount" > never knows about them. > > So, I restart can cause some disruption, but they are mostly just delays when doing > new NFSv3 mounts on the server. > > rick > > On Mon, Jun 3, 2019 at 5:13 PM Rick Macklem wrote: > > > > Thanks everyone for your comments. I just committed the patch with > > the incremental reload of exports always enabled. > > If people run into problems, I can add some "backdoor" way to disable > > it, as suggested by asomers@. > > > > A restart of the daemon will always do a full reload to work around any > > reload failures. > > > > rick > > > [stuff snipped]