From owner-freebsd-fs@freebsd.org Tue Nov 8 00:22:11 2016 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B978EC35756 for ; Tue, 8 Nov 2016 00:22:11 +0000 (UTC) (envelope-from 01000158414cc5c5-970a3199-02b0-410a-97ce-6000b4c46050-000000@amazonses.com) Received: from a8-13.smtp-out.amazonses.com (a8-13.smtp-out.amazonses.com [54.240.8.13]) (using TLSv1 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 7C749970 for ; Tue, 8 Nov 2016 00:22:11 +0000 (UTC) (envelope-from 01000158414cc5c5-970a3199-02b0-410a-97ce-6000b4c46050-000000@amazonses.com) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=vnqrkfnvu6csdl6mwgk5t6ix3nnepx57; d=tarsnap.com; t=1478564300; h=Subject:To:References:From:Message-ID:Date:MIME-Version:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=rx624prAR5kyv/feQZS9yEt5oMnFmLgG1ixjSola4fE=; b=GwZghch25G3JfcQwLCCijrDrSNuVkaqAs96p+zkr+zzKA08GRnxBaByv/Eapq/hp cTxbrn+sWIV6LGIVnLGJet6ftf1fBhCEliN5ffw35dJ5I54D5ExuMyJSWP99A9AoVnI 9CmrVFrynBVFktBJ5qgmqFCmgD9dtCuYKP6M2Tg0= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=6gbrjpgwjskckoa6a5zn6fwqkn67xbtw; d=amazonses.com; t=1478564300; h=Subject:To:References:From:Message-ID:Date:MIME-Version:In-Reply-To:Content-Type:Content-Transfer-Encoding:Feedback-ID; bh=rx624prAR5kyv/feQZS9yEt5oMnFmLgG1ixjSola4fE=; b=hZWOXjd/d9R7Blj9yl4jVGId8T5s3j7YauhRto5n32vASWP2z1e9E6pnggbJJjIf nhDTxQmkzJAcxUmZNud339AzWs87h+QYtfSyixIcxdF8dMIuzerkb5ckdOwLi3IcuG2 1LIAZAPmXUGmYnfSD0A/y2FvdGGUbIfkd51cKTrc= Subject: Re: Mount protocol/showmount vs NFSv4 To: Rick Macklem , "freebsd-fs@freebsd.org" References: <0100015840bc8135-cc77751d-68f4-48de-af77-b09327d24a0d-000000@email.amazonses.com> From: Colin Percival Message-ID: <01000158414cc5c5-970a3199-02b0-410a-97ce-6000b4c46050-000000@email.amazonses.com> Date: Tue, 8 Nov 2016 00:18:20 +0000 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SES-Outgoing: 2016.11.08-54.240.8.13 Feedback-ID: 1.us-east-1.Lv9FVjaNvvR5llaqfLoOVbo2VxOELl7cjN0AOyXnPlk=:AmazonSES X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Nov 2016 00:22:11 -0000 On 11/07/16 14:12, Rick Macklem wrote: > Colin Percival wrote: >> On 11/06/16 12:51, Rick Macklem wrote: >>> I have never done anything about this, since most were still using NFSv3, but it seems >>> that maybe something should be done now? >>> - What do people think of having a new option on mountd(8) that would be used for >>> NFSv4 only servers that disables servicing of Mount RPCs. >> >> Done in isolation, it seems that this would guarantee that unmounting an >> nfsv4 filesystem will result in umount(8) hanging while it waits for >> responses to the UDP packets it sends. So I'd think that we should fix >> the client side to stop sending those first? > Yes, the NFSv4 client should be fixed so that it doesn't do Unmount RPCs before > mountd gets changed. (I had thought of this, but neglected to mention it in the first > post. Thanks for bringing this up.) I was thinking more in terms of time line -- presumably there will be some people running older FreeBSD clients connecting to newer FreeBSD servers. Should we wait some time between fixing the nfsv4 client and when we turn off RPC handling in the mountd server? (And if yes, how long?) -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid