From owner-svn-src-head@freebsd.org Tue Nov 7 15:21:58 2017 Return-Path: Delivered-To: svn-src-head@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 49E25E5BA3A; Tue, 7 Nov 2017 15:21:58 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-lf0-x229.google.com (mail-lf0-x229.google.com [IPv6:2a00:1450:4010:c07::229]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C281E6E516; Tue, 7 Nov 2017 15:21:57 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-lf0-x229.google.com with SMTP id a132so14922530lfa.7; Tue, 07 Nov 2017 07:21:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=bKP9qgP2U4CiRboPV2SODMLgEbWJOdu3MUue17LqSw8=; b=qeqmaNmHR+ObKkv+48eyb4Ikic9EAD2NsWzk0PQfd2Ma1Vo6fyPOUq+oVFGhUJnCVn 7kPVsZByeUPQ2VlsDhY73NW6o2NCeiKeHakZGz0iMXP8KDcNrjZvHE+oZQLakYbS3hUt ac5JMp4wfzyKQznmtWXrRf2Pc8YmCnxzi+xWidInNPQi+v1kOwb99rcXPx+JHxqcRyfi kloDCtEckb3wnQviit5uhQNP3c6w+9O8bfNaIoEVGj2/MuCrqrrV+aZ5REM1yHCZe9Bg kJBAamUKNAKflr5/LJ5aLzSXkwlePw7OkxsvpKLzFf0TfSKIzRmCTyspFkDWe0EkN1Sd rt5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=bKP9qgP2U4CiRboPV2SODMLgEbWJOdu3MUue17LqSw8=; b=hmcBTjoa9j/Ia1T8FXZCCuexjsznY0tlhCq3qULtithP7TaFACCxRVEb/AxE5hZpxj LUq5LmYHdSzYbfb34CXjF9OaPWSkuIuxJHuWp8J/J39IPEnRsZXbNu47lOCLYfweJ9Pf Tmex89NsW0JXcj94vj+NBi0n2GtYVJcbhkyvBe4CFiig/RFOvUks1e628LFFxKiLieQG qtbzV/QAqveYamy5/lam/1pjvu73H43IzZX+1mfJcKnhYDkiWH/iPKECo8tkUwc3bizN B+ipRrXFuT6KVWXBrpVTrhWPeTS8rv/diHdDw0uvg6u2pDQOyWtEirhVvlX5DugJsk4i Ykbg== X-Gm-Message-State: AJaThX5gvXiiDLR804YU2kgt3uRfhoz+tbgR2vOefq8QSOfcMqKtSRi2 ujJTjxoWL/ecuvCdoPukknljDvsBQJJ9Ro4DXDc= X-Google-Smtp-Source: ABhQp+Ra15MBEOEyF1h0vGZ8/vtMrhO8TtoULsebYIbOl5qCDnetQg9EVf7HRpIlbyWtj6d1ZbmHqOFhL9b9Hw5WrVU= X-Received: by 10.46.88.73 with SMTP id x9mr2779052ljd.80.1510068115478; Tue, 07 Nov 2017 07:21:55 -0800 (PST) MIME-Version: 1.0 Sender: asomers@gmail.com Received: by 10.179.93.24 with HTTP; Tue, 7 Nov 2017 07:21:54 -0800 (PST) In-Reply-To: <201711041438.vA4Ec0vx097305@repo.freebsd.org> References: <201711041438.vA4Ec0vx097305@repo.freebsd.org> From: Alan Somers Date: Tue, 7 Nov 2017 08:21:54 -0700 X-Google-Sender-Auth: paW7ZUbKOf__jKqgqWNeqIzNpUQ Message-ID: Subject: Re: svn commit: r325392 - head/etc/autofs To: Edward Tomasz Napierala Cc: "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Nov 2017 15:21:58 -0000 On Sat, Nov 4, 2017 at 8:38 AM, Edward Tomasz Napierala wrote: > Author: trasz > Date: Sat Nov 4 14:38:00 2017 > New Revision: 325392 > URL: https://svnweb.freebsd.org/changeset/base/325392 > > Log: > Add NIS automounter map, which supports rewriting of self-hosted locations > to make them nullfs. > > PR: 221010 > Submitted by: G. Paul Ziemba > MFC after: 2 weeks This is not generally safe with NFSv4. If vfs.nfsd.issue_delegations==1, then the server will allow NFS clients to delay flushing writes back to the server. The protocol handles multiple clients that want delegations for the same file, but it doesn't handle local access. So if somebody tries to automount a locally-hosted NFSv4 volume with delegations enabled, but accidentally mounts it with nullfs instead, file corruption could result. The simplest solution would be to never use nullfs if vfs.nfsd.issue_delgations==1. -Alan