From owner-svn-src-head@freebsd.org Sat Dec 9 22:37:21 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 4D465E9A81F; Sat, 9 Dec 2017 22:37:21 +0000 (UTC) (envelope-from markjdb@gmail.com) Received: from mail-pl0-x229.google.com (mail-pl0-x229.google.com [IPv6:2607:f8b0:400e:c01::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 23DBB78657; Sat, 9 Dec 2017 22:37:21 +0000 (UTC) (envelope-from markjdb@gmail.com) Received: by mail-pl0-x229.google.com with SMTP id bi12so2396598plb.6; Sat, 09 Dec 2017 14:37:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=4PwKbYAiJckZX90JaiYl45zfE2I2ve4kC++aJSHo5qY=; b=HBeH8girLvaBE+UlQM/tXFxRZO8cY5UcaBrTgl87G180itpiq3Hw2qcnoJomncyH79 jltSvirgHJX26ojchVhCyMva7ktCxb47N6NU7pqCFaCEagxQOxnjYhQhhjQPMTGlkIQo hXgDzmfAOuX7BJUz4Gy8Qp+Di/NhD4zO875qrXgkzK6c21126YMBKV4BQ1OubbmMI0Rr ENZjJdYoWTkiaF3Wm42DUbTTDR0HxtmX2JL+avq/ep19me7U/EmAi+PEGHfddmIstC8q p7JMPphwCKh89YTwWfLtYXTpgFBeDKRK3Qxqulv1V5MGzAbxo1Hb2iaE0rkYQmrjlwxQ bZ7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=4PwKbYAiJckZX90JaiYl45zfE2I2ve4kC++aJSHo5qY=; b=p6h4hTSICnWQT3/jZkqrCS+c7xc4Q/DU5z0/tVJtKc+CJ8DhQMECkYRL3vcTJeHmZL e8lHOkET9fkY0BRKC4Y74op1RO/YdnSKhwPr+HLgisGgG4f2Lz7ZShlO27cI3cQbtjPb D8YYR0ru00Cgy4AsFrOglo/+t2gteNJehaei/vVtT7GOozHEfriBF9popl/zLT5c6sx7 D67CrO9MVZnoIFABYm4oJcrkswn55thE5hjzvrIgAKw3L8kBPpqf3qg7EHhlN3/gsNnM vY9Sn14IZUHBUq6ZF+GuGac00MXSMle40azTDVv0kra0ncHpP72I1CnqVIRTX9Jazjw+ lyLw== X-Gm-Message-State: AJaThX7YRY6Sjzihpt9zy7qEH8Y2TnLkFXYx9BsldYV8jCmIWVBVoJAy tc7iWYgzKd439lo4uBsLHPmbCw== X-Google-Smtp-Source: AGs4zMZohnkhnwk9benYGwbaHtP5ravhuMuDzBNLM3QNnDbUb41fKPZpAOFhdGl6t8I8Syrve9n+0A== X-Received: by 10.84.240.193 with SMTP id l1mr34684251plt.240.1512859039835; Sat, 09 Dec 2017 14:37:19 -0800 (PST) Received: from raichu (toroon0560w-lp140-01-69-159-38-22.dsl.bell.ca. [69.159.38.22]) by smtp.gmail.com with ESMTPSA id i11sm18126361pfk.25.2017.12.09.14.37.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 09 Dec 2017 14:37:18 -0800 (PST) Sender: Mark Johnston Date: Sat, 9 Dec 2017 17:37:13 -0500 From: Mark Johnston To: Andriy Gapon Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r326731 - head/sys/ufs/ffs Message-ID: <20171209223713.GA15275@raichu> References: <201712091544.vB9FiVUI096790@repo.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.25 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: Sat, 09 Dec 2017 22:37:21 -0000 On Sat, Dec 09, 2017 at 08:03:37PM +0200, Andriy Gapon wrote: > On 09/12/2017 17:44, Mark Johnston wrote: > > Some GEOMs do not appear to handle BIO_ORDERED correctly, meaning that the > > Nitpick: this should be "geoms" or, even better, "GEOM classes" :-) Ok. :) > > barrier write may not work as intended. > Could the loss of BIO_ORDERED in g_duplicate_bio() contribute to the problem > with those GEOM classes? It does look like a bug that g_duplicate_bio() doesn't preserve that flag. However, the issue I was looking at was in gmirror: when a mirror is being synchronized, gmirror will delay writes that collide with an active synchronization request. However, subsequent writes which do not collide are passed directly to the mirrors, so an ordering violation is possible. I plan to fix this. I haven't checked, but graid might have a similar issue. I also noticed that gsched doesn't take BIO_ORDERED into account when sorting requests. Isilon has an I/O scheduler which has this problem too.