From owner-svn-src-all@FreeBSD.ORG Thu Nov 14 09:51:21 2013 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id B12B5C08 for ; Thu, 14 Nov 2013 09:51:21 +0000 (UTC) Received: from o3.shared.sendgrid.net (o3.shared.sendgrid.net [208.117.48.85]) by mx1.freebsd.org (Postfix) with SMTP id 4A4842B89 for ; Thu, 14 Nov 2013 09:51:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sendgrid.info; h=from:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; s=smtpapi; bh=65aUa31MBPq/AQ1HRz4W6z5j8GE=; b=RtpSPku6roduFJblNh Ao6IpFJWhh5Y1oeZsA3jLvSg1dFrQKjwB+7XpReHTAjsK+fzOJJu6SqwWNZTkb33 ev4TQZsb0RBuJHqxZgRVOR9HiYn+8GDinqU8J1+dHbS3izW2Ecr06uhMsCjD0FG5 n5PLVbkmsg5MZHDiBjecbnS5s= Received: by mf20.sendgrid.net with SMTP id mf20.664.52849D133 Thu, 14 Nov 2013 09:51:15 +0000 (GMT) Received: from mail.tarsnap.com (unknown [10.60.208.13]) by mi37 (SG) with ESMTP id 142560592d3.288a.b1369a for ; Thu, 14 Nov 2013 03:51:15 -0600 (CST) Received: (qmail 58027 invoked from network); 14 Nov 2013 09:51:14 -0000 Received: from unknown (HELO clamshell.daemonology.net) (127.0.0.1) by ec2-107-20-205-189.compute-1.amazonaws.com with ESMTP; 14 Nov 2013 09:51:14 -0000 Received: (qmail 39560 invoked from network); 14 Nov 2013 09:49:07 -0000 Received: from unknown (HELO clamshell.daemonology.net) (127.0.0.1) by clamshell.daemonology.net with SMTP; 14 Nov 2013 09:49:07 -0000 Message-ID: <52849C93.5010500@freebsd.org> Date: Thu, 14 Nov 2013 01:49:07 -0800 From: Colin Percival User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Robert Watson Subject: Re: svn commit: r258124 - head/usr.sbin/portsnap/portsnap References: <201311140922.rAE9MW39043456@svn.freebsd.org> In-Reply-To: X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SG-EID: A6W2xSVPHetogaU8rnzccWwgBYtN+QvIzXyjfe/10PFGEIPYJiiBTfs3V4AmhqJwQ3oqutrhXsnDRsGDZbsDLMR2AOuabbSakPm13Gbrnau7NYP4jFDUyO5FJnFAezyxpYtVoTHaLHT8uTM2p9fuMxoxjsdUYHbt9g7rZgUu3NA= Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Nov 2013 09:51:21 -0000 On 11/14/13 01:47, Robert Watson wrote: > On Thu, 14 Nov 2013, Colin Percival wrote: >> When verifying that files we need are present, also check that they don't >> have zero length. Filesystem corruption will tend to truncate files, and >> since these are short that's likely to result in them becoming empty. > > I think I'd probably express this slightly differently: the filesystem isn't > corrupted, it just doesn't contain the data you expect. As filesystems don't > guarantee data is there until fsync() has returned, it is actually meeting all > its promises -- e.g., vs corrupted inode contents due to a filesystem bug. True, I should have written "crashes resulting in data loss". -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid