From owner-svn-src-head@FreeBSD.ORG Thu Apr 28 16:10:55 2011 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 79DCB1065674 for ; Thu, 28 Apr 2011 16:10:55 +0000 (UTC) (envelope-from giffunip@yahoo.com) Received: from nm10.bullet.mail.sp2.yahoo.com (nm10.bullet.mail.sp2.yahoo.com [98.139.91.80]) by mx1.freebsd.org (Postfix) with SMTP id 3E0888FC29 for ; Thu, 28 Apr 2011 16:10:55 +0000 (UTC) Received: from [98.139.91.62] by nm10.bullet.mail.sp2.yahoo.com with NNFMP; 28 Apr 2011 15:57:53 -0000 Received: from [98.139.91.19] by tm2.bullet.mail.sp2.yahoo.com with NNFMP; 28 Apr 2011 15:57:53 -0000 Received: from [127.0.0.1] by omp1019.mail.sp2.yahoo.com with NNFMP; 28 Apr 2011 15:57:53 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 711827.74135.bm@omp1019.mail.sp2.yahoo.com Received: (qmail 12188 invoked by uid 60001); 28 Apr 2011 15:57:53 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1304006273; bh=BiLKaJe8YkBuTs24ti0Tt9CxFYOg0v6HWAgR+DiQB4o=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:MIME-Version:Content-Type; b=ABlAil0y7kg5lLM8+Xk7thZrTtjMA/YwjG0TF3xc/733+V5O8of5u0GVMTqumK7TUGHURpg7w7dAmAp6jMKfDCFcvmyUG6jvXGhinu7lbVA5IMvqtEIxNYleVMedeFZhtL+O88ieBKsyu2rD/6BpCbC3opl9/PVB3ee/Udu8fEM= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:MIME-Version:Content-Type; b=Z/6XnxB8U2XvS/oBHzII1yVQGXg8mnCeT+kaOykW8On/vWrB5fuzkmB3hVFwGz+WPIN84N6B4peYc4vGrPD4BUjKYV7clYvswSLYc4kHKh+eUkjiI8Zf5o+G5JPRAqhulp9yAeCfVSqCKRxv8exU9pDsk6FHdOIj2AVnPM5RAyo=; Message-ID: <433267.83376.qm@web113513.mail.gq1.yahoo.com> X-YMail-OSG: x7fE44MVM1kaWt9iRLhDWo.qkfp5rHfZCDsE9W0UIS1J0hi U90KY93YOafxSh2IDuvIk5m3YCUVEQvilq1.K4cGB_93VLBV0Sss92L3us91 rMXiskNut2dm_sPneQVrWPleXVrhQTfgwRUpZ1RmabmaCX0mjo_KakrtfnM9 oPQ2uUUjjrQblyoySrut_kVqJ8MBHkuKu8s_eCYMw9N_ungtHWzdWGjKqNsw lVvrXvsPc.iPRPr3KlO6hyrSjwEW1nCuC6yqnneuhdiib.pXYn8GyslUSvtM LhjmSEryl_CdYDYGiGh8aMivbm7Nt5YKQaC6aFr.N2zwN8YsDUh1PvELaCBn A7l8i2AG5IxxBQxfONQbFUv_yslV2OCOzORnnRjeow6MfLuIKjXeDJAps.3d hJQeesbJnaIFs Received: from [190.157.141.135] by web113513.mail.gq1.yahoo.com via HTTP; Thu, 28 Apr 2011 08:57:53 PDT X-Mailer: YahooMailClassic/12.0.2 YahooMailWebService/0.8.110.299900 Date: Thu, 28 Apr 2011 08:57:53 -0700 (PDT) From: "Pedro F. Giffuni" To: Kostik Belousov MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: svn-src-head@freebsd.org, John Baldwin Subject: Re: svn commit: r221166 - in head/sys: fs/ext2fs modules/ext2fs X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 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: Thu, 28 Apr 2011 16:10:55 -0000 > There is no dependencies for ext2fs, the FFS comments talks about SU. You are right ... I will have to clean that up. It was not easy to keep all SU stuff from getting in. > Also, I am unsure what the resulting semantic of O_DIRECTIO for ext2 > is ? UFS tries to eliminate any use of buffer cache for O_DIRECTIO > case, up to the mapping of user pages into pbuf to perform the > actual i/o. In ext2 case, it seems we will just destroy the buffers > after using them for i/o. Is it useful ? We do not support the complete direct_io stuff (not even in UFS). In ext2fs we are only avoiding double caching: it is assumed that the application (usually databases) knows why it's setting O_DIRECTIO and do their own caching. From what I discussed with Tor Egge it is useful. cheers, Pedro.