X-Spam-Checker-Version: SpamAssassin 3.4.0-r929098 (2010-03-30) on oss.sgi.com X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham version=3.4.0-r929098 Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o6R7uRAQ173419 for ; Tue, 27 Jul 2010 02:56:27 -0500 X-ASG-Debug-ID: 1280218011-01fd01f40000-NocioJ X-Barracuda-URL: http://cuda.sgi.com:80/cgi-bin/mark.cgi Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 72D0E132FC6E for ; Tue, 27 Jul 2010 01:06:51 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by cuda.sgi.com with ESMTP id es1YQ5bBhZXvEZ9x for ; Tue, 27 Jul 2010 01:06:51 -0700 (PDT) X-ASG-Whitelist: Client Received: from hch by bombadil.infradead.org with local (Exim 4.72 #1 (Red Hat Linux)) id 1Odf4U-000819-V1; Tue, 27 Jul 2010 07:59:30 +0000 Date: Tue, 27 Jul 2010 03:59:30 -0400 From: Christoph Hellwig To: Dave Chinner Cc: xfs@oss.sgi.com X-ASG-Orig-Subj: Re: [PATCH 2/2] xfs: Introduce XFS_IOC_ZERO_RANGE Subject: Re: [PATCH 2/2] xfs: Introduce XFS_IOC_ZERO_RANGE Message-ID: <20100727075930.GC30562@infradead.org> References: <1280210129-10925-1-git-send-email-david@fromorbit.com> <1280210129-10925-3-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1280210129-10925-3-git-send-email-david@fromorbit.com> User-Agent: Mutt/1.5.20 (2009-08-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html X-Barracuda-Connect: bombadil.infradead.org[18.85.46.34] X-Barracuda-Start-Time: 1280218011 X-Barracuda-Virus-Scanned: by cuda.sgi.com at sgi.com X-Virus-Scanned: ClamAV version 0.94.2, clamav-milter version 0.94.2 on oss.sgi.com X-Virus-Status: Clean On Tue, Jul 27, 2010 at 03:55:29PM +1000, Dave Chinner wrote: > From: Dave Chinner > > XFS_IOC_ZERO_RANGE is the equivalent of an atomic XFS_IOC_UNRESVSP/ > XFS_IOC_RESVSP call pair. It enabled ranges of written data to be > turned into zeroes without requiring IO or having to free and > reallocate the extents in the range given as would occur if we had > to punch and then preallocate them separately. This enables > applications to zero parts of files very quickly without changing > the layout of the files in any way. This looks good minus the left over printks. It'll also needs xfstests coverage and a description in the xfsctl manpage.