From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 q0BBYVUb161426 for ; Wed, 11 Jan 2012 05:34:31 -0600 Date: Wed, 11 Jan 2012 06:34:28 -0500 From: Christoph Hellwig Subject: Re: [PATCH 1/1] xfs: serialise unaligned direct IOs Message-ID: <20120111113428.GA14423@infradead.org> References: <1325845990-5664-1-git-send-email-amit.sahrawat83@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1325845990-5664-1-git-send-email-amit.sahrawat83@gmail.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Amit Sahrawat Cc: Christoph Hellwig , xfs masters , xfs , linux kernel , Alex Elder > + /* > + * In most cases the direct IO writes will be done with IOLOCK_SHARED > + * allowing them to be done in parallel with reads and other direct IO > + * writes. However,if the IO is not aligned to filesystem blocks, the > + * direct IO layer needs to do sub-block zeroing and that requires > + * serialisation against other direct IOs to the same block. In this > + * case we need to serialise the submission of the unaligned IOs so > + * that we don't get racing block zeroing in the dio layer. > + * To avoid the problem with aio, we also need to wait for outstanding > + * IOs to complete so that unwritten extent conversion is completed > + * before we try to map the overlapping block. This is currently > + * implemented by hitting it with a big hammer (i.e. xfs_ioend_wait()). > + */ > + This comment is lacking one level of indentation, that's because the old kernel is missing the split of xfs_file_aio_write that reduces one level of indentation. Otherwise the backport looks fine, please send it to stable@vger.kernel.org, with a [PATCH 0/0] coverletter stating it's for 2.6.35-stable. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs