From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sunil Mushran Subject: Re: [Ocfs2-devel] [PATCH] ocfs2: Implement llseek() Date: Thu, 19 May 2011 10:29:08 -0700 Message-ID: <4DD55364.8070002@oracle.com> References: <1305773084-19296-1-git-send-email-sunil.mushran@oracle.com> <1305773084-19296-3-git-send-email-sunil.mushran@oracle.com> <20110519110531.GB6357@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: josef@redhat.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, viro@ZenIV.linux.org.uk, ocfs2-devel@oss.oracle.com To: Christoph Hellwig Return-path: In-Reply-To: <20110519110531.GB6357@lst.de> List-ID: On 05/19/2011 04:05 AM, Christoph Hellwig wrote: > On Wed, May 18, 2011 at 07:44:44PM -0700, Sunil Mushran wrote: >> Unwritten (preallocated) extents are considered holes because the file system >> treats reads to such regions in the same way as it does to holes. > How does this work for the case of an unwrittent extent that has been > written to in the pagecache but not converted yet? Y'know the big data > corruption and flamewar that started all this? We don't delay splitting the extent. It is split in ->write_begin(). Delaying it will be a challenge as we have to provide cache coherency across the cluster. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sunil Mushran Date: Thu, 19 May 2011 10:29:08 -0700 Subject: [Ocfs2-devel] [PATCH] ocfs2: Implement llseek() In-Reply-To: <20110519110531.GB6357@lst.de> References: <1305773084-19296-1-git-send-email-sunil.mushran@oracle.com> <1305773084-19296-3-git-send-email-sunil.mushran@oracle.com> <20110519110531.GB6357@lst.de> Message-ID: <4DD55364.8070002@oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig Cc: josef@redhat.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, viro@ZenIV.linux.org.uk, ocfs2-devel@oss.oracle.com On 05/19/2011 04:05 AM, Christoph Hellwig wrote: > On Wed, May 18, 2011 at 07:44:44PM -0700, Sunil Mushran wrote: >> Unwritten (preallocated) extents are considered holes because the file system >> treats reads to such regions in the same way as it does to holes. > How does this work for the case of an unwrittent extent that has been > written to in the pagecache but not converted yet? Y'know the big data > corruption and flamewar that started all this? We don't delay splitting the extent. It is split in ->write_begin(). Delaying it will be a challenge as we have to provide cache coherency across the cluster.