From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q6V0DR4q110777 for ; Mon, 30 Jul 2012 19:13:27 -0500 Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id 2TF2ICT3mWEeF2En for ; Mon, 30 Jul 2012 17:13:25 -0700 (PDT) Date: Tue, 31 Jul 2012 10:13:22 +1000 From: Dave Chinner Subject: Re: [PATCH v5 4/4]xfs: xfs_seek_hole() refinements with lookup hole offset from page cache. Message-ID: <20120731001322.GN2877@dastard> References: <50110636.2010602@oracle.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <50110636.2010602@oracle.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: Jeff Liu Cc: xfs@oss.sgi.com On Thu, Jul 26, 2012 at 04:56:22PM +0800, Jeff Liu wrote: > Search possbile hole offset for given range from page cache for unwritten and delayed-allocation extents. > > Signed-off-by: Jie Liu > Reviewed-by: Mark Tinguely > Reviewed-by: Christoph Hellwig > Reviewed-by: Dave Chinner > > --- > fs/xfs/xfs_file.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++------ > 1 files changed, 80 insertions(+), 10 deletions(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 15acd4d..1b83549 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -1296,9 +1296,9 @@ xfs_seek_hole( > struct xfs_inode *ip = XFS_I(inode); > struct xfs_mount *mp = ip->i_mount; > loff_t uninitialized_var(offset); > - loff_t holeoff; > xfs_fsize_t isize; > xfs_fileoff_t fsbno; > + xfs_filblks_t end; > uint lock; > int error; > > @@ -1314,20 +1314,90 @@ xfs_seek_hole( > } > > fsbno = XFS_B_TO_FSBT(mp, start); > - error = xfs_bmap_first_unused(NULL, ip, 1, &fsbno, XFS_DATA_FORK); > - if (error) > - goto out_unlock; > + end = XFS_B_TO_FSB(mp, isize); > + > + for (;;) { > + struct xfs_bmbt_irec map[2]; > + int nmap = 2; > + > + error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap, > + XFS_BMAPI_ENTIRE); > + if (error) > + goto out_unlock; > + > + /* No extents at given offset, must be beyond EOF */ > + if (nmap == 0) { > + error = ENXIO; > + goto out_unlock; > + } > > - holeoff = XFS_FSB_TO_B(mp, fsbno); > - if (holeoff <= start) > offset = start; > - else { > + /* Landed in a hole, return */ > + if (map[0].br_startblock == HOLESTARTBLOCK) > + break; > + else { > + /* > + * Landed in an unwritten extent, try to lookup page > + * cache to find holes. > + */ Laned in a data extent is more correct here. > + if (map[0].br_state == XFS_EXT_UNWRITTEN || > + isnullstartblock(map[0].br_startblock)) { > + /* Probing page cache start from offset */ > + if (xfs_find_get_desired_pgoff(inode, &map[0], > + HOLE_OFF, &offset)) > + break; > + } Same logic changes as previous patch: if (map[0].br_startblock == HOLESTARTBLOCK) break; else if (map[0].br_state == XFS_EXT_UNWRITTEN) { ASSERT(!isnullstartblock(map[0].br_startblock)); /* Probing page cache start from offset */ if (xfs_find_get_desired_pgoff(inode, &map[0], HOLE_OFF, &offset)) break; } else { ..... > /* > - * xfs_bmap_first_unused() could return a value bigger than > - * isize if there are no more holes past the supplied offset. > + * Both mappings contains data, proceed to the next round of > + * search if the current reading offset not beyond or hit EOF. > */ > - offset = min_t(loff_t, holeoff, isize); > + fsbno = map[1].br_startoff + map[1].br_blockcount; > + start = XFS_FSB_TO_B(mp, fsbno); > + if (start >= isize) { > + offset = isize; > + break; > + } And that check can move to the start of the loop, too. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs