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 q7N548qT135553 for ; Thu, 23 Aug 2012 00:04:08 -0500 Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id 38rMSZzMi8d1HpGz for ; Wed, 22 Aug 2012 22:04:54 -0700 (PDT) Received: from disappointment ([192.168.1.1]) by dastard with esmtp (Exim 4.76) (envelope-from ) id 1T4Pb9-0003IL-SS for xfs@oss.sgi.com; Thu, 23 Aug 2012 15:04:51 +1000 Received: from dave by disappointment with local (Exim 4.80) (envelope-from ) id 1T4Paz-0003gS-Ot for xfs@oss.sgi.com; Thu, 23 Aug 2012 15:04:41 +1000 From: Dave Chinner Subject: [PATCH 063/102] xfs: Account log unmount transaction correctly Date: Thu, 23 Aug 2012 15:02:21 +1000 Message-Id: <1345698180-13612-64-git-send-email-david@fromorbit.com> In-Reply-To: <1345698180-13612-1-git-send-email-david@fromorbit.com> References: <1345698180-13612-1-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 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: xfs@oss.sgi.com From: Dave Chinner Upstream commit: 3948659e30808fbaa7673bbe89de2ae9769e20a7 There have been a few reports of this warning appearing recently: XFS (dm-4): xlog_space_left: head behind tail tail_cycle = 129, tail_bytes = 20163072 GH cycle = 129, GH bytes = 20162880 The common cause appears to be lots of freeze and unfreeze cycles, and the output from the warnings indicates that we are leaking around 8 bytes of log space per freeze/unfreeze cycle. When we freeze the filesystem, we write an unmount record and that uses xlog_write directly - a special type of transaction, effectively. What it doesn't do, however, is correctly account for the log space it uses. The unmount record writes an 8 byte structure with a special magic number into the log, and the space this consumes is not accounted for in the log ticket tracking the operation. Hence we leak 8 bytes every unmount record that is written. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Ben Myers --- fs/xfs/xfs_log.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index d92b442..653cba8 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -726,8 +726,9 @@ xfs_log_unmount_write(xfs_mount_t *mp) .lv_iovecp = ®, }; - /* remove inited flag */ + /* remove inited flag, and account for space used */ tic->t_flags = 0; + tic->t_curr_res -= sizeof(magic); error = xlog_write(log, &vec, tic, &lsn, NULL, XLOG_UNMOUNT_TRANS); /* -- 1.7.10 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs