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 q6ODvxHJ118516 for ; Tue, 24 Jul 2012 08:57:59 -0500 Date: Tue, 24 Jul 2012 09:57:58 -0400 From: Christoph Hellwig Subject: Re: [RFC] xfs: wait for the write of the superblock on unmount Message-ID: <20120724135758.GA6564@infradead.org> References: <20120717215957.855744999@tinguelysgi.com> <20120718220003.396849822@tinguelysgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120718220003.396849822@tinguelysgi.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: tinguely@sgi.com Cc: xfs@oss.sgi.com On Wed, Jul 18, 2012 at 12:33:58PM -0500, tinguely@sgi.com wrote: > Sorry, I have been distracted away from this regression. This was previously > titled "xfs: synchronously write the superblock on unmount". > > xfs_wait_buftarg() does not wait for the completion of the write of the > uncached superblock. This write can race with the shutdown of the log and > causes a panic if the write does not win the race. > > The log write of the superblock is important for possible recovery, but a > second syncronous write of the same superblock seems redundant. Would just > waiting for the iodone() of the log write before tearing down the log be > enough? This doesn't look beautiful, but I suspect there's no good way around it. Can you add your explanation from the reply on why xfs_buf_iowait does not work here to the comment above the lock/unlock pair? With that: Reviewed-by: Christoph Hellwig _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs