From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Thu, 18 Oct 2007 09:07:35 -0700 (PDT) Received: from pentafluge.infradead.org (pentafluge.infradead.org [213.146.154.40]) by oss.sgi.com (8.12.11.20060308/8.12.10/SuSE Linux 0.7) with ESMTP id l9IG7Sah006782 for ; Thu, 18 Oct 2007 09:07:30 -0700 Date: Thu, 18 Oct 2007 16:46:49 +0100 From: Christoph Hellwig Subject: Re: review: use correct buffer flags when reading superblock Message-ID: <20071018154649.GA16837@infradead.org> References: <470C8F5B.90705@sgi.com> <20071010093451.GA7655@infradead.org> <20071010112505.GH23367404@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071010112505.GH23367404@sgi.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: David Chinner Cc: Christoph Hellwig , Lachlan McIlroy , xfs-dev , xfs-oss On Wed, Oct 10, 2007 at 09:25:06PM +1000, David Chinner wrote: > > Where are these set up in the first time? AFAICS the buffer only written > > out by xfs_unmountfs_writesb, xfs_syncsub and xfs_trans_log_buf, and all > > these should only ever happen after log recovery has finished. > > It can also be written by xfsbufd when it has been bdwrite() > or as a result of log tail pushing. Hmm, true. > Because the superblock buffer is XBF_FS_MANAGED, it does not get > torn down when it is clean and has no references, so the XBF_ASYNC > flag never gets cleared unless the fs specifically clears it. If the > superblock is then not recovered out of any further transactions > during recovery after xfsbufd flushed it, the XBF_ASYNC flag remains > set for the re-read that is issued in xlog_do_recover() and we > hang..... Makes sense as an explanation. I still don't really like patch, maybe we should always clear the ASYNC flag in the b_iodone callback?