From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 056C67F37 for ; Wed, 16 Apr 2014 01:18:42 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay1.corp.sgi.com (Postfix) with ESMTP id C5A718F8039 for ; Tue, 15 Apr 2014 23:18:38 -0700 (PDT) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id LE1ExLfccMlWi5LA for ; Tue, 15 Apr 2014 23:18:35 -0700 (PDT) Date: Wed, 16 Apr 2014 16:18:20 +1000 From: Dave Chinner Subject: Re: [PATCH 19/19] XFS: set PF_FSTRANS while ilock is held in xfs_free_eofblocks Message-ID: <20140416061819.GF15995@dastard> References: <20140416033623.10604.69237.stgit@notabene.brown> <20140416040337.10604.7488.stgit@notabene.brown> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20140416040337.10604.7488.stgit@notabene.brown> 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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: NeilBrown Cc: linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, xfs@oss.sgi.com On Wed, Apr 16, 2014 at 02:03:37PM +1000, NeilBrown wrote: > memory allocates can happen while the xfs ilock is held in > xfs_free_eofblocks, particularly > > [] kmem_zone_alloc+0x67/0xc0 > [] xfs_trans_add_item+0x25/0x50 > [] xfs_trans_ijoin+0x2c/0x60 > [] xfs_itruncate_extents+0xbe/0x400 > [] xfs_free_eofblocks+0x1c4/0x240 > > So set PF_FSTRANS to avoid this causing a deadlock. Another "You broke KM_NOFS" moment. You win a Kit Kat. ;) xfs_trans_add_item(): lidp = kmem_zone_zalloc(xfs_log_item_desc_zone, KM_SLEEP | KM_NOFS); KM_NOFS needs to work, otherwise XFS is just a huge steaming pile of memory reclaim deadlocks regardless of whether you are using loopback NFS or not. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs