From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id 923BF6B007B for ; Wed, 16 Apr 2014 02:31:32 -0400 (EDT) Received: by mail-pd0-f169.google.com with SMTP id fp1so10446736pdb.28 for ; Tue, 15 Apr 2014 23:31:32 -0700 (PDT) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net. [2001:44b8:8060:ff02:300:1:6:6]) by mx.google.com with ESMTP id xy8si12107444pab.201.2014.04.15.23.31.30 for ; Tue, 15 Apr 2014 23:31:31 -0700 (PDT) Date: Wed, 16 Apr 2014 16:31:29 +1000 From: Dave Chinner Subject: Re: [PATCH 09/19] XFS: ensure xfs_file_*_read cannot deadlock in memory allocation. Message-ID: <20140416063129.GI15995@dastard> References: <20140416033623.10604.69237.stgit@notabene.brown> <20140416040336.10604.90380.stgit@notabene.brown> <20140416060459.GE15995@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140416060459.GE15995@dastard> Sender: owner-linux-mm@kvack.org List-ID: 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 04:04:59PM +1000, Dave Chinner wrote: > On Wed, Apr 16, 2014 at 02:03:36PM +1000, NeilBrown wrote: > > xfs_file_*_read holds an inode lock while calling a generic 'read' > > function. These functions perform read-ahead and are quite likely to > > allocate memory. > > Yes, that's what reading data from disk requires. > > > So set PF_FSTRANS to ensure they avoid __GFP_FS and so don't recurse > > into a filesystem to free memory. > > We already have that protection via the Oops, stray paste. Ignore that comment. -Dave. -- Dave Chinner david@fromorbit.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org