From patchwork Fri Jun 29 13:33:24 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 168081 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D569FB6FA4 for ; Fri, 29 Jun 2012 23:34:19 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932438Ab2F2Nds (ORCPT ); Fri, 29 Jun 2012 09:33:48 -0400 Received: from cantor2.suse.de ([195.135.220.15]:45775 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932186Ab2F2Ndm (ORCPT ); Fri, 29 Jun 2012 09:33:42 -0400 Received: from relay2.suse.de (unknown [195.135.220.254]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id AAAA5A5464; Fri, 29 Jun 2012 15:33:41 +0200 (CEST) From: Mel Gorman To: Andrew Morton Cc: Linux-MM , Linux-Netdev , Linux-NFS , LKML , David Miller , Trond Myklebust , Neil Brown , Christoph Hellwig , Peter Zijlstra , Mike Christie , Eric B Munson , Sebastian Andrzej Siewior , Mel Gorman Subject: [PATCH 11/12] nfs: Prevent page allocator recursions with swap over NFS. Date: Fri, 29 Jun 2012 14:33:24 +0100 Message-Id: <1340976805-5799-12-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.7.9.2 In-Reply-To: <1340976805-5799-1-git-send-email-mgorman@suse.de> References: <1340976805-5799-1-git-send-email-mgorman@suse.de> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate IO, just not of any filesystem data. The problem is that previously NOFS was correct because that avoids recursion into the NFS code. With swap-over-NFS, it is no longer correct as swap IO can lead to this recursion. Signed-off-by: Peter Zijlstra Signed-off-by: Mel Gorman Acked-by: Rik van Riel --- fs/nfs/pagelist.c | 2 +- fs/nfs/write.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 9ef8b3c..7de1646 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -70,7 +70,7 @@ void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos) static inline struct nfs_page * nfs_page_alloc(void) { - struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL); + struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO); if (p) INIT_LIST_HEAD(&p->wb_list); return p; diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 947e1e6..0f7fdb7 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -52,7 +52,7 @@ static mempool_t *nfs_commit_mempool; struct nfs_commit_data *nfs_commitdata_alloc(void) { - struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS); + struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO); if (p) { memset(p, 0, sizeof(*p)); @@ -70,7 +70,7 @@ EXPORT_SYMBOL_GPL(nfs_commit_free); struct nfs_write_header *nfs_writehdr_alloc(void) { - struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS); + struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO); if (p) { struct nfs_pgio_header *hdr = &p->header;