Return-Path: linux-nfs-owner@vger.kernel.org Received: from cantor2.suse.de ([195.135.220.15]:33648 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762154Ab2EQOvl (ORCPT ); Thu, 17 May 2012 10:51:41 -0400 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 , Mel Gorman Subject: [PATCH 11/12] nfs: Prevent page allocator recursions with swap over NFS. Date: Thu, 17 May 2012 15:51:24 +0100 Message-Id: <1337266285-8102-12-git-send-email-mgorman@suse.de> In-Reply-To: <1337266285-8102-1-git-send-email-mgorman@suse.de> References: <1337266285-8102-1-git-send-email-mgorman@suse.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 --- fs/nfs/pagelist.c | 2 +- fs/nfs/write.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 77aa83e..8e80d71 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -29,7 +29,7 @@ static struct kmem_cache *nfs_page_cachep; 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 21cfe71..abdbe61 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -52,7 +52,7 @@ static mempool_t *nfs_commit_mempool; struct nfs_write_data *nfs_commitdata_alloc(void) { - struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS); + struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO); if (p) { memset(p, 0, sizeof(*p)); @@ -72,7 +72,7 @@ EXPORT_SYMBOL_GPL(nfs_commit_free); struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount) { - struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS); + struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO); if (p) { memset(p, 0, sizeof(*p)); @@ -81,7 +81,8 @@ struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount) if (pagecount <= ARRAY_SIZE(p->page_array)) p->pagevec = p->page_array; else { - p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS); + p->pagevec = kcalloc(pagecount, sizeof(struct page *), + GFP_NOIO); if (!p->pagevec) { mempool_free(p, nfs_wdata_mempool); p = NULL; -- 1.7.9.2