From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965098Ab0HFT1z (ORCPT ); Fri, 6 Aug 2010 15:27:55 -0400 Received: from kroah.org ([198.145.64.141]:43459 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935041Ab0HFT1r (ORCPT ); Fri, 6 Aug 2010 15:27:47 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Aug 6 12:21:14 2010 Message-Id: <20100806192114.625731503@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 06 Aug 2010 12:19:43 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Trond Myklebust Subject: [02/36] NFS: kswapd must not block in nfs_release_page In-Reply-To: <20100806192649.GA1614@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.34-stable review patch. If anyone has any objections, please let us know. ------------------ From: Trond Myklebust commit b608b283a962caaa280756bc8563016a71712acf upstream. See https://bugzilla.kernel.org/show_bug.cgi?id=16056 If other processes are blocked waiting for kswapd to free up some memory so that they can make progress, then we cannot allow kswapd to block on those processes. Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/file.c | 13 +++++++++++-- fs/nfs/write.c | 4 ++-- include/linux/nfs_fs.h | 1 + 3 files changed, 14 insertions(+), 4 deletions(-) --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -489,11 +490,19 @@ static void nfs_invalidate_page(struct p */ static int nfs_release_page(struct page *page, gfp_t gfp) { + struct address_space *mapping = page->mapping; + dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); /* Only do I/O if gfp is a superset of GFP_KERNEL */ - if ((gfp & GFP_KERNEL) == GFP_KERNEL) - nfs_wb_page(page->mapping->host, page); + if (mapping && (gfp & GFP_KERNEL) == GFP_KERNEL) { + int how = FLUSH_SYNC; + + /* Don't let kswapd deadlock waiting for OOM RPC calls */ + if (current_is_kswapd()) + how = 0; + nfs_commit_inode(mapping->host, how); + } /* If PagePrivate() is set, then the page is not freeable */ if (PagePrivate(page)) return 0; --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1379,7 +1379,7 @@ static const struct rpc_call_ops nfs_com .rpc_release = nfs_commit_release, }; -static int nfs_commit_inode(struct inode *inode, int how) +int nfs_commit_inode(struct inode *inode, int how) { LIST_HEAD(head); int may_wait = how & FLUSH_SYNC; @@ -1443,7 +1443,7 @@ out_mark_dirty: return ret; } #else -static int nfs_commit_inode(struct inode *inode, int how) +int nfs_commit_inode(struct inode *inode, int how) { return 0; } --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -479,6 +479,7 @@ extern int nfs_wb_all(struct inode *inod extern int nfs_wb_page(struct inode *inode, struct page* page); extern int nfs_wb_page_cancel(struct inode *inode, struct page* page); #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) +extern int nfs_commit_inode(struct inode *, int); extern struct nfs_write_data *nfs_commitdata_alloc(void); extern void nfs_commit_free(struct nfs_write_data *wdata); #endif