Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755529AbaBTXwJ (ORCPT ); Thu, 20 Feb 2014 18:52:09 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45702 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755504AbaBTXwF (ORCPT ); Thu, 20 Feb 2014 18:52:05 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Stancek , Rafael Aquini , Mel Gorman , Rik van Riel , Jeff Layton , Trond Myklebust , Andrew Morton , Linus Torvalds Subject: [PATCH 3.12 04/82] mm: fix page leak at nfs_symlink() Date: Thu, 20 Feb 2014 15:51:47 -0800 Message-Id: <20140220235019.617973834@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140220235019.483734207@linuxfoundation.org> References: <20140220235019.483734207@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rafael Aquini commit a0b54adda3fe4b4cc6d28f2a9217cd35d1aa888c upstream. Changes in commit a0b8cab3b9b2 ("mm: remove lru parameter from __pagevec_lru_add and remove parts of pagevec API") have introduced a call to add_to_page_cache_lru() which causes a leak in nfs_symlink() as now the page gets an extra refcount that is not dropped. Jan Stancek observed and reported the leak effect while running test8 from Connectathon Testsuite. After several iterations over the test case, which creates several symlinks on a NFS mountpoint, the test system was quickly getting into an out-of-memory scenario. This patch fixes the page leak by dropping that extra refcount add_to_page_cache_lru() is grabbing. Signed-off-by: Jan Stancek Signed-off-by: Rafael Aquini Acked-by: Mel Gorman Acked-by: Rik van Riel Cc: Jeff Layton Cc: Trond Myklebust Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/nfs/dir.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1852,6 +1852,11 @@ int nfs_symlink(struct inode *dir, struc GFP_KERNEL)) { SetPageUptodate(page); unlock_page(page); + /* + * add_to_page_cache_lru() grabs an extra page refcount. + * Drop it here to avoid leaking this page later. + */ + page_cache_release(page); } else __free_page(page); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/