From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ea0-f180.google.com (mail-ea0-f180.google.com [209.85.215.180]) by kanga.kvack.org (Postfix) with ESMTP id B6FF76B0031 for ; Fri, 7 Feb 2014 10:20:48 -0500 (EST) Received: by mail-ea0-f180.google.com with SMTP id o10so1640216eaj.39 for ; Fri, 07 Feb 2014 07:20:48 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id k3si8922058eep.15.2014.02.07.07.20.39 for ; Fri, 07 Feb 2014 07:20:43 -0800 (PST) From: Rafael Aquini Subject: [PATCH] mm: fix page leak at nfs_symlink() Date: Fri, 7 Feb 2014 13:19:54 -0200 Message-Id: Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: trond.myklebust@primarydata.com, jstancek@redhat.com, jlayton@redhat.com, mgorman@suse.de, riel@redhat.com, linux-nfs@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org Changes committed by "a0b8cab3 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 --- fs/nfs/dir.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index be38b57..4a48fe4 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1846,6 +1846,11 @@ int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) 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); -- 1.8.5.3 -- 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