From a0b54adda3fe4b4cc6d28f2a9217cd35d1aa888c Mon Sep 17 00:00:00 2001 From: Rafael Aquini Date: Mon, 10 Feb 2014 14:25:48 -0800 Subject: [PATCH] mm: fix page leak at nfs_symlink() 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 Cc: [3.11.x+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfs/dir.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index be38b573495a..4a48fe4b84b6 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); -- 2.30.2