Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932517AbaBEUrx (ORCPT ); Wed, 5 Feb 2014 15:47:53 -0500 Received: from mail1.windriver.com ([147.11.146.13]:48279 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932153AbaBEUGR (ORCPT ); Wed, 5 Feb 2014 15:06:17 -0500 From: Paul Gortmaker To: , CC: Hugh Dickins , Rik van Riel , Johannes Weiner , Michel Lespinasse , Ying Han , Andrew Morton , Linus Torvalds , Paul Gortmaker Subject: [v2.6.34-stable 103/213] mm: fix invalidate_complete_page2() lock ordering Date: Wed, 5 Feb 2014 15:00:58 -0500 Message-ID: <1391630568-49251-104-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> References: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hugh Dickins ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit ec4d9f626d5908b6052c2973f37992f1db52e967 upstream. In fuzzing with trinity, lockdep protested "possible irq lock inversion dependency detected" when isolate_lru_page() reenabled interrupts while still holding the supposedly irq-safe tree_lock: invalidate_inode_pages2 invalidate_complete_page2 spin_lock_irq(&mapping->tree_lock) clear_page_mlock isolate_lru_page spin_unlock_irq(&zone->lru_lock) isolate_lru_page() is correct to enable interrupts unconditionally: invalidate_complete_page2() is incorrect to call clear_page_mlock() while holding tree_lock, which is supposed to nest inside lru_lock. Both truncate_complete_page() and invalidate_complete_page() call clear_page_mlock() before taking tree_lock to remove page from radix_tree. I guess invalidate_complete_page2() preferred to test PageDirty (again) under tree_lock before committing to the munlock; but since the page has already been unmapped, its state is already somewhat inconsistent, and no worse if clear_page_mlock() moved up. Reported-by: Sasha Levin Deciphered-by: Andrew Morton Signed-off-by: Hugh Dickins Acked-by: Mel Gorman Cc: Rik van Riel Cc: Johannes Weiner Cc: Michel Lespinasse Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Paul Gortmaker --- mm/truncate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/truncate.c b/mm/truncate.c index f42675a3615d..d0698a15c61f 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -381,11 +381,12 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page) if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return 0; + clear_page_mlock(page); + spin_lock_irq(&mapping->tree_lock); if (PageDirty(page)) goto failed; - clear_page_mlock(page); BUG_ON(page_has_private(page)); __remove_from_page_cache(page); spin_unlock_irq(&mapping->tree_lock); -- 1.8.5.2 -- 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/