From patchwork Wed Jun 29 11:26:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Yi X-Patchwork-Id: 1649985 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4LXzPH2bhwz9sG2 for ; Wed, 29 Jun 2022 21:14:11 +1000 (AEST) Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4LXzPG6svlz4xDH for ; Wed, 29 Jun 2022 21:14:10 +1000 (AEST) Received: by gandalf.ozlabs.org (Postfix) id 4LXzPG6pZrz4xR1; Wed, 29 Jun 2022 21:14:10 +1000 (AEST) Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: gandalf.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4LXzPG6kdQz4xDH for ; Wed, 29 Jun 2022 21:14:10 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231741AbiF2LOK (ORCPT ); Wed, 29 Jun 2022 07:14:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231489AbiF2LOJ (ORCPT ); Wed, 29 Jun 2022 07:14:09 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8DAC3E0F7 for ; Wed, 29 Jun 2022 04:14:08 -0700 (PDT) Received: from canpemm500005.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LXzK811g1zTgCH; Wed, 29 Jun 2022 19:10:36 +0800 (CST) Received: from huawei.com (10.175.127.227) by canpemm500005.china.huawei.com (7.192.104.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 29 Jun 2022 19:14:05 +0800 From: Zhang Yi To: CC: , , , , Subject: [PATCH v3 1/2] ext4: silence the warning when evicting inode with dioread_nolock Date: Wed, 29 Jun 2022 19:26:46 +0800 Message-ID: <20220629112647.4141034-1-yi.zhang@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500005.china.huawei.com (7.192.104.229) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org When evicting an inode with default dioread_nolock, it could be raced by the unwritten extents converting kworker after writeback some new allocated dirty blocks. It convert unwritten extents to written, the extents could be merged to upper level and free extent blocks, so it could mark the inode dirty again even this inode has been marked I_FREEING. But the inode->i_io_list check and warning in ext4_evict_inode() missing this corner case. Fortunately, ext4_evict_inode() will wait all extents converting finished before this check, so it will not lead to inode use-after-free problem, every thing is OK besides this warning. The WARN_ON_ONCE was originally designed for finding inode use-after-free issues in advance, but if we add current dioread_nolock case in, it will become not quite useful, so fix this warning by just remove this check. ====== WARNING: CPU: 7 PID: 1092 at fs/ext4/inode.c:227 ext4_evict_inode+0x875/0xc60 ... RIP: 0010:ext4_evict_inode+0x875/0xc60 ... Call Trace: evict+0x11c/0x2b0 iput+0x236/0x3a0 do_unlinkat+0x1b4/0x490 __x64_sys_unlinkat+0x4c/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fa933c1115b ====== rm kworker ext4_end_io_end() vfs_unlink() ext4_unlink() ext4_convert_unwritten_io_end_vec() ext4_convert_unwritten_extents() ext4_map_blocks() ext4_ext_map_blocks() ext4_ext_try_to_merge_up() __mark_inode_dirty() check !I_FREEING locked_inode_to_wb_and_lock_list() iput() iput_final() evict() ext4_evict_inode() truncate_inode_pages_final() //wait release io_end inode_io_list_move_locked() ext4_release_io_end() trigger WARN_ON_ONCE() Fixes: ceff86fddae8 ("ext4: Avoid freeing inodes on dirty list") Signed-off-by: Zhang Yi Reviewed-by: Jan Kara --- fs/ext4/inode.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 84c0eb55071d..702cc208689a 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -220,13 +220,13 @@ void ext4_evict_inode(struct inode *inode) /* * For inodes with journalled data, transaction commit could have - * dirtied the inode. Flush worker is ignoring it because of I_FREEING - * flag but we still need to remove the inode from the writeback lists. + * dirtied the inode. And for inodes with dioread_nolock, unwritten + * extents converting worker could merge extents and also have dirtied + * the inode. Flush worker is ignoring it because of I_FREEING flag but + * we still need to remove the inode from the writeback lists. */ - if (!list_empty_careful(&inode->i_io_list)) { - WARN_ON_ONCE(!ext4_should_journal_data(inode)); + if (!list_empty_careful(&inode->i_io_list)) inode_io_list_del(inode); - } /* * Protect us against freezing - iput() caller didn't have to have any