From patchwork Fri Mar 20 02:52:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Theodore Ts'o X-Patchwork-Id: 1258606 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=mit.edu Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48k7ct0FG1z9sSQ for ; Fri, 20 Mar 2020 13:53:18 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726666AbgCTCxR (ORCPT ); Thu, 19 Mar 2020 22:53:17 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:50033 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725856AbgCTCxR (ORCPT ); Thu, 19 Mar 2020 22:53:17 -0400 Received: from callcc.thunk.org (pool-72-93-95-157.bstnma.fios.verizon.net [72.93.95.157]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 02K2r1pT016072 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 19 Mar 2020 22:53:01 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id 068E4420EBA; Thu, 19 Mar 2020 22:53:00 -0400 (EDT) From: "Theodore Ts'o" To: Ext4 Developers List , linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org Cc: "Theodore Ts'o" , Eric Biggers Subject: [PATCH 1/2] writeback: avoid double-writing the inode on a lazytime expiration Date: Thu, 19 Mar 2020 22:52:54 -0400 Message-Id: <20200320025255.1705972-1-tytso@mit.edu> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200320024639.GH1067245@mit.edu> References: <20200320024639.GH1067245@mit.edu> MIME-Version: 1.0 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org In the case that an inode has dirty timestamp for longer than the lazytime expiration timeout (or if all such inodes are being flushed out due to a sync or syncfs system call), we need to inform the file system that the inode is dirty so that the inode's timestamps can be copied out to the on-disk data structures. That's because if the file system supports lazytime, it will have ignored the dirty_inode(inode, I_DIRTY_TIME) notification when the timestamp was modified in memory.q Previously, this was accomplished by calling mark_inode_dirty_sync(), but that has the unfortunate side effect of also putting the inode the writeback list, and that's not necessary in this case, since we will immediately call write_inode() afterwards. Eric Biggers noticed that this was causing problems for fscrypt after the key was removed[1]. [1] https://lore.kernel.org/r/20200306004555.GB225345@gmail.com Reported-by: Eric Biggers Signed-off-by: Theodore Ts'o --- fs/fs-writeback.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 76ac9c7d32ec..867454997c9d 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1504,8 +1504,9 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) spin_unlock(&inode->i_lock); - if (dirty & I_DIRTY_TIME) - mark_inode_dirty_sync(inode); + /* This was a lazytime expiration; we need to tell the file system */ + if (dirty & I_DIRTY_TIME_EXPIRED && inode->i_sb->s_op->dirty_inode) + inode->i_sb->s_op->dirty_inode(inode, I_DIRTY_SYNC); /* Don't write the inode if only I_DIRTY_PAGES was set */ if (dirty & ~I_DIRTY_PAGES) { int err = write_inode(inode, wbc);