From patchwork Sat Jan 9 07:58:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12007985 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4109C43333 for ; Sat, 9 Jan 2021 08:00:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8915A238E8 for ; Sat, 9 Jan 2021 08:00:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726663AbhAIIA0 (ORCPT ); Sat, 9 Jan 2021 03:00:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:40962 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbhAIIAZ (ORCPT ); Sat, 9 Jan 2021 03:00:25 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5A4D023A5B; Sat, 9 Jan 2021 07:59:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610179184; bh=r+iSj8HBgvEzfJp78mWo1kCacxf8t3pr0DVy9t0EPKU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PzwNpXPgzzhKMQZWWgDwsQPa8KffMcjNGPEaHSRXHIdDVvkTCc1tkTwLsQZgfzg71 84kj5xvzn6qcxO6wc/u0ZFxyNVfATA0XY849ko+2s2WWiIJEWvee7qgb/nyr7z9Rv2 2d2aDeJbgtqdWOVD5MiJ0gFX/ckdkChPtlgMpFQgPc5Cj0UlJaKkKB+eEqNows1uqY SxJIWPAKdn6JVzXk38xPen8V/5iryIKn2Zf9WUqOHa662DbtNnuypkL0i1ofbK6UMz 4WVuyQ6Ddm3zz6l9R7o884+vHAK805R3dESA1NBRaA2noYYkhcP83g5t0aGKeWs17l JA3uG2Bn29ncQ== From: Eric Biggers To: linux-fsdevel@vger.kernel.org Cc: linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, Theodore Ts'o , Christoph Hellwig Subject: [PATCH v2 02/12] fs: correctly document the inode dirty flags Date: Fri, 8 Jan 2021 23:58:53 -0800 Message-Id: <20210109075903.208222-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210109075903.208222-1-ebiggers@kernel.org> References: <20210109075903.208222-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Eric Biggers The documentation for I_DIRTY_SYNC and I_DIRTY_DATASYNC is a bit misleading, and I_DIRTY_TIME isn't documented at all. Fix this. Reviewed-by: Christoph Hellwig Signed-off-by: Eric Biggers Reviewed-by: Jan Kara --- include/linux/fs.h | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index fd47deea7c176..45a0303b2aeb6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2084,8 +2084,8 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, /* * Inode state bits. Protected by inode->i_lock * - * Three bits determine the dirty state of the inode, I_DIRTY_SYNC, - * I_DIRTY_DATASYNC and I_DIRTY_PAGES. + * Four bits determine the dirty state of the inode: I_DIRTY_SYNC, + * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME. * * Four bits define the lifetime of an inode. Initially, inodes are I_NEW, * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at @@ -2094,12 +2094,20 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, * Two bits are used for locking and completion notification, I_NEW and I_SYNC. * * I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on - * fdatasync(). i_atime is the usual cause. - * I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of + * fdatasync() (unless I_DIRTY_DATASYNC is also set). + * Timestamp updates are the usual cause. + * I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of * these changes separately from I_DIRTY_SYNC so that we * don't have to write inode on fdatasync() when only - * mtime has changed in it. + * e.g. the timestamps have changed. * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean. + * I_DIRTY_TIME The inode itself only has dirty timestamps, and the + * lazytime mount option is enabled. We keep track of this + * separately from I_DIRTY_SYNC in order to implement + * lazytime. This gets cleared if I_DIRTY_INODE + * (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. I.e. + * either I_DIRTY_TIME *or* I_DIRTY_INODE can be set in + * i_state, but not both. I_DIRTY_PAGES may still be set. * I_NEW Serves as both a mutex and completion notification. * New inodes set I_NEW. If two processes both create * the same inode, one of them will release its inode and