From patchwork Tue Jan 5 00:54:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11997861 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=-19.2 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 5FE61C4332D for ; Tue, 5 Jan 2021 00:56:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4216522581 for ; Tue, 5 Jan 2021 00:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727677AbhAEA4a (ORCPT ); Mon, 4 Jan 2021 19:56:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:38148 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726329AbhAEA42 (ORCPT ); Mon, 4 Jan 2021 19:56:28 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CD664225AA; Tue, 5 Jan 2021 00:55:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609808109; bh=H1ms59/bip1WURh53Z2hT3TghGoA+Y1uZAJZTjqPVbA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jT5YHwMUgMCR7wlwaRdowKZM9R6gvPc5q8QsYcKqluLVv9qzVzb5ZLYpj+8BJinTA 1tYt5wwFZVp0RDAxpBlc63HhVpNF5Rk3zgXbvdiFBSWfIpLrDX8Mmfq1MVoz9YClb1 9Gr2aATxyaLdxZqNOHjdmFblPWbRTyzC/RA158eyh4sD8Aa3guZw/r8EudMGbINKUJ w+1wvYWfRCLiPz4E7Qnid8lt7OG7jDwfbEzObQJGnso821wgCnsJYkDVJxNx555AOD 74UKgJtYKhCO2Xw93w+7ZABhUKMlAxqRerT5DGy3IKUeXa5hwHmJYWfpjPMb/kOHAy 7Gqk1iDUurBeg== From: Eric Biggers To: linux-fsdevel@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, Theodore Ts'o , Christoph Hellwig Subject: [PATCH 07/13] fs: correctly document the inode dirty flags Date: Mon, 4 Jan 2021 16:54:46 -0800 Message-Id: <20210105005452.92521-8-ebiggers@kernel.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210105005452.92521-1-ebiggers@kernel.org> References: <20210105005452.92521-1-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. Signed-off-by: Eric Biggers Reviewed-by: Christoph Hellwig --- 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