From patchwork Tue Jan 5 00:54:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11997865 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 03FABC4361A for ; Tue, 5 Jan 2021 00:56:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCBC52256F for ; Tue, 5 Jan 2021 00:56:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727773AbhAEA4j (ORCPT ); Mon, 4 Jan 2021 19:56:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:38154 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726397AbhAEA42 (ORCPT ); Mon, 4 Jan 2021 19:56:28 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C5ED0225AC; Tue, 5 Jan 2021 00:55:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609808110; bh=3+FH0Che1vvUp1b6v2ElJrJMrgmUrdCi08gAUpQUvaM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vKszdOoUHBXD4lFIk+ly6Zo/bQh1PREYUNt4Btl8oOXy4yCtVIQkPdYgJp5YWRZ8O 7ZVZrhZMUUDLrWnM36P2v8D5hJgH4CCNQdqBrybbQs5udOZJTMAaLWnVmjAylr0cXD Mtvagss0HxuRq9jevJnR6blxmewNJWpnzwYsnqWMdio9/TdmAFNpWoQ6E5ZPbWQJLu NEQ9lR8x5T1AuSXIIzc5SpY9ZbEICahdk95u0GuUrpO7hhx5e9bNxuSCEEu7ggVqfj dDnommsWbX4jY4koZ1KfmXM3BtX/IVnlxdoiM7iNExZyRU/xz4LtTsPaRmecwwm8yX AizzRzc68km7Q== 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 10/13] fs: clean up __mark_inode_dirty() a bit Date: Mon, 4 Jan 2021 16:54:49 -0800 Message-Id: <20210105005452.92521-11-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 Improve some comments, and don't bother checking for the I_DIRTY_TIME flag in the case where we just cleared it. Also, warn if I_DIRTY_TIME and I_DIRTY_PAGES are passed to __mark_inode_dirty() at the same time, as this case isn't handled. Signed-off-by: Eric Biggers Reviewed-by: Christoph Hellwig --- fs/fs-writeback.c | 49 +++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 19 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 3f5a589399afe..ed76112bd067b 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -2227,23 +2227,24 @@ static noinline void block_dump___mark_inode_dirty(struct inode *inode) } /** - * __mark_inode_dirty - internal function + * __mark_inode_dirty - internal function to mark an inode dirty * * @inode: inode to mark - * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) + * @flags: what kind of dirty, e.g. I_DIRTY_SYNC. This can be a combination of + * multiple I_DIRTY_* flags, except that I_DIRTY_TIME can't be combined + * with I_DIRTY_PAGES. * - * Mark an inode as dirty. Callers should use mark_inode_dirty or - * mark_inode_dirty_sync. + * Mark an inode as dirty. We notify the filesystem, then update the inode's + * dirty flags. Then, if needed we add the inode to the appropriate dirty list. * - * Put the inode on the super block's dirty list. + * Most callers should use mark_inode_dirty() or mark_inode_dirty_sync() + * instead of calling this directly. * - * CAREFUL! We mark it dirty unconditionally, but move it onto the - * dirty list only if it is hashed or if it refers to a blockdev. - * If it was not hashed, it will never be added to the dirty list - * even if it is later hashed, as it will have been marked dirty already. + * CAREFUL! We only add the inode to the dirty list if it is hashed or if it + * refers to a blockdev. Unhashed inodes will never be added to the dirty list + * even if they are later hashed, as they will have been marked dirty already. * - * In short, make sure you hash any inodes _before_ you start marking - * them dirty. + * In short, ensure you hash any inodes _before_ you start marking them dirty. * * Note that for blockdevs, inode->dirtied_when represents the dirtying time of * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of @@ -2255,25 +2256,34 @@ static noinline void block_dump___mark_inode_dirty(struct inode *inode) void __mark_inode_dirty(struct inode *inode, int flags) { struct super_block *sb = inode->i_sb; - int dirtytime; + int dirtytime = 0; trace_writeback_mark_inode_dirty(inode, flags); - /* - * Don't do this for I_DIRTY_PAGES - that doesn't actually - * dirty the inode itself - */ if (flags & I_DIRTY_INODE) { + /* + * Notify the filesystem about the inode being dirtied, so that + * (if needed) it can update on-disk fields and journal the + * inode. This is only needed when the inode itself is being + * dirtied now. I.e. it's only needed for I_DIRTY_INODE, not + * for just I_DIRTY_PAGES or I_DIRTY_TIME. + */ trace_writeback_dirty_inode_start(inode, flags); - if (sb->s_op->dirty_inode) sb->s_op->dirty_inode(inode, flags & I_DIRTY_INODE); - trace_writeback_dirty_inode(inode, flags); + /* I_DIRTY_INODE supersedes I_DIRTY_TIME. */ flags &= ~I_DIRTY_TIME; + } else { + /* + * Else it's either I_DIRTY_PAGES, I_DIRTY_TIME, or nothing. + * (We don't support setting both I_DIRTY_PAGES and I_DIRTY_TIME + * in one call to __mark_inode_dirty().) + */ + dirtytime = flags & I_DIRTY_TIME; + WARN_ON_ONCE(dirtytime && (flags != I_DIRTY_TIME)); } - dirtytime = flags & I_DIRTY_TIME; /* * Paired with smp_mb() in __writeback_single_inode() for the @@ -2296,6 +2306,7 @@ void __mark_inode_dirty(struct inode *inode, int flags) inode_attach_wb(inode, NULL); + /* I_DIRTY_INODE supersedes I_DIRTY_TIME. */ if (flags & I_DIRTY_INODE) inode->i_state &= ~I_DIRTY_TIME; inode->i_state |= flags;