From patchwork Sun Oct 25 03:41:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengguang Xu X-Patchwork-Id: 11855159 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 23963697 for ; Sun, 25 Oct 2020 03:42:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC62121734 for ; Sun, 25 Oct 2020 03:42:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mykernel.net header.i=cgxu519@mykernel.net header.b="JiUSoqqn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1766976AbgJYDmc (ORCPT ); Sat, 24 Oct 2020 23:42:32 -0400 Received: from sender2-op-o12.zoho.com.cn ([163.53.93.243]:17126 "EHLO sender2-op-o12.zoho.com.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1766959AbgJYDm3 (ORCPT ); Sat, 24 Oct 2020 23:42:29 -0400 ARC-Seal: i=1; a=rsa-sha256; t=1603597311; cv=none; d=zoho.com.cn; s=zohoarc; b=mf0E1TTJ/NgWDOtk+K3qkCCQG3eO8UaPWfKxjnXjNNNe37iaZItpr8aNLL1zWQNV+2ywZJZM7lTqII+DLRvwdXHQ1jfrt6BuNqGuQggHKe6oBXeFEj4gXtOZiSO0Xlkpchrq3sxOLRCdWo+obYYip5swIcAAofIkDhmtZxdwvdE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com.cn; s=zohoarc; t=1603597311; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:To; bh=v2u7N4GC7c2BP/wK2MnBMpBehRe3CxkK27J7gPJ6l0k=; b=KfREJwtBknnJVJpamBgPuUt4QQCrRge3LYqKMgU5fAVtYUAQwgbNrlTx9BN57Hf+E6kJKCfCO0D8NEuB74gP8vRpKeqeuicwN0snDG6+9pbYoXx/VNRssORkE0ip+Wbg/Q/AFj0UfuwhLZH/sytatJ667zR6xWVfRhoZ4lggYgY= ARC-Authentication-Results: i=1; mx.zoho.com.cn; dkim=pass header.i=mykernel.net; spf=pass smtp.mailfrom=cgxu519@mykernel.net; dmarc=pass header.from= header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1603597311; s=zohomail; d=mykernel.net; i=cgxu519@mykernel.net; h=From:To:Cc:Message-ID:Subject:Date:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Content-Type; bh=v2u7N4GC7c2BP/wK2MnBMpBehRe3CxkK27J7gPJ6l0k=; b=JiUSoqqnMcqHnuIjdM7JIxaeUFs7z1eZfbO2J/UrL16GZMAsoTbcY4NyCi1ec5Az bIzga9P8iPQY/0syhj67RuTAQLPMavpO1jyjj33X06WXSBt5LZTMEFqP+k+8LbfAyJz B1M+77BeT44i7HeBNtbcrLAqOVM76h2Dk5uLin+o= Received: from localhost.localdomain (113.88.132.7 [113.88.132.7]) by mx.zoho.com.cn with SMTPS id 160359731016595.65073159649478; Sun, 25 Oct 2020 11:41:50 +0800 (CST) From: Chengguang Xu To: miklos@szeredi.hu, amir73il@gmail.com, jack@suse.cz Cc: linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Chengguang Xu Message-ID: <20201025034117.4918-3-cgxu519@mykernel.net> Subject: [RFC PATCH v2 2/8] ovl: implement ->writepages operation Date: Sun, 25 Oct 2020 11:41:11 +0800 X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201025034117.4918-1-cgxu519@mykernel.net> References: <20201025034117.4918-1-cgxu519@mykernel.net> MIME-Version: 1.0 X-ZohoCNMailClient: External Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Implement overlayfs' ->writepages operation so that we can sync dirty data/metadata to upper filesystem. Signed-off-by: Chengguang Xu --- fs/overlayfs/inode.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index b584dca845ba..f27fc5be34df 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "overlayfs.h" @@ -516,7 +517,32 @@ static const struct inode_operations ovl_special_inode_operations = { .update_time = ovl_update_time, }; +static int ovl_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct inode *upper_inode = ovl_inode_upper(mapping->host); + struct ovl_fs *ofs = mapping->host->i_sb->s_fs_info; + struct writeback_control tmp_wbc = *wbc; + + if (!ovl_should_sync(ofs)) + return 0; + + /* + * for sync(2) writeback, it has a separate external IO + * completion path by checking PAGECACHE_TAG_WRITEBACK + * in pagecache, we have to set for_sync to 0 in thie case, + * let writeback waits completion after syncing individual + * dirty inode, because we haven't implemented overlayfs' + * own pagecache yet. + */ + if (wbc->for_sync && (wbc->sync_mode == WB_SYNC_ALL)) + tmp_wbc.for_sync = 0; + + return sync_inode(upper_inode, &tmp_wbc); +} + static const struct address_space_operations ovl_aops = { + .writepages = ovl_writepages, /* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */ .direct_IO = noop_direct_IO, };