From patchwork Tue Nov 8 11:08:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9417165 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9BA5C60585 for ; Tue, 8 Nov 2016 11:10:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8DEAF29027 for ; Tue, 8 Nov 2016 11:10:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8151F2902E; Tue, 8 Nov 2016 11:10:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 156D029027 for ; Tue, 8 Nov 2016 11:10:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933181AbcKHLKy (ORCPT ); Tue, 8 Nov 2016 06:10:54 -0500 Received: from mx2.suse.de ([195.135.220.15]:34643 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933006AbcKHLKk (ORCPT ); Tue, 8 Nov 2016 06:10:40 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 773EAAD4F; Tue, 8 Nov 2016 11:08:33 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id D67201E0F9F; Tue, 8 Nov 2016 12:08:24 +0100 (CET) From: Jan Kara To: Ted Tso Cc: , , Christoph Hellwig , Ross Zwisler , Jan Kara Subject: [PATCH 06/11] ext4: Avoid split extents for DAX writes Date: Tue, 8 Nov 2016 12:08:12 +0100 Message-Id: <1478603297-11793-7-git-send-email-jack@suse.cz> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1478603297-11793-1-git-send-email-jack@suse.cz> References: <1478603297-11793-1-git-send-email-jack@suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently mapping of blocks for DAX writes happen with EXT4_GET_BLOCKS_PRE_IO flag set. That has a result that each ext4_map_blocks() call creates a separate written extent, although it could be merged to the neighboring extents in the extent tree. The reason for using this flag is that in case the extent is unwritten, we need to convert it to written one and zero it out. However this "convert mapped range to written" operation is already implemented by ext4_map_blocks() for the case of data writes into unwritten extent. So just use flags for that mode of operation, simplify the code, and avoid unnecessary split extents. Signed-off-by: Jan Kara --- fs/ext4/inode.c | 17 ----------------- 1 file changed, 17 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index a7079cab645a..3192ec0768d4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3351,7 +3351,6 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, return PTR_ERR(handle); ret = ext4_map_blocks(handle, inode, &map, - EXT4_GET_BLOCKS_PRE_IO | EXT4_GET_BLOCKS_CREATE_ZERO); if (ret < 0) { ext4_journal_stop(handle); @@ -3360,22 +3359,6 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, goto retry; return ret; } - /* For DAX writes we need to zero out unwritten extents */ - if (map.m_flags & EXT4_MAP_UNWRITTEN) { - /* - * We are protected by i_mmap_sem or i_rwsem so we know - * block cannot go away from under us even though we - * dropped i_data_sem. Convert extent to written and - * write zeros there. - */ - ret = ext4_map_blocks(handle, inode, &map, - EXT4_GET_BLOCKS_CONVERT | - EXT4_GET_BLOCKS_CREATE_ZERO); - if (ret < 0) { - ext4_journal_stop(handle); - return ret; - } - } /* * If we added blocks beyond i_size we need to make sure they