From patchwork Mon Apr 8 21:32:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 234906 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id F1F9E2C00A9 for ; Tue, 9 Apr 2013 07:33:33 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965131Ab3DHVda (ORCPT ); Mon, 8 Apr 2013 17:33:30 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53399 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936368Ab3DHVdH (ORCPT ); Mon, 8 Apr 2013 17:33:07 -0400 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 76B33A5202; Mon, 8 Apr 2013 23:33:01 +0200 (CEST) Received: by quack.suse.cz (Postfix, from userid 1000) id 8E3DE2069A; Mon, 8 Apr 2013 23:33:00 +0200 (CEST) From: Jan Kara To: Ted Tso Cc: linux-ext4@vger.kernel.org, Jan Kara Subject: [PATCH 24/29] ext4: Remove wait for unwritten extent conversion from ext4_ext_truncate() Date: Mon, 8 Apr 2013 23:32:29 +0200 Message-Id: <1365456754-29373-25-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1365456754-29373-1-git-send-email-jack@suse.cz> References: <1365456754-29373-1-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Since PageWriteback bit is now cleared after extents are converted from unwritten to written ones, we have full exclusion of writeback path from truncate (truncate_inode_pages() waits for PageWriteback bits to get cleared on all invalidated pages). Exclusion from DIO path is achieved by inode_dio_wait() call in ext4_setattr(). So there's no need to wait for extent convertion in ext4_ext_truncate() anymore. Signed-off-by: Jan Kara Reviewed-by: Zheng Liu --- fs/ext4/extents.c | 6 ------ fs/ext4/page-io.c | 9 ++++++++- 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index ae22735..ca4ff71 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4256,12 +4256,6 @@ void ext4_ext_truncate(struct inode *inode) int err = 0; /* - * finish any pending end_io work so we won't run the risk of - * converting any truncated blocks to initialized later - */ - ext4_flush_unwritten_io(inode); - - /* * probably first extent we're gonna free will be last in block */ err = ext4_writepage_trans_blocks(inode); diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 2967794..2f0b943 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -145,7 +145,14 @@ static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) wake_up_all(ext4_ioend_wq(inode)); } -/* check a range of space and convert unwritten extents to written. */ +/* + * Check a range of space and convert unwritten extents to written. Note that + * we are protected from truncate touching same part of extent tree by the + * fact that truncate code waits for all DIO to finish (thus exclusion from + * direct IO is achieved) and also waits for PageWriteback bits. Thus we + * cannot get to ext4_ext_truncate() before all IOs overlapping that range are + * completed (happens from ext4_free_ioend()). + */ static int ext4_end_io(ext4_io_end_t *io) { struct inode *inode = io->inode;