From patchwork Thu Aug 11 03:28:19 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongqiang Yang X-Patchwork-Id: 109505 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 7043FB6F67 for ; Thu, 11 Aug 2011 13:35:37 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754566Ab1HKDfg (ORCPT ); Wed, 10 Aug 2011 23:35:36 -0400 Received: from mail-pz0-f42.google.com ([209.85.210.42]:48649 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753987Ab1HKDfe (ORCPT ); Wed, 10 Aug 2011 23:35:34 -0400 Received: by mail-pz0-f42.google.com with SMTP id 37so2947235pzk.1 for ; Wed, 10 Aug 2011 20:35:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=/8WSrcmn5DnZy5ot8sh42T9i5fDibZSWoO6ZQB5JbuM=; b=pRlIJyWKre18UcwUjm0fCWZtdpzdPuR00Hgsb3NUjalUfo7TifPlSua+r7qKov5YOZ lnM9vQXevpH3inUsCOjAUyVE/nceJq1z9x55h8dym+/XcY5U3bnjyldw67Ea8dUte8yE jES1XUfjPo6UXI00DHEPSDzQrIYMh4sTAYXDc= Received: by 10.142.211.15 with SMTP id j15mr8022643wfg.219.1313033734485; Wed, 10 Aug 2011 20:35:34 -0700 (PDT) Received: from localhost.localdomain ([159.226.43.42]) by mx.google.com with ESMTPS id g4sm1390823pbj.25.2011.08.10.20.35.32 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 10 Aug 2011 20:35:34 -0700 (PDT) From: Yongqiang Yang To: linux-ext4@vger.kernel.org Cc: aedilger@gmail.com, tytso@mit.edu, Yongqiang Yang Subject: [PATCH 04/13] ext4: add a function which updates super block Date: Thu, 11 Aug 2011 11:28:19 +0800 Message-Id: <1313033308-882-5-git-send-email-xiaoqiangnk@gmail.com> X-Mailer: git-send-email 1.7.5.1 In-Reply-To: <1313033308-882-1-git-send-email-xiaoqiangnk@gmail.com> References: <1313033308-882-1-git-send-email-xiaoqiangnk@gmail.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org This patch adds a function named ext4_update_super() which updates super block and whose code is copied from ext4_group_add(). The function will be used by new resize implementation. Signed-off-by: Yongqiang Yang --- fs/ext4/resize.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 72 insertions(+), 0 deletions(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 6320baa..14be865 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -831,6 +831,78 @@ static int ext4_setup_new_desc(handle_t *handle, struct super_block *sb, return err; } +/* + * ext4_update_super() updates super so that new the added group can be seen + * by the filesystem. + * + * @sb: super block + */ +static void ext4_update_super(struct super_block *sb, + struct ext4_new_group_data *input) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + + /* + * Make the new blocks and inodes valid next. We do this before + * increasing the group count so that once the group is enabled, + * all of its blocks and inodes are already valid. + * + * We always allocate group-by-group, then block-by-block or + * inode-by-inode within a group, so enabling these + * blocks/inodes before the group is live won't actually let us + * allocate the new space yet. + */ + ext4_blocks_count_set(es, ext4_blocks_count(es) + + input->blocks_count); + le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb)); + + /* + * We need to protect s_groups_count against other CPUs seeing + * inconsistent state in the superblock. + * + * The precise rules we use are: + * + * * Writers must perform a smp_wmb() after updating all dependent + * data and before modifying the groups count + * + * * Readers must perform an smp_rmb() after reading the groups count + * and before reading any dependent data. + * + * NB. These rules can be relaxed when checking the group count + * while freeing data, as we can only allocate from a block + * group after serialising against the group count, and we can + * only then free after serialising in turn against that + * allocation. + */ + smp_wmb(); + + /* Update the global fs size fields */ + sbi->s_groups_count++; + + /* Update the reserved block counts only once the new group is + * active. */ + ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + + input->reserved_blocks); + + /* Update the free space counts */ + percpu_counter_add(&sbi->s_freeblocks_counter, + input->free_blocks_count); + percpu_counter_add(&sbi->s_freeinodes_counter, + EXT4_INODES_PER_GROUP(sb)); + + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) && + sbi->s_log_groups_per_flex) { + ext4_group_t flex_group; + flex_group = ext4_flex_group(sbi, input->group); + atomic_add(input->free_blocks_count, + &sbi->s_flex_groups[flex_group].free_blocks); + atomic_add(EXT4_INODES_PER_GROUP(sb), + &sbi->s_flex_groups[flex_group].free_inodes); + } + +} + /* Add group descriptor data to an existing or new group descriptor block. * Ensure we handle all possible error conditions _before_ we start modifying * the filesystem, because we cannot abort the transaction and not have it