From patchwork Tue Aug 30 08:10:12 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongqiang Yang X-Patchwork-Id: 112194 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 868BAB6F9C for ; Tue, 30 Aug 2011 18:53:49 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751074Ab1H3Ixs (ORCPT ); Tue, 30 Aug 2011 04:53:48 -0400 Received: from mail-vw0-f46.google.com ([209.85.212.46]:57578 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750949Ab1H3Ixs (ORCPT ); Tue, 30 Aug 2011 04:53:48 -0400 Received: by vws1 with SMTP id 1so5211024vws.19 for ; Tue, 30 Aug 2011 01:53:47 -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=DGOZ01hBVSZFhqjybQDPg7ZWtmTkquExtk2Vq/6mHWw=; b=iUaVY6bHDDSnPki16n0D9TmjqYFecAE4XNHIVgCdoGCO18Vh7RGZI7Aw53furWMx+R IKzmOs8jowkX5mmM3VWf/H3gIfGdccsKmDcxc+9jDEbFQkDzG3SPuauzM3qTu6tcIswq BqCZpQzusiwwnFM4pVcNaYE/3kyXMfRwjy3JA= Received: by 10.142.136.5 with SMTP id j5mr2937766wfd.18.1314694426818; Tue, 30 Aug 2011 01:53:46 -0700 (PDT) Received: from localhost.localdomain ([159.226.43.42]) by mx.google.com with ESMTPS id t6sm8483074pbg.4.2011.08.30.01.53.44 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 30 Aug 2011 01:53:46 -0700 (PDT) From: Yongqiang Yang To: tytso@mit.edu Cc: adilger@dilger.ca, linux-ext4@vger.kernel.org, Yongqiang Yang Subject: [PATCH v2 02/15] ext4: add a function which adds a new desc to a fs Date: Tue, 30 Aug 2011 16:10:12 +0800 Message-Id: <1314691825-12295-3-git-send-email-xiaoqiangnk@gmail.com> X-Mailer: git-send-email 1.7.5.1 In-Reply-To: <1314691825-12295-1-git-send-email-xiaoqiangnk@gmail.com> References: <1314691825-12295-1-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_add_new_desc() which adds a new desc to a fs 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 | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 42 insertions(+), 0 deletions(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 5126aac..b577647 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -735,6 +735,48 @@ exit_err: } } +/* + * ext4_add_new_desc() adds group descriptor of group @group + * + * @handle: journal handle + * @sb; super block + * @group: the group no. of the first group desc to be added + * @resize_inode: the resize inode + */ +static int ext4_add_new_desc(handle_t *handle, struct super_block *sb, + ext4_group_t group, struct inode *resize_inode) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + struct buffer_head *gdb_bh; + int gdb_off, gdb_num, err = 0; + int reserved_gdb = ext4_bg_has_super(sb, group) ? + le16_to_cpu(es->s_reserved_gdt_blocks) : 0; + + gdb_off = group % EXT4_DESC_PER_BLOCK(sb); + gdb_num = group / EXT4_DESC_PER_BLOCK(sb); + + /* + * We will only either add reserved group blocks to a backup group + * or remove reserved blocks for the first group in a new group block. + * Doing both would be mean more complex code, and sane people don't + * use non-sparse filesystems anymore. This is already checked above. + */ + if (gdb_off) { + gdb_bh = sbi->s_group_desc[gdb_num]; + err = ext4_journal_get_write_access(handle, gdb_bh); + if (err) + goto out; + + if (reserved_gdb && ext4_bg_num_gdb(sb, group)) + err = reserve_backup_gdb(handle, resize_inode, group); + } else + err = add_new_gdb(handle, resize_inode, group); + +out: + return err; +} + /* 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