From: Yongqiang Yang Subject: [PATCH v4 03/15] ext4: add a function which sets up a new group desc Date: Sat, 19 Nov 2011 17:57:09 +0800 Message-ID: <1321696641-14437-4-git-send-email-xiaoqiangnk@gmail.com> References: <1321696641-14437-1-git-send-email-xiaoqiangnk@gmail.com> Cc: adilger@dilger.ca, linux-ext4@vger.kernel.org, Yongqiang Yang To: tytso@mit.edu Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:37586 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799Ab1KSMbJ (ORCPT ); Sat, 19 Nov 2011 07:31:09 -0500 Received: by ghbz2 with SMTP id z2so1450020ghb.19 for ; Sat, 19 Nov 2011 04:31:08 -0800 (PST) In-Reply-To: <1321696641-14437-1-git-send-email-xiaoqiangnk@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Yongqiang Yang This patch adds a function named ext4_setup_new_desc() which sets up a new group descriptor and whose code is sopied from ext4_group_add(). The function will be used by new resize implementation. Signed-off-by: Yongqiang Yang Signed-off-by: "Theodore Ts'o" --- fs/ext4/resize.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 55 insertions(+), 0 deletions(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 9a5486e..a50eab3 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -777,6 +777,61 @@ out: return err; } +/* + * ext4_setup_new_desc() sets up group descriptors specified by @input. + * + * @handle: journal handle + * @sb: super block + */ +static int ext4_setup_new_desc(handle_t *handle, struct super_block *sb, + struct ext4_new_group_data *input) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_group_t group; + struct ext4_group_desc *gdp; + struct buffer_head *gdb_bh; + int gdb_off, gdb_num, err = 0; + + group = input->group; + + gdb_off = group % EXT4_DESC_PER_BLOCK(sb); + gdb_num = group / EXT4_DESC_PER_BLOCK(sb); + + /* + * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). + */ + gdb_bh = sbi->s_group_desc[gdb_num]; + /* Update group descriptor block for new group */ + gdp = (struct ext4_group_desc *)((char *)gdb_bh->b_data + + gdb_off * EXT4_DESC_SIZE(sb)); + + memset(gdp, 0, EXT4_DESC_SIZE(sb)); + /* LV FIXME */ + memset(gdp, 0, EXT4_DESC_SIZE(sb)); + ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */ + ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */ + ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */ + ext4_free_group_clusters_set(sb, gdp, + EXT4_B2C(sbi, input->free_blocks_count)); + ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); + gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED); + gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp); + + err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); + if (unlikely(err)) { + ext4_std_error(sb, err); + return err; + } + + /* + * We can allocate memory for mb_alloc based on the new group + * descriptor + */ + err = ext4_mb_add_groupinfo(sb, group, gdp); + + 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 -- 1.7.5.1