From 083f5b24cc55448e0602a807a5c2872e1f3796e2 Mon Sep 17 00:00:00 2001 From: Yongqiang Yang Date: Tue, 3 Jan 2012 23:37:31 -0500 Subject: ext4: add a function which sets up a block group descriptors of a flex bg This patch adds a function named ext4_setup_new_descs which sets up the block group descriptors of a flex bg. Signed-off-by: Yongqiang Yang Signed-off-by: "Theodore Ts'o" --- fs/ext4/resize.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) (limited to 'fs/ext4') diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index e8ccb2f8f45..098bdb8e97c 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1086,6 +1086,62 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, return err; } +/* + * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg + */ +static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, + struct ext4_new_flex_group_data *flex_gd) +{ + struct ext4_new_group_data *group_data = flex_gd->groups; + struct ext4_group_desc *gdp; + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct buffer_head *gdb_bh; + ext4_group_t group; + __u16 *bg_flags = flex_gd->bg_flags; + int i, gdb_off, gdb_num, err = 0; + + + for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { + group = group_data->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)); + ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); + ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); + ext4_inode_table_set(sb, gdp, group_data->inode_table); + ext4_free_group_clusters_set(sb, gdp, + EXT4_B2C(sbi, group_data->free_blocks_count)); + ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); + gdp->bg_flags = cpu_to_le16(*bg_flags); + gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); + + err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); + if (unlikely(err)) { + ext4_std_error(sb, err); + break; + } + + /* + * We can allocate memory for mb_alloc based on the new group + * descriptor + */ + err = ext4_mb_add_groupinfo(sb, group, gdp); + if (err) + break; + } + 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 -- cgit v1.2.3