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ext4: add a function which sets up a block group descriptors of a flex bg

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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 <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Yongqiang Yang 2012-01-03 23:37:31 -05:00 committed by Theodore Ts'o
parent 33afdcc540
commit 083f5b24cc
1 changed files with 56 additions and 0 deletions
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56
fs/ext4/resize.c
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@ -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