示例#1
0
struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb,
					     unsigned int block_group,
					     struct buffer_head ** bh)
{
	unsigned long group_desc;
	unsigned long desc;
	struct ext3_group_desc * gdp;

	if (block_group >= EXT3_SB(sb)->s_groups_count) {
		ext3_error (sb, "ext3_get_group_desc",
			    "block_group >= groups_count - "
			    "block_group = %d, groups_count = %lu",
			    block_group, EXT3_SB(sb)->s_groups_count);

		return NULL;
	}
	smp_rmb();

	group_desc = block_group / EXT3_DESC_PER_BLOCK(sb);
	desc = block_group % EXT3_DESC_PER_BLOCK(sb);
	if (!EXT3_SB(sb)->s_group_desc[group_desc]) {
		ext3_error (sb, "ext3_get_group_desc",
			    "Group descriptor not loaded - "
			    "block_group = %d, group_desc = %lu, desc = %lu",
			     block_group, group_desc, desc);
		return NULL;
	}

	gdp = (struct ext3_group_desc *) 
	      EXT3_SB(sb)->s_group_desc[group_desc]->b_data;
	if (bh)
		*bh = EXT3_SB(sb)->s_group_desc[group_desc];
	return gdp + desc;
}
示例#2
0
文件: balloc.c 项目: kzlin129/tt-gpl
struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb,
					     unsigned int block_group,
					     struct buffer_head ** bh)
{
	unsigned long group_desc;
	unsigned long offset;
	struct ext3_group_desc * desc;
	struct ext3_sb_info *sbi = EXT3_SB(sb);

	if (block_group >= sbi->s_groups_count) {
		ext3_error (sb, "ext3_get_group_desc",
			    "block_group >= groups_count - "
			    "block_group = %d, groups_count = %lu",
			    block_group, sbi->s_groups_count);

		return NULL;
	}
	smp_rmb();

	group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
	offset = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
	if (!sbi->s_group_desc[group_desc]) {
		ext3_error (sb, "ext3_get_group_desc",
			    "Group descriptor not loaded - "
			    "block_group = %d, group_desc = %lu, desc = %lu",
			     block_group, group_desc, offset);
		return NULL;
	}

	desc = (struct ext3_group_desc *) sbi->s_group_desc[group_desc]->b_data;
	if (bh)
		*bh = sbi->s_group_desc[group_desc];
	return desc + offset;
}