static int ext2_check_descriptors (struct super_block * sb)
{
int i;
int desc_block = 0;
struct ext2_sb_info *sbi = EXT2_SB(sb);
struct ext2_group_desc * gdp = NULL;
ext2_debug ("Checking group descriptors");
for (i = 0; i < sbi->s_groups_count; i++)
{
ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
ext2_fsblk_t last_block;
if (i == sbi->s_groups_count - 1)
last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
else
last_block = first_block +
(EXT2_BLOCKS_PER_GROUP(sb) - 1);
if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
le32_to_cpu(gdp->bg_block_bitmap) > last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Block bitmap for group %d"
" not in group (block %lu)!",
i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
return 0;
}
if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Inode bitmap for group %d"
" not in group (block %lu)!",
i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
return 0;
}
if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Inode table for group %d"
" not in group (block %lu)!",
i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
return 0;
}
gdp++;
}
return 1;
}
/**
* goal_in_my_reservation()
* @rsv: inode's reservation window
* @grp_goal: given goal block relative to the allocation block group
* @group: the current allocation block group
* @sb: filesystem super block
*
* Test if the given goal block (group relative) is within the file's
* own block reservation window range.
*
* If the reservation window is outside the goal allocation group, return 0;
* grp_goal (given goal block) could be -1, which means no specific
* goal block. In this case, always return 1.
* If the goal block is within the reservation window, return 1;
* otherwise, return 0;
*/
static int
goal_in_my_reservation(struct ext2_reserve_window *rsv, ext2_grpblk_t grp_goal,
unsigned int group, struct super_block * sb)
{
ext2_fsblk_t group_first_block, group_last_block;
group_first_block = ext2_group_first_block_no(sb, group);
group_last_block = group_first_block + EXT2_BLOCKS_PER_GROUP(sb) - 1;
if ((rsv->_rsv_start > group_last_block) ||
(rsv->_rsv_end < group_first_block))
return 0;
if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start)
|| (grp_goal + group_first_block > rsv->_rsv_end)))
return 0;
return 1;
}
static unsigned long descriptor_loc(struct super_block *sb,
unsigned long logic_sb_block,
int nr)
{
struct ext2_sb_info *sbi = EXT2_SB(sb);
unsigned long bg, first_meta_bg;
int has_super = 0;
first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
nr < first_meta_bg)
return (logic_sb_block + nr + 1);
bg = sbi->s_desc_per_block * nr;
if (ext2_bg_has_super(sb, bg))
has_super = 1;
return ext2_group_first_block_no(sb, bg) + has_super;
}
static int ext2_valid_block_bitmap(struct super_block *sb,
struct ext2_group_desc *desc,
unsigned int block_group,
struct buffer_head *bh)
{
ext2_grpblk_t offset;
ext2_grpblk_t next_zero_bit;
ext2_fsblk_t bitmap_blk;
ext2_fsblk_t group_first_block;
group_first_block = ext2_group_first_block_no(sb, block_group);
/* check whether block bitmap block number is set */
bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
offset = bitmap_blk - group_first_block;
if (!ext2_test_bit(offset, bh->b_data))
/* bad block bitmap */
goto err_out;
/* check whether the inode bitmap block number is set */
bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
offset = bitmap_blk - group_first_block;
if (!ext2_test_bit(offset, bh->b_data))
/* bad block bitmap */
goto err_out;
/* check whether the inode table block number is set */
bitmap_blk = le32_to_cpu(desc->bg_inode_table);
offset = bitmap_blk - group_first_block;
next_zero_bit = ext2_find_next_zero_bit(bh->b_data,
offset + EXT2_SB(sb)->s_itb_per_group,
offset);
if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group)
/* good bitmap for inode tables */
return 1;
err_out:
ext2_error(sb, __func__,
"Invalid block bitmap - "
"block_group = %d, block = %lu",
block_group, bitmap_blk);
return 0;
}
