/* alloc a new block */
int ext2_alloc_block ( unsigned int goal)
{
unsigned int block;
unsigned int block_group;
unsigned int bit;
struct ext2_group_desc *desc;
struct ext2_sb_info * sbi = EXT2_SBI();
void *bitmap;
block_group = ext2_get_group_num (goal, BLOCK);
bit = ext2_get_group_offset (goal, BLOCK);
bitmap = ext2_read_block_bitmap (block_group);
block = ext2_grab_block (bitmap, bit);
if ( !block)
ext2_error ("no free blocks any more");
desc = ext2_get_group_desc (block_group);
desc->bg_free_blocks_count --;
sbi->s_free_blocks_count --;
ext2_set_bit (bitmap, block);
return block;
}
/*
* This function zeros out the allocated block, and updates all of the
* appropriate filesystem records.
*/
bool ext2_alloc_block(PEXT2_FILESYS fs, ULONG goal, ULONG *ret)
{
bool retval;
ULONG block;
char *buf = NULL;
buf = (char *)RtlAllocateHeap(RtlGetProcessHeap(), HEAP_ZERO_MEMORY, fs->blocksize);
if (!buf)
return false;
if (!fs->block_map)
{
retval = ext2_read_block_bitmap(fs);
if (!retval)
goto fail;
}
retval = ext2_new_block(fs, goal, 0, &block);
if (!retval)
goto fail;
retval = NT_SUCCESS(Ext2WriteDisk(
fs,
((LONGLONG)block * fs->blocksize),
fs->blocksize, (unsigned char *)buf));
if (!retval)
{
goto fail;
}
ext2_block_alloc_stats(fs, block, +1);
*ret = block;
if (buf)
{
RtlFreeHeap(RtlGetProcessHeap(), 0, buf);
}
return true;
fail:
if (buf)
{
RtlFreeHeap(RtlGetProcessHeap(), 0, buf);
}
return false;
}
/* free the goal block, clean it */
void ext2_free_block(unsigned int block)
{
unsigned int block_group;
unsigned int bit;
struct ext2_group_desc *desc;
struct ext2_sb_info * sbi = EXT2_SBI();
void * bitmap;
block_group = ext2_get_group_num (block, BLOCK);
bit = ext2_get_group_offset (block, BLOCK);
desc = ext2_get_group_desc (block_group);
bitmap = ext2_read_block_bitmap (block_group);
if ( !ext2_clear_bit(bitmap, bit) )
ext2_error("bit %d (%d) alread cleard", bit, block_group);
desc->bg_free_blocks_count ++;
sbi->s_free_blocks_count ++;
}