errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish,
int num, ext2fs_block_bitmap map, blk64_t *ret)
{
blk64_t b = start;
int c_ratio;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!b)
b = fs->super->s_first_data_block;
if (!finish)
finish = start;
if (!num)
num = 1;
c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
b &= ~(c_ratio - 1);
finish &= ~(c_ratio -1);
do {
if (b+num-1 > ext2fs_blocks_count(fs->super))
b = fs->super->s_first_data_block;
if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) {
*ret = b;
return 0;
}
b += c_ratio;
} while (b != finish);
return EXT2_ET_BLOCK_ALLOC_FAIL;
}
errcode_t ext2fs_convert_subcluster_bitmap(ext2_filsys fs,
ext2fs_block_bitmap *bitmap)
{
ext2fs_block_bitmap cmap, bmap;
errcode_t retval;
blk64_t i, b_end, c_end;
int n, ratio;
bmap = *bitmap;
if (fs->cluster_ratio_bits == ext2fs_get_bitmap_granularity(bmap))
return 0; /* Nothing to do */
retval = ext2fs_allocate_block_bitmap(fs, "converted cluster bitmap",
&cmap);
if (retval)
return retval;
i = bmap->start;
b_end = bmap->end;
bmap->end = bmap->real_end;
c_end = cmap->end;
cmap->end = cmap->real_end;
n = 0;
ratio = 1 << fs->cluster_ratio_bits;
while (i < bmap->real_end) {
if (ext2fs_test_block_bitmap2(bmap, i)) {
ext2fs_mark_block_bitmap2(cmap, i);
i += ratio - n;
n = 0;
continue;
}
i++; n++;
if (n >= ratio)
n = 0;
}
bmap->end = b_end;
cmap->end = c_end;
ext2fs_free_block_bitmap(bmap);
*bitmap = cmap;
return 0;
}
/*
* Stupid algorithm --- we now just search forward starting from the
* goal. Should put in a smarter one someday....
*/
errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
ext2fs_block_bitmap map, blk64_t *ret)
{
blk64_t i;
int c_ratio;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!goal || (goal >= ext2fs_blocks_count(fs->super)))
goal = fs->super->s_first_data_block;
i = goal;
c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
if (c_ratio > 1)
goal &= ~EXT2FS_CLUSTER_MASK(fs);
check_block_uninit(fs, map,
(i - fs->super->s_first_data_block) /
EXT2_BLOCKS_PER_GROUP(fs->super));
do {
if (((i - fs->super->s_first_data_block) %
EXT2_BLOCKS_PER_GROUP(fs->super)) == 0)
check_block_uninit(fs, map,
(i - fs->super->s_first_data_block) /
EXT2_BLOCKS_PER_GROUP(fs->super));
if (!ext2fs_fast_test_block_bitmap2(map, i)) {
*ret = i;
return 0;
}
i = (i + c_ratio) & ~(c_ratio - 1);
if (i >= ext2fs_blocks_count(fs->super))
i = fs->super->s_first_data_block;
} while (i != goal);
return EXT2_ET_BLOCK_ALLOC_FAIL;
}
