lloff_t Ext2Partition::extent_binarysearch(EXT4_EXTENT_HEADER *header, lloff_t lbn, bool isallocated)
{
EXT4_EXTENT *extent;
EXT4_EXTENT_IDX *index;
EXT4_EXTENT_HEADER *child;
lloff_t physical_block = 0;
lloff_t block;
if(header->eh_magic != EXT4_EXT_MAGIC)
{
LOG("Invalid magic in Extent Header: %X\n", header->eh_magic);
return 0;
}
extent = EXT_FIRST_EXTENT(header);
// LOG("HEADER: magic %x Entries: %d depth %d\n", header->eh_magic, header->eh_entries, header->eh_depth);
if(header->eh_depth == 0)
{
for(int i = 0; i < header->eh_entries; i++)
{
// LOG("EXTENT: Block: %d Length: %d LBN: %d\n", extent->ee_block, extent->ee_len, lbn);
if((lbn >= extent->ee_block) &&
(lbn < (extent->ee_block + extent->ee_len)))
{
physical_block = ext_to_block(extent) + lbn;
physical_block = physical_block - (lloff_t)extent->ee_block;
if(isallocated)
delete [] header;
// LOG("Physical Block: %d\n", physical_block);
return physical_block;
}
extent++; // Pointer increment by size of Extent.
}
return 0;
}
index = EXT_FIRST_INDEX(header);
for(int i = 0; i < header->eh_entries; i++)
{
// LOG("INDEX: Block: %d Leaf: %d \n", index->ei_block, index->ei_leaf_lo);
if((i == (header->eh_entries - 1)) ||
(lbn < (index + 1)->ei_block))
{
child = (EXT4_EXTENT_HEADER *) new char [blocksize];
block = idx_to_block(index);
ext2_readblock(block, (void *) child);
return extent_binarysearch(child, lbn, true);
}
index++;
}
// We reach here if we do not find the key
if(isallocated)
delete [] header;
return physical_block;
}
uint64_t Partition::ExtentBinarySearch(EXT4_EXTENT_HEADER *header, uint64_t lbn, bool isallocated)
{
EXT4_EXTENT *extent;
EXT4_EXTENT_IDX *index;
EXT4_EXTENT_HEADER *child;
uint64_t physical_block = 0;
uint64_t block;
if(header->eh_magic != EXT4_EXT_MAGIC)
{
LOG("Invalid magic in Extent Header: %X\n", header->eh_magic);
return 0;
}
extent = EXT_FIRST_EXTENT(header);
if(header->eh_depth == 0)
{
for(int i = 0; i < header->eh_entries; i++)
{
if((lbn >= extent->ee_block) &&
(lbn < (extent->ee_block + extent->ee_len)))
{
physical_block = ext_to_block(extent) + lbn;
physical_block = physical_block - (uint64_t)extent->ee_block;
if(isallocated)
delete [] header;
return physical_block;
}
extent++;
}
return 0;
}
index = EXT_FIRST_INDEX(header);
for(int i = 0; i < header->eh_entries; i++)
{
if(lbn >= index->ei_block)
{
child = (EXT4_EXTENT_HEADER *) new char [blocksize];
block = idx_to_block(index);
ReadBlock(block, (void *) child);
return ExtentBinarySearch(child, lbn, true);
}
}
if(isallocated)
delete [] header;
return physical_block;
}
