55 lines
1.7 KiB
Python
55 lines
1.7 KiB
Python
import struct
|
|
|
|
CHUNK = 128*512
|
|
LV_START = 5120000*512
|
|
BSIZE = 4096
|
|
BPG = 32768
|
|
|
|
def read_virt(virt_byte, length):
|
|
result = bytearray(length)
|
|
pos = virt_byte
|
|
remaining = length
|
|
with open('/dev/md0','rb') as f:
|
|
while remaining > 0:
|
|
group = pos // (5*CHUNK)
|
|
in_group = pos % (5*CHUNK)
|
|
chunk_idx = in_group // CHUNK
|
|
intra = in_group % CHUNK
|
|
seg_len = min(CHUNK-intra, remaining)
|
|
dst_off = pos - virt_byte
|
|
if chunk_idx != 4:
|
|
phys = LV_START + group*4*CHUNK + chunk_idx*CHUNK + intra
|
|
f.seek(phys)
|
|
data = f.read(seg_len)
|
|
result[dst_off:dst_off+len(data)] = data
|
|
pos += seg_len
|
|
remaining -= seg_len
|
|
return bytes(result)
|
|
|
|
# Load GDT
|
|
NUM_GROUPS = 35728
|
|
gdt_data = read_virt(BSIZE, NUM_GROUPS*64)
|
|
|
|
def get_block_bitmap_block(group):
|
|
entry = gdt_data[group*64:(group+1)*64]
|
|
bb_lo = struct.unpack_from('<I', entry, 0)[0]
|
|
bb_hi = struct.unpack_from('<I', entry, 32)[0]
|
|
return (bb_hi<<32)|bb_lo
|
|
|
|
def is_block_allocated(block_num):
|
|
group = block_num // BPG
|
|
offset = block_num % BPG
|
|
bb_block = get_block_bitmap_block(group)
|
|
bitmap = read_virt(bb_block*BSIZE, BSIZE)
|
|
byte_idx = offset // 8
|
|
bit_idx = offset % 8
|
|
return bool(bitmap[byte_idx] & (1 << bit_idx))
|
|
|
|
for block, name in [(6300141,'volumes'), (6299897,'pterodactyl'), (5251104,'var')]:
|
|
allocated = is_block_allocated(block)
|
|
virt = block * BSIZE
|
|
in_group = virt % (5*CHUNK)
|
|
chunk_idx = in_group // CHUNK
|
|
print(f'{name:15s} block={block:8d} chunk_idx={chunk_idx} '
|
|
f'allocated={allocated}')
|