Files
ext4recovery/misc_tools/investigate_translation.py
2026-04-30 11:04:05 +00:00

40 lines
1.4 KiB
Python

CHUNK = 128*512 # 65536 bytes
BSIZE = 4096
# Working blocks:
# 9262 (root dir) -> chunk_idx=3, works
# 6300141 (volumes) -> chunk_idx=3, works
# 6299897 (ptero) -> chunk_idx=3, works
# Failing block:
# 5251104 (var) -> chunk_idx=4, fails
# All working blocks have chunk_idx=3
# The failing block has chunk_idx=4
# What if the issue isn't our translation formula
# but that block 5251104 was written when the filesystem
# was mounted through the PERC, and the PERC stored it
# in a way we can't access without the controller?
# Let's find MORE blocks that work to see if chunk_idx matters:
# Check the /boot, /home, /usr directories
import subprocess, struct
for path, inode in [('boot',2621441), ('home',2097153), ('usr',5505025),
('etc',4456449), ('tmp',786433)]:
r = subprocess.run(['istat','/dev/nbd0',str(inode)],
capture_output=True, text=True)
for line in r.stdout.splitlines():
if 'Direct Blocks' in line:
pass
elif line.strip() and all(c.isdigit() or c==' ' for c in line.strip()):
blocks = [int(x) for x in line.split() if x.strip()]
for b in blocks:
virt = b * BSIZE
group = virt // (5*CHUNK)
in_group = virt % (5*CHUNK)
chunk_idx = in_group // CHUNK
print(f'/{path} block={b} chunk_idx={chunk_idx}')