56 lines
1.3 KiB
Python
56 lines
1.3 KiB
Python
import json
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from pathlib import Path
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from consts import DATA_DIR
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from util import run, run_out
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def img_dir(volume_id):
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return Path(f"{DATA_DIR}/{volume_id}")
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def meta_file(volume_id):
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return Path(f"{img_dir(volume_id)}/disk.meta")
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def metadata(volume_id):
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try:
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return json.loads(meta_file(volume_id).read_text())
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except FileNotFoundError:
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return {}
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def img_file(volume_id):
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return Path(metadata(volume_id)["img_file"])
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def patch_metadata(volume_id, obj):
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old_data = metadata(volume_id)
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new_data = {**old_data, **obj}
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meta_file(volume_id).write_text(json.dumps(new_data))
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return new_data
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def attached_loops(file: str) -> [str]:
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out = run_out(f"losetup -j {file}").stdout.decode()
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lines = out.splitlines()
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devs = [line.split(":", 1)[0] for line in lines]
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return devs
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def attach_loop(file) -> str:
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def next_loop():
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loop_file = run_out(f"losetup -f").stdout.decode().strip()
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if not Path(loop_file).exists():
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pfx_len = len("/dev/loop")
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loop_dev_id = loop_file[pfx_len:]
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run(f"mknod {loop_file} b 7 {loop_dev_id}")
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return loop_file
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while True:
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devs = attached_loops(file)
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if len(devs) > 0:
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return devs[0]
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next_loop()
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run(f"losetup -f {file}")
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