2e09e7937c
Move the mount and umount helpers to the new mount utility module. No semantic change in the function.
75 lines
2 KiB
Python
75 lines
2 KiB
Python
"""Mount utilities
|
|
"""
|
|
|
|
import contextlib
|
|
import subprocess
|
|
|
|
|
|
def mount(source, target, bind=True, ro=True, private=True, mode="0755"):
|
|
options = []
|
|
if ro:
|
|
options += ["ro"]
|
|
if mode:
|
|
options += [mode]
|
|
|
|
args = []
|
|
if bind:
|
|
args += ["--rbind"]
|
|
if private:
|
|
args += ["--make-rprivate"]
|
|
if options:
|
|
args += ["-o", ",".join(options)]
|
|
|
|
r = subprocess.run(["mount"] + args + [source, target],
|
|
stderr=subprocess.STDOUT,
|
|
stdout=subprocess.PIPE,
|
|
encoding="utf-8",
|
|
check=False)
|
|
|
|
if r.returncode != 0:
|
|
code = r.returncode
|
|
msg = r.stdout.strip()
|
|
raise RuntimeError(f"{msg} (code: {code})")
|
|
|
|
|
|
def umount(target, lazy=False):
|
|
args = []
|
|
if lazy:
|
|
args += ["--lazy"]
|
|
subprocess.run(["sync", "-f", target], check=True)
|
|
subprocess.run(["umount", "-R"] + args + [target], check=True)
|
|
|
|
|
|
class MountGuard(contextlib.AbstractContextManager):
|
|
def __init__(self):
|
|
self.mounts = []
|
|
|
|
def mount(self, source, target, bind=True, ro=False, mode="0755"):
|
|
options = []
|
|
if bind:
|
|
options += ["bind"]
|
|
if ro:
|
|
options += ["ro"]
|
|
if mode:
|
|
options += [mode]
|
|
|
|
args = ["--make-private"]
|
|
if options:
|
|
args += ["-o", ",".join(options)]
|
|
|
|
subprocess.run(["mount"] + args + [source, target], check=True)
|
|
self.mounts += [{"source": source, "target": target}]
|
|
|
|
def umount(self):
|
|
|
|
while self.mounts:
|
|
mnt = self.mounts.pop() # FILO: get the last mount
|
|
target = mnt["target"]
|
|
# The sync should in theory not be needed but in rare
|
|
# cases `target is busy` error has been spotted.
|
|
# Calling `sync` does not hurt so we keep it for now.
|
|
subprocess.run(["sync", "-f", target], check=True)
|
|
subprocess.run(["umount", target], check=True)
|
|
|
|
def __exit__(self, exc_type, exc_val, exc_tb):
|
|
self.umount()
|