forked from Mirror/pmbootstrap
f21c216a26
While at it, also remove unnecessary "#!/usr/bin/env python3" in files that only get imported, and adjust other empty/comment lines in the beginnings of the files for consistency. This makes files easier to read, and makes the pmbootstrap codebase more consistent with the build.postmarketos.org codebase.
108 lines
3.4 KiB
Python
108 lines
3.4 KiB
Python
# Copyright 2020 Oliver Smith
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# SPDX-License-Identifier: GPL-3.0-or-later
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import os
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import pmb.helpers.run
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def ismount(folder):
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"""
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Ismount() implementation, that works for mount --bind.
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Workaround for: https://bugs.python.org/issue29707
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"""
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folder = os.path.realpath(os.path.realpath(folder))
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with open("/proc/mounts", "r") as handle:
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for line in handle:
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words = line.split()
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if len(words) >= 2 and words[1] == folder:
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return True
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if words[0] == folder:
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return True
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return False
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def bind(args, source, destination, create_folders=True, umount=False):
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"""
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Mount --bind a folder and create necessary directory structure.
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:param umount: when destination is already a mount point, umount it first.
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"""
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# Check/umount destination
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if ismount(destination):
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if umount:
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umount_all(args, destination)
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else:
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return
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# Check/create folders
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for path in [source, destination]:
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if os.path.exists(path):
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continue
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if create_folders:
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pmb.helpers.run.root(args, ["mkdir", "-p", path])
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else:
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raise RuntimeError("Mount failed, folder does not exist: " +
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path)
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# Actually mount the folder
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pmb.helpers.run.root(args, ["mount", "--bind", source, destination])
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# Verify, that it has worked
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if not ismount(destination):
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raise RuntimeError("Mount failed: " + source + " -> " + destination)
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def bind_file(args, source, destination, create_folders=False):
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"""
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Mount a file with the --bind option, and create the destination file,
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if necessary.
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"""
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# Skip existing mountpoint
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if ismount(destination):
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return
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# Create empty file
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if not os.path.exists(destination):
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if create_folders:
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dir = os.path.dirname(destination)
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if not os.path.isdir(dir):
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pmb.helpers.run.root(args, ["mkdir", "-p", dir])
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pmb.helpers.run.root(args, ["touch", destination])
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# Mount
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pmb.helpers.run.root(args, ["mount", "--bind", source,
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destination])
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def umount_all_list(prefix, source="/proc/mounts"):
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"""
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Parses `/proc/mounts` for all folders beginning with a prefix.
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:source: can be changed for testcases
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:returns: a list of folders, that need to be umounted
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"""
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ret = []
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prefix = os.path.realpath(prefix)
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with open(source, "r") as handle:
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for line in handle:
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words = line.split()
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if len(words) < 2:
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raise RuntimeError("Failed to parse line in " + source + ": " +
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line)
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mountpoint = words[1]
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if mountpoint.startswith(prefix):
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# Remove "\040(deleted)" suffix (#545)
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deleted_str = r"\040(deleted)"
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if mountpoint.endswith(deleted_str):
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mountpoint = mountpoint[:-len(deleted_str)]
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ret.append(mountpoint)
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ret.sort(reverse=True)
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return ret
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def umount_all(args, folder):
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"""
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Umount all folders, that are mounted inside a given folder.
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"""
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for mountpoint in umount_all_list(folder):
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pmb.helpers.run.root(args, ["umount", mountpoint])
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if ismount(mountpoint):
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raise RuntimeError("Failed to umount: " + mountpoint)
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