pmbootstrap-meow/pmb/chroot/mount.py
Caleb Connolly 866e5bcfab
core: add an Arch type (MR 2252)
Move pmb/parse/arch.py over to core and refactor it as an Arch type,
similar to how Chroot was done. Fix all the uses (that I can find) of
arch in the codebase that need adjusting.

The new Arch type is an Enum, making it clear what architectures can be
represented and making it much easier to reason about. Since we support
~5 (kinda) different representations of an Architecture (Alpine, Kernel,
target triple, platform, and QEMU), we now formalise that the Alpine
format is what we represent internally, with methods to convert to any
of the others as-needed.

Signed-off-by: Caleb Connolly <caleb@postmarketos.org>
2024-06-23 12:38:39 +02:00

127 lines
4.8 KiB
Python

# Copyright 2023 Oliver Smith
# SPDX-License-Identifier: GPL-3.0-or-later
from pmb.helpers import logging
import os
from pathlib import Path
from typing import Dict
import pmb.config
import pmb.chroot.apk
from pmb.types import PmbArgs
import pmb.helpers.run
import pmb.parse
import pmb.helpers.mount
from pmb.core import Chroot, get_context
def create_device_nodes(chroot: Chroot):
"""
Create device nodes for null, zero, full, random, urandom in the chroot.
"""
try:
# Create all device nodes as specified in the config
for dev in pmb.config.chroot_device_nodes:
path = chroot / "dev" / str(dev[4])
if not path.exists():
pmb.helpers.run.root(["mknod",
"-m", str(dev[0]), # permissions
path, # name
str(dev[1]), # type
str(dev[2]), # major
str(dev[3]), # minor
])
# Verify major and minor numbers of created nodes
for dev in pmb.config.chroot_device_nodes:
path = chroot / "dev" / str(dev[4])
stat_result = path.stat()
rdev = stat_result.st_rdev
assert os.major(rdev) == dev[2], f"Wrong major in {path}"
assert os.minor(rdev) == dev[3], f"Wrong minor in {path}"
# Verify /dev/zero reading and writing
path = chroot / "dev/zero"
with open(path, "r+b", 0) as handle:
assert handle.write(bytes([0xff])), f"Write failed for {path}"
assert handle.read(1) == bytes([0x00]), f"Read failed for {path}"
# On failure: Show filesystem-related error
except Exception as e:
logging.info(str(e) + "!")
raise RuntimeError(f"Failed to create device nodes in the '{chroot}' chroot.")
def mount_dev_tmpfs(chroot: Chroot=Chroot.native()):
"""
Mount tmpfs inside the chroot's dev folder to make sure we can create
device nodes, even if the filesystem of the work folder does not support
it.
"""
# Do nothing when it is already mounted
dev = chroot / "dev"
if pmb.helpers.mount.ismount(dev):
return
# Create the $chroot/dev folder and mount tmpfs there
pmb.helpers.run.root(["mkdir", "-p", dev])
pmb.helpers.run.root(["mount", "-t", "tmpfs",
"-o", "size=1M,noexec,dev",
"tmpfs", dev])
# Create pts, shm folders and device nodes
pmb.helpers.run.root(["mkdir", "-p", dev / "pts", dev / "shm"])
pmb.helpers.run.root(["mount", "-t", "tmpfs",
"-o", "nodev,nosuid,noexec",
"tmpfs", dev / "shm"])
create_device_nodes(chroot)
# Setup /dev/fd as a symlink
pmb.helpers.run.root(["ln", "-sf", "/proc/self/fd", f"{dev}/"])
def mount(chroot: Chroot):
# Mount tmpfs as the chroot's /dev
mount_dev_tmpfs(chroot)
# Get all mountpoints
arch = chroot.arch
channel = pmb.config.pmaports.read_config(support_systemd=False)["channel"]
mountpoints: Dict[Path, Path] = {}
for src_template, target_template in pmb.config.chroot_mount_bind.items():
src_template = src_template.replace("$WORK", os.fspath(get_context().config.work))
src_template = src_template.replace("$ARCH", str(arch))
src_template = src_template.replace("$CHANNEL", channel)
mountpoints[Path(src_template)] = Path(target_template)
# Mount if necessary
for source, target in mountpoints.items():
target_outer = chroot / target
#raise RuntimeError("test")
pmb.helpers.mount.bind(source, target_outer)
def mount_native_into_foreign(chroot: Chroot):
source = Chroot.native().path
target = chroot / "native"
pmb.helpers.mount.bind(source, target)
musl = next(source.glob("lib/ld-musl-*.so.1")).name
musl_link = (chroot / "lib" / musl)
if not musl_link.is_symlink():
pmb.helpers.run.root(["ln", "-s", "/native/lib/" + musl,
musl_link])
pmb.helpers.run.root(args, ["ln", "-sf", "/native/usr/bin/pigz", "/usr/local/bin/pigz"])
def remove_mnt_pmbootstrap(args: PmbArgs, chroot: Chroot):
""" Safely remove /mnt/pmbootstrap directories from the chroot, without
running rm -r as root and potentially removing data inside the
mountpoint in case it was still mounted (bug in pmbootstrap, or user
ran pmbootstrap 2x in parallel). This is similar to running 'rm -r -d',
but we don't assume that the host's rm has the -d flag (busybox does
not). """
mnt_dir = chroot / "mnt/pmbootstrap"
if not mnt_dir.exists():
return
for path in list(mnt_dir.glob("*")) + [mnt_dir]:
pmb.helpers.run.root(["rmdir", path])