1 files changed, 132 insertions, 0 deletions

diff --git a/archinstall/lib/disk/btrfs/btrfs_helpers.py b/archinstall/lib/disk/btrfs/btrfs_helpers.py
new file mode 100644
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--- /dev/null
+++ b/archinstall/lib/disk/btrfs/btrfs_helpers.py
@@ -0,0 +1,132 @@
+import pathlib
+import logging
+from typing import Optional
+
+from ...exceptions import SysCallError, DiskError
+from ...general import SysCommand
+from ...output import log
+from ..helpers import get_mount_info
+from .btrfssubvolume import BtrfsSubvolume
+
+
+def mount_subvolume(installation, device, name, subvolume_information):
+	# we normalize the subvolume name (getting rid of slash at the start if exists. In our implemenation has no semantic load.
+	# Every subvolume is created from the top of the hierarchy- and simplifies its further use
+	name = name.lstrip('/')
+
+	# renormalize the right hand.
+	mountpoint = subvolume_information.get('mountpoint', None)
+	if not mountpoint:
+		return None
+
+	if type(mountpoint) == str:
+		mountpoint = pathlib.Path(mountpoint)
+
+	installation_target = installation.target
+	if type(installation_target) == str:
+		installation_target = pathlib.Path(installation_target)
+
+	mountpoint = installation_target / mountpoint.relative_to(mountpoint.anchor)
+	mountpoint.mkdir(parents=True, exist_ok=True)
+
+	mount_options = subvolume_information.get('options', [])
+	if not any('subvol=' in x for x in mount_options):
+		mount_options += [f'subvol={name}']
+
+	log(f"Mounting subvolume {name} on {device} to {mountpoint}", level=logging.INFO, fg="gray")
+	SysCommand(f"mount {device.path} {mountpoint} -o {','.join(mount_options)}")
+
+
+def setup_subvolumes(installation, partition_dict):
+	"""
+	Taken from: ..user_guides.py
+
+	partition['btrfs'] = {
+		"subvolumes" : {
+			"@":           "/",
+			"@home":       "/home",
+			"@log":        "/var/log",
+			"@pkg":        "/var/cache/pacman/pkg",
+			"@.snapshots": "/.snapshots"
+		}
+	}
+	"""
+	log(f"Setting up subvolumes: {partition_dict['btrfs']['subvolumes']}", level=logging.INFO, fg="gray")
+	for name, right_hand in partition_dict['btrfs']['subvolumes'].items():
+		# we normalize the subvolume name (getting rid of slash at the start if exists. In our implemenation has no semantic load.
+		# Every subvolume is created from the top of the hierarchy- and simplifies its further use
+		name = name.lstrip('/')
+
+		# renormalize the right hand.
+		# mountpoint = None
+		subvol_options = []
+
+		match right_hand:
+			# case str(): # backwards-compatability
+			# 	mountpoint = right_hand
+			case dict():
+				# mountpoint = right_hand.get('mountpoint', None)
+				subvol_options = right_hand.get('options', [])
+
+		# We create the subvolume using the BTRFSPartition instance.
+		# That way we ensure not only easy access, but also accurate mount locations etc.
+		partition_dict['device_instance'].create_subvolume(name, installation=installation)
+
+		# Make the nodatacow processing now
+		# It will be the main cause of creation of subvolumes which are not to be mounted
+		# it is not an options which can be established by subvolume (but for whole file systems), and can be
+		# set up via a simple attribute change in a directory (if empty). And here the directories are brand new
+		if 'nodatacow' in subvol_options:
+			if (cmd := SysCommand(f"chattr +C {installation.target}/{name}")).exit_code != 0:
+				raise DiskError(f"Could not set  nodatacow attribute at {installation.target}/{name}: {cmd}")
+			# entry is deleted so nodatacow doesn't propagate to the mount options
+			del subvol_options[subvol_options.index('nodatacow')]
+		# Make the compress processing now
+		# it is not an options which can be established by subvolume (but for whole file systems), and can be
+		# set up via a simple attribute change in a directory (if empty). And here the directories are brand new
+		# in this way only zstd compression is activaded
+		# TODO WARNING it is not clear if it should be a standard feature, so it might need to be deactivated
+
+		if 'compress' in subvol_options:
+			if not any(['compress' in filesystem_option for filesystem_option in partition_dict.get('filesystem', {}).get('mount_options', [])]):
+				if (cmd := SysCommand(f"chattr +c {installation.target}/{name}")).exit_code != 0:
+					raise DiskError(f"Could not set compress attribute at {installation.target}/{name}: {cmd}")
+			# entry is deleted so compress doesn't propagate to the mount options
+			del subvol_options[subvol_options.index('compress')]
+
+def subvolume_info_from_path(path :pathlib.Path) -> Optional[BtrfsSubvolume]:
+	try:
+		subvolume_name = None
+		result = {}
+		for index, line in enumerate(SysCommand(f"btrfs subvolume show {path}")):
+			if index == 0:
+				subvolume_name = line.strip().decode('UTF-8')
+				continue
+
+			if b':' in line:
+				key, value = line.strip().decode('UTF-8').split(':', 1)
+
+				# A bit of a hack, until I figure out how @dataclass
+				# allows for hooking in a pre-processor to do this we have to do it here:
+				result[key.lower().replace(' ', '_').replace('(s)', 's')] = value.strip()
+
+		return BtrfsSubvolume(**{'full_path' : path, 'name' : subvolume_name, **result})
+
+	except SysCallError:
+		pass
+
+	return None
+
+def find_parent_subvolume(path :pathlib.Path, filters=[]):
+	# A root path cannot have a parent
+	if str(path) == '/':
+		return None
+
+	if found_mount := get_mount_info(str(path.parent), traverse=True, ignore=filters):
+		if not (subvolume := subvolume_info_from_path(found_mount['target'])):
+			if found_mount['target'] == '/':
+				return None
+
+			return find_parent_subvolume(path.parent, traverse=True, filters=[*filters, found_mount['target']])
+
+		return subvolume
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