path: root/src/Partitioning.py

# Copyright 1999-2006 Gentoo Foundation
# This source code is distributed under the terms of version 2 of the GNU
# General Public License as published by the Free Software Foundation, a copy
# of which can be found in the main directory of this project.

import commands, string, os, parted, copy
from glob import glob
from GLIException import *
import GLIUtility
import time

MEGABYTE = 1024 * 1024

supported_filesystems = {
  'all':   ( 'ext2', 'ext3', 'linux-swap', 'xfs', 'jfs', 'reiserfs' ),
  'x86':   ( 'ntfs', 'fat16', 'fat32' ),
  'amd64': ( 'ntfs', 'fat16', 'fat32' ),
  'ppc':   ( 'reiserfs', 'apple_bootstrap', 'hfs' )
}

labelinfo = {
  'msdos': { 'ignoredparts': [], 'extended': True },
  'mac':   { 'ignoredparts': [1], 'extended': False },
  'sun':   { 'ignoredparts': [3], 'extended': False },
  'loop':  { 'ignoredparts': [], 'extended': False }
}

archinfo = {
  'sparc': 'sun',
  'hppa': 'msdos',
  'x86': 'msdos',
  'amd64': 'msdos',
  'ppc': 'mac'
}

parted_type_map = {
  'linux-swap': 'swap'
}

##
# This class provides a partitioning abstraction for the frontends
class Device:
	"Class representing a partitionable device."
	
	_device = None
	_partitions = None
	_geometry = None
	_parted_dev = None
	_parted_disk = None
	_arch = None
	_disklabel = None
	_install_profile = None

	##
	# Initialization function for Device class
	# @param device Device node (e.g. /dev/hda) of device being represented
	# @param arch Architecture that we're partition for (defaults to 'x86' for now)
	def __init__(self, device, arch, install_profile):
		self._device = device
		self._arch = arch
		self._partitions = []
		self._geometry = {}
		self._parted_dev = parted.PedDevice.get(self._device)
		try:
			self._parted_disk = parted.PedDisk.new(self._parted_dev)
		except:
			self._parted_disk = self._parted_dev.disk_new_fresh(parted.disk_type_get(archinfo[self._arch]))
		self._disklabel = self._parted_disk.type.name
		self._labelinfo = labelinfo[self._disklabel]
		self.set_disk_geometry_from_disk()
		self.set_partitions_from_disk()
		self._install_profile = install_profile

	def __getitem__(self, name):
		return self.get_partition(name)

	def __iter__(self):
		for part in self.get_partitions():
			yield part

	##
	# Returns list of supported filesystems based on arch
	def get_supported_filesystems(self):
		return supported_filesystems['all'] + supported_filesystems[self._arch]

	##
	# Sets disk geometry info from disk. This function is used internally by __init__()
	def set_disk_geometry_from_disk(self):
		self._geometry = {
		  'sector_size': self._parted_dev.sector_size,
		  'total_bytes': self._parted_dev.length * self._parted_dev.sector_size,
		  'heads': self._parted_dev.heads,
		  'cylinders': self._parted_dev.cylinders,
		  'sectors': self._parted_dev.sectors,
		  'cylinder_bytes': self._parted_dev.heads * self._parted_dev.sectors * self._parted_dev.sector_size,
		  'total_sectors': self._parted_dev.length,
		  'sectors_in_cylinder': self._parted_dev.heads * self._parted_dev.sectors,
		  'total_mb': long((self._parted_dev.length * self._parted_dev.sector_size) / MEGABYTE)
		}

	##
	# Sets partition info from disk.
	def set_partitions_from_disk(self):
		self._partitions = []
		parted_part = self._parted_disk.next_partition()
		while parted_part:
			# Make sure it's a physical partition or unallocated space
			if parted_part.num >= 1 or parted_part.type_name == "free":
				self._partitions.append(Partition(self, parted_part))
			parted_part = self._parted_disk.next_partition(parted_part)

	##
	# Checks to see if partitions are mounted on device
	def has_mounted_partitions(self):
		if self._parted_dev.is_busy():
			return True
		return False

	##
	# Returns the partition object with the specified minor
	# @param idx Index of partition object
	def get_partition(self, idx):
		return self._partitions[idx]

	def get_partition_idx_from_part(self, part):
		for idx, tmppart in enumerate(self._partitions):
			if tmppart['start'] == part['start'] and tmppart['end'] == part['end']:
				return idx
		else:
			return -1

	def get_partition_idx_from_minor(self, minor):
		for idx, tmppart in enumerate(self._partitions):
			if tmppart['minor'] == minor:
				return idx
		else:
			return -1

	def get_partition_idx_from_start_end(self, start, end):
		for idx, tmppart in enumerate(self._partitions):
			if tmppart['start'] == start and tmppart['end'] == end:
				return idx
		else:
			return -1

	def get_partiton_at_start(self, start):
		for i, part in enumerate(self._partitions):
			if part['start'] == start:
				return i
		return -1

	##
	# Returns name of device (e.g. /dev/hda) being represented
	def get_device(self):
		return self._device

	##
	# Uses magic to apply the recommended partition layout
	def do_recommended(self):
		freeidx = -1
		free_part = None
		remaining_free = 0
		recommended_parts = [ { 'type': "ext2", 'size': 100, 'mountpoint': '/boot', 'mountopts': 'defaults' },
                              { 'type': "linux-swap", 'size': 512, 'mountpoint': 'swap', 'mountopts': 'defaults' },
                              { 'type': "ext3", 'size': "*", 'mountpoint': '/', 'mountopts': 'noatime' } ]
		localmounts = copy.deepcopy(self._install_profile.get_mounts())
		physical_memory = int(GLIUtility.spawn(r"free -m | egrep '^Mem:' | sed -e 's/^Mem: \+//' -e 's/ \+.\+$//'", return_output=True)[1].strip())
		self.clear_partitions()
		for newpart in recommended_parts:
			# Find idx of remaining unallocated space
			for idx, part in enumerate(self._partitions):
				# We want to ignore any "false" free space
				if part['type'] == "free" and part['mb'] >= 10:
					freeidx = idx
					free_part = part
					remaining_free = free_part['mb']
					break
			# Small hack to calculate optimal swap partition size
			if newpart['type'] == "linux-swap" and physical_memory:
				newpart['size'] = physical_memory * 2
				if newpart['size'] > 2048:
					newpart['size'] = 2048
			if newpart['size'] == "*":
				newpart['size'] = remaining_free
			newidx = self.add_partition(freeidx, newpart['size'], newpart['type'])
			for i, mount in enumerate(localmounts):
				if mount['devnode'] == self._partitions[newidx]['devnode']:
					del localmounts[i]
					break
			localmounts.append({ 'devnode': self._partitions[newidx]['devnode'], 'type': parted_type_map.get(newpart['type'], newpart['type']), 'mountpoint': newpart['mountpoint'], 'mountopts': newpart['mountopts'] })
		self._install_profile.set_mounts(localmounts)

	def _megabytes_to_sectors(self, mb, sector_bytes=512):
		return long(mb * MEGABYTE / sector_bytes)

	def _sectors_to_megabytes(self, sectors, sector_bytes=512):
		return float((float(sectors) * sector_bytes)/ float(MEGABYTE))

	##
	# Adds a new partition to the partition info
	# @param freeidx minor of unallocated space partition is being created in
	# @param mb size of partition in MB
	# @param type Partition type (ext2, ext3, fat32, linux-swap, free, extended, etc.)
	def add_partition(self, freeidx, mb, fs, mkfsopts="", pregap=0):
		types = { 'primary': parted.PARTITION_PRIMARY, 'extended': parted.PARTITION_EXTENDED, 'logical': parted.PARTITION_LOGICAL }
		fs_types = {}
		fstype = None
		try:
			free_part = self._partitions[freeidx]
		except:
			# raise an exception here
			pass
		if mb > free_part['mb']:
			# raise an exception here
			pass
		# Enumerate supported filesystem types
		fs_type = parted.file_system_type_get_next()
		while fs_type:
			fs_types[fs_type.name] = fs_type
			fs_type = parted.file_system_type_get_next(fs_type)
		# apple_bootstrap is a "magic" hfs
		if fs == "apple_bootstrap":
			fs = "hfs"
		# determine correct partition type
		parttype = "primary"
		if fs == "extended":
			fstype = None
			parttype = "extended"
		else:
			# grab relevant parted filesystemtype object
			if fs:
				fstype = fs_types[fs]
			if free_part.is_logical():
				parttype = "logical"
		# figure out start/end sectors
		start = free_part['start'] + self._megabytes_to_sectors(pregap)
		end = start + self._megabytes_to_sectors(mb)
		parted_newpart = self._parted_disk.partition_new(types[parttype], fstype, start, end)
		constraint = self._parted_disk.dev.constraint_any()
		self._parted_disk.add_partition(parted_newpart, constraint)
		self._parted_disk.commit()
		self.set_partitions_from_disk()
		if parttype != "extended":
			newpart = self._partitions[self.get_partition_idx_from_minor(parted_newpart.num)]
			devnode = newpart['devnode']
			format_cmds = { 'linux-swap': "mkswap", 'fat16': "mkfs.vfat -F 16", 'fat32': "mkfs.vfat -F 32",
			                'ntfs': "mkntfs", 'xfs': "mkfs.xfs -f", 'jfs': "mkfs.jfs -f",
			                'reiserfs': "mkfs.reiserfs -f", 'ext2': "mkfs.ext2", 'ext3': "mkfs.ext3",
			                'hfs': "hformat", 'apple_bootstrap': "hformat"
			              }
			if fs in format_cmds:
				cmdname = format_cmds[fs]
			else:
				raise GLIException("PartitionFormatError", 'fatal', '_partition_format_step', "Unknown partition type " + fstype)
			# sleep a bit first
			time.sleep(1)
			wait_for_device_node(devnode)
			cmd = "%s %s %s" % (cmdname, mkfsopts, devnode)
			ret = GLIUtility.spawn(cmd)
			if not GLIUtility.exitsuccess(ret):
				raise GLIException("PartitionFormatError", 'fatal', '_partition_format_step', "Could not create %s filesystem on %s" % (fstype, devnode))
		self.set_partitions_from_disk()
		newidx = self.get_partition_idx_from_start_end(parted_newpart.geom.start, parted_newpart.geom.end)
		return newidx

	##
	# Removes partition from partition info
	# @param minor Minor of partition to remove
	def remove_partition(self, partidx):
		try:
			tmp_part = self._partitions[partidx]
		except:
			# raise exception here
			pass
		if tmp_part['minor'] < 1:
			# raise an exception here
			pass
		try:
			self._parted_disk.delete_partition(self._parted_disk.get_partition(tmp_part['minor']))
		except:
			# raise an exception here
			pass
		self._parted_disk.commit()
		self.set_partitions_from_disk()

#	def resize_partition(self, partidx, mb):
#		part = self._partitions[partidx]
#		type = part['type']
#		start = part['start']
#		end = start + long(mb * MEGABYTE / 512) - 1
#
#		total_sectors = end - start + 1
#		total_bytes = long(total_sectors) * 512
#
#		# Delete partition and recreate at same start point with new size if growing
#		if mb > part['mb']:
#			curminor = self._find_current_minor_for_part(device, start)
#			self._parted_disk.delete_partition(self._parted_disk.get_partition(part['minor']))
#			if part['logical']:
#				tmptype = "logical"
#			else:
#				tmptype = "primary"
#			self._add_partition(parted_disk, start, end, tmptype, tmppart_new['type'], strict_start=True)
#			parted_disk.commit()
#
#			curminor = self._find_current_minor_for_part(device, start)
#			devnode = device + str(curminor)
#
#			wait_for_device_node(devnode)
#
#			if type in ("ext2", "ext3"):
#				resizecmd = "resize2fs %s %sK" % (devnode, str(int((total_bytes - (2 * MEGABYTE)) / 1024)))
#				self._logger.log("_partition_resize_step(): running: " + resizecmd)
#				ret = GLIUtility.spawn(resizecmd, logfile=self._compile_logfile, append_log=True)
#				if not GLIUtility.exitsuccess(ret):
#					raise GLIException("PartitionResizeError", 'fatal', 'partition', "could not resize ext2/3 filesystem on " + devnode)
#			elif type == "ntfs":
#				ret = GLIUtility.spawn("yes | ntfsresize -v --size " + str(total_bytes) + " " + devnode, logfile=self._compile_logfile, append_log=True)
#				if not GLIUtility.exitsuccess(ret):
#					raise GLIException("PartitionResizeError", 'fatal', 'partition', "could not resize NTFS filesystem on " + devnode)
#			elif type in ("linux-swap", "fat32", "fat16"):
#				parted_fs = parted_disk.get_partition(curminor).geom.file_system_open()
#				resize_constraint = parted_fs.get_resize_constraint()
#				if total_sectors < resize_constraint.min_size or start != resize_constraint.start_range.start:
#					raise GLIException("PartitionError", 'fatal', 'partition', "New size specified for " + devnode + " is not within allowed boundaries (blame parted)")
#				new_geom = resize_constraint.start_range.duplicate()
#				new_geom.set_start(start)
#				new_geom.set_end(end)
#				try:
#					parted_fs.resize(new_geom)
#				except:
#					raise GLIException("PartitionResizeError", 'fatal', 'partition', "could not resize " + devnode)
#			self._logger.log("  Deleting old minor " + str(oldpart) + " to be recreated in next pass")
#			self._delete_partition(parted_disk, oldpart)
#		parted_disk.delete_all()
#		parted_disk.commit()


	##
	# This function clears the partition table
	def clear_partitions(self, disklabel=None):
		if not disklabel:
			disklabel = archinfo[self._arch]
		self._parted_disk = self._parted_dev.disk_new_fresh(parted.disk_type_get(disklabel))
		self._disklabel = disklabel
		self._parted_disk.commit()
		self.set_partitions_from_disk()

	##
	# Returns an ordered list (disk order) of partitions
	def get_partitions(self):
		return self._partitions

	##
	# Returns the minor of the extended partition, if any
	def get_extended_partition(self):
		for idx, part in enumerate(self._partitions):
			if part.is_extended():
				return idx
		return -1

	##
	# Returns the drive model
	def get_model(self):
		return self._parted_dev.model

	##
	# Returns the disklabel type
	def get_disklabel(self):
		return self._disklabel

	##
	# Returns all the geometry information
	def get_geometry(self):
		return self._geometry

##
# This class represents a partition within a GLIStorageDevice object
class Partition:
	"Class representing a single partition within a Device object"

	##
	# Initialization function for the Partition class
	# @param device Parent GLIStorageDevice object
	# @param parted_part parted.Partition object
	def __init__(self, device, parted_part):
		self._device = device
		self._start = parted_part.geom.start
		self._end = parted_part.geom.end
		self._type = parted_part.type_name
		self._minor = parted_part.num
		self._mb = int((self._end - self._start + 1) * device._geometry['sector_size'] / MEGABYTE) - 1
		self._part_name = ""
		self._resizeable = False

		# determine the /dev node that refers to this partition
		tmpdevice = device.get_device()
		label_type = device._parted_disk.type.name
		if label_type == "loop":
			self._devnode = tmpdevice
		elif tmpdevice[-1] in "0123456789":
			self._devnode = tmpdevice + "p" + str(self._minor)
		else:
			self._devnode = tmpdevice + str(self._minor)

		if not self._type == "free":
			if parted_part.fs_type:
				self._type = parted_part.fs_type.name
				if self._type == "hfs" and parted_part.is_flag_available(1) and parted_part.get_flag(1):
					self._type = "apple_bootstrap"
			else:
				# Add additional partition identification code here
				self._type = "unknown"
			if parted_part.type == 2: self._type = "extended"
			if device._parted_disk.type.check_feature(parted.DISK_TYPE_PARTITION_NAME):
				self._part_name = parted_part.get_name()
			# The 10 is completely arbitrary. If flags seem to be missed, this number should be increased
#			for flag in range(0, 10):
#				if parted_part.is_flag_available(flag) and parted_part.get_flag(flag):
#					self._flags.append(flag)

		if type == "ext2" or type == "ext3":
			block_size = long(string.strip(commands.getoutput("dumpe2fs -h " + self._devnode + r" 2>&1 | grep -e '^Block size:' | sed -e 's/^Block size:\s\+//'")))
			free_blocks = long(string.strip(commands.getoutput("dumpe2fs -h " + self._devnode + r" 2>&1 | grep -e '^Free blocks:' | sed -e 's/^Free blocks:\s\+//'")))
			free_bytes = long(block_size * free_blocks)
			# can't hurt to pad (the +50) it a bit since this is really just a guess
			self._min_size = self._mb - long(free_bytes / MEGABYTE) + 50
			self._resizeable = True
		elif type == "ntfs":
			min_bytes = long(commands.getoutput("ntfsresize -f --info " + self._devnode + " | grep -e '^You might resize' | sed -e 's/You might resize at //' -e 's/ bytes or .\+//'"))
			self._min_size = long(min_bytes / MEGABYTE) + 50
			self._resizeable = True
		else:
			try:
				parted_fs = parted_part.geom.file_system_open()
				resize_constraint = parted_fs.get_resize_constraint()
				min_bytes = resize_constraint.min_size * self._device._geometry['sector_size']
				self._min_size = long(min_bytes / MEGABYTE) + 1
				self._resizeable = True
			except:
				self._min_size = self._mb
				self._resizeable = False

	def __getitem__(self, name):
		tmpdict = {
		  'start': self.get_start,
		  'end': self.get_end,
		  'type': self.get_type,
		  'minor': self.get_minor,
		  'mb': self.get_mb,
#		  'flags': self.get_flags,
		  'name': self.get_name,
		  'devnode': self.get_devnode,
		  'resizeable': self.get_resizeable,
		  'min_size': self.get_min_size,
		  'max_size': self.get_max_size,
		  'extended': self.is_extended,
		  'logical': self.is_logical,
		  'device': self.get_device
		}
		if name in tmpdict:
			return tmpdict[name]()
		else:
			raise ValueError(name + " is not a valid attribute!")

	def __setitem__(self, name, value):
		tmpdict = {
#		  'flags': self.set_flags,
		  'name': self.set_name
		}
		if name in tmpdict:
			tmpdict[name](value)
		else:
			raise ValueError(name + " is not a valid attribute!")

	##
	# Returns the dev node that this partition will have
	def get_devnode(self):
		return self._devnode

	##
	# Returns whether or not the partition is extended
	def is_extended(self):
		if self._type == "extended":
			return True
		else:
			return False

	##
	# Returns whether or not the partition is logical
	def is_logical(self):
		if self._type == "free":
			ext_idx = self._device.get_extended_partition()
			if ext_idx == -1: return False
			ext_part = self._device[ext_idx]
			if self._start >= ext_part['start'] and self._start <= ext_part['end'] and self._end >= ext_part['start'] and self._end <= ext_part['end']:
				return True
			else:
				return False
		elif self._device._labelinfo['extended'] and self._minor > 4:
			return True
		else:
			return False

	##
	# Returns a list of logical partitions if this is an extended partition
	def get_logicals(self):
		if not self.is_extended():
			return None
		logicals = []
		for part in self._device._partitions:
			if part.is_logical():
				logicals.append(part)
		return logicals

	##
	# Returns the start sector for the partition
	def get_start(self):
		return long(self._start)

	##
	# Returns end sector for the partition
	def get_end(self):
		return long(self._end)

	##
	# Returns size of partition in MB
	def get_mb(self):
		return self._mb

	##
	# Returns type of partition
	def get_type(self):
		return self._type

	##
	# Returns parent Device object
	def get_device(self):
		return self._device

	##
	# Returns minor of partition
	def get_minor(self):
		return self._minor

	##
	# Returns whether the partition is resizeable
	def get_resizeable(self):
		return self._resizeable

	##
	# Sets partition flags
	def set_flags(self, flags):
		self._flags = flags

	##
	# Returns partition flags
	def get_flags(self):
		return self._flags

	##
	# Sets partition name
	def set_name(self, name):
		self._name = name

	##
	# Returns partition name
	def get_name(self):
		return self._name

	##
	# Returns minimum MB for resize
	def get_min_size(self):
		if self._resizeable:
			return self._min_size
		elif self._type == "free":
			return 0
		else:
			return self._mb

	##
	# Returns maximum MB for resize
	def get_max_size(self):
		if self._resizeable:
			partidx = self._device.get_partition_idx_from_minor(self._minor)
			next_part = self._device._partitions[partidx + 1]
			if next_part['type'] == "free":
				if (next_part.is_logical() and self.is_logical()) or (not next_part.is_logical() and not self.is_logical()):
					return self._mb + next_part['mb']
				else:
					return self._mb
			else:
				return self._mb
		else:
			return self._mb

"""
	##
	# Resizes the partition
	# @param mb New size in MB
	def resize(self, mb):
		minor_pos = self._device.get_partition_idx_from_minor(self._minor)
		try:
			free_minor = self._device._partitions[minor_pos+1].get_minor()
		except:
			free_minor = 0
		if mb < self._mb:
			# Shrinking
			if not free_minor or not self._device.get_partition(free_minor).get_type() == "free":
				if self._device._disklabel == "mac":
					free_minor = self._minor + 1
				elif self.is_logical():
					free_minor = self._minor + FREE_MINOR_FRAC_LOG
				else:
					free_minor = self._minor + FREE_MINOR_FRAC_PRI
				if self._device.get_partition(free_minor):
					for i, part in enumerate(self._device._partitions):
						if i <= minor_pos or free_minor > part.get_minor(): continue
						part.set_minor(part.get_minor() + 1)
				self._device._partitions.insert(minor_pos+1, Partition(self._device, free_minor, self._mb - mb, 0, 0, "free", format=False, existing=False))
			else:
				self._device.get_partition(free_minor).set_mb(self._device.get_partition(free_minor).get_mb() + (self._mb - mb))
			self._mb = mb
		else:
			if mb == self._mb + self._device.get_partition(free_minor).get_mb():
				# Using all available unallocated space
				self._device._partitions.pop(self._device.get_partition_idx_from_minor(free_minor))
				self._mb = mb
			else:
				# Growing
				self._device.get_partition(free_minor).set_mb(self._device.get_partition(free_minor).get_mb() - (mb - self._mb))
				self._mb = mb
		self._resized = True
		self._device.tidy_partitions()
"""

##
# Returns a list of detected partitionable devices
def detect_devices():
	devices = []
	
	# Make sure sysfs exists
	# TODO: rewrite for 2.4 support
	if not os.path.exists("/sys/bus"):
		raise GLIException("GLIStorageDeviceError", 'fatal', 'detect_devices', "no sysfs found (you MUST use a kernel >2.6)")
	# Make sure /proc/partitions exists
	if not os.path.exists("/proc/partitions"):
		raise GLIException("GLIStorageDeviceError", 'fatal', 'detect_devices', "/proc/partitions does not exist! Please make sure procfs is in your kernel and mounted!")
	
	# Load /proc/partitions into the variable 'partitions'
	partitions = []
	for line in open("/proc/partitions"):
		tmpparts = line.split()
		if len(tmpparts) < 4 or not tmpparts[0].isdigit() or not tmpparts[1].isdigit():
			continue
		
		# Get the major, minor and device name
		major = int(tmpparts[0])
		minor = int(tmpparts[1])
		device = "/dev/" + tmpparts[3]
		
		# If there is no /dev/'device_name', then scan
		# all the devices in /dev to try and find a
		# devices with the same major and minor		
		if not os.path.exists(device):
			device = None
			for path, dirs, files in os.walk("/dev"):
				for d_file in files:
					full_file = os.path.join(path, d_file)
					if not os.path.exists(full_file):
						continue
					statres = os.stat(full_file)
					fmaj = os.major(statres.st_rdev)
					fmin = os.minor(statres.st_rdev)
					if fmaj == major and fmin == minor:
						device = full_file
						break
			if not device:
				continue
			
		partitions.append(( major, minor, device ))
	
	# Scan sysfs for the devices of type 'x'
	# 'x' being a member of the list below:
	# Compaq cards.../sys/block/{cciss,ida}!cXdX/dev
	for dev_glob in ("/sys/bus/ide/devices/*/block*/dev", "/sys/bus/scsi/devices/*/block*/dev", "/sys/block/cciss*/dev", "/sys/block/ida*/dev"):
		sysfs_devices = glob(dev_glob)
		if not sysfs_devices: continue
		for sysfs_device in sysfs_devices:
			# Get the major and minor info
			try:
				major, minor = open(sysfs_device).read().split(":")
				major = int(major)
				minor = int(minor)
			except:
				raise GLIException("GLIStorageDeviceError", 'fatal', 'detect_devices', "invalid major/minor in " + sysfs_device)
			
			# Find a device listed in /proc/partitions
			# that has the same minor and major as our
			# current block device.
			for record in partitions:
				if major == record[0] and minor == record[1]:
					devices.append(record[2])

	# We have assembled the list of devices, so return it
	return devices

def list_partitions():
	# Load /proc/partitions into the variable 'partitions'
#	return [("/dev/" + x[3]) for x in [y.strip().split() for y in open("/proc/partitions", "r").readlines()] if len(x) >= 4 and x[3][-1].isdigit()]
	partitions = {}
	for line in open("/proc/partitions"):
		tmpparts = line.split()
		if len(tmpparts) < 4 or not tmpparts[0].isdigit() or not tmpparts[1].isdigit():
			continue
		device = "/dev/" + tmpparts[3]
		if device == "/dev/loop0":  #we don't want this.
			continue   
		if not device[-1].isdigit():  #A Drive
			continue
		else:
			partitions[device] = tmpparts[2]
	return partitions

def wait_for_device_node(devnode):
	if GLIUtility.is_file("/sbin/udevsettle"):
		GLIUtility.spawn("/sbin/udevsettle")
		if not GLIUtility.is_file(devnode):
			GLIUtility.spawn("/sbin/udevsettle")
	else:
		for i in range(0, 10):
			if GLIUtility.is_file(devnode):
				break
			time.sleep(1)
		time.sleep(1)
		for i in range(0, 10):
			if GLIUtility.is_file(devnode):
				break
			time.sleep(1)