path: root/storage/partitioning.py

# partitioning.py
# Disk partitioning functions.
#
# Copyright (C) 2009  Red Hat, Inc.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# the GNU General Public License v.2, or (at your option) any later version.
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY expressed or implied, including the implied warranties of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
# Public License for more details.  You should have received a copy of the
# GNU General Public License along with this program; if not, write to the
# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.  Any Red Hat trademarks that are incorporated in the
# source code or documentation are not subject to the GNU General Public
# License and may only be used or replicated with the express permission of
# Red Hat, Inc.
#
# Red Hat Author(s): Dave Lehman <dlehman@redhat.com>
#

import sys
import os
from operator import add, sub, gt, lt

import parted
from pykickstart.constants import *

from constants import *

from errors import *
from deviceaction import *
from devices import PartitionDevice, LUKSDevice, devicePathToName
from formats import getFormat

import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)

import logging
log = logging.getLogger("storage")

def _createFreeSpacePartitions(anaconda):
    # get a list of disks that have at least one free space region of at
    # least 100MB
    disks = []
    for disk in anaconda.storage.partitioned:
        if anaconda.storage.clearPartDisks and \
           (disk.name not in anaconda.storage.clearPartDisks):
            continue

        part = disk.format.firstPartition
        while part:
            if not part.type & parted.PARTITION_FREESPACE:
                part = part.nextPartition()
                continue

            if part.getSize(unit="MB") > 100:
                disks.append(disk)
                break

            part = part.nextPartition()

    # create a separate pv partition for each disk with free space
    devs = []
    for disk in disks:
        if anaconda.storage.encryptedAutoPart:
            fmt_type = "luks"
            fmt_args = {"escrow_cert": anaconda.storage.autoPartEscrowCert,
                        "add_backup_passphrase": anaconda.storage.autoPartAddBackupPassphrase}
        else:
            fmt_type = "lvmpv"
            fmt_args = {}
        part = anaconda.storage.newPartition(fmt_type=fmt_type,
                                                fmt_args=fmt_args,
                                                size=1,
                                                grow=True,
                                                disks=[disk])
        anaconda.storage.createDevice(part)
        devs.append(part)

    return (disks, devs)

def _schedulePartitions(anaconda, disks):
    #
    # Convert storage.autoPartitionRequests into Device instances and
    # schedule them for creation
    #
    # First pass is for partitions only. We'll do LVs later.
    #
    for request in anaconda.storage.autoPartitionRequests:
        if request.asVol:
            continue

        if request.fstype is None:
            request.fstype = anaconda.storage.defaultFSType
        # This is a little unfortunate but let the backend dictate the rootfstype
        # so that things like live installs can do the right thing
        if request.mountpoint == "/" and anaconda.backend.rootFsType != None:
            request.fstype = anaconda.backend.rootFsType

        dev = anaconda.storage.newPartition(fmt_type=request.fstype,
                                            size=request.size,
                                            grow=request.grow,
                                            maxsize=request.maxSize,
                                            mountpoint=request.mountpoint,
                                            disks=disks,
                                            weight=request.weight)

        # schedule the device for creation
        anaconda.storage.createDevice(dev)

    # make sure preexisting broken lvm/raid configs get out of the way
    return

def _scheduleLVs(anaconda, devs):
    if anaconda.storage.encryptedAutoPart:
        pvs = []
        for dev in devs:
            pv = LUKSDevice("luks-%s" % dev.name,
                            format=getFormat("lvmpv", device=dev.path),
                            size=dev.size,
                            parents=dev)
            pvs.append(pv)
            anaconda.storage.createDevice(pv)
    else:
        pvs = devs

    # create a vg containing all of the autopart pvs
    vg = anaconda.storage.newVG(pvs=pvs)
    anaconda.storage.createDevice(vg)

    initialVGSize = vg.size

    #
    # Convert storage.autoPartitionRequests into Device instances and
    # schedule them for creation.
    #
    # Second pass, for LVs only.
    for request in anaconda.storage.autoPartitionRequests:
        if not request.asVol:
            continue

        if request.requiredSpace and request.requiredSpace > initialVGSize:
            continue

        if request.fstype is None:
            request.fstype = anaconda.storage.defaultFSType

        # This is a little unfortunate but let the backend dictate the rootfstype
        # so that things like live installs can do the right thing
        if request.mountpoint == "/" and anaconda.backend.rootFsType != None:
            request.fstype = anaconda.backend.rootFsType

        # FIXME: move this to a function and handle exceptions
        dev = anaconda.storage.newLV(vg=vg,
                                     fmt_type=request.fstype,
                                     mountpoint=request.mountpoint,
                                     grow=request.grow,
                                     maxsize=request.maxSize,
                                     size=request.size)

        # schedule the device for creation
        anaconda.storage.createDevice(dev)


def doAutoPartition(anaconda):
    log.debug("doAutoPartition(%s)" % anaconda)
    log.debug("doAutoPart: %s" % anaconda.storage.doAutoPart)
    log.debug("clearPartType: %s" % anaconda.storage.clearPartType)
    log.debug("clearPartDisks: %s" % anaconda.storage.clearPartDisks)
    log.debug("autoPartitionRequests: %s" % anaconda.storage.autoPartitionRequests)
    log.debug("storage.disks: %s" % [d.name for d in anaconda.storage.disks])
    log.debug("storage.partitioned: %s" % [d.name for d in anaconda.storage.partitioned])
    log.debug("all names: %s" % [d.name for d in anaconda.storage.devices])
    if anaconda.dir == DISPATCH_BACK:
        anaconda.storage.reset()
        return

    disks = []
    devs = []

    if anaconda.storage.doAutoPart:
        clearPartitions(anaconda.storage)

    if anaconda.storage.doAutoPart:
        (disks, devs) = _createFreeSpacePartitions(anaconda)

        if disks == []:
            if anaconda.ksdata:
                msg = _("Could not find enough free space for automatic "
                        "partitioning.  Press 'OK' to exit the installer.")
            else:
                msg = _("Could not find enough free space for automatic "
                        "partitioning, please use another partitioning method.")

            anaconda.intf.messageWindow(_("Error Partitioning"), msg,
                                        custom_icon='error')

            if anaconda.ksdata:
                sys.exit(0)

            anaconda.storage.reset()
            return DISPATCH_BACK

        _schedulePartitions(anaconda, disks)

    # sanity check the individual devices
    log.warning("not sanity checking devices because I don't know how yet")

    # run the autopart function to allocate and grow partitions
    try:
        doPartitioning(anaconda.storage,
                       exclusiveDisks=anaconda.storage.clearPartDisks)

        if anaconda.storage.doAutoPart:
            _scheduleLVs(anaconda, devs)

        # grow LVs
        growLVM(anaconda.storage)
    except PartitioningWarning as msg:
        if not anaconda.ksdata:
            anaconda.intf.messageWindow(_("Warnings During Automatic "
                                          "Partitioning"),
                           _("Following warnings occurred during automatic "
                           "partitioning:\n\n%s") % (msg,),
                           custom_icon='warning')
        else:
            log.warning(msg)
    except PartitioningError as msg:
        # restore drives to original state
        anaconda.storage.reset()
        if not anaconda.ksdata:
            extra = ""

            if anaconda.displayMode != "t":
                anaconda.dispatch.skipStep("partition", skip = 0)
        else:
            extra = _("\n\nPress 'OK' to exit the installer.")
        anaconda.intf.messageWindow(_("Error Partitioning"),
               _("Could not allocate requested partitions: \n\n"
                 "%(msg)s.%(extra)s") % {'msg': msg, 'extra': extra},
               custom_icon='error')

        if anaconda.ksdata:
            sys.exit(0)
        else:
            return

    # sanity check the collection of devices
    log.warning("not sanity checking storage config because I don't know how yet")
    # now do a full check of the requests
    (errors, warnings) = anaconda.storage.sanityCheck()
    if warnings:
        for warning in warnings:
            log.warning(warning)
    if errors:
        errortxt = "\n".join(errors)
        if anaconda.ksdata:
            extra = _("\n\nPress 'OK' to exit the installer.")
        else:
            extra = _("\n\nPress 'OK' to choose a different partitioning option.")

        anaconda.intf.messageWindow(_("Automatic Partitioning Errors"),
                           _("The following errors occurred with your "
                             "partitioning:\n\n%(errortxt)s\n\n"
                             "This can happen if there is not enough "
                             "space on your hard drive(s) for the "
                             "installation. %(extra)s")
                           % {'errortxt': errortxt, 'extra': extra},
                           custom_icon='error')
        #
        # XXX if in kickstart we reboot
        #
        if anaconda.ksdata:
            anaconda.intf.messageWindow(_("Unrecoverable Error"),
                               _("The system will now reboot."))
            sys.exit(0)
        anaconda.storage.reset()
        return DISPATCH_BACK

def shouldClear(device, clearPartType, clearPartDisks=None):
    if clearPartType not in [CLEARPART_TYPE_LINUX, CLEARPART_TYPE_ALL]:
        return False

    if isinstance(device, PartitionDevice):
        # Never clear the special first partition on a Mac disk label, as that
        # holds the partition table itself.
        if device.disk.format.partedDisk.type == "mac" and \
           device.partedPartition.number == 1 and \
           device.partedPartition.name == "Apple":
            return False

        # If we got a list of disks to clear, make sure this one's on it
        if clearPartDisks and device.disk.name not in clearPartDisks:
            return False

        # We don't want to fool with extended partitions, freespace, &c
        if device.partType not in [parted.PARTITION_NORMAL,
                                   parted.PARTITION_LOGICAL]:
            return False

        if clearPartType == CLEARPART_TYPE_LINUX and \
           not device.format.linuxNative and \
           not device.getFlag(parted.PARTITION_LVM) and \
           not device.getFlag(parted.PARTITION_RAID) and \
           not device.getFlag(parted.PARTITION_SWAP):
            return False
    elif device.isDisk and not device.partitioned:
        # If we got a list of disks to clear, make sure this one's on it
        if clearPartDisks and device.name not in clearPartDisks:
            return False

        if clearPartType == CLEARPART_TYPE_LINUX and \
           not device.format.linuxNative:
            return False

    # Don't clear devices holding install media.
    if device.protected:
        return False

    # TODO: do platform-specific checks on ia64, pSeries, iSeries, mac

    return True

def clearPartitions(storage):
    """ Clear partitions and dependent devices from disks.

        Arguments:

            storage -- a storage.Storage instance

        Keyword arguments:

            None

        NOTES:

            - Needs some error handling, especially for the parted bits.

    """
    if storage.clearPartType is None or storage.clearPartType == CLEARPART_TYPE_NONE:
        # not much to do
        return

    # we are only interested in partitions that physically exist
    partitions = [p for p in storage.partitions if p.exists]
    # Sort partitions by descending partition number to minimize confusing
    # things like multiple "destroy sda5" actions due to parted renumbering
    # partitions. This can still happen through the UI but it makes sense to
    # avoid it where possible.
    partitions.sort(key=lambda p: p.partedPartition.number, reverse=True)
    for part in partitions:
        log.debug("clearpart: looking at %s" % part.name)
        if not shouldClear(part, storage.clearPartType, storage.clearPartDisks):
            continue

        log.debug("clearing %s" % part.name)

        # XXX is there any argument for not removing incomplete devices?
        #       -- maybe some RAID devices
        devices = storage.deviceDeps(part)
        while devices:
            log.debug("devices to remove: %s" % ([d.name for d in devices],))
            leaves = [d for d in devices if d.isleaf]
            log.debug("leaves to remove: %s" % ([d.name for d in leaves],))
            for leaf in leaves:
                storage.destroyDevice(leaf)
                devices.remove(leaf)

        log.debug("partitions: %s" % [p.getDeviceNodeName() for p in part.partedPartition.disk.partitions])
        storage.destroyDevice(part)

    # now remove any empty extended partitions
    removeEmptyExtendedPartitions(storage)

def removeEmptyExtendedPartitions(storage):
    for disk in storage.partitioned:
        log.debug("checking whether disk %s has an empty extended" % disk.name)
        extended = disk.format.extendedPartition
        logical_parts = disk.format.logicalPartitions
        log.debug("extended is %s ; logicals is %s" % (extended, [p.getDeviceNodeName() for p in logical_parts]))
        if extended and not logical_parts:
            log.debug("removing empty extended partition from %s" % disk.name)
            extended_name = devicePathToName(extended.getDeviceNodeName())
            extended = storage.devicetree.getDeviceByName(extended_name)
            storage.destroyDevice(extended)
            #disk.partedDisk.removePartition(extended.partedPartition)

    for disk in [d for d in storage.disks if d not in storage.partitioned]:
        # clear any whole-disk formats that need clearing
        if shouldClear(disk, storage.clearPartType, storage.clearPartDisks):
            log.debug("clearing %s" % disk.name)
            devices = storage.deviceDeps(disk)
            while devices:
                log.debug("devices to remove: %s" % ([d.name for d in devices],))
                leaves = [d for d in devices if d.isleaf]
                log.debug("leaves to remove: %s" % ([d.name for d in leaves],))
                for leaf in leaves:
                    storage.destroyDevice(leaf)
                    devices.remove(leaf)

            destroy_action = ActionDestroyFormat(disk)
            newLabel = getFormat("disklabel", device=disk.path)
            create_action = ActionCreateFormat(disk, format=newLabel)
            storage.devicetree.registerAction(destroy_action)
            storage.devicetree.registerAction(create_action)

def partitionCompare(part1, part2):
    """ More specifically defined partitions come first.

        < 1 => x < y
          0 => x == y
        > 1 => x > y
    """
    ret = 0

    if part1.req_base_weight:
        ret -= part1.req_base_weight

    if part2.req_base_weight:
        ret += part2.req_base_weight

    # bootable partitions to the front
    ret -= cmp(part1.req_bootable, part2.req_bootable) * 1000

    # more specific disk specs to the front of the list
    # req_disks being empty is equivalent to it being an infinitely long list
    if part1.req_disks and not part2.req_disks:
        ret -= 500
    elif not part1.req_disks and part2.req_disks:
        ret += 500
    else:
        ret += cmp(len(part1.req_disks), len(part2.req_disks)) * 500

    # primary-only to the front of the list
    ret -= cmp(part1.req_primary, part2.req_primary) * 200

    # fixed size requests to the front
    ret += cmp(part1.req_grow, part2.req_grow) * 100

    # larger requests go to the front of the list
    ret -= cmp(part1.req_base_size, part2.req_base_size) * 50

    # potentially larger growable requests go to the front
    if part1.req_grow and part2.req_grow:
        if not part1.req_max_size and part2.req_max_size:
            ret -= 25
        elif part1.req_max_size and not part2.req_max_size:
            ret += 25
        else:
            ret -= cmp(part1.req_max_size, part2.req_max_size) * 25

    # give a little bump based on mountpoint
    if hasattr(part1.format, "mountpoint") and \
       hasattr(part2.format, "mountpoint"):
        ret += cmp(part1.format.mountpoint, part2.format.mountpoint) * 10

    if ret > 0:
        ret = 1
    elif ret < 0:
        ret = -1

    return ret

def getNextPartitionType(disk, no_primary=None):
    """ Find the type of partition to create next on a disk.

        Return a parted partition type value representing the type of the
        next partition we will create on this disk.

        If there is only one free primary partition and we can create an
        extended partition, we do that.

        If there are free primary slots and an extended partition we will
        recommend creating a primary partition. This can be overridden
        with the keyword argument no_primary.

        Arguments:

            disk -- a parted.Disk instance representing the disk

        Keyword arguments:

            no_primary -- given a choice between primary and logical
                          partitions, prefer logical

    """
    part_type = None
    extended = disk.getExtendedPartition()
    supports_extended = disk.supportsFeature(parted.DISK_TYPE_EXTENDED)
    logical_count = len(disk.getLogicalPartitions())
    max_logicals = disk.getMaxLogicalPartitions()
    primary_count = disk.primaryPartitionCount

    if primary_count < disk.maxPrimaryPartitionCount:
        if primary_count == disk.maxPrimaryPartitionCount - 1:
            # can we make an extended partition? now's our chance.
            if not extended and supports_extended:
                part_type = parted.PARTITION_EXTENDED
            elif not extended:
                # extended partitions not supported. primary or nothing.
                if not no_primary:
                    part_type = parted.PARTITION_NORMAL
            else:
                # there is an extended and a free primary
                if not no_primary:
                    part_type = parted.PARTITION_NORMAL
                elif logical_count < max_logicals:
                    # we have an extended with logical slots, so use one.
                    part_type = parted.PARTITION_LOGICAL
        else:
            # there are two or more primary slots left. use one unless we're
            # not supposed to make primaries.
            if not no_primary:
                part_type = parted.PARTITION_NORMAL
            elif extended and logical_count < max_logicals:
                part_type = parted.PARTITION_LOGICAL
    elif extended and logical_count < max_logicals:
        part_type = parted.PARTITION_LOGICAL

    return part_type

def getBestFreeSpaceRegion(disk, part_type, req_size,
                           boot=None, best_free=None, grow=None):
    """ Return the "best" free region on the specified disk.

        For non-boot partitions, we return the largest free region on the
        disk. For boot partitions, we return the first region that is
        large enough to hold the partition.

        Partition type (parted's PARTITION_NORMAL, PARTITION_LOGICAL) is
        taken into account when locating a suitable free region.

        For locating the best region from among several disks, the keyword
        argument best_free allows the specification of a current "best"
        free region with which to compare the best from this disk. The
        overall best region is returned.

        Arguments:

            disk -- the disk (a parted.Disk instance)
            part_type -- the type of partition we want to allocate
                         (one of parted's partition type constants)
            req_size -- the requested size of the partition (in MB)

        Keyword arguments:

            boot -- indicates whether this will be a bootable partition
                    (boolean)
            best_free -- current best free region for this partition
            grow -- indicates whether this is a growable request

    """
    log.debug("getBestFreeSpaceRegion: disk=%s part_type=%d req_size=%dMB "
              "boot=%s best=%s grow=%s" %
              (disk.device.path, part_type, req_size, boot, best_free, grow))
    extended = disk.getExtendedPartition()

    for _range in disk.getFreeSpaceRegions():
        if extended:
            # find out if there is any overlap between this region and the
            # extended partition
            log.debug("looking for intersection between extended (%d-%d) and free (%d-%d)" %
                    (extended.geometry.start, extended.geometry.end, _range.start, _range.end))

            # parted.Geometry.overlapsWith can handle this
            try:
                free_geom = extended.geometry.intersect(_range)
            except ArithmeticError, e:
                # this freespace region does not lie within the extended
                # partition's geometry
                free_geom = None

            if (free_geom and part_type == parted.PARTITION_NORMAL) or \
               (not free_geom and part_type == parted.PARTITION_LOGICAL):
                log.debug("free region not suitable for request")
                continue

            if part_type == parted.PARTITION_NORMAL:
                # we're allocating a primary and the region is not within
                # the extended, so we use the original region
                free_geom = _range
        else:
            free_geom = _range

        log.debug("current free range is %d-%d (%dMB)" % (free_geom.start,
                                                          free_geom.end,
                                                          free_geom.getSize()))
        free_size = free_geom.getSize()

        # For boot partitions, we want the first suitable region we find.
        # For growable or extended partitions, we want the largest possible
        # free region.
        # For all others, we want the smallest suitable free region.
        if grow or part_type == parted.PARTITION_EXTENDED:
            op = gt
        else:
            op = lt
        if req_size <= free_size:
            if not best_free or op(free_geom.length, best_free.length):
                best_free = free_geom

                if boot:
                    # if this is a bootable partition we want to
                    # use the first freespace region large enough
                    # to satisfy the request
                    break

    return best_free

def sectorsToSize(sectors, sectorSize):
    """ Convert length in sectors to size in MB.

        Arguments:

            sectors     -   sector count
            sectorSize  -   sector size for the device, in bytes
    """
    return (sectors * sectorSize) / (1024.0 * 1024.0)

def sizeToSectors(size, sectorSize):
    """ Convert size in MB to length in sectors.

        Arguments:

            size        -   size in MB
            sectorSize  -   sector size for the device, in bytes
    """
    return (size * 1024.0 * 1024.0) / sectorSize

def removeNewPartitions(disks, partitions):
    """ Remove newly added input partitions from input disks.

        Arguments:

            disks -- list of StorageDevice instances with DiskLabel format
            partitions -- list of PartitionDevice instances

    """
    log.debug("removing all non-preexisting partitions %s from disk(s) %s"
                % (["%s(id %d)" % (p.name, p.id) for p in partitions
                                                    if not p.exists],
                   [d.name for d in disks]))
    for part in partitions:
        if part.partedPartition and part.disk in disks:
            if part.exists:
                # we're only removing partitions that don't physically exist
                continue

            if part.isExtended:
                # these get removed last
                continue

            part.disk.format.partedDisk.removePartition(part.partedPartition)
            part.partedPartition = None
            part.disk = None

    for disk in disks:
        # remove empty extended so it doesn't interfere
        extended = disk.format.extendedPartition
        if extended and not disk.format.logicalPartitions:
            log.debug("removing empty extended partition from %s" % disk.name)
            disk.format.partedDisk.removePartition(extended)

def addPartition(disklabel, free, part_type, size):
    """ Return new partition after adding it to the specified disk.

        Arguments:

            disklabel -- disklabel instance to add partition to
            free -- where to add the partition (parted.Geometry instance)
            part_type -- partition type (parted.PARTITION_* constant)
            size -- size (in MB) of the new partition

        The new partition will be aligned.

        Return value is a parted.Partition instance.

    """
    start = free.start
    if not disklabel.alignment.isAligned(free, start):
        start = disklabel.alignment.alignNearest(free, start)

    if part_type == parted.PARTITION_LOGICAL:
        # make room for logical partition's metadata
        start += disklabel.alignment.grainSize

    if start != free.start:
        log.debug("adjusted start sector from %d to %d" % (free.start, start))

    if part_type == parted.PARTITION_EXTENDED:
        end = free.end
        length = end - start + 1
    else:
        # size is in MB
        length = sizeToSectors(size, disklabel.partedDevice.sectorSize)
        end = start + length - 1

    if not disklabel.endAlignment.isAligned(free, end):
        end = disklabel.endAlignment.alignNearest(free, end)
        log.debug("adjusted length from %d to %d" % (length, end - start + 1))

    new_geom = parted.Geometry(device=disklabel.partedDevice,
                               start=start,
                               end=end)

    max_length = disklabel.partedDisk.maxPartitionLength
    if max_length and new_geom.length > max_length:
        raise PartitioningError("requested size exceeds maximum allowed")

    # create the partition and add it to the disk
    partition = parted.Partition(disk=disklabel.partedDisk,
                                 type=part_type,
                                 geometry=new_geom)
    constraint = parted.Constraint(exactGeom=new_geom)
    disklabel.partedDisk.addPartition(partition=partition,
                                      constraint=constraint)
    return partition

def getFreeRegions(disks):
    """ Return a list of free regions on the specified disks.

        Arguments:

            disks -- list of parted.Disk instances

        Return value is a list of unaligned parted.Geometry instances.

    """
    free = []
    for disk in disks:
        for f in disk.format.partedDisk.getFreeSpaceRegions():
            if f.length > 0:
                free.append(f)

    return free

def doPartitioning(storage, exclusiveDisks=None):
    """ Allocate and grow partitions.

        When this function returns without error, all PartitionDevice
        instances must have their parents set to the disk they are
        allocated on, and their partedPartition attribute set to the
        appropriate parted.Partition instance from their containing
        disk. All req_xxxx attributes must be unchanged.

        Arguments:

            storage - Main anaconda Storage instance

        Keyword arguments:

            exclusiveDisks -- list of names of disks to use

    """
    anaconda = storage.anaconda
    disks = storage.partitioned
    if exclusiveDisks:
        disks = [d for d in disks if d.name in exclusiveDisks]

    for disk in disks:
        disk.setup()

    partitions = storage.partitions[:]
    for part in storage.partitions:
        part.req_bootable = False

        if part.exists or \
           (storage.deviceImmutable(part) and part.partedPartition):
            # if the partition is preexisting or part of a complex device
            # then we shouldn't modify it
            partitions.remove(part)
            continue

        if not part.exists:
            # start over with flexible-size requests
            part.req_size = part.req_base_size

    # FIXME: isn't there a better place for this to happen?
    try:
        bootDev = anaconda.platform.bootDevice()
    except DeviceError:
        bootDev = None

    if bootDev:
        bootDev.req_bootable = True

    # turn off cylinder alignment
    for partedDisk in [d.format.partedDisk for d in disks]:
        if partedDisk.isFlagAvailable(parted.DISK_CYLINDER_ALIGNMENT):
            partedDisk.unsetFlag(parted.DISK_CYLINDER_ALIGNMENT)

    removeNewPartitions(disks, partitions)
    free = getFreeRegions(disks)
    allocatePartitions(storage, disks, partitions, free)
    growPartitions(disks, partitions, free)

    # The number and thus the name of partitions may have changed now,
    # allocatePartitions() takes care of this for new partitions, but not
    # for pre-existing ones, so we update the name of all partitions here
    for part in storage.partitions:
        # needed because of XXX hack below
        if part.isExtended:
            continue
        part.updateName()

    # XXX hack -- if we created any extended partitions we need to add
    #             them to the tree now
    for disk in disks:
        extended = disk.format.extendedPartition
        if not extended:
            # remove any obsolete extended partitions
            for part in storage.partitions:
                if part.disk == disk and part.isExtended:
                    storage.devicetree._removeDevice(part, moddisk=False)
            continue

        extendedName = devicePathToName(extended.getDeviceNodeName())
        # remove any obsolete extended partitions
        for part in storage.partitions:
            if part.disk == disk and part.isExtended and \
               part.name != extendedName:
                storage.devicetree._removeDevice(part, moddisk=False)

        device = storage.devicetree.getDeviceByName(extendedName)
        if device:
            if not device.exists:
                # created by us, update partedPartition
                device.partedPartition = extended
            continue

        # This is a little odd because normally instantiating a partition
        # that does not exist means leaving self.parents empty and instead
        # populating self.req_disks. In this case, we need to skip past
        # that since this partition is already defined.
        device = PartitionDevice(extendedName, parents=disk)
        device.parents = [disk]
        device.partedPartition = extended
        # just add the device for now -- we'll handle actions at the last
        # moment to simplify things
        storage.devicetree._addDevice(device)

def allocatePartitions(storage, disks, partitions, freespace):
    """ Allocate partitions based on requested features.

        Non-existing partitions are sorted according to their requested
        attributes, and then allocated.

        The basic approach to sorting is that the more specifically-
        defined a request is, the earlier it will be allocated. See
        the function partitionCompare for details on the sorting
        criteria.

        The PartitionDevice instances will have their name and parents
        attributes set once they have been allocated.
    """
    log.debug("allocatePartitions: disks=%s ; partitions=%s" %
                ([d.name for d in disks],
                 ["%s(id %d)" % (p.name, p.id) for p in partitions]))

    new_partitions = [p for p in partitions if not p.exists]
    new_partitions.sort(cmp=partitionCompare)

    # the following dicts all use device path strings as keys
    disklabels = {}     # DiskLabel instances for each disk
    all_disks = {}      # StorageDevice for each disk
    for disk in disks:
        if disk.path not in disklabels.keys():
            disklabels[disk.path] = disk.format
            all_disks[disk.path] = disk

    removeNewPartitions(disks, new_partitions)

    for _part in new_partitions:
        if _part.partedPartition and _part.isExtended:
            # ignore new extendeds as they are implicit requests
            continue

        # obtain the set of candidate disks
        req_disks = []
        if _part.disk:
            # we have a already selected a disk for this request
            req_disks = [_part.disk]
        elif _part.req_disks:
            # use the requested disk set
            req_disks = _part.req_disks
        else:
            # no disks specified means any disk will do
            req_disks = disks

        req_disks.sort(key=lambda d: d.name, cmp=storage.compareDisks)
        log.debug("allocating partition: %s ; id: %d ; disks: %s ;\n"
                  "boot: %s ; primary: %s ; size: %dMB ; grow: %s ; "
                  "max_size: %s" % (_part.name, _part.id, req_disks,
                                    _part.req_bootable, _part.req_primary,
                                    _part.req_size, _part.req_grow,
                                    _part.req_max_size))
        free = None
        use_disk = None
        part_type = None
        growth = 0
        # loop through disks
        for _disk in req_disks:
            disklabel = disklabels[_disk.path]
            sectorSize = disklabel.partedDevice.sectorSize
            best = None
            current_free = free

            # for growable requests, we don't want to pass the current free
            # geometry to getBestFreeRegion -- this allows us to try the
            # best region from each disk and choose one based on the total
            # growth it allows
            if _part.req_grow:
                current_free = None

            log.debug("checking freespace on %s" % _disk.name)

            new_part_type = getNextPartitionType(disklabel.partedDisk)
            if new_part_type is None:
                # can't allocate any more partitions on this disk
                log.debug("no free partition slots on %s" % _disk.name)
                continue

            if _part.req_primary and new_part_type != parted.PARTITION_NORMAL:
                if (disklabel.partedDisk.primaryPartitionCount <
                    disklabel.partedDisk.maxPrimaryPartitionCount):
                    # don't fail to create a primary if there are only three
                    # primary partitions on the disk (#505269)
                    new_part_type = parted.PARTITION_NORMAL
                else:
                    # we need a primary slot and none are free on this disk
                    log.debug("no primary slots available on %s" % _disk.name)
                    continue

            best = getBestFreeSpaceRegion(disklabel.partedDisk,
                                          new_part_type,
                                          _part.req_size,
                                          best_free=current_free,
                                          boot=_part.req_bootable,
                                          grow=_part.req_grow)

            if best == free and not _part.req_primary and \
               new_part_type == parted.PARTITION_NORMAL:
                # see if we can do better with a logical partition
                log.debug("not enough free space for primary -- trying logical")
                new_part_type = getNextPartitionType(disklabel.partedDisk,
                                                     no_primary=True)
                if new_part_type:
                    best = getBestFreeSpaceRegion(disklabel.partedDisk,
                                                  new_part_type,
                                                  _part.req_size,
                                                  best_free=current_free,
                                                  boot=_part.req_bootable,
                                                  grow=_part.req_grow)

            if best and free != best:
                update = True
                if _part.req_grow:
                    log.debug("evaluating growth potential for new layout")
                    new_growth = 0
                    for disk_path in disklabels.keys():
                        log.debug("calculating growth for disk %s" % disk_path)
                        # Now we check, for growable requests, which of the two
                        # free regions will allow for more growth.

                        # set up chunks representing the disks' layouts
                        temp_parts = []
                        for _p in new_partitions[:new_partitions.index(_part)]:
                            if _p.disk.path == disk_path:
                                temp_parts.append(_p)

                        # add the current request to the temp disk to set up
                        # its partedPartition attribute with a base geometry
                        if disk_path == _disk.path:
                            temp_part = addPartition(disklabel,
                                                     best,
                                                     new_part_type,
                                                     _part.req_size)
                            _part.partedPartition = temp_part
                            _part.disk = _disk
                            temp_parts.append(_part)

                        chunks = getDiskChunks(all_disks[disk_path],
                                               temp_parts, freespace)

                        # grow all growable requests
                        disk_growth = 0
                        disk_sector_size = disklabels[disk_path].partedDevice.sectorSize
                        for chunk in chunks:
                            chunk.growRequests()
                            # record the growth for this layout
                            new_growth += chunk.growth
                            disk_growth += chunk.growth
                            for req in chunk.requests:
                                log.debug("request %d (%s) growth: %d (%dMB) "
                                          "size: %dMB" %
                                          (req.partition.id,
                                           req.partition.name,
                                           req.growth,
                                           sectorsToSize(req.growth,
                                                         disk_sector_size),
                                           sectorsToSize(req.growth + req.base,
                                                         disk_sector_size)))
                        log.debug("disk %s growth: %d (%dMB)" %
                                        (disk_path, disk_growth,
                                         sectorsToSize(disk_growth,
                                                       disk_sector_size)))

                    disklabel.partedDisk.removePartition(temp_part)
                    _part.partedPartition = None
                    _part.disk = None

                    log.debug("total growth: %d sectors" % new_growth)

                    # update the chosen free region unless the previous
                    # choice yielded greater total growth
                    if new_growth < growth:
                        log.debug("keeping old free: %d < %d" % (new_growth,
                                                                 growth))
                        update = False
                    else:
                        growth = new_growth

                if update:
                    # now we know we are choosing a new free space,
                    # so update the disk and part type
                    log.debug("updating use_disk to %s (%s), type: %s"
                                % (_disk, _disk.name, new_part_type))
                    part_type = new_part_type
                    use_disk = _disk
                    log.debug("new free: %s (%d-%d / %dMB)" % (best,
                                                               best.start,
                                                               best.end,
                                                               best.getSize()))
                    log.debug("new free allows for %d sectors of growth" %
                                growth)
                    free = best

            # For platforms with a fake boot partition (like Apple Bootstrap or
            # PReP) and multiple disks, we need to ensure the /boot partition
            # ends up on the same disk as the fake one.
            mountpoint = getattr(_part.format, "mountpoint", "")
            if not mountpoint:
                mountpoint = ""

            if free and (_part.req_bootable or mountpoint.startswith("/boot")):
                # if this is a bootable partition we want to
                # use the first freespace region large enough
                # to satisfy the request
                log.debug("found free space for bootable request")
                break

        if free is None:
            raise PartitioningError("not enough free space on disks")

        _disk = use_disk
        disklabel = _disk.format

        # create the extended partition if needed
        if part_type == parted.PARTITION_EXTENDED:
            log.debug("creating extended partition")
            addPartition(disklabel, free, part_type, None)

            # now the extended partition exists, so set type to logical
            part_type = parted.PARTITION_LOGICAL

            # recalculate freespace
            log.debug("recalculating free space")
            free = getBestFreeSpaceRegion(disklabel.partedDisk,
                                          part_type,
                                          _part.req_size,
                                          boot=_part.req_bootable,
                                          grow=_part.req_grow)
            if not free:
                raise PartitioningError("not enough free space after "
                                        "creating extended partition")

        partition = addPartition(disklabel, free, part_type, _part.req_size)
        log.debug("created partition %s of %dMB and added it to %s" %
                (partition.getDeviceNodeName(), partition.getSize(),
                 disklabel.device))

        # this one sets the name
        _part.partedPartition = partition
        _part.disk = _disk

        # parted modifies the partition in the process of adding it to
        # the disk, so we need to grab the latest version...
        _part.partedPartition = disklabel.partedDisk.getPartitionByPath(_part.path)


class Request(object):
    """ A partition request.

        Request instances are used for calculating how much to grow
        partitions.
    """
    def __init__(self, partition):
        """ Create a Request instance.

            Arguments:

                partition -- a PartitionDevice instance

        """
        self.partition = partition          # storage.devices.PartitionDevice
        self.growth = 0                     # growth in sectors
        self.max_growth = 0                 # max growth in sectors
        self.done = not partition.req_grow  # can we grow this request more?
        self.base = partition.partedPartition.geometry.length   # base sectors

        sector_size = partition.partedPartition.disk.device.sectorSize

        if partition.req_grow:
            limits = filter(lambda l: l > 0,
                        [sizeToSectors(partition.req_max_size, sector_size),
                         sizeToSectors(partition.format.maxSize, sector_size),
                         partition.partedPartition.disk.maxPartitionLength])

            if limits:
                max_sectors = min(limits)
                self.max_growth = max_sectors - self.base

    @property
    def growable(self):
        """ True if this request is growable. """
        return self.partition.req_grow

    @property
    def id(self):
        """ The id of the PartitionDevice this request corresponds to. """
        return self.partition.id

    def __str__(self):
        s = ("%(type)s instance --\n"
             "id = %(id)s  name = %(name)s  growable = %(growable)\n"
             "base = %(base)d  growth = %(grow)d  max_grow = %(max_grow)d\n"
             "done = %(done)s" %
             {"type": self.__class__.__name__, "id": self.id,
              "name": self.partition.name, "growable": self.growable,
              "base": self.base, "growth": self.growth,
              "max_grow": self.max_growth, "done": self.done})
        return s


class Chunk(object):
    """ A free region on disk from which partitions will be allocated """
    def __init__(self, geometry, requests=None):
        """ Create a Chunk instance.

            Arguments:

                geometry -- parted.Geometry instance describing the free space


            Keyword Arguments:

                requests -- list of Request instances allocated from this chunk

        """
        self.geometry = geometry            # parted.Geometry
        self.pool = self.geometry.length    # free sector count
        self.sectorSize = self.geometry.device.sectorSize
        self.base = 0                       # sum of growable requests' base
                                            # sizes, in sectors
        self.requests = []                  # list of Request instances
        if isinstance(requests, list):
            for req in requests:
                self.addRequest(req)

    def __str__(self):
        s = ("%(type)s instance --\n"
             "device = %(device)s  start = %(start)d  end = %(end)d\n"
             "length = %(length)d  size = %(size)d pool = %(pool)d\n"
             "remaining = %(rem)d  sectorSize = %(sectorSize)d" %
             {"type": self.__class__.__name__,
              "device": self.geometry.device.path,
              "start": self.geometry.start, "end": self.geometry.end,
              "length": self.geometry.length, "size": self.geometry.getSize(),
              "pool": self.pool, "rem": self.remaining,
              "sectorSize": self.sectorSize})

        return s

    def addRequest(self, req):
        """ Add a Request to this chunk. """
        log.debug("adding request %d to chunk %s" % (req.partition.id, self))
        self.requests.append(req)
        self.pool -= req.base

        if not req.done:
            self.base += req.base

    def getRequestByID(self, id):
        """ Retrieve a request from this chunk based on its id. """
        for request in self.requests:
            if request.id == id:
                return request

    @property
    def growth(self):
        """ Sum of growth in sectors for all requests in this chunk. """
        return sum(r.growth for r in self.requests)

    @property
    def hasGrowable(self):
        """ True if this chunk contains at least one growable request. """
        for req in self.requests:
            if req.growable:
                return True
        return False

    @property
    def remaining(self):
        """ Number of requests still being grown in this chunk. """
        return len([d for d in self.requests if not d.done])

    @property
    def done(self):
        """ True if we are finished growing all requests in this chunk. """
        return self.remaining == 0

    def trimOverGrownRequest(self, req, base=None):
        """ Enforce max growth and return extra sectors to the pool. """
        if req.max_growth and req.growth >= req.max_growth:
            if req.growth > req.max_growth:
                # we've grown beyond the maximum. put some back.
                extra = req.growth - req.max_growth
                log.debug("taking back %d (%dMB) from %d (%s)" %
                            (extra,
                             sectorsToSize(extra, self.sectorSize),
                             req.partition.id, req.partition.name))
                self.pool += extra
                req.growth = req.max_growth

            # We're done growing this partition, so it no longer
            # factors into the growable base used to determine
            # what fraction of the pool each request gets.
            if base is not None:
                base -= req.base
            req.done = True

        return base

    def growRequests(self):
        """ Calculate growth amounts for requests in this chunk. """
        log.debug("Chunk.growRequests: %s" % self)

        # sort the partitions by start sector
        self.requests.sort(key=lambda r: r.partition.partedPartition.geometry.start)

        # we use this to hold the base for the next loop through the
        # chunk's requests since we want the base to be the same for
        # all requests in any given growth iteration
        new_base = self.base
        last_pool = 0 # used to track changes to the pool across iterations
        while not self.done and self.pool and last_pool != self.pool:
            last_pool = self.pool    # to keep from getting stuck
            self.base = new_base
            log.debug("%d partitions and %d (%dMB) left in chunk" %
                        (self.remaining, self.pool,
                         sectorsToSize(self.pool, self.sectorSize)))
            for p in self.requests:
                if p.done:
                    continue

                # Each partition is allocated free sectors from the pool
                # based on the relative _base_ sizes of the remaining
                # growable partitions.
                share = p.base / float(self.base)
                growth = int(share * last_pool) # truncate, don't round
                p.growth += growth
                self.pool -= growth
                log.debug("adding %d (%dMB) to %d (%s)" %
                            (growth,
                             sectorsToSize(growth, self.sectorSize),
                             p.partition.id, p.partition.name))

                new_base = self.trimOverGrownRequest(p, base=new_base)
                log.debug("new grow amount for partition %d (%s) is %d "
                          "sectors, or %dMB" %
                            (p.partition.id, p.partition.name, p.growth,
                             sectorsToSize(p.growth, self.sectorSize)))

        if self.pool:
            # allocate any leftovers in pool to the first partition
            # that can still grow
            for p in self.requests:
                if p.done:
                    continue

                p.growth += self.pool
                self.pool = 0

                self.trimOverGrownRequest(p)
                if self.pool == 0:
                    break


def getDiskChunks(disk, partitions, free):
    """ Return a list of Chunk instances representing a disk.

        Arguments:

            disk -- a StorageDevice with a DiskLabel format
            partitions -- list of PartitionDevice instances
            free -- list of parted.Geometry instances representing free space

        Partitions and free regions not on the specified disk are ignored.

    """
    # list of all new partitions on this disk
    disk_parts = [p for p in partitions if p.disk == disk and not p.exists]
    disk_free = [f for f in free if f.device.path == disk.path]


    chunks = [Chunk(f) for f in disk_free]

    for p in disk_parts:
        if p.isExtended:
            # handle extended partitions specially since they are
            # indeed very special
            continue

        for i, f in enumerate(disk_free):
            if f.contains(p.partedPartition.geometry):
                chunks[i].addRequest(Request(p))
                break

    return chunks

def growPartitions(disks, partitions, free):
    """ Grow all growable partition requests.

        Partitions have already been allocated from chunks of free space on
        the disks. This function does not modify the ordering of partitions
        or the free chunks from which they are allocated.

        Free space within a given chunk is allocated to each growable
        partition allocated from that chunk in an amount corresponding to
        the ratio of that partition's base size to the sum of the base sizes
        of all growable partitions allocated from the chunk.

        Arguments:

            disks -- a list of all usable disks (DiskDevice instances)
            partitions -- a list of all partitions (PartitionDevice instances)
            free -- a list of all free regions (parted.Geometry instances)
    """
    log.debug("growPartitions: disks=%s, partitions=%s" %
            ([d.name for d in disks],
             ["%s(id %d)" % (p.name, p.id) for p in partitions]))
    all_growable = [p for p in partitions if p.req_grow]
    if not all_growable:
        log.debug("no growable partitions")
        return

    log.debug("growable partitions are %s" % [p.name for p in all_growable])

    for disk in disks:
        log.debug("growing partitions on %s" % disk.name)
        sector_size = disk.format.partedDevice.sectorSize

        # find any extended partition on this disk
        extended_geometry = getattr(disk.format.extendedPartition,
                                    "geometry",
                                    None)  # parted.Geometry

        # list of free space regions on this disk prior to partition allocation
        disk_free = [f for f in free if f.device.path == disk.path]
        if not disk_free:
            log.debug("no free space on %s" % disk.name)
            continue

        chunks = getDiskChunks(disk, partitions, disk_free)
        log.debug("disk %s has %d chunks" % (disk.name, len(chunks)))
        # grow the partitions in each chunk as a group
        for chunk in chunks:
            if not chunk.hasGrowable:
                # no growable partitions in this chunk
                continue

            chunk.growRequests()

            # recalculate partition geometries
            disklabel = disk.format
            start = chunk.geometry.start
            new_partitions = []
            for p in chunk.requests:
                ptype = p.partition.partedPartition.type
                log.debug("partition %s (%d): %s" % (p.partition.name,
                                                     p.partition.id, ptype))
                if ptype == parted.PARTITION_EXTENDED:
                    continue

                # XXX since we need one metadata sector before each
                #     logical partition we burn one logical block to
                #     safely align the start of each logical partition
                if ptype == parted.PARTITION_LOGICAL:
                    start += disklabel.alignment.grainSize

                old_geometry = p.partition.partedPartition.geometry
                new_length = p.base + p.growth
                end = start + new_length - 1
                # align end sector as needed
                if not disklabel.endAlignment.isAligned(chunk.geometry, end):
                    end = disklabel.endAlignment.alignDown(chunk.geometry, end)
                new_geometry = parted.Geometry(device=disklabel.partedDevice,
                                               start=start,
                                               end=end)
                log.debug("new geometry for %s: %s" % (p.partition.name,
                                                       new_geometry))
                start = end + 1
                new_partition = parted.Partition(disk=disklabel.partedDisk,
                                                 type=ptype,
                                                 geometry=new_geometry)
                new_partitions.append((new_partition, p.partition))

            # remove all new partitions from this chunk
            removeNewPartitions([disk], [r.partition for r in chunk.requests])
            log.debug("back from removeNewPartitions")

            # adjust the extended partition as needed
            # we will ony resize an extended partition that we created
            log.debug("extended: %s" % extended_geometry)
            if extended_geometry and \
               chunk.geometry.contains(extended_geometry):
                log.debug("setting up new geometry for extended on %s" % disk.name)
                ext_start = 0
                ext_end = 0
                for (partition, device) in new_partitions:
                    if partition.type != parted.PARTITION_LOGICAL:
                        continue

                    if not ext_start or partition.geometry.start < ext_start:
                        # account for the logical block difference in start
                        # sector for the extended -v- first logical
                        # (partition.geometry.start is already aligned)
                        ext_start = partition.geometry.start - disklabel.alignment.grainSize

                    if not ext_end or partition.geometry.end > ext_end:
                        ext_end = partition.geometry.end

                new_geometry = parted.Geometry(device=disklabel.partedDevice,
                                               start=ext_start,
                                               end=ext_end)
                log.debug("new geometry for extended: %s" % new_geometry)
                new_extended = parted.Partition(disk=disklabel.partedDisk,
                                                type=parted.PARTITION_EXTENDED,
                                                geometry=new_geometry)
                ptypes = [p.type for (p, d) in new_partitions]
                for pt_idx, ptype in enumerate(ptypes):
                    if ptype == parted.PARTITION_LOGICAL:
                        new_partitions.insert(pt_idx, (new_extended, None))
                        break

            # add the partitions with their new geometries to the disk
            for (partition, device) in new_partitions:
                if device:
                    name = device.name
                else:
                    # If there was no extended partition on this disk when
                    # doPartitioning was called we won't have a
                    # PartitionDevice instance for it.
                    name = partition.getDeviceNodeName()

                log.debug("setting %s new geometry: %s" % (name,
                                                           partition.geometry))
                constraint = parted.Constraint(exactGeom=partition.geometry)
                disklabel.partedDisk.addPartition(partition=partition,
                                                  constraint=constraint)
                path = partition.path
                if device:
                    # set the device's name
                    device.partedPartition = partition
                    # without this, the path attr will be a basename. eek.
                    device.disk = disk

                    # make sure we store the disk's version of the partition
                    newpart = disklabel.partedDisk.getPartitionByPath(path)
                    device.partedPartition = newpart


def hasFreeDiskSpace(storage, exclusiveDisks=None):
    """Returns True if there is at least 100Mb of free usable space in any of
       the disks.  False otherwise.

    """
    # FIXME: This function needs to be implemented.  It is used, at least, by
    # iw/partition_gui.py.  It should be implemented after the new
    # doPartitioning code is commited for fedora 13.  Since it returns True
    # the user will always be able to access the create partition screen. If
    # no partition can be created, the user will go back to the previous
    # storage state after seeing a warning message.
    return True


def lvCompare(lv1, lv2):
    """ More specifically defined lvs come first.

        < 1 => x < y
          0 => x == y
        > 1 => x > y
    """
    ret = 0

    # larger requests go to the front of the list
    ret -= cmp(lv1.size, lv2.size) * 100

    # fixed size requests to the front
    ret += cmp(lv1.req_grow, lv2.req_grow) * 50

    # potentially larger growable requests go to the front
    if lv1.req_grow and lv2.req_grow:
        if not lv1.req_max_size and lv2.req_max_size:
            ret -= 25
        elif lv1.req_max_size and not lv2.req_max_size:
            ret += 25
        else:
            ret -= cmp(lv1.req_max_size, lv2.req_max_size) * 25

    if ret > 0:
        ret = 1
    elif ret < 0:
        ret = -1

    return ret

def growLVM(storage):
    """ Grow LVs according to the sizes of the PVs. """
    for vg in storage.vgs:
        total_free = vg.freeSpace
        if total_free < 0:
            # by now we have allocated the PVs so if there isn't enough
            # space in the VG we have a real problem
            raise PartitioningError("not enough space for LVM requests")
        elif not total_free:
            log.debug("vg %s has no free space" % vg.name)
            continue

        log.debug("vg %s: %dMB free ; lvs: %s" % (vg.name, vg.freeSpace,
                                                  [l.lvname for l in vg.lvs]))

        # figure out how much to grow each LV
        grow_amounts = {}
        lv_total = vg.size - total_free
        log.debug("used: %dMB ; vg.size: %dMB" % (lv_total, vg.size))

        # This first loop is to calculate percentage-based growth
        # amounts. These are based on total free space.
        lvs = vg.lvs
        lvs.sort(cmp=lvCompare)
        for lv in lvs:
            if not lv.req_grow or not lv.req_percent:
                continue

            portion = (lv.req_percent * 0.01)
            grow = portion * vg.vgFree
            new_size = lv.req_size + grow
            if lv.req_max_size and new_size > lv.req_max_size:
                grow -= (new_size - lv.req_max_size)

            if lv.format.maxSize and lv.format.maxSize < new_size:
                grow -= (new_size - lv.format.maxSize)

            # clamp growth amount to a multiple of vg extent size
            grow_amounts[lv.name] = vg.align(grow)
            total_free -= grow
            lv_total += grow

        # This second loop is to calculate non-percentage-based growth
        # amounts. These are based on free space remaining after
        # calculating percentage-based growth amounts.

        # keep a tab on space not allocated due to format or requested
        # maximums -- we'll dole it out to subsequent requests
        leftover = 0
        for lv in lvs:
            log.debug("checking lv %s: req_grow: %s ; req_percent: %s"
                      % (lv.name, lv.req_grow, lv.req_percent))
            if not lv.req_grow or lv.req_percent:
                continue

            portion = float(lv.req_size) / float(lv_total)
            grow = portion * total_free
            log.debug("grow is %dMB" % grow)

            todo = lvs[lvs.index(lv):]
            unallocated = reduce(lambda x,y: x+y,
                                 [l.req_size for l in todo
                                  if l.req_grow and not l.req_percent])
            extra_portion = float(lv.req_size) / float(unallocated)
            extra = extra_portion * leftover
            log.debug("%s getting %dMB (%d%%) of %dMB leftover space"
                      % (lv.name, extra, extra_portion * 100, leftover))
            leftover -= extra
            grow += extra
            log.debug("grow is now %dMB" % grow)
            max_size = lv.req_size + grow
            if lv.req_max_size and max_size > lv.req_max_size:
                max_size = lv.req_max_size

            if lv.format.maxSize and max_size > lv.format.maxSize:
                max_size = lv.format.maxSize

            log.debug("max size is %dMB" % max_size)
            max_size = max_size
            leftover += (lv.req_size + grow) - max_size
            grow = max_size - lv.req_size
            log.debug("lv %s gets %dMB" % (lv.name, vg.align(grow)))
            grow_amounts[lv.name] = vg.align(grow)

        if not grow_amounts:
            log.debug("no growable lvs in vg %s" % vg.name)
            continue

        # now grow the lvs by the amounts we've calculated above
        for lv in lvs:
            if lv.name not in grow_amounts.keys():
                continue
            lv.size += grow_amounts[lv.name]

        # now there shouldn't be any free space left, but if there is we
        # should allocate it to one of the LVs
        vg_free = vg.freeSpace
        log.debug("vg %s has %dMB free" % (vg.name, vg_free))
        if vg_free:
            for lv in lvs:
                if not lv.req_grow:
                    continue

                if lv.req_max_size and lv.size == lv.req_max_size:
                    continue

                if lv.format.maxSize and lv.size == lv.format.maxSize:
                    continue

                # first come, first served
                projected = lv.size + vg.freeSpace
                if lv.req_max_size and projected > lv.req_max_size:
                    projected = lv.req_max_size

                if lv.format.maxSize and projected > lv.format.maxSize:
                    projected = lv.format.maxSize

                log.debug("giving leftover %dMB to %s" % (projected - lv.size,
                                                          lv.name))
                lv.size = projected