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#
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#

# Copyright (C) 2006, 2007 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty 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.


"""Block device abstraction"""

import re
import time
import errno
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import pyparsing as pyp
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import os
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import logging
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from ganeti import utils
from ganeti import errors
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from ganeti import constants
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from ganeti import objects
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# Size of reads in _CanReadDevice
_DEVICE_READ_SIZE = 128 * 1024


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def _IgnoreError(fn, *args, **kwargs):
  """Executes the given function, ignoring BlockDeviceErrors.

  This is used in order to simplify the execution of cleanup or
  rollback functions.

  @rtype: boolean
  @return: True when fn didn't raise an exception, False otherwise

  """
  try:
    fn(*args, **kwargs)
    return True
  except errors.BlockDeviceError, err:
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    logging.warning("Caught BlockDeviceError but ignoring: %s", str(err))
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    return False


def _ThrowError(msg, *args):
  """Log an error to the node daemon and the raise an exception.

  @type msg: string
  @param msg: the text of the exception
  @raise errors.BlockDeviceError

  """
  if args:
    msg = msg % args
  logging.error(msg)
  raise errors.BlockDeviceError(msg)


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def _CanReadDevice(path):
  """Check if we can read from the given device.

  This tries to read the first 128k of the device.

  """
  try:
    utils.ReadFile(path, size=_DEVICE_READ_SIZE)
    return True
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  except EnvironmentError:
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    logging.warning("Can't read from device %s", path, exc_info=True)
    return False


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class BlockDev(object):
  """Block device abstract class.

  A block device can be in the following states:
    - not existing on the system, and by `Create()` it goes into:
    - existing but not setup/not active, and by `Assemble()` goes into:
    - active read-write and by `Open()` it goes into
    - online (=used, or ready for use)

  A device can also be online but read-only, however we are not using
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  the readonly state (LV has it, if needed in the future) and we are
  usually looking at this like at a stack, so it's easier to
  conceptualise the transition from not-existing to online and back
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  like a linear one.

  The many different states of the device are due to the fact that we
  need to cover many device types:
    - logical volumes are created, lvchange -a y $lv, and used
    - drbd devices are attached to a local disk/remote peer and made primary

  A block device is identified by three items:
    - the /dev path of the device (dynamic)
    - a unique ID of the device (static)
    - it's major/minor pair (dynamic)

  Not all devices implement both the first two as distinct items. LVM
  logical volumes have their unique ID (the pair volume group, logical
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  volume name) in a 1-to-1 relation to the dev path. For DRBD devices,
  the /dev path is again dynamic and the unique id is the pair (host1,
  dev1), (host2, dev2).
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  You can get to a device in two ways:
    - creating the (real) device, which returns you
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      an attached instance (lvcreate)
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    - attaching of a python instance to an existing (real) device

  The second point, the attachement to a device, is different
  depending on whether the device is assembled or not. At init() time,
  we search for a device with the same unique_id as us. If found,
  good. It also means that the device is already assembled. If not,
  after assembly we'll have our correct major/minor.

  """
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  def __init__(self, unique_id, children, size):
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    self._children = children
    self.dev_path = None
    self.unique_id = unique_id
    self.major = None
    self.minor = None
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    self.attached = False
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    self.size = size
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  def Assemble(self):
    """Assemble the device from its components.

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    Implementations of this method by child classes must ensure that:
      - after the device has been assembled, it knows its major/minor
        numbers; this allows other devices (usually parents) to probe
        correctly for their children
      - calling this method on an existing, in-use device is safe
      - if the device is already configured (and in an OK state),
        this method is idempotent
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    """
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    pass
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  def Attach(self):
    """Find a device which matches our config and attach to it.

    """
    raise NotImplementedError

  def Close(self):
    """Notifies that the device will no longer be used for I/O.

    """
    raise NotImplementedError

  @classmethod
  def Create(cls, unique_id, children, size):
    """Create the device.

    If the device cannot be created, it will return None
    instead. Error messages go to the logging system.

    Note that for some devices, the unique_id is used, and for other,
    the children. The idea is that these two, taken together, are
    enough for both creation and assembly (later).

    """
    raise NotImplementedError

  def Remove(self):
    """Remove this device.

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    This makes sense only for some of the device types: LV and file
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    storage. Also note that if the device can't attach, the removal
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    can't be completed.
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    """
    raise NotImplementedError

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  def Rename(self, new_id):
    """Rename this device.

    This may or may not make sense for a given device type.

    """
    raise NotImplementedError

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  def Open(self, force=False):
    """Make the device ready for use.

    This makes the device ready for I/O. For now, just the DRBD
    devices need this.

    The force parameter signifies that if the device has any kind of
    --force thing, it should be used, we know what we are doing.

    """
    raise NotImplementedError

  def Shutdown(self):
    """Shut down the device, freeing its children.

    This undoes the `Assemble()` work, except for the child
    assembling; as such, the children on the device are still
    assembled after this call.

    """
    raise NotImplementedError

  def SetSyncSpeed(self, speed):
    """Adjust the sync speed of the mirror.

    In case this is not a mirroring device, this is no-op.

    """
    result = True
    if self._children:
      for child in self._children:
        result = result and child.SetSyncSpeed(speed)
    return result

  def GetSyncStatus(self):
    """Returns the sync status of the device.

    If this device is a mirroring device, this function returns the
    status of the mirror.

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    If sync_percent is None, it means the device is not syncing.
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    If estimated_time is None, it means we can't estimate
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    the time needed, otherwise it's the time left in seconds.

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    If is_degraded is True, it means the device is missing
    redundancy. This is usually a sign that something went wrong in
    the device setup, if sync_percent is None.

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    The ldisk parameter represents the degradation of the local
    data. This is only valid for some devices, the rest will always
    return False (not degraded).

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    @rtype: objects.BlockDevStatus
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    """
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    return objects.BlockDevStatus(dev_path=self.dev_path,
                                  major=self.major,
                                  minor=self.minor,
                                  sync_percent=None,
                                  estimated_time=None,
                                  is_degraded=False,
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                                  ldisk_status=constants.LDS_OKAY)
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  def CombinedSyncStatus(self):
    """Calculate the mirror status recursively for our children.

    The return value is the same as for `GetSyncStatus()` except the
    minimum percent and maximum time are calculated across our
    children.

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    @rtype: objects.BlockDevStatus

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    """
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    status = self.GetSyncStatus()

    min_percent = status.sync_percent
    max_time = status.estimated_time
    is_degraded = status.is_degraded
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    ldisk_status = status.ldisk_status
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    if self._children:
      for child in self._children:
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        child_status = child.GetSyncStatus()

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        if min_percent is None:
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          min_percent = child_status.sync_percent
        elif child_status.sync_percent is not None:
          min_percent = min(min_percent, child_status.sync_percent)

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        if max_time is None:
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          max_time = child_status.estimated_time
        elif child_status.estimated_time is not None:
          max_time = max(max_time, child_status.estimated_time)

        is_degraded = is_degraded or child_status.is_degraded
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        if ldisk_status is None:
          ldisk_status = child_status.ldisk_status
        elif child_status.ldisk_status is not None:
          ldisk_status = max(ldisk_status, child_status.ldisk_status)
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    return objects.BlockDevStatus(dev_path=self.dev_path,
                                  major=self.major,
                                  minor=self.minor,
                                  sync_percent=min_percent,
                                  estimated_time=max_time,
                                  is_degraded=is_degraded,
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                                  ldisk_status=ldisk_status)
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  def SetInfo(self, text):
    """Update metadata with info text.

    Only supported for some device types.

    """
    for child in self._children:
      child.SetInfo(text)

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  def Grow(self, amount):
    """Grow the block device.

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    @param amount: the amount (in mebibytes) to grow with
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    """
    raise NotImplementedError
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  def GetActualSize(self):
    """Return the actual disk size.

    @note: the device needs to be active when this is called

    """
    assert self.attached, "BlockDevice not attached in GetActualSize()"
    result = utils.RunCmd(["blockdev", "--getsize64", self.dev_path])
    if result.failed:
      _ThrowError("blockdev failed (%s): %s",
                  result.fail_reason, result.output)
    try:
      sz = int(result.output.strip())
    except (ValueError, TypeError), err:
      _ThrowError("Failed to parse blockdev output: %s", str(err))
    return sz

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  def __repr__(self):
    return ("<%s: unique_id: %s, children: %s, %s:%s, %s>" %
            (self.__class__, self.unique_id, self._children,
             self.major, self.minor, self.dev_path))


class LogicalVolume(BlockDev):
  """Logical Volume block device.

  """
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  _VALID_NAME_RE = re.compile("^[a-zA-Z0-9+_.-]*$")
  _INVALID_NAMES = frozenset([".", "..", "snapshot", "pvmove"])
  _INVALID_SUBSTRINGS = frozenset(["_mlog", "_mimage"])

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  def __init__(self, unique_id, children, size):
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    """Attaches to a LV device.

    The unique_id is a tuple (vg_name, lv_name)

    """
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    super(LogicalVolume, self).__init__(unique_id, children, size)
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    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
      raise ValueError("Invalid configuration data %s" % str(unique_id))
    self._vg_name, self._lv_name = unique_id
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    self._ValidateName(self._vg_name)
    self._ValidateName(self._lv_name)
    self.dev_path = utils.PathJoin("/dev", self._vg_name, self._lv_name)
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    self._degraded = True
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    self.major = self.minor = self.pe_size = self.stripe_count = None
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    self.Attach()

  @classmethod
  def Create(cls, unique_id, children, size):
    """Create a new logical volume.

    """
    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
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      raise errors.ProgrammerError("Invalid configuration data %s" %
                                   str(unique_id))
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    vg_name, lv_name = unique_id
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    cls._ValidateName(vg_name)
    cls._ValidateName(lv_name)
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    pvs_info = cls.GetPVInfo([vg_name])
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    if not pvs_info:
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      _ThrowError("Can't compute PV info for vg %s", vg_name)
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    pvs_info.sort()
    pvs_info.reverse()
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    pvlist = [ pv[1] for pv in pvs_info ]
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    if utils.any(pvlist, lambda v: ":" in v):
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      _ThrowError("Some of your PVs have the invalid character ':' in their"
                  " name, this is not supported - please filter them out"
                  " in lvm.conf using either 'filter' or 'preferred_names'")
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    free_size = sum([ pv[0] for pv in pvs_info ])
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    current_pvs = len(pvlist)
    stripes = min(current_pvs, constants.LVM_STRIPECOUNT)
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    # The size constraint should have been checked from the master before
    # calling the create function.
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    if free_size < size:
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      _ThrowError("Not enough free space: required %s,"
                  " available %s", size, free_size)
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    cmd = ["lvcreate", "-L%dm" % size, "-n%s" % lv_name]
    # If the free space is not well distributed, we won't be able to
    # create an optimally-striped volume; in that case, we want to try
    # with N, N-1, ..., 2, and finally 1 (non-stripped) number of
    # stripes
    for stripes_arg in range(stripes, 0, -1):
      result = utils.RunCmd(cmd + ["-i%d" % stripes_arg] + [vg_name] + pvlist)
      if not result.failed:
        break
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    if result.failed:
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      _ThrowError("LV create failed (%s): %s",
                  result.fail_reason, result.output)
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    return LogicalVolume(unique_id, children, size)
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  @staticmethod
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  def GetPVInfo(vg_names, filter_allocatable=True):
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    """Get the free space info for PVs in a volume group.

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    @param vg_names: list of volume group names, if empty all will be returned
    @param filter_allocatable: whether to skip over unallocatable PVs
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    @rtype: list
    @return: list of tuples (free_space, name) with free_space in mebibytes
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    """
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    sep = "|"
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    command = ["pvs", "--noheadings", "--nosuffix", "--units=m",
               "-opv_name,vg_name,pv_free,pv_attr", "--unbuffered",
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               "--separator=%s" % sep ]
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    result = utils.RunCmd(command)
    if result.failed:
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      logging.error("Can't get the PV information: %s - %s",
                    result.fail_reason, result.output)
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      return None
    data = []
    for line in result.stdout.splitlines():
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      fields = line.strip().split(sep)
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      if len(fields) != 4:
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        logging.error("Can't parse pvs output: line '%s'", line)
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        return None
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      # (possibly) skip over pvs which are not allocatable
      if filter_allocatable and fields[3][0] != 'a':
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        continue
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      # (possibly) skip over pvs which are not in the right volume group(s)
      if vg_names and fields[1] not in vg_names:
        continue
      data.append((float(fields[2]), fields[0], fields[1]))
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    return data

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  @classmethod
  def _ValidateName(cls, name):
    """Validates that a given name is valid as VG or LV name.

    The list of valid characters and restricted names is taken out of
    the lvm(8) manpage, with the simplification that we enforce both
    VG and LV restrictions on the names.

    """
    if (not cls._VALID_NAME_RE.match(name) or
        name in cls._INVALID_NAMES or
        utils.any(cls._INVALID_SUBSTRINGS, lambda x: x in name)):
      _ThrowError("Invalid LVM name '%s'", name)

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  def Remove(self):
    """Remove this logical volume.

    """
    if not self.minor and not self.Attach():
      # the LV does not exist
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      return
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    result = utils.RunCmd(["lvremove", "-f", "%s/%s" %
                           (self._vg_name, self._lv_name)])
    if result.failed:
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      _ThrowError("Can't lvremove: %s - %s", result.fail_reason, result.output)
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  def Rename(self, new_id):
    """Rename this logical volume.

    """
    if not isinstance(new_id, (tuple, list)) or len(new_id) != 2:
      raise errors.ProgrammerError("Invalid new logical id '%s'" % new_id)
    new_vg, new_name = new_id
    if new_vg != self._vg_name:
      raise errors.ProgrammerError("Can't move a logical volume across"
                                   " volume groups (from %s to to %s)" %
                                   (self._vg_name, new_vg))
    result = utils.RunCmd(["lvrename", new_vg, self._lv_name, new_name])
    if result.failed:
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      _ThrowError("Failed to rename the logical volume: %s", result.output)
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    self._lv_name = new_name
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    self.dev_path = utils.PathJoin("/dev", self._vg_name, self._lv_name)
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  def Attach(self):
    """Attach to an existing LV.

    This method will try to see if an existing and active LV exists
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    which matches our name. If so, its major/minor will be
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    recorded.

    """
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    self.attached = False
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    result = utils.RunCmd(["lvs", "--noheadings", "--separator=,",
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                           "--units=m", "--nosuffix",
                           "-olv_attr,lv_kernel_major,lv_kernel_minor,"
                           "vg_extent_size,stripes", self.dev_path])
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    if result.failed:
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      logging.error("Can't find LV %s: %s, %s",
                    self.dev_path, result.fail_reason, result.output)
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      return False
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    # the output can (and will) have multiple lines for multi-segment
    # LVs, as the 'stripes' parameter is a segment one, so we take
    # only the last entry, which is the one we're interested in; note
    # that with LVM2 anyway the 'stripes' value must be constant
    # across segments, so this is a no-op actually
    out = result.stdout.splitlines()
    if not out: # totally empty result? splitlines() returns at least
                # one line for any non-empty string
      logging.error("Can't parse LVS output, no lines? Got '%s'", str(out))
      return False
    out = out[-1].strip().rstrip(',')
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    out = out.split(",")
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    if len(out) != 5:
      logging.error("Can't parse LVS output, len(%s) != 5", str(out))
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      return False

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    status, major, minor, pe_size, stripes = out
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    if len(status) != 6:
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      logging.error("lvs lv_attr is not 6 characters (%s)", status)
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      return False

    try:
      major = int(major)
      minor = int(minor)
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    except (TypeError, ValueError), err:
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      logging.error("lvs major/minor cannot be parsed: %s", str(err))
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    try:
      pe_size = int(float(pe_size))
    except (TypeError, ValueError), err:
      logging.error("Can't parse vg extent size: %s", err)
      return False

    try:
      stripes = int(stripes)
    except (TypeError, ValueError), err:
      logging.error("Can't parse the number of stripes: %s", err)
      return False

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    self.major = major
    self.minor = minor
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    self.pe_size = pe_size
    self.stripe_count = stripes
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    self._degraded = status[0] == 'v' # virtual volume, i.e. doesn't backing
                                      # storage
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    self.attached = True
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    return True
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  def Assemble(self):
    """Assemble the device.

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    We always run `lvchange -ay` on the LV to ensure it's active before
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    use, as there were cases when xenvg was not active after boot
    (also possibly after disk issues).
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    """
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    result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
    if result.failed:
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      _ThrowError("Can't activate lv %s: %s", self.dev_path, result.output)
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  def Shutdown(self):
    """Shutdown the device.

    This is a no-op for the LV device type, as we don't deactivate the
    volumes on shutdown.

    """
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    pass
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  def GetSyncStatus(self):
    """Returns the sync status of the device.

    If this device is a mirroring device, this function returns the
    status of the mirror.

    For logical volumes, sync_percent and estimated_time are always
    None (no recovery in progress, as we don't handle the mirrored LV
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    case). The is_degraded parameter is the inverse of the ldisk
    parameter.
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    For the ldisk parameter, we check if the logical volume has the
    'virtual' type, which means it's not backed by existing storage
    anymore (read from it return I/O error). This happens after a
    physical disk failure and subsequent 'vgreduce --removemissing' on
    the volume group.
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    The status was already read in Attach, so we just return it.

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    @rtype: objects.BlockDevStatus
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    """
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    if self._degraded:
      ldisk_status = constants.LDS_FAULTY
    else:
      ldisk_status = constants.LDS_OKAY

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    return objects.BlockDevStatus(dev_path=self.dev_path,
                                  major=self.major,
                                  minor=self.minor,
                                  sync_percent=None,
                                  estimated_time=None,
                                  is_degraded=self._degraded,
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                                  ldisk_status=ldisk_status)
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  def Open(self, force=False):
    """Make the device ready for I/O.

    This is a no-op for the LV device type.

    """
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    pass
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  def Close(self):
    """Notifies that the device will no longer be used for I/O.

    This is a no-op for the LV device type.

    """
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    pass
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  def Snapshot(self, size):
    """Create a snapshot copy of an lvm block device.

    """
    snap_name = self._lv_name + ".snap"

    # remove existing snapshot if found
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    snap = LogicalVolume((self._vg_name, snap_name), None, size)
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    _IgnoreError(snap.Remove)
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    pvs_info = self.GetPVInfo([self._vg_name])
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    if not pvs_info:
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      _ThrowError("Can't compute PV info for vg %s", self._vg_name)
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    pvs_info.sort()
    pvs_info.reverse()
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    free_size, _, _ = pvs_info[0]
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    if free_size < size:
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      _ThrowError("Not enough free space: required %s,"
                  " available %s", size, free_size)
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    result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-s",
                           "-n%s" % snap_name, self.dev_path])
    if result.failed:
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      _ThrowError("command: %s error: %s - %s",
                  result.cmd, result.fail_reason, result.output)
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    return snap_name

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  def SetInfo(self, text):
    """Update metadata with info text.

    """
    BlockDev.SetInfo(self, text)

    # Replace invalid characters
    text = re.sub('^[^A-Za-z0-9_+.]', '_', text)
    text = re.sub('[^-A-Za-z0-9_+.]', '_', text)

    # Only up to 128 characters are allowed
    text = text[:128]

    result = utils.RunCmd(["lvchange", "--addtag", text,
                           self.dev_path])
    if result.failed:
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      _ThrowError("Command: %s error: %s - %s", result.cmd, result.fail_reason,
                  result.output)

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  def Grow(self, amount):
    """Grow the logical volume.

    """
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    if self.pe_size is None or self.stripe_count is None:
      if not self.Attach():
        _ThrowError("Can't attach to LV during Grow()")
    full_stripe_size = self.pe_size * self.stripe_count
    rest = amount % full_stripe_size
    if rest != 0:
      amount += full_stripe_size - rest
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    # we try multiple algorithms since the 'best' ones might not have
    # space available in the right place, but later ones might (since
    # they have less constraints); also note that only recent LVM
    # supports 'cling'
    for alloc_policy in "contiguous", "cling", "normal":
      result = utils.RunCmd(["lvextend", "--alloc", alloc_policy,
                             "-L", "+%dm" % amount, self.dev_path])
      if not result.failed:
        return
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    _ThrowError("Can't grow LV %s: %s", self.dev_path, result.output)
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class DRBD8Status(object):
  """A DRBD status representation class.

  Note that this doesn't support unconfigured devices (cs:Unconfigured).

  """
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  UNCONF_RE = re.compile(r"\s*[0-9]+:\s*cs:Unconfigured$")
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  LINE_RE = re.compile(r"\s*[0-9]+:\s*cs:(\S+)\s+(?:st|ro):([^/]+)/(\S+)"
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                       "\s+ds:([^/]+)/(\S+)\s+.*$")
  SYNC_RE = re.compile(r"^.*\ssync'ed:\s*([0-9.]+)%.*"
                       "\sfinish: ([0-9]+):([0-9]+):([0-9]+)\s.*$")

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  CS_UNCONFIGURED = "Unconfigured"
  CS_STANDALONE = "StandAlone"
  CS_WFCONNECTION = "WFConnection"
  CS_WFREPORTPARAMS = "WFReportParams"
  CS_CONNECTED = "Connected"
  CS_STARTINGSYNCS = "StartingSyncS"
  CS_STARTINGSYNCT = "StartingSyncT"
  CS_WFBITMAPS = "WFBitMapS"
  CS_WFBITMAPT = "WFBitMapT"
  CS_WFSYNCUUID = "WFSyncUUID"
  CS_SYNCSOURCE = "SyncSource"
  CS_SYNCTARGET = "SyncTarget"
  CS_PAUSEDSYNCS = "PausedSyncS"
  CS_PAUSEDSYNCT = "PausedSyncT"
  CSET_SYNC = frozenset([
    CS_WFREPORTPARAMS,
    CS_STARTINGSYNCS,
    CS_STARTINGSYNCT,
    CS_WFBITMAPS,
    CS_WFBITMAPT,
    CS_WFSYNCUUID,
    CS_SYNCSOURCE,
    CS_SYNCTARGET,
    CS_PAUSEDSYNCS,
    CS_PAUSEDSYNCT,
    ])

  DS_DISKLESS = "Diskless"
  DS_ATTACHING = "Attaching" # transient state
  DS_FAILED = "Failed" # transient state, next: diskless
  DS_NEGOTIATING = "Negotiating" # transient state
  DS_INCONSISTENT = "Inconsistent" # while syncing or after creation
  DS_OUTDATED = "Outdated"
  DS_DUNKNOWN = "DUnknown" # shown for peer disk when not connected
  DS_CONSISTENT = "Consistent"
  DS_UPTODATE = "UpToDate" # normal state

  RO_PRIMARY = "Primary"
  RO_SECONDARY = "Secondary"
  RO_UNKNOWN = "Unknown"

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  def __init__(self, procline):
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    u = self.UNCONF_RE.match(procline)
    if u:
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      self.cstatus = self.CS_UNCONFIGURED
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      self.lrole = self.rrole = self.ldisk = self.rdisk = None
    else:
      m = self.LINE_RE.match(procline)
      if not m:
        raise errors.BlockDeviceError("Can't parse input data '%s'" % procline)
      self.cstatus = m.group(1)
      self.lrole = m.group(2)
      self.rrole = m.group(3)
      self.ldisk = m.group(4)
      self.rdisk = m.group(5)

    # end reading of data from the LINE_RE or UNCONF_RE
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    self.is_standalone = self.cstatus == self.CS_STANDALONE
    self.is_wfconn = self.cstatus == self.CS_WFCONNECTION
    self.is_connected = self.cstatus == self.CS_CONNECTED
    self.is_primary = self.lrole == self.RO_PRIMARY
    self.is_secondary = self.lrole == self.RO_SECONDARY
    self.peer_primary = self.rrole == self.RO_PRIMARY
    self.peer_secondary = self.rrole == self.RO_SECONDARY
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    self.both_primary = self.is_primary and self.peer_primary
    self.both_secondary = self.is_secondary and self.peer_secondary

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    self.is_diskless = self.ldisk == self.DS_DISKLESS
    self.is_disk_uptodate = self.ldisk == self.DS_UPTODATE
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    self.is_in_resync = self.cstatus in self.CSET_SYNC
    self.is_in_use = self.cstatus != self.CS_UNCONFIGURED
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    m = self.SYNC_RE.match(procline)
    if m:
      self.sync_percent = float(m.group(1))
      hours = int(m.group(2))
      minutes = int(m.group(3))
      seconds = int(m.group(4))
      self.est_time = hours * 3600 + minutes * 60 + seconds
    else:
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      # we have (in this if branch) no percent information, but if
      # we're resyncing we need to 'fake' a sync percent information,
      # as this is how cmdlib determines if it makes sense to wait for
      # resyncing or not
      if self.is_in_resync:
        self.sync_percent = 0
      else:
        self.sync_percent = None
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      self.est_time = None


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class BaseDRBD(BlockDev): # pylint: disable-msg=W0223
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  """Base DRBD class.
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  This class contains a few bits of common functionality between the
  0.7 and 8.x versions of DRBD.

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  """
  _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)"
                           r" \(api:(\d+)/proto:(\d+)(?:-(\d+))?\)")
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  _VALID_LINE_RE = re.compile("^ *([0-9]+): cs:([^ ]+).*$")
  _UNUSED_LINE_RE = re.compile("^ *([0-9]+): cs:Unconfigured$")
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  _DRBD_MAJOR = 147
  _ST_UNCONFIGURED = "Unconfigured"
  _ST_WFCONNECTION = "WFConnection"
  _ST_CONNECTED = "Connected"
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  _STATUS_FILE = "/proc/drbd"

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  @staticmethod
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  def _GetProcData(filename=_STATUS_FILE):
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    """Return data from /proc/drbd.
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    """
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    try:
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      data = utils.ReadFile(filename).splitlines()
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    except EnvironmentError, err:
      if err.errno == errno.ENOENT:
        _ThrowError("The file %s cannot be opened, check if the module"
                    " is loaded (%s)", filename, str(err))
      else:
        _ThrowError("Can't read the DRBD proc file %s: %s", filename, str(err))
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    if not data:
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      _ThrowError("Can't read any data from %s", filename)
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    return data
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  @classmethod
  def _MassageProcData(cls, data):
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    """Transform the output of _GetProdData into a nicer form.
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    @return: a dictionary of minor: joined lines from /proc/drbd
        for that minor
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    """
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    results = {}
    old_minor = old_line = None
    for line in data:
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      if not line: # completely empty lines, as can be returned by drbd8.0+
        continue
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      lresult = cls._VALID_LINE_RE.match(line)
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      if lresult is not None:
        if old_minor is not None:
          results[old_minor] = old_line
        old_minor = int(lresult.group(1))
        old_line = line
      else:
        if old_minor is not None:
          old_line += " " + line.strip()
    # add last line
    if old_minor is not None:
      results[old_minor] = old_line
    return results
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  @classmethod
  def _GetVersion(cls):
    """Return the DRBD version.
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    This will return a dict with keys:
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      - k_major
      - k_minor
      - k_point
      - api
      - proto
      - proto2 (only on drbd > 8.2.X)
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    """
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    proc_data = cls._GetProcData()
    first_line = proc_data[0].strip()
    version = cls._VERSION_RE.match(first_line)
    if not version:
      raise errors.BlockDeviceError("Can't parse DRBD version from '%s'" %
                                    first_line)
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    values = version.groups()
    retval = {'k_major': int(values[0]),
              'k_minor': int(values[1]),
              'k_point': int(values[2]),
              'api': int(values[3]),
              'proto': int(values[4]),
             }
    if values[5] is not None:
      retval['proto2'] = values[5]
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    return retval

  @staticmethod
  def _DevPath(minor):
    """Return the path to a drbd device for a given minor.
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    """
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    return "/dev/drbd%d" % minor
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  @classmethod
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  def GetUsedDevs(cls):
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    """Compute the list of used DRBD devices.
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    """
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    data = cls._GetProcData()
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    used_devs = {}
    for line in data:
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      match = cls._VALID_LINE_RE.match(line)
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      if not match:
        continue
      minor = int(match.group(1))
      state = match.group(2)
      if state == cls._ST_UNCONFIGURED:
        continue
      used_devs[minor] = state, line
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    return used_devs
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  def _SetFromMinor(self, minor):
    """Set our parameters based on the given minor.
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    This sets our minor variable and our dev_path.
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    """
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    if minor is None:
      self.minor = self.dev_path = None
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      self.attached = False
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    else:
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      self.minor = minor
      self.dev_path = self._DevPath(minor)
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      self.attached = True
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  @staticmethod
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  def _CheckMetaSize(meta_device):
    """Check if the given meta device looks like a valid one.
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    This currently only check the size, which must be around
    128MiB.
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    """
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    result = utils.RunCmd(["blockdev", "--getsize", meta_device])
    if result.failed:
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      _ThrowError("Failed to get device size: %s - %s",
                  result.fail_reason, result.output)
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    try:
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      sectors = int(result.stdout)
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    except (TypeError, ValueError):
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      _ThrowError("Invalid output from blockdev: '%s'", result.stdout)
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    bytes = sectors * 512
    if bytes < 128 * 1024 * 1024: # less than 128MiB
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      _ThrowError("Meta device too small (%.2fMib)", (bytes / 1024 / 1024))
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    # the maximum *valid* size of the meta device when living on top
    # of LVM is hard to compute: it depends on the number of stripes
    # and the PE size; e.g. a 2-stripe, 64MB PE will result in a 128MB
    # (normal size), but an eight-stripe 128MB PE will result in a 1GB
    # size meta device; as such, we restrict it to 1GB (a little bit
    # too generous, but making assumptions about PE size is hard)
    if bytes > 1024 * 1024 * 1024:
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      _ThrowError("Meta device too big (%.2fMiB)", (bytes / 1024 / 1024))
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  def Rename(self, new_id):
    """Rename a device.
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    This is not supported for drbd devices.
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    """
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    raise errors.ProgrammerError("Can't rename a drbd device")
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class DRBD8(BaseDRBD):
  """DRBD v8.x block device.

  This implements the local host part of the DRBD device, i.e. it
  doesn't do anything to the supposed peer. If you need a fully
  connected DRBD pair, you need to use this class on both hosts.

  The unique_id for the drbd device is the (local_ip, local_port,
  remote_ip, remote_port) tuple, and it must have two children: the
  data device and the meta_device. The meta device is checked for
  valid size and is zeroed on create.

  """
  _MAX_MINORS = 255
  _PARSE_SHOW = None

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  # timeout constants
  _NET_RECONFIG_TIMEOUT = 60

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  def __init__(self, unique_id, children, size):
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    if children and children.count(None) > 0:
      children = []
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    if len(children) not in (0, 2):
      raise ValueError("Invalid configuration data %s" % str(children))
    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 6:
      raise ValueError("Invalid configuration data %s" % str(unique_id))
    (self._lhost, self._lport,
     self._rhost, self._rport,
     self._aminor, self._secret) = unique_id
    if children:
      if not _CanReadDevice(children[1].dev_path):
        logging.info("drbd%s: Ignoring unreadable meta device", self._aminor)
        children = []
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    super(DRBD8, self).__init__(unique_id, children, size)
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    self.major = self._DRBD_MAJOR
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    version = self._GetVersion()
    if version['k_major'] != 8 :
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      _ThrowError("Mismatch in DRBD kernel version and requested ganeti"
                  " usage: kernel is %s.%s, ganeti wants 8.x",
                  version['k_major'], version['k_minor'])
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    if (self._lhost is not None and self._lhost == self._rhost and
        self._lport == self._rport):
      raise ValueError("Invalid configuration data, same local/remote %s" %
                       (unique_id,))
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    self.Attach()

  @classmethod
  def _InitMeta(cls, minor, dev_path):
    """Initialize a meta device.

    This will not work if the given minor is in use.

    """
    result = utils.RunCmd(["drbdmeta", "--force", cls._DevPath(minor),
                           "v08", dev_path, "0", "create-md"])
    if result.failed:
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      _ThrowError("Can't initialize meta device: %s", result.output)
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  @classmethod
  def _FindUnusedMinor(cls):
    """Find an unused DRBD device.

    This is specific to 8.x as the minors are allocated dynamically,
    so non-existing numbers up to a max minor count are actually free.

    """
    data = cls._GetProcData()

    highest = None
    for line in data:
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      match = cls._UNUSED_LINE_RE.match(line)
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      if match:
        return int(match.group(1))
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      match = cls._VALID_LINE_RE.match(line)
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      if match:
        minor = int(match.group(1))
        highest = max(highest, minor)
    if highest is None: # there are no minors in use at all
      return 0
    if highest >= cls._MAX_MINORS:
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      logging.error("Error: no free drbd minors!")
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      raise errors.BlockDeviceError("Can't find a free DRBD minor")
    return highest + 1

  @classmethod
  def _GetShowParser(cls):
    """Return a parser for `drbd show` output.

    This will either create or return an already-create parser for the
    output of the command `drbd show`.

    """
    if cls._PARSE_SHOW is not None:
      return cls._PARSE_SHOW

    # pyparsing setup
    lbrace = pyp.Literal("{").suppress()
    rbrace = pyp.Literal("}").suppress()
    semi = pyp.Literal(";").suppress()
    # this also converts the value to an int
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    number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))
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    comment = pyp.Literal ("#") + pyp.Optional(pyp.restOfLine)
    defa = pyp.Literal