bdev.py 54.1 KB
Newer Older
Iustin Pop's avatar
Iustin Pop committed
1
#
Iustin Pop's avatar
Iustin Pop committed
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
#

# 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
27
import pyparsing as pyp
Manuel Franceschini's avatar
Manuel Franceschini committed
28
import os
29
import logging
Iustin Pop's avatar
Iustin Pop committed
30 31 32

from ganeti import utils
from ganeti import errors
33
from ganeti import constants
Iustin Pop's avatar
Iustin Pop committed
34 35 36 37 38 39 40 41 42 43 44 45


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
46 47 48
  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
Iustin Pop's avatar
Iustin Pop committed
49 50 51 52 53 54 55 56 57 58 59 60 61 62
  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
63 64 65
  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).
Iustin Pop's avatar
Iustin Pop committed
66 67 68

  You can get to a device in two ways:
    - creating the (real) device, which returns you
69
      an attached instance (lvcreate)
Iustin Pop's avatar
Iustin Pop committed
70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
    - 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.

  """
  def __init__(self, unique_id, children):
    self._children = children
    self.dev_path = None
    self.unique_id = unique_id
    self.major = None
    self.minor = None
85
    self.attached = False
Iustin Pop's avatar
Iustin Pop committed
86 87 88 89

  def Assemble(self):
    """Assemble the device from its components.

90 91 92 93 94 95 96
    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
Iustin Pop's avatar
Iustin Pop committed
97 98

    """
99
    return True
Iustin Pop's avatar
Iustin Pop committed
100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129

  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.

130 131 132
    This makes sense only for some of the device types: LV and file
    storeage. Also note that if the device can't attach, the removal
    can't be completed.
Iustin Pop's avatar
Iustin Pop committed
133 134 135 136

    """
    raise NotImplementedError

Iustin Pop's avatar
Iustin Pop committed
137 138 139 140 141 142 143 144
  def Rename(self, new_id):
    """Rename this device.

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

    """
    raise NotImplementedError

Iustin Pop's avatar
Iustin Pop committed
145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184
  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.

185
    If sync_percent is None, it means the device is not syncing.
Iustin Pop's avatar
Iustin Pop committed
186 187

    If estimated_time is None, it means we can't estimate
188 189
    the time needed, otherwise it's the time left in seconds.

Iustin Pop's avatar
Iustin Pop committed
190 191 192 193
    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.

194 195 196 197
    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).

Iustin Pop's avatar
Iustin Pop committed
198 199 200
    @rtype: tuple
    @return: (sync_percent, estimated_time, is_degraded, ldisk)

Iustin Pop's avatar
Iustin Pop committed
201
    """
202
    return None, None, False, False
Iustin Pop's avatar
Iustin Pop committed
203 204 205 206 207 208 209 210 211 212


  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.

    """
213
    min_percent, max_time, is_degraded, ldisk = self.GetSyncStatus()
Iustin Pop's avatar
Iustin Pop committed
214 215
    if self._children:
      for child in self._children:
216
        c_percent, c_time, c_degraded, c_ldisk = child.GetSyncStatus()
Iustin Pop's avatar
Iustin Pop committed
217 218 219 220 221 222 223 224 225
        if min_percent is None:
          min_percent = c_percent
        elif c_percent is not None:
          min_percent = min(min_percent, c_percent)
        if max_time is None:
          max_time = c_time
        elif c_time is not None:
          max_time = max(max_time, c_time)
        is_degraded = is_degraded or c_degraded
226 227
        ldisk = ldisk or c_ldisk
    return min_percent, max_time, is_degraded, ldisk
Iustin Pop's avatar
Iustin Pop committed
228 229


230 231 232 233 234 235 236 237 238
  def SetInfo(self, text):
    """Update metadata with info text.

    Only supported for some device types.

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

239 240 241
  def Grow(self, amount):
    """Grow the block device.

Iustin Pop's avatar
Iustin Pop committed
242
    @param amount: the amount (in mebibytes) to grow with
243 244 245

    """
    raise NotImplementedError
246

Iustin Pop's avatar
Iustin Pop committed
247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267
  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.

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

    The unique_id is a tuple (vg_name, lv_name)

    """
    super(LogicalVolume, self).__init__(unique_id, children)
    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
    self.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)
Iustin Pop's avatar
Iustin Pop committed
268 269
    self._degraded = True
    self.major = self.minor = None
Iustin Pop's avatar
Iustin Pop committed
270 271 272 273 274 275 276 277 278 279 280 281
    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:
      raise ValueError("Invalid configuration data %s" % str(unique_id))
    vg_name, lv_name = unique_id
    pvs_info = cls.GetPVInfo(vg_name)
    if not pvs_info:
282 283
      raise errors.BlockDeviceError("Can't compute PV info for vg %s" %
                                    vg_name)
Iustin Pop's avatar
Iustin Pop committed
284 285
    pvs_info.sort()
    pvs_info.reverse()
286 287 288 289 290 291

    pvlist = [ pv[1] for pv in pvs_info ]
    free_size = sum([ pv[0] for pv in pvs_info ])

    # The size constraint should have been checked from the master before
    # calling the create function.
Iustin Pop's avatar
Iustin Pop committed
292
    if free_size < size:
293 294
      raise errors.BlockDeviceError("Not enough free space: required %s,"
                                    " available %s" % (size, free_size))
Iustin Pop's avatar
Iustin Pop committed
295
    result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-n%s" % lv_name,
296
                           vg_name] + pvlist)
Iustin Pop's avatar
Iustin Pop committed
297
    if result.failed:
298 299
      raise errors.BlockDeviceError("%s - %s" % (result.fail_reason,
                                                result.output))
Iustin Pop's avatar
Iustin Pop committed
300 301 302 303 304 305
    return LogicalVolume(unique_id, children)

  @staticmethod
  def GetPVInfo(vg_name):
    """Get the free space info for PVs in a volume group.

Iustin Pop's avatar
Iustin Pop committed
306
    @param vg_name: the volume group name
Iustin Pop's avatar
Iustin Pop committed
307

Iustin Pop's avatar
Iustin Pop committed
308 309
    @rtype: list
    @return: list of tuples (free_space, name) with free_space in mebibytes
310

Iustin Pop's avatar
Iustin Pop committed
311 312 313 314 315 316
    """
    command = ["pvs", "--noheadings", "--nosuffix", "--units=m",
               "-opv_name,vg_name,pv_free,pv_attr", "--unbuffered",
               "--separator=:"]
    result = utils.RunCmd(command)
    if result.failed:
317 318
      logging.error("Can't get the PV information: %s - %s",
                    result.fail_reason, result.output)
Iustin Pop's avatar
Iustin Pop committed
319 320 321 322 323
      return None
    data = []
    for line in result.stdout.splitlines():
      fields = line.strip().split(':')
      if len(fields) != 4:
324
        logging.error("Can't parse pvs output: line '%s'", line)
Iustin Pop's avatar
Iustin Pop committed
325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342
        return None
      # skip over pvs from another vg or ones which are not allocatable
      if fields[1] != vg_name or fields[3][0] != 'a':
        continue
      data.append((float(fields[2]), fields[0]))

    return data

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

    """
    if not self.minor and not self.Attach():
      # the LV does not exist
      return True
    result = utils.RunCmd(["lvremove", "-f", "%s/%s" %
                           (self._vg_name, self._lv_name)])
    if result.failed:
343 344
      logging.error("Can't lvremove: %s - %s",
                    result.fail_reason, result.output)
Iustin Pop's avatar
Iustin Pop committed
345 346 347

    return not result.failed

Iustin Pop's avatar
Iustin Pop committed
348 349 350 351 352 353 354 355 356 357 358 359 360 361 362
  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:
      raise errors.BlockDeviceError("Failed to rename the logical volume: %s" %
                                    result.output)
363 364 365
    self._lv_name = new_name
    self.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)

Iustin Pop's avatar
Iustin Pop committed
366 367 368 369
  def Attach(self):
    """Attach to an existing LV.

    This method will try to see if an existing and active LV exists
370
    which matches our name. If so, its major/minor will be
Iustin Pop's avatar
Iustin Pop committed
371 372 373
    recorded.

    """
374
    self.attached = False
Iustin Pop's avatar
Iustin Pop committed
375 376 377
    result = utils.RunCmd(["lvs", "--noheadings", "--separator=,",
                           "-olv_attr,lv_kernel_major,lv_kernel_minor",
                           self.dev_path])
Iustin Pop's avatar
Iustin Pop committed
378
    if result.failed:
379 380
      logging.error("Can't find LV %s: %s, %s",
                    self.dev_path, result.fail_reason, result.output)
Iustin Pop's avatar
Iustin Pop committed
381
      return False
Iustin Pop's avatar
Iustin Pop committed
382 383 384
    out = result.stdout.strip().rstrip(',')
    out = out.split(",")
    if len(out) != 3:
385
      logging.error("Can't parse LVS output, len(%s) != 3", str(out))
Iustin Pop's avatar
Iustin Pop committed
386 387 388 389
      return False

    status, major, minor = out[:3]
    if len(status) != 6:
390
      logging.error("lvs lv_attr is not 6 characters (%s)", status)
Iustin Pop's avatar
Iustin Pop committed
391 392 393 394 395 396
      return False

    try:
      major = int(major)
      minor = int(minor)
    except ValueError, err:
397
      logging.error("lvs major/minor cannot be parsed: %s", str(err))
Iustin Pop's avatar
Iustin Pop committed
398 399 400 401 402

    self.major = major
    self.minor = minor
    self._degraded = status[0] == 'v' # virtual volume, i.e. doesn't backing
                                      # storage
403
    self.attached = True
Iustin Pop's avatar
Iustin Pop committed
404
    return True
Iustin Pop's avatar
Iustin Pop committed
405 406 407 408

  def Assemble(self):
    """Assemble the device.

409 410 411
    We alway run `lvchange -ay` on the LV to ensure it's active before
    use, as there were cases when xenvg was not active after boot
    (also possibly after disk issues).
Iustin Pop's avatar
Iustin Pop committed
412 413

    """
414 415
    result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
    if result.failed:
416
      logging.error("Can't activate lv %s: %s", self.dev_path, result.output)
417 418
      return False
    return self.Attach()
Iustin Pop's avatar
Iustin Pop committed
419 420 421 422 423 424 425 426 427 428

  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.

    """
    return True

429 430 431 432 433 434 435 436
  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
437 438
    case). The is_degraded parameter is the inverse of the ldisk
    parameter.
439

440 441 442 443 444
    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.
445

Iustin Pop's avatar
Iustin Pop committed
446 447
    The status was already read in Attach, so we just return it.

Iustin Pop's avatar
Iustin Pop committed
448 449 450
    @rtype: tuple
    @return: (sync_percent, estimated_time, is_degraded, ldisk)

451
    """
Iustin Pop's avatar
Iustin Pop committed
452
    return None, None, self._degraded, self._degraded
453

Iustin Pop's avatar
Iustin Pop committed
454 455 456 457 458 459
  def Open(self, force=False):
    """Make the device ready for I/O.

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

    """
460
    pass
Iustin Pop's avatar
Iustin Pop committed
461 462 463 464 465 466 467

  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.

    """
468
    pass
Iustin Pop's avatar
Iustin Pop committed
469 470 471 472 473 474 475 476 477 478 479 480 481

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

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

    # remove existing snapshot if found
    snap = LogicalVolume((self._vg_name, snap_name), None)
    snap.Remove()

    pvs_info = self.GetPVInfo(self._vg_name)
    if not pvs_info:
482 483
      raise errors.BlockDeviceError("Can't compute PV info for vg %s" %
                                    self._vg_name)
Iustin Pop's avatar
Iustin Pop committed
484 485 486 487
    pvs_info.sort()
    pvs_info.reverse()
    free_size, pv_name = pvs_info[0]
    if free_size < size:
488 489
      raise errors.BlockDeviceError("Not enough free space: required %s,"
                                    " available %s" % (size, free_size))
Iustin Pop's avatar
Iustin Pop committed
490 491 492 493

    result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-s",
                           "-n%s" % snap_name, self.dev_path])
    if result.failed:
494 495 496
      raise errors.BlockDeviceError("command: %s error: %s - %s" %
                                    (result.cmd, result.fail_reason,
                                     result.output))
Iustin Pop's avatar
Iustin Pop committed
497 498 499

    return snap_name

500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515
  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:
516 517 518
      raise errors.BlockDeviceError("Command: %s error: %s - %s" %
                                    (result.cmd, result.fail_reason,
                                     result.output))
519 520 521 522 523 524 525 526 527 528 529 530 531 532 533
  def Grow(self, amount):
    """Grow the logical volume.

    """
    # 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
    raise errors.BlockDeviceError("Can't grow LV %s: %s" %
                                  (self.dev_path, result.output))
534 535


536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585
class DRBD8Status(object):
  """A DRBD status representation class.

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

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

  def __init__(self, procline):
    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)

    self.is_standalone = self.cstatus == "StandAlone"
    self.is_wfconn = self.cstatus == "WFConnection"
    self.is_connected = self.cstatus == "Connected"
    self.is_primary = self.lrole == "Primary"
    self.is_secondary = self.lrole == "Secondary"
    self.peer_primary = self.rrole == "Primary"
    self.peer_secondary = self.rrole == "Secondary"
    self.both_primary = self.is_primary and self.peer_primary
    self.both_secondary = self.is_secondary and self.peer_secondary

    self.is_diskless = self.ldisk == "Diskless"
    self.is_disk_uptodate = self.ldisk == "UpToDate"

    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:
      self.sync_percent = None
      self.est_time = None

    self.is_sync_target = self.peer_sync_source = self.cstatus == "SyncTarget"
    self.peer_sync_target = self.is_sync_source = self.cstatus == "SyncSource"
    self.is_resync = self.is_sync_target or self.is_sync_source


586 587
class BaseDRBD(BlockDev):
  """Base DRBD class.
Iustin Pop's avatar
Iustin Pop committed
588

589 590 591
  This class contains a few bits of common functionality between the
  0.7 and 8.x versions of DRBD.

592 593 594
  """
  _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)"
                           r" \(api:(\d+)/proto:(\d+)(?:-(\d+))?\)")
Iustin Pop's avatar
Iustin Pop committed
595

596 597 598 599
  _DRBD_MAJOR = 147
  _ST_UNCONFIGURED = "Unconfigured"
  _ST_WFCONNECTION = "WFConnection"
  _ST_CONNECTED = "Connected"
Iustin Pop's avatar
Iustin Pop committed
600

601 602
  _STATUS_FILE = "/proc/drbd"

603
  @staticmethod
604
  def _GetProcData(filename=_STATUS_FILE):
605
    """Return data from /proc/drbd.
Iustin Pop's avatar
Iustin Pop committed
606 607

    """
608
    stat = open(filename, "r")
609 610 611 612 613
    try:
      data = stat.read().splitlines()
    finally:
      stat.close()
    if not data:
614
      raise errors.BlockDeviceError("Can't read any data from %s" % filename)
615
    return data
Iustin Pop's avatar
Iustin Pop committed
616

617 618 619
  @staticmethod
  def _MassageProcData(data):
    """Transform the output of _GetProdData into a nicer form.
Iustin Pop's avatar
Iustin Pop committed
620

Iustin Pop's avatar
Iustin Pop committed
621 622
    @return: a dictionary of minor: joined lines from /proc/drbd
        for that minor
Iustin Pop's avatar
Iustin Pop committed
623 624

    """
625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641
    lmatch = re.compile("^ *([0-9]+):.*$")
    results = {}
    old_minor = old_line = None
    for line in data:
      lresult = lmatch.match(line)
      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
Iustin Pop's avatar
Iustin Pop committed
642

643 644 645
  @classmethod
  def _GetVersion(cls):
    """Return the DRBD version.
Iustin Pop's avatar
Iustin Pop committed
646

647
    This will return a dict with keys:
Iustin Pop's avatar
Iustin Pop committed
648 649 650 651 652 653
      - k_major
      - k_minor
      - k_point
      - api
      - proto
      - proto2 (only on drbd > 8.2.X)
Iustin Pop's avatar
Iustin Pop committed
654 655

    """
656 657 658 659 660 661
    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)
Iustin Pop's avatar
Iustin Pop committed
662

663 664 665 666 667 668 669 670 671
    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]
Iustin Pop's avatar
Iustin Pop committed
672

673 674 675 676 677
    return retval

  @staticmethod
  def _DevPath(minor):
    """Return the path to a drbd device for a given minor.
Iustin Pop's avatar
Iustin Pop committed
678 679

    """
680
    return "/dev/drbd%d" % minor
Iustin Pop's avatar
Iustin Pop committed
681

682 683 684
  @classmethod
  def _GetUsedDevs(cls):
    """Compute the list of used DRBD devices.
Iustin Pop's avatar
Iustin Pop committed
685 686

    """
687
    data = cls._GetProcData()
Iustin Pop's avatar
Iustin Pop committed
688

689 690 691 692 693 694 695 696 697 698 699
    used_devs = {}
    valid_line = re.compile("^ *([0-9]+): cs:([^ ]+).*$")
    for line in data:
      match = valid_line.match(line)
      if not match:
        continue
      minor = int(match.group(1))
      state = match.group(2)
      if state == cls._ST_UNCONFIGURED:
        continue
      used_devs[minor] = state, line
Iustin Pop's avatar
Iustin Pop committed
700

701
    return used_devs
Iustin Pop's avatar
Iustin Pop committed
702

703 704
  def _SetFromMinor(self, minor):
    """Set our parameters based on the given minor.
705

706
    This sets our minor variable and our dev_path.
Iustin Pop's avatar
Iustin Pop committed
707 708

    """
709 710
    if minor is None:
      self.minor = self.dev_path = None
711
      self.attached = False
Iustin Pop's avatar
Iustin Pop committed
712
    else:
713 714
      self.minor = minor
      self.dev_path = self._DevPath(minor)
715
      self.attached = True
Iustin Pop's avatar
Iustin Pop committed
716 717

  @staticmethod
718 719
  def _CheckMetaSize(meta_device):
    """Check if the given meta device looks like a valid one.
Iustin Pop's avatar
Iustin Pop committed
720

721 722
    This currently only check the size, which must be around
    128MiB.
Iustin Pop's avatar
Iustin Pop committed
723 724

    """
725 726
    result = utils.RunCmd(["blockdev", "--getsize", meta_device])
    if result.failed:
727 728
      logging.error("Failed to get device size: %s - %s",
                    result.fail_reason, result.output)
729
      return False
Iustin Pop's avatar
Iustin Pop committed
730
    try:
731 732
      sectors = int(result.stdout)
    except ValueError:
733
      logging.error("Invalid output from blockdev: '%s'", result.stdout)
734 735 736
      return False
    bytes = sectors * 512
    if bytes < 128 * 1024 * 1024: # less than 128MiB
737
      logging.error("Meta device too small (%.2fMib)", (bytes / 1024 / 1024))
738 739
      return False
    if bytes > (128 + 32) * 1024 * 1024: # account for an extra (big) PE on LVM
740
      logging.error("Meta device too big (%.2fMiB)", (bytes / 1024 / 1024))
741 742
      return False
    return True
Iustin Pop's avatar
Iustin Pop committed
743

744 745
  def Rename(self, new_id):
    """Rename a device.
Iustin Pop's avatar
Iustin Pop committed
746

747
    This is not supported for drbd devices.
Iustin Pop's avatar
Iustin Pop committed
748 749

    """
750
    raise errors.ProgrammerError("Can't rename a drbd device")
Iustin Pop's avatar
Iustin Pop committed
751

Iustin Pop's avatar
Iustin Pop committed
752

753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768
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

769 770 771
  # timeout constants
  _NET_RECONFIG_TIMEOUT = 60

772
  def __init__(self, unique_id, children):
773 774
    if children and children.count(None) > 0:
      children = []
775 776
    super(DRBD8, self).__init__(unique_id, children)
    self.major = self._DRBD_MAJOR
777 778
    version = self._GetVersion()
    if version['k_major'] != 8 :
779 780
      raise errors.BlockDeviceError("Mismatch in DRBD kernel version and"
                                    " requested ganeti usage: kernel is"
781 782
                                    " %s.%s, ganeti wants 8.x" %
                                    (version['k_major'], version['k_minor']))
783

784
    if len(children) not in (0, 2):
785
      raise ValueError("Invalid configuration data %s" % str(children))
786
    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 6:
787
      raise ValueError("Invalid configuration data %s" % str(unique_id))
788 789
    (self._lhost, self._lport,
     self._rhost, self._rport,
790
     self._aminor, self._secret) = unique_id
791 792 793 794
    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,))
795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833
    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:
      raise errors.BlockDeviceError("Can't initialize meta device: %s" %
                                    result.output)

  @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()

    unused_line = re.compile("^ *([0-9]+): cs:Unconfigured$")
    used_line = re.compile("^ *([0-9]+): cs:")
    highest = None
    for line in data:
      match = unused_line.match(line)
      if match:
        return int(match.group(1))
      match = used_line.match(line)
      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:
834
      logging.error("Error: no free drbd minors!")
835 836 837 838 839 840 841 842 843 844 845 846 847 848
      raise errors.BlockDeviceError("Can't find a free DRBD minor")
    return highest + 1

  @classmethod
  def _IsValidMeta(cls, meta_device):
    """Check if the given meta device looks like a valid one.

    """
    minor = cls._FindUnusedMinor()
    minor_path = cls._DevPath(minor)
    result = utils.RunCmd(["drbdmeta", minor_path,
                           "v08", meta_device, "0",
                           "dstate"])
    if result.failed:
849
      logging.error("Invalid meta device %s: %s", meta_device, result.output)
850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868
      return False
    return True

  @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
869
    number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887

    comment = pyp.Literal ("#") + pyp.Optional(pyp.restOfLine)
    defa = pyp.Literal("_is_default").suppress()
    dbl_quote = pyp.Literal('"').suppress()

    keyword = pyp.Word(pyp.alphanums + '-')

    # value types
    value = pyp.Word(pyp.alphanums + '_-/.:')
    quoted = dbl_quote + pyp.CharsNotIn('"') + dbl_quote
    addr_port = (pyp.Word(pyp.nums + '.') + pyp.Literal(':').suppress() +
                 number)
    # meta device, extended syntax
    meta_value = ((value ^ quoted) + pyp.Literal('[').suppress() +
                  number + pyp.Word(']').suppress())

    # a statement
    stmt = (~rbrace + keyword + ~lbrace +
888
            pyp.Optional(addr_port ^ value ^ quoted ^ meta_value) +
889 890 891 892 893 894 895 896 897 898 899 900 901 902 903
            pyp.Optional(defa) + semi +
            pyp.Optional(pyp.restOfLine).suppress())

    # an entire section
    section_name = pyp.Word(pyp.alphas + '_')
    section = section_name + lbrace + pyp.ZeroOrMore(pyp.Group(stmt)) + rbrace

    bnf = pyp.ZeroOrMore(pyp.Group(section ^ stmt))
    bnf.ignore(comment)

    cls._PARSE_SHOW = bnf

    return bnf

  @classmethod
904 905
  def _GetShowData(cls, minor):
    """Return the `drbdsetup show` data for a minor.
906 907 908 909

    """
    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
    if result.failed:
910 911
      logging.error("Can't display the drbd config: %s - %s",
                    result.fail_reason, result.output)
912 913 914 915 916 917 918 919 920 921 922 923 924 925
      return None
    return result.stdout

  @classmethod
  def _GetDevInfo(cls, out):
    """Parse details about a given DRBD minor.

    This return, if available, the local backing device (as a path)
    and the local and remote (ip, port) information from a string
    containing the output of the `drbdsetup show` command as returned
    by _GetShowData.

    """
    data = {}
926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964
    if not out:
      return data

    bnf = cls._GetShowParser()
    # run pyparse

    try:
      results = bnf.parseString(out)
    except pyp.ParseException, err:
      raise errors.BlockDeviceError("Can't parse drbdsetup show output: %s" %
                                    str(err))

    # and massage the results into our desired format
    for section in results:
      sname = section[0]
      if sname == "_this_host":
        for lst in section[1:]:
          if lst[0] == "disk":
            data["local_dev"] = lst[1]
          elif lst[0] == "meta-disk":
            data["meta_dev"] = lst[1]
            data["meta_index"] = lst[2]
          elif lst[0] == "address":
            data["local_addr"] = tuple(lst[1:])
      elif sname == "_remote_host":
        for lst in section[1:]:
          if lst[0] == "address":
            data["remote_addr"] = tuple(lst[1:])
    return data

  def _MatchesLocal(self, info):
    """Test if our local config matches with an existing device.

    The parameter should be as returned from `_GetDevInfo()`. This
    method tests if our local backing device is the same as the one in
    the info parameter, in effect testing if we look like the given
    device.

    """
965 966 967 968 969
    if self._children:
      backend, meta = self._children
    else:
      backend = meta = None

970
    if backend is not None:
971
      retval = ("local_dev" in info and info["local_dev"] == backend.dev_path)
972 973
    else:
      retval = ("local_dev" not in info)
974

975
    if meta is not None:
976 977 978 979
      retval = retval and ("meta_dev" in info and
                           info["meta_dev"] == meta.dev_path)
      retval = retval and ("meta_index" in info and
                           info["meta_index"] == 0)
980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
    else:
      retval = retval and ("meta_dev" not in info and
                           "meta_index" not in info)
    return retval

  def _MatchesNet(self, info):
    """Test if our network config matches with an existing device.

    The parameter should be as returned from `_GetDevInfo()`. This
    method tests if our network configuration is the same as the one
    in the info parameter, in effect testing if we look like the given
    device.

    """
    if (((self._lhost is None and not ("local_addr" in info)) and
         (self._rhost is None and not ("remote_addr" in info)))):
      return True

    if self._lhost is None:
      return False

    if not ("local_addr" in info and
            "remote_addr" in info):
      return False

    retval = (info["local_addr"] == (self._lhost, self._lport))
    retval = (retval and
              info["remote_addr"] == (self._rhost, self._rport))
    return retval

  @classmethod
  def _AssembleLocal(cls, minor, backend, meta):
    """Configure the local part of a DRBD device.

    This is the first thing that must be done on an unconfigured DRBD
    device. And it must be done only once.

    """
    if not cls._IsValidMeta(meta):
      return False
1020 1021 1022
    args = ["drbdsetup", cls._DevPath(minor), "disk",
            backend, meta, "0", "-e", "detach", "--create-device"]
    result = utils.RunCmd(args)
1023
    if result.failed:
1024
      logging.error("Can't attach local disk: %s", result.output)
1025 1026 1027 1028 1029 1030 1031 1032 1033
    return not result.failed

  @classmethod
  def _AssembleNet(cls, minor, net_info, protocol,
                   dual_pri=False, hmac=None, secret=None):
    """Configure the network part of the device.

    """
    lhost, lport, rhost, rport = net_info
1034 1035 1036 1037 1038
    if None in net_info:
      # we don't want network connection and actually want to make
      # sure its shutdown
      return cls._ShutdownNet(minor)

1039 1040 1041 1042 1043 1044 1045 1046
    # Workaround for a race condition. When DRBD is doing its dance to
    # establish a connection with its peer, it also sends the
    # synchronization speed over the wire. In some cases setting the
    # sync speed only after setting up both sides can race with DRBD
    # connecting, hence we set it here before telling DRBD anything
    # about its peer.
    cls._SetMinorSyncSpeed(minor, constants.SYNC_SPEED)

1047
    args = ["drbdsetup", cls._DevPath(minor), "net",
1048 1049 1050
            "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport), protocol,
            "-A", "discard-zero-changes",
            "-B", "consensus",
1051
            "--create-device",
1052
            ]
1053 1054 1055 1056 1057 1058
    if dual_pri:
      args.append("-m")
    if hmac and secret:
      args.extend(["-a", hmac, "-x", secret])
    result = utils.RunCmd(args)
    if result.failed:
1059 1060
      logging.error("Can't setup network for dbrd device: %s - %s",
                    result.fail_reason, result.output)
1061 1062 1063 1064 1065
      return False

    timeout = time.time() + 10
    ok = False
    while time.time() < timeout:
1066
      info = cls._GetDevInfo(cls._GetShowData(minor))
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076
      if not "local_addr" in info or not "remote_addr" in info:
        time.sleep(1)
        continue
      if (info["local_addr"] != (lhost, lport) or
          info["remote_addr"] != (rhost, rport)):
        time.sleep(1)
        continue
      ok = True
      break
    if not ok:
1077
      logging.error("Timeout while configuring network")
1078 1079 1080
      return False
    return True

1081 1082 1083 1084 1085 1086 1087 1088
  def AddChildren(self, devices):
    """Add a disk to the DRBD device.

    """
    if self.minor is None:
      raise errors.BlockDeviceError("Can't attach to dbrd8 during AddChildren")
    if len(devices) != 2:
      raise errors.BlockDeviceError("Need two devices for AddChildren")
1089
    info = self._GetDevInfo(self._GetShowData(self.minor))
1090
    if "local_dev" in info:
1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113
      raise errors.BlockDeviceError("DRBD8 already attached to a local disk")
    backend, meta = devices
    if backend.dev_path is None or meta.dev_path is None:
      raise errors.BlockDeviceError("Children not ready during AddChildren")
    backend.Open()
    meta.Open()
    if not self._CheckMetaSize(meta.dev_path):
      raise errors.BlockDeviceError("Invalid meta device size")
    self._InitMeta(self._FindUnusedMinor(), meta.dev_path)
    if not self._IsValidMeta(meta.dev_path):
      raise errors.BlockDeviceError("Cannot initalize meta device")

    if not self._AssembleLocal(self.minor, backend.dev_path, meta.dev_path):
      raise errors.BlockDeviceError("Can't attach to local storage")
    self._children = devices

  def RemoveChildren(self, devices):
    """Detach the drbd device from local storage.

    """
    if self.minor is None:
      raise errors.BlockDeviceError("Can't attach to drbd8 during"
                                    " RemoveChildren")
1114
    # early return if we don't actually have backing storage
1115
    info = self._GetDevInfo(self._GetShowData(self.minor))
1116 1117
    if "local_dev" not in info:
      return
1118 1119 1120
    if len(self._children) != 2:
      raise errors.BlockDeviceError("We don't have two children: %s" %
                                    self._children)
1121
    if self._children.count(None) == 2: # we don't actually have children :)
1122
      logging.error("Requested detach while detached")
1123
      return
1124 1125
    if len(devices) != 2:
      raise errors.BlockDeviceError("We need two children in RemoveChildren")
1126 1127 1128 1129 1130
    for child, dev in zip(self._children, devices):
      if dev != child.dev_path:
        raise errors.BlockDeviceError("Mismatch in local storage"
                                      " (%s != %s) in RemoveChildren" %
                                      (dev, child.dev_path))
1131 1132 1133 1134 1135

    if not self._ShutdownLocal(self.minor):
      raise errors.BlockDeviceError("Can't detach from local storage")
    self._children = []

1136 1137
  @classmethod
  def _SetMinorSyncSpeed(cls, minor, kbytes):
1138 1139
    """Set the speed of the DRBD syncer.

1140 1141 1142 1143 1144 1145 1146 1147 1148
    This is the low-level implementation.

    @type minor: int
    @param minor: the drbd minor whose settings we change
    @type kbytes: int
    @param kbytes: the speed in kbytes/second
    @rtype: boolean
    @return: the success of the operation

1149
    """
1150 1151
    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "syncer",
                           "-r", "%d" % kbytes, "--create-device"])
1152
    if result.failed:
1153 1154
      logging.error("Can't change syncer rate: %s - %s",
                    result.fail_reason, result.output)
1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170
    return not result.failed

  def SetSyncSpeed(self, kbytes):
    """Set the speed of the DRBD syncer.

    @type kbytes: int
    @param kbytes: the speed in kbytes/second
    @rtype: boolean
    @return: the success of the operation

    """
    if self.minor is None:
      logging.info("Not attached during SetSyncSpeed")
      return False
    children_result = super(DRBD8, self).SetSyncSpeed(kbytes)
    return self._SetMinorSyncSpeed(self.minor, kbytes) and children_result
1171

1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183
  def GetProcStatus(self):
    """Return device data from /proc.

    """
    if self.minor is None:
      raise errors.BlockDeviceError("GetStats() called while not attached")
    proc_info = self._MassageProcData(self._GetProcData())
    if self.minor not in proc_info:
      raise errors.BlockDeviceError("Can't find myself in /proc (minor %d)" %
                                    self.minor)
    return DRBD8Status(proc_info[self.minor])

1184 1185 1186 1187 1188 1189
  def GetSyncStatus(self):
    """Returns the sync status of the device.


    If sync_percent is None, it means all is ok
    If estimated_time is None, it means we can't esimate
1190 1191 1192 1193 1194 1195 1196 1197
    the time needed, otherwise it's the time left in seconds.


    We set the is_degraded parameter to True on two conditions:
    network not connected or local disk missing.

    We compute the ldisk parameter based on wheter we have a local
    disk or not.
1198

Iustin Pop's avatar
Iustin Pop committed
1199 1200 1201
    @rtype: tuple
    @return: (sync_percent, estimated_time, is_degraded, ldisk)

1202 1203 1204
    """
    if self.minor is None and not self.Attach():
      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")
1205 1206 1207 1208
    stats = self.GetProcStatus()
    ldisk = not stats.is_disk_uptodate
    is_degraded = not stats.is_connected
    return stats.sync_percent, stats.est_time, is_degraded or ldisk, ldisk
1209 1210 1211 1212

  def Open(self, force=False):
    """Make the local state primary.

1213 1214
    If the 'force' parameter is given, the '-o' option is passed to
    drbdsetup. Since this is a potentially dangerous operation, the
1215
    force flag should be only given after creation, when it actually
1216
    is mandatory.
1217 1218 1219

    """
    if self.minor is None and not self.Attach():
1220
      logging.error("DRBD cannot attach to a device during open")