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1#!/usr/bin/env python3 

2# 

3# Copyright (C) 2020 Vates SAS - ronan.abhamon@vates.fr 

4# 

5# This program is free software: you can redistribute it and/or modify 

6# it under the terms of the GNU General Public License as published by 

7# the Free Software Foundation, either version 3 of the License, or 

8# (at your option) any later version. 

9# This program is distributed in the hope that it will be useful, 

10# but WITHOUT ANY WARRANTY; without even the implied warranty of 

11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

12# GNU General Public License for more details. 

13# 

14# You should have received a copy of the GNU General Public License 

15# along with this program. If not, see <https://www.gnu.org/licenses/>. 

16 

17from linstorjournaler import LinstorJournaler 

18from linstorvolumemanager import LinstorVolumeManager 

19import base64 

20import distutils.util 

21import errno 

22import json 

23import socket 

24import util 

25import vhdutil 

26import xs_errors 

27 

28MANAGER_PLUGIN = 'linstor-manager' 

29 

30 

31def call_remote_method(session, host_ref, method, device_path, args): 

32 try: 

33 response = session.xenapi.host.call_plugin( 

34 host_ref, MANAGER_PLUGIN, method, args 

35 ) 

36 except Exception as e: 

37 util.SMlog('call-plugin ({} with {}) exception: {}'.format( 

38 method, args, e 

39 )) 

40 raise util.SMException(str(e)) 

41 

42 util.SMlog('call-plugin ({} with {}) returned: {}'.format( 

43 method, args, response 

44 )) 

45 

46 return response 

47 

48 

49class LinstorCallException(util.SMException): 

50 def __init__(self, cmd_err): 

51 self.cmd_err = cmd_err 

52 

53 def __str__(self): 

54 return str(self.cmd_err) 

55 

56 

57class ErofsLinstorCallException(LinstorCallException): 

58 pass 

59 

60 

61class NoPathLinstorCallException(LinstorCallException): 

62 pass 

63 

64 

65def linstorhostcall(local_method, remote_method): 

66 def decorated(response_parser): 

67 def wrapper(*args, **kwargs): 

68 self = args[0] 

69 vdi_uuid = args[1] 

70 

71 device_path = self._linstor.build_device_path( 

72 self._linstor.get_volume_name(vdi_uuid) 

73 ) 

74 

75 # A. Try a call using directly the DRBD device to avoid 

76 # remote request. 

77 

78 # Try to read locally if the device is not in use or if the device 

79 # is up to date and not diskless. 

80 (node_names, in_use_by) = \ 

81 self._linstor.find_up_to_date_diskful_nodes(vdi_uuid) 

82 

83 local_e = None 

84 try: 

85 if not in_use_by or socket.gethostname() in node_names: 

86 return self._call_local_method(local_method, device_path, *args[2:], **kwargs) 

87 except ErofsLinstorCallException as e: 

88 local_e = e.cmd_err 

89 except Exception as e: 

90 local_e = e 

91 

92 util.SMlog( 

93 'unable to execute `{}` locally, retry using a readable host... (cause: {})'.format( 

94 remote_method, local_e if local_e else 'local diskless + in use or not up to date' 

95 ) 

96 ) 

97 

98 if in_use_by: 

99 node_names = {in_use_by} 

100 

101 # B. Execute the plugin on master or slave. 

102 remote_args = { 

103 'devicePath': device_path, 

104 'groupName': self._linstor.group_name 

105 } 

106 remote_args.update(**kwargs) 

107 remote_args = {str(key): str(value) for key, value in remote_args.items()} 

108 

109 try: 

110 def remote_call(): 

111 host_ref = self._get_readonly_host(vdi_uuid, device_path, node_names) 

112 return call_remote_method(self._session, host_ref, remote_method, device_path, remote_args) 

113 response = util.retry(remote_call, 5, 2) 

114 except Exception as remote_e: 

115 self._raise_openers_exception(device_path, local_e or remote_e) 

116 

117 return response_parser(self, vdi_uuid, response) 

118 return wrapper 

119 return decorated 

120 

121 

122def linstormodifier(): 

123 def decorated(func): 

124 def wrapper(*args, **kwargs): 

125 self = args[0] 

126 

127 ret = func(*args, **kwargs) 

128 self._linstor.invalidate_resource_cache() 

129 return ret 

130 return wrapper 

131 return decorated 

132 

133 

134class LinstorVhdUtil: 

135 MAX_SIZE = 2 * 1024 * 1024 * 1024 * 1024 # Max VHD size. 

136 

137 def __init__(self, session, linstor): 

138 self._session = session 

139 self._linstor = linstor 

140 

141 # -------------------------------------------------------------------------- 

142 # Getters: read locally and try on another host in case of failure. 

143 # -------------------------------------------------------------------------- 

144 

145 def check(self, vdi_uuid, ignore_missing_footer=False, fast=False): 

146 kwargs = { 

147 'ignoreMissingFooter': ignore_missing_footer, 

148 'fast': fast 

149 } 

150 return self._check(vdi_uuid, **kwargs) # pylint: disable = E1123 

151 

152 @linstorhostcall(vhdutil.check, 'check') 

153 def _check(self, vdi_uuid, response): 

154 return distutils.util.strtobool(response) 

155 

156 def get_vhd_info(self, vdi_uuid, include_parent=True): 

157 kwargs = { 

158 'includeParent': include_parent, 

159 'resolveParent': False 

160 } 

161 # TODO: Replace pylint comment with this feature when possible: 

162 # https://github.com/PyCQA/pylint/pull/2926 

163 return self._get_vhd_info(vdi_uuid, self._extract_uuid, **kwargs) # pylint: disable = E1123 

164 

165 @linstorhostcall(vhdutil.getVHDInfo, 'getVHDInfo') 

166 def _get_vhd_info(self, vdi_uuid, response): 

167 obj = json.loads(response) 

168 

169 vhd_info = vhdutil.VHDInfo(vdi_uuid) 

170 vhd_info.sizeVirt = obj['sizeVirt'] 

171 vhd_info.sizePhys = obj['sizePhys'] 

172 if 'parentPath' in obj: 

173 vhd_info.parentPath = obj['parentPath'] 

174 vhd_info.parentUuid = obj['parentUuid'] 

175 vhd_info.hidden = obj['hidden'] 

176 vhd_info.path = obj['path'] 

177 

178 return vhd_info 

179 

180 @linstorhostcall(vhdutil.hasParent, 'hasParent') 

181 def has_parent(self, vdi_uuid, response): 

182 return distutils.util.strtobool(response) 

183 

184 def get_parent(self, vdi_uuid): 

185 return self._get_parent(vdi_uuid, self._extract_uuid) 

186 

187 @linstorhostcall(vhdutil.getParent, 'getParent') 

188 def _get_parent(self, vdi_uuid, response): 

189 return response 

190 

191 @linstorhostcall(vhdutil.getSizeVirt, 'getSizeVirt') 

192 def get_size_virt(self, vdi_uuid, response): 

193 return int(response) 

194 

195 @linstorhostcall(vhdutil.getSizePhys, 'getSizePhys') 

196 def get_size_phys(self, vdi_uuid, response): 

197 return int(response) 

198 

199 @linstorhostcall(vhdutil.getDepth, 'getDepth') 

200 def get_depth(self, vdi_uuid, response): 

201 return int(response) 

202 

203 @linstorhostcall(vhdutil.getKeyHash, 'getKeyHash') 

204 def get_key_hash(self, vdi_uuid, response): 

205 return response or None 

206 

207 @linstorhostcall(vhdutil.getBlockBitmap, 'getBlockBitmap') 

208 def get_block_bitmap(self, vdi_uuid, response): 

209 return base64.b64decode(response) 

210 

211 @linstorhostcall('_get_drbd_size', 'getDrbdSize') 

212 def get_drbd_size(self, vdi_uuid, response): 

213 return int(response) 

214 

215 def _get_drbd_size(self, path): 

216 (ret, stdout, stderr) = util.doexec(['blockdev', '--getsize64', path]) 

217 if ret == 0: 

218 return int(stdout.strip()) 

219 raise util.SMException('Failed to get DRBD size: {}'.format(stderr)) 

220 

221 # -------------------------------------------------------------------------- 

222 # Setters: only used locally. 

223 # -------------------------------------------------------------------------- 

224 

225 @linstormodifier() 

226 def create(self, path, size, static, msize=0): 

227 return self._call_local_method_or_fail(vhdutil.create, path, size, static, msize) 

228 

229 @linstormodifier() 

230 def set_size_virt(self, path, size, jfile): 

231 return self._call_local_method_or_fail(vhdutil.setSizeVirt, path, size, jfile) 

232 

233 @linstormodifier() 

234 def set_size_virt_fast(self, path, size): 

235 return self._call_local_method_or_fail(vhdutil.setSizeVirtFast, path, size) 

236 

237 @linstormodifier() 

238 def set_size_phys(self, path, size, debug=True): 

239 return self._call_local_method_or_fail(vhdutil.setSizePhys, path, size, debug) 

240 

241 @linstormodifier() 

242 def set_parent(self, path, parentPath, parentRaw=False): 

243 return self._call_local_method_or_fail(vhdutil.setParent, path, parentPath, parentRaw) 

244 

245 @linstormodifier() 

246 def set_hidden(self, path, hidden=True): 

247 return self._call_local_method_or_fail(vhdutil.setHidden, path, hidden) 

248 

249 @linstormodifier() 

250 def set_key(self, path, key_hash): 

251 return self._call_local_method_or_fail(vhdutil.setKey, path, key_hash) 

252 

253 @linstormodifier() 

254 def kill_data(self, path): 

255 return self._call_local_method_or_fail(vhdutil.killData, path) 

256 

257 @linstormodifier() 

258 def snapshot(self, path, parent, parentRaw, msize=0, checkEmpty=True): 

259 return self._call_local_method_or_fail(vhdutil.snapshot, path, parent, parentRaw, msize, checkEmpty) 

260 

261 def inflate(self, journaler, vdi_uuid, vdi_path, new_size, old_size): 

262 # Only inflate if the LINSTOR volume capacity is not enough. 

263 new_size = LinstorVolumeManager.round_up_volume_size(new_size) 

264 if new_size <= old_size: 

265 return 

266 

267 util.SMlog( 

268 'Inflate {} (size={}, previous={})' 

269 .format(vdi_path, new_size, old_size) 

270 ) 

271 

272 journaler.create( 

273 LinstorJournaler.INFLATE, vdi_uuid, old_size 

274 ) 

275 self._linstor.resize_volume(vdi_uuid, new_size) 

276 

277 # TODO: Replace pylint comment with this feature when possible: 

278 # https://github.com/PyCQA/pylint/pull/2926 

279 result_size = self.get_drbd_size(vdi_uuid) # pylint: disable = E1120 

280 if result_size < new_size: 

281 util.SMlog( 

282 'WARNING: Cannot inflate volume to {}B, result size: {}B' 

283 .format(new_size, result_size) 

284 ) 

285 

286 self._zeroize(vdi_path, result_size - vhdutil.VHD_FOOTER_SIZE) 

287 self.set_size_phys(vdi_path, result_size, False) 

288 journaler.remove(LinstorJournaler.INFLATE, vdi_uuid) 

289 

290 def deflate(self, vdi_path, new_size, old_size, zeroize=False): 

291 if zeroize: 

292 assert old_size > vhdutil.VHD_FOOTER_SIZE 

293 self._zeroize(vdi_path, old_size - vhdutil.VHD_FOOTER_SIZE) 

294 

295 new_size = LinstorVolumeManager.round_up_volume_size(new_size) 

296 if new_size >= old_size: 

297 return 

298 

299 util.SMlog( 

300 'Deflate {} (new size={}, previous={})' 

301 .format(vdi_path, new_size, old_size) 

302 ) 

303 

304 self.set_size_phys(vdi_path, new_size) 

305 # TODO: Change the LINSTOR volume size using linstor.resize_volume. 

306 

307 # -------------------------------------------------------------------------- 

308 # Remote setters: write locally and try on another host in case of failure. 

309 # -------------------------------------------------------------------------- 

310 

311 @linstormodifier() 

312 def force_parent(self, path, parentPath, parentRaw=False): 

313 kwargs = { 

314 'parentPath': str(parentPath), 

315 'parentRaw': parentRaw 

316 } 

317 return self._call_method(vhdutil.setParent, 'setParent', path, use_parent=False, **kwargs) 

318 

319 @linstormodifier() 

320 def force_coalesce(self, path): 

321 return self._call_method(vhdutil.coalesce, 'coalesce', path, use_parent=True) 

322 

323 @linstormodifier() 

324 def force_repair(self, path): 

325 return self._call_method(vhdutil.repair, 'repair', path, use_parent=False) 

326 

327 @linstormodifier() 

328 def force_deflate(self, path, newSize, oldSize, zeroize): 

329 kwargs = { 

330 'newSize': newSize, 

331 'oldSize': oldSize, 

332 'zeroize': zeroize 

333 } 

334 return self._call_method('_force_deflate', 'deflate', path, use_parent=False, **kwargs) 

335 

336 def _force_deflate(self, path, newSize, oldSize, zeroize): 

337 self.deflate(path, newSize, oldSize, zeroize) 

338 

339 # -------------------------------------------------------------------------- 

340 # Static helpers. 

341 # -------------------------------------------------------------------------- 

342 

343 @classmethod 

344 def compute_volume_size(cls, virtual_size, image_type): 

345 if image_type == vhdutil.VDI_TYPE_VHD: 

346 # All LINSTOR VDIs have the metadata area preallocated for 

347 # the maximum possible virtual size (for fast online VDI.resize). 

348 meta_overhead = vhdutil.calcOverheadEmpty(cls.MAX_SIZE) 

349 bitmap_overhead = vhdutil.calcOverheadBitmap(virtual_size) 

350 virtual_size += meta_overhead + bitmap_overhead 

351 elif image_type != vhdutil.VDI_TYPE_RAW: 

352 raise Exception('Invalid image type: {}'.format(image_type)) 

353 

354 return LinstorVolumeManager.round_up_volume_size(virtual_size) 

355 

356 # -------------------------------------------------------------------------- 

357 # Helpers. 

358 # -------------------------------------------------------------------------- 

359 

360 def _extract_uuid(self, device_path): 

361 # TODO: Remove new line in the vhdutil module. Not here. 

362 return self._linstor.get_volume_uuid_from_device_path( 

363 device_path.rstrip('\n') 

364 ) 

365 

366 def _get_readonly_host(self, vdi_uuid, device_path, node_names): 

367 """ 

368 When vhd-util is called to fetch VDI info we must find a 

369 diskful DRBD disk to read the data. It's the goal of this function. 

370 Why? Because when a VHD is open in RO mode, the LVM layer is used 

371 directly to bypass DRBD verifications (we can have only one process 

372 that reads/writes to disk with DRBD devices). 

373 """ 

374 

375 if not node_names: 

376 raise xs_errors.XenError( 

377 'VDIUnavailable', 

378 opterr='Unable to find diskful node: {} (path={})' 

379 .format(vdi_uuid, device_path) 

380 ) 

381 

382 hosts = self._session.xenapi.host.get_all_records() 

383 for host_ref, host_record in hosts.items(): 

384 if host_record['hostname'] in node_names: 

385 return host_ref 

386 

387 raise xs_errors.XenError( 

388 'VDIUnavailable', 

389 opterr='Unable to find a valid host from VDI: {} (path={})' 

390 .format(vdi_uuid, device_path) 

391 ) 

392 

393 # -------------------------------------------------------------------------- 

394 

395 def _raise_openers_exception(self, device_path, e): 

396 if isinstance(e, util.CommandException): 

397 e_str = 'cmd: `{}`, code: `{}`, reason: `{}`'.format(e.cmd, e.code, e.reason) 

398 else: 

399 e_str = str(e) 

400 

401 try: 

402 volume_uuid = self._linstor.get_volume_uuid_from_device_path( 

403 device_path 

404 ) 

405 e_wrapper = Exception( 

406 e_str + ' (openers: {})'.format( 

407 self._linstor.get_volume_openers(volume_uuid) 

408 ) 

409 ) 

410 except Exception as illformed_e: 

411 e_wrapper = Exception( 

412 e_str + ' (unable to get openers: {})'.format(illformed_e) 

413 ) 

414 util.SMlog('raise opener exception: {}'.format(e_wrapper)) 

415 raise e_wrapper # pylint: disable = E0702 

416 

417 def _call_local_method(self, local_method, device_path, *args, **kwargs): 

418 if isinstance(local_method, str): 

419 local_method = getattr(self, local_method) 

420 

421 try: 

422 def local_call(): 

423 try: 

424 return local_method(device_path, *args, **kwargs) 

425 except util.CommandException as e: 

426 if e.code == errno.EROFS or e.code == errno.EMEDIUMTYPE: 

427 raise ErofsLinstorCallException(e) # Break retry calls. 

428 if e.code == errno.ENOENT: 

429 raise NoPathLinstorCallException(e) 

430 raise e 

431 # Retry only locally if it's not an EROFS exception. 

432 return util.retry(local_call, 5, 2, exceptions=[util.CommandException]) 

433 except util.CommandException as e: 

434 util.SMlog('failed to execute locally vhd-util (sys {})'.format(e.code)) 

435 raise e 

436 

437 def _call_local_method_or_fail(self, local_method, device_path, *args, **kwargs): 

438 try: 

439 return self._call_local_method(local_method, device_path, *args, **kwargs) 

440 except ErofsLinstorCallException as e: 

441 # Volume is locked on a host, find openers. 

442 self._raise_openers_exception(device_path, e.cmd_err) 

443 

444 def _call_method(self, local_method, remote_method, device_path, use_parent, *args, **kwargs): 

445 # Note: `use_parent` exists to know if the VHD parent is used by the local/remote method. 

446 # Normally in case of failure, if the parent is unused we try to execute the method on 

447 # another host using the DRBD opener list. In the other case, if the parent is required, 

448 # we must check where this last one is open instead of the child. 

449 

450 if isinstance(local_method, str): 

451 local_method = getattr(self, local_method) 

452 

453 # A. Try to write locally... 

454 try: 

455 return self._call_local_method(local_method, device_path, *args, **kwargs) 

456 except Exception: 

457 pass 

458 

459 util.SMlog('unable to execute `{}` locally, retry using a writable host...'.format(remote_method)) 

460 

461 # B. Execute the command on another host. 

462 # B.1. Get host list. 

463 try: 

464 hosts = self._session.xenapi.host.get_all_records() 

465 except Exception as e: 

466 raise xs_errors.XenError( 

467 'VDIUnavailable', 

468 opterr='Unable to get host list to run vhd-util command `{}` (path={}): {}' 

469 .format(remote_method, device_path, e) 

470 ) 

471 

472 # B.2. Prepare remote args. 

473 remote_args = { 

474 'devicePath': device_path, 

475 'groupName': self._linstor.group_name 

476 } 

477 remote_args.update(**kwargs) 

478 remote_args = {str(key): str(value) for key, value in remote_args.items()} 

479 

480 volume_uuid = self._linstor.get_volume_uuid_from_device_path( 

481 device_path 

482 ) 

483 parent_volume_uuid = None 

484 if use_parent: 

485 parent_volume_uuid = self.get_parent(volume_uuid) 

486 

487 openers_uuid = parent_volume_uuid if use_parent else volume_uuid 

488 

489 # B.3. Call! 

490 def remote_call(): 

491 try: 

492 all_openers = self._linstor.get_volume_openers(openers_uuid) 

493 except Exception as e: 

494 raise xs_errors.XenError( 

495 'VDIUnavailable', 

496 opterr='Unable to get DRBD openers to run vhd-util command `{}` (path={}): {}' 

497 .format(remote_method, device_path, e) 

498 ) 

499 

500 no_host_found = True 

501 for hostname, openers in all_openers.items(): 

502 if not openers: 

503 continue 

504 

505 try: 

506 host_ref = next(ref for ref, rec in hosts.items() if rec['hostname'] == hostname) 

507 except StopIteration: 

508 continue 

509 

510 no_host_found = False 

511 try: 

512 return call_remote_method(self._session, host_ref, remote_method, device_path, remote_args) 

513 except Exception: 

514 pass 

515 

516 if no_host_found: 

517 try: 

518 return local_method(device_path, *args, **kwargs) 

519 except Exception as e: 

520 self._raise_openers_exception(device_path, e) 

521 

522 raise xs_errors.XenError( 

523 'VDIUnavailable', 

524 opterr='No valid host found to run vhd-util command `{}` (path=`{}`, openers=`{}`)' 

525 .format(remote_method, device_path, openers) 

526 ) 

527 return util.retry(remote_call, 5, 2) 

528 

529 @staticmethod 

530 def _zeroize(path, size): 

531 if not util.zeroOut(path, size, vhdutil.VHD_FOOTER_SIZE): 

532 raise xs_errors.XenError( 

533 'EIO', 

534 opterr='Failed to zero out VHD footer {}'.format(path) 

535 )