includes/filebackend/FileBackendMultiWrite.php

   1 <?php
   2 /**
   3  * Proxy backend that mirrors writes to several internal backends.
   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 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup FileBackend
  22  * @author Aaron Schulz
  23  */
  24
  25 /**
  26  * @brief Proxy backend that mirrors writes to several internal backends.
  27  *
  28  * This class defines a multi-write backend. Multiple backends can be
  29  * registered to this proxy backend and it will act as a single backend.
  30  * Use this when all access to those backends is through this proxy backend.
  31  * At least one of the backends must be declared the "master" backend.
  32  *
  33  * Only use this class when transitioning from one storage system to another.
  34  *
  35  * Read operations are only done on the 'master' backend for consistency.
  36  * Write operations are performed on all backends, in the order defined.
  37  * If an operation fails on one backend it will be rolled back from the others.
  38  *
  39  * @ingroup FileBackend
  40  * @since 1.19
  41  */
  42 class FileBackendMultiWrite extends FileBackend {
  43         /** @var Array Prioritized list of FileBackendStore objects */
  44         protected $backends = array(); // array of (backend index => backends)
  45         protected $masterIndex = -1; // integer; index of master backend
  46         protected $syncChecks = 0; // integer bitfield
  47
  48         /* Possible internal backend consistency checks */
  49         const CHECK_SIZE = 1;
  50         const CHECK_TIME = 2;
  51         const CHECK_SHA1 = 4;
  52
  53         /**
  54          * Construct a proxy backend that consists of several internal backends.
  55          * Locking, journaling, and read-only checks are handled by the proxy backend.
  56          *
  57          * Additional $config params include:
  58          *   - backends   : Array of backend config and multi-backend settings.
  59          *                  Each value is the config used in the constructor of a
  60          *                  FileBackendStore class, but with these additional settings:
  61          *                    - class         : The name of the backend class
  62          *                    - isMultiMaster : This must be set for one backend.
  63          *                    - template:     : If given a backend name, this will use
  64          *                                      the config of that backend as a template.
  65          *                                      Values specified here take precedence.
  66          *   - syncChecks : Integer bitfield of internal backend sync checks to perform.
  67          *                  Possible bits include the FileBackendMultiWrite::CHECK_* constants.
  68          *                  There are constants for SIZE, TIME, and SHA1.
  69          *                  The checks are done before allowing any file operations.
  70          * @param $config Array
  71          * @throws MWException
  72          */
  73         public function __construct( array $config ) {
  74                 parent::__construct( $config );
  75                 $this->syncChecks = isset( $config['syncChecks'] )
  76                         ? $config['syncChecks']
  77                         : self::CHECK_SIZE;
  78                 // Construct backends here rather than via registration
  79                 // to keep these backends hidden from outside the proxy.
  80                 $namesUsed = array();
  81                 foreach ( $config['backends'] as $index => $config ) {
  82                         if ( isset( $config['template'] ) ) {
  83                                 // Config is just a modified version of a registered backend's.
  84                                 // This should only be used when that config is used only by this backend.
  85                                 $config = $config + FileBackendGroup::singleton()->config( $config['template'] );
  86                         }
  87                         $name = $config['name'];
  88                         if ( isset( $namesUsed[$name] ) ) { // don't break FileOp predicates
  89                                 throw new MWException( "Two or more backends defined with the name $name." );
  90                         }
  91                         $namesUsed[$name] = 1;
  92                         // Alter certain sub-backend settings for sanity
  93                         unset( $config['readOnly'] ); // use proxy backend setting
  94                         unset( $config['fileJournal'] ); // use proxy backend journal
  95                         $config['wikiId'] = $this->wikiId; // use the proxy backend wiki ID
  96                         $config['lockManager'] = 'nullLockManager'; // lock under proxy backend
  97                         if ( !empty( $config['isMultiMaster'] ) ) {
  98                                 if ( $this->masterIndex >= 0 ) {
  99                                         throw new MWException( 'More than one master backend defined.' );
 100                                 }
 101                                 $this->masterIndex = $index; // this is the "master"
 102                                 $config['fileJournal'] = $this->fileJournal; // log under proxy backend
 103                         }
 104                         // Create sub-backend object
 105                         if ( !isset( $config['class'] ) ) {
 106                                 throw new MWException( 'No class given for a backend config.' );
 107                         }
 108                         $class = $config['class'];
 109                         $this->backends[$index] = new $class( $config );
 110                 }
 111                 if ( $this->masterIndex < 0 ) { // need backends and must have a master
 112                         throw new MWException( 'No master backend defined.' );
 113                 }
 114         }
 115
 116         /**
 117          * @see FileBackend::doOperationsInternal()
 118          * @return Status
 119          */
 120         final protected function doOperationsInternal( array $ops, array $opts ) {
 121                 $status = Status::newGood();
 122
 123                 $mbe = $this->backends[$this->masterIndex]; // convenience
 124
 125                 // Get the paths to lock from the master backend
 126                 $realOps = $this->substOpBatchPaths( $ops, $mbe );
 127                 $paths = $mbe->getPathsToLockForOpsInternal( $mbe->getOperationsInternal( $realOps ) );
 128                 // Get the paths under the proxy backend's name
 129                 $paths['sh'] = $this->unsubstPaths( $paths['sh'] );
 130                 $paths['ex'] = $this->unsubstPaths( $paths['ex'] );
 131                 // Try to lock those files for the scope of this function...
 132                 if ( empty( $opts['nonLocking'] ) ) {
 133                         // Try to lock those files for the scope of this function...
 134                         $scopeLockS = $this->getScopedFileLocks( $paths['sh'], LockManager::LOCK_UW, $status );
 135                         $scopeLockE = $this->getScopedFileLocks( $paths['ex'], LockManager::LOCK_EX, $status );
 136                         if ( !$status->isOK() ) {
 137                                 return $status; // abort
 138                         }
 139                 }
 140                 // Clear any cache entries (after locks acquired)
 141                 $this->clearCache();
 142                 // Do a consistency check to see if the backends agree
 143                 $status->merge( $this->consistencyCheck( $this->fileStoragePathsForOps( $ops ) ) );
 144                 if ( !$status->isOK() ) {
 145                         return $status; // abort
 146                 }
 147                 // Actually attempt the operation batch on the master backend...
 148                 $masterStatus = $mbe->doOperations( $realOps, $opts );
 149                 $status->merge( $masterStatus );
 150                 // Propagate the operations to the clone backends...
 151                 foreach ( $this->backends as $index => $backend ) {
 152                         if ( $index !== $this->masterIndex ) { // not done already
 153                                 $realOps = $this->substOpBatchPaths( $ops, $backend );
 154                                 $status->merge( $backend->doOperations( $realOps, $opts ) );
 155                         }
 156                 }
 157                 // Make 'success', 'successCount', and 'failCount' fields reflect
 158                 // the overall operation, rather than all the batches for each backend.
 159                 // Do this by only using success values from the master backend's batch.
 160                 $status->success = $masterStatus->success;
 161                 $status->successCount = $masterStatus->successCount;
 162                 $status->failCount = $masterStatus->failCount;
 163
 164                 return $status;
 165         }
 166
 167         /**
 168          * Check that a set of files are consistent across all internal backends
 169          *
 170          * @param $paths Array List of storage paths
 171          * @return Status
 172          */
 173         public function consistencyCheck( array $paths ) {
 174                 $status = Status::newGood();
 175                 if ( $this->syncChecks == 0 || count( $this->backends ) <= 1 ) {
 176                         return $status; // skip checks
 177                 }
 178
 179                 $mBackend = $this->backends[$this->masterIndex];
 180                 foreach ( array_unique( $paths ) as $path ) {
 181                         $params = array( 'src' => $path, 'latest' => true );
 182                         $mParams = $this->substOpPaths( $params, $mBackend );
 183                         // Stat the file on the 'master' backend
 184                         $mStat = $mBackend->getFileStat( $mParams );
 185                         if ( $this->syncChecks & self::CHECK_SHA1 ) {
 186                                 $mSha1 = $mBackend->getFileSha1Base36( $mParams );
 187                         } else {
 188                                 $mSha1 = false;
 189                         }
 190                         $mUsable = $mBackend->isPathUsableInternal( $mParams['src'] );
 191                         // Check of all clone backends agree with the master...
 192                         foreach ( $this->backends as $index => $cBackend ) {
 193                                 if ( $index === $this->masterIndex ) {
 194                                         continue; // master
 195                                 }
 196                                 $cParams = $this->substOpPaths( $params, $cBackend );
 197                                 $cStat = $cBackend->getFileStat( $cParams );
 198                                 if ( $mStat ) { // file is in master
 199                                         if ( !$cStat ) { // file should exist
 200                                                 $status->fatal( 'backend-fail-synced', $path );
 201                                                 continue;
 202                                         }
 203                                         if ( $this->syncChecks & self::CHECK_SIZE ) {
 204                                                 if ( $cStat['size'] != $mStat['size'] ) { // wrong size
 205                                                         $status->fatal( 'backend-fail-synced', $path );
 206                                                         continue;
 207                                                 }
 208                                         }
 209                                         if ( $this->syncChecks & self::CHECK_TIME ) {
 210                                                 $mTs = wfTimestamp( TS_UNIX, $mStat['mtime'] );
 211                                                 $cTs = wfTimestamp( TS_UNIX, $cStat['mtime'] );
 212                                                 if ( abs( $mTs - $cTs ) > 30 ) { // outdated file somewhere
 213                                                         $status->fatal( 'backend-fail-synced', $path );
 214                                                         continue;
 215                                                 }
 216                                         }
 217                                         if ( $this->syncChecks & self::CHECK_SHA1 ) {
 218                                                 if ( $cBackend->getFileSha1Base36( $cParams ) !== $mSha1 ) { // wrong SHA1
 219                                                         $status->fatal( 'backend-fail-synced', $path );
 220                                                         continue;
 221                                                 }
 222                                         }
 223                                 } else { // file is not in master
 224                                         if ( $cStat ) { // file should not exist
 225                                                 $status->fatal( 'backend-fail-synced', $path );
 226                                         }
 227                                 }
 228                                 if ( $mUsable !== $cBackend->isPathUsableInternal( $cParams['src'] ) ) {
 229                                         $status->fatal( 'backend-fail-synced', $path );
 230                                 }
 231                         }
 232                 }
 233
 234                 return $status;
 235         }
 236
 237         /**
 238          * Check that a set of files are consistent across all internal backends
 239          * and re-synchronize those files againt the "multi master" if needed.
 240          *
 241          * @param $paths Array List of storage paths
 242          * @return Status
 243          */
 244         public function resyncFiles( array $paths ) {
 245                 $status = Status::newGood();
 246
 247                 $mBackend = $this->backends[$this->masterIndex];
 248                 foreach ( $paths as $path ) {
 249                         $mPath  = $this->substPaths( $path, $mBackend );
 250                         $mSha1  = $mBackend->getFileSha1Base36( array( 'src' => $mPath ) );
 251                         $mExist = $mBackend->fileExists( array( 'src' => $mPath ) );
 252                         // Check of all clone backends agree with the master...
 253                         foreach ( $this->backends as $index => $cBackend ) {
 254                                 if ( $index === $this->masterIndex ) {
 255                                         continue; // master
 256                                 }
 257                                 $cPath = $this->substPaths( $path, $cBackend );
 258                                 $cSha1 = $cBackend->getFileSha1Base36( array( 'src' => $cPath ) );
 259                                 if ( $mSha1 === $cSha1 ) {
 260                                         // already synced; nothing to do
 261                                 } elseif ( $mSha1 ) { // file is in master
 262                                         $fsFile = $mBackend->getLocalReference( array( 'src' => $mPath ) );
 263                                         $status->merge( $cBackend->quickStore(
 264                                                 array( 'src' => $fsFile->getPath(), 'dst' => $cPath )
 265                                         ) );
 266                                 } elseif ( $mExist === false ) { // file is not in master
 267                                         $status->merge( $cBackend->quickDelete( array( 'src' => $cPath ) ) );
 268                                 }
 269                         }
 270                 }
 271
 272                 return $status;
 273         }
 274
 275         /**
 276          * Get a list of file storage paths to read or write for a list of operations
 277          *
 278          * @param $ops Array Same format as doOperations()
 279          * @return Array List of storage paths to files (does not include directories)
 280          */
 281         protected function fileStoragePathsForOps( array $ops ) {
 282                 $paths = array();
 283                 foreach ( $ops as $op ) {
 284                         if ( isset( $op['src'] ) ) {
 285                                 $paths[] = $op['src'];
 286                         }
 287                         if ( isset( $op['srcs'] ) ) {
 288                                 $paths = array_merge( $paths, $op['srcs'] );
 289                         }
 290                         if ( isset( $op['dst'] ) ) {
 291                                 $paths[] = $op['dst'];
 292                         }
 293                 }
 294                 return array_unique( $paths );
 295         }
 296
 297         /**
 298          * Substitute the backend name in storage path parameters
 299          * for a set of operations with that of a given internal backend.
 300          *
 301          * @param $ops Array List of file operation arrays
 302          * @param $backend FileBackendStore
 303          * @return Array
 304          */
 305         protected function substOpBatchPaths( array $ops, FileBackendStore $backend ) {
 306                 $newOps = array(); // operations
 307                 foreach ( $ops as $op ) {
 308                         $newOp = $op; // operation
 309                         foreach ( array( 'src', 'srcs', 'dst', 'dir' ) as $par ) {
 310                                 if ( isset( $newOp[$par] ) ) { // string or array
 311                                         $newOp[$par] = $this->substPaths( $newOp[$par], $backend );
 312                                 }
 313                         }
 314                         $newOps[] = $newOp;
 315                 }
 316                 return $newOps;
 317         }
 318
 319         /**
 320          * Same as substOpBatchPaths() but for a single operation
 321          *
 322          * @param $ops array File operation array
 323          * @param $backend FileBackendStore
 324          * @return Array
 325          */
 326         protected function substOpPaths( array $ops, FileBackendStore $backend ) {
 327                 $newOps = $this->substOpBatchPaths( array( $ops ), $backend );
 328                 return $newOps[0];
 329         }
 330
 331         /**
 332          * Substitute the backend of storage paths with an internal backend's name
 333          *
 334          * @param $paths Array|string List of paths or single string path
 335          * @param $backend FileBackendStore
 336          * @return Array|string
 337          */
 338         protected function substPaths( $paths, FileBackendStore $backend ) {
 339                 return preg_replace(
 340                         '!^mwstore://' . preg_quote( $this->name ) . '/!',
 341                         StringUtils::escapeRegexReplacement( "mwstore://{$backend->getName()}/" ),
 342                         $paths // string or array
 343                 );
 344         }
 345
 346         /**
 347          * Substitute the backend of internal storage paths with the proxy backend's name
 348          *
 349          * @param $paths Array|string List of paths or single string path
 350          * @return Array|string
 351          */
 352         protected function unsubstPaths( $paths ) {
 353                 return preg_replace(
 354                         '!^mwstore://([^/]+)!',
 355                         StringUtils::escapeRegexReplacement( "mwstore://{$this->name}" ),
 356                         $paths // string or array
 357                 );
 358         }
 359
 360         /**
 361          * @see FileBackend::doQuickOperationsInternal()
 362          * @return Status
 363          */
 364         protected function doQuickOperationsInternal( array $ops ) {
 365                 $status = Status::newGood();
 366                 // Do the operations on the master backend; setting Status fields...
 367                 $realOps = $this->substOpBatchPaths( $ops, $this->backends[$this->masterIndex] );
 368                 $masterStatus = $this->backends[$this->masterIndex]->doQuickOperations( $realOps );
 369                 $status->merge( $masterStatus );
 370                 // Propagate the operations to the clone backends...
 371                 foreach ( $this->backends as $index => $backend ) {
 372                         if ( $index !== $this->masterIndex ) { // not done already
 373                                 $realOps = $this->substOpBatchPaths( $ops, $backend );
 374                                 $status->merge( $backend->doQuickOperations( $realOps ) );
 375                         }
 376                 }
 377                 // Make 'success', 'successCount', and 'failCount' fields reflect
 378                 // the overall operation, rather than all the batches for each backend.
 379                 // Do this by only using success values from the master backend's batch.
 380                 $status->success = $masterStatus->success;
 381                 $status->successCount = $masterStatus->successCount;
 382                 $status->failCount = $masterStatus->failCount;
 383                 return $status;
 384         }
 385
 386         /**
 387          * @see FileBackend::doPrepare()
 388          * @return Status
 389          */
 390         protected function doPrepare( array $params ) {
 391                 $status = Status::newGood();
 392                 foreach ( $this->backends as $backend ) {
 393                         $realParams = $this->substOpPaths( $params, $backend );
 394                         $status->merge( $backend->doPrepare( $realParams ) );
 395                 }
 396                 return $status;
 397         }
 398
 399         /**
 400          * @see FileBackend::doSecure()
 401          * @param $params array
 402          * @return Status
 403          */
 404         protected function doSecure( array $params ) {
 405                 $status = Status::newGood();
 406                 foreach ( $this->backends as $backend ) {
 407                         $realParams = $this->substOpPaths( $params, $backend );
 408                         $status->merge( $backend->doSecure( $realParams ) );
 409                 }
 410                 return $status;
 411         }
 412
 413         /**
 414          * @see FileBackend::doPublish()
 415          * @param $params array
 416          * @return Status
 417          */
 418         protected function doPublish( array $params ) {
 419                 $status = Status::newGood();
 420                 foreach ( $this->backends as $backend ) {
 421                         $realParams = $this->substOpPaths( $params, $backend );
 422                         $status->merge( $backend->doPublish( $realParams ) );
 423                 }
 424                 return $status;
 425         }
 426
 427         /**
 428          * @see FileBackend::doClean()
 429          * @param $params array
 430          * @return Status
 431          */
 432         protected function doClean( array $params ) {
 433                 $status = Status::newGood();
 434                 foreach ( $this->backends as $backend ) {
 435                         $realParams = $this->substOpPaths( $params, $backend );
 436                         $status->merge( $backend->doClean( $realParams ) );
 437                 }
 438                 return $status;
 439         }
 440
 441         /**
 442          * @see FileBackend::concatenate()
 443          * @param $params array
 444          * @return Status
 445          */
 446         public function concatenate( array $params ) {
 447                 // We are writing to an FS file, so we don't need to do this per-backend
 448                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 449                 return $this->backends[$this->masterIndex]->concatenate( $realParams );
 450         }
 451
 452         /**
 453          * @see FileBackend::fileExists()
 454          * @param $params array
 455          */
 456         public function fileExists( array $params ) {
 457                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 458                 return $this->backends[$this->masterIndex]->fileExists( $realParams );
 459         }
 460
 461         /**
 462          * @see FileBackend::getFileTimestamp()
 463          * @param $params array
 464          * @return bool|string
 465          */
 466         public function getFileTimestamp( array $params ) {
 467                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 468                 return $this->backends[$this->masterIndex]->getFileTimestamp( $realParams );
 469         }
 470
 471         /**
 472          * @see FileBackend::getFileSize()
 473          * @param $params array
 474          * @return bool|int
 475          */
 476         public function getFileSize( array $params ) {
 477                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 478                 return $this->backends[$this->masterIndex]->getFileSize( $realParams );
 479         }
 480
 481         /**
 482          * @see FileBackend::getFileStat()
 483          * @param $params array
 484          * @return Array|bool|null
 485          */
 486         public function getFileStat( array $params ) {
 487                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 488                 return $this->backends[$this->masterIndex]->getFileStat( $realParams );
 489         }
 490
 491         /**
 492          * @see FileBackend::getFileContents()
 493          * @param $params array
 494          * @return bool|string
 495          */
 496         public function getFileContents( array $params ) {
 497                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 498                 return $this->backends[$this->masterIndex]->getFileContents( $realParams );
 499         }
 500
 501         /**
 502          * @see FileBackend::getFileSha1Base36()
 503          * @param $params array
 504          * @return bool|string
 505          */
 506         public function getFileSha1Base36( array $params ) {
 507                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 508                 return $this->backends[$this->masterIndex]->getFileSha1Base36( $realParams );
 509         }
 510
 511         /**
 512          * @see FileBackend::getFileProps()
 513          * @param $params array
 514          * @return Array
 515          */
 516         public function getFileProps( array $params ) {
 517                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 518                 return $this->backends[$this->masterIndex]->getFileProps( $realParams );
 519         }
 520
 521         /**
 522          * @see FileBackend::streamFile()
 523          * @param $params array
 524          * @return \Status
 525          */
 526         public function streamFile( array $params ) {
 527                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 528                 return $this->backends[$this->masterIndex]->streamFile( $realParams );
 529         }
 530
 531         /**
 532          * @see FileBackend::getLocalReference()
 533          * @param $params array
 534          * @return FSFile|null
 535          */
 536         public function getLocalReference( array $params ) {
 537                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 538                 return $this->backends[$this->masterIndex]->getLocalReference( $realParams );
 539         }
 540
 541         /**
 542          * @see FileBackend::getLocalCopy()
 543          * @param $params array
 544          * @return null|TempFSFile
 545          */
 546         public function getLocalCopy( array $params ) {
 547                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 548                 return $this->backends[$this->masterIndex]->getLocalCopy( $realParams );
 549         }
 550
 551         /**
 552          * @see FileBackend::directoryExists()
 553          * @param $params array
 554          * @return bool|null
 555          */
 556         public function directoryExists( array $params ) {
 557                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 558                 return $this->backends[$this->masterIndex]->directoryExists( $realParams );
 559         }
 560
 561         /**
 562          * @see FileBackend::getSubdirectoryList()
 563          * @param $params array
 564          * @return Array|null|Traversable
 565          */
 566         public function getDirectoryList( array $params ) {
 567                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 568                 return $this->backends[$this->masterIndex]->getDirectoryList( $realParams );
 569         }
 570
 571         /**
 572          * @see FileBackend::getFileList()
 573          * @param $params array
 574          * @return Array|null|\Traversable
 575          */
 576         public function getFileList( array $params ) {
 577                 $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
 578                 return $this->backends[$this->masterIndex]->getFileList( $realParams );
 579         }
 580
 581         /**
 582          * @see FileBackend::clearCache()
 583          */
 584         public function clearCache( array $paths = null ) {
 585                 foreach ( $this->backends as $backend ) {
 586                         $realPaths = is_array( $paths ) ? $this->substPaths( $paths, $backend ) : null;
 587                         $backend->clearCache( $realPaths );
 588                 }
 589         }
 590
 591         /**
 592          * @see FileBackend::getScopedLocksForOps()
 593          */
 594         public function getScopedLocksForOps( array $ops, Status $status ) {
 595                 $fileOps = $this->backends[$this->masterIndex]->getOperationsInternal( $ops );
 596                 // Get the paths to lock from the master backend
 597                 $paths = $this->backends[$this->masterIndex]->getPathsToLockForOpsInternal( $fileOps );
 598                 // Get the paths under the proxy backend's name
 599                 $paths['sh'] = $this->unsubstPaths( $paths['sh'] );
 600                 $paths['ex'] = $this->unsubstPaths( $paths['ex'] );
 601                 return array(
 602                         $this->getScopedFileLocks( $paths['sh'], LockManager::LOCK_UW, $status ),
 603                         $this->getScopedFileLocks( $paths['ex'], LockManager::LOCK_EX, $status )
 604                 );
 605         }
 606 }