maintenance/storage/checkStorage.php
<?php
/**
* Fsck for MediaWiki
*
* 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.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Maintenance ExternalStorage
*/
use MediaWiki\Permissions\UltimateAuthority;
use MediaWiki\Shell\Shell;
require_once __DIR__ . '/../Maintenance.php';
// ----------------------------------------------------------------------------------
/**
* Maintenance script to do various checks on external storage.
*
* @fixme this should extend the base Maintenance class
* @ingroup Maintenance ExternalStorage
*/
class CheckStorage extends Maintenance {
private const CONCAT_HEADER = 'O:27:"concatenatedgziphistoryblob"';
public array $oldIdMap;
public array $errors;
/** @var ExternalStoreDB */
public $dbStore = null;
public function __construct() {
parent::__construct();
$this->addOption( 'fix', 'Fix errors if possible' );
$this->addArg( 'xml', 'Path to an XML dump', false );
}
public function execute() {
$fix = $this->hasOption( 'fix' );
$xml = $this->getArg( 'xml', false );
$this->check( $fix, $xml );
}
public $errorDescriptions = [
'restore text' => 'Damaged text, need to be restored from a backup',
'restore revision' => 'Damaged revision row, need to be restored from a backup',
'unfixable' => 'Unexpected errors with no automated fixing method',
'fixed' => 'Errors already fixed',
'fixable' => 'Errors which would already be fixed if --fix was specified',
];
public function check( $fix = false, $xml = '' ) {
$dbr = $this->getReplicaDB();
if ( $fix ) {
print "Checking, will fix errors if possible...\n";
} else {
print "Checking...\n";
}
$maxRevId = $dbr->newSelectQueryBuilder()
->select( 'MAX(rev_id)' )
->from( 'revision' )
->caller( __METHOD__ )->fetchField();
$chunkSize = 1000;
$flagStats = [];
$objectStats = [];
$knownFlags = [ 'external', 'gzip', 'object', 'utf-8' ];
$this->errors = [
'restore text' => [],
'restore revision' => [],
'unfixable' => [],
'fixed' => [],
'fixable' => [],
];
for ( $chunkStart = 1; $chunkStart < $maxRevId; $chunkStart += $chunkSize ) {
$chunkEnd = $chunkStart + $chunkSize - 1;
// print "$chunkStart of $maxRevId\n";
$this->oldIdMap = [];
$dbr->ping();
// Fetch revision rows
$res = $dbr->newSelectQueryBuilder()
->select( [ 'slot_revision_id', 'content_address' ] )
->from( 'slots' )
->join( 'content', null, 'content_id = slot_content_id' )
->where( [
$dbr->expr( 'slot_revision_id', '>=', $chunkStart ),
$dbr->expr( 'slot_revision_id', '<=', $chunkEnd ),
] )
->caller( __METHOD__ )->fetchResultSet();
/** @var \MediaWiki\Storage\SqlBlobStore $blobStore */
$blobStore = $this->getServiceContainer()->getBlobStore();
'@phan-var \MediaWiki\Storage\SqlBlobStore $blobStore';
foreach ( $res as $row ) {
$textId = $blobStore->getTextIdFromAddress( $row->content_address );
if ( $textId ) {
if ( !isset( $this->oldIdMap[$textId] ) ) {
$this->oldIdMap[ $textId ] = [ $row->slot_revision_id ];
} elseif ( !in_array( $row->slot_revision_id, $this->oldIdMap[$textId] ) ) {
$this->oldIdMap[ $textId ][] = $row->slot_revision_id;
}
}
}
if ( !count( $this->oldIdMap ) ) {
continue;
}
// Fetch old_flags
$missingTextRows = $this->oldIdMap;
$externalRevs = [];
$objectRevs = [];
$res = $dbr->newSelectQueryBuilder()
->select( [ 'old_id', 'old_flags' ] )
->from( 'text' )
->where( [ 'old_id' => array_keys( $this->oldIdMap ) ] )
->caller( __METHOD__ )->fetchResultSet();
foreach ( $res as $row ) {
/**
* @var int $flags
*/
$flags = $row->old_flags;
$id = $row->old_id;
// Create flagStats row if it doesn't exist
$flagStats += [ $flags => 0 ];
// Increment counter
$flagStats[$flags]++;
// Not missing
unset( $missingTextRows[$row->old_id] );
// Check for external or object
if ( $flags == '' ) {
$flagArray = [];
} else {
$flagArray = explode( ',', $flags );
}
if ( in_array( 'external', $flagArray ) ) {
$externalRevs[] = $id;
} elseif ( in_array( 'object', $flagArray ) ) {
$objectRevs[] = $id;
}
// Check for unrecognised flags
if ( $flags == '0' ) {
// This is a known bug from 2004
// It's safe to just erase the old_flags field
if ( $fix ) {
$this->addError( 'fixed', "Warning: old_flags set to 0", $id );
$dbw = $this->getPrimaryDB();
$dbw->ping();
$dbw->newUpdateQueryBuilder()
->update( 'text' )
->set( [ 'old_flags' => '' ] )
->where( [ 'old_id' => $id ] )
->caller( __METHOD__ )
->execute();
echo "Fixed\n";
} else {
$this->addError( 'fixable', "Warning: old_flags set to 0", $id );
}
} elseif ( count( array_diff( $flagArray, $knownFlags ) ) ) {
$this->addError( 'unfixable', "Error: invalid flags field \"$flags\"", $id );
}
}
// Output errors for any missing text rows
foreach ( $missingTextRows as $oldId => $revIds ) {
$this->addError( 'restore revision', "Error: missing text row", $oldId );
}
// Verify external revisions
$externalConcatBlobs = [];
$externalNormalBlobs = [];
if ( count( $externalRevs ) ) {
$res = $dbr->newSelectQueryBuilder()
->select( [ 'old_id', 'old_flags', 'old_text' ] )
->from( 'text' )
->where( [ 'old_id' => $externalRevs ] )
->caller( __METHOD__ )->fetchResultSet();
foreach ( $res as $row ) {
$urlParts = explode( '://', $row->old_text, 2 );
if ( count( $urlParts ) !== 2 || $urlParts[1] == '' ) {
$this->addError( 'restore text', "Error: invalid URL \"{$row->old_text}\"", $row->old_id );
continue;
}
[ $proto, ] = $urlParts;
if ( $proto != 'DB' ) {
$this->addError(
'restore text',
"Error: invalid external protocol \"$proto\"",
$row->old_id );
continue;
}
$path = explode( '/', $row->old_text );
$cluster = $path[2];
$id = $path[3];
if ( isset( $path[4] ) ) {
$externalConcatBlobs[$cluster][$id][] = $row->old_id;
} else {
$externalNormalBlobs[$cluster][$id][] = $row->old_id;
}
}
}
// Check external concat blobs for the right header
$this->checkExternalConcatBlobs( $externalConcatBlobs );
// Check external normal blobs for existence
if ( count( $externalNormalBlobs ) ) {
if ( $this->dbStore === null ) {
$esFactory = $this->getServiceContainer()->getExternalStoreFactory();
$this->dbStore = $esFactory->getStore( 'DB' );
}
foreach ( $externalConcatBlobs as $cluster => $xBlobIds ) {
$blobIds = array_keys( $xBlobIds );
$extDb = $this->dbStore->getReplica( $cluster );
$blobsTable = $this->dbStore->getTable( $extDb );
$res = $extDb->newSelectQueryBuilder()
->select( [ 'blob_id' ] )
->from( $blobsTable )
->where( [ 'blob_id' => $blobIds ] )
->caller( __METHOD__ )->fetchResultSet();
foreach ( $res as $row ) {
unset( $xBlobIds[$row->blob_id] );
}
// Print errors for missing blobs rows
foreach ( $xBlobIds as $blobId => $oldId ) {
$this->addError(
'restore text',
"Error: missing target $blobId for one-part ES URL",
$oldId );
}
}
}
// Check local objects
$dbr->ping();
$concatBlobs = [];
$curIds = [];
if ( count( $objectRevs ) ) {
$headerLength = 300;
$res = $dbr->newSelectQueryBuilder()
->select( [ 'old_id', 'old_flags', "LEFT(old_text, $headerLength) AS header" ] )
->from( 'text' )
->where( [ 'old_id' => $objectRevs ] )
->caller( __METHOD__ )->fetchResultSet();
foreach ( $res as $row ) {
$oldId = $row->old_id;
$matches = [];
if ( !preg_match( '/^O:(\d+):"(\w+)"/', $row->header, $matches ) ) {
$this->addError( 'restore text', "Error: invalid object header", $oldId );
continue;
}
$className = strtolower( $matches[2] );
if ( strlen( $className ) != $matches[1] ) {
$this->addError(
'restore text',
"Error: invalid object header, wrong class name length",
$oldId
);
continue;
}
$objectStats += [ $className => 0 ];
$objectStats[$className]++;
switch ( $className ) {
case 'concatenatedgziphistoryblob':
// Good
break;
case 'historyblobstub':
case 'historyblobcurstub':
if ( strlen( $row->header ) == $headerLength ) {
$this->addError( 'unfixable', "Error: overlong stub header", $oldId );
break;
}
$stubObj = unserialize( $row->header );
if ( !is_object( $stubObj ) ) {
$this->addError( 'restore text', "Error: unable to unserialize stub object", $oldId );
break;
}
if ( $className == 'historyblobstub' ) {
$concatBlobs[$stubObj->getLocation()][] = $oldId;
} else {
$curIds[$stubObj->mCurId][] = $oldId;
}
break;
default:
$this->addError( 'unfixable', "Error: unrecognised object class \"$className\"", $oldId );
}
}
}
// Check local concat blob validity
$externalConcatBlobs = [];
if ( count( $concatBlobs ) ) {
$headerLength = 300;
$res = $dbr->newSelectQueryBuilder()
->select( [ 'old_id', 'old_flags', "LEFT(old_text, $headerLength) AS header" ] )
->from( 'text' )
->where( [ 'old_id' => array_keys( $concatBlobs ) ] )
->caller( __METHOD__ )->fetchResultSet();
foreach ( $res as $row ) {
$flags = explode( ',', $row->old_flags );
if ( in_array( 'external', $flags ) ) {
// Concat blob is in external storage?
if ( in_array( 'object', $flags ) ) {
$urlParts = explode( '/', $row->header );
if ( $urlParts[0] != 'DB:' ) {
$this->addError(
'unfixable',
"Error: unrecognised external storage type \"{$urlParts[0]}",
$row->old_id
);
} else {
$cluster = $urlParts[2];
$id = $urlParts[3];
if ( !isset( $externalConcatBlobs[$cluster][$id] ) ) {
$externalConcatBlobs[$cluster][$id] = [];
}
$externalConcatBlobs[$cluster][$id] = array_merge(
$externalConcatBlobs[$cluster][$id], $concatBlobs[$row->old_id]
);
}
} else {
$this->addError(
'unfixable',
"Error: invalid flags \"{$row->old_flags}\" on concat bulk row {$row->old_id}",
$concatBlobs[$row->old_id] );
}
} elseif ( strcasecmp(
substr( $row->header, 0, strlen( self::CONCAT_HEADER ) ),
self::CONCAT_HEADER
) ) {
$this->addError(
'restore text',
"Error: Incorrect object header for concat bulk row {$row->old_id}",
$concatBlobs[$row->old_id]
);
}
unset( $concatBlobs[$row->old_id] );
}
}
// Check targets of unresolved stubs
$this->checkExternalConcatBlobs( $externalConcatBlobs );
// next chunk
}
print "\n\nErrors:\n";
foreach ( $this->errors as $name => $errors ) {
if ( count( $errors ) ) {
$description = $this->errorDescriptions[$name];
echo "$description: " . implode( ',', array_keys( $errors ) ) . "\n";
}
}
if ( count( $this->errors['restore text'] ) && $fix ) {
if ( (string)$xml !== '' ) {
$this->restoreText( array_keys( $this->errors['restore text'] ), $xml );
} else {
echo "Can't fix text, no XML backup specified\n";
}
}
print "\nFlag statistics:\n";
$total = array_sum( $flagStats );
foreach ( $flagStats as $flag => $count ) {
printf( "%-30s %10d %5.2f%%\n", $flag, $count, $count / $total * 100 );
}
print "\nLocal object statistics:\n";
$total = array_sum( $objectStats );
foreach ( $objectStats as $className => $count ) {
printf( "%-30s %10d %5.2f%%\n", $className, $count, $count / $total * 100 );
}
}
private function addError( $type, $msg, $ids ) {
if ( is_array( $ids ) && count( $ids ) == 1 ) {
$ids = reset( $ids );
}
if ( is_array( $ids ) ) {
$revIds = [];
foreach ( $ids as $id ) {
$revIds = array_unique( array_merge( $revIds, $this->oldIdMap[$id] ) );
}
print "$msg in text rows " . implode( ', ', $ids ) .
", revisions " . implode( ', ', $revIds ) . "\n";
} else {
$id = $ids;
$revIds = $this->oldIdMap[$id];
if ( count( $revIds ) == 1 ) {
print "$msg in old_id $id, rev_id {$revIds[0]}\n";
} else {
print "$msg in old_id $id, revisions " . implode( ', ', $revIds ) . "\n";
}
}
$this->errors[$type] += array_fill_keys( $revIds, true );
}
private function checkExternalConcatBlobs( $externalConcatBlobs ) {
if ( !count( $externalConcatBlobs ) ) {
return;
}
if ( $this->dbStore === null ) {
$esFactory = $this->getServiceContainer()->getExternalStoreFactory();
$this->dbStore = $esFactory->getStore( 'DB' );
}
foreach ( $externalConcatBlobs as $cluster => $oldIds ) {
$blobIds = array_keys( $oldIds );
$extDb = $this->dbStore->getReplica( $cluster );
$blobsTable = $this->dbStore->getTable( $extDb );
$headerLength = strlen( self::CONCAT_HEADER );
$res = $extDb->newSelectQueryBuilder()
->select( [ 'blob_id', "LEFT(blob_text, $headerLength) AS header" ] )
->from( $blobsTable )
->where( [ 'blob_id' => $blobIds ] )
->caller( __METHOD__ )->fetchResultSet();
foreach ( $res as $row ) {
if ( strcasecmp( $row->header, self::CONCAT_HEADER ) ) {
$this->addError(
'restore text',
"Error: invalid header on target $cluster/{$row->blob_id} of two-part ES URL",
$oldIds[$row->blob_id]
);
}
unset( $oldIds[$row->blob_id] );
}
// Print errors for missing blobs rows
foreach ( $oldIds as $blobId => $oldIds2 ) {
$this->addError(
'restore text',
"Error: missing target $cluster/$blobId for two-part ES URL",
$oldIds2
);
}
}
}
private function restoreText( $revIds, $xml ) {
global $wgDBname;
$tmpDir = wfTempDir();
if ( !count( $revIds ) ) {
return;
}
print "Restoring text from XML backup...\n";
$revFileName = "$tmpDir/broken-revlist-$wgDBname";
$filteredXmlFileName = "$tmpDir/filtered-$wgDBname.xml";
// Write revision list
if ( !file_put_contents( $revFileName, implode( "\n", $revIds ) ) ) {
echo "Error writing revision list, can't restore text\n";
return;
}
// Run mwdumper
echo "Filtering XML dump...\n";
$exitStatus = 0;
// phpcs:ignore MediaWiki.Usage.ForbiddenFunctions.passthru
passthru( 'mwdumper ' .
Shell::escape(
"--output=file:$filteredXmlFileName",
"--filter=revlist:$revFileName",
$xml
), $exitStatus
);
if ( $exitStatus ) {
echo "mwdumper died with exit status $exitStatus\n";
return;
}
$file = fopen( $filteredXmlFileName, 'r' );
if ( !$file ) {
echo "Unable to open filtered XML file\n";
return;
}
$dbr = $this->getReplicaDB();
$dbw = $this->getPrimaryDB();
$dbr->ping();
$dbw->ping();
$source = new ImportStreamSource( $file );
$user = User::newSystemUser( User::MAINTENANCE_SCRIPT_USER, [ 'steal' => true ] );
$importer = $this->getServiceContainer()
->getWikiImporterFactory()
->getWikiImporter( $source, new UltimateAuthority( $user ) );
$importer->setRevisionCallback( [ $this, 'importRevision' ] );
$importer->setNoticeCallback( static function ( $msg, $params ) {
echo wfMessage( $msg, $params )->text() . "\n";
} );
$importer->doImport();
}
/**
* @param WikiRevision $revision
*/
public function importRevision( $revision ) {
$id = $revision->getID();
$content = $revision->getContent();
$id = $id ?: '';
if ( $content === null ) {
echo "Revision $id is broken, we have no content available\n";
return;
}
$text = $content->serialize();
if ( $text === '' ) {
// This is what happens if the revision was broken at the time the
// dump was made. Unfortunately, it also happens if the revision was
// legitimately blank, so there's no way to tell the difference. To
// be safe, we'll skip it and leave it broken
echo "Revision $id is blank in the dump, may have been broken before export\n";
return;
}
if ( !$id ) {
// No ID, can't import
echo "No id tag in revision, can't import\n";
return;
}
// Find text row again
$dbr = $this->getReplicaDB();
$res = $dbr->newSelectQueryBuilder()
->select( [ 'content_address' ] )
->from( 'slots' )
->join( 'content', null, 'content_id = slot_content_id' )
->where( [ 'slot_revision_id' => $id ] )
->caller( __METHOD__ )->fetchRow();
$blobStore = $this->getServiceContainer()
->getBlobStoreFactory()
->newSqlBlobStore();
$oldId = $blobStore->getTextIdFromAddress( $res->content_address );
if ( !$oldId ) {
echo "Missing revision row for rev_id $id\n";
return;
}
// Compress the text
$flags = $blobStore->compressData( $text );
// Update the text row
$dbw = $this->getPrimaryDB();
$dbw->newUpdateQueryBuilder()
->update( 'text' )
->set( [ 'old_flags' => $flags, 'old_text' => $text ] )
->where( [ 'old_id' => $oldId ] )
->caller( __METHOD__ )
->execute();
// Remove it from the unfixed list and add it to the fixed list
unset( $this->errors['restore text'][$id] );
$this->errors['fixed'][$id] = true;
}
}
$maintClass = CheckStorage::class;
require_once RUN_MAINTENANCE_IF_MAIN;