1 files changed, 95 insertions, 0 deletions
diff --git a/lib/private/Repair/RepairInvalidShares.php b/lib/private/Repair/RepairInvalidShares.php
new file mode 100644
index 00000000000..9553f25ee70
--- /dev/null
+++ b/lib/private/Repair/RepairInvalidShares.php
@@ -0,0 +1,95 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\Repair;
+
+use OCP\IConfig;
+use OCP\IDBConnection;
+use OCP\Migration\IOutput;
+use OCP\Migration\IRepairStep;
+
+/**
+ * Repairs shares with invalid data
+ */
+class RepairInvalidShares implements IRepairStep {
+	public const CHUNK_SIZE = 200;
+
+	public function __construct(
+		protected IConfig $config,
+		protected IDBConnection $connection,
+	) {
+	}
+
+	public function getName() {
+		return 'Repair invalid shares';
+	}
+
+	/**
+	 * Adjust file share permissions
+	 */
+	private function adjustFileSharePermissions(IOutput $out) {
+		$mask = \OCP\Constants::PERMISSION_READ | \OCP\Constants::PERMISSION_UPDATE | \OCP\Constants::PERMISSION_SHARE;
+		$builder = $this->connection->getQueryBuilder();
+
+		$permsFunc = $builder->expr()->bitwiseAnd('permissions', $mask);
+		$builder
+			->update('share')
+			->set('permissions', $permsFunc)
+			->where($builder->expr()->eq('item_type', $builder->expr()->literal('file')))
+			->andWhere($builder->expr()->neq('permissions', $permsFunc));
+
+		$updatedEntries = $builder->executeStatement();
+		if ($updatedEntries > 0) {
+			$out->info('Fixed file share permissions for ' . $updatedEntries . ' shares');
+		}
+	}
+
+	/**
+	 * Remove shares where the parent share does not exist anymore
+	 */
+	private function removeSharesNonExistingParent(IOutput $out) {
+		$deletedEntries = 0;
+
+		$query = $this->connection->getQueryBuilder();
+		$query->select('s1.parent')
+			->from('share', 's1')
+			->where($query->expr()->isNotNull('s1.parent'))
+			->andWhere($query->expr()->isNull('s2.id'))
+			->leftJoin('s1', 'share', 's2', $query->expr()->eq('s1.parent', 's2.id'))
+			->groupBy('s1.parent')
+			->setMaxResults(self::CHUNK_SIZE);
+
+		$deleteQuery = $this->connection->getQueryBuilder();
+		$deleteQuery->delete('share')
+			->where($deleteQuery->expr()->eq('parent', $deleteQuery->createParameter('parent')));
+
+		$deletedInLastChunk = self::CHUNK_SIZE;
+		while ($deletedInLastChunk === self::CHUNK_SIZE) {
+			$deletedInLastChunk = 0;
+			$result = $query->executeQuery();
+			while ($row = $result->fetch()) {
+				$deletedInLastChunk++;
+				$deletedEntries += $deleteQuery->setParameter('parent', (int)$row['parent'])
+					->executeStatement();
+			}
+			$result->closeCursor();
+		}
+
+		if ($deletedEntries) {
+			$out->info('Removed ' . $deletedEntries . ' shares where the parent did not exist');
+		}
+	}
+
+	public function run(IOutput $out) {
+		$ocVersionFromBeforeUpdate = $this->config->getSystemValueString('version', '0.0.0');
+		if (version_compare($ocVersionFromBeforeUpdate, '12.0.0.11', '<')) {
+			$this->adjustFileSharePermissions($out);
+		}
+
+		$this->removeSharesNonExistingParent($out);
+	}
+}