diff --git a/lib/private/Files/Cache/FileAccess.php b/lib/private/Files/Cache/FileAccess.php
index 016ff6de46ec7..6de080e7fc704 100644
--- a/lib/private/Files/Cache/FileAccess.php
+++ b/lib/private/Files/Cache/FileAccess.php
@@ -81,11 +81,16 @@ private function rowsToEntries(array $rows): array {
 	 */
 	#[\Override]
 	public function getByFileIds(array $fileIds): array {
-		$query = $this->getQuery()->selectFileCache();
-		$query->andWhere($query->expr()->in('filecache.fileid', $query->createNamedParameter($fileIds, IQueryBuilder::PARAM_INT_ARRAY)));
-
-		$rows = $query->executeQuery()->fetchAll();
-		return $this->rowsToEntries($rows);
+		if (empty($fileIds)) {
+			return [];
+		}
+		$result = [];
+		foreach (array_chunk($fileIds, 1000) as $chunk) {
+			$query = $this->getQuery()->selectFileCache();
+			$query->andWhere($query->expr()->in('filecache.fileid', $query->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+			$result += $this->rowsToEntries($query->executeQuery()->fetchAll());
+		}
+		return $result;
 	}
 
 	/**
@@ -95,13 +100,17 @@ public function getByFileIds(array $fileIds): array {
 	 */
 	#[\Override]
 	public function getByFileIdsInStorage(array $fileIds, int $storageId): array {
-		$fileIds = array_values($fileIds);
-		$query = $this->getQuery()->selectFileCache();
-		$query->andWhere($query->expr()->in('filecache.fileid', $query->createNamedParameter($fileIds, IQueryBuilder::PARAM_INT_ARRAY)));
-		$query->andWhere($query->expr()->eq('filecache.storage', $query->createNamedParameter($storageId, IQueryBuilder::PARAM_INT)));
-
-		$rows = $query->executeQuery()->fetchAll();
-		return $this->rowsToEntries($rows);
+		if (empty($fileIds)) {
+			return [];
+		}
+		$result = [];
+		foreach (array_chunk(array_values($fileIds), 1000) as $chunk) {
+			$query = $this->getQuery()->selectFileCache();
+			$query->andWhere($query->expr()->in('filecache.fileid', $query->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+			$query->andWhere($query->expr()->eq('filecache.storage', $query->createNamedParameter($storageId, IQueryBuilder::PARAM_INT)));
+			$result += $this->rowsToEntries($query->executeQuery()->fetchAll());
+		}
+		return $result;
 	}
 
 	#[\Override]
diff --git a/lib/private/Files/SetupManager.php b/lib/private/Files/SetupManager.php
index a8c46a20bd31a..184a9fc412924 100644
--- a/lib/private/Files/SetupManager.php
+++ b/lib/private/Files/SetupManager.php
@@ -604,12 +604,7 @@ public function setupForPath(string $path, bool $includeChildren = false): void
 					array_merge(...array_values($authoritativeCachedMounts)),
 				);
 
-				$rootsMetadata = [];
-				foreach (array_chunk($rootIds, 1000) as $chunk) {
-					foreach ($this->fileAccess->getByFileIds($chunk) as $id => $fileMetadata) {
-						$rootsMetadata[$id] = $fileMetadata;
-					}
-				}
+				$rootsMetadata = $this->fileAccess->getByFileIds($rootIds);
 				$this->setupMountProviderPaths[$mountPoint] = self::SETUP_WITH_CHILDREN;
 				foreach ($authoritativeCachedMounts as $providerClass => $cachedMounts) {
 					$providerArgs = array_values(array_filter(array_map(
diff --git a/tests/lib/Files/Cache/FileAccessTest.php b/tests/lib/Files/Cache/FileAccessTest.php
index 169a07180eeca..5355a7a9baff5 100644
--- a/tests/lib/Files/Cache/FileAccessTest.php
+++ b/tests/lib/Files/Cache/FileAccessTest.php
@@ -303,6 +303,71 @@ private function setUpTestDatabaseForGetByAncestorInStorage(): void {
 			->executeStatement();
 	}
 
+	public function testGetByFileIds(): void {
+		$result = $this->fileAccess->getByFileIds([1, 2, 3]);
+
+		$this->assertCount(3, $result);
+		$this->assertArrayHasKey(1, $result);
+		$this->assertArrayHasKey(2, $result);
+		$this->assertArrayHasKey(3, $result);
+	}
+
+	public function testGetByFileIdsWithEmptyArray(): void {
+		$result = $this->fileAccess->getByFileIds([]);
+		$this->assertCount(0, $result);
+	}
+
+	public function testGetByFileIdsWithNonExistentIds(): void {
+		$result = $this->fileAccess->getByFileIds([9998, 9999]);
+		$this->assertCount(0, $result);
+	}
+
+	public function testGetByFileIdsSpanningChunkBoundary(): void {
+		// 1001 IDs exceeds Oracle's 1000-element IN limit — verifies chunked queries return correct results
+		$ids = range(1, 1001);
+		$result = $this->fileAccess->getByFileIds($ids);
+
+		// Only fileids 1–7 exist in the test data
+		$this->assertCount(7, $result);
+		foreach (range(1, 7) as $id) {
+			$this->assertArrayHasKey($id, $result);
+		}
+	}
+
+	public function testGetByFileIdsInStorage(): void {
+		$result = $this->fileAccess->getByFileIdsInStorage([1, 2, 3], 1);
+
+		$this->assertCount(3, $result);
+		$this->assertArrayHasKey(1, $result);
+		$this->assertArrayHasKey(2, $result);
+		$this->assertArrayHasKey(3, $result);
+	}
+
+	public function testGetByFileIdsInStorageFiltersStorage(): void {
+		// fileids 6 and 7 belong to storage 2, not storage 1
+		$result = $this->fileAccess->getByFileIdsInStorage([1, 6, 7], 1);
+
+		$this->assertCount(1, $result);
+		$this->assertArrayHasKey(1, $result);
+	}
+
+	public function testGetByFileIdsInStorageWithEmptyArray(): void {
+		$result = $this->fileAccess->getByFileIdsInStorage([], 1);
+		$this->assertCount(0, $result);
+	}
+
+	public function testGetByFileIdsInStorageSpanningChunkBoundary(): void {
+		// 1001 IDs exceeds Oracle's 1000-element IN limit — verifies chunked queries return correct results
+		$ids = range(1, 1001);
+		$result = $this->fileAccess->getByFileIdsInStorage($ids, 1);
+
+		// fileids 1–5 are in storage 1; 6 and 7 are in storage 2
+		$this->assertCount(5, $result);
+		foreach (range(1, 5) as $id) {
+			$this->assertArrayHasKey($id, $result);
+		}
+	}
+
 	/**
 	 * Test fetching files by ancestor in storage.
 	 */