[7.7.1] Preserve corrupted files after detecting action cache corruption. (#27601)

The logic introduced in ca183fb is too aggressive, and would also delete
files that have been renamed to *.bad after detecting corruption.

Author: tjgq

src/main/java/com/google/devtools/build/lib/actions/cache/CompactPersistentActionCache.java

@@ -268,7 +268,11 @@ private static void deleteUnrecognizedFiles(Path cacheRoot) throws IOException {
             cacheFile(cacheRoot),
             journalFile(cacheRoot),
             indexFile(cacheRoot),
-            indexJournalFile(cacheRoot));
+            indexJournalFile(cacheRoot),
+            corruptedPath(cacheFile(cacheRoot)),
+            corruptedPath(journalFile(cacheRoot)),
+            corruptedPath(indexFile(cacheRoot)),
+            corruptedPath(indexJournalFile(cacheRoot)));
     for (Path child : cacheRoot.getDirectoryEntries()) {
       if (!knownFiles.contains(child)) {
         child.delete();
@@ -314,13 +318,13 @@ private static void renameCorruptedFiles(Path cacheRoot) {
           new UnixGlob.Builder(cacheRoot, SyscallCache.NO_CACHE)
               .addPattern("action_*_v" + VERSION + ".*")
               .glob()) {
-        path.renameTo(path.getParentDirectory().getChild(path.getBaseName() + ".bad"));
+        path.renameTo(corruptedPath(path));
       }
       for (Path path :
           new UnixGlob.Builder(cacheRoot, SyscallCache.NO_CACHE)
               .addPattern("filename_*_v" + VERSION + ".*")
               .glob()) {
-        path.renameTo(path.getParentDirectory().getChild(path.getBaseName() + ".bad"));
+        path.renameTo(corruptedPath(path));
       }
     } catch (UnixGlob.BadPattern ex) {
       throw new IllegalStateException(ex); // can't happen
@@ -329,6 +333,10 @@ private static void renameCorruptedFiles(Path cacheRoot) {
     }
   }
 
+  public static Path corruptedPath(Path path) {
+    return path.getParentDirectory().getChild(path.getBaseName() + ".bad");
+  }
+
   private static final String FAILURE_PREFIX = "Failed action cache referential integrity check: ";
   /** Throws IOException if indexer contains no data or integrity check has failed. */
   private static void validateIntegrity(int indexerSize, byte[] validationRecord)

src/test/java/com/google/devtools/build/lib/actions/cache/CompactPersistentActionCacheTest.java

@@ -52,6 +52,8 @@ public class CompactPersistentActionCacheTest {
   private Path dataRoot;
   private Path mapFile;
   private Path journalFile;
+  private Path indexFile;
+  private Path indexJournalFile;
   private final ManualClock clock = new ManualClock();
   private CompactPersistentActionCache cache;
   private ArtifactRoot artifactRoot;
@@ -62,6 +64,8 @@ public final void createFiles() throws Exception  {
     cache = CompactPersistentActionCache.create(dataRoot, clock, NullEventHandler.INSTANCE);
     mapFile = CompactPersistentActionCache.cacheFile(dataRoot);
     journalFile = CompactPersistentActionCache.journalFile(dataRoot);
+    indexFile = CompactPersistentActionCache.indexFile(dataRoot);
+    indexJournalFile = CompactPersistentActionCache.indexJournalFile(dataRoot);
     artifactRoot =
         ArtifactRoot.asDerivedRoot(
             scratch.getFileSystem().getPath("/output"), ArtifactRoot.RootType.Output, "bin");
@@ -77,6 +81,21 @@ public void testDeleteUnrecognizedFiles() throws Exception {
     assertThat(unrecognizedFile.exists()).isFalse();
   }
 
+  @Test
+  public void testRenameCorruptedFiles() throws Exception {
+    FileSystemUtils.writeContentAsLatin1(mapFile, "corrupted data");
+    FileSystemUtils.writeContentAsLatin1(journalFile, "corrupted data");
+    FileSystemUtils.writeContentAsLatin1(indexFile, "corrupted data");
+    FileSystemUtils.writeContentAsLatin1(indexJournalFile, "corrupted data");
+
+    cache = CompactPersistentActionCache.create(dataRoot, clock, NullEventHandler.INSTANCE);
+
+    assertThat(CompactPersistentActionCache.corruptedPath(mapFile).exists()).isTrue();
+    assertThat(CompactPersistentActionCache.corruptedPath(journalFile).exists()).isTrue();
+    assertThat(CompactPersistentActionCache.corruptedPath(indexFile).exists()).isTrue();
+    assertThat(CompactPersistentActionCache.corruptedPath(indexJournalFile).exists()).isTrue();
+  }
+
   @Test
   public void testGetInvalidKey() {
     assertThat(cache.get("key")).isNull();