Revert "HBASE-27043 Let lock wait timeout to improve performance of S…

…napshotHFileCleaner (apache#4437)"

This reverts commit 4e62e84.

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/SnapshotFileCache.java

@@ -22,7 +22,6 @@
 import java.util.List;
 import java.util.Timer;
 import java.util.TimerTask;
-import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Lock;
 import org.apache.commons.lang3.ArrayUtils;
 import org.apache.hadoop.conf.Configuration;
@@ -98,8 +97,6 @@ Collection<String> filesUnderSnapshot(final FileSystem fs, final Path snapshotDi
   private ImmutableMap<String, SnapshotDirectoryInfo> snapshots = ImmutableMap.of();
   private final Timer refreshTimer;
 
-  private static final int LOCK_TIMEOUT_MS = 30000;
-
   /**
    * Create a snapshot file cache for all snapshots under the specified [root]/.snapshot on the
    * filesystem.
@@ -195,47 +192,39 @@ public Iterable<FileStatus> getUnreferencedFiles(Iterable<FileStatus> files,
     if (snapshotManager != null) {
       lock = snapshotManager.getTakingSnapshotLock().writeLock();
     }
-    try {
-      if (lock == null || lock.tryLock(LOCK_TIMEOUT_MS, TimeUnit.MILLISECONDS)) {
-        try {
-          if (snapshotManager != null && snapshotManager.isTakingAnySnapshot()) {
-            LOG.warn("Not checking unreferenced files since snapshot is running, it will "
-              + "skip to clean the HFiles this time");
-            return unReferencedFiles;
-          }
-          ImmutableSet<String> currentCache = cache;
-          for (FileStatus file : files) {
-            String fileName = file.getPath().getName();
-            if (!refreshed && !currentCache.contains(fileName)) {
-              synchronized (this) {
-                refreshCache();
-                currentCache = cache;
-                refreshed = true;
-              }
-            }
-            if (currentCache.contains(fileName)) {
-              continue;
-            }
-            if (snapshotsInProgress == null) {
-              snapshotsInProgress = getSnapshotsInProgress();
-            }
-            if (snapshotsInProgress.contains(fileName)) {
-              continue;
+    if (lock == null || lock.tryLock()) {
+      try {
+        if (snapshotManager != null && snapshotManager.isTakingAnySnapshot()) {
+          LOG.warn("Not checking unreferenced files since snapshot is running, it will "
+            + "skip to clean the HFiles this time");
+          return unReferencedFiles;
+        }
+        ImmutableSet<String> currentCache = cache;
+        for (FileStatus file : files) {
+          String fileName = file.getPath().getName();
+          if (!refreshed && !currentCache.contains(fileName)) {
+            synchronized (this) {
+              refreshCache();
+              currentCache = cache;
+              refreshed = true;
             }
-            unReferencedFiles.add(file);
           }
-        } finally {
-          if (lock != null) {
-            lock.unlock();
+          if (currentCache.contains(fileName)) {
+            continue;
+          }
+          if (snapshotsInProgress == null) {
+            snapshotsInProgress = getSnapshotsInProgress();
           }
+          if (snapshotsInProgress.contains(fileName)) {
+            continue;
+          }
+          unReferencedFiles.add(file);
+        }
+      } finally {
+        if (lock != null) {
+          lock.unlock();
         }
-      } else {
-        LOG.warn("Failed to acquire write lock on taking snapshot after waiting {}ms",
-          LOCK_TIMEOUT_MS);
       }
-    } catch (InterruptedException e) {
-      LOG.warn("Interrupted while acquiring write lock on taking snapshot");
-      Thread.currentThread().interrupt(); // restore the interrupt flag
     }
     return unReferencedFiles;
   }