Make base:ReplaceFile return an informative error.

third_party/leveldatabase/env_chromium.cc

 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 
 #include <errno.h>
 #include <stdio.h>
 
 #include <deque>
 
 #include "base/at_exit.h"
@@ skipping 184 matching lines @@
 namespace {
 
 class Thread;
 
 static const base::FilePath::CharType kLevelDBTestDirectoryPrefix[]
     = FILE_PATH_LITERAL("leveldb-test-");
 
 const char* PlatformFileErrorString(const ::base::PlatformFileError& error) {
   switch (error) {
     case ::base::PLATFORM_FILE_ERROR_FAILED:
-      return "Opening file failed.";
+      return "No further details.";
     case ::base::PLATFORM_FILE_ERROR_IN_USE:
       return "File currently in use.";
     case ::base::PLATFORM_FILE_ERROR_EXISTS:
       return "File already exists.";
     case ::base::PLATFORM_FILE_ERROR_NOT_FOUND:
       return "File not found.";
     case ::base::PLATFORM_FILE_ERROR_ACCESS_DENIED:
       return "Access denied.";
     case ::base::PLATFORM_FILE_ERROR_TOO_MANY_OPENED:
       return "Too many files open.";
@@ skipping 326 matching lines @@
   };
 
   virtual Status RenameFile(const std::string& src, const std::string& dst) {
     Status result;
     base::FilePath src_file_path = CreateFilePath(src);
     if (!::file_util::PathExists(src_file_path))
       return result;
     base::FilePath destination = CreateFilePath(dst);
 
     Retrier retrier(GetRetryTimeHistogram(kRenameFile), kMaxRenameTimeMillis);
+    base::PlatformFileError error = base::PLATFORM_FILE_OK;
     do {
-      if (::file_util::ReplaceFile(src_file_path, destination)) {
+      if (::file_util::ReplaceFileAndGetError(
+              src_file_path, destination, &error)) {
         sync_parent(dst);
         if (src != dst)
           sync_parent(src);
         return result;
       }
     } while (retrier.ShouldKeepTrying());
 
-    RecordErrorAt(kRenameFile);
-    return Status::IOError(src, "Could not rename file.");
+    DCHECK(error != base::PLATFORM_FILE_OK);
+    RecordOSError(kRenameFile, error);
+    char buf[100];
+    snprintf(buf, sizeof(buf), "Could not rename file: %s",
+             PlatformFileErrorString(error));
+    return Status::IOError(src, buf);
   }
 
   virtual Status LockFile(const std::string& fname, FileLock** lock) {
     *lock = NULL;
     Status result;
     int flags = ::base::PLATFORM_FILE_OPEN_ALWAYS |
                 ::base::PLATFORM_FILE_READ |
                 ::base::PLATFORM_FILE_WRITE |
                 ::base::PLATFORM_FILE_EXCLUSIVE_READ |
                 ::base::PLATFORM_FILE_EXCLUSIVE_WRITE;
@@ skipping 252 matching lines @@
 
 Env* IDBEnv() {
   return idb_env.Pointer();
 }
 
 Env* Env::Default() {
   return default_env.Pointer();
 }
 
 }