linux: add UMA stat for the file system where the prefs are stored

base/file_util_linux.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/file_util.h"
+
+#include "base/file_path.h"
+
+#include <errno.h>
+#include <sys/vfs.h>
+
+namespace file_util {
+
+bool GetFileSystemType(const FilePath& path, FileSystemType* type) {
+  struct statfs statfs_buf;
+  if (statfs(path.value().c_str(), &statfs_buf) < 0) {
+    if (errno == ENOENT)
+      return false;
+    *type = FILE_SYSTEM_UNKNOWN;
+    return true;
+  }
+
+  // While you would think the possible values of f_type would be available
+  // in a header somewhere, it appears that is not the case.  These values
+  // are copied from the statfs man page.
+  switch (statfs_buf.f_type) {
+    case 0:
+      *type = FILE_SYSTEM_0;
+      break;
+    case 0xEF53:  // ext2, ext3.
+    case 0x4D44:  // dos
+    case 0x5346544E:  // NFTS
+    case 0x52654973:  // reiser
+    case 0x58465342:  // XFS
+    case 0x9123683E:  // btrfs
+    case 0x3153464A:  // JFS
+      *type = FILE_SYSTEM_ORDINARY;
+      break;
+    case 0x6969:  // NFS
+      *type = FILE_SYSTEM_NFS;
+      break;
+    case 0xFF534D42:  // CIFS
+    case 0x517B:  // SMB
+      *type = FILE_SYSTEM_SMB;
+      break;
+    case 0x73757245:  // Coda
+      *type = FILE_SYSTEM_CODA;
+      break;
+    case 0x858458f6:  // ramfs
+    case 0x01021994:  // tmpfs
+      *type = FILE_SYSTEM_MEMORY;
+      break;
+    default:
+      *type = FILE_SYSTEM_OTHER;
+  }
+  return true;
+}
+
+}  // namespace