[NaCl SDK] Create Filesystem nodes in /dev/fs/...

native_client_sdk/src/libraries/nacl_io/kernel_object.cc

 // Copyright (c) 2012 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 "nacl_io/kernel_object.h"
 
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <pthread.h>
@@ skipping 22 matching lines @@
   std::string abs_path = GetAbsParts(path).Join();
 
   AUTO_LOCK(fs_lock_);
   if (filesystems_.find(abs_path) != filesystems_.end())
     return EBUSY;
 
   filesystems_[abs_path] = fs;
   return 0;
 }
 
-Error KernelObject::DetachFsAtPath(const std::string& path) {
+Error KernelObject::DetachFsAtPath(const std::string& path,
+                                   ScopedFilesystem* out_fs) {
   std::string abs_path = GetAbsParts(path).Join();
 
   AUTO_LOCK(fs_lock_);
   FsMap_t::iterator it = filesystems_.find(abs_path);
   if (filesystems_.end() == it)
     return EINVAL;
 
   // It is only legal to unmount if there are no open references
   if (it->second->RefCount() != 1)
     return EBUSY;
 
+  *out_fs = it->second;
+
   filesystems_.erase(it);
   return 0;
 }
 
 // Uses longest prefix to find the filesystem for the give path, then
 // acquires the filesystem and returns it with a relative path.
 Error KernelObject::AcquireFsAndRelPath(const std::string& path,
                                         ScopedFilesystem* out_fs,
                                         Path* rel_parts) {
   Path abs_parts = GetAbsParts(path);
@@ skipping 175 matching lines @@
   AUTO_LOCK(handle_lock_);
 
   handle_map_[fd].handle.reset(NULL);
   free_fds_.push_back(fd);
 
   // Force lower numbered FD to be available first.
   std::push_heap(free_fds_.begin(), free_fds_.end(), std::greater<int>());
 }
 
 }  // namespace nacl_io