branch-2.0.4-alpha/hadoop-hdfs-project/hadoop-hdfs/src/main/native/fuse-dfs/fuse_impls_release.c

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "fuse_dfs.h"
#include "fuse_impls.h"
#include "fuse_file_handle.h"
#include "fuse_connect.h"

#include <stdlib.h>

/**
 * release a fuse_file_info structure.
 *
 * When this function is invoked, there are no more references to our
 * fuse_file_info structure that exist anywhere.  So there is no need for
 * locking to protect this structure here.
 *
 * Another thread could open() the same file, and get a separate, different file
 * descriptor with a different, separate fuse_file_info structure.  In HDFS,
 * this results in one writer winning and overwriting everything the other
 * writer has done.
 */

int dfs_release (const char *path, struct fuse_file_info *fi) {
  TRACE1("release", path)

  // retrieve dfs specific data
  dfs_context *dfs = (dfs_context*)fuse_get_context()->private_data;

  // check params and the context var
  assert(path);
  assert(dfs);
  assert('/' == *path);

  int ret = 0;
  dfs_fh *fh = (dfs_fh*)fi->fh;
  assert(fh);
  hdfsFile file_handle = (hdfsFile)fh->hdfsFH;
  if (NULL != file_handle) {
    if (hdfsCloseFile(hdfsConnGetFs(fh->conn), file_handle) != 0) {
      ERROR("Could not close handle %ld for %s\n",(long)file_handle, path);
      ret = -EIO;
    }
  }
  free(fh->buf);
  hdfsConnRelease(fh->conn);
  pthread_mutex_destroy(&fh->mutex);
  free(fh);
  fi->fh = 0;
  return ret;
}