文件名称：FUSE相关知识-HDFS测试报告
文件大小：1.37MB
文件格式：PPT
更新时间：2024-05-12 13:31:19
hdfs hbase
FUSE相关知识 FUSE（用户空间文件系统）允许非特权用户创建功能完备的文件系统，而不需要重新编译内核。对于读写虚拟文件系统来说，FUSE是个很好的选择。int (*access) (const char *, int); int (*chmod) (const char *, mode_t); int (*chown) (const char *, uid_t, gid_t); int (*flush) (const char *, struct fuse_file_info *); int (*getattr) (const char *, struct stat *); int (*mkdir) (const char *, mode_t); int (*mknod) (const char *, mode_t, dev_t); int (*unlink) (const char *); int (*truncate) (const char *, off_t); int (*open) (const char *, struct fuse_file_info *); int (*read) (const char *, char *, size_t, off_t, struct fuse_file_info *); int (*write) (const char *, const char *, size_t, off_t, struct fuse_file_info *); /** * 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_connect.h" #include "fuse_file_handle.h" int dfs_open(const char *path, struct fuse_file_info *fi) { TRACE1("open", path) dfs_context *dfs = (dfs_context*)fuse_get_context()->private_data; // check params and the context var assert(path); assert('/' == *path); assert(dfs); int ret = 0; // 0x8000 is always passed in and hadoop doesn't like it, so killing it here // bugbug figure out what this flag is and report problem to Hadoop JIRA int flags = (fi->flags & 0x7FFF); // retrieve dfs specific data dfs_fh *fh = (dfs_fh*)malloc(sizeof (dfs_fh)); if (fh == NULL) { syslog(LOG_ERR, "ERROR: malloc of new file handle failed %s:%d\n", __FILE__, __LINE__); return -EIO; } if ((fh->fs = doConnectAsUser(dfs->nn_hostname,dfs->nn_port)) == NULL) { syslog(LOG_ERR, "ERROR: could not connect to dfs %s:%d\n", __FILE__, __LINE__); return -EIO; } if ((fh->hdfsFH = hdfsOpenFile(fh->fs, path, flags, 0, 3, 0)) == NULL) { syslog(LOG_ERR, "ERROR: could not connect open file %s:%d\n", __FILE__, __LINE__); return -EIO; } // // mutex needed for reads/writes // pthread_mutex_init(&fh->mutex, NULL); if (fi->flags & O_WRONLY || fi->flags & O_CREAT) { // write specific initialization fh->buf = NULL; } else { // read specific initialization assert(dfs->rdbuffer_size > 0); if (NULL == (fh->buf = (char*)malloc(dfs->rdbuffer_size*sizeof (char)))) { syslog(LOG_ERR, "ERROR: could not allocate memory for file buffer for a read for file %s dfs %s:%d\n", path,__FILE__, __LINE__); ret = -EIO; } fh->buffersStartOffset = 0; fh->bufferSize = 0; } fi->fh = (uint64_t)fh; return ret; } *