挂载网络文件系统

ubuntu作为客户端，嵌入式设备作为服务端 

1、ubuntu配置

1.1、client serices 

1.2、防火墙配置

NFS端口为2049，如果没有允许可以关闭防火墙或执行sudo ufw allow nfs或sudo ufw allow 2049 

2、嵌入式设备配置 

2.1、kernel配置 

 配置kernel支持NFS(服务端和客户端，版本V2和V3)，如果设备只作为客户端可以不用配置NFS server support

 2.1.1、error: unknown field 'flush' specified in initializer

fs/nfsd/export.c:259:2: error: unknown field 'flush' specified in initializer
  .flush  = expkey_flush,
  ^
fs/nfsd/export.c:259:12: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
  .flush  = expkey_flush,
            ^~~~~~~~~~~~
fs/nfsd/export.c:259:12: note: (near initialization for 'svc_expkey_cache_template.match')
cc1: some warnings being treated as errors
  CC      fs/nfsd/nfscache.o
make[2]: *** [scripts/Makefile.build:333：fs/nfsd/export.o] 错误 1

2.1.2、error: implicit declaration of function 

fs/nfsd/filecache.c:520:18: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
  .handle_event = nfsd_file_fsnotify_handle_event,
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/nfsd/filecache.c:520:18: note: (near initialization for