[Samba] Does samba support fsync() a directory?

[曹树烽]

Hi group:
     I need some help!
     I use samba 4.5.8
     And I mount a samba directory from CentOS 7.

     When I run such program in the mounted directory:
```

#include  <stdlib.h>
#include  <stdio.h>
#include  <errno.h>
#include  <fcntl.h>
#include  <string.h>
int  main()  {
	printf("open aaa\n");
  	int  fd  =  open("aaa",  O_RDONLY  |  O_DIRECTORY,  0);
  	if  (fd  <  0)  {
  	perror("open aaa");
   	}
   	printf("sync aaa\n");
   	if(fsync(fd))  {
   	perror("sync aaa");
   	}
   	printf("OK\n");
   	return  0;
}

```
	I get such error: `sync aaa: Invalid argument`
	Is this expected for samba?
	Thanks in advance!

Best Regards
Cao