[Samba] open(2) O_DIRECT on smbmount gives EINVAL

[tupple]

Does samba 3.0.23c not support the use of O_DIRECT?  When I try to open an 
smbmount'd file using O_DIRECT, I get EINVAL.  I am able to use O_DIRECT with no 
problems on a block device and nfs mounts, so I know the kernel supports it.

samba:  3.0.23c
kernel: 2.6.9-42.0.3.EL (32-bit)

I am using the below code for my test.  smb fails on open(2).

#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdint.h>

#define SECTORSIZE 512

#define ALIGN_NUM(val, mult) (((val) + ((mult) - 1)) & ~(((mult) - 1)))
#define ALIGN_PTR(ptr, mult) (void *)ALIGN_NUM((uintptr_t)(ptr), mult)

#define DECL_ALIGNED_BUFFER(name, size) \
   char __##name[(size) + SECTORSIZE]; \
   char *name = (char *)ALIGN_PTR(__##name, SECTORSIZE)

#define TEST_FILE "test.txt"

int main(void)
{
   int fd;
   int len = SECTORSIZE;
   DECL_ALIGNED_BUFFER(buf, len);

   unlink(TEST_FILE);
   errno = 0;

   // smb fails here
   fd = open(TEST_FILE, O_WRONLY|O_CREAT|O_EXCL|O_DIRECT, 0777);
   if(fd == -1)
   {
     perror("open");
     return 1;
   }

   memset(buf, ' ', len);
   memcpy(buf, "hello\n", 6);

   if(write(fd, buf, len) == -1)
   {
     perror("write");
     close(fd);
     return 1;
   }

   close(fd);
   printf("success\n");
   return 0;
}


thanks