lseek more than 2GB

[rob]

I'm using a Gentoo Linux system, and I am having a problem figuring out 
lseek().  lseek() gives me an error whenever I try to position above the 
2GB mark.  I compile with "-D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE", but it 
seems like it's not taking effect.

Here's a sample program and the output:

duron bonnie++-1.02c # cat test.c
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

int main()
{
  int fd;
  off_t offs;
  int i;
  char buf[128];

  fd = open("/dev/hda",O_RDONLY);
  if ( fd < 0 )
   exit(1);

  i = 0;
  while( 1 == 1 )
  {
    offs = (off_t)lseek( fd, (off_t)(i * 1024 * 1024), SEEK_SET );
    if ( offs < (off_t)0 )
    {
      printf("died at i=%d, pos=%lld, errno=%d\n",
             i,(off_t)i*1024*1024,errno);
      exit(2);
    }
    printf("ok at i=%d,pos=%lld\n",i,(off_t)offs);
    if ( read(fd, buf,64) != 64 )
    {
      printf("read died, errno=%d\n",errno);
      exit(3);
    }
    i++;
  }

  return(0);
}
duron bonnie++-1.02c # gcc -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -o test 
test.c && ./test
<snip>
ok at i=2046,pos=2145386496
ok at i=2047,pos=2146435072
died at i=2048, pos=2147483648, errno=22
duron bonnie++-1.02c # uname -a
Linux duron 2.4.20 #4 Fri Dec 13 12:56:31 CST 2002 i686 AMD Athlon(tm) 
XP 1800+ AuthenticAMD GNU/Linux
duron bonnie++-1.02c #


The machine is running linux kernel 2.4.20, glibc 2.3.1-r2, gcc 3.2.1, 
and I got the same results on another system with vanilla 2.4.20, glibc 
2.2.5-r7 and gcc 3.2-r1.  (-r1, -r2, etc are Gentoo-build script version 
suffixes.)

I tried compiling with "gcc -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE 
-D_GNU_SOURCE -D_REENTRANT -o test test.c" with the same result.

I tried accessing a data file which is 2959788169 bytes (instead of 
/dev/hda) with the same result.

Any thoughts?