Created attachment 389979 [details]
test.c

Description of problem:

fallocate() syscall always fails with EOPNOTSUPP on ext4 with x86_64 arch

Version-Release number of selected component (if applicable):
kernel-2.6.18-164.11.1.el5.x86_64
kernel-2.6.18-186.el5.x86_64

How reproducible:
Always.

Steps to Reproduce:
1. vi test.c:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <fcntl.h>
#include <unistd.h>

#include <asm/unistd.h>

int fallocate(int fd, int mode, loff_t offset, loff_t len)
{
        return syscall(__NR_fallocate, fd, mode, offset, len);
}

int main()
{
        int fd = open("test.dat", O_RDWR | O_CREAT, 0666);
        if (fd == -1) {
                perror("open");
                return 1;
        }
        if (fallocate(fd, 0, 0, 1048576)) {
                perror("fallocate");
        }
        close(fd);
        return 0;
}

2. gcc -Wall -o test test.c
3. ./test
  
Actual results:
fallocate: Operation not supported

Expected results:
test.dat file 1MB length

Additional info:
tried the same kernels but i686 arch: work as expected