O_DIRECT buglet

[Lennert Buytenhek <buytenh@xxxxxxx>]

(Not on the list, please CC on replies)

Hi,

Doing O_DIRECT I/O to a buffer which is not on an appropriate block boundary
seem to fail with return code 22 instead of -22 (EINVAL). This is on 2.4.2
with an XFS tree checkout from 20010329.


tia,
Lennert


-- test.c
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#define O_DIRECT         040000 /* direct disk access hint */

int main()
{
        char buf[16384];
        int fd;
        char *p;

        p = (char *)((((unsigned long)buf) + 8191) & ~8191L);
        fd = open("blah", O_CREAT | O_RDWR | O_DIRECT);

        printf("write returns %i\n", write(fd, buf, 8192));
        printf("write returns %i\n", write(fd, p, 1));

        return 0;
}
-- actual output
[buytenh@mara test]$ ./test
write returns 22
write returns 22