Re: O_DIRECT foolish question

Chris Wedgwood (cw@f00f.org)
Wed, 12 Feb 2003 15:24:43 -0800


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On Wed, Feb 12, 2003 at 06:02:58PM -0500, Bruno Diniz de Paula wrote:

> ext2.

are you able to test with another fs? (reiserfs and XFS also support
O_DIRECT)

> read(3, "", 4096) = 0

odd... I'm not sure why you get this

i tested locally here and it works as expected ... my test code is
appended.

--cw

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#define _GNU_SOURCE

#include <unistd.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>

int main()
{
int h;
int ps;
char *buf;
ssize_t n;

ps = getpagesize();
if (!(buf = valloc(ps)))
return 1;
if ((h = open("test", O_RDONLY)) < 0)
return 1;
n = read(h, buf, ps);
printf("read %d bytes\n", n);
close(h);

return 0;
}

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