open command fails in UBIFS when pass O_DIRECT Flag

open command fails in UBIFS when pass O_DIRECT Flag

[naveen yadav]

Hi all,

I am using UBIFS file system, and i am able to read/write.
But when i use O_DIRECT flag it fails in open command. will you pls
let me know is it issue with UBIFS.
If i use jffs2 or other file system there is no problem.

Here is my test program

#define _GNU_SOURCE
#include <stdio.h>
#include <fcntl.h>
#include <sys/stat.h>

int main()
{
int w_fd=0;
if ((w_fd = open("temp.tmp", O_RDWR | O_CREAT |O_DIRECT , 0666)) < 0)
        {

                perror("fopen");

                return 0;
        }


}

Best Regards
Naveen

Re: open command fails in UBIFS when pass O_DIRECT Flag

[Adrian Hunter]

naveen yadav wrote:
> I am using UBIFS file system, and i am able to read/write.
> But when i use O_DIRECT flag it fails in open command. will you pls
> let me know is it issue with UBIFS.

UBIFS does not support direct I/O, sorry.

Re: open command fails in UBIFS when pass O_DIRECT Flag

[Jon Fraser]

Is this planned for the future?
Is there any technical reason that prevents implementing direct IO?

Jon Fraser
Broadcom

On Wed, 2009-07-15 at 01:05 -0700, Adrian Hunter wrote:
> naveen yadav wrote:
> > I am using UBIFS file system, and i am able to read/write.
> > But when i use O_DIRECT flag it fails in open command. will you pls
> > let me know is it issue with UBIFS.
> 
> UBIFS does not support direct I/O, sorry.
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
> 

Re: open command fails in UBIFS when pass O_DIRECT Flag

[Adrian Hunter]

Jon Fraser wrote:
> Is this planned for the future?

Not at the moment.

> Is there any technical reason that prevents implementing direct IO?

Not that I can think of.  But memory mapping is probably better and
that is supported.

> 
> Jon Fraser
> Broadcom
> 
> On Wed, 2009-07-15 at 01:05 -0700, Adrian Hunter wrote:
>> naveen yadav wrote:
>>> I am using UBIFS file system, and i am able to read/write.
>>> But when i use O_DIRECT flag it fails in open command. will you pls
>>> let me know is it issue with UBIFS.
>> UBIFS does not support direct I/O, sorry.
>>
>> ______________________________________________________
>> Linux MTD discussion mailing list
>> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>>
> 
> 
>