Re: O_CREAT|O_DIRECTORY on nonexisting file with ext4 not posix-compliant

[NeilBrown <neilb@suse.de>]

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On Mon, 15 Dec 2014 17:39:09 +0000 Fiedler Roman <Roman.Fiedler@ait.ac.at>
wrote:

> Hi,
> 
> It seems that the open syscall is not POSIX-compliant when using both
> O_CREAT|O_DIRECTORY. This was discussed in [1] with a reference to the POSIX
> documentation.

Given that O_DIRECTORY is not part of POSIX, I don't think that
POSIX-compliance is an issue here.

However the implementation does seem to differ from the Linux documentation.

I suggest you submit a patch to the manpages project to change

  If  pathname  is  not a directory

to

  If  pathname exists and is  not a directory

That should fix the problem.

NeilBrown


> 
> A simple test program is:
> 
> #include <fcntl.h>
> #include <stdio.h>
> #include <sys/stat.h>
> 
> int main(int argc, char **argv) {
>   int fd;
>   struct stat statBuf;
>   int result;
> 
>   fd=open("xxx", O_RDWR|O_CREAT|O_DIRECTORY, 0600);
>   result=fstat(fd, &statBuf);
>   if(result) {
>     fprintf(stderr, "Stat failed\n");
>     return(1);
>   }
>   fprintf(stderr, "New element type is %d\n", S_ISDIR(statBuf.st_mode));
>   return(0);
> }
> 
> 
> Kind Regards,
> Roman
> 
> [1] http://www.openwall.com/lists/oss-security/2014/11/26/10
> 
> 
> DI Roman Fiedler
> Scientist
> Digital Safety & Security Department
> Assistive Healthcare Information Technology
> 
> AIT Austrian Institute of Technology GmbH
> Reininghausstraße 13/1 | 8020 Graz | Austria
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> 
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> 


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