Re: [BUGFIX] Don't use DT_DIR: It doesn't work on non-ext* filesystems

[Christian Franke]

Pavel Roskin wrote:
> On Thu, 2009-07-23 at 11:29 +0200, Vladimir 'phcoder' Serbinenko wrote:
>
>   
> > -#ifdef DT_DIR
> > -      info.dir = (de->d_type == DT_DIR);
> > -#else
> >        info.dir = !! is_dir (path, de->d_name);
> > -#endif
> >     
>
> Fine with me.  Finally a patch that reduces the number of preprocessor
> directives :-)
>
>   

:-)

Grub hostfs has no performance requirement like e.g. find. The 
optimization with d_type can simply be ignored - patch is OK.

The idea behind d_type is that it should only be set != DT_UNKNOWN if 
the type info is available for free or at low cost. It is safe for a 
filesystem implementation to return DT_UNKNOWN always.

A correct performance-aware solution would look like:

#ifdef DT_DIR
 if (de->d_type == DT_DIR)
   info.dir = 1;
 else if (de->type == DT_FILE)
   info.dir = 0;
 else
#endif
   info.dir = !! is_dir (path, de->d_name);

This was actually wrong in my original patch (svn 1353) that was 
necessary because of missing d_type on Cygwin - Sorry! Meantime I added 
d_type support to Cygwin itself and therefore learned how this is 
supposed to work :-)

--
Regards,
Christian Franke