Re: Msdos patch for aliased names

Alain Knaff (
Wed, 30 Jul 1997 07:21:49 +0200

>On Wed, 30 Jul 1997, Alain Knaff wrote:
>> In which way does it slow down the critical path? Is it the
>> kmalloc() in msdos_canonize that you're worried about, or is it
>> something else?
>No, I'm not worried about what happens inside the call, I'm worried about
>the testing whether we should do the call at all.

Huh? That's only one pointer comparison, in a path where we find
other similar comparisons (in permission(), in cached_lookup() for
revalidating the inode, etc...). And not to mention the loop in
lookup_dentry(), which is executed every time before we call lookup().
And if we opted for the name_translate_char solution, we would do a
"costly" pointer comparison for each _character_ of the name, instead
of once per path component.

> And what I'm more
>worried about is actually the fact that the call can change the dentry
>outside the VFS layer - something I don't like from a conceptual

Well, no dentry is changed outside the VFS layer, only a qstr which
is not yet attached to a dentry at that point. But maybe that is what
you meant?