Re: silent semantic changes with reiser4

Linus Torvalds
2004-08-26T18:55:07Z

On Thu, 26 Aug 2004, Rik van Riel wrote:
>
> So you'd have both a file and a directory that just happen
> to have the same name ? How would this work in the dcache?

There would be only one entry in the dcache. The lookup will select
whether it opens the file or the directory based on O_DIRECTORY (and
usage, of course - if it's in the middle of a path, it obviously needs to
be opened as a directory regardless).

That's not the problem. The problem from a dcache standpoint ends up being
when the file has a link, and you have two paths to the same sub-file
through two different ways:

.. create file 'x' with named stream 'y' ...
ln x z
ls -l x/y z/y /* it's the same attribute!! */

but this is actually exactly the same thing that we already have with
mounts, ie it is equivalent (from a dentry standpoint) to

.. create directory 'x' with file 'y' ..
mkdir z
mount --bind x z
ls -l x/y z/y /* It's the same file!! */

so none of this is really anything "new" from a dcache standpoint.

Except for all the details, of course ;)

Linus