Re: [PATCH v5 0/6] fs/dcache: Track & limit # of negative dentries

[Linus Torvalds]

On Sat, Jul 14, 2018 at 10:35 AM Pavel Machek <pavel@xxxxxx> wrote:
>
> Could we allocate -ve entries from separate slab?

No, because negative dentrires don't stay negative.

Every single positive dentry starts out as a negative dentry that is
passed in to "lookup()" to maybe be made positive.

And most of the time they <i>do</i> turn positive, because most of the
time people actually open files that exist.

But then occasionally you don't, because you're just blindly opening a
filename whether it exists or not (to _check_ whether it's there).

              Linus