Re: [PATCH v12 10/12] namei: aggressively check for nd->root escape on ".." resolution

[Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>]

On Wed, Sep 4, 2019 at 2:35 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Sep 4, 2019 at 2:09 PM Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > So you'd have three stages:
> >
> >  1) ".." always returns -EXDEV
> >
> >  2) ".." returns -EXDEV if there was a concurrent rename/mount
> >
> >  3) ".." returns -EXDEV if there was a concurrent rename/mount and we
> > reset the sequence numbers and check if you escaped.
>
> In fact, I wonder if this should return -EAGAIN instead - to say that
> "retrying may work".

And here "this" was meant to be "case 2" - I was moving the quoted
text around and didn't fix my wording, so now it is ambiguous or
implies #3, which would be crazy.

Sorry for the confusion,

            Linus