Subject: Re: possible circular locking dependency detected

From: Al Viro <[email-masked]>
Date: Fri, 2 Sep 2016 18:52:06 +0100

On Fri, Sep 02, 2016 at 10:12:08AM -0700, Linus Torvalds wrote:
> On Fri, Sep 2, 2016 at 10:02 AM, Al Viro <[email-masked]> wrote:
> >
> > It's very much _not_ just overlayfs being pathological - that it certainly is,
> > but the problem is much wider.
> 
> Al, can you take a look at my two patches, and see if you agree that
> they fix it, though?

AFAICS, they should.  Locking is obviously saner that way and AFAICS the
rest is absolutely straightforward.

Acked-by: Al Viro <[email-masked]>

> Of course, we now have *another* splice deadlock. That pipe inode is
> nasty, it's very easy to deadlock on it in subtle ways.

I'm still digging through iomap.c, but that's better taken to another branch
of this thread...