Re: possible deadlock in ovl_copy_up_start

[Miklos Szeredi]

On Thu, Oct 18, 2018 at 8:26 AM, Amir Goldstein <amir73il@xxxxxxxxx> wrote:

> Can someone tell me what the expected behavior of a nested
> mutex_lock_interruptible(&lock); ?
>
> Why does the reproducer only warn and not really deadlock.
> It is because that is considered the lesser evil?
> and obviously, then inner unlock releases the outer lock?

No, it's not the same lock, just the same lock class (first one is
OVL_I(d_inode(old))->lock, the other is
OVL_I(d_inode(new->d_parent)))->lock).

So we could possibly get away with annotating with
mutex_lock_nested().  Is this the only place that ovl_i_lock is
nested?

Thanks,
Miklos