Re: [PATCH 4.19 36/63] locking/lockdep: Add debug_locks check in __lock_downgrade()

From: Greg Kroah-Hartman
Date: Mon Sep 30 2019 - 10:08:16 EST


On Sun, Sep 29, 2019 at 11:43:38PM +0900, Tetsuo Handa wrote:
> On 2019/09/29 22:54, Greg Kroah-Hartman wrote:
> > From: Waiman Long <longman@xxxxxxxxxx>
> >
> > [ Upstream commit 513e1073d52e55b8024b4f238a48de7587c64ccf ]
> >
> > Tetsuo Handa had reported he saw an incorrect "downgrading a read lock"
> > warning right after a previous lockdep warning. It is likely that the
> > previous warning turned off lock debugging causing the lockdep to have
> > inconsistency states leading to the lock downgrade warning.
> >
> > Fix that by add a check for debug_locks at the beginning of
> > __lock_downgrade().
>
> Please drop "[PATCH 4.19 36/63] locking/lockdep: Add debug_locks check in __lock_downgrade()".
> We had a revert patch shown below in the past.

Ugh, I missed that, thanks.

> "[PATCH 4.19 37/63] locking/lockdep: Add debug_locks check in __lock_downgrade() - again" seems the correct patch.

Ok, will keep that one. And will drop the "again" part of that subject
line, had to add that to make quilt happy :(

thanks for the review.

greg k-h