Re: [PATCH net 1/2] vhost: use mutex_lock_nested() in vhost_dev_lock_vqs()

From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Wed, 24 Jan 2018 23:46:19 +0200

On Wed, Jan 24, 2018 at 04:38:30PM -0500, David Miller wrote:

quoted

From: Jason Wang <redacted>
Date: Tue, 23 Jan 2018 17:27:25 +0800

quoted

We used to call mutex_lock() in vhost_dev_lock_vqs() which tries to
hold mutexes of all virtqueues. This may confuse lockdep to report a
possible deadlock because of trying to hold locks belong to same
class. Switch to use mutex_lock_nested() to avoid false positive.

Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
Reported-by: syzbot+dbb7c1161485e61b0241@syzkaller.appspotmail.com
Signed-off-by: Jason Wang <redacted>

Michael, I see you ACK'd this, meaning that you're OK with these two
fixes going via my net tree?

Thanks.

Yes - this seems to be what Jason wanted (judging by the net
tag in the subject) and I'm fine with it.
Thanks a lot.

Great, not a problem, done.