Re: [PATCH] Revert "workqueue: re-add lockdep dependencies for flushing"

From: Sagi Grimberg
Date: Mon Oct 22 2018 - 20:43:57 EST



I must also say that I'm disappointed you'd try to do things this way.
I'd be (have been?) willing to actually help you understand the problem
and add the annotations, but rather than answer my question ("where do I
find the right git tree"!) you just send a revert patch.

Sorry that I had not yet provided that information. You should have
received this information through another e-mail thread. See also
http://lists.infradead.org/pipermail/linux-nvme/2018-October/020493.html.

To do that, you have to understand what recursion is valid (I'm guessing
there's some sort of layering involved), and I'm far from understanding
anything about the code that triggered this report.

I don't think there is any kind of recursion involved in the NVMe code
that triggered the lockdep complaint. Sagi, please correct me if I got this
wrong.

I commented on the original thread. I'm not sure it qualifies as a
recursion, but in that use-case, when priv->handler_mutex is taken
it is possible that other priv->handler_mutex instances are taken but
are guaranteed not to belong to that priv...