[ovs-dev] [PATCH 07/10] datapath: Add casts for direct freeing of RCU data.

Ben Pfaff blp at nicira.com
Wed Dec 29 18:05:01 UTC 2010


On Tue, Dec 28, 2010 at 08:50:45PM -0800, Jesse Gross wrote:
> There are a few places where we have two levels of RCU protected
> data to allow the second level to change independently of the
> first.  Although the two pieces are independent, they have the
> same users and the same lifetime.  This means that we directly
> free the second level when it is safe to free the first.  This
> implies that we directly access RCU-protected data, which is
> generally not allowed.  There are locks to check, so none of the
> normal RCU functions apply.  Instead, this adds an explicit cast.
> 
> Found with sparse.
> 
> Signed-off-by: Jesse Gross <jesse at nicira.com>

Well, they don't have exactly the same lifetime or there would be no
point in RCU-protecting the inner part.  Rather, if the outer part
dies then the inner part dies too.

Acked-by: Ben Pfaff <blp at nicira.com>




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