Re: [PATCH] NFS: Fix RCU warnings in nfs_inode_return_delegation_noreclaim() [ver #2]

Paul E. McKenney
2010-03-31T15:17:10Z

On Wed, Mar 31, 2010 at 03:04:33PM +0100, David Howells wrote:
> Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:
>
> > How about Eric's suggestion of rcu_dereference_protected()? That name
> > doesn't imply a lock, which as you say above, isn't always needed to
> > keep the structure from changing.
>
> But 'protected' from what or by what?

Protected by something that the caller did, be it holding the the correct
lock, operating on it during initialization before other CPUs have access
to it, operating on it during cleanup after other CPUs' access has been
revoked, or whatever.

Thanx, Paul