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From: David Howells <dhowells@redhat.com>
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To: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: dhowells@redhat.com, paulmck@linux.vnet.ibm.com, linux-nfs@vger.kernel.org,
       linux-kernel@vger.kernel.org
Subject: Re: RCU-isms in fs/nfs/delegation.c
Date: Tue, 20 Apr 2010 09:48:34 +0100
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Trond Myklebust <Trond.Myklebust@netapp.com> wrote:

> +		nfs_inode_set_delegation(inode, cred, res);
> +	}
> +out:
> +	rcu_read_unlock();
>  }

I think this is wrong.  nfs_inode_set_delegation() may sleep as it calls
kmalloc() with GFP_KERNEL - but you still have the RCU read lock held.  I
think you need to drop the RCU read lock before calling it.

David