linux-kernel - Re: RCU-isms in fs/nfs/delegation.c

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Message-ID: <32174.1271753314@redhat.com>
Date:	Tue, 20 Apr 2010 09:48:34 +0100
From:	David Howells <dhowells@...hat.com>
To:	Trond Myklebust <Trond.Myklebust@...app.com>
Cc:	dhowells@...hat.com, paulmck@...ux.vnet.ibm.com,
	linux-nfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: RCU-isms in fs/nfs/delegation.c

Trond Myklebust <Trond.Myklebust@...app.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
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