[sheepdog] [PATCH v2] sheep: get current nodes and vnodes from cache

[Christoph Hellwig]

On Tue, May 29, 2012 at 10:56:22AM +0800, yaohaiting.wujue at gmail.com wrote:
> +	if (epoch == sys_epoch()) {
> +		rw->cur_nr_nodes = sys->nr_nodes;
> +		memcpy(rw->cur_nodes, sys->nodes, sizeof(rw->cur_nodes));
> +		rw->cur_vnodes = get_vnode_info();

all this needs to be called from the main thread.  Give me a bit more
time and I'll send a patch that avoids the read for the old epoch as
well.