On Mon, Mar 19, 2018 at 10:53:50AM -0600, Keith Busch wrote: > If a task is holding a reference to a namespace on a removed controller, > the head will not be released. If the same controller is added again > later, its namespaces may not be successfully added. Instead, the user > will see kernel message "Duplicate IDs for nsid <X>". > > This patch fixes that by skipping heads that don't have namespaces when > considering if a new namespace is safe to add. Delayed reference strike once again, sigh. Looks fine: Reviewed-by: Christoph Hellwig <hch@xxxxxx>