C: pipefs per-net operations helper introduced During per-net pipes creation and destruction we have to make sure, that pipefs sb exists for the whole creation/destruction cycle. This is done by using special mutex which controls pipefs sb reference on network namespace context. Helper consists of two parts: first of them (rpc_get_dentry_net) searches for dentry with specified name and returns with mutex taken on success. When pipe creation or destructions is completed, caller should release this mutex by rpc_put_dentry_net call. Signed-off-by: Stanislav Kinsbursky Signed-off-by: Trond Myklebust 8}@”Ÿ;x