In rxrpc_activate_channels(), the connection cache state is checked outside
of the lock, which means it can change whilst we're waking calls up,
thereby changing whether or not we're allowed to wake calls up.
Fix this by moving the check inside the locked region. The check to see if
all the channels are currently busy can stay outside of the locked region.
Whilst we're at it:
(1) Split the locked section out into its own function so that we can call
it from other places in a later patch.
(2) Determine the mask of channels dependent on the state as we're going
to add another state in a later patch that will restrict the number of
simultaneous calls to 1 on a connection.
Signed-off-by: David Howells <dhowells@redhat.com>
2629c7fa7c