client: clarify which kind of msg in debug output

Signed-off-by: Sage Weil <sage@inktank.com>
client: drop obsolete comment

Signed-off-by: Sage Weil <sage@inktank.com>
client: only signal session waiters on open and close

Signed-off-by: Sage Weil <sage@inktank.com>
client: remove unused MetaSession::was_stale

Signed-off-by: Sage Weil <sage@inktank.com>
client: fix remaining s->inst users to use s->con

Signed-off-by: Sage Weil <sage@inktank.com>
client: validate/lookup mds session in each message handler

For every message handler, look up the MetaSession by int mds and verify
that the Connection* matches properly.  If so, proceed; otherwise, discard
the message.

In the future, we probably want to link the MetaSession to the Connection's
priv field, but that can come later.

Clean up a bunch of submethods that take int mds while we're here.

Signed-off-by: Sage Weil <sage@inktank.com>
client: fix wake_inode_waiters() arg

Signed-off-by: Sage Weil <sage@inktank.com>
client: fix trim_caps() args

Signed-off-by: Sage Weil <sage@inktank.com>
client: clean up useless MetaSession lookups

Signed-off-by: Sage Weil <sage@inktank.com>
client: fix kick_flushing_caps() args

Signed-off-by: Sage Weil <sage@inktank.com>