osd/ReplicatedPG: fix whiteouts for other cache mode

We were special casing WRITEBACK mode for handling whiteouts; this needs to
also include the FORWARD and READONLY modes.  To avoid having to list
specific cache modes, though, just check != NONE.

Fixes: #8296
Backport: firefly
Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 3e387d62ed95898db8a7d7163c2bacc363b8f617)
osd/ReplicatedPG: fix trim of in-flight hit_sets

We normally need to stat the hit_set to know how many bytes to adjust the
stats by.  If the hit_set was just written, we will get ENOENT.

Get the obc instead, which will either get the in-memory copy (because the
repop is still in flight) or load it off of disk.

Fixes: #8283
Backport: firefly
Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 72fdd557c35cb721d4b502c5a8f68c878f11a19c)
mon/MonClient: remove stray _finish_hunting() calls

Callig _finish_hunting() clears out the bool hunting flag, which means we
don't retry by connection to another mon periodically.  Instead, we send
keepalives every 10s.  But, since we aren't yet in state HAVE_SESSION, we
don't check that the keepalives are getting responses.  This means that an
ill-timed connection reset (say, after we get a MonMap, but before we
finish authenticating) can drop the monc into a black hole that does not
retry.

Instead, we should *only* call _finish_hunting() when we complete the
authentication handshake.

Fixes: #8278
Backport: firefly, dumpling
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Joao Eduardo Luis <joao.luis@inktank.com>
(cherry picked from commit 77a6f0aefebebf057f02bfb95c088a30ed93c53f)