osd: Determine if compatibility is required due to back level OSDs

fixes: #7039

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Fix problems in ReplicatedPG::do_op() logic

Fix assert(is_degraded_object(soid)) in ReplicatedPG::wait_for_degraded_object()
  Use last_backfill_started as the backfill line
  Handle uncommon case of multi op source after backfill line and target before
  backfill line and !is_degraded_object().
  Include backfill line itself for before_backfill (<= instead of <)

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Return false for func that returns bool

Signed-off-by: David Zafman <david.zafman@inktank.com>
messages, os, osd: Clean-up g/hobject_t MAX handling

Add check of is_max() before updating an unset pool
Use efficient is_max() instead of compare with hobject::get_max()

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Recovery reservations need to include backfill peers

Caused by 86e4fd4f7a9848511e1bf9ae433fcd3a35a0818f

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Interim working version with backfill reserve state changes

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Change waiting_on_backfill to a set<int>

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Interim backfill changes

Make peer_backfill_info a map which holds a
BackfillInterval for all backfill targets.
Initially see if recover_backfill() can just backfill
the first one and mark them all finished.

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Implement multiple backfill target handling

Fixes: #5858

Signed-off-by: David Zafman <david.zafman@inktank.com>