Merge pull request #10257 from chhabaramesh/extent_alloc

os/bluestore: extent alloc functionality for stupid and bitmap allocator

Mark's Comments:
This passed "ceph_test_objectstore --gtest_filter=*/2".
This PR appears to result in a large sequential write performance increase (Up to ~3.5X), and may contribute to a small random write performance increase as well.

Reviewed-by: Mark Nelson <mnelson@redhat.com>

diff --cc src/os/bluestore/BlueStore.cc
Simple merge