NewDreamNetwork/ceph — comment on commit d68f0de3ea848efb5ebc47ae50721c604d14c0a1
File: src/rgw/rgw_rados.cc line 1010
By yehudasa:

First, it'll only happen if there already existed an object before. Otherwise we wouldn't reach that point.

So we have a scenario where we have file 'foo', and then we call in parallel to:
- remove foo
- rewrite foo

So there can be exactly two outcomes for this:
- foo exists, both clients succeeded
- foo doesn't exist, both clients succeeded.

There is another scenario that we should examine:
- remove foo
- remove foo

This scenario isn't really interesting, but anyhow, In this case we'd expect one of the clients to succeed and another one to fail (ENOENT). We'll behave the same in this case too.