ReFS parallel (multithreaded) clones of single source file can fail

[erikmav]

See microsoft/CopyOnWrite#3 where creating clones can return success but the file is all zeroes (i.e. region clone did not actually take effect). PR in which I added serialization based on source path to make things fully stable: microsoft/CopyOnWrite#6

I don't have a solution for this. Working on filing an issue with Windows team but any fix would be a long time coming.

[erikmav]

Also see cross-process mutex implementation in microsoft/CopyOnWrite#9

[erikmav]

Tracking and more details on the bug in microsoft/CopyOnWrite#12