The system call fstatvfs64 (get the filesystem stats from file descriptor) is broken in Docker Desktop. When the file is open on a Windows mapped volume, the free space is returned as 0. The file’s location passed to statvfs64 (filesystem stats by path) results in the correct amount of free space reported.
The issue occurs from 184.108.40.206 to 220.127.116.11 .
The issue does not occur in earlier versions.
The environment is Windows 10 with the latest updates as of 3/20/2020.