[CentOS] xfs_quota problem

I brought this up a month or so ago, and am just back to it: I've got a
large RAID filesystem, mounted in one location, /<mntpt>/x/workspace, but
we're having project directories that are under that magically appear
under /workspace, as /workspace/projname1.... I need to set up xfs quotas
by project, and I can't seem to find the right syntax.

CentOS 6. Note that it's *project* quotas, which according to the docs and
man pages do not need to be a filesystem.

Too much googling, with high a noise to signal ratio.

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