Re: DMAPI rights

[Dean Roehrich <roehrich@sgi.com>]

>From:  "James A Goodwin" <jagoodwi@us.ibm.com>
>Dean,
>
>Since XFS DMAPI doesn't implement rights, rights obviously can't be
>attached to tokens.  Does this mean that every call requiring a certain
>level of 'rights' must be called using DM_NO_TOKEN?

No, we do attach rights to tokens.  It's just that XFS itself knows nothing
about the rights and once you step out of the DMAPI code and into the XFS code
your rights won't be honored.

A dm_request_right/dm_release_right will do a hold/rele on the vnode, at
least.  Other than that, the rights stuff is a no-op.

There's a write-up on rights in fs/xfs_dmapi/dmapi_event.c, though I don't
know how much of that reflects the current code.

Dean