quatactl(2) mechanism. (Read-only at this point, however.)
In particular, this is to allow rpc.rquotad query quotas
for NFS mounts, allowing users to see their quotas on the
hosts using the datasets.
The changes specifically:
* Add new RPC entry points for querying quotas.
* Changes the library routines to allow non-UFS quotas.
* Changes rquotad to check for quotas on mounted filesystems,
rather than being limited to entries in /etc/fstab
* Lastly, adds a VFS entry-point for ZFS to query quotas.
Note that this makes one unavoidable behavioural change: if quotas
are enabled, then they can be queried, as opposed to the current
method of checking for quotas being specified in fstab. (With
ZFS, if there are user or group quotas, they're used, always.)
Reviewed by: delphij, mav
Approved by: mav
Sponsored by: iXsystems Inc
Differential Revision: https://reviews.freebsd.org/D15886
64-bit quota sizes by scaling down the sizes by the minimum amount
necessary to fit in a 32-bit field and then upscale the filesystem
block size to compensate. For example, if the hard block limit is
0x300000008 then we set the hard block limit to 0xA0000002 and claim
that the blocksize is 4 * DEV_BSIZE. This will lose the minimal
amount of information thus delivering nearly correct answers.
