illumos gate

While investigating #6562, I noticed this test case:

zfs create rpool/foo
zfs set refquota=10M rpool/foo
sync
yes > /rpool/foo/fill-er-up
sync
zfs snapshot rpool/foo@1
zfs send -R rpool/foo@1 | zfs recv rpool/bar
echo "" 
zfs list -pt all | egrep "NAME|foo|bar" 
zfs get -p refquota rpool/foo
zfs get -p refquota rpool/bar

Will create "rpool/bar", but it will NOT set the refquota, and it will complain about doing so.

Two possible solutions are:

1.) The zfs_ioc_recv() code can special-case refquota so as to take into account the one-transaction overage like 6562 does for incrementals.

or

2.) refquota in-kernel ALWAYS accounts for the overage, and for "zfs set", the libzfs code takes over the bounds checking from the zfs(1M) command.