Cannot rm files when ZFS is full

[grarpamp]

Yep, the cp /dev/null <file> works to truncate. So I can deal with it.
Yep, everything is snapshotted.
Yep, this is a Sun issue not a FreeBSD one. FreeBSD should just stay
current with the versions and the minimum needed to port... fbsd dev
time is valuable elsewhere.
I do remember reading about copy on write, d-oh :)
ZFS should probably keep track of the largest extent needed to effect
any given operation and reserve that behind the scenes. If it took n
bytes to create something sans data, it'll probably take n bytes to
modify it.
Quotas and things might work though the user under quota might run
into the same problem. Who knows.

Thx CW, et al.