Introduce proper locking for the libzfs namespace access.
You can view, comment on, or merge this pull request online at:
https://github.com/openzfs/openzfs/pull/433
-- Commit Summary --
* 8544 libzfs namespace needs proper locking
-- File Changes --
M usr/src/lib/libzfs/common/libzfs_
What I mean is that people are probably used to the fact that this command
blindly zeroes 512KiB at the beginning and the end of the disk and may (ab)use
that property in a way or another (e.g. in an install script to wipe other
kinds of metadata - shame on me, I remember having done that myself
