mksnap_ffs(8) is not working while chrooted

[Kirk McKusick]

> From: Maxim Sobolev <sobomax at freebsd.org>
> Date: Tue, 11 Apr 2017 13:22:08 -0700
> Subject: Re: mksnap_ffs(8) is not working while chrooted
> To: Kirk McKusick <mckusick at mckusick.com>
> 
> Kirk, actually it turns out this is not too difficult to work around this
> issue completely in userland. Please see the patch attached, should be
> relatively bulletproof as it actually verifies fsid of whatever it finds
> with the fsid of the target FS. Please let me know if there are any
> objections to include it into the base system.
> 
> Thanks!
> -Maxim

With your change to verify the matching fsid's, I am fine with your
putting this change into the base system.

	Kirk McKusick