Strange behavior of .zfs/snapshot/* directories in respect to ".." path.

[Lev Serebryakov]

 I have some filesystem with multiple snapshots. And behavior of "cd .."
in snapshot directories is very strange: when I'm in one of dnapshot
directories "cd ../other" doesn't work and "cd .." brings me to the root
of file system.

$ pwd
/usr/home/lev
$ cd .zfs/snapshot
$ pwd
/usr/home/lev/.zfs/snapshot
$ ls | tail -2
weekly-2017-05-06_05.17.18--1y
weekly-2017-05-13_04.18.37--1y
$ cd weekly-2017-05-06_05.17.18--1y
$ pwd
/usr/home/lev/.zfs/snapshot/weekly-2017-05-06_05.17.18--1y
$ cd ../weekly-2017-05-13_04.18.37--1y
../weekly-2017-05-13_04.18.37--1y: No such file or directory.
$ pwd
/usr/home/lev/.zfs/snapshot/weekly-2017-05-06_05.17.18--1y
$ cd ..
$ pwd
/usr/home/lev
$ uname -i -K -v
FreeBSD 11.1-PRERELEASE #16 r318576: Sat May 20 22:30:06 MSK 2017
root at blob.home.serebryakov.spb.ru:/usr/obj/usr/src/sys/BLOB  BLOB 1100513
$

 Is it Ok?

-- 
// Lev Serebryakov