contrib/dracut: 90: mount essential datasets under root

This partly mirrors what the i-t script does (though that mounts all
children, recursively) ‒ /etc, /usr, /lib*, and /bin are all essential,
if present, to successfully invoke the real init, which will then mount
everything else it might need in the right order

The following extreme-case set-up boots w/o issues now:
  /               zoot            zfs  rw,relatime,xattr,noacl
  ├─/etc          zoot/etc        zfs  rw,relatime,xattr,noacl
  ├─/usr          zoot/usr        zfs  rw,relatime,xattr,noacl
  │ └─/usr/local  zoot/usr/local  zfs  rw,relatime,xattr,noacl
  ├─/var          zoot/var        zfs  rw,relatime,xattr,noacl
  │ ├─/var/lib    zoot/var/lib    zfs  rw,relatime,xattr,noacl
  │ ├─/var/log    zoot/var/log    zfs  rw,relatime,xattr,posixacl
  │ ├─/var/cache  zoot/var/cache  zfs  rw,relatime,xattr,noacl
  │ └─/var/tmp    zoot/var/tmp    zfs  rw,relatime,xattr,noacl
  ├─/home         zoot/home       zfs  rw,relatime,xattr,noacl
  │ └─/home/nab   zoot/home/nab   zfs  rw,relatime,xattr,noacl
  ├─/boot         zoot/boot       zfs  rw,relatime,xattr,noacl
  ├─/root         zoot/home/root  zfs  rw,relatime,xattr,noacl
  ├─/opt          zoot/opt        zfs  rw,relatime,xattr,noacl
  └─/srv          zoot/srv        zfs  rw,relatime,xattr,noacl

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Ahelenia Ziemiańska <[email protected]>
Closes #11898

0 files changed, 0 insertions, 0 deletions