mtab: move toward requiring /etc/mtab to be a symbolic link

This changes the mtab service in the following way:

- If /etc/mtab is a symbolic link, success is returned.
- If /etc is not writable, we warn that we could not update /etc/mtab
  and return success.
- If /etc/mtab does not exist, we create a symbolic link from
  /etc/mtab to /proc/self/mounts.
- Otherwise, we warn that updating /etc/mtab as a file is
  deprecated and continue to update it after outputting instructions to
  the user for how to move it to a symbolic link.

0 files changed, 0 insertions, 0 deletions