lxc.container.conf(5): update guidance for lxc.mount.entry mount target

For years it has been best practice to use a relative path as
the mount target.  But the manpage hasn't reflect that.  Fix it.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Dwight Engen <dwight.engen@oracle.com>

diff --git a/doc/lxc.container.conf.sgml.in b/doc/lxc.container.conf.sgml.in
index 6e9688971f7a1096f9194ace3988ded27cdcb398..3e2208bed697969eaaa3c352e95fa3dcf8ebbc27 100644 (file)
--- a/doc/lxc.container.conf.sgml.in
+++ b/doc/lxc.container.conf.sgml.in
@@ -672,13 +672,21 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
            <para>
              specify a file location in
              the <filename>fstab</filename> format, containing the
-             mount information. If the rootfs is an image file or a
-             block device and the fstab is used to mount a point
-             somewhere in this rootfs, the path of the rootfs mount
-             point should be prefixed with the
-             <filename>@LXCROOTFSMOUNT@</filename> default path or
-             the value of <option>lxc.rootfs.mount</option> if
-             specified. Note that when mounting a filesystem from an
+             mount information.  The mount target location can and in
+             most cases should be a relative path, which will become
+             relative to the mounted container root.  For instance,
+            </para>
+<screen>
+proc proc proc nodev,noexec,nosuid 0 0
+</screen>
+            <para>
+             Will mount a proc filesystem under the container's /proc,
+             regardless of where the root filesystem comes from.  This
+             is resilient to block device backed filesystems as well as
+             container cloning.
+            </para>
+            <para>
+             Note that when mounting a filesystem from an
              image file or block device the third field (fs_vfstype)
              cannot be auto as with
               <citerefentry>