Add remarks about two additional stratisd improvements

Signed-off-by: mulhern <amulhern@redhat.com>

content/stratis-release-notes-3.0.0.md

@@ -66,9 +66,18 @@ interpreted as two different devices and an error would be returned when
 different paths are canonicalized eagerly, and converted into a single
 canonical representation of the device, `stratisd` initializes the device only
 once, and no error is returned.
+* Previously, `stratisd` did not report all existing object paths in the
+result of a D-Bus Introspect() call. This was due to a bug in version
+0.9.1 and previous of `stratisd`'s dbus-tree dependency. `stratisd` now
+requires dbus-tree 0.9.2, so all nodes are reported.
 
 
 Other `stratisd` improvements:
+* Previously, `stratisd` relied entirely on udev information when deciding
+whether a storage device was not in use by another application and could
+safely be overwritten with Stratis metadata. Now, it performs a supplementary
+check using libblkid and exits with an error if libblkid reports that the
+device is in use.
 * Handling of errors returned by internal methods is improved; a chaining
 mechanism has been introduced and the error chains can be scrutinized
 programatically to identify expected scenarios like rollback failures.