DOCS-11447: Improve docs on linearizable read concern

Author: ravindk89

source/includes/extracts-concurrency-consistency-recency.yaml

@@ -134,10 +134,12 @@ content: |
 ---
 ref: no-journaling-rollback
 content: |
+   
    With :rsconf:`writeConcernMajorityJournalDefault` set to ``false``,
-   MongoDB will not wait for
-   :writeconcern:`w: "majority" <"majority">` writes to be durable
-   before acknowledging the writes. As such, :writeconcern:`"majority"`
-   write operations could possibly
-   roll back in the event of a loss of a replica set member.
+   MongoDB does not wait for :writeconcern:`w: "majority" <"majority">`
+   writes to be written to the on-disk journal before acknowledging the
+   writes. As such, :writeconcern:`majority` write operations could
+   possibly roll back in the event of a transient loss (e.g. crash and
+   restart) of a majority of nodes in a given replica set.
+
 ...

source/reference/read-concern.txt

@@ -94,13 +94,16 @@ The following read concern levels are available:
 
    * - .. readconcern:: "linearizable"
 
-     - The query returns data that reflects all successful writes
-       issued with a write concern of :writeconcern:`"majority"` *and*
-       acknowledged prior to the start of the read operation. For
-       replica sets that run with
-       :rsconf:`writeConcernMajorityJournalDefault` set to true,
-       linearizable read concern returns data that will never be rolled
-       back. 
+     - The query returns data that reflects all successful 
+       majority-acknowledged writes that completed prior to the start
+       of the read operation. The query may wait for concurrently
+       executing writes to propagate to a majority of replica
+       set members before returning results.
+
+       If a majority of your replica set members crash and restart after
+       the read operation, documents returned by the read operation are
+       durable if :rsconf:`writeConcernMajorityJournalDefault` is set to
+       the default state of ``true``.
 
        .. include:: /includes/extracts/no-journaling-rollback.rst