Add test for volume/filesystem resize

Based on @yizhanglinux's code in linux-system-roles#139.

Remove a disabled resize test from tests_lvm_errors where it does not belong
anymore.

tests/tests_lvm_errors.yml

@@ -341,28 +341,6 @@
                       not blivet_output.changed }}"
             msg: "Unexpected behavior w/ existing data on specified disks"
 
-    - name: Test for correct handling of safe_mode with resize
-      block:
-        - name: Try to resize in safe mode
-          include_role:
-            name: storage
-          vars:
-            storage_pools:
-              - name: testpool1
-                type: lvm
-                disks: "{{ unused_disks }}"
-                volumes:
-                  - name: testvol1
-                    fs_type: 'ext4'
-                    size: '2g'
-
-        - name: Verify the output
-          assert:
-            that: "{{ not blivet_output.failed and blivet_output.changed }}"
-            msg: "Unexpected behavior w/ existing data on specified disks"
-
-      when: false
-
     - name: Test for correct handling of safe_mode with existing pool
       block:
         - name: Try to create LVM pool on disks that already belong to an existing pool

tests/tests_resize.yml

@@ -0,0 +1,63 @@
+- hosts: all
+  vars:
+    mount_location: '/opt/test1'
+    volume_group_size: '10g'
+    volume_size_before: '5g'
+    volume_size_after: '9g'
+
+  tasks:
+    - include_role:
+        name: storage
+
+    - include_tasks: get_unused_disk.yml
+      vars:
+        min_size: "{{ volume_group_size }}"
+        max_return: 1
+
+    - name: Create one LVM logical volume with "{{ volume_size_before }}" under one volume group
+      include_role:
+        name: storage
+      vars:
+          storage_pools:
+            - name: foo
+              disks: "{{ unused_disks }}"
+              type: lvm
+              volumes:
+                - name: test1
+                  # resizing is currently supported only for ext2/3/4
+                  fs_type: 'ext4'
+                  size: "{{ volume_size_before }}"
+                  mount_point: "{{ mount_location }}"
+
+    - include_tasks: verify-role-results.yml
+
+    - name: Change volume_size to "{{ volume_size_after }}"
+      include_role:
+        name: storage
+      vars:
+          storage_pools:
+            - name: foo
+              type: lvm
+              disks: "{{ unused_disks }}"
+              volumes:
+                - name: test1
+                  fs_type: 'ext4'
+                  size: "{{ volume_size_after }}"
+                  mount_point: "{{ mount_location }}"
+
+    - include_tasks: verify-role-results.yml
+
+    - name: Clean up
+      include_role:
+        name: storage
+      vars:
+          storage_pools:
+            - name: foo
+              disks: "{{ unused_disks }}"
+              state: absent
+              volumes:
+                - name: test1
+                  size: "{{ volume_size_after }}"
+                  mount_point: "{{ mount_location }}"
+
+    - include_tasks: verify-role-results.yml