filesystem: revamp module (#2472)

* revamp filesystem module to prepare next steps

* pass all commands to module.run_command() as lists
* refactor grow() and grow_cmd() to not need to override them so much
* refactor all existing get_fs_size() overrides to raise a ValueError if
  not able to parse command output and return an integer.
* override MKFS_FORCE_FLAGS the same way for all fstypes that require it
* improve documentation of limitations of the module regarding FreeBSD
* fix indentation in DOCUMENTATION
* add/update function/method docstrings
* fix pylint hints

filesystem: refactor integration tests

* Include *reiserfs* and *swap* in tests.
* Fix reiserfs related code and tests accordingly.
* Replace "other fs" (unhandled by this module), from *swap* to *minix*
  (both mkswap and mkfs.minix being provided by util-linux).
* Replace *dd* commands by *filesize* dedicated module.
* Use FQCNs and name the tasks.
* Update main tests conditionals.

* add a changelog fragment

* Apply suggestions from code review

Co-authored-by: Felix Fontein <felix@fontein.de>

* declare variables as lists when lists are needed

* fix construction without useless conversion

Co-authored-by: Felix Fontein <felix@fontein.de>

tests/integration/targets/filesystem/tasks/create_fs.yml

@@ -1,43 +1,58 @@
-- name: filesystem creation
-  filesystem:
+---
+- name: "Create filesystem"
+  community.general.filesystem:
     dev: '{{ dev }}'
     fstype: '{{ fstype }}'
   register: fs_result
 
-- assert:
+- name: "Assert that results are as expected"
+  ansible.builtin.assert:
     that:
       - 'fs_result is changed'
       - 'fs_result is success'
 
-- command: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+- name: "Get UUID of created filesystem"
+  ansible.builtin.command:
+    cmd: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+  changed_when: false
   register: uuid
 
 - name: "Check that filesystem isn't created if force isn't used"
-  filesystem:
+  community.general.filesystem:
     dev: '{{ dev }}'
     fstype: '{{ fstype }}'
   register: fs2_result
 
-- command: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+- name: "Get UUID of the filesystem"
+  ansible.builtin.command:
+    cmd: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+  changed_when: false
   register: uuid2
 
-- assert:
+- name: "Assert that filesystem UUID is not changed"
+  ansible.builtin.assert:
     that:
-      - 'not (fs2_result is changed)'
+      - 'fs2_result is not changed'
       - 'fs2_result is success'
       - 'uuid.stdout == uuid2.stdout'
 
-- name: Check that filesystem is recreated if force is used
-  filesystem:
+- name: "Check that filesystem is recreated if force is used"
+  community.general.filesystem:
     dev: '{{ dev }}'
     fstype: '{{ fstype }}'
     force: yes
   register: fs3_result
 
-- command: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+- name: "Get UUID of the new filesystem"
+  ansible.builtin.command:
+    cmd: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+  changed_when: false
   register: uuid3
 
-- assert:
+- name: "Assert that filesystem UUID is changed"
+  # libblkid gets no UUID at all for this fstype on FreeBSD
+  when: not (ansible_system == 'FreeBSD' and fstype == 'reiserfs')
+  ansible.builtin.assert:
     that:
       - 'fs3_result is changed'
       - 'fs3_result is success'
@@ -46,24 +61,31 @@
 
 - when: 'grow|bool and (fstype != "vfat" or resize_vfat)'
   block:
-    - name: increase fake device
-      shell: 'dd if=/dev/zero bs=1M count=1 >> {{ image_file }}'
+    - name: "Increase fake device"
+      community.general.filesize:
+        path: '{{ image_file }}'
+        size: '{{ fssize | int + 1 }}M'
 
-    - name: Resize loop device for LVM
-      command: losetup -c {{ dev }}
+    - name: "Resize loop device for LVM"
+      ansible.builtin.command:
+        cmd: 'losetup -c {{ dev }}'
       when: fstype == 'lvm'
 
-    - name: Expand filesystem
-      filesystem:
+    - name: "Expand filesystem"
+      community.general.filesystem:
         dev: '{{ dev }}'
         fstype: '{{ fstype }}'
         resizefs: yes
       register: fs4_result
 
-    - command: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+    - name: "Get UUID of the filesystem"
+      ansible.builtin.command:
+        cmd: 'blkid -c /dev/null -o value -s UUID {{ dev }}'
+      changed_when: false
       register: uuid4
 
-    - assert:
+    - name: "Assert that filesystem UUID is not changed"
+      ansible.builtin.assert:
         that:
           - 'fs4_result is changed'
           - 'fs4_result is success'
@@ -74,14 +96,15 @@
       (fstype == "xfs" and ansible_system == "Linux" and
       ansible_distribution not in ["CentOS", "Ubuntu"])
   block:
-    - name: Check that resizefs does nothing if device size is not changed
-      filesystem:
+    - name: "Check that resizefs does nothing if device size is not changed"
+      community.general.filesystem:
         dev: '{{ dev }}'
         fstype: '{{ fstype }}'
         resizefs: yes
       register: fs5_result
 
-    - assert:
+    - name: "Assert that the state did not change"
+      ansible.builtin.assert:
         that:
           - 'fs5_result is not changed'
           - 'fs5_result is succeeded'